Abstract: To improve the heat dissipation performance of the seal end face of fire pump, a differential pressure diversion cooling loop is designed and the influencing factors have been studied. Based on the numerical model of fire pump cooling cycle, the influences of tilt angle and radius of diversion channel and pump speed on heat transfer have been analyzed. The results show that, compared with the inclination angle of diversion channel 15?, the 55? condition's average surface heat transfer coefficient have been increased by 13.2%. Ignoring the mass flow loss, the optimal inclination angle is 55?. With the increase of diversion channel radius, the decreasing trend of solid temperature has been decreased. Considering that the expansion of pipe radius will increase the structural cost and energy loss, 4.5 mm is taken as the design radius value. The cooling channel flow is basically proportional to the pump speed, meeting the heat dissipation requirements at all pump speeds.

Key words: fire pump, differential pressure diversion, cooling circuit, thermal-fluid coupling, numerical simulation