Tank-type heat storage system capable of replacing fused salt heat storage

Abstract

The utility model discloses a tank type heat storage system capable of replacing fused salt heat storage, which comprises a solid heat storage device, a low-level fused salt storage tank and a heat utilization end, the low-level fused salt storage tank is communicated with the solid heat storage device and the heat utilization end through pipelines, and the solid heat storage device is higher than the low-level fused salt storage tank. The utility model has the characteristics that the single body design is adopted, the investment of cold and hot tanks and pipelines is reduced, the inclined design is adopted for the steel pipe and the pipelines, the fused salt can flow into the low-position fused salt storage tank by self weight, the heat preservation cost is reduced, the fused salt is only a heat transfer medium, the use amount is very small, the cost is greatly reduced, and meanwhile, the cost of the solid heat storage material is low.

Description

Technical Field

[0001] The utility model relates to the technical field related to heat storage, and in particular to a heat storage system that can replace a molten salt heat storage tank. Background Art

[0002] Currently, the widely used molten salt heat storage systems are mostly double-tank structures, that is, two molten salt storage tanks are used to store high-temperature molten salt and low-temperature molten salt. The double-tank heat storage system consumes a huge amount of salt, and the cost of molten salt is very high, which has poor economic efficiency and seriously restricts the development of the molten salt heat storage industry. In addition, after the equipment is shut down, the existing molten salt heat storage system needs to add an electric heating and insulation system to the molten salt pipeline to prevent the molten salt from cooling and hardening. Utility Model Content

[0003] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a heat storage system that can replace the molten salt heat storage tank type.

[0004] The technical solution adopted by the present invention to achieve the above-mentioned purpose is:

[0005] A heat storage system that can replace a molten salt heat storage tank, comprising a solid heat storage device, a low-position molten salt storage tank, and a heat-using end, wherein the solid heat storage device is higher than the low-position molten salt storage tank;

[0006] The solid heat storage device comprises a heat-insulating cavity, a box is installed in the heat-insulating cavity, a ventilation hole is opened on the bottom surface of the box, an internal circulation air duct is formed between the heat-insulating cavity and the box, and the box is connected with the internal circulation air duct through the ventilation hole, the box is filled with solid heat storage material, a steel pipe is obliquely inserted in the box, one end of the steel pipe is a high-position port of the steel pipe, and the other end is a low-position port of the steel pipe, a left molten salt equalizing cavity is formed between the high-position port of the steel pipe and the heat-insulating cavity, and a right molten salt equalizing cavity is formed between the low-position port of the steel pipe and the heat-insulating cavity, a heater is installed below the box, and a variable frequency centrifugal fan is arranged above the box, the air inlet of the variable frequency centrifugal fan is correspondingly connected to the top of the box, and the air outlet of the variable frequency centrifugal fan is connected to the internal circulation air duct;

[0007] The low-level molten salt storage tank is filled with molten salt, and a molten salt heater is installed in the low-level molten salt storage tank. The low-level molten salt storage tank is connected to the molten salt equal distribution chamber on the right side through pipeline one, and the first outlet valve and the second outlet valve are provided on the pipeline one. The low-level molten salt storage tank is connected to the molten salt equal distribution chamber on the left side through pipeline two, and a molten salt pump, a molten salt heating system, a first inlet valve, and a second inlet valve are sequentially provided on the pipeline two. The pipeline two is located between the first inlet valve and the second inlet valve and is connected to the heat-using end through pipeline three, and the pipeline three is provided with a third inlet valve and a circulation pump. The pipeline one is located between the first outlet valve and the second outlet valve and is connected to the heat-using end through pipeline four, and the pipeline four is provided with the third outlet valve.

[0008] The box body is supported on the bottom surface of the heat preservation cavity by a supporting body.

[0009] A perforated evenly-dividing isolation plate is installed above the box body, and the perforated evenly-dividing isolation plate is communicated with the air inlet of the variable-frequency centrifugal fan.

[0010] A temperature monitoring system is installed in the box.

[0011] The heater is an electric heater and / or a steam heater.

[0012] The steel pipe is supported in the box by a support plate.

[0013] The steel pipe is provided with an expansion joint.

[0014] The steel pipe is U-shaped, and the left molten salt equalizing chamber and the right molten salt equalizing chamber are on the same side.

[0015] The steel pipe has an inclination angle of 3°-5°.

[0016] The heat-insulating cavity is provided with a moisture-discharging hole.

[0017] The utility model is characterized by adopting a single body design, which reduces the investment in hot and cold tanks and pipelines; the steel pipes and pipelines are designed to be inclined, so that the molten salt can flow into the low-position molten salt storage tank by its own weight, reducing the insulation cost; and the molten salt is only a heat transfer medium, and the usage is very small, which greatly reduces the cost; at the same time, the cost of solid heat storage materials is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural diagram of the present utility model.

[0019] Figure 2 yes Figure 1 AA cross-sectional view.

[0020] Figure 3This is a schematic structural diagram of the solid heat storage device of the present invention. The arrow direction in the figure is the direction when storing heat, and the opposite direction when releasing heat.

[0021] Figure 4 The figure is a schematic diagram of the U-shaped steel pipe of the present invention. The arrow direction in the figure is the direction when storing heat, and the opposite direction when releasing heat.

[0022] Including: 1. Solid heat storage device 2. Support body 3. Box body 4. Steel pipe 5. Expansion joint 6. Support plate 7. High-position outlet of steel pipe 8. Low-position outlet of steel pipe 9. Solid heat storage material 10. Electric heater 11. Steam heater 12. Air-distributing isolation plate with holes 13. Left molten salt distributing chamber 14. Right molten salt distributing chamber 15. Internal circulation air duct 16. Frequency conversion centrifugal fan 17. Air inlet 18. Air outlet 19. Moisture discharge hole 20. Temperature monitoring system 21. Pipeline 1 22. Pipeline 3 23. Pipe Route four 24, molten salt pump 25, pipeline two 26, low-level molten salt storage tank 27, molten salt 28, molten salt heating system 29, upper molten salt port 30, lower molten salt port 31, molten salt heater 32, insulation cavity 33, heat-using end 34, circulation pump 51, first valve 52 at the inlet end, second valve 53 at the inlet end, third valve 61 at the inlet end, first valve 62 at the outlet end, second valve 63 at the outlet end, third valve 64 at the outlet end, high-temperature steam inlet 65, low-temperature steam outlet 66, and inspection door. DETAILED DESCRIPTION

[0023] like Figure 1-4 As shown, the utility model is a heat storage system that can replace a molten salt heat storage tank, comprising a solid heat storage device 1, a low-position molten salt storage tank 26, and a heat-using end 33, wherein the solid heat storage device 1 is higher than the low-position molten salt storage tank 26.

[0024] The solid heat storage device 1 includes a heat preservation cavity 32, a moisture discharge hole 19 is provided on the heat preservation cavity 32, an inspection door 66 is installed on the heat preservation cavity 32, a box 3 is installed in the heat preservation cavity 32, the box 3 is supported on the bottom surface of the heat preservation cavity 32 by a support body 2, an internal circulation air duct 15 is formed between the heat preservation cavity 32 and the box 3, a ventilation hole is provided on the bottom surface of the box 3, the box 3 is connected to the internal circulation air duct 15 through the ventilation hole, a plurality of steel pipes 4 are obliquely inserted in the box 3, and a European The expansion joint 5 in the shape of a mega is used to absorb the expansion and contraction deformation of the steel pipe. One end of the steel pipe 4 is a high-position opening 7 of the steel pipe and the other end is a low-position opening 7 of the steel pipe. The steel pipe 4 is supported in the box 3 by a support plate 6, and the high-position opening 7 and the low-position opening 8 of the steel pipe have a height difference of about 3°-5°. A left molten salt equalizing chamber 13 is formed between the high-position opening 7 of the steel pipe and the insulation cavity 32, and a right molten salt equalizing chamber 14 is formed between the low-position opening 8 of the steel pipe and the insulation cavity 32. The steel pipe 4 can be a smooth pipe or a finned pipe. It can be a straight tube or a U-shaped tube. When the steel tube 4 is in a U-shape, the left molten salt equalizing chamber 13 and the right molten salt equalizing chamber 14 are on the same side. The box body 3 is also filled with a solid heat storage material 9. The solid heat storage material 9 adopts solid heat storage particles. There can be enough air gaps and ventilation ducts between the particles. The solid heat storage material 9 can be made of natural pebbles, rocks, and balls or bricks made of waste slag. A temperature monitoring system 20 is installed in the solid heat storage material 9 of the box body 3. A heater is installed under the box body 3. The heater is an electric heater. The heater 10 and / or steam heater 11 has the same function as the electric heater 10. When the steel pipe 4 and the solid heat storage material 9 need to be heated, high-temperature steam enters the steam heater 11 from the high-temperature steam inlet 64, and low-temperature steam exits from the low-temperature steam outlet 65. A perforated evenly-dividing isolation plate 12 is installed above the box body 3. The perforated evenly-dividing isolation plate 12 is connected to the air inlet 17 of the variable-frequency centrifugal fan 16 installed on the insulation cavity 32, and the air outlet 18 of the variable-frequency centrifugal fan 16 is connected to the internal circulation air duct 15.

[0025] The low-level molten salt storage tank 26 is filled with molten salt 27, and a molten salt heater 31 is installed in the low-level molten salt storage tank 26. The low-level molten salt storage tank 26 is connected to the right molten salt equal distribution chamber 14 through a pipeline 1 21. The pipeline 1 21 is provided with a first outlet valve 61 and a second outlet valve 62. The low-level molten salt storage tank 26 is connected to the left molten salt equal distribution chamber 13 through a pipeline 2 25. The pipeline 2 25 is sequentially provided with a molten salt pump 24, a molten salt heating system 28, a first inlet valve 51, and a second inlet valve 52. The molten salt heating system 28 can adopt a solar energy heating molten salt system. If this The system is used in a thermal power plant, and low-cost steam or electricity in the power plant can be used instead of solar energy to heat the molten salt. The pipeline 2 25 is located between the first valve 51 at the inlet end and the second valve 52 at the inlet end, and is connected to the heat-using end 33 through the pipeline 3 22. The pipeline 3 22 is provided with the third valve 53 at the inlet end and a circulating pump 34. The pipeline 1 21 is located between the first valve 61 at the outlet end and the second valve 62 at the outlet end, and is connected to the heat-using end 33 through the pipeline 4 23. The pipeline 4 23 is provided with the third valve 63 at the outlet end. The pipeline 1 21, pipeline 2 25, pipeline 3 22, and pipeline 4 23 all contain electric heating cables.

[0026] During the initial operation, the electric heater 10 and the variable frequency centrifugal fan 16 are turned on. Under the action of the variable frequency centrifugal fan 16, heat is transferred to the steel pipe 4 and the solid heat storage material 9. The low-temperature hot air passes through the perforated air-distributing isolation plate 12 and returns to the air inlet 17 of the variable frequency centrifugal fan 16. The air coming out of the air outlet 18 of the variable frequency centrifugal fan 16 passes through the internal circulation air duct 15 and returns to the electric heater 10 to become high-temperature hot air again. When the temperature monitoring system 20 shows that the temperature in the box 3 is higher than the freezing point of the molten salt, the heating is stopped and the variable frequency centrifugal fan 16 is turned off. While heating, the moisture in the solid heat storage material 9 is also discharged through the moisture discharge hole 19. Open the first valve 51 at the inlet end and the second valve 52 at the inlet end. , the first valve 61 at the outlet end, the second valve 62 at the outlet end, close the third valve 53 at the inlet end and the third valve 63 at the outlet end, start the molten salt pump 24, and send the molten salt 27 in the low-level molten salt storage tank 26 into the molten salt heating system 28 through the pipeline 25. The molten salt heating system 28 will heat the low-temperature molten salt to high-temperature molten salt, and then enter the left molten salt equal distribution chamber 13 through the upper molten salt port 29 opened in the insulation chamber 32, and then enter the steel pipe 4 from the high-level port 7 of the steel pipe. At this time, the heat of the high-temperature molten salt will be transferred to the solid heat storage material 9. The low-temperature molten salt after heat exchange enters the right molten salt equal distribution chamber 14 from the low-level port 8 of the steel pipe, and then returns to the pipeline 1 21 through the lower molten salt port 30 opened in the insulation chamber 32. , and finally flows back to the low-level molten salt storage tank 26. Because a molten salt heater 31 is provided at the bottom of the low-level molten salt storage tank 26, the molten salt 27 will always be kept above the freezing point temperature, so that the molten salt 27 can continuously heat the solid heat storage material 9 to the maximum use temperature. At the same time, in order to make the temperature of the solid heat storage material 9 uniform, the variable frequency centrifugal fan 16 can be turned on to make the heat transfer faster and more uniform. When the hot end 33 needs heat, first close the second valve 52 at the inlet end and the first valve 61 at the outlet end, open the first valve 51 at the inlet end, the third valve 53 at the inlet end, the second valve 62 at the outlet end, and the third valve 63 at the outlet end, start the molten salt pump 24, and pass the molten salt 27 in the low-level molten salt storage tank 26 to the molten salt 27. The molten salt is fed into the third valve 53 at the inlet end and into the pipeline 3 and pipeline 4 where the third valve 63 at the outlet end is located; then the molten salt pump 24 is closed, the first valve 51 at the inlet end and the second valve 62 at the outlet end are closed, the second valve 52 at the inlet end, the third valve 53 at the inlet end, the first valve 61 at the outlet end, and the third valve 63 at the outlet end are opened, and the circulation pump 34 and the variable frequency centrifugal fan 16 are started, so that the high-temperature molten salt in the steel pipe 4 flows from the low-level port 8 of the steel pipe to the high-level port 7 of the steel pipe, and passes through the left molten salt equalizing chamber 13 and the upper molten salt port 29 in turn to enter the hot end 33 for heat exchange. At this time, the heat in the molten salt can be obtained through various heat exchangers to obtain the needs of high-temperature steam, thermal oil, hot air, hot water, etc.After heat exchange, the low-temperature molten salt passes through the lower molten salt inlet 30, the right molten salt equalization chamber 14, and the low-level steel pipe inlet 8, entering the steel pipe 4, where it exchanges heat with the solid heat storage material 9 again. The variable-frequency centrifugal fan 16 ensures faster and more uniform heat transfer. When the temperature monitoring system 20 detects that the temperature of the solid heat storage material 9 has dropped close to the freezing point of the molten salt, the system automatically activates the heater to prevent the molten salt from solidifying. When the system is ready to shut down, because the solid heat storage device 1 is higher than the low-level molten salt storage tank 26, and because pipeline 2 25 and the steel pipe 4 are both inclined, the molten salt 27 can flow back into the low-level molten salt storage tank 26 by its own gravity.

[0027] The utility model adopts a single body design, which does not require a conventional hot tank and a cold tank, thus reducing the investment in hot and cold tanks. Since the steel pipe is designed with a height difference of about 3-5 degrees, the molten salt can flow into the low-position molten salt storage tank by its own weight when not in use for a long time or after shutdown for major repairs. Since all components of the solid heat storage device are in the insulation cavity, the pipe connection between the cold tank and the hot tank is saved. When not in use, the molten salt flows into the low-position molten salt storage tank, reducing the cost of electric heating insulation. Moreover, the molten salt is only a heat transfer medium in this system and is used in very small amounts, which greatly reduces the cost. At the same time, the cost of solid heat storage materials is low, only a few tens of times that of nitrate or other mixed molten salts.

[0028] The utility model can be used for heat storage in solar thermal power stations to replace cold and hot salt tanks and molten salt heat storage, can also be used for peak regulation in power plants to store electricity or steam heat for secondary power generation, and can also be used to meet the working needs of electric heat storage and steam output or steam heat storage and then steam output.

[0029] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed in the present invention can make equivalent replacements or changes based on the technical solution and inventive concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A heat storage system that can replace molten salt heat storage tanks, characterized by: It includes a solid heat storage device, a low-position molten salt storage tank, and a heat-using end, wherein the solid heat storage device is higher than the low-position molten salt storage tank; The solid heat storage device comprises a heat-insulating cavity, a box is installed in the heat-insulating cavity, a ventilation hole is opened on the bottom surface of the box, an internal circulation air duct is formed between the heat-insulating cavity and the box, and the box is connected with the internal circulation air duct through the ventilation hole, the box is filled with solid heat storage material, a steel pipe is obliquely inserted in the box, one end of the steel pipe is a high-position port of the steel pipe, and the other end is a low-position port of the steel pipe, a left molten salt equalizing cavity is formed between the high-position port of the steel pipe and the heat-insulating cavity, and a right molten salt equalizing cavity is formed between the low-position port of the steel pipe and the heat-insulating cavity, a heater is installed below the box, and a variable frequency centrifugal fan is arranged above the box, the air inlet of the variable frequency centrifugal fan is correspondingly connected to the top of the box, and the air outlet of the variable frequency centrifugal fan is connected to the internal circulation air duct; The low-level molten salt storage tank is filled with molten salt, and a molten salt heater is installed in the low-level molten salt storage tank. The low-level molten salt storage tank is connected to the molten salt equal distribution chamber on the right side through pipeline one, and the first outlet valve and the second outlet valve are provided on the pipeline one. The low-level molten salt storage tank is connected to the molten salt equal distribution chamber on the left side through pipeline two, and a molten salt pump, a molten salt heating system, a first inlet valve, and a second inlet valve are sequentially provided on the pipeline two. The pipeline two is located between the first inlet valve and the second inlet valve and is connected to the heat-using end through pipeline three, and the pipeline three is provided with a third inlet valve and a circulation pump. The pipeline one is located between the first outlet valve and the second outlet valve and is connected to the heat-using end through pipeline four, and the pipeline four is provided with the third outlet valve.

2. The heat storage system as claimed in claim 1, wherein: The box body is supported on the bottom surface of the heat preservation cavity by a supporting body.

3. The heat storage system that can replace molten salt heat storage tank according to claim 1, characterized in that: A perforated evenly-dividing isolation plate is installed above the box body, and the perforated evenly-dividing isolation plate is communicated with the air inlet of the variable-frequency centrifugal fan.

4. The heat storage system that can replace molten salt heat storage tank according to claim 1, characterized in that: A temperature monitoring system is installed in the box.

5. The heat storage system that can replace molten salt heat storage tank according to claim 1, characterized in that: The heater is an electric heater and / or a steam heater.

6. The alternative molten salt heat storage tank type thermal storage system according to claim 1, characterized in that: The steel pipe is supported in the box by a support plate.

7. The alternative molten salt heat storage tank type thermal storage system according to claim 1, characterized in that: The steel pipe is provided with an expansion joint.

8. The alternative molten salt heat storage tank type thermal storage system according to claim 1, characterized in that: The steel pipe is U-shaped, and the left molten salt equalizing chamber and the right molten salt equalizing chamber are on the same side.

9. The alternative molten salt heat storage tank type thermal storage system according to claim 1, characterized in that: The steel pipe has an inclination angle of 3°-5°.

10. The heat storage system that can replace molten salt heat storage tank according to claim 1, characterized in that: The heat-insulating cavity is provided with a moisture-discharging hole.

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