With the deepening application of fuel cells in passenger cars

the problem of cold start in low temperature environment becomes more and more prominent. In order to increase the start speed of fuel cell bus

make the battery work faster in a reasonable temperature range and reduce the energy consumption of cold start process

phase change material(PCM) is introduced into the cold start system of electric reactor. PCM can absorb the waste heat of electric reactor

then the waste heat is released to heat electric reactor during cold start. Based on the simulation platform

the cold start system model of electric reactor is established

and the temperature rise and energy consumption characteristics of positive temperature coefficient thermistor(PTC) independent heating

PCM independent heating and PCM-PTC combined heating are compared and analyzed. The results show that

all the three heating methods can increase the 80 kW reactor from –20 ℃ to 10 ℃

and the power of PTC is 12 kW. The PCM adopts paraffin/expanded graphite composite phase change material(CPCM). The effects of PCM mass on cold start time

energy saving rate and latent heat utilization rate are analyzed under combined heating mode. The results show that

compared with PTC independent heating

PCM-PTC combined heating saves about 33.46%energy consumption and reduces the starting time by 37.40%

and reduces the starting time by 61.00% compared with the PCM independent heating. With the increase of PCM mass

the cold start time shortenes and the system energy saving rate increases

but the latent heat utilization rate of PCM decreases. PCM-assisted cold start system provides an idea for fast start and energy saving of fuel cell engine in low temperature environment.