A molten salt solar thermal power generation system operating all day and an operation method thereof

Abstract

The present invention provides a molten salt solar thermal power generation system and its operation method that operates all day, including a solar thermal collection system, a sustainable molten salt heat exchange and storage system, and a multi-energy coupling power generation system. When the sustainable molten salt heat exchange and storage system operates under insufficient light, the low-temperature molten salt pipeline valve is closed, and the high-temperature molten salt tank can continue to transport molten salt to the gas turbine. The high-temperature molten salt stored in the tank is sufficient for the system to generate electricity normally for several hours. When the molten salt in the low-temperature molten salt tank reaches the set liquid level, the electric heater pipeline valve is opened, and the low-temperature molten salt is transported to the electric heater through a molten salt pump for heating and then passed to the high-temperature molten salt tank to continue the molten salt system circulation; the electric heater uses electricity from wind power generation, which not only improves energy utilization, but also increases the power generation within the cycle. The operation of the entire molten salt solar thermal power generation system that operates all day is now completed.

Description

Technical Field

[0001] The present invention belongs to the field of new energy technology, and specifically relates to an operating system for molten salt solar thermal power generation that operates all day long. Background Art

[0002] Driven by the "dual carbon" goals today, the development and utilization of renewable energy has become an inevitable choice for the sustained and stable operation of China's power system.

[0003] Solar energy is an inexhaustible, renewable and clean energy source, so solar power generation technology has been vigorously promoted and used throughout the world. Currently, the more mature solar power generation technologies on the market include photovoltaic power generation and solar thermal power generation.

[0004] Photovoltaic power generation can only generate electricity under light conditions, so photovoltaic power generation can only work during the day and cannot generate electricity at night. However, most of the residential and industrial electricity consumption is at night. The working characteristics of photovoltaic power generation do not conform to our living habits and cannot meet the continuous and stable electricity demand of residents and industrial electricity.

[0005] As a new energy power generation technology with flexible and adjustable output power, CSP fills the gap of photovoltaic power generation and can meet the needs of safe and stable power supply of power system. However, CSP also has problems such as insufficient energy storage time and high energy consumption of molten salt reheating system, which restrict the development of CSP technology to a certain extent. Therefore, optimizing CSP system has become the focus of the industry. Summary of the invention

[0006] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a 24-hour operation system and method for molten salt solar thermal power generation, which can generate sustainable electricity based on solar energy by using molten salt for heat exchange.

[0007] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0008] In a first aspect, the present invention provides a molten salt solar thermal power generation system that operates all day, including a solar thermal collection system, a sustainable molten salt heat exchange and storage system, and a multi-energy coupling power generation system;

[0009] The sustainable molten salt heat exchange and heat storage system is respectively connected to the solar thermal collection system and the multi-energy coupling power generation system.

[0010] Furthermore, the solar thermal collection system includes a trough-type thermal collection mirror field, a low-temperature molten salt transmission pipe, and a high-temperature molten salt transmission pipe; the sustainable molten salt heat exchange and heat storage system includes a low-temperature molten salt tank and a high-temperature molten salt tank;

[0011] The trough-type solar collector field is equipped with a molten salt transmission pipe, and the input end and the output end are respectively connected to the low-temperature molten salt transmission pipe and the high-temperature molten salt transmission pipe; and are respectively connected to the low-temperature molten salt tank and the high-temperature molten salt tank of the sustainable molten salt heat exchange and storage system through the low-temperature molten salt transmission pipe and the high-temperature molten salt transmission pipe.

[0012] Further, the sustainable molten salt heat exchange and heat storage system includes an electric heater, a high-temperature molten salt tank, a molten salt pump, a molten salt steam generator, a feed water preheater, a low-temperature molten salt tank, valve I, valve II, valve III and valve IV;

[0013] The input end of the high-temperature molten salt tank is respectively connected to the electric heater and the high-temperature molten salt transmission pipe, and the output end of the high-temperature molten salt tank is connected to the molten salt steam generator;

[0014] The input end of the low-temperature molten salt tank is connected to the feed water preheater, and the output end is connected to the electric heater and the low-temperature molten salt transmission pipe respectively;

[0015] The high-temperature molten salt tank, the electric heater and the low-temperature molten salt tank form a series structure; the molten salt steam generator and the feed water preheater are connected in series;

[0016] The molten salt pump is arranged in the sustainable molten salt heat exchange and heat storage system, and is used to provide pumping force for the molten salt;

[0017] The valve I is arranged between the low-temperature molten salt transmission pipe and the low-temperature molten salt tank, and is used to control the input of the low-temperature molten salt to the trough-type solar collector field, and is opened when the sunlight is sufficient, and closed when the sunlight is insufficient;

[0018] The valve II is arranged between the electric heater and the low-temperature molten salt tank, and is used to control the input of the low-temperature molten salt to the electric heater. It is opened when the molten salt in the low-temperature molten salt tank reaches the set liquid level, and is closed when the light is sufficient.

[0019] The valve III is arranged between the feed water preheater and the low temperature molten salt tank, and is used to control the input of the low temperature molten salt into the low temperature molten salt tank;

[0020] The valve IV is arranged between the electric heater and the high-temperature molten salt tank, and is used to control the inflow of the heated molten salt into the high-temperature molten salt tank. It opens when the molten salt in the low-temperature molten salt tank reaches the set liquid level, and closes when there is sufficient light.

[0021] Furthermore, there are multiple molten salt pumps, which are respectively installed between the high-temperature molten salt transmission pipe and the high-temperature molten salt tank, between the high-temperature molten salt tank and the molten salt steam generator, between the electric heater and the low-temperature molten salt tank, between the low-temperature molten salt tank and the low-temperature molten salt transmission pipe, and between the low-temperature molten salt tank and the feed water preheater.

[0022] Furthermore, the electric heater comprises a high-temperature molten salt outlet pipe, an electric heater housing, a molten salt pipe, an electric heating wire and a low-temperature molten salt inlet pipe;

[0023] The low-temperature molten salt inlet pipe and the high-temperature molten salt outlet pipe are respectively located at the input end and the output end of the molten salt pipe; the electric heating wire connected to the wind power generation control component is wrapped around the outside of the molten salt pipe;

[0024] Further, the high-temperature molten salt tank includes a metal outer plate layer, an insulation plate layer, a temperature sensor, a control panel, a float type liquid level sensor, refractory bricks, an insulation rock wool board, a cooling vent, an inner tank heat-resistant partition, a vacuum insulation layer, a ceramic fiber insulation layer and a concrete base;

[0025] The high-temperature molten salt tank is divided into upper, middle and lower parts; the upper part is a vacuum cavity between the metal outer plate layer and the insulation plate layer; the middle part is a multi-layer surround cavity, which includes heat-resistant molten salt cavity, inner tank heat-resistant partition, vacuum insulation layer, ceramic fiber insulation layer and metal outer plate layer from inside to outside; the lower part is closely attached with refractory bricks and insulation rock wool board; the bottom is a concrete base with cooling vents;

[0026] A temperature sensor and a float-type liquid level sensor are provided in the heat-resistant molten salt chamber inside the heat-resistant partition of the inner tank, and the two sensors are monitored and controlled by an external control panel;

[0027] The internal structure of the low-temperature molten salt tank is exactly the same as that of the high-temperature molten salt tank.

[0028] Furthermore, the molten salt steam generator includes a high-temperature molten salt inlet, a medium-temperature molten salt outlet, a high-temperature steam outlet, a steam generator shell, an insulation layer, a mesh plate, a high-temperature molten salt box, a molten salt tube, a heat dissipation fin, a medium-temperature molten salt box and a water inlet;

[0029] The heat-insulating layer is built into the steam generator shell; a mesh plate is provided on the upper part of the inner cavity of the steam generator shell;

[0030] One side of the high-temperature molten salt inlet is connected to the heat-resistant molten salt chamber of the high-temperature molten salt tank through a molten salt pump, and the other side is sequentially connected to the high-temperature molten salt box, the molten salt pipe, the medium-temperature molten salt box to the medium-temperature molten salt outlet;

[0031] Multiple groups of heat dissipation fins are evenly distributed on the molten salt tube;

[0032] The medium-temperature molten salt outlet and water inlet are connected to the medium-temperature molten salt inlet and high-temperature water outlet of the feed water preheater through a molten salt pipeline and a water pump respectively.

[0033] Further, the feedwater preheater includes a medium-temperature molten salt inlet, a low-temperature molten salt outlet, a high-temperature water outlet, a preheater shell, a molten salt pipe and a low-temperature water inlet;

[0034] The molten salt tube is arranged in the preheater shell;

[0035] One end of the molten salt pipe is connected to the medium-temperature molten salt outlet, and the other end is connected to the low-temperature molten salt tank via a molten salt pump and valve III;

[0036] The high-temperature water outlet and the low-temperature water inlet are respectively connected to the molten salt steam generator and the condensate water tank of the multi-energy coupling power generation system.

[0037] Furthermore, the multi-energy coupling power generation system includes a water pump, a condensate tank, a steam turbine, a generator, a substation, a power grid, a cooling tower and a water pipeline;

[0038] The steam turbine, generator, substation, power grid, cooling tower and condensate tank are connected in series in sequence; the input end of the steam turbine is connected to the molten salt steam generator of the sustainable molten salt heat exchange and heat storage system via a water pump; the output end of the condensate tank is connected to the feed water preheater of the sustainable molten salt heat exchange and heat storage system via a water pump.

[0039] In a second aspect, the present invention provides an operating method of an operating system for molten salt solar thermal power generation that operates all day as described in the first aspect, comprising:

[0040] When the whole system is running, the trough solar collector field focuses light onto the molten salt pipeline to heat the low-temperature molten salt in the pipeline. The molten salt pump transports the heated high-temperature molten salt to the heat-resistant molten salt cavity of the high-temperature molten salt tank through the high-temperature molten salt transmission pipe.

[0041] The float-type liquid level sensor in the heat-resistant molten salt cavity controls the liquid level of the molten salt in the cavity, and the temperature sensor monitors the temperature in the cavity. Both sensors are connected to an external control panel for operation; the insulation board layer, the insulation rock wool board, the inner tank heat-resistant partition, the vacuum insulation layer, and the ceramic fiber insulation layer are all used for heat insulation of the heat-resistant molten salt cavity, which plays an effective role of multiple insulation; the concrete base with cooling vents makes the cavity placement more stable, while protecting the ground to prevent high temperature from causing damage to the ground; when the liquid level of the float-type liquid level sensor in the low-temperature molten salt tank reaches the set liquid level value, valves II and IV are opened, and the molten salt pump at the output end of the high-temperature molten salt tank is turned on to send the low-temperature molten salt to the electric heater for heating, and the high-temperature molten salt in the heat-resistant molten salt cavity of the high-temperature molten salt tank is passed through the high-temperature molten salt inlet to the high-temperature molten salt box of the molten salt steam generator; at this time, the multi-energy coupling power generation system starts to work;

[0042] The water pump first transports a certain amount of water originally stored in the condensate tank into the feed water preheater from the low-temperature water inlet, and then transports it from the high-temperature water outlet to the water inlet of the molten salt steam generator. After a certain period of time, the water fills the molten salt steam generator and fully exchanges heat with the high-temperature molten salt.

[0043] When the high-temperature molten salt in the high-temperature molten salt box passes through the molten salt tube with heat dissipation fins, the water in the cavity absorbs heat to cool the high-temperature molten salt in the molten salt tube. After the high-temperature molten salt in the molten salt tube is fully cooled by the water outside the tube and becomes medium-temperature molten salt, it is collected in the medium-temperature molten salt box and then passed from the medium-temperature molten salt outlet to the molten salt tube of the feed water preheater through the medium-temperature molten salt inlet; the water in the feed water preheater exchanges heat with the molten salt in the molten salt tube, and the water absorbs heat to cool the medium-temperature molten salt in the tube and become low-temperature molten salt; the low-temperature molten salt in the molten salt tube of the feed water preheater is passed through the molten salt pump and valve III to the heat-resistant molten salt cavity in the low-temperature molten salt tank;

[0044] If there is sufficient sunlight, valve I is opened, and the low-temperature molten salt in the low-temperature molten salt tank returns to the trough-type solar collector field through the low-temperature molten salt transmission pipe to absorb heat and heat up to become high-temperature liquid molten salt, forming a clockwise circulation of molten salt in the pipeline; if the solar energy is insufficient, that is, the trough-type solar collector field cannot provide enough heat for the molten salt, valve I is closed, and the high-temperature molten salt tank continues to transport high-temperature molten salt to the molten salt steam generator. The high-temperature molten salt stored in the high-temperature molten salt tank is sufficient for the system to generate electricity normally for several hours. When the molten salt in the low-temperature molten salt tank reaches the set liquid level, valves II and IV are opened, and the molten salt in the low-temperature molten salt tank is transported from the low-temperature molten salt inlet pipe to the molten salt pipe in the electric heater through the molten salt pump; the kinetic energy of the fan in the wind power generation module is transmitted to the wind power generation control component and converted into electrical energy; the electric heating wire surrounding the molten salt pipe is powered by the wind power generation control component, and the heat generated by the electric heating wire heats the low-temperature molten salt in the molten salt pipe into high-temperature molten salt and then passes to the high-temperature molten salt tank, thereby completing effective heating assistance when solar energy is insufficient to ensure sustainable operation of the system;

[0045] The water pump converts the water originally stored in the condensate tank into high-temperature steam after absorbing heat through the feed water preheater and the molten salt steam generator. The water is then transported to the steam turbine through a water pipeline to convert its internal energy into electrical energy. The water is then fully condensed into liquid water through a cooling tower and returned to the condensate tank, thus completing the clockwise pipeline cycle of steam power generation and water. The electricity generated by the generator is then supplied to our daily lives through substations and power grids. This completes the operation of the entire molten salt solar thermal power generation system that operates throughout the day.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] 1. When the sustainable molten salt heat exchange and heat storage system of the present invention is operated under insufficient light, the valve of the low-temperature molten salt pipeline is closed, and the high-temperature molten salt tank can continue to transport molten salt to the gas turbine. The high-temperature molten salt stored in the tank is sufficient for the system to generate electricity normally for several hours. When the molten salt in the low-temperature molten salt tank reaches the set liquid level, the valve of the electric heater pipeline is opened, and the low-temperature molten salt is transported to the electric heater through the molten salt pump for heating and then passed to the high-temperature molten salt tank to continue the molten salt system circulation;

[0048] 2. The electric heater of the present invention uses electricity from wind power generation, which not only improves energy utilization, but also increases power generation within a cycle. Thus, the operation of the entire molten salt solar thermal power generation system running all day is completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a structural diagram of the electric heater of the present invention;

[0050] Figure 2 is a structural diagram of a molten salt steam generator of the present invention;

[0051] Figure 3 It is a structural diagram of a feedwater preheater of the present invention;

[0052] Figure 4 It is the structural diagram of the molten salt tank of the present invention;

[0053] Figure 5 is a schematic diagram of a wind power generation module of the present invention;

[0054] Figure 6 It is a connection diagram of the molten salt solar thermal power generation system of the present invention.

[0055] In the figure: A, solar thermal collection system; B, sustainable molten salt heat exchange and storage system; C, multi-energy coupling power generation system;

[0056] A1, trough solar collector mirror field; A2, low-temperature molten salt transmission pipe; A3, high-temperature molten salt transmission pipe; B1, electric heater; B11, high-temperature molten salt outlet pipe; B12, electric heater shell; B13, electric heater molten salt pipe; B14, electric heating wire; B15, low-temperature molten salt inlet pipe; B2, high-temperature molten salt tank; B21, metal outer plate layer; B22, insulation plate layer; B23, temperature sensor; B24, control panel; B25, float type liquid level sensor; B26, refractory brick; B27, insulation rock wool board; B28, cooling vent; B29, inner tank heat-resistant partition; B210, vacuum insulation layer; B211, ceramic fiber insulation layer; B212, concrete base; B213, heat-resistant molten salt cavity; B3, molten salt pump; B4, molten salt steam generator; B41, high-temperature molten salt inlet; B42, medium-temperature molten salt outlet; B4 3. High-temperature steam outlet; B44. Steam generator shell; B45. Insulation layer; B46. Screen; B47. High-temperature molten salt box; B48. Steam generator molten salt pipe; B49. Heat dissipation fins; B410. Medium-temperature molten salt box; B411. Water inlet; B5. Feedwater preheater; B51. Medium-temperature molten salt inlet; B52. Low-temperature molten salt outlet; B53. High-temperature water outlet; B54. Preheater shell; B55 , preheater molten salt pipe; B56, low-temperature water inlet; B6, low-temperature molten salt tank; B7, valve I; B8, valve II; B9, valve III; B10, valve IV; C1, water pump; C2, condensate tank; C3, steam turbine; C4, generator; C5, substation; C6, power grid; C7, cooling tower; C8, water pipeline; C9, wind power generation module; C91, fan; C92, wind power generation control component. DETAILED DESCRIPTION

[0057] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0058] In the description of this embodiment, it should be noted that if the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this embodiment and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this embodiment.

[0059] Embodiment 1:

[0060] The present invention proposes a molten salt solar thermal power generation system that operates all day long, such as Figure 6As shown, it is mainly composed of a solar thermal collection system A, a sustainable molten salt heat exchange and storage system B, and a multi-energy coupling power generation system C. The sustainable molten salt heat exchange and storage system B acts as a bridge, connecting the solar thermal collection system A and the multi-energy coupling power generation system C in series to form the entire device.

[0061] The solar thermal system A consists of a trough collector mirror field A1, a low-temperature molten salt transmission pipe A2, and a high-temperature molten salt transmission pipe A3. The trough collector mirror field A1 is equipped with a molten salt transmission pipe, and the input and output ends are connected to the low-temperature molten salt transmission pipe A2 and the high-temperature molten salt transmission pipe A3 respectively; and through the low-temperature molten salt transmission pipe A2 and the high-temperature molten salt transmission pipe, they are connected to the low-temperature molten salt tank B6 and the high-temperature molten salt tank B2 of the sustainable molten salt heat exchange and storage system B respectively.

[0062] The sustainable molten salt heat exchange and storage system B consists of an electric heater B1, a high-temperature molten salt tank B2, a molten salt pump B3, a molten salt steam generator B4, a feed water preheater B5, a low-temperature molten salt tank B6, valves ⅠB7, ⅡB8, ⅢB9 and ⅣB10. The input end of the high-temperature molten salt tank B2 is connected to the high-temperature molten salt transmission pipe A3 and the electric heater B1, and the output end is connected to the molten salt steam generator B4; the input end of the low-temperature molten salt tank B6 is connected to the feed water preheater B5, and the output end is respectively connected to the low-temperature molten salt transmission pipe A2 and the electric heater B1; so far, the high-temperature molten salt tank B2, the electric heater B1, and the low-temperature molten salt tank B6 form a series structure; at the same time, the molten salt steam generator B4 and the feed water preheater B5 are also connected in series.

[0063] In sustainable molten salt heat exchange and storage system B, Figure 1 As shown, the electric heater B1 is composed of a high-temperature molten salt outlet pipe B11, an electric heater housing B12, a molten salt pipe B13, an electric heating wire B14 and a low-temperature molten salt inlet pipe B15. The low-temperature molten salt inlet pipe B15 and the high-temperature molten salt outlet pipe B11 are respectively located at the input end and the output end of the molten salt pipe B13; the electric heating wire B14 connected to the wind power generation control component C92 surrounds the outside of the molten salt pipe B13.

[0064] like Figure 4As shown, the high-temperature molten salt tank B2 consists of a metal outer plate layer B21, an insulation plate layer B22, a temperature sensor B23, a control panel B24, a float type liquid level sensor B25, refractory bricks B26, an insulating rock wool board B27, a cooling vent B28, an inner tank heat-resistant partition B29, a vacuum insulation layer B210, a ceramic fiber insulation layer B211 and a concrete base B212. The high-temperature molten salt tank B2 is mainly divided into upper, middle and lower parts; the upper part is a vacuum cavity between the metal outer plate layer B21 and the insulation plate layer B22; the middle part is a multi-layer surrounding cavity, which includes, from the inside to the outside, a heat-resistant molten salt cavity B213, an inner tank heat-resistant baffle B29, a vacuum insulation layer B210, a ceramic fiber insulation layer B211 and a metal outer plate layer B21; the lower part is tightly attached with refractory bricks B26 and insulation rock wool boards B27; the bottom is composed of a concrete base B212 with cooling vents B28; a temperature sensor B23 and a float-type liquid level sensor B25 are arranged in the heat-resistant molten salt cavity 213 inside the inner tank heat-resistant baffle B29, and the two sensors are monitored and controlled by an external control panel B24; the internal structure of the low-temperature molten salt tank B6 is exactly the same as that of the high-temperature molten salt tank B2.

[0065] like Figure 2 As shown, the molten salt steam generator B4 consists of a high-temperature molten salt inlet B41, a medium-temperature molten salt outlet B42, a high-temperature steam outlet B43, a steam generator shell B44, an insulation layer B45, a mesh plate B46, a high-temperature molten salt box B47, a molten salt tube B48, a heat dissipation fin B49, a medium-temperature molten salt box B410 and a water inlet B411. The steam generator shell B44 has a built-in insulation layer B45; a mesh plate 46 is provided on the upper part of the cavity; one side of the high-temperature molten salt inlet B41 is connected to the heat-resistant molten salt cavity B213 of the high-temperature molten salt tank B2 via a molten salt pump B3, and the other side is connected in sequence to the high-temperature molten salt box B47, the molten salt pipe B48, the medium-temperature molten salt box B410 to the medium-temperature molten salt outlet B42; a plurality of groups of heat dissipation fins B49 are evenly distributed on the molten salt pipe B48; the medium-temperature molten salt outlet B42 and the water inlet B411 are respectively connected to the medium-temperature molten salt inlet B51 and the high-temperature water outlet B53 of the feed water preheater B5 via a molten salt pipeline and a water pump C1.

[0066] like Figure 3 As shown, the feedwater preheater B5 is composed of a medium-temperature molten salt inlet B51, a low-temperature molten salt outlet B52, a high-temperature water outlet B53, a preheater shell B54, a molten salt pipe B55 and a low-temperature water inlet B56. One end of the molten salt pipe B55 in the preheater shell B54 is connected to the medium-temperature molten salt outlet B42, and the other end is connected to the low-temperature molten salt tank B6 through the molten salt pump B3 and the valve III B9; the high-temperature water outlet B53 and the low-temperature water inlet B56 are respectively connected to the molten salt steam generator B4 and the condensate tank C2 of the multi-energy coupling power generation system C through the water pumps C1 of their respective pipelines.

[0067] The multi-energy coupling power generation system C consists of a water pump C1, a condensate tank C2, a steam turbine C3, a generator C4, a substation C5, a power grid C6, a cooling tower C7 and a water pipeline C8. The steam turbine C3, the generator C4, the substation C5, the power grid C6, the cooling tower C7 and the condensate tank C2 are connected in series in sequence; and the input end of the steam turbine C3 is connected to the molten salt steam generator B4 of the sustainable molten salt heat exchange and heat storage system B through the water pump C1; the output end of the condensate tank C2 is connected to the feed water preheater B5 of the sustainable molten salt heat exchange and heat storage system B through the water pump C1.

[0068] Implementation principle: When the entire system is running, the trough collector mirror field A1 focuses light onto the molten salt pipeline, heating the low-temperature molten salt in the pipeline. The high-temperature molten salt pump B3 transports the heated high-temperature molten salt through the high-temperature molten salt transmission pipe A3 to the heat-resistant molten salt cavity B213 of the high-temperature molten salt tank B2.

[0069] The float type liquid level sensor B25 in the heat-resistant molten salt chamber B213 controls the liquid level height of the molten salt in the chamber, and the temperature sensor B23 monitors the temperature in the chamber. Both sensors are externally connected to the control panel B24 for control.

[0070] The insulation board layer B22, the insulating rock wool board B27, the inner tank heat-resistant partition B29, the vacuum insulation layer B210, and the ceramic fiber insulation layer B211 are all insulated by the heat-resistant molten salt cavity B213, playing an effective multiple thermal insulation role.

[0071] The concrete base B212 with cooling vents B28 allows the cavity to be placed more stably while protecting the ground and preventing damage to the ground due to high temperature.

[0072] When the liquid level of the float type liquid level sensor B25 in the low-temperature molten salt tank B6 reaches the set liquid level value, valve Ⅱ B8 and valve Ⅳ B10 are opened, and the molten salt pump B3 at the output end of the high-temperature molten salt tank B2 is turned on to send the low-temperature molten salt to the electric heater B1 for heating. The high-temperature molten salt in the heat-resistant molten salt cavity B213 of the high-temperature molten salt tank B2 is passed through the high-temperature molten salt inlet B41 to the high-temperature molten salt box B47 of the molten salt steam generator B4. At this time, the multi-energy coupling power generation system C starts to work.

[0073] The water pump C1 transports a certain amount of water originally stored in the condensate tank C2 into the feed water preheater B5 through the low-temperature water inlet B56, and then transports it to the water inlet B411 of the molten salt steam generator B4 from the high-temperature water outlet B53. After a certain period of time, the water fills the inside of the molten salt steam generator B4 and fully exchanges heat with the high-temperature molten salt.

[0074] When the high-temperature molten salt in the high-temperature molten salt box B47 passes through the molten salt tube B48 with the heat dissipation fins B49, the water in the cavity absorbs heat to cool down the high-temperature molten salt in the molten salt tube B48. After the high-temperature molten salt in the molten salt tube B48 is fully cooled down by the water outside the tube and becomes medium-temperature molten salt, it is collected in the medium-temperature molten salt box B10, and then passes from the medium-temperature molten salt outlet B42 to the molten salt tube B55 of the feed water preheater B5 through the medium-temperature molten salt inlet B51; the water in the feed water preheater B5 exchanges heat with the molten salt in the molten salt tube B55, and the water absorbs heat to cool down the medium-temperature molten salt in the tube and become low-temperature molten salt; the low-temperature molten salt in the molten salt tube B55 of the feed water preheater B5 is passed to the heat-resistant molten salt cavity in the low-temperature molten salt tank B6 through the molten salt pump B3 and valve III B9.

[0075] If there is sufficient sunlight, valve IB7 opens, and the low-temperature molten salt in the low-temperature molten salt tank B6 returns to the trough-type solar collector field A1 through the low-temperature molten salt transmission pipe A2 to absorb heat and heat up to become high-temperature liquid molten salt, forming a clockwise circulation of the molten salt in the pipeline; if the sunlight is insufficient, that is, the trough-type solar collector field A1 cannot provide enough heat for the molten salt, valve IB7 closes, and the high-temperature molten salt tank B2 continues to transport high-temperature molten salt to the molten salt steam generator B4. The high-temperature molten salt stored in the high-temperature molten salt tank is sufficient for the system to generate electricity normally for several hours. When the molten salt in the low-temperature molten salt tank reaches the set liquid level, valves IIB and IVB10 open. The molten salt in the low-temperature molten salt tank B6 is transported from the low-temperature molten salt inlet pipe B15 to the molten salt pipe B13 in the electric heater B1 through the molten salt pump B3; the kinetic energy of the fan C91 in the wind power generation module C9 is transmitted to the wind power generation control component C92 and converted into electrical energy; the electric heating wire B15 surrounds the molten salt pipe B13 and is powered by the wind power generation control component C92. The heat generated by the electric heating wire B15 heats the low-temperature molten salt in the molten salt pipe B13 into high-temperature molten salt and then passes to the high-temperature molten salt tank B2, thereby completing effective heating when solar energy is insufficient to ensure sustainable operation of the system; the wind power generation module of this embodiment is as follows Figure 5 shown.

[0076] The water pump C1 converts the water originally stored in the condensate tank C2 into high-temperature steam after double heat absorption in the feed water preheater B5 and the molten salt steam generator B4, and then transports it to the steam turbine C3 through the water pipeline C8, where the internal energy is converted into electrical energy while cooling down, and then fully condensed into liquid water through the cooling tower C7 and returned to the condensate tank C2, thus completing the clockwise pipeline cycle of steam power generation and water; the electricity generated by the generator C4 is then supplied to our daily life through the substation C5 and the power grid C6; thus, the operation of the entire molten salt solar thermal power generation system that operates all day is completed.

[0077] Embodiment 2:

[0078] This embodiment provides an operation method of an operation system of molten salt solar thermal power generation that operates all day long. Based on the operation system described in Embodiment 1, the operation method includes:

[0079] When the entire system is running, the trough collector mirror field A1 focuses light onto the molten salt pipeline, heating the low-temperature molten salt in the pipeline, and the high-temperature molten salt pump B3 transports the heated high-temperature molten salt through the high-temperature molten salt transmission pipe A3 to the heat-resistant molten salt cavity B213 of the high-temperature molten salt tank B2.

[0080] The float-type liquid level sensor B25 in the heat-resistant molten salt chamber B213 controls the molten salt liquid level in the chamber, and the temperature sensor B23 monitors the temperature in the chamber. Both sensors are connected to the external control panel B24 for operation; the insulation board layer B22, the insulation rock wool board B27, the inner tank heat-resistant partition B29, the vacuum insulation layer B210, and the ceramic fiber insulation layer B211 are all used to insulate the heat-resistant molten salt chamber B213, playing an effective role in multiple thermal insulation; the concrete base B212 with cooling vents B28 makes the chamber more stable , while protecting the ground to prevent damage to the ground caused by high temperature; when the liquid level of the float-type liquid level sensor B25 in the low-temperature molten salt tank B6 reaches the set liquid level value, valve Ⅱ B8 and valve Ⅳ B10 are opened, and the molten salt pump B3 at the output end of the high-temperature molten salt tank B2 is turned on, and the low-temperature molten salt is sent to the electric heater B1 for heating, and the high-temperature molten salt in the heat-resistant molten salt cavity B213 of the high-temperature molten salt tank B2 is passed through the high-temperature molten salt inlet B41 to the high-temperature molten salt box B47 of the molten salt steam generator B4; at this time, the multi-energy coupling power generation system (C) starts to work.

[0081] The water pump C1 transports a certain amount of water originally stored in the condensate tank C2 into the feed water preheater B5 through the low-temperature water inlet B56, and then transports it to the water inlet B411 of the molten salt steam generator B4 from the high-temperature water outlet B53. After a certain period of time, the water fills the inside of the molten salt steam generator B4 and fully exchanges heat with the high-temperature molten salt.

[0082] When the high-temperature molten salt in the high-temperature molten salt box B47 passes through the molten salt tube B48 with the heat dissipation fins B49, the water in the cavity absorbs heat to cool down the high-temperature molten salt in the molten salt tube B48. After the high-temperature molten salt in the molten salt tube B48 is fully cooled down by the water outside the tube and becomes medium-temperature molten salt, it is collected in the medium-temperature molten salt box B10, and then passes from the medium-temperature molten salt outlet B42 to the molten salt tube B55 of the feed water preheater B5 through the medium-temperature molten salt inlet B51; the water in the feed water preheater B5 exchanges heat with the molten salt in the molten salt tube B55, and the water absorbs heat to cool down the medium-temperature molten salt in the tube and become low-temperature molten salt; the low-temperature molten salt in the molten salt tube B55 of the feed water preheater B5 is passed to the heat-resistant molten salt cavity in the low-temperature molten salt tank B6 through the molten salt pump B3 and valve III B9.

[0083] If there is sufficient sunlight, valve IB7 opens, and the low-temperature molten salt in the low-temperature molten salt tank B6 returns to the trough-type solar collector field A1 through the low-temperature molten salt transmission pipe A2 to absorb heat and heat up to become high-temperature liquid molten salt, forming a clockwise circulation of the molten salt in the pipeline; if the sunlight is insufficient, that is, the trough-type solar collector field A1 cannot provide enough heat for the molten salt, valve IB7 closes, and the high-temperature molten salt tank B2 continues to transport high-temperature molten salt to the molten salt steam generator B4. The high-temperature molten salt stored in the high-temperature molten salt tank is sufficient for the system to generate electricity normally for several hours. When the molten salt in the low-temperature molten salt tank reaches the set liquid level, valves IIB and valve IV B10 is turned on, and the molten salt in the low-temperature molten salt tank B6 is transported from the low-temperature molten salt inlet pipe B15 to the molten salt pipe B13 in the electric heater B1 through the molten salt pump B3; the kinetic energy of the fan C91 in the wind power generation module C9 is transmitted to the wind power generation control component C92 and converted into electrical energy; the electric heating wire B15 surrounding the molten salt pipe B13 is powered by the wind power generation control component C92, and the heat generated by the electric heating wire B15 heats the low-temperature molten salt in the molten salt pipe B13 into high-temperature molten salt and then passes to the high-temperature molten salt tank B2, thereby completing effective heating when solar energy is insufficient and ensuring sustainable system operation.

[0084] The water pump C1 converts the water originally stored in the condensate tank C2 into high-temperature steam after double heat absorption in the feed water preheater B5 and the molten salt steam generator B4, and then transports it to the steam turbine C3 through the water pipeline C8, where the internal energy is converted into electrical energy while cooling down, and then fully condensed into liquid water through the cooling tower C7 and returned to the condensate tank C2, thus completing the clockwise pipeline cycle of steam power generation and water; the electricity generated by the generator C4 is then supplied to our daily life through the substation C5 and the power grid C6; thus, the operation of the entire molten salt solar thermal power generation system that operates all day is completed.

[0085] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features, and in the description of the present invention, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0086] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0087] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0088] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0089] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A molten salt solar thermal power generation system that operates all day, characterized in that: It includes solar thermal collection system (A), sustainable molten salt heat exchange and storage system (B), and multi-energy coupling power generation system (C); The sustainable molten salt heat exchange and heat storage system (B) is respectively connected to the solar thermal collection system (A) and the multi-energy coupling power generation system (C); The solar thermal collection system (A) comprises a trough-type thermal collection mirror field (A1), a low-temperature molten salt transmission pipe (A2), and a high-temperature molten salt transmission pipe (A3); the sustainable molten salt heat exchange and heat storage system (B) comprises a low-temperature molten salt tank (B6) and a high-temperature molten salt tank (B2); The trough-type solar collector field (A1) is equipped with a molten salt transmission pipe, the input end and the output end of which are respectively connected to a low-temperature molten salt transmission pipe (A2) and a high-temperature molten salt transmission pipe (A3); and the low-temperature molten salt transmission pipe (A2) and the high-temperature molten salt transmission pipe (A3) are respectively connected to a low-temperature molten salt tank (B6) and a high-temperature molten salt tank (B2) of the sustainable molten salt heat exchange and heat storage system (B) through the low-temperature molten salt transmission pipe (A2) and the high-temperature molten salt transmission pipe (A3); The sustainable molten salt heat exchange and heat storage system (B) comprises an electric heater (B1), a high-temperature molten salt tank (B2), a molten salt pump (B3), a molten salt steam generator (B4), a feed water preheater (B5), a low-temperature molten salt tank (B6), a valve I (B7), a valve II (B8), a valve III (B9) and a valve IV (B10); The input end of the high-temperature molten salt tank (B2) is respectively connected to the electric heater (B1) and the high-temperature molten salt transmission pipe (A3), and the output end of the high-temperature molten salt tank (B2) is connected to the molten salt steam generator (B4); The input end of the low-temperature molten salt tank (B6) is connected to the feed water preheater (B5), and the output end is respectively connected to the electric heater (B1) and the low-temperature molten salt transmission pipe (A2); The high-temperature molten salt tank (B2), the electric heater (B1), and the low-temperature molten salt tank (B6) form a series structure; the molten salt steam generator (B4) and the feed water preheater (B5) are connected in series; The molten salt pump (B3) is arranged in the sustainable molten salt heat exchange and heat storage system (B) to provide pumping force for the molten salt; The valve I (B7) is arranged between the low-temperature molten salt transmission pipe (A2) and the low-temperature molten salt tank (B6), and is used to control the input of the low-temperature molten salt to the trough-type solar collector field (A1), and is opened when the sunlight is sufficient, and closed when the sunlight is insufficient; The valve II (B8) is arranged between the electric heater (B1) and the low-temperature molten salt tank (B6) to control the input of the low-temperature molten salt to the electric heater (B1), and is opened when the molten salt in the low-temperature molten salt tank (B6) reaches a set liquid level, and is closed when there is sufficient light; The valve III (B9) is arranged between the feed water preheater (B5) and the low temperature molten salt tank (B6) and is used to control the input of the low temperature molten salt into the low temperature molten salt tank (B6); The valve IV (B10) is arranged between the electric heater (B1) and the high-temperature molten salt tank (B2) to control the flow of the heated molten salt into the high-temperature molten salt tank (B2), opens when the molten salt in the low-temperature molten salt tank (B6) reaches a set liquid level, and closes when there is sufficient light; The electric heater (B1) comprises a high-temperature molten salt outlet pipe (B11), an electric heater shell (B12), an electric heater molten salt pipe (B13), an electric heating wire (B14) and a low-temperature molten salt inlet pipe (B15); The low-temperature molten salt inlet pipe (B15) and the high-temperature molten salt outlet pipe (B11) are respectively located at the input end and the output end of the electric heater molten salt pipe (B13); the electric heating wire (B14) connected to the wind power generation control component (C92) surrounds the outside of the electric heater molten salt pipe (B13); The high-temperature molten salt tank (B2) includes a metal outer plate layer (B21), a thermal insulation plate layer (B22), a temperature sensor (B23), a control panel (B24), a float type liquid level sensor (B25), refractory bricks (B26), thermal insulation rock wool boards (B27), cooling vents (B28), an inner tank heat-resistant baffle (B29), a vacuum insulation layer (B210), a ceramic fiber thermal insulation layer (B211) and a concrete base (B212); The high-temperature molten salt tank (B2) is divided into upper, middle and lower parts; the upper part is a vacuum cavity between the metal outer plate layer (B21) and the insulation plate layer (B22); the middle part is a multi-layer surrounding cavity, which includes, from inside to outside, a heat-resistant molten salt cavity (B213), an inner tank heat-resistant baffle (B29), a vacuum insulation layer (B210), a ceramic fiber insulation layer (B211), and a metal outer plate layer (B21); the lower part is closely attached with refractory bricks (B26) and insulation rock wool boards (B27); the bottom is a concrete base (B212) with cooling vents (B28); A temperature sensor (B23) and a float type liquid level sensor (B25) are provided in the heat resistant molten salt chamber (B213) inside the heat resistant baffle (B29) of the inner tank, and are connected to an external control panel (B24) to monitor and control the two sensors; The internal structure of the low-temperature molten salt tank (B6) is exactly the same as that of the high-temperature molten salt tank (B2).

2. The operating system of molten salt solar thermal power generation that operates all day according to claim 1 is characterized in that: There are multiple molten salt pumps (B3), which are respectively installed between the high-temperature molten salt transmission pipe (A3) and the high-temperature molten salt tank (B2), between the high-temperature molten salt tank (B2) and the molten salt steam generator (B4), between the electric heater (B1) and the low-temperature molten salt tank (B6), between the low-temperature molten salt tank (B6) and the low-temperature molten salt transmission pipe (A2), and between the low-temperature molten salt tank (B6) and the feed water preheater (B5).

3. The operating system of molten salt solar thermal power generation that operates all day according to claim 1 is characterized in that: The molten salt steam generator (B4) comprises a high-temperature molten salt inlet (B41), a medium-temperature molten salt outlet (B42), a high-temperature steam outlet (B43), a steam generator shell (B44), an insulation layer (B45), a mesh plate (B46), a high-temperature molten salt box (B47), a steam generator molten salt pipe (B48), a heat dissipation fin (B49), a medium-temperature molten salt box (B410) and a water inlet (B411); The heat-insulating layer (B45) is built into the steam generator shell (B44); a mesh plate (B46) is provided on the upper part of the inner cavity of the steam generator shell (B44); One side of the high-temperature molten salt inlet (B41) is connected to the heat-resistant molten salt chamber (B213) of the high-temperature molten salt tank (B2) via a molten salt pump (B3), and the other side is sequentially connected to the high-temperature molten salt box (B47), the steam generator molten salt pipe (B48), the medium-temperature molten salt box (B410) to the medium-temperature molten salt outlet (B42); A plurality of groups of heat dissipation fins (B49) are evenly distributed on the steam generator molten salt tube (B48); The medium-temperature molten salt outlet (B42) and water inlet (B411) are connected to the medium-temperature molten salt inlet (B51) and high-temperature water outlet (B53) of the feed water preheater (B5) via the steam generator molten salt pipe (B48) and the water pump (C1) respectively.

4. The operating system of molten salt solar thermal power generation that operates all day according to claim 1 is characterized in that: The feedwater preheater (B5) comprises a medium-temperature molten salt inlet (B51), a low-temperature molten salt outlet (B52), a high-temperature water outlet (B53), a preheater shell (B54), a preheater molten salt pipe (B55) and a low-temperature water inlet (B56); The preheater molten salt tube (B55) is arranged in the preheater shell (B54); One end of the preheater molten salt pipe (B55) is connected to the medium-temperature molten salt outlet (B42), and the other end is connected to the low-temperature molten salt tank (B6) via a molten salt pump (B3) and a valve III (B9); The high-temperature water outlet (B53) and the low-temperature water inlet (B56) are respectively connected to the molten salt steam generator (B4) and the condensate tank (C2) of the multi-energy coupling power generation system (C).

5. The operating system of molten salt solar thermal power generation that operates all day according to claim 1 is characterized in that: The multi-energy coupling power generation system (C) comprises a water pump (C1), a condensate tank (C2), a steam turbine (C3), a generator (C4), a transformer substation (C5), a power grid (C6), a cooling tower (C7) and a water pipeline (C8); The steam turbine (C3), generator (C4), transformer substation (C5), power grid (C6), cooling tower (C7), and condensate tank (C2) are connected in series in sequence; and the input end of the steam turbine (C3) is connected to the molten salt steam generator (B4) of the sustainable molten salt heat exchange and heat storage system (B) via a water pump (C1); the output end of the condensate tank (C2) is connected to the feed water preheater (B5) of the sustainable molten salt heat exchange and heat storage system (B) via a water pump (C1).

6. A method for operating a molten salt solar thermal power generation system that operates all day as claimed in any one of claims 1 to 5, comprising: When the entire system is running, the trough-type solar collector field (A1) is used to focus light onto the molten salt pipeline to heat the low-temperature molten salt in the pipeline. The molten salt pump (B3) transports the heated high-temperature molten salt through the high-temperature molten salt transmission pipe (A3) to the heat-resistant molten salt chamber (B213) of the high-temperature molten salt tank (B2).

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