Experimental investigation of a solid/gas thermochemical storage process for solar air-conditioning

This paper focuses on the experimental performances of a solar air-conditioning pilot plant for housing, which is running in PROMES laboratory (Perpignan-Odeillo, France) since 2006. This pilot of daily cooling capacity of 20 kWh consists of a solid/gas thermochemical sorption process which is powered at 60–70 °C by 20 m2 of flat plate solar collectors. The thermochemical sorption process is based on the coupling of a liquid/gas phase change of a refrigerant (NH3) and a reversible chemical reaction between a reactive solid (BaCl2) and this refrigerant. Its functioning mode is intrinsically discontinuous and cyclic. It is relevant for the storage or transformation of solar energy. An analysis of 2-years experimental working of the prototype leads to an averaged yearly efficiency of solar collectors and a process COP ranging respectively from 40 to 50% and 30–40%. This prototype enables thus a daily cooling productivity at 4 °C of about 0.8–1.2 kWh of cold per m2 of flate plate solar collector and leads to a global solar COP ranging from 15 to 23%. ► A new solar driven air-conditioning pilot of a daily cooling capacity of 20 kWh is investigated. ► 2-years experimental performances of this solid/gas thermochemical process are discussed. ► A daily cooling productivity at 4 °C of about 0.8–1.2 kWh/m2 of collector is achieved. ► The overall solar COP is ranging from 15 to 23%.