Research On Performance Test Method Of Large-scale Parabolic Trough Solar Thermal Power Plants

Since the 1980 s,dozens of large-scale parabolic trough solar thermal power plants have been put into commercial operation in China and abroad.However,up to now,there is no international or national standard for the overall plant performance test method of the solar thermal power plant.The intermittency of solar energy,the diversity of the operation modes and the accuracy of solar radiation intensity measurement are the main difficulties in the research of performance test method.Based on this background,this paper proposes short-term and continuous multi-day performance test methods for the solar thermal power plant.The steady-state and dynamic performance model of parabolic trough solar thermal power plants are studied.The main energy loss in parabolic trough solar system are analyzed.The steady-state model of the parabolic trough solar thermal power plant is built with EBSILON simulation software.According to the change of solar radiation intensity,four different solar thermal power plant’s operation modes are analyzed,and full load heat balance diagram of the pure solar thermal power generation mode and that of the solar thermal power generation and thermal storage mode are obtained by simulation calculation.The dynamic simulation model of the solar thermal power plant’s solar field system and energy storage system are established.The temperature control strategies of the two subsystems in the actual operation processes are simulated in order to simulate the operation of a parabolic trough solar power station for continuous multi-day performance.The performance test method for parabolic trough solar thermal power plants under the short-term and steady-state conditions is presented.The guarantee operation mode and its boundary conditions are determined.Aiming at the problem that the operation mode of guarantee conditions and test condition of the solar thermal power plants station is inconsistent,a conversion method of performance calculation is proposed,which converts the performance results from the solar thermal power generation and thermal storage mode into the pure solar thermal power generation mode.The requirements for operation condition,measuring points and test instruments are Confirmed,and the calculation and correction method for overall plant efficiency and uncertainty analysis are given.The main difficult problems in the long-term performance test of solar thermal power plants are analyzed and studied,and a continuous multi-day performance test method for parabolic trough solar thermal power plants are presented.The test boundary and conditions are given.The effects of the number of measuring points and type of instruments on the uncertainty of DNI are analyzed,in addition,the influence of thermal storage on power generation are studied and correction curves are provided.Based on the test condition and instruments arrangement,power generation of 50 MW parabolic trough solar thermal power plant in one day is calculated by using the performance simulation model.