Effect of Low Calorific Natural Gas on Performance and Emission Characteristics of Engine

Key Words: Low Calorific Natural Gas(저발열량천연가스), Compressed Natural Gas(천연가스), ThermalEfficiency(열효율), Emission(배기가스), Full-Load Performance, World Harmonized Steady StateCycle(정상상태표준모드), World Harmonized Transient Cycle(과도응답상태표준모드)초록:본연구에서는저발열량천연가스가현재상용되고있는대형천연가스엔진에미치는영향을살펴보기위하여3종류의연료를적용하였다. 전부하운전조건과WHSC 및WHTC 모드테스트를수행하여엔진성능및배기특성을분석하였다. 실험결과전부하실험에서토크성능이9,800kcal/Nm3의발열량을갖는저발열량가스의경우현행천연가스(10,400kcal/Nm3)를사용한결과에비해4.4% 감소하였다. 저발열량연료를사용하였을때일산화탄소, 이산화탄소및질소산화물의배출량은감소하였지만,탄화수소의배출량은증가하였다. WHSC 및WHTC 실험결과저발열량연료에서열효율이증가하였으며배기특성은전부하실험결과와유사한경향을보였다. 저발열량천연가스를사용할경우제원상의출력을만족하기어렵고, 탄화수소의배출이증가하는문제점을확인하였다.Abstract: In this, three types of natural gas were employed to investigate the effect of low-calorific naturalgas on the performance of and emissions from a heavy-duty CNG engine. The performance and emissioncharacteristics were analyzed by conducting a full-load test, WHSC mode test, and WHTC mode test. Theresults showed that the torque of low-calorific natural gas with 9,800 kcal/Nm