Thermal balance test of LNG engine at different coolant temperatures

Thermal balance of the LNG (liquefied natural gas) engine were tested on overall conditions at four different coolant temperatures, which were set at 60°C, 70°C, 80°C and 90°C in the tests. The testing results show that coolant temperatures have influence on the heat distribution of the LNG engine. As coolant temperature climbs, proportion of useful power increases and less proportion of heat are taken away by coolant, resulting better fuel economy but more NO_x emission. The coolant temperature influences HC and CO emissions, although in unobvious ways.