Experimental analysis of a diesel engine driven water-to-water heat pump

Abstract The paper describes the experimental analysis of a diesel driven water-to-water heat pump. The system was developed utilising commercially available equipment with, wherever possible, a minimum of modifications. Heat was extracted from water at ambient temperature by the evaporator and delivered to water at the condenser. Heat from the engine cooling water and exhaust system was also recovered, at a power less than that of the condenser, but at greater temperature. Therefore three distinct streams of heated water were available. The system was of medium size with a total output ranging from 7.5 to 13.5 kW. The system and component performance was determined over a range of compressor speeds, evaporating and condensing pressures. The heating coefficient of performance ranged between 2.7 and 7.3 while the ratio of the total heat output to the heating value of fuel supplied to the engine was found to be between 1.3 and 2.6.