An alternative road transport refrigeration

Abstract

The refrigeration units currently used in road transport vehicles are predominantly of the vapour compression refrigeration (VCR) type. In such a unit. the compressor requires an input of energy in the form of work. Although in smaller systems, the compressor can be belt driven from the main propulsion engine, in large systems, it is normally driven by a dedicated internal combustion (IC) engine. In order to obtain refrigeration, the use of vapour absorption refrigeration (VAR) systems utilising the waste heat in the exhaust gases from the main propulsion unit of the vehicle was experimentally investigated and proved possible. Hence, there is no need for the IC engine and compressor of the VCR system. Money can therefore be saved, and there is a reduction in the weight of the unit. Additionally, the VAR system runs quietly and is almost maintenance-free, and the primary energy used to drive the independent engine of the VCR system can be saved. The study included and experimental investigation into the effect on the performance of the IC engine of introducing the VAR system into the exhaust system and also the provision of appropriate off-road/slow running cooling systems, in order to take account of the reduction in exhaust gas flow in slow running traffic or stationary situations or when the vehicle is parked and cooling is still required.