System Integration And Performance Optimization Of Central Receiver Solar Thermal Power Plan

Solar thermal power technology is one of effective ways to solve environmental pollution and ecological destruction issues in the 21st century. However, there are two key scientific problems in the current solar tower thermal power plans. Firstly, the exergy destruction is great in the energy conversation process from solar energy to thermal energy; secondly, it is difficult to storage solar thermal energy. Supported by Hi-Tech Research and Development Program of China (863) "Solar thermal power plant simulation and optimization in the unsteady solar collection process", the major aim of this research is to integrate a new solar thermal power plant and disclose the thermodynamic performance of the plant. At the same time, the basic thermodynamic performance of the seawater desalination system combined with the double-effect absorption heat pump is also analyzed in the thesis.In the first part, based on "cascade utilization of energy according to energy level", three solar thermal power plants with two-state heat storage unit and two operation modes are investigated, which are suitable for different size and technical level. These new systems not only solve the contradiction between solar's instability and steam turbine requiring stable operation, but also overcome the great exergy destruction problem in the thermal storage subsystem. With the same energy storage, the power increasing ratio of the selected system is 36.1% compared with that of Solar One system.In the second part, the solar thermal power plant simulation software has been developed with the Fortran language. The annual solar-to-electric efficiency is 8.35%, the cost of electricity is 2.63 yuan / kWh. By the system optimization, the annual efficiency improves 0.65 percentage points and the cost of electricity reduces 0.17 yuan / kWh. Research results have provided a theoretical support for design of the first MW solar thermal power plant in China.In the last part, a new seawater desalination system combined with a double-effect parallel LiBr-H₂O absorption heat pump is proposed in the thesis, which is driven by the steam coming from the parabolic trough solar collector. The results show that the energy consumption of unit fresh water production is decreased by 35.6% compared with the traditional LT-MED-TVC system. The new integrated system provides a new approach to decrease the energy consumption of sea water desalination.