CH-85-20-2 -- A Summary of Experience with Stratified Chilled Water Tanks PDF

Due to growing interest in thermal storage for electrical load management, stratified chilled water tanks are being more widely used for storage of cooling capacity. Until recently there has been a severe lack of detailed informat.ion on the performance of this type of storage. This paper reports the results of two types of tests performed on stratified chilled water tanks. These tests involved repeated cycles of operation for both hypothetical and actual load conditions. The results indicate that chilled water tanks consistently stratify well for a range of operating conditions, including normal design conditions, even when an operating strategy that is obviously less than optimum is employed. The tanks exhibited attractive performance such as cycle thermal efficiencies up to 90% if they were completely or almost completely discharged. The results obtained from two different diffuser systems installed in tanks of identical geometry agreed very closely.