An Investigation of Electrochemical Methods for Refrigeration

Gerlach, D.W.; Newell, T.A.

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https://hdl.handle.net/2142/12345 Copy

Description

Title

An Investigation of Electrochemical Methods for Refrigeration

Author(s)

• Gerlach, D.W.
• Newell, T.A.

Issue Date

2004-10

Keyword(s)

electrochemical processes for refrigeration

Abstract

Electrochemical processes can be combined into thermodynamic cycles that can produce refrigeration effects. The technical feasibility and design parameters of electrochemical refrigeration systems were studied. Modeling of thermodynamic, kinetic, and transport processes have been undertaken. The systems under investigation are divided into two groups: direct methods and indirect methods. Direct methods utilize the heat absorption and rejection associated with the entropy change of reaction that occurs as part of an electrically-driven chemical reaction. Indirect methods use some other aspect of an electrochemical reaction such as pressure production to drive a cooling system. Thermodynamic equilibrium analyses of direct methods have been performed including development of a proof of Carnot limitations. A variety of potential chemical reaction systems have been investigated with respect to feasibility for laboratory prototype systems and future applications. The properties of an ideal reaction system are discussed and several possible reaction types are suggested for investigation. The continuous flow direct method consists of two electrochemical cells operating in reverse of each other with reactants pumped between them via a regenerative heat exchanger. More detailed analyses including irreversibilities have shown technical feasibility. These analyses included ohmic resistance, limitations due to the reaction rate kinetics, mass transport losses, and losses due to the internal regenerative heat exchange process. This model identifies some of the tradeoffs in design and places upper and lower bounds on design parameters such as surface heat flux and COP. The model calculation is based on published measurements of reaction data. The system is very sensitive to losses in the cells because the electricity cycled internally is much larger than the heat transferred externally. Small scale laboratory tests have demonstrated cooling using a D-sized NiCd battery and a cell generating gaseous chlorine and hydrogen from hydrochloric acid. A number of indirect methods for refrigeration are reviewed.

Publisher

Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign.

Series/Report Name or Number

Air Conditioning and Refrigeration Center TR-234

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/12345

Sponsor(s)/Grant Number(s)

Air Conditioning and Refrigeration Project 125

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