Heat removal and supply system for deep peak regulation of thermal power generating unit and operation method

Abstract

The invention discloses a heat removal and supply system for deep peak regulation of a thermal power generating unit and an operation method. The system comprises a boiler, a steam turbine module, a high-pressure heater, a deaerator, a low-pressure heater, a condenser, a fused salt heat exchange system and a steam-water heat exchanger. The boiler is connected with a steam turbine high-pressure cylinder through a main steam pipeline and connected with a steam turbine intermediate-pressure cylinder through a reheat steam pipeline, and the steam turbine module is connected with a high-pressure heater and a low-pressure heater through a steam extraction pipeline. The reheated steam extraction pipeline conveys reheated steam to the steam-molten salt heat exchanger for heat exchange, and a non-condensed gas outlet of the steam-molten salt heat exchanger is connected with the steam-water heat exchanger through a non-condensed gas pipeline and used for waste heat recovery. The condenser is communicated with the low-pressure heater and the steam-water heat exchanger through pipelines, and condensate water circulation is achieved. The system can realize graded utilization of steam heat energy and stepped recovery of waste heat, improves the heat supply performance of the thermal power generating unit, and is suitable for a thermal power operation scene with load change.

Description

Technical Field

[0001] The present application relates to the field of thermal power generation technology, and in particular to a heat extraction and supply system and an operation method for deep peak regulation of a thermal power unit. Background Art

[0002] Thermal power units are an important part of the modern energy system, and their thermal energy utilization efficiency directly affects the economy and environmental protection of electricity and heating. By utilizing high-temperature steam in the turbine in stages and combining it with extraction heating technology, thermal power units can achieve cogeneration of heat and power, providing stable power output for the power grid while meeting regional heating needs. In recent years, in order to further improve energy utilization efficiency, more and more thermal power units have introduced molten salt heat exchange technology, using the high heat capacity characteristics of molten salt to achieve thermal energy storage and release, and meet the changing heating needs.

[0003] In the existing thermal power unit heat extraction and heating system, molten salt heat exchange technology is mainly used to store excess heat energy during low-load stages and release heat during peak heat demand. However, in traditional designs, the connection path between the molten salt heat exchanger and the heating network is relatively simple, and heat energy is usually transferred to the heating network after passing through a boiler or other intermediate links. This heat transfer method not only has a slow response speed, which can easily lead to insufficient heat supply during peak heat demand, but may also increase heat transfer losses and reduce the overall operating efficiency of the system.

[0004] In the existing thermal power unit heat extraction and heating system, the heat released by the molten salt heat exchanger during the peak heating period needs to pass through the boiler or other complex paths to enter the heating network, which limits the direct and efficient use of heat. Due to the low efficiency of the dynamic connection between the molten salt heat exchange system and the heating network, the system cannot respond quickly to changes in the heating load, affecting the heating performance. Therefore, how to optimize the connection between the molten salt heat exchanger and the heating network so that it can directly and efficiently transfer heat to the heating network during the peak heating period is a key problem that needs to be solved in the existing technology. Summary of the invention

[0005] The present application provides a heat extraction and heating system and an operation method for deep peak regulation of a thermal power unit, which are used to solve the problem in the prior art that the dynamic connection efficiency between the molten salt heat exchange device and the heating network is low and it is difficult to quickly respond to the peak of heating.

[0006] The technical solutions adopted in this application are as follows: On the one hand, the present application provides a heat extraction and heating system for deep peak regulation of a thermal power unit, comprising a boiler, a steam turbine module, a high-pressure heater, a deaerator, a low-pressure heater, a condenser, a molten salt heat exchange system and a steam-water heat exchanger; The steam turbine module includes a steam turbine high-pressure cylinder, a steam turbine intermediate-pressure cylinder and a steam turbine low-pressure cylinder. The boiler is used to generate high-temperature and high-pressure steam. The boiler is connected to the steam turbine high-pressure cylinder through a main steam pipeline. The boiler is also connected to the steam turbine intermediate-pressure cylinder through a reheat steam pipeline. A reheat steam extraction pipeline is provided on the reheat steam pipeline. The output end of the reheat steam extraction pipeline is connected to the steam inlet of the steam-molten salt heat exchanger to transfer the thermal energy of the steam to the molten salt. The steam-molten salt heat exchanger is provided with a non-condensable gas outlet and is connected to a first non-condensable gas pipeline. The non-condensable gas outlet of the steam-molten salt heat exchanger is connected to the steam-water heat exchanger through the first non-condensable gas pipeline to transport the uncondensed steam to the steam-water heat exchanger for reuse. The steam turbine high-pressure cylinder is connected to the reheater inlet of the boiler through a first exhaust pipe, and the steam turbine intermediate-pressure cylinder is connected to the steam inlet of the steam turbine low-pressure cylinder through a second exhaust pipe. The low-pressure cylinder of the steam turbine is connected to the condenser through a third exhaust steam pipe, and the outlet of the condenser is connected to the low-pressure heater via a condensate pump. The high-pressure cylinder of the steam turbine is connected to a first extraction steam pipe, the intermediate-pressure cylinder of the steam turbine is connected to a second extraction steam pipe, and the low-pressure cylinder of the steam turbine is connected to a third extraction steam pipe. The high-pressure cylinder of the steam turbine and the intermediate-pressure cylinder of the steam turbine are respectively connected to the extraction steam inlet of the high-pressure heater through the first extraction steam pipe and the second extraction steam pipe, the low-pressure cylinder of the steam turbine is connected to the extraction steam inlet of the low-pressure heater through the third extraction steam pipe, the first outlet feed water pipe of the high-pressure heater is connected to the superheater inlet of the boiler, and the intermediate-pressure cylinder of the steam turbine is also connected to a fourth exhaust steam pipe, the intermediate-pressure cylinder of the steam turbine is connected to the extraction steam inlet of the deaerator through the fourth exhaust steam pipe, the high-pressure heater is connected to the extraction steam inlet of the deaerator through the first drain pipe, and the low-pressure heater is connected to the extraction steam inlet of the deaerator through the second outlet feed water pipe.

[0007] In an optional embodiment, the molten salt heat exchange system includes a steam-molten salt heat exchanger, a molten salt hot tank, a molten salt cold tank and a molten salt-feed water heat exchanger, the molten salt output end of the molten salt-feed water heat exchanger is connected to the input end of the molten salt cold tank through a pipeline, the output end of the molten salt cold tank is connected to the molten salt input end of the steam-molten salt heat exchanger through a pipeline, the molten salt output end of the steam-molten salt heat exchanger is connected to the input end of the molten salt hot tank through a pipeline, and the output end of the molten salt hot tank is connected to the molten salt input end of the molten salt-feed water heat exchanger through a pipeline; the outlet water feed pipe of the deaerator is respectively connected to the high-pressure heater and the molten salt-feed water heat exchanger through a feed water pump, the heating water outlet of the molten salt-feed water heat exchanger is connected to a heating water supply pipe, and the heating water outlet of the molten salt-feed water heat exchanger is connected to the first outlet feed water pipe through the heating water supply pipe to transport the heated feed water in the molten salt-feed water heat exchanger to the boiler.

[0008] In an optional embodiment, a pressure reducing valve is provided on the reheat steam extraction pipeline.

[0009] In an optional embodiment, the low-pressure heater is connected to the condenser via a second drain pipe, the steam-water heat exchanger is provided with a non-condensable gas outlet and is connected to a second non-condensable gas pipe, and the non-condensable gas outlet of the steam-water heat exchanger is connected to the condenser via the second non-condensable gas pipe.

[0010] In an optional embodiment, the steam-water heat exchanger is connected to the deaerator through a drain return pipe.

[0011] In an optional embodiment, a pressure water pump is provided on the drain return pipe, and the steam-water heat exchanger is also connected to a normal-pressure water pump. The inlet of the normal-pressure water pump is connected to a normal-pressure water source, and the outlet of the normal-pressure water pump is connected to the water input end of the steam-water heat exchanger through a pipe, so as to transport normal-pressure water to the steam-water heat exchanger.

[0012] In an optional embodiment, the steam-water heat exchanger is connected to the heating network via a heating pipeline.

[0013] In an optional embodiment, the steam-molten salt heat exchanger adopts a spiral coil heat exchange structure to improve heat transfer efficiency.

[0014] In an optional embodiment, a heating bypass pipe is connected to the heating water supply pipe, the heating bypass pipe is connected to the heating supply pipe, and a regulating valve is provided on the heating bypass pipe.

[0015] On the other hand, the present application also provides an operation method of a heat extraction and heating system for deep peak regulation of a thermal power unit, which is applied to the heat extraction and heating system for deep peak regulation of a thermal power unit provided in the present application, and the operation method includes: a. Steam cycle process: a1. The high-temperature and high-pressure steam generated by the boiler is transported to the high-pressure cylinder of the steam turbine through the main steam pipeline; a2. The steam discharged from the high-pressure cylinder of the steam turbine enters the reheater of the boiler through the first exhaust steam pipe for reheating to form reheated steam; a3. The reheated steam is transported to the intermediate pressure cylinder of the steam turbine through the reheated steam pipeline, and the steam discharged from the intermediate pressure cylinder of the steam turbine is transported to the low pressure cylinder of the steam turbine through the second exhaust steam pipeline; a4. The steam discharged from the low-pressure cylinder of the steam turbine is transported to the condenser through the third exhaust pipe for cooling and recovery; b. Molten salt heat exchange cycle process: b1. The reheated steam is introduced into the steam-molten salt heat exchanger through the reheated steam extraction pipeline to transfer heat energy to the molten salt; b2. The uncondensed steam in the steam-molten salt heat exchanger is transported to the steam-water heat exchanger through the non-condensable gas outlet and the first non-condensable gas pipeline to further utilize the waste heat; b3. The heated molten salt is transported to the molten salt-feed water heat exchanger through the molten salt hot tank to transfer the heat to the feed water; b4. The cooled molten salt returns to the steam-molten salt heat exchanger through the molten salt cold tank to complete the molten salt closed-loop circulation; c. Water supply cycle process: c1. The deaerator deoxygenates the feed water, and the treated feed water is transported to the high-pressure heater and the molten salt-feed water heat exchanger through the feed water pump; c2. The feed water heated in the molten salt-feed water heat exchanger is transported to the superheater inlet of the boiler through the heating water supply pipeline for further heating; c3. During the peak heating period, part of the heated feed water is directly transported to the heating pipeline through the heating bypass pipeline to meet the heating demand; c4. The drain generated in the steam-water heat exchanger is transported to the deaerator through the drain return pipe to complete the closed-loop circulation.

[0016] Compared with the prior art, this application has the following beneficial effects: 1. The heat extraction and heating system for deep peak regulation of thermal power units provided in this application, through the reheat steam pipeline, directly transports the reheated steam of the boiler to the steam inlet of the steam-molten salt heat exchanger through the reheat steam extraction pipeline, which can realize the direct transfer of steam heat to the molten salt. This design eliminates the complex path in which the steam heat needs to be transferred through multiple stages of equipment in the traditional system, and can reduce the loss of heat during the transfer process. At the same time, the reheat steam pipeline connects the boiler and the steam turbine intermediate pressure cylinder, which is used to transport reheated steam to the steam turbine intermediate pressure cylinder, and the reheat steam extraction pipeline is connected to the reheat steam pipeline, which can directly introduce part of the reheated steam into the steam-molten salt heat exchanger, so as to realize the efficient transfer of reheated steam heat energy. Through this connection method, the steam-molten salt heat exchanger can receive high-temperature reheated steam from the boiler, providing a stable source of heat energy for molten salt heat exchange.

[0017] 2. The steam-molten salt heat exchanger of the present application is provided with a non-condensable gas outlet and connected to the steam-water heat exchanger through a first non-condensable gas pipeline. The steam that is not completely condensed can enter the steam-water heat exchanger for secondary heat transfer, and the waste heat is further recovered to the heating network. This design method can solve the problem of non-condensable steam being directly discharged in the prior art, and extend the heat transfer path through reasonable layout. Moreover, through the multiple utilization of non-condensable steam, the overall heat energy recovery capacity of the system can be significantly improved, while reducing heat loss, providing a more stable heat source support for the heating network.

[0018] 3. This application establishes an orderly connection between the boiler, the turbine module and the steam-molten salt heat exchanger through the main steam pipe, the reheat steam pipe and the reheat steam extraction pipe. After the steam is released in stages from the high-pressure cylinder of the turbine and the intermediate-pressure cylinder of the turbine, a portion of the reheated steam enters the molten salt heat exchange system through the reheat steam extraction pipe, where the steam-molten salt heat exchanger completes the transfer of heat to the molten salt. This design enables the molten salt heat exchange system to dynamically access the entire heating process, reducing the intermediate steps required for heat transfer from steam to the heating system, shortening the heat transfer time, and this application can achieve efficient coordination with the heating network through the reasonable layout of the molten salt heat exchange system, thereby improving the problem of slow heating response caused by inflexible heat distribution in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 A schematic diagram of a heat extraction and heating system for deep peak regulation of a thermal power unit provided in one embodiment of the present application; Figure 2 A schematic diagram of a heat extraction and heating system for deep peak regulation of a thermal power unit provided in another embodiment of the present application; Figure 3 A schematic diagram of a heat extraction and supply system for deep peak regulation of a thermal power unit provided in yet another embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application is clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work also fall within the scope of protection of the present application.

[0022] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0023] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0024] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0025] See also Figure 1-Figure 3 The embodiment of the present application provides a heat extraction and heating system for deep peak regulation of a thermal power unit, including a boiler 100, a turbine module 200, a high-pressure heater 300, a deaerator 400, a low-pressure heater 500, a condenser 600, a molten salt heat exchange system 700 and a steam-water heat exchanger 800.

[0026] Among them, the turbine module 200 includes a turbine high-pressure cylinder 210, a turbine intermediate-pressure cylinder 220 and a turbine low-pressure cylinder 230. The boiler 100 is used to generate high-temperature and high-pressure steam. The boiler 100 is connected to the turbine high-pressure cylinder 210 through a main steam pipe 101. The boiler 100 is also connected to the turbine intermediate-pressure cylinder 220 through a reheat steam pipe 102. A reheat steam extraction pipe 103 is connected to the reheat steam pipe 102. The output end of the reheat steam extraction pipe 103 is connected to the steam inlet of the steam-molten salt heat exchanger 710 to transfer the thermal energy of the steam to the molten salt.

[0027] At the same time, in order to solve the problem in the prior art that the waste heat after steam heat exchange is often not fully utilized, resulting in waste of heat energy, in this embodiment, the steam-molten salt heat exchanger 710 is provided with a non-condensable gas outlet and is connected to a first non-condensable gas pipeline 711. The non-condensable gas outlet of the steam-molten salt heat exchanger 710 is connected to the steam-water heat exchanger 800 through the first non-condensable gas pipeline 711 to transport the uncondensed steam to the steam-water heat exchanger 800 for reuse, and then to the heating network or boiler water supply system. Such a design significantly improves the steam utilization efficiency and realizes the deep coupling between the steam, molten salt and water cycles, thereby reducing the overall energy loss of the system.

[0028] Furthermore, the high-pressure cylinder 210 of the steam turbine is connected to the reheater inlet of the boiler 100 through the first exhaust steam pipe 211, the intermediate-pressure cylinder 220 of the steam turbine is connected to the steam inlet of the low-pressure cylinder 230 of the steam turbine through the second exhaust steam pipe 221, and the low-pressure cylinder 230 of the steam turbine is connected to the condenser 600 through the third exhaust steam pipe 231, and the outlet of the condenser 600 is connected to the low-pressure heater 500 via the condensate pump 610. The turbine high-pressure cylinder 210 is connected to a first steam extraction pipeline 212, the turbine intermediate-pressure cylinder 220 is connected to a second steam extraction pipeline 222, and the turbine low-pressure cylinder 230 is connected to a third steam extraction pipeline 232. The turbine high-pressure cylinder 210 and the turbine intermediate-pressure cylinder 220 are connected to the steam extraction inlet of the high-pressure heater 300 through the first steam extraction pipeline 212 and the second steam extraction pipeline 222 respectively, and the turbine low-pressure cylinder 230 is connected to the steam extraction inlet of the low-pressure heater 500 through the third steam extraction pipeline 232. This multi-stage steam extraction design is convenient for dynamically adjusting the steam extraction amount according to the power generation load and heating demand, so that the heating and power generation are synergistically optimized, thereby ensuring the overall efficiency of the system operation. The first outlet water supply pipe 320 of the high-pressure heater 300 is connected to the superheater inlet of the boiler 100, and the turbine intermediate-pressure cylinder 220 is also connected to a fourth exhaust steam pipe 223. The turbine intermediate-pressure cylinder 220 is connected to the steam extraction inlet of the deaerator 400 through the fourth exhaust steam pipe 223. The high-pressure heater 300 is connected to the steam extraction inlet of the deaerator 400 through the first drain pipe 310, and the low-pressure heater 500 is connected to the steam extraction inlet of the deaerator 400 through the second outlet water supply pipe 520.

[0029] The heat extraction and heating system for deep peak regulation of thermal power units provided in the embodiment of the present application, through the reheat steam pipeline 102, the reheat steam of the boiler 100 is directly transported to the steam inlet of the steam-molten salt heat exchanger 710 through the reheat steam extraction pipeline 103, which can realize the direct transfer of steam heat to the molten salt. This design eliminates the complex path in which the steam heat needs to be transferred through multiple stages of equipment in the traditional system, and can reduce the loss of heat during the transfer process. At the same time, the reheat steam pipeline 102 connects the boiler 100 and the steam turbine intermediate pressure cylinder 220, which is used to transport reheat steam to the steam turbine intermediate pressure cylinder 220, and the reheat steam extraction pipeline 103 is connected to the reheat steam pipeline 102, which can directly introduce part of the reheat steam into the steam-molten salt heat exchanger 710, so as to realize the efficient transfer of the reheat steam heat energy. Through this connection method, the steam-molten salt heat exchanger 710 can receive high-temperature reheat steam from the boiler, providing a stable source of heat energy for molten salt heat exchange.

[0030] In the above-mentioned embodiment of the present application, the steam-molten salt heat exchanger 710 is connected to the steam-water heat exchanger 800 by setting a non-condensable gas outlet and a first non-condensable gas pipeline 711, and the incompletely condensed steam can enter the steam-water heat exchanger 800 for secondary heat transfer, and the waste heat is further recovered to the heating network. This design method can solve the problem of non-condensable steam being directly discharged in the prior art, and the heat transfer path is extended by reasonable layout. Moreover, this design not only utilizes the sensible heat of steam, but also recovers the latent heat to the maximum extent, realizing the coordinated operation of steam and molten salt. Through the multiple use of non-condensable steam in this application, the ability of the overall heat recovery of the system can be significantly improved, while reducing heat loss, providing a more stable heat source support for the heating network.

[0031] In addition, the embodiment of the present application establishes an orderly connection between the boiler 100, the turbine module 200 and the steam-molten salt heat exchanger 710 through the main steam pipe 101, the reheat steam pipe 102 and the reheat steam extraction pipe 103. After the steam is released in stages in the turbine high-pressure cylinder 210 and the turbine intermediate-pressure cylinder 220, a portion of the reheat steam enters the molten salt heat exchange system 700 through the reheat steam extraction pipe 103, wherein the steam-molten salt heat exchanger 710 completes the transfer of heat to the molten salt. This design enables the molten salt heat exchange system 700 to dynamically access the entire heating process, reduce the intermediate steps required for heat transfer from steam to the heating system, shorten the heat transfer time, and the present application can achieve efficient coordination with the heating network through the reasonable layout of the molten salt heat exchange system 700, thereby improving the problem of slow heating response caused by inflexible heat distribution in the prior art.

[0032] In some embodiments, the molten salt heat exchange system 700 includes a steam-molten salt heat exchanger 710, a molten salt hot tank 720, a molten salt cold tank 730, and a molten salt-feed water heat exchanger 740. The molten salt output end of the molten salt-feed water heat exchanger 740 is connected to the input end of the molten salt cold tank 730 through a pipeline, the output end of the molten salt cold tank 730 is connected to the molten salt input end of the steam-molten salt heat exchanger 710 through a pipeline, the molten salt output end of the steam-molten salt heat exchanger 710 is connected to the input end of the molten salt hot tank 720 through a pipeline, and the output end of the molten salt hot tank 720 is connected to the molten salt input end of the steam-molten salt heat exchanger 710 through a pipeline. The outlet end is connected to the molten salt input end of the molten salt-feed water heat exchanger 740 through a pipeline, forming a closed-loop circulation path of the molten salt. During use, the reheated steam can enter the steam-molten salt heat exchanger 710 through the reheated steam extraction pipe 103. After transferring the heat energy to the molten salt, the molten salt is transported to the molten salt hot tank 720 to store heat, and then releases heat to the feed water through the molten salt-feed water heat exchanger 740 according to system requirements. Such a closed-loop design can ensure the high efficiency of molten salt heat storage and transfer, laying the foundation for the flexible response of the heating system.

[0033] In the prior art, the connection relationship between the molten salt heat exchange device and the boiler and the steam-water heat exchanger is relatively fixed, and it is not possible to flexibly respond to the needs of multi-stage thermal energy utilization. This embodiment designs a molten salt heat exchange circuit composed of a steam-molten salt heat exchanger 710, a molten salt hot tank 720, a molten salt cold tank 730 and a molten salt-feed water heat exchanger 740, and can realize the dynamic coupling of the molten salt heat exchange system 700 with the boiler water supply and heating network during operation. In addition, the steam-molten salt heat exchanger 710 is connected to the reheat steam extraction pipeline 103, so that the molten salt can fully absorb the heat in the steam, store the heat energy in the molten salt hot tank 720, and then flexibly release the heat according to the heating demand, which can not only reduce the direct consumption of steam, but also efficiently utilize multi-stage thermal energy.

[0034] Further, the outlet water supply pipe 410 of the deaerator 400 is connected to the high-pressure heater 300 and the molten salt-feed water heat exchanger 740 respectively through the feed water pump 420, and the heating water outlet of the molten salt-feed water heat exchanger 740 is connected to the heating water supply pipe 741, and the heating water outlet of the molten salt-feed water heat exchanger 740 is connected to the first outlet water supply pipe 320 through the heating water supply pipe 741, so as to transport the heated feed water in the molten salt-feed water heat exchanger 740 to the boiler 100, which can efficiently transfer the heat released by the molten salt to the boiler water supply. Different from the traditional single-path heating method, this design can directly use the heat stored in the molten salt heat exchange system 700 during the water supply process of the boiler 100, reduce the intermediate transfer link, and reduce heat loss. In addition, the heating water supply pipe 741 can ensure the stability of the water supply temperature and improve the operating efficiency of the boiler 100.

[0035] The core function of the molten salt-feed water heat exchanger 740 is to directly heat the feed water by releasing the heat energy of the molten salt to meet the heating demand. In this embodiment, the heating water supply pipe 741 is connected to the first outlet water supply pipe 320, thereby realizing the connection between the heating water supply pipe 741 and the boiler 100. In actual use, a flexible heat distribution method can be provided. Especially when the boiler load is high or the heating demand increases suddenly, the molten salt heat exchange system 700 can quickly transfer heat to the boiler 100 through the heating water supply pipe 741 to indirectly support the heating network, significantly improving the heating response speed and efficiency of the system.

[0036] In some embodiments, a pressure reducing valve 104 is provided on the reheat steam extraction pipe 103 .

[0037] In the above embodiment, by setting a pressure reducing valve 104 on the reheat steam extraction pipe 103, the pressure of the reheat steam transported from the boiler 100 to the steam-molten salt heat exchanger 710 through the reheat steam extraction pipe 103 can be adjusted. The regulating effect of the steam pressure can reduce the steam pressure to a suitable level according to the working requirements of the steam-molten salt heat exchanger 710, thereby optimizing the transfer efficiency of the steam heat to the molten salt. Through such a design, the equipment damage to the steam-molten salt heat exchanger 710 caused by excessive steam pressure is avoided, and the load of the molten salt heat exchange system 700 during operation is also reduced, thereby making the operation of the lifting system more stable. In addition, the setting of the pressure reducing valve 104 makes the pressure of the reheat steam more controllable, further enhances the adjustment ability of the system, enables it to adapt to the heat transfer requirements under various working conditions, and provides a guarantee for the safety and flexibility of the system operation.

[0038] In some embodiments, the low-pressure heater 500 is connected to the condenser 600 through a second drain pipe 510, the steam-water heat exchanger 800 is provided with a non-condensable gas outlet and is connected to a second non-condensable gas pipe 810, and the non-condensable gas outlet of the steam-water heat exchanger 800 is connected to the condenser 600 through the second non-condensable gas pipe 810.

[0039] In the above embodiment, by connecting the second drain pipe 510 between the low-pressure heater 500 and the condenser 600, and connecting the non-condensable gas outlet of the steam-water heat exchanger 800 to the condenser 600 through the second non-condensable gas pipe 810, the centralized discharge and treatment of drain and non-condensable gas can be achieved. The drain generated by the low-pressure heater 500 directly enters the condenser 600 through the second drain pipe 510, avoiding the system pressure fluctuation caused by the accumulation of drain, and improving the drain recovery efficiency. The uncondensed gas in the steam-water heat exchanger 800 enters the condenser 600 through the second non-condensable gas pipe 810, and is further cooled and treated after being fully contacted with the cooling water of the condenser 600. This design reduces the heat waste and energy efficiency loss caused by the direct discharge of non-condensable gas into the environment. Through the above layout, the discharge paths of the low-pressure heater 500 and the steam-water heat exchanger 800 are optimized, which not only improves the stability of system operation, but also simplifies the condensation and drain recovery process, and further improves the resource utilization efficiency of the thermal power unit heating system.

[0040] In some embodiments, the steam-water heat exchanger 800 is connected to the deaerator 400 through a drain return pipe 820. The drain return pipe 820 is provided to transport the drain in the steam-water heat exchanger 800 to the deaerator 400, thereby forming a closed-loop system of water circulation. This design not only reduces the waste of water resources in the heating process, but also ensures the effective operation of the system in terms of thermal energy utilization and water resource circulation.

[0041] In some embodiments, a pressure water pump 840 is provided on the drain return pipe 820, which can quickly transport the drain generated in the steam-water heat exchanger 800 back to the deaerator 400, complete the reuse of the circulating water, and avoid the retention of drain in the pipe or the problem of reduced flow rate due to gravity, thereby helping to improve the efficiency of drain recovery. The steam-water heat exchanger 800 is also connected to a normal pressure water pump 830, the inlet of the normal pressure water pump 830 is connected to the normal pressure water source, and the outlet of the normal pressure water pump 830 is connected to the water input end of the steam-water heat exchanger 800 through a pipeline, which is used to transport normal pressure water to the steam-water heat exchanger 800, thereby ensuring that the steam-water heat exchanger 800 can obtain sufficient water source support under various working conditions. The design adopted in this embodiment makes the drain return and water source replenishment more flexible and fast through the cooperation of two pumps, which can improve the operating stability of the steam-water heat exchanger 800 and reduce the fluctuation of the heating system that may be caused by poor water flow.

[0042] In some embodiments, Figure 2 As shown, the steam-water heat exchanger 800 is connected to the heating network via a heating pipe 801 .

[0043] This embodiment connects the steam-water heat exchanger 800 to the heating pipe 801 and further connects it to the heating network, so that the waste heat of steam can be directly transferred to the heating network. This connection method can quickly transfer the heat recovered from the steam-water heat exchanger 800 to the heating network, effectively reducing the intermediate links in the heat transfer path, thereby reducing heat loss. In addition, by connecting the heating network through the heating pipe 801, the heat recovered by the steam-water heat exchanger 800 can be flexibly used to meet the regional heating needs and improve the efficiency of heat utilization. This layout method enables the heating system to dynamically adjust the heat distribution in the heating pipe according to the actual heat load demand, providing a more stable and continuous heat source for the heating network, while reducing the pressure on other heating modules, thereby optimizing the overall operating performance of the system. Through such a design, the steam-water heat exchanger 800 in this embodiment not only plays a role in recovering heat, but also provides key support in the dynamic heat balance of the heating network.

[0044] In some embodiments, the steam-molten salt heat exchanger 710 adopts a spiral coil heat exchange structure to improve heat transfer efficiency.

[0045] The spiral coil heat exchange structure used in the steam-molten salt heat exchanger 710 can increase the effective heat exchange area of ​​the heat exchanger, so that the steam and molten salt can complete the heat transfer in a shorter path, thereby making the heat exchange between the steam and the molten salt more complete, avoiding the local flow dead angle that may appear in the traditional straight tube heat exchanger, thereby improving the uniformity of heat transfer. At the same time, the compact design of the spiral coil structure can also reduce the overall volume of the heat exchanger, help reduce the equipment installation space requirements, and optimize the overall layout of the molten salt heat exchange system 700.

[0046] In some embodiments, Figure 3 As shown, the heating water supply pipeline 741 is connected to a heating bypass pipeline 742 , the heating bypass pipeline 742 is connected to the heating supply pipeline 801 , and a regulating valve 743 is provided on the heating bypass pipeline 742 .

[0047] In the prior art, the heat energy released by the molten salt heat exchange device is difficult to directly enter the heating network, and the response speed is slow, thereby limiting the flexibility and efficiency of the system. In this embodiment, by connecting the heating bypass pipe 742 to the heating water supply pipe 741 and directly connecting it to the heating pipe 801, during the peak heating period, the heated feed water can be preferentially delivered directly to the heating network through the regulating valve 743 without the need for secondary heating by the boiler. This method can greatly improve the thermal energy distribution efficiency of the system during the peak heating period, can achieve the goal of quickly responding to heating needs, and at the same time avoid the response lag problem caused by the lengthy heat energy transfer path in the traditional system.

[0048] The present application also provides an operating method of a heat extraction and heating system for deep peak regulation of a thermal power unit, which is applied to the heat extraction and heating system for deep peak regulation of a thermal power unit provided in the above-mentioned embodiment of the present application. The operating method includes: a. Steam cycle process: a1. The high-temperature and high-pressure steam generated by the boiler 100 is transported to the high-pressure cylinder 210 of the steam turbine through the main steam pipe 101; a2. The steam discharged from the high-pressure cylinder 210 of the steam turbine enters the reheater of the boiler 100 through the first exhaust pipe 211 for reheating to form reheated steam; a3. The reheated steam is transported to the steam turbine intermediate pressure cylinder 220 through the reheated steam pipe 102, and the steam exhausted from the steam turbine intermediate pressure cylinder 220 is transported to the steam turbine low pressure cylinder 230 through the second exhaust steam pipe 221; a4. The steam exhausted from the low-pressure cylinder 230 of the steam turbine is transported to the condenser 600 through the third exhaust pipe 231 for cooling and recovery; b. Molten salt heat exchange cycle process: b1. The reheated steam is introduced into the steam-molten salt heat exchanger 710 through the reheated steam extraction pipeline 103 to transfer heat energy to the molten salt; b2. The uncondensed steam in the steam-molten salt heat exchanger 710 is transported to the steam-water heat exchanger 800 through the non-condensable gas outlet and the first non-condensable gas pipeline 711 to further utilize the waste heat; b3. The heated molten salt is transported to the molten salt-feed water heat exchanger 740 through the molten salt hot tank 720 to transfer the heat to the feed water; b4. The cooled molten salt returns to the steam-molten salt heat exchanger 710 through the molten salt cold tank 730 to complete the molten salt closed-loop circulation; c. Water supply cycle process: c1. The deaerator 400 deoxygenates the feed water, and the treated feed water is transported to the high-pressure heater 300 and the molten salt-feed water heat exchanger 740 through the feed water pump 420; c2. The feed water heated in the molten salt-feed water heat exchanger 740 is transported to the superheater inlet of the boiler 100 through the heating water supply pipe 741 for further heating; c3. During the peak heating period, part of the heated feed water is directly transported to the heating pipeline 801 through the heating bypass pipeline 742 to meet the heating demand; c4. The drain generated in the steam-water heat exchanger 800 is transported to the deaerator 400 through the drain return pipe 820 to complete the closed-loop circulation.

[0049] In the above embodiment, the steam cycle process adopted can realize the graded release and transfer of heat energy. When in use, high-temperature and high-pressure steam is transported from the boiler 100 to the high-pressure cylinder 210 of the steam turbine via the main steam pipe 101, and then passes through the medium-pressure cylinder 220 of the steam turbine and the low-pressure cylinder 230 of the steam turbine in sequence. This method enables the sensible heat of steam to be fully utilized at different pressures, which not only reduces the situation where the steam heat energy is quickly exhausted in one link, but also provides a suitable steam heat source for the subsequent steam-molten salt heat exchanger 710 and steam-water heat exchanger 800 of the system. At the same time, by transporting the steam discharged from the low-pressure cylinder to the condenser 600 for cooling and recovery, a closed-loop path of the steam cycle is formed. This design effectively reduces the waste of heat energy, makes the heat utilization of steam more uniform, and provides stable heat energy support for the overall operation of the system.

[0050] The molten salt heat exchange cycle process transfers the heat energy of the steam to the molten salt by introducing the reheated steam from the reheated steam extraction pipe 103 into the steam-molten salt heat exchanger 710, completing a sensible heat transfer. The steam that is not fully condensed enters the steam-water heat exchanger 800 through the non-condensable gas pipe 711 to achieve secondary waste heat utilization. In this process, the molten salt acts as an intermediate heat storage medium, and completes the heat storage and release functions through the circulation of the molten salt hot tank 720 and the cold tank 730, thereby improving the system's ability to regulate under thermal load fluctuations. In particular, when the heating demand changes, the molten salt heat exchange system 700 can respond quickly, transfer the stored heat to the feed water through the molten salt-feed water heat exchanger 740, and realize multi-stage utilization of heat. This design reduces the direct loss of heat energy and provides a more stable source of heat for the heating system.

[0051] During the water supply circulation process, the feed water treated by the deaerator 400 is transported to the high-pressure heater 300 and the molten salt-feed water heat exchanger 740 through the feed water pump 420 to complete the heating of the water supply. During the peak heating period, part of the feed water heated by the molten salt-feed water heat exchanger 740 directly enters the heating pipe 801 through the heating bypass pipe 742, realizing the rapid supply of heat and avoiding the time delay of boiler reheating. At the same time, the drain generated in the steam-water heat exchanger 800 returns to the deaerator 400 through the drain return pipe 820, forming a closed-loop recovery of water resources. This design not only improves the efficiency of water supply utilization, but also enables the heating network to dynamically adjust the heat distribution path, thereby maintaining the stability and flexibility of the heating network under different heating demands.

[0052] The heating system provided in the embodiment of the present application has a certain load regulation capability and can adapt to deep peak load regulation conditions, as described below: This system can dynamically adjust the heat distribution between heating and power generation. This application realizes the step-by-step release of steam thermal energy through the multi-stage path design of steam between the boiler 100, the turbine module 200 and the molten salt heat exchange system 700. The high-temperature and high-pressure steam generated by the boiler enters the turbine high-pressure cylinder 210, the turbine medium-pressure cylinder 220 and the turbine low-pressure cylinder 230 in sequence, gradually releasing heat energy to drive the turbine to generate electricity. This hierarchical utilization design avoids the rapid exhaustion of steam thermal energy in a single link. At the same time, part of the steam is introduced into the steam-molten salt heat exchanger 710 through the reheat steam extraction pipeline 103 to provide a heat source for the molten salt heat exchange system 700. Under low-load conditions, by reasonably adjusting the steam extraction volume, the steam demand for the medium and low-pressure cylinders of the turbine can be reduced, and flexible switching between heating and power generation loads can be achieved.

[0053] The heat storage and release capabilities of the molten salt heat exchange system of the embodiment of the present application can enhance the adaptability of the system. The molten salt heat exchange system 700 provides the system with a dynamic heat regulation function through the synergistic effect of the steam-molten salt heat exchanger 710, the molten salt hot tank 720 and the molten salt-feed water heat exchanger 740. When operating at low load, the system can store excess heat energy through the molten salt hot tank to provide reserve support for subsequent peak loads; and when the demand for heating increases suddenly, the molten salt-feed water heat exchanger 740 heats the feed water by quickly releasing the stored heat, and part of the heated feed water can directly enter the heating pipe 801 through the heating bypass pipe 742 to meet the needs of the heating network. This design reduces the intermediate links in heat transfer, shortens the response time, and improves the regulation capability of the heating load.

[0054] At the same time, the closed-loop design of the water circulation system can optimize resource utilization and load regulation. In terms of water circulation, the system realizes the closed-loop circulation of condensed water and drain during the heating process through the close connection of the deaerator 400, the steam-water heat exchanger 800 and the drain return pipe 820. The uncondensed waste heat steam in the steam-water heat exchanger 800 is further utilized, and the drain generated returns to the deaerator 400 through the drain return pipe for subsequent water supply heating. At the same time, during the water supply circulation process, the system can dynamically adjust the water supply path according to different load conditions. For example, during the peak of heating, heated water is directly delivered to the heating pipe through the heating bypass pipe. This optimized design of the water cycle reduces the waste of heat energy and water resources, while ensuring the stability of the system when operating at low loads, providing good support for deep peak-shaving conditions.

[0055] From the above, it can be seen that the heating system of the embodiment of the present application can dynamically adjust the heat distribution between heating and power generation through the organic combination of steam cycle, molten salt heat exchange cycle and water cycle to adapt to the load requirements under different working conditions. The synergistic effect of cascade utilization, dynamic storage and resource recovery enables the system to have a certain load regulation capability, which can meet the high flexibility and stability requirements during deep peak load operation.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, ordinary technicians in the field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A heat extraction and heating system for deep peak regulation of thermal power units, characterized in that: It includes a boiler (100), a steam turbine module (200), a high-pressure heater (300), a deaerator (400), a low-pressure heater (500), a condenser (600), a molten salt heat exchange system (700) and a steam-water heat exchanger (800); The steam turbine module (200) comprises a steam turbine high-pressure cylinder (210), a steam turbine intermediate-pressure cylinder (220) and a steam turbine low-pressure cylinder (230); the boiler (100) is used to generate high-temperature and high-pressure steam; the boiler (100) is connected to the steam turbine high-pressure cylinder (210) via a main steam pipeline (101); the boiler (100) is also connected to the steam turbine intermediate-pressure cylinder (220) via a reheat steam pipeline (102); a reheat steam extraction pipeline (103) is provided on the reheat steam pipeline (102); the output end of the reheat steam extraction pipeline (103) is connected to the steam inlet of a steam-molten salt heat exchanger (710) to transfer the heat energy of the steam to the molten salt; the steam- The molten salt heat exchanger (710) is provided with a non-condensable gas outlet and is connected to a first non-condensable gas pipeline (711); the non-condensable gas outlet of the steam-molten salt heat exchanger (710) is connected to the steam-water heat exchanger (800) through the first non-condensable gas pipeline (711) so as to transport uncondensed steam to the steam-water heat exchanger (800) for reuse; the high-pressure cylinder (210) of the steam turbine is connected to the reheater inlet of the boiler (100) through the first exhaust steam pipeline (211); the intermediate-pressure cylinder (220) of the steam turbine is connected to the steam inlet of the low-pressure cylinder (230) of the steam turbine through the second exhaust steam pipeline (221); the low-pressure cylinder (230) of the steam turbine is connected to the steam inlet of the low-pressure cylinder (230) of the steam turbine through the third exhaust steam pipeline (211); (231) is connected to the condenser (600), the outlet of the condenser (600) is connected to the low-pressure heater (500) via a condensate pump (610), the high-pressure cylinder (210) of the steam turbine is connected to a first steam extraction pipeline (212), the intermediate-pressure cylinder (220) of the steam turbine is connected to a second steam extraction pipeline (222), and the low-pressure cylinder (230) of the steam turbine is connected to a third steam extraction pipeline (232). The high-pressure cylinder (210) of the steam turbine and the intermediate-pressure cylinder (220) of the steam turbine are connected to the steam extraction inlet of the high-pressure heater (300) via the first steam extraction pipeline (212) and the second steam extraction pipeline (222), respectively. The low-pressure cylinder (230) of the steam turbine is connected to the steam extraction inlet of the high-pressure heater (300) via the third steam extraction pipeline. The steam turbine intermediate pressure cylinder (220) is also connected to a fourth exhaust steam pipe (223); the steam turbine intermediate pressure cylinder (220) is connected to the steam extraction inlet of the deaerator (400) through the fourth exhaust steam pipe (223); the high pressure heater (300) is connected to the steam extraction inlet of the deaerator (400) through the first drain pipe (310); and the low pressure heater (500) is connected to the steam extraction inlet of the deaerator (400) through the second outlet feed water pipe (520).

2. The heat extraction and heating system for deep peak load regulation of thermal power units according to claim 1, characterized in that: The molten salt heat exchange system (700) comprises a steam-molten salt heat exchanger (710), a molten salt hot tank (720), a molten salt cold tank (730) and a molten salt-feed water heat exchanger (740), wherein the molten salt output end of the molten salt-feed water heat exchanger (740) is connected to the input end of the molten salt cold tank (730) via a pipeline, the output end of the molten salt cold tank (730) is connected to the molten salt input end of the steam-molten salt heat exchanger (710) via a pipeline, the molten salt output end of the steam-molten salt heat exchanger (710) is connected to the input end of the molten salt hot tank (720) via a pipeline, and the output end of the molten salt hot tank (720) is connected to the The molten salt input end of the molten salt-feed water heat exchanger (740) is connected; the outlet water feed water pipeline (410) of the deaerator (400) is respectively connected to the high-pressure heater (300) and the molten salt-feed water heat exchanger (740) via a feed water pump (420); the heating water outlet of the molten salt-feed water heat exchanger (740) is connected to a heating water supply pipeline (741); the heating water outlet of the molten salt-feed water heat exchanger (740) is connected to the first outlet feed water pipeline (320) through the heating water supply pipeline (741), so as to transport the feed water heated in the molten salt-feed water heat exchanger (740) to the boiler (100).

3. The heat extraction and heating system for deep peak load regulation of thermal power units according to claim 2, characterized in that: The reheat steam extraction pipeline (103) is provided with a pressure reducing valve (104).

4. The heat extraction and heating system for deep peak load regulation of thermal power units according to claim 2 or 3, characterized in that: The low-pressure heater (500) is connected to the condenser (600) via a second drain pipe (510); the steam-water heat exchanger (800) is provided with a non-condensable gas outlet and is connected to a second non-condensable gas pipe (810); the non-condensable gas outlet of the steam-water heat exchanger (800) is connected to the condenser (600) via the second non-condensable gas pipe (810).

5. The heat extraction and heating system for deep peak load regulation of thermal power units according to claim 4, characterized in that: The steam-water heat exchanger (800) is connected to the deaerator (400) via a drain return pipe (820).

6. The heat extraction and heating system for deep peak load regulation of thermal power units according to claim 5, characterized in that: A pressure water pump (840) is provided on the drain return pipe (820), and the steam-water heat exchanger (800) is also connected to a normal-pressure water pump (830), the inlet of the normal-pressure water pump (830) is connected to a normal-pressure water source, and the outlet of the normal-pressure water pump (830) is connected to the water input end of the steam-water heat exchanger (800) through a pipe, so as to transport normal-pressure water to the steam-water heat exchanger (800).

7. The heat extraction and heating system for deep peak load regulation of thermal power units according to claim 4, characterized in that: The steam-water heat exchanger (800) is connected to the heating network via a heating pipeline (801).

8. The heat extraction and heating system for deep peak load regulation of thermal power units according to claim 1, characterized in that: The steam-molten salt heat exchanger (710) adopts a spiral coil heat exchange structure to improve heat transfer efficiency.

9. The heat extraction and heating system for deep peak load regulation of thermal power units according to claim 7, characterized in that: The heating water supply pipeline (741) is connected to a heating bypass pipeline (742), the heating bypass pipeline (742) is connected to the heating supply pipeline (801), and a regulating valve (743) is provided on the heating bypass pipeline (742).

10. An operating method for a heat extraction and heating system for deep peak regulation of a thermal power unit, characterized in that: The heat extraction and heating system for deep peak regulation of a thermal power unit according to any one of claims 1 to 9, wherein the operation method comprises: a. Steam cycle process: a1. High-temperature and high-pressure steam generated by the boiler (100) is transported to the high-pressure cylinder (210) of the steam turbine through the main steam pipe (101); a2. Steam discharged from the high-pressure cylinder (210) of the steam turbine enters the reheater of the boiler (100) through the first exhaust pipe (211) to be reheated to form reheated steam; a3. The reheated steam is transported to the steam turbine intermediate pressure cylinder (220) through the reheated steam pipe (102), and the steam exhausted from the steam turbine intermediate pressure cylinder (220) is transported to the steam turbine low pressure cylinder (230) through the second steam exhaust pipe (221); a4. The steam exhausted from the low-pressure cylinder (230) of the steam turbine is transported to the condenser (600) through the third exhaust pipe (231) for cooling and recovery; b. Molten salt heat exchange cycle process: b1. The reheated steam is introduced into the steam-molten salt heat exchanger (710) through the reheated steam extraction pipeline (103), and the heat energy is transferred to the molten salt; b2. The uncondensed steam in the steam-molten salt heat exchanger (710) is transported to the steam-water heat exchanger (800) through the non-condensable gas outlet and the first non-condensable gas pipeline (711) to further utilize the waste heat; b3. The heated molten salt is transported to the molten salt-feed water heat exchanger (740) through the molten salt hot tank (720) to transfer heat to the feed water; b4. The cooled molten salt returns to the steam-molten salt heat exchanger (710) through the molten salt cold tank (730), completing the molten salt closed-loop circulation; c. Water supply cycle process: c1. The deaerator (400) performs deoxygenation treatment on the feed water, and the treated feed water is transported to the high-pressure heater (300) and the molten salt-feed water heat exchanger (740) through the feed water pump (420); c2. The feed water heated in the molten salt-feed water heat exchanger (740) is transported to the superheater inlet of the boiler (100) through the heating water supply pipe (741) for further heating; c3. During the peak heating period, part of the heated feed water is directly transported to the heating pipeline (801) through the heating bypass pipeline (742) to meet the heating demand; c4. The drain generated in the steam-water heat exchanger (800) is transported to the deaerator (400) through the drain return pipe (820), completing a closed-loop circulation.

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