A lumped mathematical model was established and then experimentally verified according to the photo-thermal conversion process of parabolic trough collector.On this basis

a modular solar simulation system was built and the steady and dynamic characteristics of this system were tested.The results show that

the factors irradiation

fluid inlet temperature and fluid flow have a great effect on operation performances of the heat collection field.When the solar irradiation drops from 900 W/m2 to 0

the system's timeconstant is approximately 5min.While when the fluid flow of 11.4m3/h jumps to 22.8m3/h and drops to5.7m3/h

the system's time-constants are 2.7min and 8.2min

respectively.