A concentrating solar power (CSP) system converts sunlight into a heat source which can be used to drive a conventional power plant. Thermal energy storage (TES) improves the dispatchability of a CSP plant. Heat can be stored in either sensible, latent or thermochemical storage. Commercial deployment of CSP systems have been achieved in recent years with the two-tank sensible storage system using molten salt as the storage medium. Considerable research effort has been conducted to improve the efficiency of the CSP system and make the cost of electricity comparable to that of the conventional fossil-fuel power plant. This paper provides a comprehensive summary of CSP plants both in operation and under construction. It covers the available technologies for the receiver, thermal storage, power block and heat transfer fluid. This paper also reviews developments in high temperature TES over the past decade with a focus on sensible and latent heat storage. High temperature corrosion and economic aspects of these systems are also discussed.

Review on concentrating solar power plants and new developments in high temperature thermal energy storage technologies

Heat transfer fluids for concentrating solar power systems – A review

Thermochemical energy storage of concentrated solar power by integration of the calcium looping process and a CO2 power cycle

Mainstreaming commercial CSP systems: A technology review

Molten salts as engineering fluids – A review

The preparation and properties of multi-component molten salts

This paper focuses on thermal stability of molten salts consisting of potassium nitrate, sodium nitrite, sodium nitrate and one kind of additives such as A, B and C at a high temperature. The multi-component molten salts were prepared by mixing the pure salts, heating statically to the melting state and then cooling to room temperature to form the mixed molten salts. The stability experiments were carried out at 500 and 550°C, and the experiment found that the molten salt with 5% additive A performed better high-temperature thermal stability and its optimum operating temperature was increased to 550 from 500°C. XRD and DSC analyses indicated that the molten salt with 5% additive A had a lower freezing point and a higher phase change latent heat. Besides, the concentration of NO 2 anion in the molten salt was analyzed and the results showed that the main reaction for the molten salts in air was nitrite thermal oxidation at 500 and 550°C. In addition, the energy used for the oxidation of nitrite would be increased with an increase in additives and the prolonging of reaction time at the same time.

High-temperature thermal stability of molten salt materials

The invention provides a molten salt tube-shell type steam generating device and a molten salt tube-shell type steam generating method. The device comprises a tube-shell type heat exchanger, a steam separation output component and a heating and heat preservation component, wherein the steam separation output component is arranged on the top of the tube-shell type heat exchanger, and the heating and heat preservation component is arranged on the outer side of the container wall of the tube-shell type heat exchanger; the tube-shell type heat exchanger is provided with a top tube box, a tube body and a bottom tube box in sequence from top to bottom, wherein the inside of the tube body is provided with tube bundles of which both ends are fixedly connected with the tube body by tube plates, and the gaps between the tube bundles are filled with molten salt; and the outer side of the tube body is provided with a molten salt inlet tube and a molten salt outlet tube, and the bottom tube box is provided with a water inlet tube and a water outlet tube. The method comprises the following steps of: pre-heating the tube body; and orderly performing molten salt filling, hot water filling, and steam separating and outputting. The device has the advantages of big effective heat storage capacity, long-term stable operation, and relatively low manufacturing cost and maintenance cost, and can meet the requirements on large-scale solar mid- and high-temperature heat utilization in industry.

Molten salt tube-shell type steam generating device and method

Steady dynamical behaviors of novel viscous pump with groove under the rotor

The invention discloses a high-temperature molten salt single-tank thermal energy storage device with a movable separation plate and a use method thereof. The thermal energy storage device comprises a tank body, an upper tank cap, a lower tank cap, the separation plate and upright columns, wherein the upper and lower tank caps are respectively arranged at the upper and lower ends of the tank body; a high temperature molten salt inlet/outlet is arranged at the top of the upper tank cap; a low temperature molten salt inlet/outlet is arranged at the bottom of the lower tank cap; an upper end cap and a lower end cap are respectively arranged on the upper and lower parts of the tank body; a high temperature molten salt tank body inlet/outlet is arranged on the upper end cap; a low temperature molten salt tank body inlet/outlet is arranged on the lower end cap; the separation plate which moves up and down in the tank body is arranged in the middle of the tank body; a plurality of upright columns penetrate through the separation plate; and the upper and lower ends of each upright column are respectively fixed on the upper and lower end caps. The use method comprises: use in the thermal energy storage stage and use in the thermal energy discharge stage, wherein the flow directions of the molten salt in the thermal energy storage device are opposite in the thermal energy storage stage and the thermal energy discharge stage. The single-tank thermal energy storage device has the advantages of high effective thermal energy storage capacity per unit volume and simple and compact structure, and is convenient to use and maintain.

Xiaoxi Yang

Papers

The preparation and properties of multi-component molten salts

High-temperature thermal stability of molten salt materials

Molten salt tube-shell type steam generating device and method

Steady dynamical behaviors of novel viscous pump with groove under the rotor

High-temperature molten salt single-tank thermal energy storage device with movable separation plate and use method thereof