Experimental investigation of an automotive air-conditioning system driven by a small biogas engine

A compact air conditioning module run on biogas for rural use is proposed. The research study is to investigate the use of small biogas engine to drive the automotive vapour-compression air-conditioning system. The engine used is single-cylinder, four-stroke gasoline engine with capacity of 125 cm3 and compression ratio of 11:1. The biogas engine can be used to run the air-conditioning system with acceptable operation over a range of speeds and loads. The modular system can operate at a range of cooling loads above 3.5 kW at high coefficient of performance, with the proper speed ratio between the engine and the compressor. Overall primary energy ratio of the modular refrigeration system driven by the biogas engine was found to be maximum at about 1.0–1.2. The performance of the modular system tends to decrease with an increase in engine speed.