THERMODYNAMIC ANALYSIS OF ENVIRONMENTAL EFFECT OF IC ENGINE

Abstract

Diesel engines are widely used in various applications, including automobiles (especially in trucks and buses), ships, locomotives, construction equipment, agricultural machinery, and generators. Diesel engines emit high concentrations of nitrogen oxide (NOx) particulate matter (PM) and hydrocarbons (HC) into the environment compared to other fuel engines. These pollutants contribute to smog formation, respiratory problems, and other health issues. PM emissions, in particular, are associated with lung cancer, asthma, and cardiovascular diseases. The combustion of diesel fuel also releases CO2, a major contributor to global warming and climate instability. Diesel engines can have adverse effects on ecosystems and wildlife. Acid rain is caused by the emission of nitrogen oxides and sulfur dioxide (SO2), which can harm aquatic life, vegetation, and soil quality. To minimize the harmful effects of diesel engines, it is necessary to use eco-friendly fuels in the diesel engines either partially or completely replacing conventional fuels. CNG is recognized for its better combustion properties, high calorific value, and lower greenhouse gas emissions compared to diesel fuel. Implementing CNG in diesel engines through the dual fuel technique offers an improved option for the environment. To examine the effects of CNG in dual fuel mode, an experiment with a diesel engine at different compression ratios, engine speeds, and injection pressures was conducted. The energy share of CNG is taken as 0-80% for this experiment. The present experiment evaluated the performance and emission characteristics of diesel/CNG dual-fuel engine. The experimental results were also analysed by using Taguchi method.The experimental results demonstrated significant impacts on performance and emissions when CNG was added to diesel engines in dual-fuel combustion. Compared to single diesel fuel combustion, dual-fuel combustion led to increased brake thermal efficiency (BTE) of up to 43.6% and brake specific vii fuel consumption (BSFC) of 32.46%. Carbon monoxide (CO) and hydrocarbon (HC) emissions were increased by 11.3% and 27.8% while carbon dioxide (CO2), nitrogen oxide (NOX), and smoke opacity were decreased by 13.8%, 15.1%, and 40.2 % in dual-fuel combustion.