Steam generator and steam generator simulation structure

Abstract

The invention relates to a steam generator and a steam generator simulation structure. The external downcomer can be formed by directly bending and welding a standard pipe without customizing a special-shaped structure matched with the annular gap, so that the manufacturing cost is reduced. When the external downcomer breaks down, the external downcomer can be directly and independently maintained or replaced, core components such as the shell and the heat transfer pipe do not need to be disassembled, the risk that the core components are damaged in the disassembling process is reduced, and the maintenance cost is reduced. In addition, a descending channel with an annular gap is adopted, the coaxiality and the gap uniformity of the shell and the cylinder need to be strictly controlled, and multiple times of calibration and debugging need to be carried out; the external downcomer only needs to fix two end interfaces, the assembly process is simplified, and the test preparation period is shortened. Meanwhile, parameters such as the pipe diameter and the length of the external downcomer can be flexibly adjusted, the main body structure of the shell does not need to be changed, contrast tests of different circulation parameters can be conveniently carried out, the test period is shortened, data monitoring in the test process is more direct, test errors caused by a complex structure are reduced, and repeated test cost is reduced.

Description

Technical Field

[0001] This application relates to the field of nuclear power technology, and in particular to steam generators and steam generator simulation structures. Background Technology

[0002] Steam generators, as crucial equipment in the industrial field, are widely used in many industries such as power, chemical, petroleum, and metallurgy. In nuclear power plants, steam generators play a central role, serving as the key link between the primary and secondary loops of the nuclear reactor. They are responsible for transferring the heat generated by the reactor core to the working fluid in the secondary loop, vaporizing the working fluid into steam, and then driving the steam turbine generator set to generate electricity. The stability and reliability of their operation directly affect the safe and economical operation of the nuclear power plant.

[0003] The working principle of a steam generator is based on a heat exchange process. Taking a common steam generator used in a pressurized water reactor nuclear power plant as an example, the high-temperature, high-pressure coolant from the reactor circulates in the primary loop and enters the heat transfer tubes of the steam generator. Through the tube walls, it transfers heat to the water in the secondary loop. The water in the secondary loop absorbs heat, gradually heats up, and vaporizes, eventually forming high-temperature, high-pressure steam, which drives the turbine to rotate, thereby driving the generator to generate electricity.

[0004] The operational stability of steam generators has a significant impact on the safety, reliability, and economic benefits of nuclear power plants, and the thermo-hydraulic performance of steam generators is a key factor in ensuring the safe and stable operation of the equipment. Among related technologies, the testing cost of steam generators is relatively high. Summary of the Invention

[0005] Therefore, it is necessary to provide a steam generator and a steam generator simulation structure to address the problem of high testing costs associated with existing steam generators.

[0006] A steam generator, the steam generator comprising:

[0007] The shell has internal flow channels and multiple heat transfer tubes;

[0008] A fastener, connected to the bottom of the housing, is provided with a fixing hole for fixing the heat transfer tube;

[0009] A downcomer is disposed outside the housing, and at least a portion of the downcomer extends axially along the housing; both ends of the downcomer are respectively connected to the flow channel;

[0010] The lower end cap is provided with a water inlet cavity and a water outlet cavity isolated from the water inlet cavity; the water inlet cavity is connected to the water inlet of the heat transfer tube, and the water outlet cavity is connected to the water outlet of the heat transfer tube.

[0011] In one embodiment, the downcomer is provided with a flow regulating valve.

[0012] In one embodiment, the downcomer includes a main downcomer pipe and two downcomer branches distributed in a horizontal direction, with a three-way valve connecting the main downcomer pipe and the two downcomer branches.

[0013] In one embodiment, the fixing hole includes a first hole segment and a second hole segment, wherein the diameter of the first hole segment is larger than the diameter of the heat transfer tube, and the diameter of the second hole segment is the same as the diameter of the heat transfer tube.

[0014] In one embodiment, a seal is provided within the first orifice.

[0015] In one embodiment, the inner wall of the heat transfer tube is coated with an anti-corrosion coating.

[0016] In one embodiment, the steam generator further includes a support member disposed within the housing, the support member having a support hole for connecting the heat transfer tube.

[0017] In one embodiment, the lower end cap is provided with a cavity, and an isolation member is provided in the cavity, the isolation member separating the cavity from the water inlet cavity and the water outlet cavity.

[0018] In one embodiment, the isolation member includes a first partition and a second partition, the first partition extending axially along the housing and connected to the fixing member;

[0019] The second partition is inclined relative to the first partition.

[0020] In one embodiment, the steam generator further includes a head cover connected to the lower head, the head cover being used to seal the cavity.

[0021] In one embodiment, the water inlet cavity includes multiple independent water inlet branch cavities, each of which is connected to multiple heat transfer pipes.

[0022] In one embodiment, the water inlet chamber is provided with a pressure detection point.

[0023] In one embodiment, the steam generator further includes a separation structure.

[0024] In one embodiment, the separation structure includes an upper conical segment and a lower conical segment, the upper conical segment and the lower conical segment having different tapers;

[0025] And / or, the inlet of the separation structure is provided with a flow guide.

[0026] In one embodiment, the steam generator further includes a drying structure.

[0027] In one embodiment, the surface of the drying structure is coated with a hydrophobic coating.

[0028] In one embodiment, the steam generator further includes a water inlet pipe that is connected to the water inlet cavity; the water inlet pipe is provided with at least one of a flow detection device, a pressure detection device, and a temperature detection device.

[0029] The steam generator also includes a water supply pipeline, which is connected to the flow channel; at least one of a flow detection device and a temperature detection device is provided on the water supply pipeline.

[0030] The top of the housing is provided with a steam outlet, and the steam outlet is provided with at least one of a flow detection element, a pressure detection element, and a humidity detection element.

[0031] A steam generator simulation structure includes a steam generator as described above.

[0032] Compared to existing methods that use annular gaps between the shell and cylinder to form a descending channel, the aforementioned steam generator and its simulated structure, by placing the downcomer outside the shell, avoids the annular gap occupying internal space, resulting in a more compact internal layout. The external downcomer can be directly bent and welded from standardized tubing, eliminating the need for custom-designed irregular structures to fit the annular gap, thus reducing manufacturing costs. In case of a malfunction, the external downcomer can be repaired or replaced directly without disassembling core components such as the shell and heat transfer tubes, reducing the risk of damage to core components during disassembly and lowering maintenance costs. Furthermore, descending channels using annular gaps require strict control of the coaxiality and gap uniformity between the shell and cylinder, necessitating multiple calibrations and adjustments; the external downcomer only requires fixing the two ends, simplifying the assembly process and shortening the test preparation cycle. Simultaneously, the diameter, length, and other parameters of the external downcomer can be flexibly adjusted without altering the main shell structure, facilitating comparative tests with different flow parameters, shortening the test cycle, and enabling more direct data monitoring during testing. This reduces test errors caused by structural complexity and lowers the cost of repeated testing. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments or exemplary embodiments of this application, the drawings used in the description of the embodiments or exemplary embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1This is a schematic diagram of a steam generator provided in one embodiment of this application.

[0035] Figure 2 for Figure 1 A partial schematic diagram of the steam generator is shown.

[0036] Figure 3 for Figure 1 A partial schematic diagram of the steam generator is shown.

[0037] Figure 4 for Figure 1 The steam generator shown is a side view.

[0038] Figure 5 for Figure 1 A schematic diagram of the drying structure in the steam generator is shown.

[0039] Reference numerals: 110, Shell; 111, Flow channel; 120, Heat transfer tube; 130, Fixing component; 140, Downcomer; 141, Flow regulating valve; 142, Downcomer main pipe; 143, Downcomer branch pipe; 144, Three-way valve; 150, Support component; 160, Lower end cap; 161, Inlet chamber; 162, Outlet chamber; 163, Isolation component; 170, End cap cover; 181, Separation structure; 182, Drying structure; 191, Water supply line; 192, Steam outlet; 210, Inlet line; 220, Outlet line. Detailed Implementation

[0040] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0041] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and 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.

[0042] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0043] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to 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 based on the specific circumstances.

[0044] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" 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. Similarly, "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.

[0045] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0046] As mentioned in the background section, steam generators, as crucial equipment in the industrial field, are widely used in numerous industries such as power, chemical, petroleum, and metallurgy. In nuclear power plants, steam generators play a central role, serving as a key link between the primary and secondary loops of the nuclear reactor. They are responsible for transferring the heat generated by the reactor core to the working fluid in the secondary loop, vaporizing it into steam, and ultimately driving the turbine generator to generate electricity. The stability and reliability of their operation directly affect the safe and economical operation of the nuclear power plant. The working principle of a steam generator is based on a heat exchange process. Taking a common pressurized water reactor nuclear power plant steam generator as an example, the high-temperature, high-pressure coolant from the reactor circulates in the primary loop and enters the heat transfer tubes of the steam generator, transferring heat to the water in the secondary loop through the tube walls. The secondary loop water absorbs heat, gradually heats up, and vaporizes, eventually forming high-temperature, high-pressure steam, which drives the turbine to rotate, thereby driving the generator to generate electricity. The operational stability of the steam generator has a significant impact on the safety, reliability, and economic benefits of the nuclear power plant, and the thermo-hydraulic performance of the steam generator is a key basis for ensuring the safe and stable operation of the equipment. Among related technologies, the testing cost of steam generators is relatively high.

[0047] Based on this, one embodiment of this application provides a steam generator that can reduce testing costs. The steam generator provided in one embodiment of this application will now be described in detail with reference to the accompanying drawings.

[0048] See Figures 1 to 4 As shown, a steam generator provided in one embodiment of this application includes a housing 110, a fixing member 130, a downcomer 140, and a lower end cap 160. The housing 110 has a flow channel 111 and a plurality of heat transfer tubes 120 inside. The fixing member 130 is connected to the bottom of the housing 110 and has fixing holes for fixing the heat transfer tubes 120. The downcomer 140 is disposed outside the housing 110, and at least a portion of the downcomer 140 extends along the axial direction of the housing 110. Both ends of the downcomer 140 are respectively connected to the flow channel 111. The lower end cap 160 is provided with a water inlet chamber 161 and a water outlet chamber 162 isolated from the water inlet chamber 161. The water inlet chamber 161 is connected to the water inlet of the heat transfer tubes 120, and the water outlet chamber 162 is connected to the water outlet of the heat transfer tubes 120.

[0049] The downcomer 140 provides a descending channel for the secondary loop water, allowing it to enter the flow channel 111 of the casing 110. The flow channel 111 includes an ascending channel. The secondary loop water entering the flow channel 111 absorbs heat from the primary loop coolant in the heat transfer tubes 120 and flows upward, absorbing heat transferred from the primary loop coolant during its ascent, thus completing the transformation from liquid water to a steam-water mixture. Multiple heat transfer tubes 120 inside the casing 110 can expand the heat exchange area, increase the heat transfer rate, and accelerate steam generation efficiency. The heat transfer tubes 120 are fixed by the fixing members 130 to prevent shaking during operation and reduce heat loss. The mutually isolated inlet chamber 161 and outlet chamber 162 provided by the lower end cap 160 isolate the hot and cold water, preventing mixing and ensuring continuous heat exchange.

[0050] Compared to the existing method of forming a descent channel through an annular gap between the shell 110 and the cylinder, placing the downcomer 140 outside the shell 110 avoids the annular gap occupying the internal space of the shell 110, resulting in a more compact internal layout. The external downcomer 140 can be directly bent and welded from standardized tubing, eliminating the need for custom-designed irregular structures to fit the annular gap, thus reducing manufacturing costs. In case of a malfunction, the external downcomer 140 can be repaired or replaced directly without disassembling core components such as the shell 110 and heat transfer tube 120, reducing the risk of damage to core components during disassembly and lowering maintenance costs. Furthermore, the annular gap descent channel requires strict control of the coaxiality and gap uniformity between the shell 110 and the cylinder, necessitating multiple calibrations and adjustments; the external downcomer 140 only requires fixing the two end interfaces, simplifying the assembly process and shortening the test preparation cycle. Meanwhile, the diameter, length and other parameters of the external downcomer 140 can be flexibly adjusted without modifying the main structure of the housing 110, which facilitates comparative tests of different flow parameters, shortens the test cycle, makes data monitoring during the test more direct, reduces test errors caused by structural complexity, and lowers the cost of repeated tests.

[0051] In some embodiments, the housing 110 can be made of metal, such as low-alloy steel. The fastener 130 can be a circular, thick-walled metal component, made of metal such as nickel-based alloy or low-alloy steel with nickel-based alloy overlay, and has multiple evenly distributed channels for fixing both ends of the heat transfer tube 120, while bearing the primary high pressure and thermal stress, possessing extremely high sealing performance and structural strength. In some embodiments, the heat transfer tube 120 can be a U-shaped tube, which has excellent corrosion resistance.

[0052] In some embodiments, the downcomer 140 can be made of metal, such as carbon steel, low alloy steel, stainless steel or heat-resistant alloy.

[0053] See Figure 1As shown, in one embodiment, the downcomer 140 is equipped with a flow regulating valve 141. By adjusting the opening of the flow regulating valve 141, the flow resistance can be adjusted, thereby changing the circulating flow rate and controlling the circulation ratio. This allows for the simulation of operating states under different flow rates and circulation ratios, simulating different working conditions. In some embodiments, the flow regulating valve 141 includes a valve body, a valve core, a valve stem, and a valve seat. The valve body serves as a fluid channel carrier, with an internal flow channel that mates with the valve core, adapting to the pipe diameter and pressure rating of the downcomer 140. The valve core can be spherical, needle-shaped, or sleeve-shaped. The valve core is driven by the valve stem, changing the gap with the valve seat to adjust the opening. The valve stem connects to the actuator, transmitting the regulating force. The valve seat and valve core are precisely fitted to form a sealing surface, controlling the flow on / off and the degree of throttling, ensuring regulating accuracy. The actuator can be manual, such as a handwheel, or electric, pneumatic, or hydraulic, depending on the experimental requirements. In some embodiments, sealing elements are provided at the valve stem and valve body, and at the valve core and valve seat, to prevent fluid leakage.

[0054] See Figures 1 to 4 As shown, in one embodiment, the downcomer 140 includes a main downcomer 142 and two horizontally distributed downcomer branches 143, with a three-way valve 144 connecting the main downcomer 142 and the two downcomer branches 143. The main downcomer 142 can be located above the downcomer branches 143 and can include a vertical pipe and an arc-shaped transition pipe. Similarly, the downcomer branches 143 can also include an arc-shaped transition pipe and a vertical pipe. The three-way valve 144 enables the switching of the main downcomer 142 and the two downcomer branches, as well as the flow distribution. The fluid flow ratio of the two downcomer branches can be adjusted as needed to adapt to different test conditions. When combined with the flow regulating valve 141, the three-way valve 144 can switch between single downcomer branch 143 or double downcomer branch 143 flow modes, expanding the flow regulation range and precisely matching the circulation ratio requirements. The three-way valve 144 directly switches the flow path without disassembling the pipeline, shortening the adjustment time and reducing the complexity of the test operation. Meanwhile, if a single downlink branch 143 fails, it can be quickly switched to another downlink branch 143 via a three-way valve 144 to ensure the continuity of the test.

[0055] In one embodiment, the fixing hole includes a first section and a second section. The diameter of the first section is larger than the diameter of the heat transfer tube 120; the diameter of the second section is the same as the diameter of the heat transfer tube 120. The larger diameter of the first section forms a guide inlet, allowing the heat transfer tube 120 to be quickly inserted without precise alignment during installation, reducing assembly difficulty and avoiding installation jams caused by a perfect match between the hole diameter and the tube diameter, thus shortening the disassembly and assembly time during equipment assembly or maintenance. The second section, with the same diameter as the heat transfer tube 120, achieves a tight fit, restricting radial sway of the heat transfer tube 120 and ensuring structural stability during operation. The tight fit of the second section also reduces the risk of fluid leakage from the gap outside the tube, improving the sealing effect and preventing any impact on fluid circulation efficiency. Moreover, the gap reserved in the first section can accommodate the thermal expansion and contraction of the heat transfer tube 120, avoiding damage to the tube body or cracking of the fastener 130 due to thermal deformation under high temperature conditions. The segmented structure does not affect the connection strength between the heat transfer tube 120 and the fastener 130, while reducing the extrusion damage to the surface of the heat transfer tube 120 and ensuring heat exchange efficiency.

[0056] In one embodiment, a seal is provided within the first orifice. The seal fills the gap between the orifice and the heat transfer tube 120, accommodates slight radial displacement of the heat transfer tube 120, prevents seal failure due to thermal expansion and contraction or vibration, ensures seal stability under high temperature and high pressure conditions, prevents fluid loss due to leakage, ensures stable flow into the heat transfer tube 120, and guarantees controllable heat exchange efficiency and circulation rate. Simultaneously, it prevents interference from fluid mixing in different flow channels, maintains separation of hot and cold water flows, and ensures the accuracy of experimental data. Furthermore, the seal buffers the assembly collision between the heat transfer tube 120 and the fixing hole, reducing damage to the tube surface, while also isolating the fixing member 130 from fluid erosion and corrosion, extending the component's service life. The seal can be made of copper alloy, flexible graphite, etc.

[0057] In one embodiment, the inner wall of the heat transfer tube 120 is coated with an anti-corrosion coating. This coating isolates the inner wall of the heat transfer tube 120 from direct contact with the fluid, preventing corrosion and scaling, reducing the risk of wall thinning and leakage due to corrosion, and extending the service life of the heat transfer tube 120. It also prevents the accumulation of corrosion products from affecting heat transfer performance, ensuring consistent heat exchange performance during testing and improving the reliability of test data. Furthermore, it reduces the frequency of replacement of the heat transfer tube 120 due to corrosion, lowering spare parts costs and equipment downtime for maintenance. The anti-corrosion coating can be a metallic coating, such as a stainless steel coating or a copper-based coating, or a ceramic coating, such as a chromium oxide coating or an aluminum oxide coating.

[0058] See Figures 1 to 4As shown, in one embodiment, the steam generator further includes a support member 150 disposed within the housing 110, the support member 150 having a support hole for connecting the heat transfer tube 120. Multiple support members 150 are provided, spaced apart along the axial direction of the housing 110. The support holes of the support members 150 provide multi-point positioning for the heat transfer tube 120, limiting its radial and axial movement, preventing deformation or breakage due to vibration under high temperature and pressure, and distributing the stress on the heat transfer tube 120, reducing the single-point bearing pressure on the fixing member 130, and lowering the overall structural fatigue risk. Simultaneously, it reduces the difficulty of disassembly and assembly during maintenance, extending the service life of the heat transfer tube 120 and the support member 150. In some embodiments, a limiting platform is welded to the inner wall of the housing 110, the edge of the support plate overlaps the limiting platform, and the limiting platform and the support member 150 are connected by fasteners such as bolts. In some embodiments, the edge of the support member 150 is directly welded to the inner wall of the housing 110 to form a rigid connection, which provides high structural strength, eliminates the risk of loosening, and is adaptable to the vibration and thermal shock during the operation of the steam generator. In some embodiments, the support member 150 can be a support plate.

[0059] See Figures 1 to 4 As shown, in one embodiment, the lower end cap 160 has a cavity, and an isolator 163 is disposed within the cavity. The isolator 163 separates the cavity into the inlet cavity 161 and the outlet cavity 162. The isolator 163 divides the cavity of the lower end cap 160 into the inlet cavity 161 and the outlet cavity 162, preventing the mixing of hot and cold water, avoiding interference, and ensuring heat exchange efficiency. The inlet cavity 161 centrally distributes hot water to the inlets of each heat transfer tube 120, and the outlet cavity 162 collects the low-temperature fluid from each heat transfer tube 120, forming a directional flow path and improving circulation efficiency. The isolator 163 forms a stable connection with the lower end cap 160, enhancing the overall structural rigidity of the lower end cap 160 and adapting to thermal expansion and contraction under high temperature and high pressure conditions.

[0060] See Figures 1 to 4 As shown, in one embodiment, the isolation member 163 includes a first partition and a second partition. The first partition extends axially along the housing 110 and is connected to the fixing member 130. The second partition is inclined relative to the first partition. The inclined arrangement of the second partition adapts to the flow trajectory of the high-temperature fluid, reduces eddies and flow resistance, and accelerates the convergence of the high-temperature fluid to the heat transfer tube 120. The first partition extends axially and is connected to the fixing member 130, guiding the hot water to be evenly distributed to the inlet of each heat transfer tube 120.

[0061] See Figures 1 to 4As shown, in one embodiment, the steam generator further includes a head cover 170 connected to the lower head 160, which is used to seal the cavity. The head cover 170 seals the cavity of the lower head 160, preventing leakage of high-temperature, high-pressure fluid, ensuring safe operation of the equipment, and maintaining stable pressure in the inlet chamber 161 and outlet chamber 162. The head cover 170 adopts a detachable design, such as bolted or flanged connections, facilitating the installation, maintenance, or replacement of the isolator 163 and heat transfer tube 120 interfaces. In some embodiments, the head cover 170 may be provided with a detection port to meet the needs of parameter monitoring and fluid sampling during the test process.

[0062] In one embodiment, the water inlet chamber 161 includes multiple independent water inlet branches, each of which is connected to multiple heat transfer tubes 120. Multiple heat transfer tubes 120 connected to a single water inlet branch constitute a group of heat transfer tubes 120. Each group of heat transfer tubes 120 can obtain a stable and balanced water flow rate, ensuring consistent heat exchange conditions for each heat transfer tube 120, thereby improving overall heat exchange efficiency and the reliability of experimental data. In some embodiments, branch regulating valves are provided in the water inlet branches. By independently controlling the flow rate of each water inlet branch, local load differences or fault conditions can be simulated, expanding the experimental scenarios.

[0063] In one embodiment, the water inlet branch is equipped with a pressure detection point. The pressure detection point directly collects real-time pressure data from each water inlet branch, intuitively reflecting the inlet pressure status of each group of heat transfer tubes 120. It promptly detects abnormal pressure fluctuations, quickly locates problems such as uneven flow distribution, blockage, or leakage, ensuring the accuracy of test data. Furthermore, it can record the pressure change patterns of each branch under different operating conditions, providing crucial data for optimizing flow channel design and verifying structural rationality. In addition, when a single water inlet branch or its corresponding heat transfer tube 120 malfunctions, the fault can be quickly located, reducing maintenance and troubleshooting difficulty and downtime.

[0064] See Figures 1 to 4 As shown, in one embodiment, the steam generator further includes a separation structure 181. In some embodiments, the separation structure 181 can be a cyclone separator, utilizing the principle of centrifugal force, where steam carrying water droplets enters the cyclone and rotates at high speed. The water droplets are thrown against the cylinder wall and collected before being discharged, while the steam is discharged from the central channel. In some embodiments, the separation structure 181 can be a corrugated plate separator, composed of multiple corrugated plates. When steam passes through the tortuous channels between the plates, water droplets impact the plate walls due to inertia, flow down the plate walls, and collect, while the steam continues to rise. In some embodiments, the separation structure 181 can be a wire mesh separator, which is a porous structure woven from metal wire mesh. When steam passes through, water droplets are trapped by the wire mesh and agglomerated into large droplets that fall, while the steam penetrates and separates.

[0065] In one embodiment, the separation structure 181 includes an upper conical section and a lower conical section, the upper and lower conical sections having different tapers. The lower conical section has a larger taper, which quickly guides the gas-liquid mixture to form a strong centrifugal force, efficiently separating large water droplets and improving separation efficiency. The upper conical section has a smaller taper, which reduces the steam flow rate, allowing small water droplets to settle or be trapped, improving steam dryness.

[0066] In one embodiment, the inlet of the separation structure 181 is provided with a flow guide. The flow guide can buffer the direct impact of the gas-liquid mixture on the inlet of the separation structure 181, avoid wall wear or corrosion caused by long-term scouring, and extend the service life of the separation structure 181. In some embodiments, the flow guide can be a flow guide vane or a spiral flow guide plate.

[0067] See Figures 1 to 4 As shown, see reference Figures 1 to 5 As shown, in one embodiment, the steam generator further includes a drying structure 182. In some embodiments, the drying structure 182 may be a corrugated plate dryer, a wire mesh dryer, a cyclone dryer, or a baffle plate dryer.

[0068] In one embodiment, the surface of the drying structure 182 is coated with a hydrophobic coating. The hydrophobic coating creates a low surface energy on the surface of the drying structure 182, preventing tiny water droplets from adhering and causing them to quickly aggregate into larger droplets that slide off the surface and drain away, further reducing the steam moisture content. Moreover, the smooth surface of the hydrophobic coating inhibits the adhesion of scale and impurities, preventing blockage of the flow channels or reduced drying efficiency due to scaling, and reducing the frequency of cleaning. In some embodiments, the hydrophobic coating can be a silica-based composite coating, an alumina-fluorine modified coating, etc.

[0069] See Figures 1 to 4As shown, in one embodiment, the steam generator further includes a water inlet pipe 210 for introducing primary loop water, such as high-temperature, high-pressure coolant from a nuclear reactor. The water inlet pipe 210 is connected to the water inlet cavity 161. A flow detection device is installed on the water inlet pipe 210. The flow detection device provides real-time feedback on the total water inlet volume to ensure that the water inlet meets the heat exchange requirements of the heat transfer tube 120. The flow detection device can be a flow sensor. In some embodiments, a pressure detection device is installed on the water inlet pipe 210 to detect the water inlet pressure, preventing overpressure damage to the pipe or cavity, or underpressure affecting fluid circulation. The pressure detection device can be a pressure sensor. In some embodiments, a temperature detection device is installed on the water inlet pipe 210 to capture changes in the water inlet temperature, providing basic data for heat exchange efficiency calculation and operating condition adjustment, and ensuring consistency of test conditions. The temperature detection device can be a temperature sensor. In some embodiments, the steam generator further includes a water outlet pipe 220, which may also be equipped with at least one of a flow detection element, a pressure detection element, and a temperature detection element.

[0070] See Figures 1 to 4 As shown, in one embodiment, the steam generator further includes a water supply pipe 191 for introducing secondary loop water, and the water supply pipe 191 is connected to the flow channel 111; a flow detection device is installed on the water supply pipe 191. The flow detection device provides real-time feedback on the secondary loop water supply, ensuring that the water supply meets the heat exchange requirements of the flow channel 111. In some embodiments, a temperature detection device is installed on the water supply pipe 191. The temperature detection device captures the water supply inlet temperature, providing key basic data for calculating the heat exchange efficiency between the secondary and primary loops and for heat balance analysis.

[0071] See Figures 1 to 4 As shown, in one embodiment, a steam outlet 192 is provided at the top of the housing 110. The steam outlet 192 is equipped with a flow detection device, which provides real-time feedback on the steam output to match the water supply and heat exchange requirements, preventing steam production imbalances from affecting the system's thermal balance. A pressure detection device is also provided at the steam outlet 192 to monitor the pressure, preventing overpressure from damaging pipelines and equipment, or insufficient pressure from affecting subsequent use. A humidity detection device is also provided at the steam outlet 192, directly reflecting the steam dryness and verifying the dehydration effect of the separation structure 181 and the drying structure 182, ensuring that the steam meets the requirements for cleanliness and low moisture content.

[0072] Furthermore, one embodiment of this application also provides a steam generator simulation structure, including the steam generator as described above. This simulation structure completely replicates the core modules of the steam generator, restoring the actual flow channels, heat exchange, and separation processes. It can achieve accurate simulation and data acquisition under different operating conditions, which is helpful for the study of the thermal-hydraulic performance of the steam generator.

[0073] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0074] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A steam generator, characterized in that, The steam generator includes: The shell (110) has a flow channel (111) and multiple heat transfer tubes (120) inside; A fastener (130) is connected to the bottom of the housing (110) and is provided with a fixing hole for fixing the heat transfer tube (120); A downcomer (140) is disposed outside the housing (110), and at least a portion of the downcomer (140) extends axially along the housing (110); both ends of the downcomer (140) are respectively connected to the flow channel (111); The lower end cap (160) is provided with a water inlet cavity (161) and a water outlet cavity (162) isolated from the water inlet cavity (161); the water inlet cavity (161) is connected to the water inlet of the heat transfer tube (120), and the water outlet cavity (162) is connected to the water outlet of the heat transfer tube (120).

2. The steam generator according to claim 1, characterized in that, The downcomer (140) is equipped with a flow regulating valve (141).

3. The steam generator according to claim 1, characterized in that, The downcomer (140) includes a downcomer main pipe (142) and two downcomer branches (143) distributed in the horizontal direction, and a three-way valve (144) is connected between the downcomer main pipe (142) and the two downcomer branches (143).

4. The steam generator according to claim 1, characterized in that, The fixing hole includes a first hole section and a second hole section. The diameter of the first hole section is larger than the diameter of the heat transfer tube (120). The diameter of the second hole section is the same as the diameter of the heat transfer tube (120).

5. The steam generator according to claim 4, characterized in that, A sealing element is provided inside the first hole section.

6. The steam generator according to claim 1, characterized in that, The inner wall of the heat transfer tube (120) is coated with an anti-corrosion coating.

7. The steam generator according to claim 1, characterized in that, The steam generator also includes a support member (150) disposed within the housing (110), the support member (150) having a support hole for connecting the heat transfer tube (120).

8. The steam generator according to claim 1, characterized in that, The lower end cap (160) has a cavity, and an isolation element (163) is provided in the cavity. The isolation element (163) separates the cavity into the water inlet cavity (161) and the water outlet cavity (162).

9. The steam generator according to claim 8, characterized in that, The isolation member (163) includes a first partition and a second partition, the first partition extending axially along the housing (110) and connected to the fixing member (130); The second partition is inclined relative to the first partition.

10. The steam generator according to claim 8, characterized in that, The steam generator also includes a head cover (170) connected to the lower head (160), the head cover (170) being used to seal the cavity.

11. The steam generator according to claim 1, characterized in that, The water inlet cavity (161) includes multiple independent water inlet branch cavities, each of which is connected to multiple heat transfer tubes (120).

12. The steam generator according to claim 11, characterized in that, The water inlet branch cavity is equipped with a pressure detection point.

13. The steam generator according to claim 1, characterized in that, The steam generator also includes a separation structure (181).

14. The steam generator according to claim 13, characterized in that, The separation structure (181) includes an upper conical segment and a lower conical segment, the upper conical segment and the lower conical segment having different tapers; And / or, the inlet of the separation structure (181) is provided with a flow guide.

15. The steam generator according to claim 1, characterized in that, The steam generator also includes a drying structure (182).

16. The steam generator according to claim 15, characterized in that, The surface of the drying structure (182) is coated with a hydrophobic coating.

17. The steam generator according to claim 1, characterized in that, The steam generator further includes a water inlet pipe (210), which is connected to the water inlet cavity (161); the water inlet pipe (210) is provided with at least one of a flow detection device, a pressure detection device, and a temperature detection device; The steam generator also includes a water supply pipe (191), which is connected to the flow channel (111); the water supply pipe (191) is provided with at least one of a flow detection element and a temperature detection element; The top of the housing (110) is provided with a steam outlet (192), and the steam outlet (192) is provided with at least one of a flow detection element, a pressure detection element, and a humidity detection element.

18. A steam generator simulation structure, characterized in that, Includes the steam generator as described in any one of claims 1 to 17.

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