Double-stage heat storage trough type solar thermal power generation system

The invention discloses a double-stage heat storage trough type solar thermal power generation system. The system comprises a double-stage trough type solar heat collection field, a double-stage heat storage sub-system and a power generation sub-system. The double-stage trough type solar heat collection field comprises a high-temperature heat collection field and a low-temperature heat collection field and is used for receiving and collecting solar radiation energy. The high-temperature heat collection field is used for converting the collected solar radiation energy into heat of high-temperature heat conducting oil. The low-temperature heat collection field is used for converting the solar radiation energy into heat of low-temperature heat conducting oil. The double-stage heat storage sub-system comprises a high-temperature heat accumulator and a low-temperature heat accumulator. The high-temperature heat accumulator is used for storing the high-temperature heat conducting oil output by the high-temperature heat collection field. The low-temperature heat accumulator is used for storing the low-temperature heat conducting oil output by the low-temperature heat collection field. The power generation sub-system is used for converting the heat of the heat conducting oil into steam, converting the steam into electric energy and outputting the electric energy. By using the system disclosed by the invention, a problem of reduction of heat collecting efficiency resulted from high average heat absorption temperature of a mirror field is resolved; furthermore, problems of high high-temperature resistance performance of the mirror field to the conducting oil, high investment of the conducting oil and high power generation cost are resolved.