CAJ | 학술논문

KM48天然气发动机是在原重型柴油机平台上开发的,由于燃烧温度升高,热负荷增加,原机水套有可能不能满足冷却要求。据此,利用FLUENT软件对其冷却水套进行仿真和改进。结果表明,缸盖排气门侧的三角鼻梁区的冷却液流速仅为0.5~2m/s,不能满足冷却要求。为此提出了两种改善缸盖鼻梁区冷却效果的结构方案,仿真结果表明,在缸盖水套的排气门侧加一个面积为199mm2的上通道时,冷却液的流速可提高到2~2.5m/s,满足冷却要求。
KM48천연기발동궤시재원중형시유궤평태상개발적,유우연소온도승고,열부하증가,원궤수투유가능불능만족냉각요구。거차,이용FLUENT연건대기냉각수투진행방진화개진。결과표명,항개배기문측적삼각비량구적냉각액류속부위0.5~2m/s,불능만족냉각요구。위차제출료량충개선항개비량구냉각효과적결구방안,방진결과표명,재항개수투적배기문측가일개면적위199mm2적상통도시,냉각액적류속가제고도2~2.5m/s,만족냉각요구。
KM48 natural gas engine is developed on the base of original heavy-duty diesel engine. Due to the going up of its combustion temperature and hence the increase in thermal load, the original water jacket no lon-ger meets the cooling requirements. For this, its water jacket is simulated and improved with FLUENT software. The results show that the flow rate of coolant in the triangular nose area at exhaust valve side of cylinder head is only 0. 5~2m/s, which can’t meet the cooling requirements. Therefore, two structural modification schemes are put for-ward to improve the cooling effects. The simulation results indicate that by adding an upper passage with an area of 199mm2 at the exhaust valve side of water jacket, the coolant flow rate there can increase to 2~2. 5m/s, meeting its cooling requirements.