A molten salt steam generating system capable of variable load operation within the full parameter range

Abstract

The invention provides a molten salt steam generating system capable of variable load operation within a full-parameter range. The system comprises a deaerator, a water feeding pump, a pre-heater, an evaporator, a steam bag, a super heater, a hot salt tank, a hot salt pump and a cold salt tank, wherein water working mediums pass the deaerator, the water feeding pump, the pre-heater, the evaporator, the steam bag and the super heater in sequence, and molten salt working mediums pass the hot salt tank, the hot salt pump, the super heater, the evaporator, the pre-heater and the cold salt tank in sequence; after saturated water in the steam bag and water fed by the water feeding pump are mixed by the steam bag through a circulating pump, the mixed water enters the pre-heater; a bypass adjusting valve of the evaporator is arranged between an inlet and an outlet of the evaporator and used for adjusting the amount of the saturated water flowing through the evaporator; a hot salt distribution adjusting valve is connected between an inlet and an outlet of the super heater and used for adjusting the molten salt amount flowing through the super heater. The molten salt steam generating system achieves the purpose that qualified steam can be generated under different working conditions, and therefore a steam turbine can normally operate under different loads.

Description

technical field [0001] The invention belongs to the technical field of solar thermal power generation, and is a molten salt steam generating system capable of variable load operation within a full parameter range. Background technique [0002] Solar thermal power generation technology has a history of more than 30 years from the original SolarOne project, and it has various forms, such as tower type, trough type and dish type. The solar energy directly generates steam to drive a steam turbine to generate electricity, or use other storage The thermal working medium stores heat energy, and then uses the heat exchange between the thermal storage working medium and the water working medium to generate steam to drive the steam turbine to generate electricity. Sodium nitrate and potassium nitrate binary mixed molten salt with a mass ratio of 6:4 is currently the most widely used heat storage working fluid, and its normal working temperature is between 290°C and 565°C. During the ...

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Problems solved by technology

The common steam generation system for molten salt heat storage power generation is largely borrowed from the boiler of thermal power generation system, and there are two main structural forms: one is to use a kettle heat exchanger in the evaporation section, and the molten salt goes through the tube side , the water working medium is vaporized on the shell side, and the head space of the tank heat exchanger is used for steam-water separation to generate saturated steam, and then enters the superheater for superheating. It is relatively strong, and at the same time, the water in the evaporator goes to the shell side, which can realize sewage discharge and prevent water scaling in the heat exchanger from affecting the heat transfer effect. The disadvantage is that the water side flow rate of the kettle evaporator is slow, resulting in poor variable load capacity

Another structural form is similar to a once-through boiler, using a shell-and-tube heat exchanger. The whole hydraulic fluid goes through the tube side, and the molten salt goes through the shell side. From the liquid water into the heat exchanger, it goes through several stages of heat exchange to become superheated steam. The advantages of this structure are: strong variable load capacity, capable of meeting the requirements of systems with large load changes. The disadvantages are: the system has no steam drum, poor anti-interference ability, high control requirements, no sewage design, easy to scale, and water quality. High standard

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