COMPARISON STUDY ON PERFORMANCE AND EMISSIONS CHARACTERISTICS OF LPG AND GASOLINE IN A TWO STROKE SI ENGINE

摘要

In this work a single cylinder two stroke three wheeler SI engine (199.3cc, 6.2 kW and 4500 rpm) was used for the test. The engine manifold was altered to run in LPG mode. The gas carburetor was used here to mix the air and LPG thoroughly. Initially the engine was operated with gasoline in carburetor mode for the constant speed of 3000 rpm at different load. Then the engine was operated with LPG mode at the same speed. The performance and emission parameters were compared with gasoline carburetion mode. The maximum brake thermal efficiency with LPG was 22.3% and that with gasoline was 20.3%. The engine could generally operate with lean mixtures with LPG due to its good mixture formation capability. The brake specific fuel consumption decreased for LPG compared to gasoline. The HC and CO levels were lower considerably at LPG mode compared to gasoline operation. High NO and exhaust gas temperature levels were the main problems with LPG.