A novel heat recovery VRF system: Principle and cooling performance analysis

Faced with an increasingly severe energy problem and increased demand for indoor comfort, heat recovery VRF systems have demonstrated remarkable potential for energy conservation. However, traditional heat recovery VRF systems need more suboptimal energy efficiency in terms of cooling and dehumidification and fail to guarantee precise temperature and humidity control in specific environments. In this study, a novel heat recovery VRF system that can achieve highly efficient cooling while ensuring precise humidity control is proposed. It can realize four primary operation modes by changing the function of indoor heat exchangers. The results showed that the optimal volume ratio of the two compressor cylinders was 1.4, which was used as the design parameter for the system. Compared to the single-evaporation temperature system, the proposed doubleevaporation temperature system has better energy efficiency and dehumidification capacity in the cooling mode. The cooling coefficient of performance (COP) can be increased by 3.18 %-6.05 %, the compressor energy consumption can be reduced by 3.07 %-7.03 %, and the moisture extraction rate and latent heat ratio of the system can be increased by 5.6 %-33.3 %.