Thermal Performance Analysis And Prediction Technology Of Parabolic Trough Solar Collector

With the changes in the world energy system in recent years,the development and application of renewable energy has become the new direction of energy development in all countries in the world.Concentrating solar thermal utilization technology is in a wave of cutting-edge technologies in the field of renewable energy research.Among them,the parabolic trough solar heat collection system has developed rapidly in the field of medium and high temperature due to modular production and mature technology,and has been widely used in actual production and life.Based on the Beijing Yanqing Parabolic Trough Solar Collector’s Photothermal Performance Test Platform,this paper carries out the incident angle correction coefficient experiment test,and then establishes and perfects the trough collector prediction model,and conducts experiments under different working conditions to predict the model Perform verification analysis.In view of the above research purposes,this article mainly does the following research work:(1)Based on the photothermal performance test platform of trough solar collectors,a sun tracking model is established.This chapter analyzes the tracking effect of different incident angles on the tracking system of the test platform through theory and experiment,and studies the accuracy and accuracy of the tracking system of the experimental platform,then optimize the experimental platform based on the theoretical calculation results to reduce the impact of tracking errors on subsequent experimental tests;(2)To obtain the incident angle correction coefficient of the trough solar collector.The calculation formula for testing the incident angle correction coefficient by applying thermal principles is derived theoretically,and the incident angle correction coefficient at different incident angles are measured using the test experiment platform,and the functional relationship between the incident angle correction coefficient and the incident angle is obtained.At the same time,the influence of temperature and DNI on the correction coefficient of incident angle and the law are studied.The results show that temperature has little effect on the incident angle correction coefficient;DNI has a great influence on the incident angle correction coefficient.It is recommended to test within the specified DNI range when testing the incident angle correction coefficient;(3)By establishing the heat transfer model of the trough solar collector,the thermal performance prediction model of the trough collector based on the TRNSYS software platform is developed,and the incident angle correction coefficient tested in this paper is used for different temperatures and DNI conditions.The collector is simulated and calculated and verified with experimental data.The results show that the relative error between the calculation results of the short-term prediction model and the actual calculation results is within 6%.For the stable conditions of long-term northsouth east-west axis tracking,the prediction effect of the outlet temperature of the heat transfer fluid is good,and the relative error is within 6%.The relative error of calculating the effective heat gain is mainly between 5% and 10%.