Numerical performance assessment of an innovative PV-driven air-conditioning system based on hydraulic vapour-compression concept for off-grid rural houses
Résumé
The paper presents the results of a performance analysis of an innovative air conditioning system. A new concept of refrigerant compression that consists of a hydraulic compression process is analysed. The process is based on the movement of a liquid piston, enabling a quasi-isentropic compression of the refrigerant. This hydraulic compressor handles the refrigerant in a two-phase state. This prevents superheating of the refrigerant, which negatively impacts refrigeration systems' performance. Additionally, the design of the system allows a slow motion of the liquid piston with negligible friction losses during refrigerant compression. As a result, the air conditioning system can operate according to a quasi-reversed Carnot thermodynamic cycle. The system modelling and design were performed using the open-source tool Open-Modelica. The study focussed on a 3.5 kW cooling capacity system for a rural house located in the Algerian continental climate zone. The results show that the hydraulic-based air conditioning system achieves a COP of almost 4.5 while consuming 35% less energy than a conventional vapour compression air conditioner. Thanks to this efficient compression technology, a preliminary sizing study highlighted that a PV-driven air conditioning system can potentially be a viable solution for off-grid rural houses in desert climate zone.