KTH ROYAL INSTITUTE OF TECHNOLOGY

Absorption processes with energy storage Björn Palm

Overview

• Introduction and history • Application in this project • Current status and Continued work

2

Basic facts about the project

• Time period: 2015 04 01 – 2016 12 31 2016 04 01 – 2017 12 31 • Total Budget: 1 500 000 sek • Main applicant: Björn Palm • Organization: KTH/Energy Technology/Applied thermodynamics

and Refrigeration • Co-financing company: ClimateWell

3

Introduction: The principle of an intermittent absorption system

5

Article on Tepidus-system, 1980

6

7

8

9

10

Ca 10m3 Na2S sufficient for seasonal storage for a single family house!

11

How it works

Storage (Stand by)

Absorption

How it works

Regeneration/ Desorption

Reactor Condenser/Evaporator

Thermal Energy Storage Options – Thermochemical’s Key Advantage

Based on Corey Blackman

Heat Storage Densities

Enthalpy of dilution

Enthalpy of dilution + Enthalply of dissolution

Enthalpy of dilution + Enthalpy of dissolution + Enthalpy of hydration

Based on Corey Blackman

Thermochemical Storage

Use of a reversible chemical reaction or physiochemical process to store thermal energy

• Adsorption • Absorption • Chemical Reaction (hydration;

solid gas reaction)

Sorption

Main Advantages

• High Energy Storage Density • Long term storage with few

losses • Combined hot and cold

storage

Based on Corey Blackman

Water vapor pressure over water and over Na2S

18

Triple-Phase Thermochemical Storage Cycle

Based on Corey Blackman

Triple-Phase Absorption

ClimateWell

ClimateWell Components

Applications/ Customer Products

CoolStore Verdacc HeatBoost

Solar Heating, Cooling & Energy Storage

Heat-driven A/C for Lorries & Vehicles

Energy-efficient Water heaters &

Boilers

www.climatewell.com

The Solar Chiller

• Seasonal Storage?

• Solar Air Conditioning?

Cooling of Lorries & Heavy Duty Vehicles • Significant concern over heavy

duty vehicle emissions levels – electrification and biofuels are long to medium term solutions.

• Lorries like most motor vehicles have to run the engine for air conditioning even when not in motion.

• For long distance travel drivers often sleep in the vehicles and if air conditioning is required they need to run the engine.

• Alternatively a battery-driven air conditioner is employed.

Based on Corey Blackman

Project Background

The end-users for the Waste Heat-Driven HVAC (WHHVAC) system will be operators and owners of Heavy Duty Vehicles (HDVs) such as excavators, dumpers, wheel loaders, agricultural vehicles off-highway (articulated and mining) trucks as well as on-highway trucks and buses.

Based on Corey Blackman

WHD Air Con System Requirements

Each WHD Air Con Unit should have:

Cooling power: 3 to 8 kW

Cooling Autonomy

Low System Volume

Based on Corey Blackman

Operation Process of WHD Air Con System

•Batch Process

•Step 1 – Start: Reactor (R) is saturated with refrigerant

•Step 2 – Charge (or Desorption): Heat added to Reactor and refrigerant moves to the Condenser/Evaporator (C/E). As refrigerant condenses heat is rejected from the C/E

•Step 3 – Discharge (or Absorption): The Reactor is cooled and liquid refrigerant from the C/E flows to the reactor as vapour. The phase change from liquid to vapour produces a cooling effect that can be harnessed

•Step 4 – End: Reactor (R) is once again saturated with refrigerant

Salt + Matrix Complex Salt Is a hygroscopic substance, typically an alkali halide that reacts reversibly and spontaneously with a given inorganic compound. Special attention is paid to salt preparation methods.

Refrigerant Inorganic compound that reacts with the salt in the WHD Air Con component. Special attention is given to ensure that this substance has minimal detrimental effects on the environment. Typical substances used are water, methanol and ammonia.

Matrix The matrix is a proprietary material that holds the salt in place and enables optimisation of the heat transfer, mass transfer and chemical reaction processes during the sorption process.

Salt + matrix complex This is used to describe the combination of the specially prepared salt embedded in the matrix.

Basic WHD Air Con System Concept

R1

R2

HX

Engine Waste Heat

C

E

Experimental Investigations: Methodology

HS

RB RA

HS-hxb

PhsbTutb

TinbM MVb

FMb

Tmvb

Tha

Phsa

TinaM

FMa

Tmva

Tuta

MVaHS-hxa

Heater A

HSa-hx

Pra

Heater B

Thb4 Test rigs

• Comparative Testing:

• Thermodynamic property verification

• Salt + Matrix Complex optimisation

• Matrix Preparation Testing:

• Power Density

• 2 x Prototype Testing:

• Power Density • Temperature Lift Sensitivity • Calibration of theoretical model

Measured Quantities:

• Flow • Temperature • Electric Heating Power • Refrigerant Pressure

Experimental Investigations: ¼ Scale Prototype 1

Full Performance Investigation Evaluation: • Nominal Cooling Power • Temperature Sensitivity of Cooling Power • Cycle time optimisation

HS

RB RA

HS-hxb

PhsbTutb

TinbM MVb

FMb

Tmvb

Tha

Phsa

TinaM

FMa

Tmva

Tuta

MVaHS-hxa

Heater A

HSa-hx

Pra

Heater B

Thb

Innovation: Introduce a compressor to speed up the process!

33

HS

RB RA

HS-hxb

PhsbTutb

TinbM MVb

FMb

Tmvb

Tha

Phsa

TinaM

FMa

Tmva

Tuta

MVaHS-hxa

Heater A

HSa-hx

Pra

Heater B

Thb

Innovation: Introduce a compressor to speed up the process!

34

HS

RB RA

HS-hxb

PhsbTutb

TinbM MVb

FMb

Tmvb

Tha

Phsa

TinaM

FMa

Tmva

Tuta

MVaHS-hxa

Heater A

HSa-hx

Pra

Heater B

Thb

Innovation: Introduce a compressor to speed up the process!

35

HS

RB RA

HS-hxb

PhsbTutb

TinbM MVb

FMb

Tmvb

Tha

Phsa

TinaM

FMa

Tmva

Tuta

MVaHS-hxa

Heater A

HSa-hx

Pra

Heater B

Thb

Advantages of using a compressor:

• The power can be increased when required • The time for recharging can be reduced • Very high ambient temperatures can be accepted during

cooling • Low temperature heat sources can be used for charging • The weight and the volume of the device can be reduced

36

Properties of the compressor:

• Oil free • Designed for ammonia

37

Goal of the project:

• To demonstrate a working system based on commercially available components

• To demonstrate experimentally a power increase by 150% • To design a simulation tool for the process

38

Time plan, after accepted prolongation Månad

1603

16

04

1605

16

06

1607

16

08

1609

16

10

1611

16

12

1701

17

02

1703

17

04

1705

17

06

1707

17

08

1709

17

10

1711

17

12

Aktivitet Paket 1 Modellering av systemet

Definition av köldmedium Definition av lämplig kompressor Definition av övriga komponenter Modellering Test av system vid olika förhållanden med hjälp av modellen Modifiering av modellen baserat på experimentella resultat

Paket 2 Experimentell verifiering av modell Design och konstruktion av testrigg Definition av mätutrustning, beställning, inköp, montering, kalibrering, testkörning av rigg Verifieringskörningar under olika förhållanden, jämförelse med den numerisk modellen Vid behov test med alternativ kompressor och alternativt köldmedium

Paket 3 Rapportering Teknisk artikel för fackpress Vetenskaplig artikel, Jämförelse mellan modell-resultat och praktiska prov i provrigg. Poster för KoVP-dagarna Populärvetenskaplig artikel Slutrapport

Conclusions

• The triple-phase thermochemical storage substances have large energy storage potential – with energy densities ranging from 250 to 670 kWh/m3.

• A test rig without compressor is available at ClimateWell • A new test rig with compressor will be designed in the

project

• Selection of refrigerant completed: Ammonia

• Selection of compressor is ongoing

Thank you for your attention!