Molten salt tank and molten salt energy storage device

Abstract

The utility model discloses a fused salt tank and a fused salt energy storage device in the field of fused salt energy storage devices, which comprise a tank body and a fused salt pump, the tank body is horizontally arranged, the inner bottom of one side of the tank body protrudes downwards to be provided with a groove, the upper end of the other side of the tank body is provided with a fused salt inlet pipe used for being connected with equipment, the fused salt pump is provided with a suction inlet and an outlet pipe, and the suction inlet is communicated with the outlet pipe. And the suction inlet is formed in the groove. According to the molten salt tank provided by the utility model, the groove is formed in the bottom in the tank body, and the molten salt pump suction inlet is formed in the groove, so that all molten salt in the tank body can be pumped out for use, and the utilization rate of the molten salt is improved. The molten salt pump used in the horizontal molten salt tank has the advantages of being short in pump shaft length, small in vibration, simple in structure, mature in technology and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to molten salt energy storage device field especially relates to a molten salt tank and molten salt energy storage device. BACKGROUND

[0002] In recent years with the vigorous promotion of renewable energy, due to the significant volatility and intermittency of new energy, the problem of curtailment of wind and light has occurred, a large number of photovoltaic power stations are forced to 'bask in the sun', and wind turbine generators'sigh at the sight of wind', and some new energy construction in serious curtailment areas has been stalled, which seriously restricts the development of new energy in China.

[0003] Molten salt energy storage is a kind of efficient energy storage mode, which uses molten salt as heat storage medium to store energy in the form of heat in the process of molten salt temperature rise. Molten salt energy storage generally adopts a double-tank scheme, which configures a low-temperature molten salt tank and a high-temperature molten salt tank. Molten salt, as a heat storage medium, flows between the high- and low-temperature storage tanks to realize heat storage and release functions. It can provide stable heat energy supply during the peak period of energy demand, especially showing great potential in solving the problem of curtailment of wind and light. In recent years, molten salt energy storage has been increasingly widely used in solar thermal power stations, thermal power flexibility reconstruction and industrial and commercial energy storage projects.

[0004] The existing molten salt tank is large in size and vertically arranged, and a long molten salt pump needs to be arranged inside. The long molten salt pump is high in cost and low in durability, and when pumping molten salt at the bottom, a large pumping power is required. Therefore, some molten salt pumps are not completely arranged at the bottom of the molten salt tank, so the utilization rate of molten salt is low, and the vertically arranged molten salt tank needs a higher stable installation support, increasing the cost. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a molten salt tank and molten salt energy storage device to improve the utilization rate of molten salt and use a molten salt pump with lower power and shaft length.

[0006] To solve the above technical problems, the following technical scheme is adopted:

[0007] In the first aspect, the utility model provides a molten salt tank, the tank body is horizontally arranged, the inner bottom of one side of the tank body is downwardly protrudingly provided with a groove, the other side end is provided with a molten salt inlet pipe for being connected with equipment, a suction inlet and an outlet pipe are arranged on the molten salt pump, and the suction inlet is arranged in the groove.

[0008] Optionally, at least two supports are arranged on the outer bottom of the tank body.

[0009] Optionally, a connecting pipe is arranged on the tank body above the groove, the outer end of the connecting pipe is connected with one end of a bellows expansion joint, the other end of the bellows expansion joint is connected with a flange of the molten salt pump, and the flange of the molten salt pump is supported on an independent support platform.

[0010] In a second aspect, the utility model provides a kind of molten salt energy storage device, including the molten salt tank of any one of first aspect, first pipeline, second pipeline, steam generator, molten salt heater and control system, several the molten salt tank is arranged in parallel, the molten salt tank is filled with molten salt, the molten salt pump is started and stopped by the control system control, the molten salt heater and the steam generator are started and stopped by the control system control;

[0011] The outlet pipe on the molten salt tank is connected with the first pipeline, the molten salt inlet pipe is connected with the second pipeline, the molten salt inlet pipe of the steam generator and the molten salt inlet pipe of the molten salt heater are connected with the first pipeline, and the output end of the steam generator and the output end of the molten salt generator are connected with the second pipeline.

[0012] Optionally, the molten salt tank has at least one empty molten salt tank that is not filled with molten salt.

[0013] Optionally, a check valve is provided on the outlet pipe, and a molten salt stop valve is provided on the molten salt inlet pipe, and the molten salt stop valve is controlled to be on or off by the control system.

[0014] Optionally, a stop valve is provided on the molten salt inlet pipe of the steam generator and the molten salt inlet pipe of the molten salt heater, and the stop valve is controlled to be on or off by the control system.

[0015] Optionally, the steam generator is provided with a feedwater system and a steam delivery system.

[0016] Compared with the prior art, the utility model has the beneficial effects that:

[0017] 1. The molten salt tank provided by the utility model has a groove in the bottom of the tank body, and a molten salt pump suction inlet is arranged in the groove. The molten salt in the tank body can be completely pumped out for use, thereby improving the utilization rate of molten salt. The molten salt pump used in the horizontal molten salt tank has the advantages of short pump shaft length, small vibration, simple structure, and mature technology.

[0018] 2. The molten salt energy storage device provided by the utility model uses an external molten salt heater to heat the molten salt, so that the molten salt is uniformly heated. The molten salt tank is also connected with a steam generator. When the molten salt releases energy, it enters the steam generator for heat exchange. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structure schematic view of a molten salt tank in an embodiment of the utility model;

[0020] Figure 2 is a structure schematic view of a molten salt energy storage device in an embodiment of the utility model.

[0021] REFERENCE SIGNS

[0022] 1. Molten salt tank; 2. Tank body; 3. Molten salt pump; 4. Inlet; 5. Outlet pipe; 6. Impeller; 7. Groove; 8. Support; 9. Connecting pipe; 901. Bellows expansion joint; 902. Support platform; 10. Molten salt inlet pipe; 11. Empty molten salt tank; 12. First pipeline; 13. Second pipeline; 14. Steam generator; 15. Molten salt heater; 16. Check valve; 17. Molten salt shut-off valve; 18. Steam shut-off valve; 19. Heating shut-off valve. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use.

[0024] Example 1

[0025] like Figure 1 As shown, this embodiment provides a molten salt tank 1, including a tank body 2 and a molten salt pump 3. The tank body 2 is arranged horizontally. A groove 7 protrudes downward from the bottom of one side of the tank body 2, and a molten salt inlet pipe 10 for connecting to equipment is provided at the other end. The molten salt pump 3 is provided with a suction port 4 and an outlet pipe 5. The suction port 4 extends into the tank body 2 and is located in the groove 7. An impeller 6 is provided on the suction port located in the groove 7. The impeller 6 is driven to rotate by the molten salt pump 3.

[0026] Tank 2 is cylindrical, with a diameter not exceeding 5 meters and a length not exceeding 60 meters. It can be manufactured in the factory and installed after being transported to the project site. Compared with the large tank 2, its manufacturing is not affected by weather conditions, which can fully guarantee product quality.

[0027] An internal groove 7 is formed by extending outward from the bottom of the tank body 2. The groove 7 is used to place the suction port 4 and the impeller 6. As the impeller 6 rotates, a negative pressure is generated at the center of the impeller 6, and the surrounding molten salt is sucked into the suction port 4 for delivery. The groove 7 is the lowest position inside the tank body 2, which can suck out the molten salt in the tank body 2 for use.

[0028] The horizontally arranged tank 2 has a molten salt pump shaft length close to its diameter, eliminating the need for a long pump shaft. The molten salt pump 3 can completely extract and utilize the molten salt in the tank 2 with relatively low power, which improves the durability of the molten salt pump 3, increases the utilization rate of molten salt, and reduces power costs.

[0029] The horizontally arranged tank 2 is more stable and less affected by the external environment, and does not require a complex structural support.

[0030] Embodiment Two

[0031] This embodiment is based on embodiment 1 to provide a molten salt tank 1, the difference being that:

[0032] The outer bottom of the tank 2 is provided with two supports 8, which support and install the tank 2. The two supports 8 are both arranged on the outer bottom of the tank 2 near the two ends.

[0033] A connecting pipe 9 is arranged directly above the groove 7 of the tank 2. One end of the connecting pipe 9 is in communication with the inside of the tank 2, and the other end is connected with a corrugated pipe expansion joint 901. The other end of the corrugated pipe expansion joint 901 is connected with the flange of a molten salt pump. The flange of the molten salt pump is supported on a separate support platform 902, which is used to set the molten salt pump 3. The weight of the molten salt pump 3 is entirely borne by the support platform 902. The molten salt pump 3 is connected with a suction inlet 4 and an outlet pipe 5. The suction inlet 4 is located in the groove 7, and an impeller 6 is further arranged on the suction inlet 4. The impeller 6 is driven by the motor in the molten salt pump 3 through a transmission shaft, which is located in the suction inlet 4.

[0034] In some embodiments, the impeller 6 can be directly below the suction inlet 4. After entering the suction inlet 4, the molten salt is pumped into the outlet pipe 5 by the molten salt pump 3 through the rotation of the impeller 6. The impeller 6 can also be directly above the suction inlet 4. At this time, the rotation direction of the impeller 6 is opposite to that when the impeller 6 is placed below the suction inlet 4. Through the rotation of the impeller 6, a negative pressure is formed at the center of the impeller 6 to suck in the molten salt.

[0035] In use, the molten salt tank 1 is filled with molten salt medium, and the molten salt pump 3 is turned on. After the molten salt pump 3 is turned on, the end impeller 6 also rotates, and the internal molten salt enters the suction inlet 4 from the suction inlet. Subsequently, the molten salt enters the equipment through the outlet pipe 5. The used molten salt enters the molten salt tank 1 again through the molten salt inlet pipe 10.

[0036] Embodiment Three

[0037] This embodiment provides a molten salt energy storage device, which comprises the molten salt tank 1 provided in embodiment 1 or embodiment 2. A plurality of molten salt tanks 1 are arranged in parallel, and the molten salt tanks 1 are filled with molten salt. The device further comprises a first pipeline 12, a second pipeline 13, a steam generator 14, a molten salt heater 15, and a control system. The control system controls the start and stop of the molten salt pump 3 on the molten salt tank 1, thereby controlling the start and stop of the molten salt delivery.

[0038] As Figure 1 , Figure 2As shown, the outlet pipe 5 of the molten salt pump 3 is connected to the first pipe 12, the molten salt inlet pipe 10 is connected to the second pipe 13, the molten salt inlet pipe of the steam generator 14 and the molten salt inlet pipe of the molten salt heater 15 are both connected to the first pipe 12, and the output end of the steam generator 14 and the output end of the molten salt generator are both connected to the second pipe 13.

[0039] During the release of molten salt energy, the molten salt in the molten salt tank 1 is transported to the steam generator 14 through the first pipe 12 for heat exchange, and then the released molten salt is transported back to the molten salt tank 1 through the second pipe 13.

[0040] During molten salt energy storage, molten salt is transported to the molten salt generator through the first pipe 12 to heat the molten salt. The heated molten salt is then transported to the molten salt tank 1 for storage through the second pipe 13.

[0041] Example 4

[0042] This embodiment provides a molten salt energy storage device based on Embodiment 3, the difference being that: among the several molten salt tanks 1, there is an empty molten salt tank 11 that is not filled with molten salt. During the molten salt energy release process, the molten salt that has undergone heat exchange with the steam generator 14 becomes low-temperature molten salt, which is discharged into the empty molten salt tank 11 through the second pipe 13. After the empty molten salt tank 11 is filled, the original molten salt tank 1 becomes an empty molten salt tank 11.

[0043] like Figure 1 As shown, a check valve 16 is also provided on the outlet pipe 5, which is connected to the first pipe 12. The check valve 16 can prevent the molten salt in the outlet pipe 5 from flowing back into the tank 2. A molten salt shut-off valve 17 is provided on the molten salt inlet pipe 10, which is connected to the second pipe 13. The molten salt shut-off valve 17 is controlled by the control system. When the steam generator 14 or the molten salt heater 15 starts to work, the molten salt shut-off valve 17 corresponding to the empty molten salt tank 11 is opened, and the molten salt generated by the steam generator 14 or the molten salt heater 15 is discharged into the empty molten salt tank 11.

[0044] A steam shut-off valve 18 is installed on the molten salt inlet pipe of the steam generator 14, and a heating shut-off valve 19 is installed on the molten salt inlet pipe of the molten salt heater 15. Both the steam shut-off valve 18 and the heating shut-off valve 19 are controlled by a control system. The molten salt inlet pipes of the molten salt heater 15 and the steam generator 14 are both connected to the first pipe 12, and their output ends are both connected to the second pipe 13. The molten salt inlet pipe 10 on each tank 2 is connected to the second pipe 13.

[0045] The control system comprises a controller and a molten salt tank 1 database, the molten salt tank 1 database comprises a low-temperature molten salt corresponding molten salt tank 1 number, a high-temperature molten salt corresponding molten salt tank 1 number and an empty molten salt tank 1 number, the controller receives a working signal of the steam generator 14 and the molten salt heater 15 to control the start and stop of the corresponding stop valve and the molten salt pump 3. The controller model can be SPC-STW-S0402CTR.

[0046] Specifically, when the controller receives the opening working signal of the steam generator 14, the molten salt pump 3 corresponding to one of the high-temperature molten salt in the molten salt tank 1 database and the molten salt stop valve 17 corresponding to the empty molten salt tank 11 are opened, and the steam stop valve 18 is opened, the high-temperature molten salt is pumped into the steam generator 14 by the molten salt pump 3 for heat exchange, and the high-temperature molten salt becomes low-temperature molten salt, which is transported to the empty molten salt tank 11 through the second pipeline 13, until the molten salt in the high-temperature molten salt tank 1 is used up, the next high-temperature molten salt corresponding molten salt pump 3 is opened, until the controller receives the stop working signal of the steam generator 14, the corresponding molten salt pump 3 and stop valve are closed.

[0047] When the control system controls the steam generator 14 to work according to the demand of the steam, the steam stop valve 18 is opened, the heating stop valve 19 is closed, and the molten salt pump 3 of one of the molten salt tanks 1 containing high-temperature molten salt is controlled to work, the molten salt stop valve 17 corresponding to the empty molten salt tank 11 is opened, and the high-temperature molten salt is transported to the steam generator 14 by the molten salt pump 3 for heat exchange, and the heat-exchanged molten salt is transported to the empty molten salt tank 11.

[0048] The driving power supply of the molten salt heater 15 can be one of grid power supply, wind power supply, photovoltaic power supply or other new energy, which drives the molten salt heater 15 to heat the molten salt and convert the energy into heat energy stored in the molten salt. The steam generator 14 is connected with a feedwater system and a steam system, and after heat exchange in the steam generator 14, the water becomes water vapor which is discharged through the steam system for use or energy conversion.

[0049] In some embodiments, there are two empty molten salt tanks 11, two first pipes 12 and two second pipes 13, one first pipe 12 is connected to the outlet pipe 5 at one end and to the molten salt inlet pipe of the steam generator 14 at the other end; one first pipe 12 is connected to the outlet pipe 5 at one end and to the molten salt inlet pipe of the molten salt generator at the other end; one second pipe 13 is connected to the output end of the steam generator 14 at one end and to the molten salt inlet pipe 10 at the other end; one second pipe 13 is connected to the output end of the molten salt generator at one end and to the molten salt inlet pipe 10 at the other end. The passage between the steam generator 14 and the molten salt heater 15 is separated, the molten salt heater 15 works simultaneously with the steam generator 14, and the two empty molten salt tanks 11 respectively receive the molten salt from the steam generator 14 and the molten salt in the molten salt heater 15.

[0050] In some embodiments, the molten salt heater 15 and the steam generator 14 are arranged above a row of molten salt tanks 1, and the molten salt after the reaction of the molten salt heater 15 and the steam generator 14 flows into the empty molten salt tank 11 by gravity, and flows into the designated empty molten salt tank 11 through the on-off of the molten salt stop valve 17.

[0051] In use, the low-temperature molten salt in the molten salt tank is pumped by the molten salt pump and delivered to the molten salt heater through the first pipe for heating;

[0052] The high-temperature molten salt after heating is delivered to the empty molten salt tank through the second pipe, and after the molten salt in the molten salt tank is completely heated, the empty molten salt tank contains high-temperature molten salt; the molten salt tank that originally outputs low-temperature molten salt becomes an empty molten salt tank, and the molten salt in the next low-temperature molten salt tank continues to be heated and delivered to the empty molten salt tank, until the molten salt in the molten salt tank is all high-temperature molten salt, and the energy storage is completed.

[0053] The high-temperature molten salt in the molten salt tank is pumped by the molten salt pump and delivered to the steam generator through the first pipe for heat release;

[0054] The molten salt after heat release is delivered to the empty molten salt tank through the second pipe, and after the molten salt in the molten salt tank is completely released, the empty molten salt tank contains low-temperature molten salt; the molten salt tank that originally outputs high-temperature molten salt becomes an empty molten salt tank, and the molten salt in the next high-temperature molten salt tank continues to be released and delivered to the empty molten salt tank, until the molten salt in the molten salt tank is all low-temperature molten salt, and the heat release is completed.

[0055] In the description of the utility model, need understanding is, the term "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and so on indicate the orientation or positional relation based on the orientation or positional relation shown in the drawing, just for the convenience of describing the utility model and simplifying the description, and not indicate or imply that the indicated device or element must have a particular orientation, construct and operate in a particular orientation, therefore can not be understood as the limitation to the utility model. In addition, the term "first", "second" and so on are only for the purpose of description, and can not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" and so on can explicitly or implicitly include one or more features. In the description of the utility model, unless otherwise specified, the meaning of "a plurality of" is two or more than two. In the description of the utility model, it should be pointed out that, unless otherwise specified and limited, the term "mounting", "connection", "connection" should be understood broadly, for example, can be fixedly connected, can also be detachably connected, or integrally connected, can be mechanically connected, can also be electrically connected, can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above-mentioned terms in the utility model can be understood through specific circumstances.

[0056] The above is only the preferred embodiment of the utility model, it should be pointed out that, for ordinary skilled in the art, on the premise of not departing from the technical principles of the utility model, can also make a number of improvements and deformations, these improvements and deformations also should be regarded as the protection scope of the utility model.

Claims

1. A molten salt tank comprising a tank body and a molten salt pump, characterized in that, The tank body is horizontally arranged, the inner bottom of one side of the tank body is provided with a groove protruding downward, the other side end is provided with a molten salt inlet pipe for connecting with the equipment, the molten salt pump is provided with a suction inlet and an outlet pipe, and the suction inlet is arranged in the groove.

2. The molten salt tank of claim 1, wherein, The outer bottom of the tank body is provided with at least two supports.

3. The molten salt tank of claim 1, wherein, A connecting pipe is arranged on the tank body above the groove, the outer end of the connecting pipe is connected with one end of a bellows expansion joint, the other end of the bellows expansion joint is connected with a flange of the molten salt pump, and the flange of the molten salt pump is supported on a separate support platform.

4. A molten salt energy storage device, characterized by, The molten salt tank comprises a first pipe, a second pipe, a steam generator, a molten salt heater and a control system, a plurality of the molten salt tanks are arranged in parallel, the molten salt tanks are filled with molten salt, the molten salt pump is controlled to start and stop by the control system, and the molten salt heater and the steam generator are controlled to start and stop by the control system. The outlet pipe on the molten salt tank is connected with the first pipe, the molten salt inlet pipe is connected with the second pipe, the molten salt inlet pipe of the steam generator and the molten salt inlet pipe of the molten salt heater are connected with the first pipe, and the output end of the steam generator and the output end of the molten salt generator are connected with the second pipe.

5. The molten salt energy storage device of claim 4, wherein, The molten salt tank is at least one empty molten salt tank without filling molten salt.

6. The molten salt energy storage device of claim 4, wherein, A check valve is arranged on the outlet pipe, a molten salt stop valve is arranged on the molten salt inlet pipe, and the molten salt stop valve is controlled to be opened and closed by the control system.

7. The molten salt energy storage device of claim 4, wherein, A stop valve is arranged on the molten salt inlet pipe of the steam generator and the molten salt inlet pipe of the molten salt heater, and the stop valve is controlled to be opened and closed by the control system.

8. The molten salt energy storage device of claim 4, wherein, The steam generator is provided with a feedwater system and a steam delivery system.

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