Effect of Intake Air Temperature, Pressure And Fuel Injection Pressure On Low Temperature Combustion (LTC) Engine BY Using Dual Injection Strategy For Pollution Reduction
Authors: Moorthy Bharathiraja , Kamaraj Nithyanandhan , Periasamy Somasundaram , Padmavathy Saji Raveendran , Dwivedi Gaurav , Subramaniam Ranjithkumar 
Published: July 2021

Abstract
Starting from the invention of engines, automobiles require engines for their application. Even though several alternatives have been proposed like fuel cells, engines play the vital role in the automobile sector. In this scenario, the emissions coming out from the engine contributes to the global air pollution at an unbelievable rate. This led the government to enforce strict emission regulations on automobiles. To achieve those regulations several ideas have been proposed so far, which are generally classified into two categories as in-cylinder measures and after-treatment measures. But the thing is after-treatment measures are too costly and also it mainly depends on combustion rate. So obviously in-cylinder controls will be the potential area for the research. Automobile sector not only focused on emissions; it also wants high thermal efficiency in engine. Due to high thermal efficiency and good fuel economy diesel engines are the favorite one in automobiles. But it emits NOx and PM at higher rate. To overcome this issue low temperature combustion (LTC) concept is introduced, added to the objective it can also maintain high thermal efficiency as like as diesel combustion. The problem regarding to LTC are combustion phasing control, transient operations, limited operating range and mainly it contributes to HC and CO emissions while concentrating on reduction of NOx and PM. In the present work, control emissions and combustion phasing of LTC combustion concept by dual injection strategy was studied and the effect of fuel injection pressure, intake air temperature and pressure also studied. The project was done only on partial load with diesel as fuel. Late injection strategy of LTC was used. Results shown that compared to single injection strategy, thermal efficiency was improved by dual injection strategy. Pilot injection timing and mass fraction played a vital role in controlling emissions and improving thermal efficiency. In all intake air temperature, if fuel injection pressure increase result in increase of thermal efficiency, NO emission and decrease of smoke, CO and HC emissions. Likewise in all intake air temperature and fuel injection pressure, if Intake air pressure increase result in increase of thermal efficiency, smoke and decrease of NO, HC and CO emissions. Maximum Indicated thermal efficiency achieved was 38% which was 8% higher than base readings. Lowest NO emission achieved was 187 ppm, that was 68% less than base reading. Lowest smoke achieved was 3% of opacity, which was 75% less than base reading. An overall comparing result, optimized fuel injection pressure is 600 bar, intake air temperature is 310 K, intake air pressure is 107 kPa. At that condition, smoke reduced to 23%, NO reduced to 63%, CO reduced to 75% and indicated thermal efficiency increased to 4% compare to base readings.