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Indexed by:会议论文

Date of Publication:2009-01-01

Included Journals:EI、CPCI-S、Scopus

Volume:1

Page Number:518-524

Key Words:Two-stage; Heat pump; Low temperature climates; Simulation

Abstract:Numerical calculation as a convenient tool is widely used in one-stage compression refrigeration system to investigate different field problems. This paper focuses on the model of an air-source heat pump (ASHP) for low temperature climates operating in steady-state, which is based on the principle of two-stage compression cycle with two-stage throttling. The full model comprises compressor, expansion valve, heat exchanger and heat recovery unit, which are separately modelled. The models of receiver and flash tank in AMP are not taken into account. The model of compressor neglects the mass variation in it, thus the same mass flow rate at the inlet and outlet of compressor is considered. A lumped method is used to model heat exchangers with phase change, which is chosen in this study in form of epsilon-NTU. As for heat recovery unit modelled, its heat absorption capacity form high-stage compressor is determined by experimental data. These models are coupled by using their input and output variables. The numerical model is validated against experimental data, and the simulation results of the heating capacity and COP compared with experimental data are within +/- 7.4% error bands. This result indicates that the model can be used to predict important system parameters and can reflect the actual behaviour of the system.