| The testing system for the thermal performance of solar collector was quite indispensable to testing and researching high-performance solar collector. The testing system referred to the following four kinds of technology: mechanical-driven technology, automatic control technology, microcomputer control technology and modular programming method. With the help of IPC, the functional unit was effective to be managed and the thermal performance of solar collector was successful to be evaluated.The thesis described the auto-solar tracer, elaborated trace principle, software flow charts and algorithm of sun's orbit. According to the sun's orbit, the stepping motor controlled by IPC made the tracer to face the sun. The tracking error was less than 1°.The testing system was equipped with two-stage temperature control for adjusting the actual temperature to the set value. The controlling error was less than±0.1℃. The thesis described how to increase the temperature measurement accuracy by designing circuit and digit filter and how to adjust the actual temperature to the set value by transducer controlling and PID algorithm with lag compensation.The small given flux was controlled by a transducer using PID algorithm together with numerical treatment. The control accuracy was within±1% of set value.The software of the testing system was developed in this thesis. It was able to automatically complete the thermal performance testing.The system was test respectively in WuHan,KunMing and BeiJing. It turned out that the performance of the system arrived at or over the demands of national standards. It was able to test all kinds of solar collectors factually and exactly.The system had been put into service and had carried out the thermal performance testing of many solar collectors. The thesis compared and analyzed the experimental findings. Some methods were be given to estimate solar collector's performance and some ways were be found to increase the thermal performance of solar collectors. |
