Research and Development of Highly Energy-Efficient Supermarket Refrigeration Systems. Volume 3. Evaluation of a Test System in a Supermarket

摘要

This report covers in detail the engineering evaluation of a highly energy-efficient supermarket refrigeration system. The primary components of this system were a set of three unequal parallel compressors, a microprocessor-based compressor controller, and floating head pressure for condenser operation. For this evaluation, such a system - referred to here as the test system - was designed, fabricated, installed and instrumented in a supermarket operated by the H.E. Butt Grocery Co., in San Antonio, TX. A second refrigeration system - referred to here as the reference system and located in another HEB supermarket in San Antonio - was also instrumented so that comparative measurements between the two systems could be made. The major components of the reference system were two equal parallel compressors, a solid state compressor controller, and conventional head pressure control. The two systems were monitored for a period of approximately one year. The results showed that the test system produced a system EER (energy efficiency ratio) that was on the average 15.9% higher than that of the reference system. Further analysis of the performance data showed that the following parameters (presented in descending order of importance) contributed to this improvement: Operation of the test system at higher suction pressure; cycling control strategy for the test system condenser fans; fewer defrosts experienced by the test system; and operation of the test system at lower condenser pressure. Similar analyses were carried out for the power consumptions and refrigeration loads of both the test and reference systems. 9 figures, 10 tables. (ERA citation 10:020891)