solar thermal power plant 2nd presentaion

LAB-SCALE SOLAR THERMAL POWER PLANT

Concept, Design, Simulation & Fabrication

Project Members:Syed Mohammed UmairSulaiman Dawood BarrySaad Ahmed KhanArsalan Qasim

Project Advisor:Cdr. ShafiqDr. Sohail Zaki

Scope of Project

• To harness solar energy

• Selected DSG after comparison of various options

Objectives

• To design and fabricate a lab scale solar thermal power plant and generate about 40W power

• To demonstrate the principle of DSG using solar power

Energy Crisis In Pakistan

• Problems due to use of fossil fuels:

Crude oil is very expensive. Prices had once crossed over $140 per barrel

Rising oil prices lead to inflation

Oil embargo can cripple Pakistan economy

Energy Crisis In Pakistan

• Problems due to use of fossil fuels:

In year 2006, Pakistan imported crude worth 6.7 Billion Dollars (Dawn News)

To finance such a purchase, loans from IMF are needed. This increases debt burden.

Cost Of Energy In Pakistan

Possible Solution

• These problems can be reduced greatly by utilizing RENEWABLE ENERGY and SOLAR POWER IN PARTICULAR.

• Pakistan has vast tracts of desert regions which receive large quantities of solar flux throughout the year.

Power Generation Methods Using Parabolic Troughs

Steam heated with a heat transfer fluid. Steam heated directly by solar radiation. Combined cycle power generation using both solar and

fossil fuel.

Electric Generation UsingHeat Transfer Fluid

Uses parabolic troughs in order to produce electricity from sunlight They are long parallel rows of curved glass mirrors focusing the sun’s energy on an absorber pipe located along its focal line.These collectors track the sun by rotating around a north–south axis.

The HTF (oil) is circulated through the pipes.Under normal operation the heated HTF leaves the collectors with a specified collector outlet temperature and is pumped to a central power plant area.

Electric Generation UsingHeat Transfer Fluid

The HTF is passed through several heat exchangers where its energy is transferred to the power plant’s working fluid (water or steam)The heated steam is used to drive a turbine generator to produce electricity and waste heat is rejected.

Electric Generation UsingHeat Transfer Fluid

Electric Generation UsingDirect Steam Generation

The collectors reflect heat from the sun onto the receiver.Working fluid in the receiver is converted into steamAfter flowing through the super heater the high pressure steam is fed into the turbine/engineThe fluid passes through the condenser back to the feed water tank where the cycle begins again

Electric Generation UsingCombined Cycle

Hybrid system with a gas-fired turbine and a solar fieldSolar energy heats creates steam at daytime while fossil fuel used at night and peak timeThe running cost of the fuel will be reduced due to lesser fuel input.

Our Selection

Weighing all the advantages and disadvantages we have decided to select

Direct Steam Generation method as our project

Selection of Working Fluid

Steam R11 R113 R123 R134a R22 n-pentane0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

Efficiency for Same Working Pressure (140 kPa) for different working fluids in an Ideal Rankine Cycle

Working Fluids

Efficie

ncy

Selection of Working Fluid

• Water– Cheap abundant supply– Non toxic– Non flammable– Close cycle not necessary for operation

Cycle Selection

102 110 120 130 140 150 160 170 180 190 200 210 220 2300

0.01

0.02

0.03

0.04

0.05

0.06

0.07

Efficiency Vs Boiler Pressure

Closed Cycle

Open Cycle

Boiler Pressure

Effici

ency

Closed Cycle Open Cycle

Pressure (kPa) 101 101

Pump Inlet Quality 0.1 N/A

Pump Temperature (°C) N/A 25

Schematic

Design Constraints

• Temperature is 15 K superheat– Conserve engine life– Demonstrate the principle

• Pressure 140 kPa– Limitation of overhead tank– Unavailability of Low Flow rate pumps

Design Constraints

• Black nickel electroplating– Solar selective coating– Easily available

• Tube Length 1.6 meter– Test on existing parabola– Unavailability of Larger electroplating setup

Design Approach

• Mass flow rate• Energy Input

Design for 40 Watts

• Super-heater• Boiler

Heat Distribution • Superheater

Length• Heat Loss• Parabola Width

Optimization

• Drafting• Pressure Analysis

Finalization

Design Approach

• Mass flow rate• Energy Input

Design for 40 Watts

• Super-heater• Boiler

Heat Distribution • Superheater

Length• Heat Loss• Parabola Width

Optimization

• Drafting• Pressure Analysis

Finalization

Design Approach

• Mass flow rate• Energy Input

Design for 40 Watts

• Super-heater• Boiler

Heat Distribution • Superheater

Length• Heat Loss• Parabola Width

Optimization

• Drafting• Pressure Analysis

Finalization

Design Approach

• Mass flow rate• Energy Input

Design for 40 Watts

• Super-heater• Boiler

Heat Distribution • Superheater

Length• Heat Loss• Parabola Width

Optimization

• Drafting• Pressure Analysis

Finalization

Super-heater Surface Temperature against its Length

0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 0.110

200

400

600

800

1000

1200

1400

1600

1800

Superheater Length (m)

Surf

ace

Tem

pera

ture

(°C)

Boiler Analysis

0 0.1 0.2 0.3 0.4 0.5

0.600000000000001

0.700000000000001 0.8 0.92

4

6

8

10

12

14

Heat Transfer Coefficient Vs Water Level

Hea

t Tra

nsfe

r Co-

effici

ents

W/m

2-K Steam

Water

Water

Steam

DANGEROUS!!!

SAFER TO OPERATE

Boiler Analysis

0 0.1 0.2 0.3 0.4 0.5

0.600000000000001

0.700000000000001 0.8 0.91000

1200

1400

1600

1800

2000

2200

2400

2600

Reynolds Number Vs Water Level

Boiler Analysis

0 0.1 0.2 0.3 0.4 0.5

0.600000000000001

0.700000000000001 0.8 0.90.5

1

1.5

2

2.5

3

Entry Length of Thermal Bondary Layer Vs Water Level

Entr

y Le

ngth

of T

herm

al B

onda

ry L

ayer

(m)

Boiler Analysis

Boiling Regime: Nucleate

Safe Operation

Heat Loss Analysis

0.020.05

0.080.11

0.140.17 0.2

0.230.26

0.29

0.3200000000000030.35

0.3800000000000030.41

0.440.47 0.5

0.530

0.2

0.4

0.6

0.8

1

1.2

1.4

0 m/s1 m/s2 m/s3 m/s4 m/s5 m/s

Length of Superheater (m)

Tota

l Hea

t Los

s (k

W)

Boiler Heat Loss Comparison

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Bare TubeGlass Tube

Wind Velocity (m/s)

Hea

t Los

s (k

W)

Super-heater Heat Loss Comparison

0.020.040.060.080.10.120.140.160.180.20.220.240.260.280.30.3200000000000030.340.360.3800000000000030.40.420.440.460.480.50.520.54

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

2 m/s bare2 m/s glass5 m/s Bare5 m/s glass

Length of Superheater (m)

Hea

t Los

s (k

W)

Total Plant Heat Loss For Bare and Glass Tube

0.020.04

0.060.08 0.1

0.120.14

0.160.18 0.2

0.220.24

0.260.28 0.3

0.3200000000000030.34

0.36

0.380000000000003 0.40.42

0.440.46

0.48 0.50.52

0.540

0.2

0.4

0.6

0.8

1

1.2

1.4

Bare Tube with 5 m/sGlass Tube with 5 m/sBare Tube with 2 m/sGlass Tube with 2 m/s

Length of Superheater (m)

Hea

t Los

s (k

W)

Area Required for Each Combination

0.020.05

0.080.11

0.140.17 0.2

0.230.26

0.29

0.3200000000000030.35

0.3800000000000030.41

0.440.47 0.5

0.538

8.5

9

9.5

10

10.5

11

Bare Boiler + Bare SuperheaterBare Boiler + Glass SuperheaterGlass Boiler + Bare SuperheaterGlass Boiler + Glass Superheater

Length of Superheater (m)

Are

a of

Tro

ugh

(m2)

Parabola Width for Boiler and Superheat Sections

0.020.05

0.080.11

0.140.17 0.2

0.230.26

0.29

0.3200000000000030.35

0.3800000000000030.41

0.440.47 0.5

0.531

10

100

Bare BoilerGlass BoilerBare SuperheaterGlass Superheater

Length of Superheater (m)

Para

bola

Wid

th (m

)

Total Efficiency of Plant

0.020.05

0.080.11

0.140.17 0.2

0.230.26

0.29

0.3200000000000030.35

0.3800000000000030.41

0.440.47 0.5

0.530.8

0.85

0.9

0.95

1

1.05

1.1

1.15

Entirely Bare Tube 5m/sEntirely Envoloped with Glass Tube 5m/sEntirely Bare Tube 2m/sEntirely Envoloped with Glass Tube 2m/s

Length of Superheater (m)

Perc

enta

ge E

ffici

ency

(%)

Plant Layout

Variation of Super-heater Surface Temperature and Steam Exit Temperature with Boiler Pressure

120140

160180

200220

240260

280300

320340

360380

0

100

200

300

400

500

600

700

800

Superheater Surface TemperatureSteam Exit Temperature

Working Pressure (kPa)

Tem

pera

ture

(oC)

Variation of Plant Carnot Efficiency, Efficiency with Bare Tube and Glass Tube with Pressure

120130140150160170180190200210220230240250260270280290300310320330340350360370380

0

0.02

0.04

0.06

0.08

0.1

0.12

Carnot EfficiencyThermal Efficiency with Bare TubeThermal Efficiency with Glass Tube

Working Pressure (kPa)

Effici

ency

Heat Loss with Pressure

120130140150160170180190200210220230240250260270280290300310320330340350360370380

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Heat Loss Bare TubeHeat Loss Glass Tube

Working Pressure (kPa)

Tota

l Pla

nt H

eat L

oss

(kW

)

Variation Total Area Required with Pressure

120135

150165

180195

210225

240255

270285

300315

330345

360375

0

2

4

6

8

10

12

14

16

18

Area Required with Bare TubeArea Required with Glass Tube

Working Pressure (kPa)

Tota

l Are

a Re

quir

ed (m

2)

Cost breakupPart CostCopper tube 2,500Black nickel coating 400Parabola frame with mounting 9,000Valves and fittings 5,000Steam engine 5,000Mirror strips 2,500Miscellaneous 1,000Total 25,400

43

FEA Analysis

• Objective:– Determine the deformation in Supporting

Structure– Optimize the flow in the Superheater by• Reducing the vortex region• Reducing the Stagnation Pressure Drop

44

Stress and Strain Analysis

45

Super-heater Analysis

Inlet Region

46

Flow Inlet Angle: 45°

Vortex Region: Largest Stagnation Pressure Drop: Large

47

Flow Inlet Angle: -5°

Vortex Region: Moderate Stagnation Pressure Drop: Moderate

48

Flow Inlet Angle: -55°

Vortex Region: Negligible Stagnation Pressure Drop: Largest

49

50

51

52

53

54

55

56

Manufacturing Operations

57

58

59

60

61

62

63

64

65

Engine Operation Principle

66

Pump

ACHIEVEMENTS

• Presented two papers1. 3rd National Energy Confrence at QUEST

Nawabshah2. SPEC-2010 at NED University Karachi

• Won as Runner up at NED University

68

Conclusion