Energy Performance Analysis of an Air-Conditioning System with Heat Pump Chillers Controlled by Inverters

摘要

This paper presents energy performance analysis of an air-conditioning system withheat pump chillers controlled by inverters. The inverter is attached to the chillers' compressor,and controls the number of revolutions of the motor. As a result, the efficiency of the chillerin a partial load can be largely improved more than in a full load. Although the operationhours of chillers become long, energy consumption in chillers is reducible. The energyperformance is verified by direct measurement and a model-based simulation analysis of asmall office building and the air-conditioning system existing in Tokyo. In the measurement,the energy efficiency of the chillers and primary pumps using inverters is compared withones using no inverters, and the result that the former efficiency is higher than the later isobtained. In the simulation, three cases are carried out. The first is the case that no invertersare used in the air-conditioning system, the second is that the inverters are installed in onlychillers, the third is that the inverters are installed in both the chillers and the pumps. Thoughthe operation hours of chiller and primary pump in the second case are longer than the firstcase, the utilization of inverters can cut down the energy consumption. Furthermore, the thirdcase enhances the energy saving compared with the second case. Consequently, the energyconservation effectiveness of chillers controlled by inverters is clarified in this paper.