Performance improvement of alternate temperature systems with ice storage-based internal water loop

Abstract

Alternate temperature systems can be found in many areas, e.g., environmental simulation chambers. Circulated air forced convection and refrigerant bypass adjustment are the common ways to control the temperature of the system (or chamber) to be considered. In this paper, we study modified designs with ice storage-based internal water loop. The internal circulated water is cooled by ice melting and the ice is produced by recovering the refrigerant bypass loss. Two methods to change the performance are used: water cooling of the chamber in constant high temperature stage, and refrigerant subcooling in falling temperature stage. The results show that if there is only the water cooling of the chamber, the compressor ON-time will be shortened. The energy consumption can drop in most cases, but the size of the refrigeration device will increase. If both the water cooling of the chamber and the refrigerant subcooling are adopted, the energy consumption and the size of the refrigeration device can be reduced simultaneously. Dynamic water flow rate is documented, which confirms the feasibility of the accurate temperature control of the chamber. As an indicator of the size of the circulated water pump, the maximum water flow rate is also discussed.