| Nowadays, energy and environmental pollution issues have become increasingly serious. Solar energy has been widespread as a kind of clean and inexhaustible renewable energy. Solar thermal power generation system is the current focus and frontier in the development and utilization of solar energy.Supercritical hierarchical solar collector’s thermal power system has been researched and designed in present thesis. The hierarchical collectors system comprises low, medium and high temperature sections by combination of traditional trough solar heat collecting apparatus and chemical heat pump technologies.Low-temperature section is preheated by regenerative cycle of the steam turbine.Medium and high temperature sections are hierarchical heated by trough collectors and chemical heat pump, so that the temperature conform supercritical steam turbine requirements. The chemical heat pump has a dual role of thermal storage and heating. Supercritical thermal power systems are designed based on solar trough mirror fields and two different chemical heat pumps: Ca(OH)2/ Mg(OH)2 and dual Ca(OH)2 chemical heat pumps. Thermodynamic model is established according to solar collectors, chemistry heat pumps and supercritical steam turbine unit.Simulation platform ASPEN PLUS is used for model calculations. Power generation efficiency, mirror-areas, and the overall cycling performance influencing factors of each program are detailed analyzed. Power generation efficiency of supercritical solar thermal power plants based two different chemical heat pumps can reach 50%and cost of electricity can be 1.59 yuan/k Wh. Power generation efficiency and capacity has been significantly improved compared with the conventional way of solar collectors.In the end, supercritical hierarchical collector’s solar thermal power system is proposed. The use of chemical heat pump highlights the advantages of high power generation efficiency large capacity of the system, and the advantage comes with regenerative feature. Performance and efficiency of traditional solar thermal power plant system is improved. Present thesis proposes a new approach for development of solar thermal power plants. |
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