Waste Heat Recovery, Absorption Heat Pump, Simulation
This paper presents the investigation of a single-effect ammonia-water absorption system driven by heat rejected from a diesel engine. The waste heat is recovered using an exhaust gas heat exchanger and delivered to the desorber by a heat transfer fluid loop. The absorber and condenser are hydronically coupled in parallel to an ambient heat exchanger for heat rejection. The evaporator provides chilled water for space-conditioning. A thermodynamic model is developed for a baseline cooling capacity of 2 kW and a detailed parametric study of the optimized system for both cooling and heating mode operation is conducted over a range of operating conditions. These parametric investigations show that degradation of system performance can be limited, and improved coefficients of performance achieved, by adjusting the coupling fluid temperature as the ambient temperature varies. With the varying return temperature, the system is able to provide the 2 kW design cooling capacity for the entire ambient temperature range investigated using heat that would normally be wasted by direct rejection to the environment.