Molten salt system with heat recovery function

Abstract

The utility model discloses a fused salt system with a heat recovery function, which relates to the field of fused salt storage equipment and comprises a cold salt tank, a hot salt tank and a heat exchanger, the cold salt tank and the hot salt tank are communicated through a fused salt pump to realize fused salt conveying, and the heat exchanger is arranged in the cold salt tank and contacted with fused salt. A first scavenging port of the heat exchanger is located in the cold salt tank and extends out of the molten salt liquid level of the cold salt tank, a second scavenging port of the heat exchanger extends out of the cold salt tank and enters the hot salt tank, and the second scavenging port of the heat exchanger is located above the molten salt liquid level in the hot salt tank. In the heat storage process, the cold salt tank is used for conducting heat recovery on high-temperature waste gas exhausted from the hot salt tank, the heat utilization efficiency is improved, heat loss is reduced, energy consumption is reduced, in the heat release process, the high-temperature waste gas exhausted from the cold salt tank is used for supplementing the hot salt tank, direct emission of the high-temperature waste gas and suction of cold air are reduced, and the heat storage efficiency is improved. And heat loss and energy consumption are reduced.

Description

Technical Field

[0001] The utility model relates to the field of molten salt storage equipment, in particular to a molten salt system with a heat recovery function. Background Technique

[0002] A molten salt system generally consists of a molten salt storage tank, a molten salt heating system, and a molten salt heat release system. Generally, the molten salt is heated to store heat during the low-energy-consumption period and releases heat during the high-energy-consumption period to achieve peak shaving and valley filling.

[0003] During the heat storage process, the molten salt flows from the cold salt tank to the hot salt tank. High-temperature gas is discharged from the hot salt tank, and cold air is inhaled from the air into the cold salt tank. During the heat release process, the molten salt flows from the hot salt tank to the cold salt tank. Medium-temperature gas is discharged from the cold salt tank, and cold air is inhaled from the air into the hot salt tank. That is, in each heat storage and release cycle, the cold and hot salt tanks respectively inhale cold air once and discharge high- and medium-temperature waste gas once. It is equivalent to that the cold and hot salt tanks inhale cold air once in each cycle and heat it into high- and medium-temperature waste gas, and then discharge it to the atmosphere.

[0004] To ensure fluidity, the molten salt in the molten salt system is in a liquid state. Even the molten salt in the cold salt tank needs to maintain a certain temperature, and the molten salt in the hot salt tank needs to accumulate heat to ensure sufficient energy can be provided during heat release. Therefore, the temperature of the gas discharged from the cold and hot salt pipes is very high, and the directly discharged heat cannot be recovered. Moreover, the cold air entering after discharge needs to be heated, which consumes energy, resulting in double waste. At the same time, there is a certain amount of molten salt vapor in the above high-temperature exhaust gas, resulting in molten salt material loss. And the molten salt discharged to the surrounding factory area dissolves in the humid environment, which will cause corrosion of equipment or structures and reduce their service life. Content of the Utility Model

[0005] The purpose of the utility model is to provide a molten salt system with a heat recovery function to solve the problems existing in the above-mentioned prior art. During the heat storage process, the high-temperature waste gas discharged from the hot salt tank is used to heat the cold salt tank to prevent the molten salt in the cold salt tank from solidifying due to temperature drop. During the heat release process, the high-temperature waste gas discharged from the cold salt tank is used to heat the hot salt tank to maintain the high-temperature state in the hot salt tank.

[0006] To achieve the above purpose, the utility model provides the following solution:

[0007] The utility model provides a molten salt system with a heat recovery function, including a cold salt tank, a hot salt tank, and a heat exchanger. The cold salt tank and the hot salt tank are connected through a molten salt pump to realize molten salt transportation;

[0008] The heat exchanger is arranged in the cold salt tank and contacts with the molten salt. The first air exchange port of the heat exchanger is located inside the cold salt tank and extends out of the molten salt liquid level of the cold salt tank. The second air exchange port of the heat exchanger extends out of the cold salt tank and enters the hot salt tank, and the second air exchange port of the heat exchanger is above the molten salt liquid level in the hot salt tank.

[0009] Preferably, the main body of the heat exchanger is a heat exchange tube. The first air exchange port of the heat exchanger is connected to the heat exchange tube through a breather tube inside the tank, and the second air exchange port of the heat exchanger is connected to the heat exchange tube through a connecting tube between the cold and hot tanks.

[0010] Preferably, the heat exchange tube is a coil tube, and the coil tube is arranged at the bottom of the cold salt tank.

[0011] Preferably, a molten salt condensation device is further included. The molten salt condensation device and the cold salt tank are communicated through a breather tube of the cold salt tank;

[0012] The molten salt condensation device includes a tank body. An exhaust inlet from the cold salt tank, an exhaust port, a cooling medium inlet, and a liquid discharge port are arranged on the tank body. The cold salt tank unidirectionally conveys high-temperature gas to the molten salt condensation device. A molten salt gas release device is arranged inside the tank body. The molten salt gas release device is communicated with the exhaust inlet from the cold salt tank, and a cooling medium release device is communicated with the cooling medium inlet. The high-temperature gas discharged from the cold salt tank is mixed and cooled with the cooling medium in the molten salt condensation device.

[0013] Preferably, the cooling medium inlet is a water inlet, and a liquid level gauge is further arranged inside the tank body. The liquid level gauge includes a high liquid level gauge and a low liquid level gauge;

[0014] The molten salt gas release device includes a molten salt gas spray pipe communicated with the exhaust inlet from the cold salt tank. A molten salt gas spray head is arranged on the molten salt gas spray pipe. The position of the molten salt gas spray pipe is lower than the horizontal plane where the measurement high position of the liquid level gauge is located.

[0015] Preferably, the cooling medium release device is a spray pipe, and the spray pipe is higher than the molten salt gas spray pipe.

[0016] Preferably, a partition type cooling device is arranged inside the tank body, and a mass sensor capable of detecting the weight change of the tank body is arranged on the tank body.

[0017] Preferably, an air suction pipe for supplying cold air is externally connected to the breather tube of the cold salt tank. A one-way valve is installed between the air suction pipe and the breather tube of the cold salt tank, and the one-way valve can allow cold air to flow unidirectionally from the air suction pipe into the breather tube of the cold salt tank.

[0018] Preferably, the molten salt pump includes a cold salt pump for delivering low-temperature molten salt outward and a hot salt pump for delivering high-temperature molten salt outward. The cold salt pump is arranged in the cold salt tank, and the hot salt pump is arranged in the hot salt tank.

[0019] Preferably, the cold salt pump is connected to a molten salt heating device, and the molten salt heating device is connected to the hot salt tank;

[0020] The hot salt pump is connected to a molten salt heat release device, and the molten salt heat release device is connected to the cold salt tank.

[0021] The present utility model has achieved the following technical effects compared with the prior art:

[0022] The present utility model provides a molten salt system with a heat recovery function. During the heat storage process, the cold salt tank is used to recover the heat of the high-temperature waste gas discharged from the hot salt tank, improving the heat utilization efficiency, reducing heat loss and energy consumption. During the heat release process, the high-temperature waste gas discharged from the cold salt tank is used to supplement the hot salt tank, reducing the direct emission of high-temperature waste gas and the inhalation of cold air, and reducing heat loss and energy consumption.

[0023] The present utility model has also achieved the following technical effects compared with the prior art:

[0024] The molten salt system with a heat recovery function provided by the present utility model further includes a molten salt condensation device. The gas discharged from the cold salt tank separates the molten salt from the high-temperature gas by condensation before entering the external environment. The separated molten salt can be recycled, avoiding molten salt loss and protecting the surrounding environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 It is a schematic diagram of the overall structure of the present utility model;

[0027] Figure 2 It is a schematic diagram of the structure of the heat exchanger in the present utility model;

[0028] Figure 3 It is a schematic diagram of the structure of the molten salt condensation device in the present utility model;

[0029] Among them, 1. cold salt tank; 2. cold salt pump; 3. molten salt heating device; 4. molten salt heat release device; 5. hot salt tank; 6. hot salt pump; 7. heat exchanger; 71. breather pipe inside the tank; 72. connecting pipe between cold and hot tanks; 73. heat exchange pipe; 9. breather pipe of cold salt tank; 10. molten salt condensation device; 101. tank body; 102. exhaust inlet of cold salt tank; 103. exhaust port; 104. cooling medium inlet; 105. drain port; 106. liquid level gauge; 107. molten salt gas nozzle; 11. check valve; 12. intake pipe. Specific embodiments

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] The purpose of the present invention is to provide a molten salt system with a heat recovery function to solve the problems existing in the above-mentioned prior art. During the heat storage process, the high-temperature exhaust gas discharged from the hot salt tank is used to heat the cold salt tank to prevent the molten salt from solidifying due to the temperature drop in the cold salt tank. During the heat release process, the high-temperature exhaust gas discharged from the cold salt tank is used to heat the hot salt tank to maintain the high-temperature state in the hot salt tank.

[0032] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0033] As Figure 1 and 3 shown, the present invention provides a molten salt system with a heat recovery function, including a cold salt tank 1, a hot salt tank 5, and a heat exchanger 7. The cold salt tank 1 and the hot salt tank 5 are connected through a molten salt pump to realize the molten salt transportation. The process of the molten salt entering the hot salt tank 5 from the cold salt tank 1 is a heat storage process, and the molten salt will absorb heat during the heat storage process. The process of the molten salt entering the cold salt tank 1 from the hot salt tank 5 is a heat release process, and the molten salt will release heat during the heat release process.

[0034] As Figure 1As shown, the heat exchanger 7 is disposed within the cold salt tank 1 and is in contact with the molten salt. The first air exchange port of the heat exchanger 7 is located inside the cold salt tank 1 and extends out of the molten salt liquid level of the cold salt tank (1). The second air exchange port of the heat exchanger 7 extends out of the cold salt tank 1 and enters the hot salt tank 5. The second air exchange port of the heat exchanger 7 is located above the molten salt liquid level in the hot salt tank 5. Only air circulates within the heat exchanger 7. During the heat storage process, the air in the hot salt tank 5 enters the heat exchanger 7, first undergoes heat exchange within the cold salt tank 1, and then is discharged through the cold salt tank 1. During the heat release process, the air in the cold salt tank 1 enters the hot salt tank 5 through the heat exchanger 7 to heat the hot salt tank 5.

[0035] As Figure 3 shown, the main body of the heat exchanger 7 is a heat exchange tube 73. The first air exchange port of the heat exchanger 7 is connected to the heat exchange tube 73 through an in-tank breather tube 71. The second air exchange port of the heat exchanger 7 is connected to the heat exchange tube 73 through a cold-hot tank connecting pipe 72. In a preferred embodiment, the heat exchange tube 73 is a coil tube, and the coil tube is disposed at the bottom of the cold salt tank 1. The heat exchange tube 73 can also be other structures capable of realizing heat exchange.

[0036] As Figure 1 and 3 shown, it further includes a molten salt condensation device 10. The molten salt condensation device 10 and the cold salt tank 1 are connected through a cold salt tank breather pipe 9. The molten salt condensation device 10 includes a tank body 101. A cold salt tank exhaust inlet 102, an exhaust port 103, a cooling medium inlet 104, and a drain port 105 are opened on the tank body 101. The cold salt tank 1 unidirectionally conveys high-temperature gas to the molten salt condensation device 10. A molten salt gas release device is disposed within the tank body 101, and the molten salt gas release device is connected to the cold salt tank exhaust inlet 102. A cooling medium release device is connected to the cooling medium inlet 104. The high-temperature gas discharged from the cold salt tank 1 is mixed and cooled with the cooling medium within the molten salt condensation device 10. The cooling medium can be cold air, cold water, or a solution capable of dissolving molten salt, etc. The molten salt obtained by condensation remains within the tank body 101, and the clean gas after removing the molten salt vapor is discharged from the exhaust port 103. When the recovered amount of molten salt is reached, the drain port 105 is opened to discharge the mixture composed of the molten salt and the condensation medium together. The drain port 105 can also be in an always-open state to discharge the mixture at any time.

[0037] As Figure 3As shown, the cooling medium inlet 104 is a water inlet. A liquid level gauge 106 is also provided inside the tank body 101. The liquid level gauge 106 includes a measurement low level and a measurement high level. Cooling is carried out by spraying or dissolving. The liquid level height inside the tank body 101 is between the measurement low level and the measurement high level. The molten salt gas release device includes a molten salt gas spray pipe 107 communicating with the exhaust inlet 102 of the cold salt tank. Molten salt gas nozzles are provided on the molten salt gas spray pipe 107. The position of the molten salt gas spray pipe 107 is lower than the horizontal plane where the high liquid level gauge is located. In a preferred embodiment, the cooling medium release device is a spray pipe, and the spray pipe is higher than the molten salt gas spray pipe 107. During operation, the cooling water sprays the high-temperature gas discharged from the cold salt tank 1 to separate the molten salt from the gas.

[0038] A partition wall type cooling device can also be provided inside the tank body 101. A mass sensor capable of detecting changes in the weight of the tank body is provided on the tank body 101. The partition wall type cooling device can cause the molten salt to condense on the inner wall of the tank body 101. The total amount of molten salt obtained is judged through the measurement data of the mass sensor. When it is necessary to discharge the molten salt, open the cooling medium inlet 104 to introduce water or a dissolution liquid into the tank body, so that the molten salt detaches from the inner wall of the tank body 101, and then open the drain port 105 to discharge the mixture. Coiled tube type, fin type and other tube plate-shaped coolers can be further provided inside the tank body 101 to increase the contact area with the high-temperature exhaust gas and improve the cooling effect.

[0039] As Figure 3 As shown, an air suction pipe 12 for providing cold air is externally connected to the breather pipe 9 of the cold salt tank. A check valve 11 is installed between the air suction pipe 12 and the breather pipe 9 of the cold salt tank. The check valve 11 can allow cold air to flow unidirectionally from the air suction pipe 12 into the breather pipe 9 of the cold salt tank. The check valve 11 can prevent the high-temperature gas discharged from the cold salt tank 1 from directly entering the external environment.

[0040] As Figure 1 As shown, the molten salt pump includes a cold salt pump 2 for externally transporting low-temperature molten salt and a hot salt pump 6 for externally transporting high-temperature molten salt. The cold salt pump 2 is arranged inside the cold salt tank 1, and the hot salt pump 6 is arranged inside the hot salt tank 5. The cold salt pump 2 communicates with a molten salt heating device 3, the molten salt heating device 3 communicates with the hot salt tank 5, the hot salt pump 6 communicates with a molten salt heat release device 4, and the molten salt heat release device 4 communicates with the cold salt tank 1. The molten salt heating device 3 can be a solar heating device, an electric heating device, a fire heating device and other heating devices, and the molten salt heat release device 4 can be a thermal power generator, a heating device and the like.

[0041] In this utility model, specific examples are used to elaborate on the principle and implementation manner of the utility model. The description of the above embodiments is only used to help understand the method and its core idea of the utility model; at the same time, for those of ordinary skill in the art, according to the idea of the utility model, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation on the utility model.

Claims

1. A molten salt system with heat recovery function, characterized in that: It comprises a cold salt tank (1), a hot salt tank (5) and a heat exchanger (7), wherein the cold salt tank (1) and the hot salt tank (5) realize molten salt transportation through a molten salt pump; The heat exchanger (7) is arranged in the cold salt tank (1) and is in contact with the molten salt. The first ventilation port of the heat exchanger (7) is located inside the cold salt tank (1) and extends out of the molten salt liquid level of the cold salt tank (1). The second ventilation port of the heat exchanger (7) extends from the cold salt tank (1) and enters the hot salt tank (5). The second ventilation port of the heat exchanger (7) is located above the molten salt liquid level in the hot salt tank (5).

2. The molten salt system with heat recovery function according to claim 1, characterized in that: The main body of the heat exchanger (7) is a heat exchange tube (73); the first ventilation port of the heat exchanger (7) is connected to the heat exchange tube (73) via a breathing tube (71) in the tank; and the second ventilation port of the heat exchanger (7) is connected to the heat exchange tube (73) via a cold and hot tank connecting tube (72).

3. The molten salt system with heat recovery function according to claim 2, characterized in that: The heat exchange tube (73) is a coil, and the coil is arranged at the bottom of the cold salt tank (1).

4. The molten salt system with heat recovery function according to claim 1, characterized in that: It also includes a molten salt condensation device (10), wherein the molten salt condensation device (10) and the cold salt tank (1) are connected via a cold salt tank breathing pipe (9); The molten salt condensation device (10) comprises a tank body (101), on which a cold salt tank exhaust inlet (102), an exhaust port (103), a cooling medium inlet (104) and a drain port (105) are provided. The cold salt tank (1) transports high-temperature gas to the molten salt condensation device (10) in a unidirectional manner. A molten salt gas release device is arranged in the tank body (101), the molten salt gas release device is connected to the cold salt tank exhaust inlet (102), and the cooling medium release device is connected to the cooling medium inlet (104). The high-temperature gas discharged from the cold salt tank (1) is mixed with the cooling medium and cooled in the molten salt condensation device (10).

5. The molten salt system with heat recovery function according to claim 4, characterized in that: The cooling medium inlet (104) is a water inlet, and a liquid level meter (106) is also provided in the tank body (101), and the liquid level meter (106); The molten salt gas release device comprises a molten salt gas nozzle (107) connected to the exhaust inlet (102) of the cold salt tank, a molten salt gas nozzle is arranged on the molten salt gas nozzle (107), and the position of the molten salt gas nozzle (107) is lower than the horizontal plane where the measurement high position of the liquid level meter (106) is located.

6. The molten salt system with heat recovery function according to claim 5, characterized in that: The cooling medium release device is a spray pipe, and the spray pipe is higher than the molten salt gas spray pipe (107).

7. The molten salt system with heat recovery function according to claim 4, characterized in that: A partition-type cooling device is arranged inside the tank body (101), and a mass sensor capable of detecting changes in the tank body weight is arranged on the tank body (101).

8. The molten salt system with heat recovery function according to claim 4, characterized in that: The cold salt tank breathing pipe (9) is externally connected to an air intake pipe (12) for providing cold air, and a one-way valve (11) is installed between the air intake pipe (12) and the cold salt tank breathing pipe (9). The one-way valve (11) allows cold air to flow from the air intake pipe (12) into the cold salt tank breathing pipe (9) in a one-way manner.

9. The molten salt system with heat recovery function according to claim 1, characterized in that: The molten salt pump comprises a cold salt pump (2) for transporting low-temperature molten salt to the outside and a hot salt pump (6) for transporting high-temperature molten salt to the outside. The cold salt pump (2) is arranged in the cold salt tank (1), and the hot salt pump (6) is arranged in the hot salt tank (5).

10. The molten salt system with heat recovery function according to claim 9, characterized in that: The cold salt pump (2) is connected to a molten salt heating device (3), and the molten salt heating device (3) is connected to the hot salt tank (5); The hot salt pump (6) is connected to the molten salt heat release device (4), and the molten salt heat release device (4) is connected to the cold salt tank (1).

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