세정수의 분사조건이 선박 스크러버에 미치는 영향

Abstract

Nitrogen oxides (NOx) and sulfur oxides (SOx), which are major emission pollutants from large diesel engines such as marine engines, cause acid rain, which causes soil and water pollution, and photochemical smog, which is harmful to the human body. In order to satisfy the regulations, various studies are being conducted, and small and efficient wet scrubbers are attracting attention. Sulfur oxide treatment technology using a wet scrubber is known to be preferred due to its low operating cost and can use low-cost high sulfur oil fuel as it is. However, the ship does not always operate at continuous maximum output, and the output changes depending on the situation. If the output decreases, the amount of harmful substances contained in the exhaust gas decreases, and if the output increases, the amount of harmful substances increases. It is necessary to take measures to reduce exhaust emissions according to the change in the load on the engine.In order to improve the performance of exhaust reduction, it is necessary to increase the contact area and time between the washing water and the exhaust gas, and to keep the internal temperature of the scrubber low in order to increase the chemical reaction rate. In this study, the exhaust flow was comprehensively analyzed while changing the injection conditions of possible velocity, pressure, temperature, washing water distribution, and water vapor distribution, such as the effect of the injection angle, the effect of multi-stage injection, the effect of the average diameter of spray droplets, and the effect of the reverse injection. We try to find the optimal design condition of the scrubber by analyzing it. Due to the effect on the vertical and horizontal sections of the entire scrubber, it was confirmed that once the spray angle of the nozzle was 60°, the spraying was effective. In the case of reverse injection, it was confirmed that it was the optimal shape in terms of the cooling effect for reducing sulfur oxides and the collection of particles when it was 1.5 m from the bottom in the case of reverse injection. However, it is judged that the exhaust reduction efficiency of the scrubber will increase as the temperature of the cooling part is greatly lowered and the distribution characteristics of the washing water are improved along with the increase of the water vapor concentration.