Steam pressure stabilizing system of fused salt heat storage type steam generator

Abstract

The utility model provides a steam pressure stabilizing system of a fused salt heat storage type steam generator, which is characterized in that a heat storage medium is accommodated in a heat storage structure, a heat exchange structure is in heat conduction contact with the heat storage medium, a through steam-water pipeline is arranged in the heat exchange structure, and the steam-water pipeline is used for conveying water and steam generated by heating the water by the heat storage medium; a water supply pipeline and a steam pipeline are arranged at the liquid inlet end and the steam outlet end of the heat exchange structure respectively, a water supply buffer tank is arranged in the water supply pipeline, when the mixing pressure of water and steam in the steam-water pipeline is lower than a preset first pressure value, an opening of the water supply buffer tank is closed, and the water supply pipeline supplies water flowing in the first direction to the steam-water pipeline; when the mixed pressure of the feed water and the steam in the steam-water pipeline is higher than the first pressure value, the opening of the feed water buffer tank is opened, and the feed water in the steam-water pipeline flows back into the feed water buffer tank in the direction opposite to the first direction until the mixed pressure of the feed water and the steam in the steam-water pipeline is lower than the first pressure value again.

Description

Technical Field

[0001] This utility model belongs to the field of steam generator technology, and in particular relates to a steam pressure stabilization system for a molten salt thermal storage steam generator. Background Technology

[0002] A molten salt thermal storage steam generator is a device that uses molten salt as a thermal storage medium. It is mainly used to store thermal energy and release heat to generate steam when needed.

[0003] In the initial stage of heat release in a molten salt thermal storage steam generator, the temperature of the heat storage medium is high. At this time, the feedwater introduced into the molten salt thermal storage steam generator will quickly generate steam. The rapidly generated and large amount of steam cannot be discharged in time through the steam pipeline, resulting in large fluctuations in the internal pressure of the molten salt thermal storage steam generator. At the same time, when the user stops using steam, there will still be unvaporized feedwater inside the molten salt thermal storage steam generator, which will continue to generate steam, causing the internal pressure of the molten salt thermal storage steam generator to gradually increase, affecting equipment safety.

[0004] In summary, the use of low-pressure steam on a small to medium scale is usually intermittent and involves frequent start-ups and shutdowns. Due to the large fluctuations in steam load and the significant temperature changes of the heat storage medium during the daily reheating phase, it is difficult for molten salt thermal storage steam generators to maintain stable steam output, which is not conducive to user operation.

[0005] Under current technology, stable steam output can be ensured by adding a steam buffer tank on the steam side. This technology can solve the problem of steam stability under continuous steam use conditions, but it is difficult to solve the problem of steam temperature change when the external load changes during start-up and shutdown. In addition, when the temperature of the heat storage medium inside the molten salt heat storage type steam generator is high, conventional steam buffer tanks cannot quickly absorb a large amount of steam. Larger steam buffer tanks are required to absorb the instantaneously generated steam, which is less economical and safer. Utility Model Content

[0006] This utility model aims to provide a steam pressure stabilization system for a molten salt thermal storage steam generator, in order to solve the technical problem that conventional molten salt thermal storage steam generators cannot safely and efficiently achieve steam generation and output under the existing technology.

[0007] To solve the above problems, the technical solution of this utility model is: a steam pressure stabilization system for a molten salt thermal storage steam generator, comprising:

[0008] A heat storage structure, wherein the heat storage structure has an internal accommodating space, and the accommodating space contains a heat storage medium;

[0009] A heat exchange structure is provided, which passes through the accommodating space of the heat storage structure and has direct or indirect heat conduction contact with the heat storage medium. The heat exchange structure is provided with a through steam-water pipeline, which is used to transmit feed water and steam generated by the feed water being heated by the heat storage medium.

[0010] The heat exchange structure is provided with a water supply pipeline and a steam pipeline at the liquid inlet end and the steam outlet end, respectively, and a water supply buffer tank is provided in the water supply pipeline.

[0011] Let the direction of water flow from the water supply pipeline toward the steam-water pipeline be the first direction;

[0012] The water supply buffer tank is configured such that when the mixing pressure of water and steam in the steam-water pipeline is lower than a preset first pressure value, the opening of the water supply buffer tank is closed, and water flowing in a first direction is supplied from the water supply pipeline to the steam-water pipeline; when the mixing pressure of water and steam in the steam-water pipeline is higher than the first pressure value, the opening of the water supply buffer tank is opened, and the water in the steam-water pipeline flows back to the water supply buffer tank in a direction opposite to the first direction, until the mixing pressure of water and steam in the steam-water pipeline is lower than the first pressure value again.

[0013] Preferably, the heat storage structure is a cylindrical molten salt storage tank, and the heat storage medium is molten salt including but not limited to binary or ternary salts.

[0014] Preferably, the heat exchange structure extends along the height direction of the heat storage structure in a spiral arrangement.

[0015] Preferably, a check valve is provided in the water supply pipeline, and the opening of the water supply pipeline and the water supply buffer tank form a junction node. The output end of the check valve is connected to the junction node of the water supply pipeline and the water supply buffer tank. The check valve is used to restrict the backflow of water in the steam-water pipeline to the water supply pipeline on the side of the input end of the check valve.

[0016] Preferably, the water supply pipeline is equipped with a water supply valve, the output end of which is connected to the input end of the check valve, and the water supply valve is used to regulate the flow rate of water supplied unidirectionally from the water supply pipeline to the steam-water pipeline.

[0017] Preferably, the water supply pipeline is equipped with a water supply pump, the output end of which is connected to the input end of the water supply valve, and the water supply pump is used to provide power for the water supply to flow in the water supply pipeline and the steam-water pipeline in the first direction.

[0018] Preferably, the steam pressure stabilization system is further provided with a steam pressure relief pipeline, the input end of which is connected to the steam pipeline, and the output end of which is connected to the liquid storage space of the feedwater buffer tank;

[0019] The steam pressure relief pipeline is equipped with a back pressure valve. The back pressure valve is configured such that when the steam pressure in the steam pipeline and the steam-water pipeline is lower than a preset second pressure value, the back pressure valve closes, and steam is output to the outside of the molten salt thermal storage steam generator along the steam pipeline. When the steam pressure in the steam pipeline and the steam-water pipeline is higher than the second pressure value, the back pressure valve opens, and part or all of the steam is output to the feedwater buffer tank along the steam pressure relief pipeline and condenses to form feedwater again.

[0020] Preferably, the pressure range between the opening of the water supply buffer tank and the back pressure valve is manually set according to the applicable operating conditions of the molten salt thermal storage steam generator.

[0021] Preferably, the outer wall of the heat storage structure is provided with a heat insulation layer.

[0022] Because of the adoption of the above technical solution, this utility model has the following advantages and positive effects compared with the prior art:

[0023] This invention provides a steam pressure stabilization system for a molten salt thermal storage steam generator, comprising a thermal storage structure and a heat exchange structure. The feedwater pipeline of the heat exchange structure includes a feedwater buffer tank. The opening of the feedwater buffer tank can be autonomously opened and closed based on the external environmental pressure. Specifically, when feedwater is normally supplied to the molten salt thermal storage steam generator and the generator is normally outputting steam, the internal pressure of the generator remains at a normal level, and the feedwater buffer tank is closed. When the generator rapidly generates a large amount of steam, causing the mixing pressure of steam and feedwater inside the generator to exceed the normal pressure, or when the generator stops outputting steam but feedwater continues to generate steam inside, the feedwater buffer tank opens, allowing feedwater to flow back into the buffer tank, reducing steam generation inside the generator and thus lowering the mixing pressure of feedwater and steam. In this invention, the molten salt thermal storage steam generator can automatically adjust its internal feedwater storage according to its actual internal pressure, thereby adjusting the steam generation, thus solving the technical problem of unstable steam generation and internal pressure safety risks in the molten salt thermal storage steam generator. Attached Figure Description

[0024] Figure 1 This utility model provides a structural schematic diagram of a steam pressure stabilization system for a molten salt thermal storage steam generator.

[0025] Explanation of reference numerals in the attached drawings: 1: Heat storage structure; 2: Heat storage medium; 3: Heat exchange structure; 4: Water supply pipeline; 5: Steam pipeline; 6: Water supply buffer tank; 7: Check valve; 8: Water supply valve; 9: Water supply pump; 10: Steam pressure relief pipeline; 11: Back pressure valve. Detailed Implementation

[0026] The steam pressure stabilization system of a molten salt thermal storage steam generator proposed in this utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this utility model will become clearer from the following description and claims.

[0027] See Figure 1 This embodiment provides a steam pressure stabilization system for a molten salt thermal storage steam generator, which enables the molten salt thermal storage steam generator to stably generate steam and maintain its internal pressure within a safe range. The main structure of the steam pressure stabilization system includes a thermal storage structure 1, a heat exchange structure 3, and a feedwater buffer tank 6.

[0028] The heat storage structure 1 has an internal accommodating space for accommodating the heat storage medium 2.

[0029] The heat exchange structure 3 passes through the accommodating space of the heat storage structure 1. The heat exchange structure 3 has direct or indirect heat conduction contact with the heat storage medium 2. The heat exchange structure 3 is equipped with a through steam-water pipeline. The steam-water pipeline is used to transmit feed water. When the heat storage medium 2 transfers heat energy to the heat exchange structure 3, the feed water in the steam-water pipeline is heated by the heat storage medium 2 and rapidly rises in temperature to form steam, thus realizing the steam generation function of the molten salt heat storage type steam generator.

[0030] The heat exchange structure 3 is provided with a water supply pipe 4 and a steam pipe 5 at the liquid inlet and steam outlet ends, respectively. The water supply pipe 4 is used to supply water to the heat exchange structure 3, and the steam pipe 5 is used to receive the steam generated by the heat exchange structure 3 and output the steam to the outside of the molten salt thermal storage steam generator.

[0031] A water supply buffer tank 6 is provided in the water supply pipeline 4. The opening of the water supply buffer tank 6 is connected to the water supply pipeline 4, and the opening of the water supply buffer tank 6 is equipped with a valve. The opening and closing of the valve is automatically controlled by the mixed pressure of water and steam in the water supply pipeline 4.

[0032] The direction in which water flows from water supply pipe 4 toward steam and water pipe is set as the first direction.

[0033] In this embodiment, when the mixing pressure of water and steam in the steam-water pipeline is lower than a preset first pressure value, the opening of the water supply buffer tank 6 closes, and water flowing in the first direction is supplied from the water supply pipeline 4 to the steam-water pipeline, that is, water is normally supplied unidirectionally from the water supply pipeline 4 to the heat exchange structure 3. When the mixing pressure of water and steam in the steam-water pipeline is higher than the first pressure value, the opening of the water supply buffer tank 6 opens, and the water in the steam-water pipeline flows back to the water supply buffer tank 6 in the opposite direction to the first direction. Due to the reduction of water in the heat exchange structure 3, the mixing pressure of water and steam in the steam-water pipeline decreases until the mixing pressure of water and steam in the steam-water pipeline falls below the first pressure value again, and the opening of the water supply buffer tank 6 closes again.

[0034] In the existing technology, during the initial heat release phase of a conventional molten salt thermal storage steam generator, due to the high temperature of the thermal storage medium 2, the feedwater supplied from the feedwater pipeline 4 to the heat exchange structure 3 rapidly generates a large amount of steam in the steam-water pipeline. This large amount of steam cannot be discharged from the steam pipeline 5 in time, causing a rapid increase in the internal pressure of the heat exchange structure 3. Furthermore, when the user stops using steam, the steam pipeline 5 is blocked, and unvaporized feedwater remaining in the heat exchange structure 3 cannot be discharged, continuously generating steam, which again causes a rapid increase in the internal pressure of the heat exchange structure 3, affecting the operational safety of the molten salt thermal storage steam generator. With the steam pressure stabilization system provided in this application, when the internal pressure of the heat exchange structure 3 exceeds a first pressure value, the feedwater in the heat exchange structure 3 automatically flows back to the feedwater buffer tank 6, thereby reducing the amount of feedwater in the heat exchange structure 3, i.e., reducing the amount of steam generated in the heat exchange structure 3, thus lowering the internal pressure of the heat exchange structure 3 and maintaining the pressure of the steam generated by the molten salt thermal storage steam generator within a stable range.

[0035] Preferably, in one embodiment, the heat storage structure 1 is a cylindrical molten salt storage tank, and the heat storage medium 2 is molten salt including but not limited to binary salt or ternary salt.

[0036] Preferably, in one embodiment, the heat exchange structure 3 extends along the height direction of the heat storage structure 1 in a spiral arrangement. The spiral design increases the length and complexity of the water flow path in the steam-water pipeline, promotes more complete heat exchange between the water and the heat storage medium 2, thereby improving the heat transfer and steam generation efficiency of the molten salt heat storage steam generator.

[0037] Preferably, in one embodiment, a check valve 7 is provided in the water supply pipeline 4. The opening of the water supply pipeline 4 and the water supply buffer tank 6 form a junction node. The output end of the check valve 7 is connected to the junction node of the water supply pipeline 4 and the water supply buffer tank 6. The check valve 7 is used to restrict the backflow of water in the steam-water pipeline to the water supply pipeline 4 on the side of the input end of the check valve 7. That is, when the opening of the water supply buffer tank 6 is open, the water in the heat exchange structure 3 can flow back to the water supply buffer tank 6 along the water supply pipeline 4, and at most flow back to the output end of the check valve 7, but cannot flow back further to the water supply pipeline 4 on the side of the input end of the check valve 7, so as to prevent the backflow of water.

[0038] Preferably, in one embodiment, a water supply valve 8 is provided in the water supply pipeline 4. The output end of the water supply valve 8 is connected to the input end of the check valve 7. The water supply valve 8 is used to regulate the flow rate of water supplied unidirectionally from the water supply pipeline 4 to the steam-water pipeline. When the opening degree of the water supply valve 8 is larger, the amount of water supplied from the water supply pipeline 4 to the heat exchange structure 3 increases, that is, the amount of steam generated by the molten salt thermal storage steam generator increases. Conversely, when the opening degree of the water supply valve 8 is smaller, the amount of water supplied from the water supply pipeline 4 to the heat exchange structure 3 decreases, that is, the amount of steam generated by the molten salt thermal storage steam generator decreases. By adjusting the opening degree of the water supply valve 8 manually or automatically, the steam generation of the molten salt thermal storage steam generator can be flexibly adjusted.

[0039] Preferably, in one embodiment, a water supply pump 9 is provided in the water supply pipeline 4, and the output end of the water supply pump 9 is connected to the input end of the water supply valve 8. The water supply pump 9 is used to provide power for the water supply to flow in the water supply pipeline 4 and the steam-water pipeline in the first direction.

[0040] Preferably, in one embodiment, a steam pressure relief pipeline 10 is further provided, the input end of the steam pressure relief pipeline 10 is connected to the steam pipeline 5, and the output end of the steam pressure relief pipeline 10 is connected to the liquid storage space of the water supply buffer tank 6.

[0041] A back pressure valve 11 is provided in the steam pressure relief pipeline 10. The back pressure valve 11 can automatically open and close according to the gas pressure value in the steam pressure relief pipeline 10. That is, in this embodiment, when the steam pressure in the steam pipeline 5 and the steam-water pipeline is lower than the preset second pressure value, the back pressure valve 11 closes. At this time, steam can only be output to the outside of the molten salt thermal storage steam generator along the steam pipeline 5. When the steam pressure in the steam pipeline 5 and the steam-water pipeline is higher than the second pressure value, the back pressure valve 11 opens, that is, the steam pressure relief pipeline 10 is open. At this time, some or all of the steam can be output to the feedwater buffer tank 6 along the steam pressure relief pipeline 10 and condensed in the feedwater buffer tank 6 to re-form feedwater.

[0042] In this embodiment, when a large amount of steam is rapidly generated in the steam-water pipeline, and this large amount of steam cannot be discharged from the steam pipeline 5 in time, causing the internal pressure of the heat exchange structure 3 to increase rapidly, and when the user stops or reduces the use of steam, the steam pipeline 5 is blocked, and there is still unvaporized feedwater in the heat exchange structure 3, which will continuously generate steam, causing the internal pressure of the heat exchange structure 3 to increase rapidly, in addition to opening the feedwater buffer tank 6 to reduce the amount of feedwater in the heat exchange structure 3 and reduce the amount of steam generated by the heat exchange structure 3, the excess steam in the heat exchange structure 3 can also be guided to condense and flow back to the feedwater buffer tank 6 through the steam pressure relief pipeline 10, further reducing the steam pressure in the heat exchange structure 3, thereby realizing the function of rapid and precise adjustment of steam pressure in the molten salt thermal storage type steam generator.

[0043] Preferably, in one embodiment, the pressure range between the opening of the water supply buffer tank 6 and the back pressure valve 11 can be manually set according to the applicable operating conditions of the molten salt thermal storage steam generator to adapt to different usage requirements.

[0044] Preferably, in one embodiment, the outer wall of the heat storage structure 1 is provided with a heat insulation layer. The heat insulation layer can effectively slow down the transfer of heat from the heat storage structure 1 to the external environment, reduce unnecessary heat loss, and thus maintain the steam generation stability of the molten salt heat storage steam generator.

[0045] In summary, this embodiment provides a steam pressure stabilization system for a molten salt thermal storage steam generator, comprising a thermal storage structure 1 and a heat exchange structure 3. A feedwater buffer tank 6 is installed in the feedwater pipeline 4 of the heat exchange structure 3. The opening of the feedwater buffer tank 6 can be autonomously opened and closed based on the external environmental pressure. That is, when feedwater is normally supplied to the molten salt thermal storage steam generator and the molten salt thermal storage steam generator is normally outputting steam to the outside, the internal pressure of the molten salt thermal storage steam generator is maintained at a normal level, at which time the feedwater buffer tank 6 is closed; when molten salt... When a thermal storage steam generator rapidly generates a large amount of steam, causing the mixing pressure of steam and feedwater inside the molten salt thermal storage steam generator to exceed the normal pressure, or when the molten salt thermal storage steam generator stops outputting steam but feedwater continues to generate steam inside, the feedwater buffer tank 6 opens. This allows the feedwater inside the molten salt thermal storage steam generator to flow back into the feedwater buffer tank 6, reducing the generation of steam inside the molten salt thermal storage steam generator, i.e., lowering the mixing pressure of feedwater and steam. In this application, the molten salt thermal storage steam generator can automatically adjust its internal feedwater level according to its actual internal pressure, thereby adjusting the steam generation. This solves the technical problem of unstable steam generation and internal pressure safety risks in molten salt thermal storage steam generators. Furthermore, the overall structure of the steam pressure stabilization system of the molten salt thermal storage steam generator is simple, and it can achieve long-term stable operation under various complex operating conditions.

[0046] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they shall still fall within the protection scope of the present invention.

Claims

1. A steam pressure stabilization system for a molten salt thermal storage steam generator, characterized in that, include: A heat storage structure, wherein the heat storage structure has an internal accommodating space, and the accommodating space contains a heat storage medium; A heat exchange structure is provided, which passes through the accommodating space of the heat storage structure and has direct or indirect heat conduction contact with the heat storage medium. The heat exchange structure is provided with a through steam-water pipeline, which is used to transmit feed water and steam generated by the feed water being heated by the heat storage medium. The heat exchange structure is provided with a water supply pipeline and a steam pipeline at the liquid inlet end and the steam outlet end, respectively, and a water supply buffer tank is provided in the water supply pipeline. Let the direction of water flow from the water supply pipeline toward the steam-water pipeline be the first direction; The water supply buffer tank is configured such that when the mixing pressure of water and steam in the steam-water pipeline is lower than a preset first pressure value, the opening of the water supply buffer tank is closed, and water flowing in a first direction is supplied from the water supply pipeline to the steam-water pipeline; when the mixing pressure of water and steam in the steam-water pipeline is higher than the first pressure value, the opening of the water supply buffer tank is opened, and the water in the steam-water pipeline flows back to the water supply buffer tank in a direction opposite to the first direction, until the mixing pressure of water and steam in the steam-water pipeline is lower than the first pressure value again.

2. The steam pressure stabilization system of the molten salt thermal storage steam generator as described in claim 1, characterized in that, The heat storage structure is a cylindrical molten salt storage tank, and the heat storage medium is molten salt including but not limited to binary or ternary salts.

3. The steam pressure stabilization system of the molten salt thermal storage steam generator as described in claim 1, characterized in that, The heat exchange structure extends along the height direction of the heat storage structure in a spiral arrangement.

4. The steam pressure stabilization system of the molten salt thermal storage steam generator as described in claim 1, characterized in that, The water supply pipeline is equipped with a check valve. The water supply pipeline and the opening of the water supply buffer tank form a junction node. The output end of the check valve is connected to the junction node of the water supply pipeline and the water supply buffer tank. The check valve is used to restrict the backflow of water in the steam-water pipeline to the water supply pipeline on the side of the input end of the check valve.

5. The steam pressure stabilization system of the molten salt thermal storage steam generator as described in claim 4, characterized in that, The water supply pipeline is equipped with a water supply valve, the output end of which is connected to the input end of the check valve. The water supply valve is used to regulate the flow rate of water supplied unidirectionally from the water supply pipeline to the steam-water pipeline.

6. The steam pressure stabilization system of the molten salt thermal storage steam generator as described in claim 5, characterized in that, The water supply pipeline is equipped with a water supply pump, the output end of which is connected to the input end of the water supply valve. The water supply pump is used to provide power for the water supply to flow in the water supply pipeline and the steam-water pipeline in the first direction.

7. The steam pressure stabilization system of the molten salt thermal storage steam generator as described in claim 1, characterized in that, It is also equipped with a steam pressure relief pipeline, the input end of which is connected to the steam pipeline, and the output end of which is connected to the liquid storage space of the water supply buffer tank; The steam pressure relief pipeline is equipped with a back pressure valve. The back pressure valve is configured such that when the steam pressure in the steam pipeline and the steam-water pipeline is lower than a preset second pressure value, the back pressure valve closes, and steam is output to the outside of the molten salt thermal storage steam generator along the steam pipeline. When the steam pressure in the steam pipeline and the steam-water pipeline is higher than the second pressure value, the back pressure valve opens, and part or all of the steam is output to the feedwater buffer tank along the steam pressure relief pipeline and condenses to form feedwater again.

8. The steam pressure stabilization system of the molten salt thermal storage steam generator as described in claim 7, characterized in that, The pressure range between the opening of the water supply buffer tank and the back pressure valve is manually set according to the applicable operating conditions of the molten salt thermal storage steam generator.

9. The steam pressure stabilization system of the molten salt thermal storage steam generator as described in claim 1, characterized in that, The outer wall of the heat storage structure is provided with a heat insulation layer.

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