VARIABLE-SPEED CAPACITY CONTROL IN REFRIGERATION SYSTEMS

Abstract This paper presents a review of the application of variable-speed capacity control to refrigeration systems. The aim is to put together diversified information in a single source and to appraise recent advances in variable-speed technology. The review reveals that although variable-speed drives based on inverters have been applied successfully to control the capacity of rotodynamic machines, such as pumps and fans, their application to positive displacement machines, such as compressors, has so far been restricted to small-capacity air-conditioning units. There has been only a very small uptake of the technology in the medium-range capacity units, due to a number of problems, such as insufficient development and integration of components, poor reliability, high capital cost and the failure of demonstration installations to produce the expected energy savings. Although inverter-based variablespeed compressor technology offers the potential for energy savings, considerable research work is still required for the development of optimised and cost-effective systems.

[1]  Bimal K. Bose,et al.  Power electronics-a technology review , 1992, Proc. IEEE.

[2]  Savvas A. Tassou,et al.  Investigation into Alternative Compressor Technologies for Variable Speed Refrigeration Applications , 1994 .

[3]  Dennis A. Jarc,et al.  A Graphical Approach to AC Drive Classification , 1987, IEEE Transactions on Industry Applications.

[4]  S. K. Fischer,et al.  Comparative analysis of single and continuously variable-capacity heat pump concepts , 1984 .

[5]  R. S. Colby,et al.  Measured efficiency of high efficiency and standard induction motors , 1990, Conference Record of the 1990 IEEE Industry Applications Society Annual Meeting.

[6]  H. Holdack-Janssen,et al.  Continuous and Discontinuous Capacity Control for High Speed Refrigeration Compressors , 1984 .

[7]  T. Itami K. Okoma,et al.  An Experimental Study of Frequency-Controlled Compressors , 1982 .

[8]  Manabu Sakai,et al.  On the Superior Dynamic Behavior of a Variable Rotating Speed Scroll Compressor , 1988 .

[9]  A K H Wong Variable compressor speed control: Economic evaluation , 1989 .

[10]  Noriaki Ishii,et al.  Mechanical Effic iency of a Variable Speed Scroll Compressor , 1990 .

[11]  T. Senshu,et al.  Annual energy-saving effect of capacity-modulated air conditioner equipped with inverter-driven scroll compressor , 1985 .

[12]  C. K. Rice Benchmark performance analysis of an ECM-modulated air-to-air heat pump with a reciprocating compressor , 1992 .

[13]  J. A. McCovern Performance Characteristics of a Reciprocating Refrigerant Compressor Over a Range of Speeds , 1988 .

[14]  Savvas A. Tassou,et al.  Comparison of the performance of capacity controlled and conventional on/off controlled heat pumps , 1983 .

[15]  Douglas Scholey Induction Motors for Variable Frequency Power Supplies , 1982, IEEE Transactions on Industry Applications.

[16]  T. Yamamoto,et al.  Development of an energy-saving-oriented variable capacity system heat pump , 1982 .