Coupling heat storage boiler system, power generation system and reheat steam temperature adjusting method

Abstract

This invention provides a coupled thermal storage boiler system, a power generation system, and a method for regulating reheat steam temperature. The coupled thermal storage boiler system includes a furnace water-cooled wall, a superheated steam delivery pipeline, a superheater group, a thermal storage steam delivery pipeline, a reheat steam delivery pipeline, a reheater group, branch output pipelines, and a heat exchanger. A portion of the superheated steam in the superheated steam delivery pipeline can be delivered to the heat exchanger via the branch output pipelines, allowing the high-temperature superheated steam to heat the low-temperature thermal storage steam within the heat exchanger. This invention utilizes the heat from a portion of the high-temperature steam on the superheater side to heat the low-temperature steam on the reheater side. This method provides rapid heat transfer and flexible control over the high-temperature steam delivery rate. Compared to existing steam temperature regulation methods, the delay in reheat steam temperature regulation is significantly reduced, thereby improving the speed of reheat steam temperature regulation and enhancing the flexibility and rapid load change capability of the boiler system.

Description

Technical Field

[0001] This invention relates to the field of boiler system technology, and more specifically, to a coupled thermal storage boiler system, a power generation system, and a method for regulating reheat steam temperature. Background Technology

[0002] To improve the flexibility of coal-fired power units and meet peak-shaving requirements, coal-fired power plant boilers need to achieve rapid load change operation, especially rapid load increase. Due to the significant delays in the boiler's pulverizing and combustion systems, one of the current technical approaches for achieving rapid load increase in coal-fired boilers is to couple a thermal storage system. When the unit requires a rapid load increase, steam from the thermal storage system enters the boiler's reheat steam system as a rapid supplement to the boiler's heat.

[0003] Currently, coal-fired power generating units are mainly equipped with ultra-supercritical once-through boilers. The steam temperature control system of ultra-supercritical once-through boilers typically involves: superheated steam temperature regulation using the coal-water ratio; and reheat steam temperature regulation methods usually include: oscillating burners, flue gas dampers, flue gas recirculation, and excess air coefficient assistance. These reheat steam temperature regulation methods are used individually or in combination in actual engineering projects.

[0004] Practical engineering experience shows that when using a coal-to-water ratio for steam temperature regulation on the boiler superheater side, the response time is typically around 2 minutes. This is because coal combustion heat transfer has a lag, meaning water regulation generally has to wait for the coal combustion process. Furthermore, the aforementioned reheat steam temperature regulation methods, whether used individually or in combination, exhibit even greater delays compared to the coal-to-water ratio method. For example, the oscillating burner regulation method raises the furnace flame center, increasing the furnace outlet flue gas temperature and altering the ratio of radiative and convective heat transfer in the boiler. This increases the heat absorption of the reheater side's heating surface. However, the transfer of heat release from the flue gas side to heat absorption on the steam side requires a heat release-heat absorption time process, resulting in a significant delay. Similarly, the partitioned flue damper regulation method changes the ratio of flue gas passing through the low-temperature superheater and low-temperature reheater sides by altering the damper opening, increasing the heat absorption of the reheater side's heating surface and thus regulating the reheat steam temperature. Flue gas recirculation and adjusting the excess air coefficient operate on similar principles. They all require changes in the heat release and absorption of the superheater / reheater side heating surfaces to achieve steam temperature regulation, thus incurring significant delays. The average delay of these reheater temperature control methods is around 15 minutes, or even longer. When these steam temperature regulation methods are used in combination, in addition to the inherent delay of each method, further delays arise due to the coupling of these methods, resulting in an even greater delay in reheat steam temperature regulation. Therefore, it can be concluded that boiler superheater steam temperature regulation has a fast response time, while reheater steam temperature regulation has a very slow response time.

[0005] Currently, for thermal power units to achieve rapid load changes, boiler-coupled thermal storage systems (including molten salt thermal storage, solid thermal storage, or other media thermal storage systems) are an important technical means. However, this system has the following problems in actual engineering: The temperature level of the steam from the thermal storage system is still far below the rated temperature of the reheater outlet steam (for example, the outlet steam temperature of a ternary salt thermal storage system is about 360°C). This part of the thermal storage steam still needs to absorb heat again from the boiler reheater to reach the rated steam temperature at the reheater outlet (typically 623°C for ultra-supercritical boilers) before it can enter the turbine for power generation. After the medium-temperature steam from the thermal storage system is incorporated into the boiler reheat system, the boiler reheat steam flow rate increases compared to before coupling, and the heat absorption ratio of the boiler superheater / reheater (primary steam / secondary steam) changes significantly. At this time, it is necessary to use the boiler steam temperature regulation system to quickly regulate the reheat steam temperature. However, as mentioned earlier, the steam temperature response speed of the boiler reheat steam is relatively slow, with an average delay of about 15 minutes. Such a speed is difficult to meet the requirements of rapid load changes of current units. This can lead to a situation where, as the boiler load increases rapidly, the reheater outlet steam temperature lags significantly and fails to reach the rated value. This results in a decrease in the unit's economic efficiency during rapid load changes, and may even prevent the unit from achieving rapid load changes because the reheat steam temperature is too low to meet the turbine's steam inlet requirements. Summary of the Invention

[0006] This invention provides a coupled thermal storage boiler system, a power generation system, and a method for regulating the temperature of reheat steam, in order to solve the problem of slow temperature regulation of reheat steam in boiler systems with coupled thermal storage systems in the prior art.

[0007] To address the aforementioned problems, according to one aspect of the present invention, a coupled thermal storage boiler system is provided, comprising a furnace water-cooled wall, a superheated steam conveying pipeline, a superheater group, a thermal storage steam conveying pipeline, a reheated steam conveying pipeline, a reheater group, a branch output pipeline, and a heat exchanger; the furnace water-cooled wall, the superheated steam conveying pipeline, and the superheater group are sequentially connected, as are the thermal storage steam conveying pipeline, the heat exchanger, the reheated steam conveying pipeline, and the reheater group; wherein, the thermal storage steam conveying pipeline is used to convey thermal storage steam within the thermal storage system, the reheated steam conveying pipeline is used to convey reheated steam discharged from the high-pressure cylinder of the steam turbine, and the superheated steam conveying pipeline is connected to the heat exchanger via a branch output pipeline, wherein the superheated steam entering the heat exchanger heats the thermal storage steam entering the heat exchanger.

[0008] Furthermore, the heat exchanger has independent high-temperature and low-temperature zones, and the coupled thermal storage boiler system also includes branch return pipes and heating output pipes; wherein, the two ends of the branch output pipes are connected to the superheated steam conveying pipe and the inlet of the high-temperature zone, respectively; the two ends of the branch return pipes are connected to the outlet of the high-temperature zone and the superheater group, respectively; the outlet of the thermal storage steam conveying pipe is connected to the inlet of the low-temperature zone; and the two ends of the heating output pipe are connected to the outlet of the low-temperature zone and the reheated steam conveying pipe, respectively.

[0009] Furthermore, the coupled thermal storage boiler system also includes a flow distribution valve, the inlet of which is connected to the superheated steam delivery pipeline, the first outlet of which is connected to the inlet of the superheater group, and the second outlet of which is connected to the inlet of the branch output pipeline. The flow distribution valve is used to distribute the flow rate of superheated steam entering the superheater group and the heat exchanger. Alternatively, the coupled thermal storage boiler system also includes a throttling valve, which is installed on the branch output pipeline. The opening of the throttling valve is adjustable to regulate the flow rate of superheated steam entering the heat exchanger.

[0010] Furthermore, the coupled thermal storage boiler system also includes a control unit and a first monitoring component, a second monitoring component, a third monitoring component, and a fourth monitoring component for monitoring temperature and pressure; wherein, the first monitoring component is installed in the superheated steam conveying pipeline, the second monitoring component is installed in the superheater group, the third monitoring component is installed in the thermal storage steam conveying pipeline, and the fourth monitoring component is installed in the reheated steam conveying pipeline, and the fourth monitoring component is located downstream of the connection point between the heating output pipeline and the reheated steam conveying pipeline; the first monitoring component, the second monitoring component, the third monitoring component, and the fourth monitoring component are electrically connected to the control unit, and the flow distribution valve or throttling valve is electrically connected to the control unit.

[0011] Furthermore, the heat exchanger is a heat pipe heat exchanger, which includes a cylinder, a main pressure-bearing baffle, and multiple heat exchange tubes. The main pressure-bearing baffle is fixed inside the cylinder, and the periphery of the main pressure-bearing baffle is sealed to the inner wall of the cylinder. Multiple main openings are distributed on the main pressure-bearing baffle, and each heat exchange tube passes through a corresponding main opening. The heat exchange tube and the main pressure-bearing baffle are fixed and sealed. The high-temperature zone and the low-temperature zone are located on opposite sides of the main pressure-bearing baffle, with a portion of the heat exchange tube located in the high-temperature zone and a portion of the heat exchange tube located in the low-temperature zone. The heat exchange tube is filled with a phase-change heat transfer medium.

[0012] Furthermore, the heat exchanger also includes an auxiliary pressure-bearing structure, which is disposed inside the cylinder and fixedly connected to the inner wall of the cylinder. The auxiliary pressure-bearing structure is located on the side of the main pressure-bearing baffle facing the low-temperature zone. The auxiliary pressure-bearing structure cooperates with the main pressure-bearing baffle and / or heat exchange tubes to bear the pressure of superheated steam in the high-temperature zone that the main pressure-bearing baffle receives.

[0013] Furthermore, the auxiliary pressure-bearing structure includes an auxiliary pressure-bearing baffle, which is fixed inside the cylinder and its periphery is sealed to the inner wall of the cylinder; the auxiliary pressure-bearing baffle has multiple auxiliary openings, each heat exchange tube passes through a corresponding auxiliary opening, and the heat exchange tube and the auxiliary pressure-bearing baffle are fixedly connected.

[0014] Furthermore, the auxiliary pressure-bearing structure also includes multiple bellows, each bellows being fitted onto a heat exchange tube, with both ends of the bellows abutting against the auxiliary pressure-bearing baffle and the main pressure-bearing baffle, respectively; or, the auxiliary pressure-bearing structure also includes multiple compression springs, each compression spring being fitted onto a heat exchange tube, with both ends of the compression spring abutting against the auxiliary pressure-bearing baffle and the main pressure-bearing baffle, respectively.

[0015] Furthermore, both the auxiliary pressure-bearing baffle and the main pressure-bearing baffle are welded to the cylinder body, and both are welded to the heat exchange tubes; the area inside the cylinder located on the side of the auxiliary pressure-bearing baffle away from the main pressure-bearing baffle is a pressure balance zone; the auxiliary pressure-bearing baffle has balance holes, and the low-temperature zone is connected to the pressure balance zone through the balance holes; or, the heat exchanger also includes a pressure balance pipe located outside the cylinder body, and the low-temperature zone is connected to the pressure balance zone through the pressure balance pipe.

[0016] Furthermore, the outer surface of the heat exchange tube is provided with multiple heat exchange fins; and / or, the heat exchanger also includes a rectifier plate located inside the cylinder, the rectifier plate being fixedly connected to the inner wall of the cylinder, and the rectifier plate being parallel to the main pressure-bearing baffle, the area between the main pressure-bearing baffle and the rectifier plate forming a high-temperature zone.

[0017] Furthermore, the coupled thermal storage boiler system also includes a steam-water separator, with the furnace water-cooled wall, steam-water separator, and superheated steam delivery pipeline connected in sequence; the superheater group includes a primary superheater, a secondary superheater, and a high-temperature superheater connected in sequence, wherein the inlet of the primary superheater and the outlet of the superheated steam delivery pipeline are connected; the reheater group includes a low-temperature reheater and a high-temperature reheater connected in sequence, with the inlet of the low-temperature reheater and the outlet of the reheated steam delivery pipeline connected.

[0018] The present invention also provides a power generation system, which includes a thermal storage system, a steam turbine, and the above-mentioned coupled thermal storage boiler system. The steam outlet of the thermal storage system is connected to the thermal storage steam delivery pipeline, the outlet of the superheater group is connected to the inlet of the high-pressure cylinder of the steam turbine, the outlet of the high-pressure cylinder of the steam turbine is connected to the reheat steam delivery pipeline, and the outlet of the reheater group is connected to the intermediate-pressure cylinder and / or low-pressure cylinder of the steam turbine.

[0019] The present invention also provides a method for regulating reheat steam temperature, which is used in the above-mentioned coupled thermal storage boiler system. The method includes: transporting thermal storage steam from the thermal storage system to a heat exchanger via a thermal storage steam transport pipeline, and then inputting it into a reheat steam transport pipeline; obtaining the outlet steam temperature of the superheater group and the outlet steam temperature of the reheater group; when the outlet steam temperature of the superheater group is higher than the superheat rating and the outlet steam temperature of the reheater group is lower than the reheat rating, inputting a portion of the superheated steam into the heat exchanger via the superheated steam transport pipeline to heat the thermal storage steam entering the heat exchanger.

[0020] In this scheme, the superheated steam output from the furnace water-cooled wall is transported to the superheater group through a superheated steam transport pipeline. After being heated in the superheater group, the superheated steam becomes high-temperature and high-pressure superheated steam. The superheated steam is used to power the high-pressure cylinder of the turbine. The reheated steam discharged from the high-pressure cylinder of the turbine is transported to the reheated steam transport pipeline. The thermal storage steam transport pipeline can transport the thermal storage steam in the thermal storage system to the reheated steam transport pipeline. The thermal storage steam and reheated steam are mixed and then enter the reheater group. After being heated by the reheater group, they are transported to the intermediate-pressure cylinder or low-pressure cylinder of the turbine for power generation. The thermal storage steam transport pipeline can be opened or closed as needed, and is usually coupled with thermal storage steam when the system needs to rapidly increase the load. When the system needs to rapidly increase load, a portion of the superheated steam in the superheated steam delivery pipeline can be transported to the heat exchanger via a branch output pipeline. In this way, the high-temperature superheated steam heats the low-temperature stored heat steam within the heat exchanger. The heated stored heat steam is then transported to the reheat steam delivery pipeline. This allows the temperature of the mixed reheat steam entering the reheater group to rise rapidly, and the temperature of the steam output from the reheater group also rises rapidly, thus achieving rapid load increase for the system. Therefore, this scheme utilizes the heat from a portion of the high-temperature steam on the superheater side to heat the low-temperature steam on the reheater side. This method offers rapid heat transfer and flexible control over the amount of high-temperature steam delivered. Compared to existing technologies that regulate steam temperature by changing the heat release and absorption of the heating surfaces on the superheater / reheater side, the delay in reheat steam temperature regulation is significantly reduced, thereby improving the speed of reheat steam temperature regulation and enhancing the flexibility and rapid load change capability of the boiler system. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0022] Figure 1 A schematic diagram of a coupled thermal storage boiler system provided in an embodiment of the present invention is shown;

[0023] Figure 2A schematic diagram of a heat exchanger in a coupled thermal storage boiler system provided by an embodiment of the present invention is shown.

[0024] The above figures include the following reference numerals:

[0025] 11. Furnace water-cooled wall; 12. Superheated steam conveying pipeline; 13. Branch output pipeline; 14. Branch return pipeline; 15. Flow distribution valve; 16. Steam-water separator;

[0026] 20. Superheater assembly; 21. Primary superheater; 22. Secondary superheater; 23. High-temperature superheater;

[0027] 31. Thermal steam transmission pipeline; 32. Heating output pipeline;

[0028] 40. Reheat steam transmission pipeline;

[0029] 50. Reheater assembly; 51. Low-temperature reheater; 52. High-temperature reheater;

[0030] 60. Heat exchanger; 601. High temperature zone; 602. Low temperature zone; 603. Pressure balance zone; 61. Shell; 62. Main pressure-bearing baffle; 63. Heat exchange tube; 64. Auxiliary pressure-bearing baffle; 65. Bellows; 66. Pressure balance tube; 67. Rectifier plate; 68. Exhaust port; 69. Inspection door;

[0031] 71. Control unit; 72. First monitoring component; 73. Second monitoring component; 74. Third monitoring component; 75. Fourth monitoring component;

[0032] 80. Thermal storage system. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0034] like Figure 1 and Figure 2As shown, an embodiment of the present invention provides a coupled thermal storage boiler system, including a furnace water-cooled wall 11, a superheated steam conveying pipe 12, a superheater group 20, a thermal storage steam conveying pipe 31, a reheated steam conveying pipe 40, a reheater group 50, a branch output pipe 13, and a heat exchanger 60; the furnace water-cooled wall 11, the superheated steam conveying pipe 12, and the superheater group 20 are connected in sequence, and the thermal storage steam conveying pipe 31, the heat exchanger 60, the reheated steam conveying pipe 40, and the reheater group 50 are connected in sequence; wherein, the thermal storage steam conveying pipe 31 is used to convey thermal storage steam in the thermal storage system 80, the reheated steam conveying pipe 40 is used to convey reheated steam discharged from the high-pressure cylinder of the steam turbine, and the superheated steam conveying pipe 12 is connected to the heat exchanger 60 through the branch output pipe 13, and the superheated steam entering the heat exchanger 60 heats the thermal storage steam entering the heat exchanger 60.

[0035] In this scheme, the superheated steam output from the furnace water-cooled wall 11 is transported to the superheater group 20 through the superheated steam transport pipeline 12. After being heated in the superheater group 20, the superheated steam becomes high-temperature and high-pressure superheated steam. The superheated steam is used to input the high-pressure cylinder of the steam turbine for power generation. The reheated steam discharged from the high-pressure cylinder of the steam turbine is transported to the reheated steam transport pipeline 40. The thermal storage steam transport pipeline 31 can transport the thermal storage steam in the thermal storage system 80 to the reheated steam transport pipeline 40. After the thermal storage steam and reheated steam are mixed, they enter the reheater group 50. After being heated by the reheater group 50, they are transported to the intermediate-pressure cylinder or low-pressure cylinder of the steam turbine for power generation. The thermal storage steam transport pipeline 31 can be opened or closed as needed, and is usually coupled with thermal storage steam when the system needs to rapidly increase the load. When the system needs to rapidly increase its load, a portion of the superheated steam in the superheated steam delivery pipeline 12 can be delivered to the heat exchanger 60 via the branch output pipeline 13. This allows the high-temperature superheated steam to heat the low-temperature thermal storage steam within the heat exchanger 60. The heated thermal storage steam is then delivered to the reheated steam delivery pipeline 40, thus rapidly increasing the temperature of the mixed reheated steam entering the reheater group 50. Consequently, the temperature of the steam output from the reheater group 50 also increases rapidly, achieving rapid load increase for the system. Therefore, this scheme utilizes the heat from a portion of the high-temperature steam on the superheater side to heat the low-temperature steam on the reheater side. This method offers rapid heat transfer and flexible control over the high-temperature steam delivery rate. Compared to existing technologies that regulate steam temperature by altering the heat release and absorption of the superheater / reheater side heating surfaces, the delay in reheated steam temperature regulation is significantly reduced, thereby improving the speed of reheated steam temperature regulation and enhancing the boiler system's flexibility and rapid load change capability.

[0036] This technical solution addresses the problem that when a coal-fired unit with a coupled thermal storage system rapidly increases its load, the medium-temperature steam from the thermal storage system enters the boiler reheat system and couples with the original reheat system steam. Traditional reheat steam temperature regulation methods suffer from significant delays, leading to a severe lag in the reheater outlet steam temperature. This results in decreased unit economy during rapid load changes, and in some cases, even inoperability. In other words, this invention solves the problem of inconsistent response speeds between boiler superheater and reheater steam temperature regulation, thereby improving the unit's rapid load change capability. This invention is applicable not only to secondary reheat units but also to supercritical and ultra-supercritical primary reheat units. This invention improves the response speed of boiler reheat steam temperature regulation, solving the problem of significant delays in reheat steam temperature regulation during rapid load changes in current coal-fired boilers, thus enhancing the overall unit's rapid response capability and operational economy.

[0037] The heat exchanger 60 has an independent high-temperature zone 601 and a low-temperature zone 602. The coupled thermal storage boiler system also includes a branch return pipe 14 and a heating output pipe 32. The two ends of the branch output pipe 13 are connected to the superheated steam conveying pipe 12 and the inlet of the high-temperature zone 601, respectively. The two ends of the branch return pipe 14 are connected to the outlet of the high-temperature zone 601 and the superheater group 20, respectively. The outlet of the thermal storage steam conveying pipe 31 is connected to the inlet of the low-temperature zone 602, and the two ends of the heating output pipe 32 are connected to the outlet of the low-temperature zone 602 and the reheated steam conveying pipe 40, respectively.

[0038] In this way, superheated steam and stored heat steam enter the high-temperature zone 601 and the low-temperature zone 602 respectively. That is, the superheated steam and stored heat steam exchange heat but do not mix. The temperature drop of the superheated steam after heat exchange is relatively small. It is then transported to the superheater group 20 through the branch return pipe 14. After being heated in the superheater group 20, it enters the high-pressure cylinder of the turbine for power generation. This heat exchange method is particularly suitable for situations where the steam temperature output from the superheater group 20 is relatively high. This allows for full utilization of the heat on the superheater side without affecting the amount of superheated steam or the steam supply requirements of the turbine's high-pressure cylinder.

[0039] like Figure 1 As shown, the coupled thermal storage boiler system also includes a flow distribution valve 15. The inlet of the flow distribution valve 15 is connected to the superheated steam delivery pipe 12, the first outlet of the flow distribution valve 15 is connected to the inlet of the superheater assembly 20, and the second outlet of the flow distribution valve 15 is connected to the inlet of the branch output pipe 13. The flow distribution valve 15 is used to distribute the flow rate of superheated steam entering the superheater assembly 20 and the heat exchanger 60. Alternatively, in an embodiment not shown, the coupled thermal storage boiler system also includes a throttling valve installed on the branch output pipe 13. The opening degree of the throttling valve is adjustable to regulate the flow rate of superheated steam entering the heat exchanger 60.

[0040] Both of these methods allow for adjustment of the amount of superheated steam supplied to the heat exchanger 60, thus enabling flexible adjustment of the heating rate and temperature of the stored steam, and consequently, the temperature of the mixed reheated steam. This adjustment method exhibits low delay and fast response, thereby improving the load regulation capability of the boiler system.

[0041] In one specific embodiment, during the actual operation of the boiler system, when a rapid load increase is required, the thermal storage system 80 provides the boiler system with normally stored medium-temperature steam. The flow rate of superheated steam entering the heat exchanger 60 can be adjusted by changing the opening of the flow distribution valve 15, thereby changing the amount of heat absorbed by the thermal storage steam from the superheater side and altering the temperature of the thermal storage steam entering the reheater side. Essentially, this changes the proportion of heat absorbed by the boiler's reheater side, ultimately regulating the reheat steam temperature at the outlet of the reheater group 50. Since the superheater steam temperature is regulated by the coal-to-water ratio, and the heat exchanger 60 employs a heat pipe heat exchanger with high heat exchange efficiency and fast response speed, the medium-temperature steam from the thermal storage system can quickly "absorb" heat from the superheater side and provide it to the reheater side. This avoids the high delay problem associated with traditional reheat steam temperature regulation methods, facilitating rapid load changes in the system.

[0042] like Figure 1 As shown, the coupled thermal storage boiler system also includes a control unit 71 and a first monitoring component 72, a second monitoring component 73, a third monitoring component 74, and a fourth monitoring component 75 for monitoring temperature and pressure. The first monitoring component 72 is installed in the superheated steam transmission pipeline 12, the second monitoring component 73 is installed in the superheater group 20, the third monitoring component 74 is installed in the thermal storage steam transmission pipeline 31, and the fourth monitoring component 75 is installed in the reheated steam transmission pipeline 40, with the fourth monitoring component 75 located downstream of the connection point between the heating output pipeline 32 and the reheated steam transmission pipeline 40. The first monitoring component 72, the second monitoring component 73, the third monitoring component 74, and the fourth monitoring component 75 are electrically connected to the control unit 71, and the flow distribution valve 15 or the throttling valve is electrically connected to the control unit 71.

[0043] This allows for monitoring of steam temperature and pressure at multiple locations. On one hand, it monitors the temperature regulation range of the reheater group 50; on the other hand, it monitors the steam temperature in the superheated steam delivery pipeline 12. This ensures that the steam entering the superheater group 20 maintains a certain level of superheat, preventing water carryover due to a significant drop in superheat, thus avoiding water ingress into the superheater group 20. During the heating process, the temperature of the mixed reheated steam can be used to determine whether the appropriate temperature has been reached. Furthermore, the control unit 71 can adjust the opening of the flow distribution valve 15 or the throttle valve based on the temperature and pressure monitoring results, thereby adjusting the amount of superheated steam input to the heat exchanger 60 to regulate the heating rate and meet the heating requirements.

[0044] Furthermore, a shut-off valve is also installed on the superheated steam conveying pipeline 12, which facilitates the maintenance of the heat exchanger 60 or superheater group 20 downstream of the superheated steam conveying pipeline 12 and improves system safety.

[0045] In some embodiments, the heat exchanger 60 is a heat pipe heat exchanger, which includes a cylinder 61, a main pressure-bearing baffle 62, and a plurality of heat exchange tubes 63. The main pressure-bearing baffle 62 is fixed inside the cylinder 61, and the periphery of the main pressure-bearing baffle 62 is sealed to the inner wall of the cylinder 61. A plurality of main openings are distributed on the main pressure-bearing baffle 62, and each heat exchange tube 63 passes through a corresponding main opening. The heat exchange tube 63 and the main pressure-bearing baffle 62 are fixed and sealed to each other. The high-temperature zone 601 and the low-temperature zone 602 are located on opposite sides of the main pressure-bearing baffle 62, a portion of the heat exchange tube 63 is located in the high-temperature zone 601, and a portion of the heat exchange tube 63 is located in the low-temperature zone 602. The heat exchange tube 63 is filled with a phase change heat transfer medium.

[0046] The main pressure-bearing baffle 62 separates the high-temperature zone 601 and the low-temperature zone 602, and also serves to fix multiple heat exchange tubes 63. The temperature and pressure of the steam in the high-temperature zone 601 and the low-temperature zone 602 differ, creating a pressure difference between them. The main pressure-bearing baffle 62 also serves to bear the pressure. The portion of the heat exchange tube 63 located in the high-temperature zone 601 is the evaporation section, and the portion located in the low-temperature zone 602 is the condensation section. The evaporation section of the heat exchange tube 63 absorbs heat from the superheated steam and rapidly transfers it to the condensation section of the heat exchange tube 63 with minimal thermal resistance and no additional energy consumption through the latent heat of phase change circulation of the medium inside the heat exchange tube 63. The condensation section then transfers the heat to the stored steam, thus achieving rapid heating of the stored steam. This method offers high heat transfer efficiency and low energy loss, further improving the speed of temperature regulation of the reheated steam.

[0047] In one specific embodiment, superheated steam at approximately 460°C from the superheated steam transport pipe 12 enters the heat exchanger 60, laterally scouring the evaporation section of the heat exchange tube 63. Through forced convection, heat is transferred to the tube wall of the heat exchange tube 63. After releasing heat in the condensation section of the heat exchange tube 63, the superheated steam, with a temperature reduced to approximately 420-430°C, is input into the superheater assembly 20. The heat absorbed by the evaporation section is rapidly transferred to the condensation section with minimal thermal resistance and no additional energy consumption through the latent heat of phase change circulation of the internal working medium. Simultaneously, medium-temperature steam at approximately 360°C from the thermal storage steam transport pipe 31 enters the heat exchanger 60, laterally scouring the condensation section of the heat exchange tube 63. It absorbs the latent heat of phase change released from the tube wall, reaching a maximum temperature of 390°C, before being transported to the reheat steam transport pipe 40. There, it merges with the 360°C reheat steam within the reheat steam transport pipe 40, thereby increasing the overall temperature on the reheater side and regulating the reheat steam temperature.

[0048] The heat exchange tube 63 is made of 316L stainless steel. The working medium inside the heat exchange tube 63 can be liquid potassium metal or sodium-potassium alloy, etc. These two media have good chemical compatibility with 316L stainless steel, do not react significantly at high temperatures, are not prone to generating non-condensable gases, are safe and controllable, and are cost-effective for industrial applications. By controlling the amount of working medium filled, the pressure inside the heat exchange tube 63 can be controlled, so that the vaporization temperature of the working medium inside the heat exchange tube 63 is lower than the temperature of superheated steam, thereby achieving efficient heat exchange.

[0049] Furthermore, the heat exchanger 60 also includes an auxiliary pressure-bearing structure, which is disposed inside the cylinder 61 and fixedly connected to the inner wall of the cylinder 61. The auxiliary pressure-bearing structure is located on the side of the main pressure-bearing baffle 62 facing the low-temperature zone 602. The auxiliary pressure-bearing structure cooperates with the main pressure-bearing baffle 62 and / or the heat exchange tube 63 to bear the pressure of the superheated steam in the high-temperature zone 601 on the main pressure-bearing baffle 62.

[0050] By using an auxiliary pressure-bearing structure to assist the main pressure-bearing baffle 62 in bearing the pressure of superheated steam in the high-temperature zone 601, the pressure on the main pressure-bearing baffle 62 can be reduced, avoiding damage or leakage to the main pressure-bearing baffle 62, heat exchange tube 63 and other structures due to excessive pressure. This improves the safety of the heat exchanger 60 and solves the problem of easy leakage at the sealing points of structures such as heat exchange tube 63 under high pressure differential operating conditions.

[0051] Specifically, the auxiliary pressure-bearing structure includes an auxiliary pressure-bearing baffle 64, which is fixed inside the cylinder 61, and the periphery of the auxiliary pressure-bearing baffle 64 is sealed to the inner wall of the cylinder 61; the auxiliary pressure-bearing baffle 64 has multiple auxiliary openings, and each heat exchange tube 63 passes through a corresponding auxiliary opening, and the heat exchange tube 63 and the auxiliary pressure-bearing baffle 64 are fixedly connected.

[0052] In this way, a portion of the pressure from the superheated steam in the high-temperature zone 601 on the main pressure-bearing baffle 62 is transferred to the auxiliary pressure-bearing baffle 64 through multiple heat exchange tubes 63. Furthermore, the auxiliary pressure-bearing baffle 64 and the main pressure-bearing baffle 62 are arranged parallel to each other, and the area between the auxiliary pressure-bearing baffle 64 and the main pressure-bearing baffle 62 forms the high-temperature zone 601. The auxiliary pressure-bearing baffle 64 can rectify the superheated steam in the high-temperature zone 601, reduce steam flow resistance, and allow the superheated steam to fully contact the multiple heat exchange tubes 63, thereby improving heat exchange efficiency.

[0053] Furthermore, such as Figure 2As shown, the auxiliary pressure-bearing structure also includes multiple bellows 65, each bellows 65 being sleeved on a heat exchange tube 63. The two ends of the bellows 65 abut against the auxiliary pressure-bearing baffle 64 and the main pressure-bearing baffle 62, respectively. The bellows 65 can withstand a certain pressure in their axial direction. Through this arrangement, a portion of the pressure from the superheated steam in the high-temperature zone 601 of the main pressure-bearing baffle 62 can be transferred to the auxiliary pressure-bearing baffle 64 through the multiple bellows 65.

[0054] Optionally, multiple through holes are provided on the side wall of the bellows 65 to allow steam to enter the bellows 65 and exchange heat with the heat exchange tube 63. Alternatively, the bellows 65 contacts the heat exchange tube 63, thereby transferring the heat of the steam to the heat exchange tube 63.

[0055] Alternatively, in embodiments not shown, the auxiliary pressure-bearing structure further includes multiple compression springs, each sleeved on a heat exchange tube 63, with both ends of the compression springs abutting against the auxiliary pressure-bearing baffle 64 and the main pressure-bearing baffle 62, respectively. In this way, a portion of the pressure from the superheated steam in the high-temperature zone 601 on the main pressure-bearing baffle 62 can be transferred to the auxiliary pressure-bearing baffle 64 through the multiple compression springs, thereby reducing the pressure on the main pressure-bearing baffle 62.

[0056] Specifically, both the auxiliary pressure-bearing baffle 64 and the main pressure-bearing baffle 62 are welded to the cylinder 61, and both are welded to the heat exchange tubes 63. This welding method ensures reliable connection and provides a sealing effect. The area inside the cylinder 61 located on the side of the auxiliary pressure-bearing baffle 64 opposite to the main pressure-bearing baffle 62 is a pressure balance zone 603. The auxiliary pressure-bearing baffle 64 has balance holes, through which the low-temperature zone 602 connects to the pressure balance zone 603; alternatively, the heat exchanger 60 also includes a pressure balance pipe 66 located outside the cylinder 61, through which the low-temperature zone 602 connects to the pressure balance zone 603. Through this arrangement, the pressure in the pressure balance zone 603 and the low-temperature zone 602 is equal, thus preventing a pressure difference between the two sides of the auxiliary pressure-bearing baffle 64, preventing the auxiliary pressure-bearing baffle 64 from bearing additional pressure, and protecting the auxiliary pressure-bearing baffle 64.

[0057] In some embodiments, the outer surface of the heat exchange tube 63 is provided with a plurality of heat exchange fins, which increases the heat exchange area with the steam and thus further accelerates the heat exchange efficiency.

[0058] The heat exchanger 60 also includes a rectifier plate 67 located inside the cylinder 61. The rectifier plate 67 is fixedly connected to the inner wall of the cylinder 61, and the rectifier plate 67 is parallel to the main pressure-bearing baffle 62. The area between the main pressure-bearing baffle 62 and the rectifier plate 67 forms a high-temperature zone 601. In this way, the rectifier plate 67 can rectify the steam in the high-temperature zone 601, causing the steam to flow towards the area where the heat exchange tubes 63 are distributed. This allows the steam to fully contact and exchange heat with the heat exchange tubes 63, improving the heat exchange effect. There is a gap between the rectifier plate 67 and the inner wall of the cylinder 61, or the rectifier plate 67 has through holes. This ensures pressure balance on both sides of the rectifier plate 67, preventing the rectifier plate 67 from experiencing pressure differences.

[0059] In one specific embodiment, the high-temperature zone 601 inside the heat exchanger 60 is supplied with high-temperature and high-pressure superheated steam, typically at 31.0 MPa and approximately 460°C under rated load, while the low-temperature zone 602 is supplied with steam from the heat storage system 80 at a pressure of approximately 6.0 MPa and a temperature of approximately 360°C. This results in a pressure difference of approximately 25.0 MPa between the high-temperature zone 601 and the low-temperature zone 602. The high-temperature zone 601 and the low-temperature zone 602 are separated by a main pressure-bearing baffle 62. Although the main pressure-bearing baffle 62 is welded to the inner wall of the cylinder 61, the 25.0 MPa pressure difference on both sides can cause deformation of the main pressure-bearing baffle 62. If this deformation occurs, it can lead to weld failure and leakage at numerous welding / sealing points of the heat exchange tubes 63 on the main pressure-bearing baffle 62. This invention, by incorporating a bellows 65 or a compression spring, can withstand the large pressure difference from the main pressure-bearing baffle 62 and transfer the expansion force generated by this pressure difference to the auxiliary pressure-bearing baffle 64. Simultaneously, due to the pressure balancing pipe 66, the pressure on both sides of the auxiliary pressure-bearing baffle 64 is the same, both at 6.0 MPa, and it does not bear any pressure difference. The auxiliary pressure-bearing baffle 64 is welded to the inner wall of the cylinder 61, ensuring stable working pressure conditions and preventing leakage or weld breakage.

[0060] Optionally, a non-condensable gas venting port 68 is provided at the top of the heat exchange tube 63. After use, non-condensable gases inevitably accumulate inside the heat exchange tube 63. These gases cannot effectively participate in heat exchange, affecting the heat exchange efficiency of the heat exchange tube 63. Therefore, the venting port 68 allows the non-condensable gases to be extracted. The venting port 68 can be opened periodically to release the non-condensable gases. An inspection door 69 is provided on the cylinder 61 for easy maintenance of the internal structure.

[0061] Furthermore, at the end of the condensation section of heat exchange tube 63, a gas storage chamber with a volume of 5% to 8% of the inner cavity of heat exchange tube 63 is designed. The trace amounts of non-condensable gas generated during operation will automatically accumulate in the gas storage chamber under the impetus of the gaseous phase change medium flow. The exhaust port 68 is connected to the gas storage chamber. Optionally, the gas storage chamber is located within the pressure balance zone 603, so that the gas storage chamber does not affect the heat exchange in the low-temperature zone 602.

[0062] like Figure 1 As shown, the coupled thermal storage boiler system also includes a steam-water separator 16. The furnace water-cooled wall 11, the steam-water separator 16 and the superheated steam conveying pipeline 12 are connected in sequence. The steam-water separator 16 is used to separate the mixture of liquid water and superheated steam output from the furnace water-cooled wall 11. The separated superheated steam is input to the superheated steam conveying pipeline 12.

[0063] The superheater assembly 20 includes a primary superheater 21, a secondary superheater 22, and a high-temperature superheater 23 connected in sequence. The inlet of the primary superheater 21 is connected to the outlet of the superheated steam delivery pipe 12. In this way, the superheated steam is heated sequentially by the primary superheater 21, the secondary superheater 22, and the high-temperature superheater 23, so that the obtained superheated steam reaches the rated temperature to meet the power generation requirements of the steam turbine.

[0064] The reheater assembly 50 includes a low-temperature reheater 51 and a high-temperature reheater 52 connected in sequence. The inlet of the low-temperature reheater 51 is connected to the outlet of the reheat steam delivery pipeline 40. The reheat steam is heated sequentially by the low-temperature reheater 51 and the high-temperature reheater 52, so that the reheat steam reaches the required temperature to meet the power generation needs of the steam turbine.

[0065] In some embodiments not shown, the coupled thermal storage boiler system also includes an auxiliary branch pipe that transports a portion of the reheat steam from the reheat steam delivery pipe 40 to the heat exchanger 60. This allows the reheat steam to be heated by the superheated steam delivered to the heat exchanger 60. The heated reheat steam is then returned to the reheat steam delivery pipe 40 and then fed into the reheater assembly 50. This method achieves the heating of the reheater-side steam using a portion of the steam from the superheater side, with a fast response time, thereby improving the speed of reheat steam temperature regulation.

[0066] The present invention also provides a power generation system, which includes a thermal storage system 80, a steam turbine, and the above-mentioned coupled thermal storage boiler system. The steam outlet of the thermal storage system 80 is connected to the thermal storage steam transmission pipeline 31, the outlet of the superheater group 20 is connected to the inlet of the high-pressure cylinder of the steam turbine, the outlet of the high-pressure cylinder of the steam turbine is connected to the reheat steam transmission pipeline 40, and the outlet of the reheater group 50 is connected to the intermediate-pressure cylinder and / or low-pressure cylinder of the steam turbine.

[0067] When the system needs to rapidly increase its load, a portion of the superheated steam in the superheated steam delivery pipeline 12 can be delivered to the heat exchanger 60 via the branch output pipeline 13. This allows the high-temperature superheated steam to heat the low-temperature stored heat steam within the heat exchanger 60. The heated stored heat steam is then delivered to the reheated steam delivery pipeline 40, thus rapidly increasing the temperature of the mixed reheated steam entering the reheater group 50. Consequently, the temperature of the steam output from the reheater group 50 also increases rapidly, achieving rapid load increase for the system. Therefore, this scheme utilizes the heat from a portion of the high-temperature steam on the superheater side to heat the low-temperature steam on the reheater side. This method offers rapid heat transfer and flexible control over the high-temperature steam delivery rate. Compared to existing methods of steam temperature regulation, the delay in reheated steam temperature regulation is significantly reduced, thereby improving the speed of reheated steam temperature regulation and enhancing the system's flexibility and rapid load change capability.

[0068] The present invention also provides a method for regulating reheat steam temperature. The method is used in the above-mentioned coupled thermal storage boiler system. The method includes: transporting thermal storage steam from the thermal storage system 80 to the heat exchanger 60 via the thermal storage steam transmission pipeline 31, and then inputting it into the reheat steam transmission pipeline 40; obtaining the outlet steam temperature of the superheater group 20 and the outlet steam temperature of the reheater group 50; when the outlet steam temperature of the superheater group 20 is higher than the superheat rated value and the outlet steam temperature of the reheater group 50 is lower than the reheat rated value, the superheat steam transmission pipeline 12 inputs a portion of the superheated steam into the heat exchanger 60 to heat the thermal storage steam entering the heat exchanger 60.

[0069] This reheat steam temperature regulation method utilizes the heat from a portion of the high-temperature steam on the superheater side to heat the low-temperature steam on the reheater side. This method allows for rapid heat transfer and flexible control of the high-temperature steam delivery rate, significantly reducing the delay in reheat steam temperature regulation. This improves the reheat steam temperature regulation speed and enhances the system's flexibility and rapid load change capability.

[0070] Furthermore, when the coupled thermal storage boiler system experiences rapid load changes, the outlet steam temperatures of the superheater and reheater will vary depending on the operating conditions, resulting in the following situations, and the corresponding adjustment methods are explained below:

[0071] 1) The superheater outlet steam temperature is higher than the rated value, and the reheater outlet steam temperature is lower than the rated value.

[0072] Taking a 600MW ultra-supercritical boiler as an example: Under the operating condition of a boiler system coupled with the steam of the thermal storage system, the superheater steam flow rate is 1645t / h, the steam-water separator outlet temperature is 460℃, the superheater outlet temperature is 609℃ (exceeding the rated value of 605℃), the reheat steam flow rate is 1353t / h, the reheater inlet temperature is 350℃, the reheater outlet temperature is 615℃ (below the rated value of 623℃), the steam flow rate from the thermal storage system is 300t / h, and the temperature is 360℃. The thermal storage steam enters the reheater inlet, and the flow rate after mixing with the original inlet steam of the reheater is 1653t / h, and the temperature is 352℃. That is, after coupling with the thermal storage steam, the inlet temperature of the reheater group is 352℃.

[0073] The adjustment operation at this point is as follows: Open the flow distribution valve and adjust its opening degree to allow the steam portion with an outlet temperature of 460℃ from the steam-water separator to pass through the branch output pipe until the steam flow rate in the branch output pipe reaches 100t / h. At this time, the heat storage steam with a flow rate of 300t / h and a temperature of 360℃ "absorbs" heat from the superheater side through the heat pipe heat exchanger, raising its temperature to 403.5℃. It then mixes with the original reheater inlet steam. The mixed reheater inlet steam flow rate is 1653t / h, and the temperature has increased from the original 352℃ to 360℃, an increase of 8℃. According to the boiler design principles, it can be calculated that the increase in the reheater inlet steam temperature will correspondingly lead to an increase in the reheater outlet temperature, with the increase being basically consistent. That is, at this point, while maintaining a constant coal-water ratio, the reheater outlet temperature will increase from 615℃ to 623℃, reaching the rated value, and the steam temperature adjustment is successful.

[0074] The 100t / h steam from the branch output pipeline, after heating the thermal storage steam, has its temperature reduced to 420℃. This steam then mixes with the original steam from the steam-water separator, which has an outlet temperature of 460℃. The resulting flow rate remains 1645t / h, but the temperature has decreased to 458℃, a reduction of 2℃ from the original 460℃. Based on boiler design principles, it can be calculated that a 2℃ decrease in the steam-water separator temperature corresponds to a decrease of approximately 4℃ in the superheater outlet temperature, meaning the superheater outlet temperature drops from 609℃ to 605℃, reaching the rated value. Therefore, the steam temperature regulation is successful.

[0075] The steam temperature regulation process described above is a relatively "ideal" operating condition, merely an example to illustrate the working process of the regulation system of this invention. In actual engineering, the boundary conditions of boiler operation may deviate from the ideal condition, therefore it is necessary to combine the adjustment of the boiler's coal-water ratio with the steam temperature regulation. The coal-water ratio method for regulating steam temperature has a faster response speed, much faster than the current traditional reheater steam temperature regulation methods, so it can ultimately complete the steam temperature regulation of the boiler superheater under the time requirements of rapid load change conditions of the unit.

[0076] 2) The superheater outlet steam temperature is lower than the rated value, while the reheater outlet steam temperature is higher than the rated value.

[0077] At this point, the steam flow rate of the branch output pipe should be reduced by changing the opening of the flow distribution valve, thereby reducing the amount of heat "absorbed" by the heat storage steam from the superheater side through the heat pipe heat exchanger, lowering the reheater inlet steam temperature, and thus lowering the reheater outlet steam temperature.

[0078] 3) The superheater outlet steam temperature is higher than the rated value, and the reheater outlet steam temperature is higher than the rated value.

[0079] This situation indicates that the total heat input to the boiler system is too high. The first step should be to reduce the coal-water ratio to decrease the total heat input to the boiler system. Then, depending on the specific circumstances, adjustments can be made using either method 1) or 2).

[0080] 4) The superheater outlet steam temperature is equal to the rated value, and the reheater outlet steam temperature is higher than the rated value.

[0081] This situation indicates that the total heat input to the boiler system is too high. The first step should be to reduce the coal-water ratio to decrease the total heat input to the boiler system. Then, depending on the specific circumstances, adjustments can be made using either method 1) or 2).

[0082] 5) The superheater outlet steam temperature is lower than the rated value, and the reheater outlet steam temperature is lower than the rated value.

[0083] This situation indicates that the total heat input of the boiler system is insufficient. The first step should be to increase the coal-water ratio to increase the total heat input of the boiler system. Then, depending on the specific situation, adjustments should be made according to either method 1) or 2).

[0084] 6) The superheater outlet steam temperature is equal to the rated value, and the reheater outlet steam temperature is lower than the rated value.

[0085] This situation indicates that the total heat input of the boiler system is insufficient. The first step should be to increase the coal-water ratio to increase the total heat input of the boiler system. Then, depending on the specific situation, adjustments should be made according to either method 1) or 2).

[0086] Compared to existing solutions, this invention reconstructs the boiler steam-water system coupled with the boiler steam temperature regulation method, coupling the steam temperature regulation methods of the thermal storage system, reheat system, and superheater system. It employs a heat pipe heat exchanger, where heat transfer relies on phase change (liquid → steam → liquid) rather than molecular heat conduction from metals like copper or iron. The heat pipe has an extremely high equivalent thermal conductivity, far exceeding that of metals. Simultaneously, the heat pipe heat exchanger has a fast response speed, achieving almost instantaneous heat conduction, allowing heat to be quickly transferred from the hot end to the cold end without significant lag. This solution enables rapid regulation of the thermal storage steam temperature, thereby achieving rapid regulation of the reheater inlet steam temperature. This meets the rapid response requirements of the reheater outlet steam temperature during rapid load changes, solving the technical problems of high delay (average delay of about 15 minutes) and slow response speed in existing boiler systems' reheater steam temperature regulation methods. Furthermore, it enables synchronous regulation of the superheater and reheater outlet steam temperatures, reducing the lifespan loss of high-temperature heat exchange elements during rapid load changes and improving the economic efficiency of unit operation.

[0087] The technical solution provided by this invention has at least the following technical effects:

[0088] 1. By utilizing the rapid heat exchange between a portion of the high-temperature steam at the boiler superheater inlet and the medium-temperature steam from the thermal storage system, the temperature of the medium-temperature steam in the thermal storage system can be controlled by changing the flow rate of the high-temperature steam at the superheater inlet.

[0089] 2. The temperature of the medium-temperature steam from the thermal storage system is controlled by adjusting the amount of heat it absorbs from the superheater system, and then mixing it with the inlet steam of the reheater group to change the temperature of the steam entering the reheater group, thereby regulating the outlet steam temperature of the reheater group.

[0090] 3. The phase change heat transfer method of heat pipe heat exchanger has the characteristics of high heat exchange efficiency and fast response, which enables the boiler superheater and reheater to realize the steam temperature regulation of coal-water ratio simultaneously, realize the rapid regulation of reheat steam temperature, and solve the technical problem that the existing reheater temperature regulation method has an average delay of about 15 minutes.

[0091] 4. Heat pipe heat exchangers solve the technical problem of leakage at the weld / seal joints of heat exchange tubes caused by excessive pressure difference between superheated steam and stored steam by setting two baffles to separate different areas, corrugated pipes surrounding the heat exchange tubes, and pressure balancing pipes.

[0092] The above descriptions are merely some embodiments of this solution and are not intended to limit the solution. Various modifications and variations can be made to this solution by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this solution should be included within the scope of protection of this solution.

[0093] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0094] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as exemplary only and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0095] In the description of this solution, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the attached drawings. It is only for the convenience of describing this solution and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or component referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this solution. The directional terms "inner" and "outer" refer to the inner and outer contours of each component itself.

[0096] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0097] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this solution.

Claims

1. A coupled thermal storage boiler system, characterized in that, It includes a furnace water-cooled wall (11), a superheated steam conveying pipe (12), a superheater group (20), a thermal storage steam conveying pipe (31), a reheated steam conveying pipe (40), a reheater group (50), a branch output pipe (13), and a heat exchanger (60); the furnace water-cooled wall (11), the superheated steam conveying pipe (12), and the superheater group (20) are connected in sequence, and the thermal storage steam conveying pipe (31), the heat exchanger (60), the reheated steam conveying pipe (40), and the reheater group (50) are connected in sequence; wherein, The thermal storage steam conveying pipeline (31) is used to convey thermal storage steam in the thermal storage system (80), the reheat steam conveying pipeline (40) is used to convey reheat steam discharged from the high-pressure cylinder of the steam turbine, the superheated steam conveying pipeline (12) is connected to the heat exchanger (60) through the branch output pipeline (13), and the superheated steam entering the heat exchanger (60) heats the thermal storage steam entering the heat exchanger (60).

2. The coupled thermal storage boiler system according to claim 1, characterized in that, The heat exchanger (60) has independent high-temperature zone (601) and low-temperature zone (602), and the coupled thermal storage boiler system further includes a branch return pipe (14) and a heating output pipe (32); wherein, The two ends of the branch output pipe (13) are respectively connected to the superheated steam conveying pipe (12) and the inlet of the high temperature zone (601). The two ends of the branch return pipe (14) are respectively connected to the outlet of the high temperature zone (601) and the superheater group (20). The outlet of the heat storage steam conveying pipe (31) is connected to the inlet of the low temperature zone (602). The two ends of the heating output pipe (32) are respectively connected to the outlet of the low temperature zone (602) and the reheat steam conveying pipe (40).

3. The coupled thermal storage boiler system according to claim 2, characterized in that, The coupled thermal storage boiler system also includes a flow distribution valve (15), the inlet of which is connected to the superheated steam conveying pipeline (12), the first outlet of which is connected to the inlet of the superheater group (20), and the second outlet of which is connected to the inlet of the branch output pipeline (13). The flow distribution valve (15) is used to distribute the flow rate of superheated steam input to the superheater group (20) and the heat exchanger (60). Alternatively, the coupled thermal storage boiler system may further include a throttling valve installed on the branch output pipe (13), the opening of which is adjustable to regulate the flow rate of superheated steam input to the heat exchanger (60).

4. The coupled thermal storage boiler system according to claim 3, characterized in that, The coupled thermal storage boiler system further includes a control unit (71) and a first monitoring component (72), a second monitoring component (73), a third monitoring component (74), and a fourth monitoring component (75) for monitoring temperature and pressure; wherein, The first monitoring component (72) is installed in the superheated steam conveying pipeline (12), the second monitoring component (73) is installed in the superheater group (20), the third monitoring component (74) is installed in the heat storage steam conveying pipeline (31), and the fourth monitoring component (75) is installed in the reheat steam conveying pipeline (40). The fourth monitoring component (75) is located downstream of the connection position between the heating output pipeline (32) and the reheat steam conveying pipeline (40). The first monitoring component (72), the second monitoring component (73), the third monitoring component (74) and the fourth monitoring component (75) are electrically connected to the control unit (71) respectively. The flow distribution valve (15) or the throttling valve is electrically connected to the control unit (71).

5. The coupled thermal storage boiler system according to claim 2, characterized in that, The heat exchanger (60) is a heat pipe heat exchanger. The heat exchanger (60) includes a cylinder (61), a main pressure-bearing baffle (62), and a plurality of heat exchange tubes (63). The main pressure-bearing baffle (62) is fixed inside the cylinder (61), and the periphery of the main pressure-bearing baffle (62) is sealed to the inner wall of the cylinder (61). A plurality of main openings are distributed on the main pressure-bearing baffle (62), and each heat exchange tube (63) passes through a corresponding main opening. The heat exchange tube (63) and the main pressure-bearing baffle (62) are fixed and sealed to each other. The high-temperature zone (601) and the low-temperature zone (602) are located on opposite sides of the main pressure-bearing baffle (62). A portion of the heat exchange tube (63) is located in the high-temperature zone (601), and a portion of the heat exchange tube (63) is located in the low-temperature zone (602). The heat exchange tube (63) is filled with a phase change heat transfer medium.

6. The coupled thermal storage boiler system according to claim 5, characterized in that, The heat exchanger (60) further includes an auxiliary pressure-bearing structure, which is disposed inside the cylinder (61) and fixedly connected to the inner wall of the cylinder (61). The auxiliary pressure-bearing structure is located on the side of the main pressure-bearing baffle (62) facing the low-temperature zone (602). The auxiliary pressure-bearing structure cooperates with the main pressure-bearing baffle (62) and / or the heat exchange tube (63) to bear the pressure of the superheated steam in the high-temperature zone (601) on the main pressure-bearing baffle (62).

7. The coupled thermal storage boiler system according to claim 6, characterized in that, The auxiliary pressure-bearing structure includes an auxiliary pressure-bearing baffle (64), which is fixed inside the cylinder (61), and the periphery of the auxiliary pressure-bearing baffle (64) is sealed to the inner wall of the cylinder (61); the auxiliary pressure-bearing baffle (64) has multiple auxiliary openings distributed on it, and each heat exchange tube (63) passes through a corresponding auxiliary opening, and the heat exchange tube (63) and the auxiliary pressure-bearing baffle (64) are fixedly connected.

8. The coupled thermal storage boiler system according to claim 7, characterized in that, The auxiliary pressure-bearing structure also includes multiple corrugated pipes (65), each corrugated pipe (65) being sleeved on one of the heat exchange tubes (63), and the two ends of the corrugated pipe (65) abutting against the auxiliary pressure-bearing baffle (64) and the main pressure-bearing baffle (62) respectively. Alternatively, the auxiliary pressure-bearing structure may also include multiple compression springs, each of which is sleeved on one of the heat exchange tubes (63), and the two ends of the compression springs abut against the auxiliary pressure-bearing partition (64) and the main pressure-bearing partition (62), respectively.

9. The coupled thermal storage boiler system according to claim 7, characterized in that, The auxiliary pressure-bearing baffle (64) and the main pressure-bearing baffle (62) are both welded to the cylinder (61), and the auxiliary pressure-bearing baffle (64) and the main pressure-bearing baffle (62) are both welded to the heat exchange tube (63); the area inside the cylinder (61) located on the side of the auxiliary pressure-bearing baffle (64) away from the main pressure-bearing baffle (62) is a pressure balance zone (603); the auxiliary pressure-bearing baffle (64) has a balance hole, and the low-temperature zone (602) is connected to the pressure balance zone (603) through the balance hole; or, the heat exchanger (60) further includes a pressure balance pipe (66) located outside the cylinder (61), and the low-temperature zone (602) is connected to the pressure balance zone (603) through the pressure balance pipe (66).

10. The coupled thermal storage boiler system according to claim 5, characterized in that, The outer surface of the heat exchange tube (63) is provided with a plurality of heat exchange fins; and / or, the heat exchanger (60) further includes a rectifier plate (67) located inside the cylinder (61), the rectifier plate (67) being fixedly connected to the inner wall of the cylinder (61), and the rectifier plate (67) being parallel to the main pressure-bearing baffle (62), the area between the main pressure-bearing baffle (62) and the rectifier plate (67) forming the high-temperature zone (601).

11. The coupled thermal storage boiler system according to claim 1, characterized in that, The coupled thermal storage boiler system also includes a steam-water separator (16), and the furnace water-cooled wall (11), the steam-water separator (16), and the superheated steam conveying pipeline (12) are connected in sequence; The superheater group (20) includes a primary superheater (21), a secondary superheater (22) and a high-temperature superheater (23) connected in sequence, wherein the inlet of the primary superheater (21) is connected to the outlet of the superheated steam conveying pipe (12); The reheater group (50) includes a low-temperature reheater (51) and a high-temperature reheater (52) connected in sequence, with the inlet of the low-temperature reheater (51) connected to the outlet of the reheat steam conveying pipeline (40).

12. A power generation system, characterized in that, The power generation system includes a thermal storage system (80), a steam turbine, and a coupled thermal storage boiler system as described in any one of claims 1 to 11. The steam outlet of the thermal storage system (80) is connected to the thermal storage steam transmission pipeline (31), the outlet of the superheater group (20) is connected to the inlet of the high-pressure cylinder of the steam turbine, the outlet of the high-pressure cylinder of the steam turbine is connected to the reheat steam transmission pipeline (40), and the outlet of the reheater group (50) is connected to the intermediate-pressure cylinder and / or low-pressure cylinder of the steam turbine.

13. A method for regulating the temperature of reheat steam, characterized in that, The reheat steam temperature regulation method is used in the coupled thermal storage boiler system according to any one of claims 1 to 11, wherein the reheat steam temperature regulation method includes: The thermal storage steam transport pipeline (31) transports the thermal storage steam from the thermal storage system (80) to the heat exchanger (60), and then inputs it into the reheat steam transport pipeline (40). Obtain the outlet steam temperature of the superheater group (20) and the outlet steam temperature of the reheater group (50); When the outlet steam temperature of the superheater group (20) is higher than the superheat rating and the outlet steam temperature of the reheater group (50) is lower than the reheat rating, the superheated steam conveying pipe (12) inputs a portion of the superheated steam into the heat exchanger (60) to heat the stored steam entering the heat exchanger (60).

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