Recycling of exhaust cooling capacity of pneumatic engine in cooling system of internal combustion engine

Aiming at making full use of the low-temperature characteristics of pneumatic engine,the technical scheme of applying exhaust from pneumatic engine as cooling media to cool down engine radiator was proposed. Exhaust flow and temperature characteristics of pneumatic engine at different speeds was provided by preliminary experiments. The heat exchange model of pneumatic engine exhaust and cooling system of internal combustion engine was established based on preliminary results,and simulation calculations were conducted. Under different pump flow,the heat transfer capacity and the temperature difference between inlet and outlet when water flows through the radiator were obtained. The results show that,temperature drop and heat transfer increased as the speed of pneumatic engine raised. As pump flow increased,temperature difference reduced,heat transfer enhanced with small increase rate,the increment of temperature difference and heat transfer are the minimum at engine speed of 700 r/ min. With the pneumatic engine speed increased,the range of exhaust cool exergy is small and recovery index gradually increased which means recycling effect of cooling capacity turned better.