Investigation of fouling mechanisms to guide the design of diesel engine exhaust driven absorption heat pumps

Abstract

Fouling mechanisms in single- and two-phase heat and mass exchangers heated by diesel engine exhaust streams are investigated in this study. Fouling experiments are conducted under steady and transient operating conditions over a range of temperatures, mass flow rates, and flow configurations. The deposition of fouling layers and their effects on thermal resistances and pressure drops are studied and interpreted based on the underlying mechanisms. The results are used to design an exhaust-coupled desorber of a 2.71 kW cooling capacity waste-heat driven ammonia-water absorption heat pump while accounting for the degradation due to fouling. The findings from this work can guide the design of a variety of waste heat recovery systems in stationary and automotive applications.