Design of a Variable Drop Variable refrigerant flow system Experimental Setup Based on Refrigerant Flow Characteristics

The Variable Refrigerant Flow (VRF) air conditioning system has been extensively applied in modern buildings. To ensure its operational performance and reliability under real-world conditions, it is essential to conduct simulation experiments in laboratory settings that replicate various installation configurations and operating modes. However, such experimental systems typically require the construction of high-rise testing towers, which not only incur substantial construction costs but also fail to accommodate the diverse spatial arrangements encountered in actual VRF installations. To address this limitation, this study develops a numerical simulation model for refrigerant pressure distribution within VRF piping systems. Based on both experimental data and simulation analysis, a semi-physical experimental platform is proposed. This platform utilizes liquid pump pressurization and valve-induced depressurization to emulate the relative positioning of indoor and outdoor units, as well as the length variations in gas and liquid connecting pipes. The proposed approach significantly reduces the cost of experimental infrastructure and provides a technically feasible solution for supporting the reliability assessment and performance optimization of VRF systems in engineering applications.