section abstracts

7/24/2019 Section Abstracts

1/35

The University of Quee

Au

sland

tralia

17thI

Coo

HR Inte

ling Tow


2/35

17thIAHR International Conference on Cooling Tower and Heat Exchanger, 7-11, September 2015, Gold Coast, Queensland, Australia

1

Opening session

Chair: Dr Kamel Hooman

The University of Queensland, Australia

OVERVIEW OF NSF-EPRI COLLABORATIVELY FUNDED ADVANCED DRY COOLING PROJECTSDr. Jessica Shi, Sr. Technical Leader/Manager; Dr. Sean Bushart, Director; and Dr. Bob Goldstein, Sr. Technical Executive

Electric Power Research Institute

Dr. Sumanta Acharya, Former NSF Program Director

University of Memphis

US thermoelectric power plants contribute to about 40% of nations fresh water withdrawals, primarily due to cooling. While

recirculating cooling towers only account for approximately 3% of US fresh water consumption, their water use rates may not be

sustainable in some locations. In addition, thermal discharges and water intake for once-through cooling face increasing regulatory

scrutiny. Furthermore, siting of new capacity is challenged by water supply constraints. Therefore, breakthrough cooling

technology development to minimize fresh water use is emerging as a top priority research topic for all types of thermoelectric

plants.

To develop viable game changing solutions, the National Science Foundation (NSF) and Electric Power Research Institute (EPRI)

jointly released a $6 M solicitation on advancing dry cooling technologies in 2013. The presentation will highlight several

technologies being developed through this collaboration, including alternative dry cooling concepts, such as indirect dry cooling

towers with phase-change materials as intermediate coolants, novel heat driven micro emulsion-based adsorption green chillers for

steam condensation, on-demand sweating-boosted air cooled heat-pipe condensers for green power plants, direct contact heat

exchange and absorption refrigeration based on green non-volatile ionic liquids for enhanced dry cooling of thermoelectric power

plants, ejector cooling system with evaporation/condensation compact condenser, and integrated innovative heat pipe dry cooling

towers; and enhancement concepts for the currently used air cooled condensers, such as advanced air cooled condensers withvortex-generator arrays between fins, auto flutter enhanced air cooled condensers, nanostructure enhanced air-cooled steam

condensers, and porous structures with 3D manifold for ultra-compact air side dry cooling.

OVERVIEW OF EMERGING TECHNOLOGIES RESEARCH IN BUILDING EQUIPMENT RESEARCH

Pradeep Bansal

Group at Oak Ridge National Laboratory

Abstract: The Building Equipment Research Group at Oak Ridge National Laboratory (ORNL) is working on emerging

technologies that improve consumer health and productivity such as heating, cooling, hot water, and refrigeration. The research

is funded by the Building Technology Office (BTO) of the Department of Energy (USA) whose mission is to save 50% energy

with 2010 baseline by 2030, and advance the state of the art in building equipment research well beyond that the private sector is


3/35


2

willing to invest. The talk will present an overview of some of the research on emerging technologies related to appliances, water

heaters, heating/cooling, and supermarket refrigeration systems.

COOLING TOWER DESIGN FOR COAL-FIRED POWER PLANTS

Reinhard HARTE1,2

1Bergische Universitaet Wuppertal, Germany

2Kraetzig & Partner Engineering Consultants GmbH Bochum, Germany

Keywords: cooling tower shell, flue-gas inflow, stability, nonlinear shell analysis.

Abstract: It is a specific feature of German design for coal-fired power plants that the cleaned flue-gas is conducted into the

cooling tower and then forwarded to the atmosphere via the natural updraft in the Natural Draft Cooling Tower NDCT. The

lecture will summarize the benefits and drawbacks of this technology and will present strategies to optimize both the

thermodynamic updraft and the structural behavior. The paper will further present innovations of the current edition of the VGB

Guideline Structural Design of Cooling Towers, which since many years has served as the theoretical and practical tool to

design and build cooling towers all over the world.

PERFORMANCE EVALUATION AND DESIGN OF A NEW COOLING TOWER SPRAY SYSTEM FOR UNIFORM

WATER DISTRIBUTION

Danil ROUX1and Hanno C. R.REUTER

1Stellenbosch University, Stellenbosch, South Africa

Keywords: Spray nozzle, uniform water distribution, cooling tower performance.

Abstract: The performance of wet cooling towers can be improved by installing sprayers that distribute the cooling wateruniformly onto the fill whilst operating at a low pressure head. This paper presents the methodology that was followed to design a

new cooling tower spray nozzle. The fluid dynamics of an orifice nozzle, such as the effect of a change in pressure head, spray

angle, spray height, orifice diameter and wall thickness on drop diameter and spray distance, is experimentally investigated and

ultimately a model with which a spray nozzle can be designed is presented. The manufacture and testing of a prototype spray

nozzle show that it is possible to enhance the performance of sprayers and thus wet cooling towers by means of the methods

presented. Session I

OVERVIEW OF COOLING TOWER RESEARCH IN QGECE, UQ

Zhiqiang Guan

QGECE, The University of Queensland

Abstract: The University of Queensland (UQ) has developed several hybrid cooling technologies for renewable power plants,

especially for geothermal and concentrated solar thermal (CST) plants. The modelling results show that these novel technologies

will increase the performance of a dry cooling system when ambient temperature is high with low cost on tower structure

construction. The hybrid cooling technologies developed by UQ include: solar hybrid, water hybrid and windbreak wall hybrid

natural draft cooling towers as well as the innovative structural design of tower.

In a solar hybrid natural draft dry cooling tower, solar roofs are added and arranged radically at the base of the tower, and the

heat exchangers are placed vertically at the outside edge of the solar roofs. The system exploits the solar energy during thehottest periods at which the conventional dry cooling tower would suffer the lowest performance.


4/35


3

The water hybrid system uses a small amount of water to increase the cooling performance of natural draft dry cooling

towers (NDDCTs) during periods of high ambient temperatures. In this system, water is introduced into the inlet air stream

of a dry cooling tower. The water evaporates and reduces the entering air dry bulb temperature theoretically to its wet bulb

temperature.

A simple but very effective windbreak wall has been introduced to improve the performance of small NDDCTs under

crosswind. These walls are used to divert crosswind flow through the heat exchangers to improve the performance of thetower. When there is crosswind, the walls stop the crosswind flowing across the bottom, change the direction of the

crosswind, and force it flow through heat exchanger. Since more air flow through the heat exchanger, it improves the

performance of the tower.

QGECE develop a novel steel cooling tower structure design for renewable small power plants. In this design, construction

cost can be saved comparing to the traditional reinforced (RC) concreate cooling tower.

Session I

Cooling Tower

Chair: Dr Pradeep Bansal

Oak Ridge National Laboratory, USA

SHAKING INFINITE COOLING TOWER ALTERNATIVES THROUGH THE SIEVES OF PROJECT AND SITE

CRITERIA

Lawrence THOMAS

Marley Flow Control, Sydney, Australia

Keywords: cooling tower optimization fouling scaling capitalized power modular sustainable.

Abstract: New and old cooling towers alike too often are not optimized to suit to site conditions, physical constraints or plant

operating economics. Manifestation of a poor fit may include production reducing performance, unused capacity, fouling,

corrosion, high maintenance, unnecessary features and unacceptable noise or visible plume. The poor fit can be clear soon after

completion of a new construction and the owner is left wondering why these solvable issues were not dealt with in the equipment

selection. This paper examines a comprehensive optimization and selection process and explains how holistic choices can be

made according to economic criteria within constraints of individual sites. I aim to encourage owners and planners to engage with

cooling tower designers early to develop a detailed tower concept that strikes the right balance of priorities for a specific project.

ON-LINE REFURBISHMENT OF A WET NATURAL DRAUGHT COOLING TOWER

Roger Rusch


5/35


4

Industrial Water Cooling (Pty)Ltd, South Africa

Keywords:Natural, Draught, Cooling, Tower, Refurbishment, On-line, retrofit

Abstract: Yallourn Power Station is located at the eastern end of the Latrobe Valley, approximately 150km east of Melbourne,

Victoria. The Power Station consists of 4 brown coal fired generator units, commissioned from 1973 to 1982. This project was

for the upgrade of the natural draught cooling tower servicing Generating units 3 and 4. The cooling Tower is a single concreteWet Natural Draught Cooling Tower This paper discusses the project scope, project execution as well as the resulting

improvement in the cooling towers thermal performance.

COOLING PERFORMANCE RESEARCH AND OPTIMIZATION ON COOLING TOWER BY SHANDONG

UNIVERSITY, CHINA

Fengzhong SUN, Yuanbin ZHAO, Ming GAO, Yan LI, Lei ZHANG, Dongqiang LV

School of Energy and Power Engineering, Shandong University, Jinan 250061, China

Keywords: Wet cooling tower; Dry cooling tower; Cooling performance; Improvement

Abstract: Focused on the performance optimization of thermal power plant cold end system, Shandong University has been

engaged in cooling performance research and optimization for natural draft wet cooling tower (NDWCT) and natural draft dry

cooling tower (NDDCT). Based on the fundamental principles of heat and mass transfer in tower, the experimental and numerical

platforms for NDWCTs and NDDCTs have been established, so as to study the cooling performance and relevant improvement

mechanisms, which are very beneficial for improving the cooling efficiency of running cooling tower. Effect mechanisms of air

deflectors, cross walls, air guiding ducts, fill and spray layout optimization have been studied and clarified in details for wet

cooling tower, among which air deflectors are also demonstrated to be very beneficial for improving cooling performance of

NDDCTs.

STUDY ON THE COMBUSTION OF POLYMERS WITHIN COOLING TOWERS

Chris BOWMAN, Jia SHENand Richard AULL

North America Bentwood Industries, Reading, PA USA

Keywords: Flame spread, flame retardants, fire risk, polymer combustion, PVC, Polypropylene

Abstract: Due to the continued growth of polymer materials in the fabrication of fills, drift eliminators and even heat exchangers,

the knowledge of their fire risk and flame propagation characteristics becomes more important than ever for the specifying

engineer and ultimate end user. Additionally, cooling tower component manufacturers are using increasingly varied formulations

of polymers in the manufacture of their products so it is prudent to understand whether the current test standards provide the

complete picture of a cooling towers susceptibility to initiating and propagating a fire event.

INVESTIGATIONS OF ADVERSE WIND LOADS ON LARGE COOLING TOWERS UNDER SIX TOWER

COMBINATION

Yaojun GE1, Xu CHEN1, Yuwen LIANG1, Lin ZHAO1

1State Key Lab for Disaster Reduction in Civil Engineering, Tongji University, Shanghai, China

Keywords: Cooling tower, Wind load pattern, Asymmetric distribution, Safety strengthAbstract: Wind-induced pressures were measured on a grouping of six cooling towers during a series of boundary layer wind tunnel

tests which varied among two tower arrangements, three tower spacings and sixteen yaw angles. The circular pressures on the throat


6/35


5

level were statistically analyzed and these pressure distributions can be generally divided into two patterns, i.e. symmetric pattern and

asymmetric pattern, among which the former can be subdivided into 9 forms and the latter 18 forms. The self-developed software for

the design of large cooling towers were adopted to calculate wind effects under the 27 wind loads. The stability coefficient and steel

ratio were chosen as indexes in the comparison of effects induced by different wind load forms. Finally, three symmetric and three

asymmetric wind pressure forms were suggested as the most adverse wind loads among them.

Session II-A

Dry cooling towers

Chair: Professor Dr.-Ing. R. Harte

Bergische Universitaet Wuppertal, Germany


7/35


6

SIMULATION OF THE UQ GATTON NATURAL DRAFT DRY COOLING TOWER

Xiaoxiao Li, Zhiqiang Guan, Hal Gurgenci, Yuanshen Lu


Keywords: Natural draft dry cooling tower (NDDCT), Cooling performance

Abstract:Natural draft dry cooling tower (NDDCT) is an effective cooling technology. The experimental studies of the full scalecooling tower, especially the small size NDDCTs, are still not extensive. To fill this gap, Queensland Geothermal Energy Centre

of Excellence (QGECE) at The University of Queensland has built a 20m high NDDCT. In this paper, the 1D analytical model

and the 3D CFD model of this cooling tower were developed and its cooling performance was investigated at different ambient

temperatures, hot water temperatures and velocities of cross wind. The result shows that the small size NDDCT is suitable for

2~3MW CST power plants. The cooling performance decreases with the increase in the ambient temperature and the decrease in

the hot water temperature. In terms of the cross wind, the heat rejection ratio decreases with the increase of the cross wind velocity

when cross wind velocity is low. However, when velocities of the cross wind become large enough, the heat dumped at the bottom

of the tower can compensate some loss caused by cross wind. The results found in the present paper give reference for planed

experiments.

HEAT TRANSFER AUGMENTATION AND OPIMISATION IN A SOLAR ENHANCED NATURAL DRAFT DRY

COOLING TOWER

M. ODABAEE, M. M. SHANEHCHI and K. HOOMAN

The University of Queensland, Qld 4072, Australia

Keywords: Metal foam, finned-tube, heat exchanger, solar, natural cooling tower

Abstract: Different heat transfer surface extension techniques are considered in order to improve the performance of an air-cooled

heat. The conventional method of extending the heat transfer area by means of fins is compared with a modern technique beingthe application of a thin metal foam layer to the outer surface of the tube. Aiming at maximizing the heat transfer enhancement

and minimizing the total pressure drop, different tube bundle arrangements are numerical investigated by ANSYS-Fluent where

the number of rows and tube spacing are systematically changed. An optimum design is presented for an existing tower to be

equipped with solar panels to afterheat the air leaving the heat exchanger bundles arranged vertically around the tower skirt.

CFD ANALYSIS OF THE WATER SPRAY SYSTEM WITH THE VERTICAL ARRANGED NOZZLE FOR THE PRE-

COOLING IN NATURAL DRAFT DRY COOLING TOWERS

Lin Xia1,2, Zhiqiang Guan2, Hal Gurgenci2and Deyou Liu1

1Hohai University, Nanjing, China

2University of Queensland, Brisbane, Australia

Keywords: Spray cooling, Numerical simulation, Complete evaporation.

Abstract: CFD analysis of the water spray system with the vertical arranged nozzle (VAN) for the inlet air pre-cooling is

presented to improve the performance of a 20m height natural draft cooling tower in UQ Gatton campus. The comparison between

the pre-cooling effect of the horizontal arranged nozzle (HAN) and the VAN shows that when air velocity is small, the pre-cooling

effect of the VAN is much better than that of the HAN. The impact of many physical parameters on the maximum fully evaporated

water flow rate is also investigated. The results are of great significance for the optimization design and operation of the water

spray system.


8/35


7

EXPERIMENTAL RESEARCH FOR PREVENTIVE METHOD AGAINST CROSSWIND EFFECT ON AIRFLOW AT

OUTLET TO ENHANCE THERMAL PERFORMANCE OF LARGE COOLING TOWER

Lei ZHANG1, FengzhongSUN1, MingGAO1

1Shandong University, Jinan, China

Keywords: Cooling towerthermal state model experimentcrosswindthermal performancepreventive method.Abstract: The paper reports thermal state model experiments of natural draft cooling tower (NDCT) to study crosswind effect on

outlet airflow and the preventive method to enhance thermal performance of the cooling tower. The flow patterns of outflow with

and without using the preventive method are presented comparably. Two new indices are introduced to evaluate the quantity of

cold inflow and the homogeneity of heat tranfer on the tower cross section respectively. It can be seen that the biggest ratio of cold

inflow occures at the crosswind velocity of 0.2 m/s, which is 8%~10% of outflow rate. As the crosswind velocity increases, the

ratio of cold inflow decreases gradually. At low crosswind velocities, cold inflow that reduces effective stack height plays more

important role, while at high crosswind velocties, the disturbance of outflow which increases flow resistance is prior to the

reduction of effective stack height. The preventive method capable of stopping cold inflow and making outflow dissipated more

smoothly is helpful to improve the thermal performance of cooling tower. However the excess of flow resistance shoule be

considered carefully. We also find that to evaluate thermal performance of NDCT, airflow rate should be considered first and the

homogeneity of heat tranfer on tower cross section is secondary.

EXPERIMENTAL RESEARCH ON OPTIMIZING INLET AIRFLOW OF INDIRECT DRY COOLING TOWER

UNDER CROSSWIND CONDITIONS

Yan Li, Fengzhong Sun, Yuanbin Zhao, Dongqiang LvShandong University, Jinan, Shandong Province, China

Keywords: dry cooling tower; hot model test; crosswinds; air deflector; thermal performance;

Abstract: To reduce adverse effect of crosswinds on the thermal performance of natural draft dry cooling towers (NDDCT), a

new kind of ventilation optimization technique was put forward, namely air deflector. Inlet airflow uniformity coefficient was

defined to analyze the uniformity of circumferential inlet airflow quantitatively. Based on the hot model test, the impact of air

deflector on the air flow and thermal performance of NDDCT is studied. By contrast between inlet air flow rate and cooling

efficiency, it has been found that crosswinds not only decrease the inlet air flow rate, but also reduce the uniformity of inlet

airflow. After installing air deflectors, the inlet airflow uniformity coefficient and the inlet air flow rate increases, so the cooling

performance of NDDCT was also improved.


9/35


8

Session II-B

Wet cooling towers

Chair: Prof Hanno C.R. Reuter

Stellenbosch University, South Africa


10/35


9

EXPERIMENTAL RESEARCH ON INFLUENCE OF FILLING LAYOUT PATTERNS ON PERFORMANCE OF

COOLING TOWER

Ming GAO, Lei ZHANG, Yuanbin ZHAO, Fengzhong SUN

School of Energy Source and Power Engineering, Shandong University, Jinan250061, China

Keywords: Wet cooling tower; Non-uniform layout filling; Thermal performanceAbstract: Experimental research and exploration in lab is performed to investigate the thermal performance of wet cooling tower

under different layout patterns of filling, and five kinds of layout patterns are studied in this paper. Experimental results show that

the thermal performance under non-uniform layout pattern conditions can enhance by approximately 20%-30%, compared with

uniform layout pattern. Additionally, the non-uniform layout pattern is the best plan when ra/rcis about 0.44 and rb/rcis around

0.71 within the test range.

A CFD STUDY ON WATER COLLECTING DEVICES RESISTANCE CHARACTERISTICS OF THE COOLING

TOWER WITH WATER COLLECTING DEVICE

Feng Jing1, An Yuan1, Guan Xin1, Song Kejia1, Song Xiaojun2

1North China Power Engineering CoLtd., Beijing, China, 100120

2China Institute of Resources and Hydropower Research, Beijing, China, 100038

Keywords: water collecting devices (WCD); resistance characteristics; flow around bluff body

Abstract: Compared with common natural draft cooling tower, cooling tower with WCD(water collecting device) has no rain

zone but WCD was added.WCD was the key part of the tower, its structure not only affected the resistance of the tower but also

affected the air velocity distribution of the fill, study on resistance characteristics of WCD made sense for the cooling tower

design. A CFD model was set to study on it in the paper by Fluent, the resistance values of WCD in different depth were given,

the results can be used for the design of cooling tower with WCD.

INVESTIGATION OF HEAT TRANSFER PERFORMANCE AND FRICTION FACTOR OF A DOUBLE PIPE HEAT

EXCHANGER USING NDG BASED NANOFLUIDS

M. GOODARZI1,*, A. MALVANDI2, B. RAHMANIAN3, E. SADEGHINEZHAD1, M. MEHRALI4,M. DAHARI1and M.S. GOODARZI5

1 University of Malaya, 50603 Kuala Lumpur, Malaysia

2Islamic Azad University, Neyshabur, Iran

3Payam Noor University, Jahrom Branch, Jahrom, Iran

4 University of Malaya, 50603 Kuala Lumpur, Malaysia

5Young Researchers and Elite Club, Mashhad Branch, Islamic Azad University, Mashhad, Iran

Keywords:Nitrogen-doped graphene, Double pipe heat exchanger, and Pressure Drop.

Abstract:Nitrogen-doped graphene (NDG) nanofluids are prepared using a two-step method in an aqueous solution of 0.025wt.%

Triton X-100 as a surfactant with various nanoparticles at several concentrations. The results are reported of experiments on

thermal conductivity, specific heat capacity, viscosity and the convective heat transfer behavior of the NDG nanofluids flowing in

a double pipe heat exchanger. Simulations were performed for Reynolds number equal to 10000 for hot fluid and ranging from

2500 to 10000 for nanofluid as well as nanoparticle weight percentages of 0.00% to 0.06%. The two-dimensional governing

equations were discretized with the finite volume method. The results indicate that the Reynolds number and NDG volume

fraction considerably affect the heat transfer coefficient and consequently the Nusselt number (Nu); a rise in local heat transfercoefficient was noted when both Reynolds number and NDG volume fraction were increased for all cases.


11/35


10

NUMERICAL STUDY ON THE PERFORMANCE OF A NATURAL DRAFT COOLING TOWER WITH COOLED

COLLECTORS

Zhao Shunan1, Guo Fumin2, Feng Jing1, Song Xiaojun1ZHANG Dongwen3

1China Institute of Resources and Hydropower Research, Beijing, China

2Shandong Design Institute of Electrical Power, Jinan, China

3

State Nuclear Electric Power Planning Design and Research I Institute, Beijing, China

Keywords: Cooled collectors, Discrete Phase Model, Heat and Mass transfer Model, resistance coefficient

AbstractCooling tower with cooled collectors can save the pumps head is of advantages in using of large capacity nuclear unite.

This paper focuses on tower performance by CFD, with establishing thermal and aerodynamic characteristics of three dimensional

numerical model about the tower. The numerical simulation results show that: (1) Although the cooled -collectors adds flow

resistance, but this increment is significantly less than the decrease of resistance of rain zone. (2) The ventilation quantity of the

tower with cooled collectors is larger than that of conventional tower in the same situation.(3) The cooling efficiency of the tower

with cooled collectors is superior to the conventional tower.


12/35


11

Session III-ATower structural design & maintenance

Chair: Dr Jessica Shi

EPRI, USA


13/35


12

DESIGN, CONSTRUCTION AND EARLY TESTING OF A 1-MW NATURAL DRAFT DRY COOLING TOWER

Hugh RUSSELL, KamelHOOMAN, ZhiqiangGUAN

University of Queensland, Brisbane, Australia

Keywords: natural draft dry cooling tower, test facility, instrumentation.

Abstract: The QGECE has recently completed construction of a 1 MWt Natural Draft Dry Cooling Tower (NDDCT) Test Facility.The facility has been constructed with funding provided by the QLD State Govt. through the Hybrid Cooling Towers grant, and

aims to test the viability of short NDDCTs in real-life environmental conditions. The tower is 20 m high overall, with a heat

exchanger deck 12 m in diameter. The heat exchanger deck is located at a height of 5 m, giving sufficient distance for spray

cooling evaporation beneath the heat exchangers. The shell of the tower is a PVC membrane, supported by a lightweight steel

truss structure that also bears the heat exchanger deck. The tower is fully instrumented for both the water- and air-flow paths; this

will permit a unique perspective of the distribution factors such as temperature, humidity and flow within the tower in both calm

and crosswind conditions, and at varying ambient temperatures.

BEHAVIOUR OF R/C COOLING TOWER SHELL UNDER LATERAL LOAD ON NON-UNIFORM FOUNDATION

Takashi HARA11National Institute of Technology, Tokuyama College, Shunan, Japan

Keywords: cooling tower, wind load, settlement, reinforced concrete, ultimate strength.

Abstract: The stress distributions and the ultimate strength of a reinforced concrete (R/C) cooling tower shell under a self-weight

and a lateral wind load were investigated under the conditions on non-uniform foundation. The construction site of the cooling

tower is quite huge and the site may have different bearing capacities within location by location. Therefore, to design such

structures, the effects of uneven settlements of supporting system due to the non-uniform foundation should be considered. In

modelling the cooling tower, the height of the shell was about 160m and the radius at the lintel was about 60m. From thenumerical analysis, the stress concentration was arisen near the connections between the unsettled column and the lintel and the

ultimate strength was reduced by the uneven settlement depend on the wind direction. The foundation beam plays an important

role to transfer the stresses.

MULTI-OBJECTIVE OPTIMIZATION ANALYSIS OF STRUCTURAL DESIGN FOR LARGE COOLING TOWERS

Lin ZHAO1, Yuwen LIANG1, Xu CHEN1, Yaojun GE1, Wen SUN2, Yinan Li3, Dongwen Zhang3, Jiantao He3, Yingtao Li3,

1State Key Lab for Disaster Reduction in Civil Engineering, Tongji University, Shanghai, China

2 Shandong Electric Power Design Institute, Jinan, China

3State Nuclear Electric Power Planning Design & Research Institute, Beijing, China

Keywords: Cooling tower, Multi-objective Optimization, Structural Design

Abstract: Under the effect of equivalent wind load that acquired by the theory of CQC extreme value response result at the

equivalent target node has the large error. To this problem, it conducts the conclusion to the study process of multi-objective

equivalent static wind load, and summarize the cricials points in the process of its essence and numerical value optimization

process. Combined with the wind vibration characteristics of large cooling towers itself, it puts forward the improved multi-

objectives equvailent wind load computing method. Through the analysis of three kinds of numerical examples of equivalent

working conditions, it further discusses the multi-objective equivalent wind load distribution characteristics, its rationality of

application in the large tower structure, and gives the multi-objective equivalent wind load fitting polynomial at the differentheights circular cross sections.


14/35


13

WIND-INDUCED EFFECTS OF AN LARGE COOLING TOWER SUFFERING THE NORMAL WIND AND

TYPHOON

Xu CHEN1, Lin ZHAO1,Yaojun GE1

1State Key Lab for Disaster Reduction in Civil Engineering, Tongji University, China

Keywords: Cooling tower, Normal Wind, Typhoon, Wind-induced effect, Construction costAbstract: Nowadays, more and more large cooling towers in China have been built in the typhoon-prone regions of coastal. Wind

field parameters between normal winds and typhoons are quite different. The 3D wind load models of normal winds and typhoons

were built based on the mathematical relationship between the dynamic wind loads and turbulence intensities suggested by the onsite

measurement. The self-developed software for the design of large cooling towers were adopted to calculate the wind-induced effects

under the normal winds and typhoons, which were compared with the results under the wind loads suggested by the Chinese load code.

The results show that it is difficult to distinguish the adverse loads adopting the displacement or internal force responses. Therefore, a

method considering the buckling coefficient and construction cost to evaluate wind-induced effects were proposed.

METHODS OF INSPECTION AND MAINTENANCE OF ITERSON COOLING TOWERS

Ji BYDOVSK1, Rostislav DROCHYTKA2and VtERN3

1,2,3Brno University of Technology, Faculty of Civil Engineering, Brno, Czech Republic

Keywords: Cooling tower; durability; repair mortar; surface treatment

Abstract: Iterson cooling towers make essential part of power station technology. Although cooling towers may appear at first

sight that they have similar life span as dams and other monumental constructions, but in reality it is not so. The tower shell is

formed by thin-walled reinforced concrete construction, with life span approximately 40 years, but due to negative degradation

effects their life span can be shorter. In order to improve life span of the cooling towers for entire power station service-life, their

regular inspection and maintenance is required. This paper deals with basic principles of inspection and maintenance methods,completed with pictures of inspections and repair works.

A STUDY ON THE DEPTH AND PITCH FACTOR CORRELATIONS AND SHAPE OPTIMIZATION OF CHEVRON-

TYPE PLATE HEAT EXCHANGERS

Byeong-Ryeon Kim1, Oh-Kyung Kwon2, Dong-An Cha2, Kyung-Jin Bae2, Min-su Kim3Chan-Woo Park3

1Department of Mechanical Design, Chonbuk National University, Korea

2Energy System R&D Group, Korea Institute of Industrial Technology

3Department of Mechanical Design, Chonbuk National University, Korea

Keywords: Plate heat exchanger (PHE), absorption chiller, pressure drop, chevron, Wilson plot method, overall heat transfer

coefficient, heat recovery, condensation

Abstract: The performance of a plate heat exchanger for liquid solution absorption chiller was analyzed. The objectives of this

paper are to measure the heat transfer and pressure drop through the plate heat exchanger for absorption system applications. Three

types of plate heat exchangers with different chevron angles are tested in the present experiment. The working fluid is H 2O/LiBr

solution with LiBr mass concentration of 55%. The results show that the overall heat transfer coefficient increases linearly with the

increase of Re. This work is a basic study of a cycle in which LiBr aqueous solution, which has been diluted through the absorption

of water vapor in the absorber of an absorption chiller, is made concentrated before reaching the regenerator.


15/35


Session III-B

Wet cooling towers

Chairs: Prof Fengzhong Sun

Shandong University

Prof Wuquan Li

Electric Power Planning & Engineering Institute


16/35


15

COMPARISON BETWEEN 1D AND 2D CALCULATION METHODS FOR SUPER LARGE COOLING TOWER

WITH WATER COLLECTING DEVICES

Zhang Dongwen, Luan Wei

State Nuclear Electric Power Planning Design and Research Institute, Beijing China

Keywords: the cooling tower with water collecting devices, the conventional, 1D and 2D thermal calculation, wind and waterdistribution

Abstract: Thermal performance and wind field distribution in the conventional and that with water collecting devices are studied

using 1D and 2D numerical simulation methods. With the absence of rain zone, the cooling towers with water collecting devices

have well-distributed wind velocity in its filling section, so the uniform arrangement of filling is recommended, and 1D method

can meet the requirements of engineering design. On the contrary, with non-uniform wind distribution, different height

arrangement of filling should be used in the conventional, besides, optimizing the wind and water distribution by 2D method.

EXPERIMENTAL STUDY ON THE FLOW FIELD OF THE WATER COLLECTING DEVICES

Dongqiang LV, Fengzhong SUN, Yuanbin ZHAO, Yan LI

School of Energy and Power Engineering, Shandong University, Jinan 250061, China

Keywords: water collecting device; cooling tower; wind tunnel experiment; flow field

Abstract: The wind tunnel experiment is employed in this paper on different structure of the water collecting devices trial models,

with a view to investigate principally the static pressure drop and the velocities of the airflow inside the trial models. Preliminary

study of numerical simulation is conducted, a three dimensional (3D) computational model is developed with the guidance of the

experiment to explore the 3D flow field in the water collecting devices based on a Reynolds time-averaged k-epsilon two-equation

model. Studies in the paper point to the fact that numerical simulation results match the experiment measurements very well,

which is to say numerical analysis to the water collecting devices is feasible. These conclusions lay an experimental foundationfor further research on the numerical simulation to the flow field of the water collecting devices.

TECHNICAL RESEARCH AND ECONOMIC ANALYSIS FOR COOLING TOWER WITH WATER COLLECTING

DEVICE OF 1000MW COAL-FIRED POWER PLANT

Yuan AN1, Jing FENG1, LUJUN LI2

1North China Power Engineering CoLtd., Beijing, China, 100120

2China Institute of Resources and Hydropower Research, Beijing, China, 100038

Keywords: Water Collecting Device (WCD); High-level collecting water; Energy saving; Coal-fired power plant

Abstract: Cooling water tower with WCD is gradually recognized in the 1000MW coal-fired power plant, this paper introduces

process arrangement, technical characteristics and design optimization of collecting water cooling tower. Through design data and

experimental study of 1000MW coal-fired power plant to analyze technology economic and comprehensive benefits of collecting

water cooling tower. The results show that Cooling water tower with WCD has the advantage of low noise, saving energy, and

low operation maintenance cost.

HEAT TRANSFER DURING CAVITATION BUBBLE COLLAPSEZongyi QIN1and Habib ALEHOSSEIN2

1The Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia


17/35


16

2School of Civil Engineering and Surveying, University of Southern Queensland, Australia.

Keywords: Heat transfer, Cavitation, Conduction, Radiation, CFD, Bubble simulation.

Abstract: Cavitation is the formation of bubbles in a liquid with various industrial applications such as high-pressure cavitation

water jets used in rock drilling, wastes treatment, biomedical and heating systems. The collapse process of a cavitation bubble can

become extremely violent generating substantial heat. To accurately calculate the temperature change and heat transfer during

bubble collapse, a heat transfer model including conduction and radiation is introduced. A two-phase compressible CFD modeldeveloped to simulate the bubble collapse process and demonstrate variations of the pressure, temperature and velocity

distribution in the bubble and surrounding liquid. Our previous Rayleigh-Plesset (RP) solution has been modified to incorporate

heat conduction and radiation effects. The results of the CFD modelling match the RP solutions very well. Heat transfer of

bubbles of various size is considered in the new RP solution. A cavitation bubble can accumulate heat energy per cycle of 40 J

while generating heat with temperatures up to 0.02MK.

DESIGN OF ON-LINE MONITORING SYSTEM ON DRIVE MECHANISM OF COOLING TOWER DRAUGHT FAN

Yang Fang1, Zhao Yan2, Li Jishun1, Xue Yujun1, Liu Chunyang1

1Henan University of Science and Technology, Henan Key Laboratory for Machinery Design and Transmission System, Luo Yang, Henan 471003, P.R. China

2Luoyang Bearing Science & Technology Co., Ltd., Luo Yang, Henan 471039, P.R. China

Keywords: Condition monitoring, Data acquisition, Network communication, ADSP.

Abstract: The drive mechanism vibration of draught fan is a potential security issue during the long term operation. In order to

monitor the fault of draught fan, a kind of on-line monitoring system for drive mechanism of cooling tower draught fan was

developed. In this work, an on-line monitoring system based on ADSP-BF518 processor was designed, which could cope with

diversified status parameters of drive mechanism. The key techniques for acquiring multivariate signals and data-processing, such

as CPLD-based function expansion, ADC, DAC, synchronization logic and network interface, were presented in details. The on-

line monitoring system can realize real-time monitoring of multiple transmission mechanism by means of the networkcommunication. Using PC monitoring software, the status signal can be processed and the characteristic value of signal can be

extracted, by which the status evaluation of drive mechanism can be carried out. The developed on-line monitoring system is

capable of condition monitoring for drive mechanism of cooling tower draught fan by gathering data and analyzing the status

message of drive mechanism in real time. The research results could ensure that the cooling tower fan operation works in safe

condition.

COOLING PERFORMANCE STUDY ON NATURAL DRAFT WET COOLING TOWER WITH HIGH LEVEL

WATER COLLECTING

Guoqing LONGa, Yuanbin ZHAOb, Fengzhong SUNb, Yanyan Wub, Dongqiang LUb

aGuangdong Electricity Power Design Institute, Guangzhou 510660, China

bSchool of Energy and Power Engineering, Shandong University, Jinan 250061, China

Keywords: Wet cooling tower; water collecting devices; numerical simulation

Abstract: With the advantages of less air pressure drop in air inlet, reducing pumping power and decreasing acoustic pressure,

natural draft wet cooling towers with high level water collecting devices (HNDWCT) are now popularized along with the

development of large capacity power units. The high level water collecting devices, being installed below fill, can recover some

gravitational potential of falling water, which is fully lost in the rain zone below fill in the usual natural draft wet cooling tower

(UNDWCT). To study the cooling performance characteristics of HNDWCT, a three-dimensional (3D) numerical computationmodel for HNDWCT was established, with full consideration of the structure of high level water collecting devices. The


18/35


17

aerodynamic field around tower, especially that near the water collecting devices was elaborated so as to clarify the impact of

water collecting devices on the cooling performance of natural draft wet cooling tower.

Session IV-A

Dry & Wet cooling towers

Chair: Roger Rush

Industrial Water Cooling (IWC), South Africa


19/35


18

DESIGN OF A NATURAL DRAFT DRY COOLING TOWER FOR A 30-MWE CONCENTRATING SOLAR

THERMAL PLANT USING A SUPERCRITICAL CO2 CYCLE

Jishun Li*1, Tianyi Song2, Xiaoxiao Li3, Hal Gurgenci3and Zhiqiang Guan3

1Henan University of Science and Technology, China

2Luoyang Longhua Heat & Energy Conservation Co., LTD., China

3

University of Queensland, Australia

Key words: Natural draft cooling tower, Supercritical CO2, Solar thermal

Abstract: Supercritical CO2 (sCO2) operated in a closed-loop recompression Brayton cycle offers the potential of higher cycle

efficiency versus supercritical or superheated steam cycles at temperatures relevant for CST applications. A set of sCO2turbines

and compressors is about 3-4% the size of a conventional steam generator of similar power rating. It is believed that concentrating

solar thermal (CST) power plants using sCO2cycle could reduce the power block size and potential saving. This paper presents

the design of a natural draft dry cooling tower for a proposed 30-MWe CST plant proposed in Luoyang, China.

ANNUAL PERFORMANCE VARIATION OF AN EGS POWER PLANT USING AN ORC WITH NDDCT COOLING

Sam DUNIAM, Hal GURGENCI

The University of Queensland, Brisbane, Australia

Keywords: Geothermal, Natural Draft Dry Cooling Tower, Organic Rankine Cycle.

Abstract: The purpose of this paper is to assess the influence of the variation of performance of a Natural Draft Dry Cooling

Tower (NDDCT) due to changing ambient temperature, and the effect this has on an Enhanced Geothermal System (EGS) power

plant using an Organic Rankine Cycle (ORC). A one dimensional cooling tower model was developed and integrated into a cycle

model. The ORC considered is the supercritical butane organic Rankine cycle, with three cycle variations considered; the basic,

recuperated and regenerative cycles. The EGS heat source conditions used are those found at the Habanero 1MW pilot plant inSouth Australia, with geothermal brine inlet temperature of 220oC, minimum brine temperature of 80oC, and brine mass flow rate

of 35kg/s. The analysis finds that diurnal variation of net power generation is typically of the order of 10%, but in the most

extreme case may be as much as 30%.

RESEARCH ON APPLYING DRY COOLING TECHNOLOGY IN CONVENTIONAL ISLAND OF AP1000 NUCLEAR

POWER IN CHINA

Chai Jingyu1,Li Wuquan2Zheng Jingwei3

1,2,3Electric Power Planning & Engineering Institute, Beijing, China

Keywords: Indirect dry cooling system; Lack of water region; Conventional island; Application.

Abstract: In inland nuclear power plant adopted re-recycle water cooling system in conventional islandthe water consuming is

approximately double of the thermal power plant with the same capacity. When dry cooling technology is adopted, the water

consuming is same with the coastal nuclear power plant, and the fuel do not increase which is always happed in the thermal power

plant cause of the backpressure. The research of the applying dry cooling technology in inland nuclear power plant is urgent with

good prospects. This paper focuses on the construction of AP1000 nuclear power in water lacking district inland, analyses the

using of indirect dry cooling system, proposes some suggestions for the engineering practice.


20/35


19

EFFECT OF CROSS WIND ON THE PERFORMANCE OF A NATURAL DRAUFT COUNTER FLOW COOLING

TOWER OUTLET

Shun-An Zhao1, Ming-Ren Wang2, Lu-Jun Li1, Cheng-Qi Du2

1China Institute of Water Resources and Hydropower Research, Beijing, China

2East China Design Institute of Electrical Power, Shanghai, China

Keywords: cross wind; cooling tower; air inlet; pressure loss coefficient.Abstract: Cooling efficiency of counter-flow natural draft cooling tower can be reduced by cross wind, so it is necessary to

consider cross wind impact to revise the design. In the paper, a 3d numerical simulation method is used to research effect of cross

wind on pressure loss coefficient of the air outlet of counter-flow natural draft cooling tower. The results show that an additional

resistance would be exist on air flow of the tower while wind velocity is not more than twice of the mean outlet velocity of the

tower, otherwise an additional draft would be formed.

CFD ANALISYS OF DRIFT ELIMINATORS USING RANS AND LES TURBULENT MODELS

J. RUIZ1, A.S. KAISER3, B. ZAMORA3, C.G. CUTILLAS2and M. LUCAS2

1Dept. of Mechanical and Energy Engineering, Universidad Miguel Hernndez, Elche, Spain

2Universidad Miguel Hernndez, Spain

3Universidad Politcnica de Cartagena, Spain

Keywords: Cooling tower, drift, drift eliminator, CFD, RANS, LES.

Abstract: Drift eliminators design should guarantee high collection efficiencies, for preventing cooling tower emissions, and low

induced pressure losses, in order to reduce the energy consumption of the cooling system. CFD methods have become a

straightforward strategy to achieve a deeper knowledge of the internal flow in the eliminator, which may result on a better design

of it. In this work 3 lath-type drift eliminators are numerically investigated. For this purpose Reynolds Average Navier--Stokes

(RANS) and Large Eddy Simulation (LES) turbulence models are considered, since the interaction of the water droplets with theturbulent scales may be relevant in order to predict accurately the collection efficiency of the eliminator. The effects of

considering the turbulence dispersion of droplets in the RANS models are also studied. The LES model is able to accurately

predict the flow configuration, the detachment of the boundary layer and to solve the scales of motion (eddies) more dependent of

the studied geometry. The RANS models have proven to appropriately predict the performance of the eliminator (pressure drop

and collection efficiency). The differences between LES and RANS in pressure drop and collection efficiency prediction are less

than 3%. For the eliminator design task, the RANS approach enhanced with the turbulent dispersion of droplets is sufficient to

predict the eliminator performance. In this sense the numerical efforts must be focused on the appropriate modelling of the water

film formed on the eliminator's wall since the numerical model has failed to predict the experimental results.


21/35


20

Session IV-B

Heat exchangers

Chair: Takashi HARA

National Institute of Technology

Tokuyama College, Japan


22/35


21

PERFORMANCE EVALUATION OF WATER COLLECTION SYSTEMS WITH A HYBRID DEPHLEGMATOR

Jacques du Plessis1and Prof. H.C.R. Reuter2

1Department of Mechanical Engineering, Stellenbosch University, South Africa

Keywords: Water collection, Troughs, Basin, Counter flow, Inlet loss coefficient.

Abstract: Water collection systems are used in wet-cooling towers (WCTs) and in evaporative air-cooled heat exchangers(EACHEs). Collection systems collect and remove water falling while allowing air to pass with limited flow resistance. Collection

systems can be categorized as trough and basin systems. Trough systems comprise of multiple, evenly spaced parallel troughs

extended in one direction. With basin systems water falls directly into an open basin under gravity where it is collected. A more

effective water collection system with a lower pressure drop than what current designs have to offer is developed for (dry/wet)

dephlegmator (HDWD) for air-cooled steam condensers, developed at Stellenbosch University. An existing trough design is

evaluated by means of high speed camera and flow experiments. A modification is proposed which increases the effectiveness

from approximately 92% to 100 % with a relatively small increase in pressure drop, by adding a small deflector plate and reducing

the spacing between adjacent troughs.

THERMAL AND HYDRAULIC PERFORMANCE OF A HEAT EXCHANGER OPERATED WITH ICE SLURRY AS

REFRIGERANT

Amin KAMYAR, Saiied M. AMINOSSADATI, Christopher R. LEONARDI

The University of Queensland, QLD 4072, Australia

Keywords: Ice slurry, Heat Transfer, Laminar flow, Helical coil

Abstract: Ice slurry has been potential candidates due to its high heat transfer capability as a phase change material. Previous

research show that ice slurry flows contribute to reductions in the amount of charge of primary refrigerant and enables load

shifting which results in substantial operating cost savings. In this study, a numerical analysis of a heat exchanger performanceoperated with ice slurry is presented. The role of various parameters including ice concentration and mass flow rate on the heat

transfer and pumping power is presented and results are compared with those for the carrier fluid at the same conditions. The

results show that ice slurry and geometry of the heat exchanger enhance the heat transfer performance. A significant increase in

the pressure drop is also observed for the ice slurry flowing through this type of heat exchanger.

INVESTIGATION OF THE SPLITTING OF LOUVERS FOR A LOUVERED FIN AND TUBE HEAT EXCHANGER

Bernd AMEEL1,JorisDEGROOTE1, HenkHUISSEUNE1, Jan VIERENDEELS1and Michel DE PAEPE1

1Ghent University - UGent, Ghent, Belgium

Keywords: CFD, louvered fin, heat exchanger

Abstract: Many different authors have studied the louvered fin geometry, in order to improve the performance of the louvered fin

and tube heat exchanger, which is often used in air conditioning applications. In numerical studies, simplifications are often made

to the geometry. Some authors take the connection between the louvers and the fin around the tube into account (the flat landing),

whereas other authors do not. Some authors assume a rectangular shape for the louvers, whereas other authors use an X-shape. For

an X-shaped louvered fin, the louver length increases further away from the turnaround louver. In reality, the louvers furthest

away from the turnaround louver tend to be split into two parts. This geometrical detail has always been neglected in the available

studies. However, the transition zones between the flat part and the louvers around the split are positioned at an angle to the local

flow, which could generate vortices. Furthermore, by splitting the louver into two, the length of both individual louvers isdecreased, which could result in an increase in fin efficiency. In this study, different splitting strategies for the X-shaped louvered

fin are investigated using computation fluid dynamics (CFD) simulations. It is revealed that for low Reynolds numbers, the effect


23/35


24/35


23

Session V-A

Cooling system optimization

Chair: Prof Yaojun Ge

Tongji University, China

Prof Jishun Li

Henan University of Science and Technology, China


25/35


24

WATER CONSUMPTION COMPARISON BETWEEN A NATURAL DRAFT WET COOLING TOWER AND A

NATURAL DRAFT HYBRID COOLING TOWER AN ANNUAL SIMULATION FOR LUOYANG CONDITIONS

Jishun Li, Xia Lin, Wei Ma, Hal Gurgenci and Zhiqiang Guan

School of Mechatronics Engineering, Henan University of Science and Technology, Luoyang, China

Keywords: Merkel method, Poppe approach, wet cooling tower, hybrid cooling tower.Abstract: In a natural draft wet cooling tower (NDWCT), the heat is mainly transferred by latent heat through water evaporation.

This causes large quantities of water evaporate into the moving air stream and discharged to the atmosphere on top of the tower.

Thus, the utilization of natural draft hybrid cooling tower (NDHCT) in thermal power plant would conserve water and would be in

the best interest of the public. The Merkel method, Poppe approach and the empirical equation are employed in this paper to

predict the evaporation loss for a 300MW NDWCT in Luoyang, China. The results show that the Poppe approach is the most

accurate prediction for water loss in NDWCT. The annual simulation results for the thermal power plant show that more than 90%

fresh water could be saved, if the NDHCT is employed to replace the NDWCT.

ENGINEERING SOLUTIONS FOR COUNTER-FLOW COOLING TOWERS DESIGNED FOR COLD CLIMATIC

ZONES

Boris SVERDLIN, Dmitrii ELISEEV

EKOTEP Ltd., Saint-Petersburg, Russian Federation

Keywords: cooling tower icing

Abstract: this report is dedicated to the description and analysis of engineering solutions applied on the cooling towers

maintained in the regions with cold climate and high risk of icing.

COMPARISON OF A BASIC ORGANIC RANKINE CYCLE AND A PARALLEL DOUBLE-EVAPORATOR

ORGANIC RANKINE CYCLEDongshuai Hu, Yi Wu, Yike Gao, Yue Cao, Yiping Dai

Institute of Turbomachinery, Xian Jiaotong University, Xian, China

Keywords: Multi-evaporator organic Rankine cycle, Zeotropic mixture, thermo-economy.

Abstract: The applications of zeotropic mixtures and multi-evaporator systems are two viable options to improve the performance

of organic Rankine cycle (ORC). This paper conducts the thermo-economic comparison of a basic ORC with R245fa/R600a and a

parallel double-evaporator organic Rankine cycle (PDORC) with R245fa. Sub-models of condensers and evaporators are

established specially for pure organic fluids and zeotropic mixtures. Both the net power and the total heat exchanger area are

considered as evaluation criterions. The performance optimization using genetic algorithm is conducted to compare the two

systems quantitatively. The optimization indicates the PDORC with R245fa shows an increase of 18.1% on the net power and an

increase of 69.4% on the total heat transfer area from the basic ORC.

CONTACT OF DROPLETS WITH HEAT EXCHANGER SURFACES IN SPRAY ASSISTED DRY COOLING

TOWERS USING SALINE WATER A NUMERICAL STUDY

M.H. Sadafi, Ingo Jahn, Kamel Hooman

School of Mechanical and Mining Engineering, The University of Queensland, QLD 4072, Australia

Keywords: saline water; hybrid cooling; discrete phase model; multicomponent; heat and mass transfer; corrosionAbstract: This article investigates the usage of saline water in a spray assisted natural draft dry cooling tower. Due to existence of

solid particles in the spray, different scenarios of droplet/heat exchanger contact occur. The different cases including the contact of


26/35


25

the heat exchangers with the wet droplets, semi-dried droplet, and fully dried solid particles are numerically investigated. To

simulate the crystallisation behaviour of saline water droplets, a set of modifications are made to the multicomponent discrete

phase model (DPM) of ANSYS FLUENT. A practical spraying application with a single nozzle in a vertical flow path is studied.

This paper provides new fundamental understanding in the area of saline spray cooling, and shows that although the use of saline

water increases the risk of corrosion and deposition on the surfaces, considering the necessary parameters in the design can control

these effects.

COMPARISON OF DIRECT AND INDIRECT COOLING IN AN sCO2 BRAYTON CYCLE FOR CONCENTRATED

SOLAR POWER PLANTS

Erond PEREZ, Sam DUNIAM, Yuanshen LU, Ingo JAHN, Kamel HOOMAN, and Anand VEERARAGAVAN


Keywords: concentrated solar power, natural draft dry cooling tower, direct and indirect cooling

Abstract: The supercritical carbon dioxide (sCO2) Brayton cycle has been identified as a promising candidate for the power cycle

in Concentrated Solar Power (CSP). It exhibits high efficiency even with dry cooling, has smaller components and less complex

cycle design. In this paper, cooling of the sCO2 cycle is investigated by the use of Natural Draft Dry Cooling Towers (NDDCTs).

Two configurations are considered; direct and indirect cooling. Direct cooling is where ambient air is used to cool the sCO2 that is

sent to the NDDCT while in indirect cooling, sCO2 rejects heat through a secondary water loop through an intermediate heat

exchanger (IHX) and the water is cooled by ambient air in the NDDCT. Direct cooling is investigated as a means to reduce exergy

losses to the additional heat transfer process in the IHX for indirect cooling. For each case, size of the NDDCT are similar and

their effect on cycle performance are discussed.

PARAMETRIC STUDY ON SPRAY COOLING SYSTEMS IN NATURAL DRAFT DRY COOLING TOWERS WITH ANEW NOZZLE REPRESENTATION APPROACH

Abdullah Alkhedhairc, Zhiqiang Guan, Ingo Jahn, Hal Gurgenci

Queensland Geothermal Energy Centre of Excellence, School of Mechanical and Mining Engineering, The University of Queensland, Brisbane, Australia, 4072

Keywords: spray cooling, air pre-cooling, natural draft, nozzle optimisation, spray representation

Abstract: Pre-cooling of inlet air with water spray is proposed for performance enhancement of natural draft dry cooling towers

(NDDCTs) during high ambient temperature periods. In this study, an Eulerian-Lagrangian 3-D numerical model was used and

validated to simulate evaporating water sprays produced by real nozzles. A new adaptable method of hollow-cone spray

representation into an Eulerian-Lagrangian numerical modeling was developed to reproduce the real nozzle behavior using

experimentally measured initial spray characteristics and taking into account radial evolution of droplet size distribution and

air/droplets momentum exchange. A parametric analysis using the validated CFD model with the new nozzle representation

method was conducted on the effect of different spray characteristics parameters on spray cooling system performance for nozzle

design optimisation.


27/35


26

Session V-B

Heat exchangers

Chair: Dr Manuel Lucas

Universidad Miguel Hernandez, Spain


28/35


27

SIMULATION OF HEAT TRANSFER FROM A CONVEX HOT SURFACE USING AN IMPINGING JET

Pourya FOROOGHI1, Mingfei LI2and Franco MAGAGNATO1

1Institute of Fluid Mechanics (ISTM), Karlsruhe Institute of Technology, Germany

2Department of Thermal Engineering, Tsinghua University, Peoples Republic of China

Keywords: Surface cooling; Impinging jet; RANS.Abstract: Impinging jets are efficient means of cooling in various industrial applications. In this paper, flow and heat transfer due

to a cold gaseous jet impinging on a hot convex surface is numerically investigated. The temperature difference between the jet

and the surface reaches up to 580K and the nozzle-to-surface distance is equal to the nozzle diameter. Due to the small nozzle-to-

surface distance, flow and heat transfer over the impinging surface are highly sensitive to the nozzle flow conditions; therefore, in

this study various inlet conditions are examined and compared. Compressible Navier-Stokes equations are solved using in-house

code SPARC, and the results are compared to experimental data obtained from a similar geometry.

ENHANCING TURBINE OUTPUT AT DRY-COOLED POWER PLANTS USING A HYBRID (DRY/WET)

DEPHLEGMATOR

Michael OWEN1, Detlev KRGER2and Hanno REUTER2

1Solar Thermal Energy Research Group, University of Stellenbosch, South Africa

2Department of Mechanical and Mechatronic Engineering, University of Stellenbosch, South Africa

Keywords: Air-cooled steam condenser, hybrid (dry/wet) dephlegmator, turbine output.

Abstract: This paper examines the benefits to steam turbine output of retrofitting an air-cooled steam condenser (ACC) with a

hybrid (dry/wet) dephlegmator (HDWD) in coal-fired, reheat, regeneration cycle. A HDWD concept has been proposed and

shown to provide enhanced ACC cooling performance while consuming only a small amount of water. The HDWD retrofit is

shown to be able to increase turbine power output by up to 10.8 % in this case. A corresponding increase in annual energy outputof 2.56 % can be achieved for continuous wet operation of the HDWD. A likely operating scenario, where HDWD units are

sequentially operated in wet mode in order to maintain rated turbine power output over a wide range of ambient temperatures,

results in an annual energy output increase of 1.33 %. Based on these results the payback period for an HDWD retrofit is between

3 and 6 years. The HDWD concept offers a simple, cost effective and sustainable solution to the issue of reduced ACC

performance at high ambient temperatures.

ANALYSIS ON THE COLLIMATED IRRADIATION IN A SOLAR AIR RECEIVER WITH POROUS MEDIA

P. Wanga, D.Y. Liu b, C. Xua, L. Zhou b, L. Xia b

a.Department of Renewable Energy Science and Engineering, Hohai University, Nanjing, China;

b.Department of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, China

Keywords: Porous media, Local thermal non-equilibrium, Convective heat transfer, Collimated irradiation, Modified differential

approximation (P-1)

Abstract: Convective and radiative transport in a air receiver with porous media in the presence of collimated irradiation and

local thermal non-equilibrium is analyzed in this work. A modified P-1 approximation with collimated irradiation was introduced

to incorporate the radiative transfer. We analyzed the distribution of the temperature of the fluid and solid phase, also the heat flux

in the incident direction was presented. The temperature Ts along the X direction is decrease for the solid phase but increases for

the fluid phase temperature f along the X direction. The limiting interactions between thermal radiation and conduction wasrevealed. The porosity and pore diameter has a non-monotonic effect on the thermal efficiency of the receiver, optimization can be

achieved by further parameters analysis.


29/35


28

NUMERICAL ANALYSIS ON EQUIVALENT STIFFNESS OF METAL BELLOWS EXPANSION JOINT IN WATER

CIRCULATION PIPING LINES

Li Jishun1, Fang Jingwen, Ma Wei, Yang Fang, Xue Yujun

Henan University of Science and TechnologyHenan Key Laboratory for Machinery Design and Transmission SystemLuo YangHenanP.R. China

Keywords: Metal bellows expansion joint, Equivalent stiffness, Finite element method.

Abstract: In this paper, a numerical model of metal bellows expansion joint was established by using finite element method to

analyze the relationship between the equivalent stiffness and structural parameters of metal bellows expansion joint. In order to

verify the numerical model, the numerical simulation result was compared with EJMA (The Expansion Joint Manufacturers

Association, INC.) formula calculation result as well as tests result. Based on the numerical model, effects of structural parameters

including height of wave, number of wave, distance of wave, diameter, and wall thickness, on the equivalent stiffness of metal

bellows expansion joint were investigated. The research results show that the equivalent stiffness of metal bellows expansion joint

is increased with the increase of distance of wave, diameter, and wall thickness; however, the equivalent stiffness of metal bellows

expansion joint is decreased with the increase of height of wave and number of wave. Using proposed numerical analysis method,

the relationship between the equivalent stiffness and structural parameters of metal bellows expansion joint could be obtained. The

present studies would be helpful for designing the appropriate metal bellows expansion joint to satisfy the compensation

requirements for water circulation piping lines.

OPTIMALIZING GEOTHERMAL WATER DOMINATED SYSTEM PRODUCTION WITH VIBRATION TO

ABDICATE FLUID SURFACE TENSION

Agung Satria Warman1 and Rihan Efendi

State University of Padang, Padang, Indonesia

Keywords: Geothermal Water Dominated, Vibration, Surface Tension

Abstract: Mostly, geothermal water dominated system is found in Indonesia because geothermal in Indonesia is formed by highterrain system. Geothermal production is very influenced by fluid motion (steam and water) caused by geothermal gradient from

temperature difference. Sometimes fliud motion is blocked by surface tension among steam, water, and permeability medium. In

this case, geothermal production decrease because this surface tension problem. This paper will give solution with vibration wave

to move the surface tension contact. Therefore, surface tension will pass away because disturbed by vibration which move surface

tension contact. This paper will study about minimum energy of vibration wave for disturbed surface tension to increase

geothermal production. This minimum energy useful to estimate effective cost for increase production with vibration wave and

bounding vibration energy for decrease environment effect cause vibration wave. From this estimate, we can determine

instrumentation to generate the vibration energy.

GEOTHERMAL POTENTIAL FOR ALUMINA PRODUCTION IN WEST KALIMANTAN

Agung Satria Warman1 and Rihan Efendi

State University of Padang, Padang, Indonesia

Keywords: Alumina Smelter, geothermal potential, Enhanced (orengineered) Geothermal Systems, West Kalimantan.

Abstract: Indonesia is the largest producer of bauxite in the world. In 2011, 40 million tonnes of bauxite were exported to China

and Japan. But it is still a raw material which has a lower value than the final product i.e. aluminium metal.Bauxite must be

treated by the Bayer Process to get alumina and then alumina is changed to aluminium by the Hall-Heroult Process. A lack of

capital is one reason for government not to build an alumina smelter and also the energy consumed by an alumina smelter can bemajor problem. In some cases the lack of power supply near a bauxite mining area can besolved. For example in West Kalimantan,

the power supplies problem could be solved by building a PLTP(Pembangkit Listrik Tenaga PanasBumi).This solution is


30/35


29

attractive because operating costs would be cheaper in West Kalimantan, which is the largest producer of bauxite in region, after

Bintan Islands. Thus alumina could be produced efficiently because the PLTP and the bauxite mine would be in the same

area.Investigations carried out by PT Alcoa Mineral Indonesia found 800 x 106 tonnes ofbauxite reserves in West Kalimantan in

1974. The geothermal energy potential is high eventhough it is not yet used to produce a large amount of power in West

Kalimantan.In 2006 the Department of Mining and Energy in found five locations with geothermal energy potential in West

Kalimantan and so far they have been used to produce about12.5 MW of electric power.

Session VIHeat exchangers

Chair: Prof Hal Gurgenci



31/35


30

A STUDY ON COOLING PERFORMANCE OF AIR-COOLED HEAT EXCHANGERS FOR CSG PRODUCTION

Yuanshen Lu1,2, Prashant Parulekar3, Zhiqiang Guan1,2, Kamel Hooman1,2

1Queensland Geothermal Energy Centre of Excellence, Qld 4072, Australia

2School of Mechanical and Mining Engineering, the University of Queensland, Qld 4072, Australia

3Arrow Energy, Brisbane QLD 4000, Australia

Keywords: Finned tube heat exchangers, mechanical cooler, multi-section heat exchangers, CSG compression cooling

Abstract: This paper reports a study on a real cooling issue in the heat exchangers used in Queenslands coal seam gas (CSG)

industry. CSG gas compression facilities in some production sites suffer underproductions in recent summers because of frequent

automatic engine shutdowns. The cause of the issue was suspected that the control systems on the compression facilities trigger

the overheating-protection shutdowns due to the possible deficiencies in one or some water/gas cooling loops in the facilities air-

cooled heat exchangers. However, it is unknown which heat exchangers or what exact reasons cause the unexpected cooling issue

which is not expected by the manufacturers design. Therefore, an investigation has been carried out on the cooling performance

of the cooler units in the gas compression facilities. A field instrumentation measurement on one operating cooler unit has been

done, followed by an analysis using a 1-dimensional analytical model. The experimental results are used to validate the 1D model.

Then the cooling performance of the cooler unit under the summer peak condition is predicted by the verified analytical model.

The prediction suggests that the water inlet temperature in engine water cooler section is higher than its upper limit defined by the

manufacturer due to poor cooling at high ambient temperatures. The lower cooling performance is caused by large reductions in

the cooler air speed and total heat transfer coefficient. The former is a direct result of the less efficiency of cooler fans, while the

latter is related to fouling on the finned-tube surfaces.

DESIGN SENSITIVITY ANALYSIS OF A PLATE-FINNED AIR-COOLED CONDENSER FOR WASTE HEAT

RECOVERY ORCS

Alihan KAYA and Marija LAZOVA, Michel DE PAEPE

Department of Flow, Heat and Combustion Mechanics, Ghent University, Ghent, Belgium

Keywords: Waste Heat Recovery, Organic Rankine Cycle, Condenser Design

Abstract: The study is related to the design sensitivity analysis of a plate-finned tube bundle V-shaped air-cooled condenser

design problem for a range of representative low-temperature waste heat recovery Organic Rankine Cycle (ORC) cases. An

iterative design model is implemented which reveals the thermodynamic and geometric design error margins that occur when

different in-tube prediction methods are used. 19 condensation heat transfer correlations are used simultaneously within arrays of

geometric and thermodynamic variables. Through attained 19 different convective coefficients, a design sensitivity on the

calculated overall heat transfer coefficient, total transferred heat, degree of subcooling, required tube and fin material amount, air-

and refrigerant-side pressure drops is reported.

EFFICIENCY OF A COMBINED DESALINATION AND POWER SYSTEM UTILISING A MULTI-STREAM HEAT

EXCHANGER

Alireza HOSSEINI ARAGHI, Mehdi KHIADANI and Gordon LUCAS

Research in Desalination and Energy Conversion,

School of Engineering, Edith Cowan University

Keywords: Discharge Thermal Energy Combined Desalination (DTECD) and Power System, Compact Multi-Stream Condenser,

Exergy Analysis, Parametric Optimization.Abstract: The aim of this study is to simplify the process of Discharge Thermal Energy Combined Desalination (DTECD) with

Power System by integrating the two existing heat exchangers (condensers) into a new multi-stream one. This system is a heat


32/35


31

recovery unit, which is used to cogenerate water and power. Two shell & tube condensers operate in a closed power cycle and a

desalination system for cooling an ammonia mixture (70% wt.) as a working fluid and condensing a pure vapor respectively. Here,

a multi-stream plate condenser is utilized instead of the two low exergy efficiency shell & tube condensers. The results proved

that the proposed technique leads to improvement in the system performance. The performance of the proposed process was

analyzed by applying parametric optimization.

HEAT TRANSFER OF FLUIDS WITH HIGHLY VARIABLE PROPERTIES IN PLATE-TYPE HEAT EXCHANGERS

Pourya FOROOGHI , Jacob HESS, Bettina FROHNAPFEL and Kamel HOOMAN

Queensland Geothermal Energy Centre of Excellence (QGECE), The University of Queensland, Australia

Institute of Fluid Mechanics (ISTM), Karlsruhe Institute of Technology, Germany

Keywords: Plate heat exchanger, Variable property; Boundary

Abstract: Heat transfer coefficient can deviate from the prediction of conventional correlations in the event of highly temperature

dependent properties. It can be problematic in industrial applications such as power cycles working near critical pressure of the

working fluid considering severe variation of properties in such pressures. The present paper outlines a study on the evaluation of

convection heat transfer coefficient in plate heat exchangers under the above-described conditions. Experiments have been done

on two chevron-type plate heat exchangers with different chevron angles. The effect of property variation is proven. Also, with

help of numerical simulation, the effect of buoyancy was investigated and some minor impact in certain corrugation angles is

suggested.

EXPLOSION-FORMING OF CU-FE MISCIBILITY GAP ALLOY

T. FIEDLER, H. SUGO, K. HOKAMOTO, U. GARBE, E. KISI1, M. VESENJAK

The University of Newcastle, School of Engineering, NSW 2308 Callaghan, Australia

Keywords: Thermal Storage, Explosion-forming, Miscibility Gap Alloy

Abstract: Miscibility gap alloys (MGAs) are envisioned for use as thermal capacitors for the efficient storage and subsequent

discharge of thermal energy. MGAs are created by combining non-reacting metals in a controlled micro-structure. In the

investigated MGA, the fusible phase (copper) is enclosed inside an iron matrix. Upon heating the metallic constituents store

energy in the form of sensible heat whilst increasing their temperature. Energy storage occurs at a fast rate due to the high inherent

thermal conductivity of both metals. After exceeding the melting temperature of the copper, energy is predominantly stored in the

form of latent heat while the fusible phase is liquefied. As a result, a very high volumetric energy storage density can be achieved.

The current study presents a novel approach to manufacture Cu-Fe MGA using explosive compaction.

PERFORMANCE EVALUATION OF A BARE TUBE AIR-COOLED HEAT EXCHANGER BUNDLE IN DRY AND

WET MODE

Neil ANDERSON and Hanno REUTER

Department of Mechanical and Mechatronic Engineering, Stellenbosch University, South Africa

Keywords: Hybrid, e-NTU, heat exchanger, bundle, heat and mass transfer, pressure drop

Abstract: Performance tests have been conducted on a bare tube air-cooled heat exchanger bundle to be incorporated in a hybrid

(dry/wet) dephlegmator. The tube bundle has 25 rows of 19 mm outer diameter tubes with a triangular pitch double the tubediameter. The tube bundle is tested as a wet as well as a dry heat exchanger. The heat and mass transfer coefficients for wet

operation are obtained by means of the Poppe method of analysis and the equations are solved using the Effectiveness-NTU


33/35


32

method, employing the Merkel assumptions of Lef = 1 and negligible evaporation loss. The experimentally determined heat and

mass transfer coefficients for wet operation predict the experimental results within 3 % and a new correlation for the pressure drop

over the tube bundle is presented as the measured air-side pressure drop was found to be 30 % higher than predicted with a

correlation from literature. For dry operation, a new Nusselt number correlation is proposed and compared against various other

correlations found in literature. All were found to be within 10% of the experimental results. The air-side pressure drop over the

dry tube bundle compares favourably to published correlations.

Session VII

Dry and Wet Cooling Towers

Chair: Dr Zhiqiang Guan



34/35


33

INVESTIGATION OF NATURAL DRAFT COOLING TOWER IN CHINA

LI WUQUAN, CHAI JINGYU, ZHENG JINGWEI

Electric Power Planning & Engineering Institute, Beijing, China

Keywords: Cooling tower; Investigation; Trend.

Abstract: Natural draft cooling tower has been widely used in thermal power plant because of its stable operation, lessmaintenance cost and smaller environmental impact. Up to now, hundreds of natural draft cooling towers have been built in China,

including different types and various capacities of conventional cooling towers, sea water cooling towers, flue gas injection

cooling towers, cooling towers with water collecting device and dry cooling towers etc.. A wide range investigation for natural

draft cooling towers had been carried out for the first time by Electric Power Planning & Engineering Institute from May to

October 2013 in China. Based on the collected data and summarized information, the statistical results and conclusive opinions

are deeply analyzed. The development trend of natural draft cooling tower technology is also prospected in this paper. The

investigation results are expected to be a reference for designing and operating natural draft cooling tower in the thermal power

plants.

COOLING ISSUES FOR SMALL-SCALE SCO2 POWERPLANTS

Ingo JAHN, Sam DUNIAM and Anand VEERARAGAVAN

The University of Queensland, Brisbane, Australia

Keywords: Cooling Towers, supercritical Carbon Dioxide.

Abstract: The use of refrigerants and supercritical fluids, such as CO2, as the working fluid in thermodynamic cycle has the

potential to revolutionize power generation. Compared to steam Rankine cycles and open loop Brayton cycles, the advantages are

higher thermodynamic efficiencies and more compact components. This is of particular interest for small-scale renewable energy

systems, such as condensed solar power. However, the highly non-linear properties of the supercritical carbon dioxide, whichallow efficient compression near the critical point (31C) also create new challenges for the heat exchangers and cooling towers.

Depending on the cycle design the cooling tower must be capable of cooling and condensing the fluid from the supercritical

region to the liquid region. This is a particular challenge as recuperation and CO2 properties significantly reduces the air

temperature increase in Cooler.This paper quantifies the cooling requirements and associated cooling issues created by a small-

scale (1MW) solar thermal supercritical Carbon Dioxide power plant operating with a Natural Draft Dry Cooling Tower.

EXPERIMENTAL STUDY OF THE ENERGY PERFORMANCE OF A SPLIT AIR-CONDITIONING UNIT USING

EVAPORATIVE PADS

P. MARTNEZ1, J. RUIZ2, C.G. CUTILLAS2, P.J. MARTNEZ2, A.S. KAISER3and M. LUCAS2

1Dept. of Mechanical and Energy Engineering, Universidad Miguel Hernndez, Elche, Spain

2Universidad Miguel Hernndez, Spain

3Universidad Politcnica de Cartagena, Spain

Keywords: evaporative cooling, split air conditioning unit, energy efficiency.

Abstract: A well known strategy for improving the performance of air conditioning systems when using air-condensed units is to

decrease the ambient inlet airflow temperature by means of an evaporative cooling pad. In this work experiments are conducted in

a split air-conditioning system where the condensing unit is modified by coupling different evaporative cooling pads with variable

thickness. The impact of the different cooling pads on the overall performance of the air-conditioning system is experimentallydetermined by measuring the airflow conditions and the energy consumption of the overall air conditioning system, including both

the condenser fan and the feedwater recirculation pump of the cooling pads. The aim is to determine the energy efficiency


35/35


improvement achieved by pre-cooling the ambient airflow compared to a common air-condensed unit and to calculate the optimal

pad thickness that maximize the overall COP of the system.

DEVELOPMENT AND VALIDATION OF A CFD MODEL

FOR NUMERICAL SIMULATION OF A LARGE NATURAL DRAFT

WET COOLING TOWER

Nicolas BLAIN1

& Matthieu MIOLANE2

1EDF SEPTEN, 12-14 avenue Dutrivoz, 69100 Villeurbanne FRANCE

2OptiFluides SARL, 6 bvd Niels Bohr, Villeurbanne FRANCE

Keywords: Cooling tower, CFD model, Fluent, validation, test facility.

Abstract: lectricit de France (EDF) has commissioned the development of a CFD model, based on ANSYS Fluent v.16, which

includes the specific equations (Poppe and Merkel) describing the physical phenomena occurring in a natural draft wet cooling

tower (NDWCT). Heat and mass transfers between water and air, as well as drag equations for the two-phase system, are

computed in specific zones such as the cooling fill, spray and rain zones. This paper presents the CFD model created and the two-

step methodology implemented for the validation process: The model is first tested and set regarding thermal performance results

obtained on EDF test cell Mistral located on the Bugey site. The Mistral facility includes a 7m x 7m counter-flow section,

equipped with a large number of temperature and pressure sensors, which represents an efficient and reliable mean for cooling fill

performances evaluation. Secondly, the model is fully validated thanks to acceptance tests results gathered from a large scale

NDWCT refurbishment. To this end, advanced instrumentation was positioned in the tower to provide additional data for

extensive validation of the model. The oral presentation during the IAHR Conference will give the audience an insight into what

is currently achievable with the CFD model.

section abstracts

Documents