Evaluation of a pillow-plate heat exchanger for a pump-circulated CO2 refrigeration system

Abstract

Cold thermal energy storage (CTES) technology integrated into refrigeration systems has been proposed as a solution for peak shaving of refrigeration demands. This paper presents the results obtained from an experimental study to test the performance of a novel plates-in-tank heat exchanger (HEX). The HEX consists of a stack of pillow-plates (PP) that is placed in a container made of stainless steel. The PP is created from two sheets of stainless-steel that are laser-welded together and inflated to create flow channels on the inside. The CTES unit is connected to a pump-circulated CO2 system that represents the secondary circuit in a cascade refrigeration system. The plate stack is immersed in water kept inside the container. Water is the storage media and solidifies and melts during the charging and discharging processes, respectively. The performance of the PP-HEX is evaluated in terms of condensing duty and cooling capacity.