Li Wenbo,Zhang Hui,Li Shuangliang,et al.Steady-State Simulation Approach of Heat Pump Type Multi-Unit Air Conditioning Systems with Vapor Injection[J].Journal of Refrigeration,
Li Wenbo,Zhang Hui,Li Shuangliang,et al.Steady-State Simulation Approach of Heat Pump Type Multi-Unit Air Conditioning Systems with Vapor Injection[J].Journal of Refrigeration,DOI:10.12465/issn.0253-4339.20250825001.
Steady-State Simulation Approach of Heat Pump Type Multi-Unit Air Conditioning Systems with Vapor Injection
Vapor injection technology can effectively enhance the heating performance of heat pump-type multi-unit air conditioning systems (heat pump VRF) under low-temperature conditions. However, complex system configuration and component coupling necessitate a more general steady-state simulation approach for VRF heat pumps. This study proposes an improved graph-theory-based steady-state simulation method for a multiunit air-conditioning system with vapor injection. By abstracting the components into computational units, a graph-theory-based description method guided by the refrigerant flow paths was established. A directed graph of computation units was employed to characterize the adjacency relationships in cooling/heating modes, with mode switching achieved using a four-way valve model. A dual-layer path generation method for system pressure and flow paths is proposed, along with a decoupled iterative algorithm for flow pressure calculation. Validation based on experimental data from a heat pump VRF system with vapor injection (four indoor units) shows that the model prediction error is within ±5% under rated cooling/heating conditions. A steady-state simulation platform with customizable system configurations was developed based on the proposed method, providing a convenient digital tool for the VRF system design.
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