Heating load, heating load density and COP optimisations for an endoreversible variable temperature heat reservoir air heat pump

Abstract

AbstractThe performance optimisation has been studied for an endoreversible air heat pump with variable temperature heat reservoirs by taking heating load, coefficient of performance (COP) and heating load density, i.e. the ratio of heating load to the maximum specific volume in the cycle, as the optimisation objectives in this paper. The analytical relations of the heating load, the COP and heating load density are derived. The effects of pressure ratio, the effectiveness of the heat exchangers and the inlet temperature ratio of the heat reservoirs on the heating load, the COP and the heating load density are analysed. The cycle performance optimisations are performed by searching the optimum distribution of heat conductance of the hot and cold side heat exchangers for fixed total heat exchanger inventory and the optimum heat capacity rate matching between the working fluid and the heat reservoirs. The air heat pump plant design with heat loading density optimisation leads to a smaller size including the...