Research On Anti-coagulation Project For Thermal Oil Transfer System Of Parabolic Trough Solar Thermal Power Plant

Solar thermal power is an effective way for solving the problem of energy depletion and environmental pollution, and has been developing fast in Europe and America. Currently, the solar energy is being in the commercial growth. Along with the building of a resource-saving and environment-friendly society, China will enter a developing period of using solar thermal power. Parabolic trough solar thermal power is by far the ripest in technique and most commercialized power plant. Most of the parabolic trough solar thermal power plant use thermal oil as the heat transfer fluid, and its freeze point is12℃. Compared with the site environment of solar thermal power plant abroad, China areas, which are suitable for solar thermal power plants, have a lower temperature and greater wind speed. Especially in the winter night and rainy days, the thermal losses of thermal oil transfer system are more greater, and the freezing oil will affect the safe operation of the entire plant. So, there are great practical values in researching on anti-coagulation project for thermal oil transfer system of parabolic trough solar thermal power plant.Based on the typical collector system of50MW parabolic trough solar thermal power plant and the actual weather conditions in typical years of a50MW parabolic trough solar thermal power site of upcoming construction in China, this paper proposed the time sample model under the unit’s operating conditions. Based on the energy conservation principle, heat transfer equation, and working fluid equation of state, this paper established the mathematical model of thermal oil transfer system, and proposed the calculation method of thermal oil transfer system thermal losses.According to the working principle of thermal oil transfer system of parabolic trough solar thermal power plant, this paper established the anti-coagulation modes of thermal oil transfer system. And based on the two projects of thermal oil transfer system, including traditional insulation (rock wool insulation) and vacuum transfer tube insulation, the heat losses of thermal oil transfer system under different anti-coagulation modes were analyzed, and the better anti-coagulation modes in different seasons were got. This paper also quantitatively analyzed the economy of vacuum transfer tubes. The paper’s results have certain instructive significance to the design, operation and control strategy of thermal oil transfer system of parabolic trough solar thermal power plant.