Variable Capacity Compressor Controller

摘要

An examination was made of one method of improving the operational efficiency of a heat pump. The method involved changing the compression motor speed to vary the capacity of the heat pump to match the load. The first phase developed the variable capacity heat pump design requirements, selected a motor speed control technique, and generated a variable speed controller design. The design requirements were derived by analyzing the effects of varying the compressor speed on each of the major components of the heat pump. Various motor speed control techniques were analyzed, and a method was chosen which could theoretically provide the most efficient operation. This phase was concluded by designing a controller which would vary the compressor motor speed and adjust the elements of the heat pump based upon the structure's heat load requirements. The second phase was the development of the hardware to implement the variable capacity heat pump, using a two-speed heat pump which is a commercially feasible approach to the variable capacity heat pump problem. The controller was implemented using Rockwell 6502 microcomputer, the AIM 65. Results of a heat pump used to air condition a test facility in North Hollywood, California during the month of August, 1979, are discussed. Results on the dual capacity heat pump and controller indicate a 5 to 20% efficiency improvement over a constant capacity heat pump. (ERA citation 06:033448)