KTH ROYAL INSTITUTE OF TECHNOLOGY Absorption processes with energy storage Björn Palm
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
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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
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Introduction: The principle of an intermittent absorption system
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Article on Tepidus-system, 1980
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Ca 10m3 Na2S sufficient for seasonal storage for a single family house!
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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
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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!
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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!
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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!
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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
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Properties of the compressor:
• Oil free • Designed for ammonia
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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
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Time plan, after accepted prolongation Månad
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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!