The accumulator works as a key component of the mechanically pumped two phase cooling system

and its response characteristics will directly affect the system performance. An experiment and theoretical analysis for the influence of the accumulator pressure on pump startup process

heat startup process and stable operation process were made. The results show that the lower accumulator pressure means the more stable mechanical pump starts owing to the characteristics of working fluid R134a and operating characteristics of the gear pump. Pressure change of the accumulator has low impact on the heat startup process

and the startup apparent stability. In the steady operation stage

the lower accumulator pressure indicates the greater fluctuations of the evaporator outlet temperature.