Subcritical / supercritical steam generator and high temperature gas cooled reactor

Abstract

The application provides a supercritical steam generator matched with a high-temperature gas cooled reactor, and the high-temperature gas cooled reactor, the steam generator comprises a shell, a low-temperature heat exchange device and a high-temperature heat exchange device, the shell is internally provided with a heat exchange cavity and a reflux cavity in communication, the shell is provided with a high-temperature heat medium inlet and a low-temperature heat medium outlet, the low-temperature heat exchange device and the high-temperature heat exchange device are arranged in an axial direction of the shell, the high-temperature heat exchange device is adjacent to the high-temperature heat medium inlet, and an output end of the low-temperature heat exchange device is connected with an input end of the high-temperature heat exchange device. The steam generator of the embodiment of the application can be manufactured by using high-temperature materials which have been widely applied in the field of thermal power, so that the manufacturing cost of the steam generator is reduced, and the steam generator can better adapt to market development.

Description

Technical Field

[0001] This article relates to nuclear reactor technology, particularly a subcritical / supercritical steam generator and a high-temperature gas-cooled reactor. Background Technology

[0002] High-temperature gas-cooled reactors (HTGRs) are advanced nuclear reactors with broad application prospects, characterized by safety, system simplification, high power generation efficiency, continuous fuel loading and unloading, and modular construction. The steam generator in an HTGR is a key component for achieving heat exchange between the primary and secondary sides, significantly impacting both reactor safety and economics. With the continuous development of HTGR technology, its inherent safety has been accepted and recognized by various sectors of society. Under this premise, lowering the nuclear safety level of the steam generator, or adjusting the steam generator to a non-safety level with additional special treatment, becomes a possibility.

[0003] In related technologies, steam generators are an important component of high-temperature gas-cooled reactors and have a high nuclear safety level. Due to the extremely high temperatures of the high-temperature helium and steam inside the steam generator, the material requirements for the heat exchange tubes are strict, resulting in high design and manufacturing standards and costs for steam generators, making them difficult to adapt to market development. Therefore, how to reasonably optimize the equipment and reduce manufacturing costs to adapt it to market development while ensuring the overall technical safety is an important problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] This invention aims to improve the operational flexibility of steam generators while optimizing structural design to reduce manufacturing costs, all while ensuring generator safety. To this end, embodiments of this invention propose a subcritical / supercritical steam generator and a high-temperature gas-cooled reactor. The steam generator has low manufacturing costs, which is conducive to market development.

[0005] This invention provides a subcritical / supercritical steam generator, comprising a shell, a low-temperature heat exchanger, and a high-temperature heat exchanger. The shell has a communicating heat exchange chamber and a reflux chamber. A high-temperature heat transfer medium inlet and a low-temperature heat transfer medium outlet are provided on the shell. The high-temperature heat transfer medium inlet, the heat exchange chamber, the reflux chamber, and the low-temperature heat transfer medium outlet are sequentially connected. At least a portion of the low-temperature heat exchanger and at least a portion of the high-temperature heat exchanger are disposed within the heat exchange chamber. The low-temperature heat exchanger and the high-temperature heat exchanger are arranged axially spaced along the shell, with the high-temperature heat exchanger adjacent to the high-temperature heat transfer medium inlet. The output end of the low-temperature heat exchanger is connected to the input end of the high-temperature heat exchanger. The heat transfer medium flowing into the heat exchange chamber through the high-temperature heat transfer medium inlet sequentially exchanges heat with the high-temperature heat exchanger and the low-temperature heat exchanger, and flows out through the reflux chamber from the low-temperature heat transfer medium outlet.

[0006] In some embodiments, the design parameters of the steam generator satisfy: Heat exchange capacity less than 320MW; The temperature of the heat transfer medium at the inlet of the high-temperature heat transfer medium is less than 700°C. The pressure of the heat transfer medium inside the shell is less than 8 MPa; The temperature of the heat exchange medium at the input end of the low-temperature heat exchange device is less than 250°C. The temperature of the heat exchange medium in the low-temperature heat exchanger and the high-temperature heat exchanger is less than 600°C.

[0007] In some embodiments, the low-temperature heat exchanger is located below the high-temperature heat exchanger, and the flow direction of the heat exchange medium on the inner tube side of the low-temperature heat exchanger is opposite to that of the heat transfer medium on the inner shell side of the heat exchange cavity, while the flow direction of the heat exchange medium on the inner tube side of the high-temperature heat exchanger is the same as or opposite to that of the heat transfer medium on the inner shell side of the heat exchange cavity.

[0008] In some embodiments, the cryogenic heat exchange device includes a cryogenic inlet connection assembly, a cryogenic heat exchange assembly, and a cryogenic outlet connection assembly. The cryogenic heat exchange assembly is disposed within the heat exchange chamber. The cryogenic inlet connection assembly passes through the housing and is connected to the input end of the cryogenic heat exchange assembly. The cryogenic outlet connection assembly passes through the housing and is connected to the output end of the cryogenic heat exchange assembly.

[0009] In some embodiments, the low-temperature inlet connection assembly includes a water supply manifold, a water supply pipe box, and a water supply connection pipe bundle connected in sequence. The water supply manifold is located outside the housing, the water supply pipe box passes through the housing, and the water supply connection pipe bundle is located inside the heat exchange cavity and connected to the low-temperature heat exchange assembly. The cryogenic outlet connection assembly includes a cryogenic steam outlet connection tube bundle, a cryogenic steam outlet tube box, and a cryogenic steam outlet header connected in sequence. The cryogenic steam outlet connection tube bundle is located inside the heat exchange cavity and connected to the high-temperature heat exchange assembly. The cryogenic steam outlet tube box passes through the housing, and the cryogenic steam outlet header is located outside the housing.

[0010] In some embodiments, the low-temperature inlet connection assembly further includes a detachable water supply side pipe section disposed between the water supply manifold and the water supply pipe box; The cryogenic outlet connection assembly also includes a detachable cryogenic steam outlet side pipe section disposed between the cryogenic steam outlet pipe box and the cryogenic steam outlet header.

[0011] In some embodiments, the low-temperature heat exchange assembly includes a low-temperature heat exchange tube, a low-temperature support plate, and a low-temperature positioning plate. The two ends of the low-temperature heat exchange tube are respectively connected to the low-temperature inlet connection assembly and the low-temperature outlet connection assembly. The low-temperature support plate and the low-temperature positioning plate are both fixedly disposed in the heat exchange cavity. The upper end of the low-temperature heat exchange tube is connected to the low-temperature support plate, and the low-temperature positioning plate is provided with a low-temperature guide hole, through which the lower end of the low-temperature heat exchange tube passes; or, the lower end of the low-temperature heat exchange tube is connected to the low-temperature support plate, the low-temperature positioning plate is provided with a low-temperature guide hole, and the upper end of the low-temperature heat exchange tube passes through the low-temperature guide hole.

[0012] In some embodiments, the cryogenic heat exchange assembly further includes a throttling element disposed at the inlet end of the cryogenic heat exchange tube, the throttling element being configured to provide throttling damping to stabilize the flow of the heat exchange medium.

[0013] In some embodiments, the high-temperature heat exchange device includes a high-temperature inlet connection assembly, a high-temperature heat exchange assembly, and a high-temperature outlet connection assembly. The high-temperature heat exchange assembly is disposed inside the heat exchange chamber. The high-temperature inlet connection assembly passes through the housing and is connected to the input end of the high-temperature heat exchange assembly. The high-temperature outlet connection assembly passes through the housing and is connected to the output end of the high-temperature heat exchange assembly. The low-temperature outlet connection assembly is connected to the high-temperature inlet connection assembly.

[0014] In some embodiments, the high-temperature inlet connection assembly includes a steam inlet header, a steam inlet pipe box, and a steam inlet connection pipe bundle connected in sequence. The steam inlet header is located outside the housing, the steam inlet pipe box passes through the housing, and the steam inlet connection pipe bundle is located inside the heat exchange cavity and connected to the high-temperature heat exchange assembly. The high-temperature outlet connection assembly includes a high-temperature steam outlet connection tube bundle, a high-temperature steam outlet tube box, and a high-temperature steam outlet header connected in sequence. The high-temperature steam outlet connection tube bundle is located inside the heat exchange cavity and connected to the high-temperature heat exchange assembly. The high-temperature steam outlet tube box passes through the housing, and the high-temperature steam outlet header is located outside the housing.

[0015] In some embodiments, the high-temperature inlet connection assembly further includes a detachable steam inlet side pipe section disposed between the steam inlet header and the steam inlet pipe box; The high-temperature outlet connection assembly also includes a detachable pipe section on the high-temperature steam outlet side disposed between the high-temperature steam outlet pipe box and the high-temperature steam outlet header.

[0016] In some embodiments, the high-temperature heat exchange assembly includes a high-temperature heat exchange tube, a high-temperature support plate, and a high-temperature positioning plate. The two ends of the high-temperature heat exchange tube are respectively connected to the high-temperature inlet connection assembly and the high-temperature outlet connection assembly. The high-temperature support plate and the high-temperature positioning plate are both fixedly disposed inside the heat exchange cavity. The upper end of the high-temperature heat exchange tube is connected to the high-temperature support plate, and the high-temperature positioning plate is provided with a high-temperature guide hole, through which the lower end of the high-temperature heat exchange tube passes; or, the lower end of the high-temperature heat exchange tube is connected to the high-temperature support plate, and the high-temperature positioning plate is provided with a high-temperature guide hole, through which the upper end of the high-temperature heat exchange tube passes.

[0017] In some embodiments, the subcritical / supercritical steam generator further includes a reheating device disposed within the heat exchange chamber. The reheating device is located on the side of the high-temperature heat exchange device away from the low-temperature heat exchange device, or between the high-temperature heat exchange device and the low-temperature heat exchange device. The reheating device is connected to the steam turbine to reheat the wet steam flowing out of the steam turbine.

[0018] In some embodiments, the reheating device includes a reheater, a reheat steam inlet pipe, and a reheat steam outlet pipe. One end of the reheat steam inlet pipe is connected to the reheat steam pipe of the steam turbine, and the other end passes through the casing and is connected to the input end of the reheater. One end of the reheat steam outlet pipe is connected to the output end of the reheater, and the other end passes through the casing and is connected to the reheat steam pipe of the steam turbine.

[0019] In some embodiments, the subcritical / supercritical steam generator further includes a heat insulation device disposed within the housing, the heat insulation device defining the heat exchange chamber, and the heat insulation device and the housing defining the reflux chamber.

[0020] In some embodiments, the heat insulation device includes a fixed cylinder and a heat insulation layer. The fixed cylinder is connected to the housing. The upper end of the fixed cylinder is closed and the lower end is open. The heat insulation layer is disposed on the inner wall surface and / or outer wall surface of the fixed cylinder.

[0021] In some embodiments, the subcritical / supercritical steam generator further includes a high-temperature heat transfer medium conveying device, which includes a hot gas duct and a duct shell. The duct shell is connected to the housing and forms a heat transfer medium channel. The hot gas duct passes through the heat transfer medium channel and communicates with the heat exchange chamber. The high-temperature heat transfer medium inlet is formed inside the hot gas duct, and the low-temperature heat transfer medium outlet is formed between the hot gas duct and the duct shell.

[0022] In some embodiments, the high-temperature heat transfer medium conveying device further includes a high-temperature medium homogenizing component, which is disposed in the heat exchange chamber. The high-temperature medium homogenizing component includes a connecting cylinder and an air outlet. One end of the connecting cylinder is connected to the hot gas duct, and the other end is connected to the air outlet. The air outlet is provided with a plurality of air outlet holes.

[0023] In some embodiments, the subcritical / supercritical steam generator further includes an air supply device comprising a fan assembly and a flow guide assembly. The fan assembly is connected to the top of the housing and provides a pressure head for the flow of the heat transfer medium. The flow guide assembly is disposed within the return chamber and is configured to guide the heat transfer medium in the return chamber to the fan assembly.

[0024] In some embodiments, the fan assembly includes a fan housing, a mounting bracket, and a fan body. The fan housing is connected to the top of the housing, and the inner cavity of the fan housing communicates with the return cavity. The mounting bracket is disposed at the connection between the fan housing and the housing, and the fan body is disposed on the mounting bracket.

[0025] In some embodiments, the flow guiding assembly includes a baffle plate, a heat transfer medium riser pipe, and a fan inlet header. The baffle plate is annular and disposed within the reflux cavity. The baffle plate has flow guiding holes. One end of the heat transfer medium riser pipe is connected to the baffle plate and corresponds to the flow guiding holes. The other end of the heat transfer medium riser pipe is connected to the input end of the fan inlet header. The output end of the fan inlet header is arranged opposite to the fan body. The heat transfer medium enters the fan body through the fan inlet header, flows out of the fan body, and then flows out sequentially through the reflux cavity and the low-temperature heat transfer medium outlet.

[0026] The present invention also provides a high-temperature gas-cooled reactor, including a pressure vessel, a reactor core, and a steam generator as described in any of the above embodiments. The reactor core is disposed inside the pressure vessel, and the steam generator is connected to the pressure vessel. The steam generator is positioned lower than the reactor core.

[0027] The subcritical / supercritical steam generator of this invention improves the reliability and flexibility of steam generator operation by incorporating high-temperature and low-temperature heat exchange devices internally, reduces the temperature deviation of the outlet steam, and can be designed and manufactured according to industrial or nuclear standards. Some of the manufacturing materials can be high-temperature materials that are already widely used in the thermal power field, reducing the manufacturing cost of the steam generator. It can better adapt to market development, which is conducive to industrial upgrading and technological innovation. In addition, the steam generator is compatible with existing high-temperature gas-cooled reactors and can achieve seamless integration without requiring changes or modifications to other equipment or systems.

[0028] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application can be realized and obtained by means of the embodiments described in the description and the accompanying drawings. Attached Figure Description

[0029] The accompanying drawings are used to provide an understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0030] Figure 1 This is a schematic diagram of a subcritical / supercritical steam generator according to an embodiment of this application; Figure 2 yes Figure 1 AA section view in the middle; Figure 3 yes Figure 1 BB section view in the middle; Figure 4 This is a schematic diagram of the low-temperature steam outlet header and steam inlet header of a subcritical / supercritical steam generator according to an embodiment of this application; Figure 5 yes Figure 4 CC section view in the middle; Figure 6 yes Figure 4 DD section view in the image.

[0031] Figure label: 1. Shell; 11. Heat exchange chamber; 12. Reflux chamber; 13. High-temperature heat transfer medium inlet; 14. Low-temperature heat transfer medium outlet; 2. Low-temperature heat exchanger; 21. Low-temperature inlet connection assembly; 211. Feed water header; 212. Feed water pipe box; 213. Feed water connecting pipe bundle; 214. Removable pipe section on the feed water side; 22. Low-temperature heat exchanger assembly; 221. Low-temperature heat exchange tube; 222. Low-temperature support plate; 223. Low-temperature positioning plate; 23. Low-temperature outlet connection assembly; 231. Low-temperature steam outlet connecting pipe bundle; 232. Low-temperature steam outlet pipe box; 233. Low-temperature steam outlet header; 234. Removable pipe section on the low-temperature steam outlet side; 3. High-temperature heat exchanger; 31. High-temperature inlet connection assembly; 311. Steam inlet header; 312. Steam inlet pipe box; 313. Steam inlet... 314. Steam inlet side detachable pipe section; 32. High temperature heat exchange assembly; 321. High temperature heat exchange tube; 322. High temperature support plate; 323. High temperature positioning plate; 33. High temperature outlet connection assembly; 331. High temperature steam outlet connection pipe bundle; 332. High temperature steam outlet pipe box; 333. High temperature steam outlet header; 334. High temperature steam outlet side detachable pipe section; 4. Insulation device; 41. Fixed cylinder; 42. Insulation layer; 5. High temperature heat transfer medium conveying device; 51. Hot gas duct; 52. Duct shell; 53. High temperature medium homogenization assembly; 531. Connecting cylinder; 532. Gas outlet; 61. Fan assembly; 611. Fan casing; 612. Fixing frame; 621. Baffle plate; 622. Heat transfer medium riser pipe; 623. Fan inlet header. Detailed Implementation

[0032] This application describes several embodiments, but these descriptions are exemplary and not limiting, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with, or may replace, any feature or element of any other embodiment.

[0033] This application includes and contemplates combinations of features and elements known to those skilled in the art. The embodiments, features, and elements disclosed in this application can also be combined with any conventional features or elements to form unique inventive solutions. Any feature or element of any embodiment can also be combined with features or elements from other inventive solutions to form another unique inventive solution. Therefore, it should be understood that any feature shown and / or discussed in this application can be implemented individually or in any suitable combination. Therefore, the embodiments are not limited except by the limitations imposed by the appended claims and their equivalents. Furthermore, various modifications and changes can be made within the scope of the appended claims.

[0034] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described herein, to the extent that it does not depend on such a specific order. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation of the claims. Moreover, the claims concerning the method and / or process should not be limited to the steps performed in the written order, and those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments of this application.

[0035] like Figures 1-3As shown, the subcritical / supercritical steam generator of this embodiment includes a shell 1, a cryogenic heat exchanger, and a high-temperature heat exchanger 3. The shell 1 has a heat exchange chamber 11 and a reflux chamber 12 connected inside. A high-temperature heat transfer medium inlet 13 and a cryogenic heat transfer medium outlet 14 are provided on the shell 1. The high-temperature heat transfer medium inlet 13, heat exchange chamber 11, reflux chamber 12, and cryogenic heat transfer medium outlet 14 are sequentially connected. This subcritical / supercritical steam generator is mainly used in high-temperature gas-cooled reactors. The heat transfer medium is high-temperature helium gas heated by the reactor core. The heat exchange media in the cryogenic heat exchanger 2 and the high-temperature heat exchanger 3 can be water and steam. The steam generator is arranged side-by-side with the reactor, and its position should be lower than the reactor core to prevent large-scale water ingress into the reactor core in the event of a large-scale feedwater leak from the steam generator's heat exchange tubes. At least a portion of the cryogenic heat exchanger 2 is disposed within the heat exchange chamber 11, and at least a portion of the high-temperature component is disposed within the heat exchange chamber 11. The cryogenic heat exchanger 2 and the high-temperature heat exchanger 3 exchange heat with the heat transfer medium within the heat exchange chamber 11. The cryogenic heat exchanger 2 and the high-temperature heat exchanger 3 are arranged axially spaced along the shell 1, with the high-temperature heat exchanger 3 adjacent to the high-temperature heat transfer medium inlet 13. The output end of the cryogenic heat exchanger 2 is connected to the input end of the high-temperature heat exchanger 3. The heat transfer medium provided by the high-temperature gas-cooled reactor flows into the heat exchange chamber 11 through the high-temperature heat transfer medium inlet 13. Within the heat exchange chamber 11, it first exchanges heat with the high-temperature heat exchanger 3, and then with the cryogenic heat exchanger 2. After the heat exchange is completed, the temperature of the heat transfer medium decreases, flows into the return chamber 12, and then returns to the high-temperature gas-cooled reactor through the cryogenic heat transfer medium outlet 14.

[0036] The steam generator has two independent heat exchange sections: a low-temperature heat exchange section and a high-temperature heat exchange section. In the low-temperature heat exchange section, the water inside the low-temperature heat exchange device 2 is heated into superheated steam (there is no two-phase region when the parameters are above the critical point). The steam temperature output by the low-temperature heat exchange device 2 does not exceed 550℃ to ensure that the wall temperature of the heat exchange tubes in this section is below 550℃. Industrial-grade heat exchange tube materials, such as 15CrMoG and T22, can be used directly; nuclear-grade heat exchange tube materials, such as T22, T91, 304 stainless steel, and 316 stainless steel, and other materials permitted by relevant nuclear-grade standards, can also be used. For the high-temperature heat exchange section, the steam temperature inside the high-temperature heat exchange device 3 is further increased, but not higher than 650°C. The wall temperature of the heat exchange tubes in the high-temperature heat exchange device 3 is not higher than 650°C. Industrial-grade materials that can be used include ferritic materials such as G115 (new martensitic) and T122 (HCM12A), as well as austenitic materials such as TP347H and SUPER304H, or Incoloy 800H and high-nickel-based alloy materials. Nuclear-grade heat exchange tube materials, such as 316 stainless steel and Incoloy 800H materials, and other materials permitted by relevant nuclear-grade standards, can also be used.

[0037] It should be noted that the steam generator can be a subcritical steam generator or a supercritical steam generator, and the heat exchange medium can be water. The critical pressure of water is 22.06 MPa. When the feed water pressure is less than the critical pressure, it is a subcritical steam generator; when the feed water pressure is greater than the critical pressure, it is a supercritical steam generator. The feed water pressure can be selected according to the specific design of the steam generator.

[0038] In this application, the terms "low temperature" and "high temperature" do not refer to a specific temperature range, but rather to the relative temperature of the two heat exchange devices, i.e., the temperature of the heat exchange medium in the high temperature heat exchange device 3 is higher than that in the low temperature heat exchange device 2.

[0039] The subcritical / supercritical steam generator of this invention improves the reliability and flexibility of steam generator operation by incorporating a high-temperature heat exchange device 3 and a low-temperature heat exchange device 2 internally. It can be designed and manufactured according to industrial or nuclear standards, and some of the manufacturing materials can be high-temperature materials that are already widely used in the thermal power field, reducing the manufacturing cost of the steam generator. It can better adapt to market development and is conducive to industrial upgrading and technological innovation. In addition, the subcritical / supercritical steam generator is compatible with existing high-temperature gas-cooled reactors and can achieve seamless integration without requiring changes or modifications to other equipment or systems.

[0040] The subcritical / supercritical steam generator of this invention can be designed according to industrial standards as required. The main design standards include: 1) National Standard (GB) series: GB / T 151 "Heat Exchangers", GB 150 "Pressure Vessels", GB / T 16508 "Shell Boilers"; 2) International standards: ASME BPVC Section I (power boilers), ASME Section VIII (pressure vessels), EN 12952 (EU water tube boilers), EN 12953 (EU shell boilers), PED 2014 / 68 / EU (EU pressure equipment directive), etc.

[0041] This steam generator can also be designed according to nuclear-grade standards upon request. The main design standards include: 1) International Standards: ASME BPVC Section III (ASME Section III Nuclear Power Plant Equipment Construction Guidelines), RCC-M Nuclear Island Mechanical Equipment, KTA Equipment Design Guidelines; 2) Relevant domestic standards: such as NB / T standards.

[0042] In one exemplary embodiment, the design parameters of the subcritical / supercritical steam generator are as follows: The heat exchange power of the steam generator is less than 320MW. The heat transfer medium is helium. The heat exchange medium is water or steam. The inlet temperature of the high-temperature heat transfer medium is less than 700℃. The pressure of the heat transfer medium is less than 8MPa. The feed water pressure can be selected according to the specific design of the steam generator. The feed water temperature is less than 250℃. The steam temperature is less than 600℃.

[0043] For the range of thermal parameters of subcritical / supercritical steam generators, high-temperature materials that are widely used in the field of thermal power generation can be adopted in the structural design. At the same time, mature design and manufacturing experience in the field of thermal power generation can be utilized to reduce the manufacturing cost of steam generators and meet the requirements of market-oriented manufacturing.

[0044] like Figure 1 As shown, in some embodiments, the subcritical / supercritical steam generator has a longitudinal structure, the low-temperature heat exchange device 2 is located below the high-temperature heat exchange device 3, the high-temperature heat transfer medium inlet 13 is arranged opposite to the high-temperature heat exchange device 3, the heat exchange medium in the low-temperature heat exchange device 2 flows in the opposite direction to the heat transfer medium in the heat exchange chamber 11, and the heat exchange medium in the high-temperature heat exchange device 3 flows in the same or opposite direction to the heat transfer medium in the heat exchange chamber 11.

[0045] It should be noted that the low-temperature heat exchanger 2 and the high-temperature heat exchanger 3 can be arranged in the same shell 1, or, depending on the actual situation, the low-temperature heat exchanger 2 and the high-temperature heat exchanger 3 can be set in two separate shells to form independent high-temperature heat exchange equipment and low-temperature heat exchange equipment. In the high-temperature heat exchange equipment, the flow direction of the heat exchange medium and the heat transfer medium is the same or opposite; in the low-temperature heat exchange equipment, the flow direction of the heat exchange medium and the heat transfer medium is opposite.

[0046] Understandably, the low-temperature heat exchanger 2 is arranged in a counter-current manner. This arrangement results in a large heat exchange temperature difference for the steam generator, high heat exchange efficiency, and a small, compact size. The high-temperature heat exchanger 3, on the other hand, can be flexibly arranged in either a counter-current or co-current manner depending on the wall temperature limitations of the heat exchange tubes. For example, if the heat exchange tubes cannot withstand excessively high temperatures due to material limitations, the high-temperature heat exchanger 3 can be arranged in a co-current manner. If high heat exchange efficiency is desired and high-temperature resistant materials are used, a counter-current arrangement can be adopted. The following description uses the counter-current arrangement of the high-temperature heat exchanger 3 as an example.

[0047] In some embodiments, the cryogenic heat exchange device 2 includes a cryogenic inlet connection assembly 21, a cryogenic heat exchange assembly 22, and a cryogenic outlet connection assembly 23. The cryogenic heat exchange assembly 22 is disposed in the heat exchange chamber 11 and is used to exchange heat with the heat transfer medium. The cryogenic inlet connection assembly 21 passes through the housing and is connected to the input end of the cryogenic heat exchange assembly 22. The cryogenic outlet connection assembly 23 passes through the housing and is connected to the output end of the cryogenic heat exchange assembly 22.

[0048] The heat exchange medium input to the low-temperature heat exchanger 2 can be water. The heat exchange medium enters the low-temperature heat exchanger 22 through the low-temperature inlet connection component 21 and exchanges heat with the heat transfer medium. After being heated, the water turns into steam, and the steam is discharged through the low-temperature outlet connection component 23.

[0049] In some embodiments, the low-temperature inlet connection assembly 21 includes a water supply manifold 211, a water supply pipe box 212, and a water supply connection pipe bundle connected in sequence. The water supply manifold 211 is located outside the housing 1, the water supply pipe box 212 is located at the lower end of the housing 1, the water supply pipe box 212 passes through the housing 1, and the water supply connection pipe bundle is located in the heat exchange chamber 11 and connected to the low-temperature heat exchange assembly 22. The heat exchange medium enters the water supply pipe box 212 through the water supply manifold 211, and then enters the low-temperature heat exchange assembly 22 through the water supply connection pipe bundle.

[0050] The cryogenic outlet connection assembly 23 includes a cryogenic steam outlet connection pipe bundle 231, a cryogenic steam outlet pipe box 232, and a cryogenic steam outlet header 233 connected in sequence. The cryogenic steam outlet pipe box 232 is located in the middle of the shell 1. The cryogenic steam outlet connection pipe bundle 231 is located in the heat exchange chamber 11 and connected to the high-temperature heat exchange assembly 32. The cryogenic steam outlet pipe box 232 passes through the shell 1. The cryogenic steam outlet header 233 is located outside the shell 1. The heat exchange medium that has completed heat exchange in the cryogenic heat exchange assembly 22 enters the cryogenic steam outlet pipe box 232 through the cryogenic steam outlet connection pipe bundle 231 and then flows into the cryogenic steam outlet header 233.

[0051] It should be noted that both the low-temperature heat exchanger 2 and the high-temperature heat exchanger 3 can be configured as an integrated structure, with some of the structures manufactured, transported, and installed as a whole. Alternatively, they can be configured as a modular structure, comprising multiple independent module units, each manufactured separately, facilitating transportation and on-site assembly. Furthermore, in the event of a failure, the modular structure allows for the replacement of individual modules, resulting in low maintenance costs and flexible operation and maintenance.

[0052] In one exemplary embodiment, the low-temperature heat exchanger 2 and the high-temperature heat exchanger 3 are modular structures. Except for the manifold structure, there are multiple low-temperature inlet connection components 21, low-temperature heat exchange components 22 and low-temperature outlet connection components 23. Multiple low-temperature heat exchange components 22 are evenly arranged in the heat exchange chamber 11. The water supply manifold 211 is a ring structure and is arranged around the periphery of the shell 1. The water supply manifold 211 is connected to multiple water supply pipe boxes 212 and is used to distribute water to the multiple water supply pipe boxes 212.

[0053] Similarly, there are multiple low-temperature steam outlet pipe boxes 232, and low-temperature steam outlet manifolds 233 are arranged around the periphery of the shell 1 to collect the steam from each low-temperature steam outlet pipe box 232 for mixing. During steam mixing, appropriate measures can be taken to increase steam turbulence to achieve better mixing effect. For example, by adjusting the positional relationship between the low-temperature steam outlet pipe box 232 and the low-temperature steam outlet manifold 233, and designing them to be arranged in an off-center manner, the steam enters the low-temperature steam outlet manifold 233 at a specific angle, such as tangentially, so that the steam rotates and flows circumferentially along the wall of the low-temperature steam outlet manifold 233, increasing the mixing flow of the steam. The steam from different heat exchange modules can be fully mixed, making the temperature of the mixed steam more uniform.

[0054] In some embodiments, the cryogenic inlet connection assembly 21 further includes a detachable water supply pipe section 214 disposed between the water supply manifold 211 and the water supply pipe box 212. The detachable water supply pipe section 214 is detachably connected to both the water supply manifold 211 and the water supply pipe box 212, such as through flange connections, threaded connections, clamp connections, or quick-connect couplings. Due to the high internal pressure of the pipeline, flange connections can be used, ensuring reliable sealing and high pressure resistance. When a fault occurs on the water supply side or maintenance is required, the detachable water supply pipe section 214 can be removed to inspect (including helium leak detection), repair, and plugging of the internal connecting pipe bundle and heat exchange pipes.

[0055] Similarly, such as Figures 4-6 As shown, the cryogenic outlet connection assembly 23 also includes a detachable cryogenic steam outlet side pipe section 234 disposed between the cryogenic steam outlet pipe box 232 and the cryogenic steam outlet header 233. The detachable cryogenic steam outlet side pipe section 234 is detachably connected to both the cryogenic steam outlet pipe box 232 and the cryogenic steam outlet header 233, such as a flange connection. When a fault occurs on the cryogenic steam outlet side or maintenance is required, the detachable cryogenic steam outlet side pipe section 234 can be removed to inspect (including helium leak detection), repair, and plugging activities on the internal pipe bundle and heat exchange tubes.

[0056] In some embodiments, the low-temperature heat exchange assembly 22 includes a low-temperature heat exchange tube 221, a low-temperature support plate 222, and a low-temperature positioning plate 223. The two ends of the low-temperature heat exchange tube 221 are respectively connected to the low-temperature inlet connection assembly 21 and the low-temperature outlet connection assembly 23. There are multiple low-temperature heat exchange tubes 221. The input end of the low-temperature heat exchange tube 221 is connected to the water supply connection pipe bundle, and the output end of the low-temperature heat exchange tube 221 is connected to the low-temperature steam outlet connection pipe bundle 231.

[0057] Both the cryogenic support plate 222 and the cryogenic positioning plate 223 are fixedly installed inside the heat exchange chamber 11. They can be installed on the inner wall of the shell 1 or on the heat insulation device 4. The cryogenic support plate 222 is located above the cryogenic positioning plate 223 and serves as a support. The upper end of the cryogenic heat exchange tube 221 is connected to the cryogenic support plate 222. This arrangement reduces the difficulty of arranging the cryogenic heat exchange tube 221 and the cryogenic steam outlet connecting tube bundle 231. The cryogenic positioning plate 223 is provided with a cryogenic guide hole, through which the lower end of the cryogenic heat exchange tube 221 passes. When the steam generator is running in a hot state, the cryogenic heat exchange tube 221 will expand. Since the upper end of the cryogenic heat exchange tube 221 is connected to the cryogenic support plate 222, the cryogenic heat exchange tube 221 will expand downward. Since the lower end of the cryogenic heat exchange tube 221 has no rigid connection, the impact is minimal. Constrained by the cryogenic positioning plate 223, the cryogenic heat exchange tube 221 will not sway, ensuring the stability of the structure. To improve the reliability of the steam generator, the cryogenic heat exchange tube 221 and the connecting pipes at both ends can be made of the same material, and preferably a single, continuous heat exchange tube. This reduces the number of butt welds on the cryogenic heat exchange tube 221. In actual project implementation, the positions of the cryogenic support plate 222 and the cryogenic positioning plate 223 can be interchanged according to the structural layout requirements.

[0058] Because the cryogenic heat exchange tube 221 is relatively long, a spiral tube structure can be adopted to minimize the height of the steam generator shell 1. This ensures the length of the heat exchange tube while effectively reducing the friction damping of the heat exchange medium. The spiral tube structure should be arranged in an ideal manner, i.e., the ratio of the spiral tube bundle diameter to the number of spiral tube heads is a constant. The spiral diameter should be set to take into account the development of in-service inspection technology so that in-service inspection of the cryogenic heat exchange tube 221 can be carried out in the future.

[0059] The cryogenic heat exchange assembly 22 also includes a throttling element (not shown). This throttling element is located at the inlet end of the cryogenic heat exchange tube 221. The throttling element provides throttling damping, balancing the flow resistance differences among the heat exchange tubes by adding uniform local resistance, achieving uniform flow distribution, eliminating thermal deviation and flow bias, and ensuring stable flow of the heat exchange medium while also regulating flow. Since the throttling element is only installed at the inlet of the cryogenic heat exchange tube 221, blockage of the throttling element will not cause a significant increase in the tube wall temperature (limited by the temperature of the heat transfer medium at the inlet end of the cryogenic heat exchange device 2), thus avoiding tube rupture accidents. The structure and arrangement of the throttling element are mature existing technologies and will not be described further.

[0060] The structure of the high-temperature heat exchanger 3 is similar to that of the low-temperature heat exchanger 2. Specifically, the high-temperature heat exchanger 3 includes a high-temperature inlet connection assembly 31, a high-temperature heat exchange assembly 32, and a high-temperature outlet connection assembly 33. The high-temperature heat exchange assembly 32 is disposed in the heat exchange chamber 11 and is used to exchange heat with the heat transfer medium. The high-temperature inlet connection assembly 31 passes through the shell 1 and is connected to the input end of the high-temperature heat exchange assembly 32. The high-temperature outlet connection assembly 33 passes through the shell 1 and is connected to the output end of the high-temperature heat exchange assembly 32. The low-temperature outlet connection assembly 23 is connected to the high-temperature inlet connection assembly 31.

[0061] The heat exchange medium that has undergone heat exchange in the low-temperature heat exchanger 2 passes through the low-temperature outlet connection component 23 and the high-temperature inlet connection component 31 in sequence and enters the high-temperature heat exchanger 3 for heat exchange again, further increasing the temperature of the heat exchange medium. After the heat exchange is completed, it flows into the steam turbine through the high-temperature outlet connection component 33 for power generation, or it can enter other energy conversion equipment for energy utilization.

[0062] like Figures 4-6 As shown, in some embodiments, the high-temperature inlet connection assembly 31 includes a steam inlet header 311, a steam inlet pipe box 312, and a steam inlet connection pipe bundle 313 connected in sequence. The steam inlet header 311 is located outside the housing 1 and in the middle of the housing 1. The steam inlet pipe box 312 passes through the housing 1. The steam inlet connection pipe bundle 313 is located in the heat exchange chamber 11 and connected to the high-temperature heat exchange assembly 32. The heat exchange medium enters the steam inlet pipe box 312 through the steam inlet header 311 and then enters the high-temperature heat exchange assembly 32 through the steam inlet connection pipe bundle 313.

[0063] The high-temperature outlet connection assembly 33 includes a high-temperature steam outlet connection pipe bundle 331, a high-temperature steam outlet pipe box 332, and a high-temperature steam outlet header 333 connected in sequence. The high-temperature steam outlet connection pipe bundle 331 is located in the heat exchange chamber 11 and is connected to the high-temperature heat exchange assembly 32. The high-temperature steam outlet pipe box 332 passes through the shell 1. The high-temperature steam outlet header 333 is located outside the shell 1 and its height is approximately equal to the height of the high-temperature heat transfer medium inlet 13. The heat transfer medium that has completed secondary heat exchange in the high-temperature heat exchange assembly 32 enters the high-temperature steam outlet pipe box 332 through the high-temperature steam outlet connection pipe bundle 331 and then flows into the steam turbine through the high-temperature steam outlet header 333.

[0064] In one exemplary embodiment, the high-temperature heat exchange device 3 has a modular structure. Except for the manifold structure, there are multiple high-temperature inlet connection components 31, high-temperature heat exchange components 32, and high-temperature outlet connection components 33. The multiple high-temperature heat exchange components 32 are evenly arranged in the heat exchange chamber 11. The steam inlet manifold 311 has an annular structure and is arranged around the periphery of the shell 1. The steam inlet manifold 311 is connected to multiple steam inlet pipe boxes 312 and is used to distribute steam to the multiple steam inlet pipe boxes 312.

[0065] Similarly, there are multiple high-temperature steam outlet pipe boxes 332, and high-temperature steam outlet headers 333 are arranged around the periphery of the shell 1 to collect the steam from each high-temperature steam outlet pipe box 332 for mixing. During steam mixing, appropriate measures can be taken to increase steam turbulence to achieve better mixing effect. For example, by adjusting the positional relationship between the high-temperature steam outlet pipe box 332 and the high-temperature steam outlet header 333, and designing them to be arranged in an off-center manner, the steam enters the high-temperature steam outlet header 333 at a specific angle, such as tangential entry, so that the steam rotates and flows circumferentially along the wall of the high-temperature steam outlet header 333, increasing the mixing flow of the steam. The steam from different heat exchange modules can be fully mixed, making the temperature of the mixed steam more uniform.

[0066] In some embodiments, the high-temperature inlet connection assembly 31 further includes a detachable steam inlet-side pipe section 314 disposed between the steam inlet header 311 and the steam inlet pipe box 312. The detachable steam inlet-side pipe section 314 is detachably connected to both the steam inlet header 311 and the steam inlet pipe box 312, using methods such as flange connections, threaded connections, clamp connections, or quick-connect couplings. Due to the high internal pressure of the pipeline, flange connections can be used, ensuring reliable sealing and high pressure resistance. When a fault occurs on the steam inlet side or maintenance is required, the detachable steam inlet-side pipe section can be removed to inspect (including helium leak detection), repair, and plugging of the internal connecting tube bundle and heat exchange tubes.

[0067] Similarly, the high-temperature outlet connection assembly 33 also includes a detachable high-temperature steam outlet side pipe section 334 disposed between the high-temperature steam outlet pipe box 332 and the high-temperature steam outlet header 333. The detachable high-temperature steam outlet side pipe section 334 is detachably connected to both the high-temperature steam outlet pipe box 332 and the high-temperature steam outlet header 333, such as through flange connections. When a fault occurs on the high-temperature steam outlet side or maintenance is required, the detachable low-temperature steam outlet side pipe section 234 can be removed to inspect (including helium leak detection), repair, and plugging activities on the internal pipe bundle and heat exchange tubes.

[0068] The high-temperature heat exchange assembly 32 includes a high-temperature heat exchange tube 321, a high-temperature support plate 322, and a high-temperature positioning plate 323. The two ends of the high-temperature heat exchange tube 321 are respectively connected to the high-temperature inlet connection assembly 31 and the high-temperature outlet connection assembly 33. There are multiple high-temperature heat exchange tubes 321. The input end of the high-temperature heat exchange tube 321 is connected to the steam inlet connection tube bundle 313, and the output end is connected to the high-temperature steam outlet connection tube bundle 331.

[0069] Both the high-temperature support plate 322 and the high-temperature positioning plate 323 are fixedly installed in the heat exchange chamber 11. The upper end of the high-temperature heat exchange tube 321 is connected to the high-temperature support plate 322. The high-temperature positioning plate 323 is provided with a high-temperature guide hole, and the lower end of the high-temperature heat exchange tube 321 passes through the high-temperature guide hole.

[0070] Both the high-temperature support plate 322 and the high-temperature positioning plate 323 are fixedly installed inside the heat exchange chamber 11. They can be installed on the inner wall of the shell 1 or on the heat insulation device 4. The high-temperature support plate 322 is located above the high-temperature positioning plate 323, serving a supporting function. The upper end of the high-temperature heat exchange tube 321 is connected to the high-temperature support plate 322. This arrangement reduces the difficulty of arranging the high-temperature heat exchange tube 321 and the high-temperature steam outlet connecting tube bundle 331. The high-temperature positioning plate 323 is provided with a high-temperature guide hole, through which the lower end of the high-temperature heat exchange tube 321 passes. When the steam generator is running in a hot state, the high-temperature heat exchange tube 321 will expand. Since the upper end of the high-temperature heat exchange tube 321 is connected to the high-temperature support plate 322, the high-temperature heat exchange tube 321 will expand downwards. Because the lower end of the high-temperature heat exchange tube 321 has no rigid connection, the impact is minimal. Constrained by the high-temperature positioning plate 323, the high-temperature heat exchange tube 321 will not sway, ensuring the stability of the structure. To improve the reliability of the steam generator, the high-temperature heat exchange tube 321 and the connecting pipes at both ends can be made of the same material, and preferably a single, continuous heat exchange tube. This reduces the number of butt welds on the high-temperature heat exchange tube 321. In actual project implementation, the positions of the high-temperature support plate 322 and the high-temperature positioning plate 323 can be interchanged according to the structural layout requirements.

[0071] The high-temperature heat exchanger tube 321 can also adopt a spiral tube structure, which can effectively reduce the friction damping of the heat exchange medium while ensuring the length of the heat exchanger tube. The spiral tube structure should be arranged in an ideal manner, that is, the ratio of the spiral tube bundle diameter to the number of spiral tube heads is a constant value. The spiral diameter should be set in a way that takes into account the development of in-service inspection technology so that in-service inspection of the low-temperature heat exchanger tube 221 can be carried out in the future.

[0072] In one exemplary embodiment, the high-temperature support plate 322, the high-temperature positioning plate 323, and the low-temperature support plate 222 are mounted on the fixed cylinder 41 via connectors. The low-temperature positioning plate 223 is mounted on the inner wall of the housing 1. The fixed cylinder 41 is configured as a segmented structure, divided into upper and lower parts, with an expansion absorption structure between them. For example, the two parts are inserted together, and a corrugated pipe is provided at the connection point, thereby absorbing the thermal expansion difference caused by different support positions. In some embodiments, the steam generator further includes a reheating device (not shown), which is disposed in the heat exchange chamber 11. The reheating device is located on the side of the high-temperature heat exchange device 3 away from the low-temperature heat exchange device 2, or between the high-temperature heat exchange device 3 and the low-temperature heat exchange device 2. It is understood that the reheating device can be disposed either above the high-temperature heat exchange device 3 or between the high-temperature heat exchange device 3 and the low-temperature heat exchange device 2. The specific arrangement is determined according to thermal calculations. The reheating device is connected to the steam turbine to reheat the wet steam flowing out of the steam turbine, thereby further improving the cycle thermal efficiency of the steam generator.

[0073] The reheat unit includes a reheater, a reheat steam inlet pipe, and a reheat steam outlet pipe. One end of the reheat steam inlet pipe is connected to the reheat steam pipe of the steam turbine, and the other end passes through the shell 1 and is connected to the input end of the reheater. One end of the reheat steam outlet pipe is connected to the output end of the reheater, and the other end passes through the shell 1 and is connected to the reheat steam pipe of the steam turbine. The wet steam in the steam turbine enters the reheater through the secondary side reheat steam pipe and the reheat steam inlet pipe. After being reheated by the heat transfer medium, it returns to the steam turbine through the reheat steam outlet pipe and the reheat steam pipe to generate electricity.

[0074] In some embodiments, the subcritical / supercritical steam generator further includes a heat insulation device 4, which is disposed inside the shell 1. The heat insulation device 4 defines a heat exchange chamber 11 inside the heat insulation device 4. The heat insulation device 4 and the shell 1 define a return chamber 12. The heat insulation device 4 is disposed at the junction of the high-temperature heat transfer medium and the low-temperature heat transfer medium to reduce the heat transfer from the high-temperature heat transfer medium to the low-temperature heat transfer medium and reduce heat loss.

[0075] The heat insulation device 4 includes a fixed cylinder 41 and a heat insulation layer 42 disposed on the fixed cylinder 41. The fixed cylinder 41 is connected to the shell 1. The upper end of the fixed cylinder 41 is closed and the lower end is open. The cavity inside the fixed cylinder 41 is the heat exchange cavity 11. The remaining cavities inside the shell 1 are the return cavity 12. The heat transfer medium flows into the top of the heat exchange cavity 11 through the high temperature heat transfer medium inlet 13 and flows from top to bottom. After flowing to the bottom, it flows upward along the annular cavity between the fixed cylinder 41 and the shell 1. Under the action of the air supply device, it flows out from the low temperature heat transfer medium outlet 14.

[0076] The fixed cylinder 41 is connected to the inner wall of the shell 1 via a connecting structure. The heat insulation layer 42 is disposed on the inner wall surface and / or outer wall surface of the fixed cylinder 41. The heat insulation layer 42 can be disposed on one side of the fixed cylinder 41 or on both sides of the fixed cylinder 41 to improve the heat insulation effect. The heat insulation layer 42 can be one or more of inorganic fibers, microporous materials, nanomaterials, and metal reflective layers, such as aluminum silicate fiber, high silica, quartz fiber, aerogel insulation felt, micro-nano microporous insulation board, etc.

[0077] The fixed cylinder 41 is provided with multiple through holes for connecting pipe bundles or headers to pass through. The high-temperature steam outlet connecting pipe bundle 331 passes through the through holes on the fixed cylinder 41 and is connected to the high-temperature steam outlet header 333. An expansion absorption structure, such as a corrugated pipe structure, is provided between the high-temperature steam outlet header 333 and the fixed cylinder 41. The thermal expansion difference between the high-temperature steam outlet pipe box 332 and the fixed cylinder 41 is absorbed by the expansion absorption structure.

[0078] In some embodiments, the steam generator further includes a high-temperature heat transfer medium conveying device 5, which is used to realize the input and output of the heat transfer medium. Specifically, the high-temperature heat transfer medium conveying device 5 includes a hot gas duct 51 and a duct shell 52. Both the hot gas duct 51 and the duct shell 52 are tubular structures. A through hole is provided on the shell 1. One end of the duct shell 52 is connected to the shell 1 and corresponds to the through hole on the shell 1. The other end of the duct shell 52 is connected to the pressure vessel of the high-temperature cooling end. The inner cavity of the duct shell 52 forms a heat transfer medium channel. The input end of the hot gas duct 51 is connected to the core of the high-temperature gas-cooled reactor. The output end of the hot gas duct 51 passes through the heat transfer medium channel and extends into the interior of the shell 1 and communicates with the heat exchange chamber 11.

[0079] The high-temperature heat transfer medium inlet 13 is formed inside the hot gas duct 51, and the low-temperature heat transfer medium outlet 14 is formed between the hot gas duct 51 and the duct shell 52. The high-temperature heat transfer medium generated by the core of the high-temperature gas-cooled reactor enters the heat exchange chamber 11 through the hot gas duct 51. After heat exchange, the low-temperature heat transfer medium returns to the high-temperature gas-cooled reactor through the return chamber 12 and the low-temperature heat transfer medium outlet 14.

[0080] The high-temperature heat transfer medium conveying device 5 also includes a high-temperature medium homogenizing component 53. This component ensures the heat transfer medium is evenly discharged from the hot gas duct 51 into the heat exchange chamber 11, reducing the flow velocity of the heat transfer medium at the top of the heat exchange chamber 11 and preventing it from directly impacting the high-temperature steam outlet pipe box 332 due to excessive flow velocity. Specifically, the high-temperature medium homogenizing component 53 is disposed within the heat exchange chamber 11. It includes a connecting cylinder 531 and an outlet section 532. One end of the connecting cylinder 531 is connected to the hot gas duct 51, and the other end is connected to the outlet section 532. The inner diameter of the connecting cylinder 531 gradually increases from the hot gas duct 51 towards the outlet section 532. The outlet section 532 includes a cylinder and a cover. The inner diameter of the cylinder remains constant in its axial direction. One end of the cylinder is connected to the connecting cylinder 531, and the other end is connected to the cover. The cover has a hemispherical structure, and both the cylinder and the cover are provided with outlet holes. The heat transfer medium flows into the heat exchange chamber 11 through these outlet holes.

[0081] In some embodiments, the steam generator further includes an air supply device, which includes a fan assembly 61 and a flow guide assembly. The fan assembly 61 is connected to the top of the housing 1 and is used to provide a pressure head for the flow of the heat transfer medium. The flow guide assembly is disposed in the return chamber 12 and is used to guide the heat transfer medium in the return chamber 12 to the fan assembly 61. The low-temperature heat transfer medium in the return chamber 12 that has undergone heat exchange flows to the fan assembly 61 through the flow guide assembly, and then returns to the return chamber 12 through the fan assembly 61 and flows to the low-temperature heat transfer medium outlet 14.

[0082] The fan assembly 61 includes a fan housing 611, a mounting bracket 612, and a fan body (not shown). The fan housing 611 is connected to the top of the housing 1, and the top of the housing 1 is open. The inner cavity of the fan housing 611 communicates with the return cavity 12. The mounting bracket 612 is located at the connection between the fan housing 611 and the housing 1, and the mounting bracket 612 is detachably connected to the housing 1. The fan body is mounted on the mounting bracket 612. The fan body has a volute. The flow guiding assembly guides the heat transfer medium in the return cavity 12 into the volute, and then flows out through the volute, returning to the return cavity 12, and finally flowing to the low-temperature heat transfer medium outlet 14.

[0083] The flow guiding assembly includes a baffle plate 621, a heat transfer medium riser pipe 622, and a fan inlet header 623. The baffle plate 621 is annular and disposed within the return cavity 12. The baffle plate 621 is positioned between the fixed cylinder 41 and the inner wall of the housing 1. Multiple flow guiding holes are provided on the baffle plate 621. The fan inlet header 623 is positioned above the heat insulation device 4. One end of the heat transfer medium riser pipe 622 is connected to the baffle plate 621 and corresponds to the flow guiding holes. The other end of the heat transfer medium riser pipe 622... The output end of the fan inlet header 623 is connected to the input end of the fan inlet header 623. The output end of the fan inlet header 623 is arranged opposite to the fan body. The heat transfer medium in the return chamber 12 enters the heat transfer medium riser pipe 622 through the guide hole and is collected in the fan inlet header 623 through the heat transfer medium riser pipe 622. The output end of the fan inlet header 623 is arranged opposite to the fan body. The heat transfer medium enters the fan body and flows out of the fan body in sequence through the return chamber 12 and the low temperature heat transfer medium outlet 14.

[0084] A corrugated pipe can be installed between the baffle plate 621 and the heat transfer medium riser pipe 622 for transition. One end of the corrugated pipe is connected to the baffle plate 621, and the other end is connected to the lower end of the heat transfer medium riser pipe 622. The corrugated pipe can absorb the thermal expansion difference between the heat transfer medium riser pipe 622 and the baffle plate 621.

[0085] The following describes the complete working process of the steam generator according to an embodiment of the present invention.

[0086] High-temperature helium gas generated in the core of the high-temperature gas-cooled reactor enters the high-temperature medium homogenization assembly 53 through the hot gas duct 51. After being decelerated by the high-temperature medium homogenization assembly 53, it flows evenly into the heat exchange chamber 11 through the outlet. The high-temperature helium gas first exchanges heat with the steam in the high-temperature heat exchange device 3, and then exchanges heat with the water in the low-temperature heat exchange device 2. The temperature of the helium gas after heat exchange decreases to form low-temperature helium gas. The low-temperature helium gas passes through the annular cavity between the fixed cylinder 41 and the shell 1 to reach the baffle plate 621, and then flows through the guide hole on the baffle plate 621 and the heat transfer medium riser pipe 622 into the blower inlet header 623. The blower inlet header 623 introduces the low-temperature helium gas into the blower. After being pressurized by the blower, it returns to the return chamber 12, and then returns to the core through the annular cavity between the hot gas duct 51 and the duct shell 52, completing the cycle.

[0087] The initial heat exchange medium is water. The water sequentially passes through the feedwater header 211, feedwater pipe box 212, and feedwater connecting pipe bundle into the low-temperature heat exchange tube 221, where it exchanges heat with high-temperature helium gas. The water is heated to form steam. The steam then sequentially passes through the low-temperature steam outlet connecting pipe bundle 231, low-temperature steam outlet pipe box 232, low-temperature steam outlet header 233, steam inlet header 311, steam inlet pipe box 312, and steam inlet connecting pipe bundle 313 into the high-temperature heat exchange tube 321. Secondary heat exchange occurs in the high-temperature heat exchange tube 321, forming high-temperature steam. The high-temperature steam sequentially passes through the high-temperature steam outlet connecting pipe bundle 331, high-temperature steam outlet pipe box 332, and high-temperature steam outlet header 333 into the steam turbine to generate electricity. The steam condenses into water and flows back into the feedwater header 211, completing the cycle.

[0088] The subcritical / supercritical high-temperature gas-cooled reactor steam generator of this invention has the following advantages or features: 1. It can be seamlessly integrated with existing high-temperature gas-cooled reactor technology without requiring changes or modifications to other equipment or systems.

[0089] 2. It can be designed and manufactured according to conventional industrial standards or nuclear-grade standards.

[0090] 3. The steam generator is divided into a high-temperature heat exchange section and a low-temperature heat exchange section to reduce the outlet steam temperature deviation and improve the reliability and flexibility of steam generation operation.

[0091] 4. High-temperature materials that have been developed and widely used in the field of thermal power generation can be used.

[0092] 5. Mature experience in the field of thermal power generation can be utilized to design and manufacture steam generators, thereby reducing manufacturing costs.

[0093] The high-temperature gas-cooled reactor of this invention includes a pressure vessel, a reactor core, and a steam generator as described in any of the above embodiments. The reactor core is disposed within the pressure vessel, and the steam generator is connected to the pressure vessel, with the steam generator positioned lower than the reactor core. The high-temperature gas-cooled reactor of this invention has low manufacturing costs, can better adapt to market development, and is conducive to industrial upgrading and technological innovation.

[0094] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0095] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include at least one of those features.

[0096] In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise expressly and specifically limited.

[0097] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0098] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0099] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0100] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A subcritical / supercritical steam generator, characterized in that, The steam generator includes: The shell has a heat exchange chamber and a reflux chamber that are connected. The shell is provided with a high-temperature heat transfer medium inlet and a low-temperature heat transfer medium outlet. The high-temperature heat transfer medium inlet, the heat exchange chamber, the reflux chamber and the low-temperature heat transfer medium outlet are connected in sequence. A low-temperature heat exchanger and a high-temperature heat exchanger are provided, with at least a portion of the low-temperature heat exchanger and at least a portion of the high-temperature heat exchanger disposed within the heat exchange chamber. The low-temperature heat exchanger and the high-temperature heat exchanger are arranged axially spaced along the shell, with the high-temperature heat exchanger adjacent to the high-temperature heat transfer medium inlet. The output end of the low-temperature heat exchanger is connected to the input end of the high-temperature heat exchanger. The heat transfer medium flowing into the heat exchange chamber through the high-temperature heat transfer medium inlet exchanges heat with the high-temperature heat exchanger and the low-temperature heat exchanger in sequence, and flows out through the reflux chamber from the low-temperature heat transfer medium outlet.

2. The subcritical / supercritical steam generator according to claim 1, characterized in that, The design parameters of the steam generator satisfy: Heat exchange capacity less than 320MW; The temperature of the heat transfer medium at the inlet of the high-temperature heat transfer medium is less than 700°C. The pressure of the heat transfer medium inside the shell is less than 8 MPa; The temperature of the heat exchange medium at the input end of the low-temperature heat exchange device is less than 250°C. The temperature of the heat exchange medium in the low-temperature heat exchanger and the high-temperature heat exchanger is less than 600°C.

3. The subcritical / supercritical steam generator according to claim 1, characterized in that, The low-temperature heat exchanger is located below the high-temperature heat exchanger. The heat exchange medium on the inner tube side of the low-temperature heat exchanger flows in the opposite direction to the heat transfer medium on the inner shell side of the heat exchange cavity. The heat exchange medium on the inner tube side of the high-temperature heat exchanger flows in the same or opposite direction to the heat transfer medium on the inner shell side of the heat exchange cavity.

4. The subcritical / supercritical steam generator according to claim 1, characterized in that, The cryogenic heat exchange device includes a cryogenic inlet connection assembly, a cryogenic heat exchange assembly, and a cryogenic outlet connection assembly. The cryogenic heat exchange assembly is disposed inside the heat exchange chamber. The cryogenic inlet connection assembly passes through the housing and is connected to the input end of the cryogenic heat exchange assembly. The cryogenic outlet connection assembly passes through the housing and is connected to the output end of the cryogenic heat exchange assembly.

5. The subcritical / supercritical steam generator according to claim 4, characterized in that, The low-temperature inlet connection assembly includes a water supply manifold, a water supply pipe box, and a water supply connection pipe bundle connected in sequence. The water supply manifold is located outside the housing, the water supply pipe box passes through the housing, and the water supply connection pipe bundle is located inside the heat exchange cavity and connected to the low-temperature heat exchange assembly. The cryogenic outlet connection assembly includes a cryogenic steam outlet connection tube bundle, a cryogenic steam outlet tube box, and a cryogenic steam outlet header connected in sequence. The cryogenic steam outlet connection tube bundle is located inside the heat exchange cavity and connected to the high-temperature heat exchange assembly. The cryogenic steam outlet tube box passes through the housing, and the cryogenic steam outlet header is located outside the housing.

6. The subcritical / supercritical steam generator according to claim 5, characterized in that, The low-temperature inlet connection assembly also includes a detachable water supply side pipe section disposed between the water supply manifold and the water supply pipe box. The cryogenic outlet connection assembly also includes a detachable cryogenic steam outlet side pipe section disposed between the cryogenic steam outlet pipe box and the cryogenic steam outlet header.

7. The subcritical / supercritical steam generator according to claim 4, characterized in that, The low-temperature heat exchange assembly includes a low-temperature heat exchange tube, a low-temperature support plate, and a low-temperature positioning plate. The two ends of the low-temperature heat exchange tube are respectively connected to the low-temperature inlet connection assembly and the low-temperature outlet connection assembly. The low-temperature support plate and the low-temperature positioning plate are both fixedly installed inside the heat exchange cavity. The upper end of the low-temperature heat exchange tube is connected to the low-temperature support plate, and the low-temperature positioning plate is provided with a low-temperature guide hole, through which the lower end of the low-temperature heat exchange tube passes; or, the lower end of the low-temperature heat exchange tube is connected to the low-temperature support plate, the low-temperature positioning plate is provided with a low-temperature guide hole, and the upper end of the low-temperature heat exchange tube passes through the low-temperature guide hole.

8. The subcritical / supercritical steam generator according to claim 7, characterized in that, The cryogenic heat exchange assembly also includes a throttling element disposed at the inlet end of the cryogenic heat exchange tube, and the throttling element is configured to provide throttling damping to ensure stable flow of the heat exchange medium.

9. The subcritical / supercritical steam generator according to claim 1, characterized in that, The high-temperature heat exchange device includes a high-temperature inlet connection assembly, a high-temperature heat exchange assembly, and a high-temperature outlet connection assembly. The high-temperature heat exchange assembly is disposed inside the heat exchange chamber. The high-temperature inlet connection assembly passes through the housing and is connected to the input end of the high-temperature heat exchange assembly. The high-temperature outlet connection assembly passes through the housing and is connected to the output end of the high-temperature heat exchange assembly. The low-temperature outlet connection assembly is connected to the high-temperature inlet connection assembly.

10. The subcritical / supercritical steam generator according to claim 9, characterized in that, The high-temperature inlet connection assembly includes a steam inlet header, a steam inlet pipe box, and a steam inlet connection pipe bundle connected in sequence. The steam inlet header is located outside the housing, the steam inlet pipe box passes through the housing, and the steam inlet connection pipe bundle is located inside the heat exchange cavity and connected to the high-temperature heat exchange assembly. The high-temperature outlet connection assembly includes a high-temperature steam outlet connection tube bundle, a high-temperature steam outlet tube box, and a high-temperature steam outlet header connected in sequence. The high-temperature steam outlet connection tube bundle is located inside the heat exchange cavity and connected to the high-temperature heat exchange assembly. The high-temperature steam outlet tube box passes through the housing, and the high-temperature steam outlet header is located outside the housing.

11. The subcritical / supercritical steam generator according to claim 10, characterized in that, The high-temperature inlet connection assembly also includes a detachable pipe section on the steam inlet side disposed between the steam inlet header and the steam inlet pipe box; The high-temperature outlet connection assembly also includes a detachable pipe section on the high-temperature steam outlet side disposed between the high-temperature steam outlet pipe box and the high-temperature steam outlet header.

12. The subcritical / supercritical steam generator according to claim 9, characterized in that, The high-temperature heat exchange assembly includes a high-temperature heat exchange tube, a high-temperature support plate, and a high-temperature positioning plate. The two ends of the high-temperature heat exchange tube are respectively connected to the high-temperature inlet connection assembly and the high-temperature outlet connection assembly. The high-temperature support plate and the high-temperature positioning plate are both fixedly installed inside the heat exchange cavity. The upper end of the high-temperature heat exchange tube is connected to the high-temperature support plate, and the high-temperature positioning plate is provided with a high-temperature guide hole, through which the lower end of the high-temperature heat exchange tube passes; or, the lower end of the high-temperature heat exchange tube is connected to the high-temperature support plate, and the high-temperature positioning plate is provided with a high-temperature guide hole, through which the upper end of the high-temperature heat exchange tube passes.

13. The subcritical / supercritical steam generator according to any one of claims 1-12, characterized in that, It also includes a reheating device, which is disposed in the heat exchange chamber. The reheating device is located on the side of the high-temperature heat exchange device away from the low-temperature heat exchange device, or between the high-temperature heat exchange device and the low-temperature heat exchange device. The reheating device is connected to the steam turbine to reheat the wet steam flowing out of the steam turbine.

14. The subcritical / supercritical steam generator according to claim 13, characterized in that, The reheating device includes a reheater, a reheat steam inlet pipe, and a reheat steam outlet pipe. One end of the reheat steam inlet pipe is connected to the reheat steam pipe of the steam turbine, and the other end passes through the casing and is connected to the input end of the reheater. One end of the reheat steam outlet pipe is connected to the output end of the reheater, and the other end passes through the casing and is connected to the reheat steam pipe of the steam turbine.

15. The subcritical / supercritical steam generator according to any one of claims 1-12, characterized in that, It also includes a heat insulation device disposed within the housing, the heat insulation device defining the heat exchange cavity inside, and the heat insulation device and the housing defining the reflux cavity.

16. The subcritical / supercritical steam generator according to claim 15, characterized in that, The heat insulation device includes a fixed cylinder and a heat insulation layer. The fixed cylinder is connected to the shell. The upper end of the fixed cylinder is closed and the lower end is open. The heat insulation layer is disposed on the inner wall surface and / or outer wall surface of the fixed cylinder.

17. The subcritical / supercritical steam generator according to any one of claims 1-12, characterized in that, It also includes a high-temperature heat transfer medium conveying device, which includes a hot gas duct and a duct shell. The duct shell is connected to the housing and forms a heat transfer medium channel. The hot gas duct passes through the heat transfer medium channel and communicates with the heat exchange chamber. The high-temperature heat transfer medium inlet is formed inside the hot gas duct, and the low-temperature heat transfer medium outlet is formed between the hot gas duct and the duct shell.

18. The subcritical / supercritical steam generator according to claim 17, characterized in that, The high-temperature heat transfer medium conveying device further includes a high-temperature medium homogenizing component, which is disposed in the heat exchange chamber. The high-temperature medium homogenizing component includes a connecting cylinder and an air outlet. One end of the connecting cylinder is connected to the hot gas duct, and the other end is connected to the air outlet. The air outlet is provided with multiple air outlet holes.

19. The subcritical / supercritical steam generator according to any one of claims 1-12, characterized in that, It also includes an air supply device, which includes a fan assembly and a flow guide assembly. The fan assembly is connected to the top of the housing and provides a pressure head for the flow of the heat transfer medium. The flow guide assembly is disposed in the return cavity and is configured to guide the heat transfer medium in the return cavity to the fan assembly.

20. The subcritical / supercritical steam generator according to claim 19, characterized in that, The fan assembly includes a fan housing, a mounting frame, and a fan body. The fan housing is connected to the top of the housing, and the inner cavity of the fan housing communicates with the return cavity. The mounting frame is disposed at the connection between the fan housing and the housing, and the fan body is disposed on the mounting frame.

21. The subcritical / supercritical steam generator according to claim 20, characterized in that, The flow guiding assembly includes a baffle plate, a heat transfer medium riser pipe, and a fan inlet header. The baffle plate is annular and disposed within the reflux chamber. The baffle plate has flow guiding holes. One end of the heat transfer medium riser pipe is connected to the baffle plate and corresponds to the flow guiding holes. The other end of the heat transfer medium riser pipe is connected to the input end of the fan inlet header. The output end of the fan inlet header is arranged opposite to the fan body. The heat transfer medium enters the fan body through the fan inlet header, flows out of the fan body, and then flows out sequentially through the reflux chamber and the low-temperature heat transfer medium outlet.

22. A high-temperature gas-cooled reactor, characterized in that, The reactor includes a pressure vessel, a reactor core, and a steam generator according to any one of claims 1-21, wherein the reactor core is disposed within the pressure vessel, the steam generator is connected to the pressure vessel, and the steam generator is positioned below the reactor core.

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