디젤엔진의 모터링 압축열을 이용한 요소수의 암모니아 변환에 관한 실험적 연구

Abstract

In this study, we intend to conduct a basic study on whether combustion is possible by supplying ammonia to the combustion chamber using the property of urea water solution being converted to ammonia in the Urea-SCR system. The engine speed was maintained at 900rpm ± 5% and injection quantity of urea water solution was maintained at 0.475g/s. The results are summarized as follows. 1. When comparing the maximum pressure inside the cylinder, it was 46.31bar when only air was compressed, and dropped to 46.13bar when air and urea water were compressed. This is a decrease of approximately 0.38%, and the reason is thought to be due to the endothermic reaction. 2. The theoretical ammonia production amount from 5.5151g/s of intake mass flow rate and 0.3140g/s of urea-water mass injection amount introduced into the cylinder is 1771.11ppm. 3. The average concentration of ammonia measured in the exhaust gas line was 103 ppm. This was only 11.58% of the theoretical production amount. 4. The reason why the ammonia produced in the experiment is small is that the injection angle of the injector is large, so it hits the intake pipe and does not atomize, and the urea water accumulates in the intake pipe, so the amount of urea water flowing through the intake valve is less than theoretical, and the compression temperature inside the cylinder is short enough to maintain the temperature at which thermal decomposition and hydrolysis easily occur. In order to produce ammonia close to theoretical, it is necessary to appropriately modify a small diesel engine using an SCR urea water injection device for automobiles in the future so that more urea water can flow into the cylinder. In addition, it is thought that more research and development is needed, such as adjusting the injection timing during the period when the intake valve is open. It is also thought that it is worth considering a method of direct injection into the cylinder.