A steam superheater

Abstract

This invention discloses a steam superheater, relating to the field of chemical waste heat recovery technology. It is used to reduce the temperature of the process gas at the inlet of the steam superheater and ensure the stability of the process gas temperature used for steam superheating, preventing the performance of the heat exchange tube material from deteriorating due to excessively high process gas temperatures, and simultaneously preventing fluctuations in the superheated steam temperature caused by fluctuations in process gas temperature. The steam superheater includes a waste heat boiler, a gas path regulating device, and a steam superheater body. The waste heat boiler is located at the inlet end of the steam superheater body along the flow direction of the process gas and includes a furnace drum, a central exhaust pipe, and a first heat exchange tube group. The central exhaust pipe and the first heat exchange tube group are located inside the furnace drum, with the first heat exchange tube group surrounding the central exhaust pipe. The gas path regulating device is located inside the furnace drum and includes a first valve, a second valve, and coaxially sleeved inner and outer cylinders. The inner cylinder is connected to the central exhaust pipe and is connected to the steam superheater body through the second valve.

Description

Technical Field

[0001] This invention relates to the field of waste heat recovery technology, and more specifically, to a steam superheater for recovering waste heat from a methanation reactor in a coal-to-natural gas process. Background Technology

[0002] In chemical processes such as the methanation of coal-to-natural gas and the conversion of synthetic ammonia, a large amount of waste heat is generated in the high-temperature process gas after the reaction. To improve energy efficiency, waste heat boilers are typically installed to recover this high-temperature sensible heat and produce steam as a byproduct. Simultaneously, to improve the steam quality and meet the needs of subsequent turbine operation or as a high-quality heat source, the waste heat in the process gas needs to be used to heat the saturated steam produced in the waste heat boiler into superheated steam via a steam superheater.

[0003] Considering economic factors, it is impractical to use expensive nickel-based alloys to manufacture the heat exchange tubes in steam superheaters. Under these economic constraints, the highest acceptable temperature-resistant material is T92, which, according to standards, has an upper limit of 649°C for permissible use and is generally used below 620°C. However, the temperature of the process gas often exceeds the safety threshold of the heat exchange tube material. If this high-temperature process gas directly enters the steam superheater and comes into contact with the heat exchange tubes, it will cause damage to the tubes. Traditional solutions typically involve installing independent cooling equipment at the front end of the steam superheater or introducing an external cold source for mixing and cooling. However, such solutions suffer from problems such as system complexity, large footprint, slow control response, or increased energy consumption.

[0004] Furthermore, since the operating conditions of the upstream reactor (such as load and catalyst activity) are not constant, the temperature of the process gas at its outlet will fluctuate accordingly. If the process gas temperature at the inlet of the steam superheater exceeds the safety threshold of the heat exchange tube material, the excessively high process gas temperature will cause the material properties of the heat exchange tube to deteriorate, resulting in poor equipment stability. Summary of the Invention

[0005] The purpose of this invention is to provide a steam superheater that addresses the problems in the prior art where the heat exchange tube material deteriorates due to excessively high and fluctuating inlet process temperatures, as well as the unstable quality of superheated steam. Simultaneously, it eliminates the need for complex external cooling systems, reducing floor space, energy consumption, and control response speed.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A steam superheater includes a waste heat boiler, a gas path regulating device, and a steam superheater body; the steam superheater body is used for secondary heat exchange of process gas.

[0008] The waste heat boiler is located at the inlet end of the main body of the steam superheater along the flow direction of the process gas. The waste heat boiler includes a furnace drum, a central exhaust pipe and a first heat exchange tube group. The central exhaust pipe and the first heat exchange tube group are located inside the furnace drum. The central exhaust pipe is used to pass through the unheated process gas, and the first heat exchange tube group is arranged around the central exhaust pipe to perform primary heat exchange on the process gas.

[0009] The gas path regulating device is installed inside the furnace drum. The gas path regulating device includes a first valve, a second valve, and an inner cylinder and an outer cylinder coaxially sleeved together. An annular cavity is formed between the inner cylinder and the outer cylinder. The annular cavity is connected to the first heat exchange tube group for the passage of process gas after one heat exchange. The inner cylinder is connected to the central exhaust pipe for the passage of process gas that has not undergone heat exchange. The first valve is installed on the outer cylinder for controlling the opening and closing of the annular cavity and the main body of the steam superheater. The second valve is installed on the inner cylinder for controlling the opening and closing of the inner cylinder and the main body of the steam superheater.

[0010] Optionally, in the above-mentioned steam superheater, the ends of the outer cylinder and the inner cylinder away from the first heat exchange tube group are both closed, the outer circumferential surface of the outer cylinder is provided with a first opening, and the first valve is moved radially along the outer cylinder and disposed in the first opening to control the degree of opening and closing of the first opening.

[0011] The inner cylinder extends from the outer cylinder at the end away from the first heat exchange tube assembly to form an extension. A second opening is provided on the outer circumferential surface of the extension. A second valve is installed in the second opening and moves radially along the inner cylinder to control the opening and closing degree of the second opening.

[0012] Optionally, in the above-mentioned steam superheater, the first opening has two axial edges parallel to the axial direction of the outer cylinder and two parallel circumferential edges extending along the circumference of the outer cylinder, the two axial edges and the two circumferential edges forming the first opening.

[0013] The first valve includes a first side plate, a top plate, and a second side plate connected in sequence. The first side plate and the second side plate are arranged in parallel. The bottom surfaces of the first side plate and the second side plate respectively contact and seal with two axial edges. The two end sides of the first side plate, the second side plate, and the top plate are respectively used to contact and seal with two circumferential edges.

[0014] Optionally, in the above-mentioned steam superheater, two first flanges are also provided on the outer cylinder, and the first flanges protrude radially along the outer cylinder;

[0015] The sidewalls of the first side plate and the second side plate are also provided with cantilever arms. The cantilever arms include a first part and a second part that are perpendicular to each other. The first part is perpendicular to the sidewalls of the first side plate and the second side plate. The second part is fixed to the end of the first part away from the sidewall and extends downward. The bottom surface of the first part is used to contact and seal with the top surface of the first flange. The side of the second part near the first part is used to contact and seal with the side of the first flange.

[0016] Optionally, in the above-mentioned steam superheater, two second flanges are also provided on the outer cylinder. The second flanges protrude radially along the outer cylinder, and the bottom surface of the top plate is used to contact and seal with the top surface of the second flanges.

[0017] Optionally, in the above-mentioned steam superheater, the second flange is provided with a baffle extending along the axial direction of the outer cylinder and toward the first opening, and a cantilever is located between the baffle and the first flange. The baffle is positioned at the upper limit of the cantilever in the radial direction parallel to the outer cylinder to limit the maximum opening position of the first valve relative to the outer cylinder.

[0018] Optionally, in the above-described steam superheater, the main body of the steam superheater includes:

[0019] The superheater tube shell is fixedly connected to the furnace drum. A heat exchange chamber and a steam chamber are arranged sequentially along its axial direction in the superheater tube shell. A steam inlet, a steam outlet and a process gas outlet are opened on the superheater tube shell. The steam inlet is connected to the steam chamber and is used to introduce saturated steam. The steam outlet is used to output superheated steam. The process gas outlet is connected to the heat exchange chamber and is used to output process gas after secondary heat exchange.

[0020] The inner shell is fixedly installed inside the heat exchange chamber. The two ends of the inner shell are open and have a first end and a second end opposite to each other along the axial direction of the superheater tube shell. The first end of the inner shell is connected to the gas path regulating device and is sealed to the inner wall of the superheater tube shell. An annular first gap is formed between the inner shell and the superheater tube shell. The second end of the inner shell is connected to the first gap. The first gap is used for the process gas after secondary heat exchange.

[0021] The tube sheet is fixedly connected to the superheater tube shell and is sealed between the heat exchange chamber and the steam chamber. The tube sheet is provided with heat exchange tube mounting holes.

[0022] The second heat exchange tube group is located inside the inner shell. The heat exchange tubes in the second heat exchange tube group have an inlet end and an outlet end. The heat exchange tubes in the second heat exchange tube group are used to introduce steam. The inlet end is connected to the steam chamber, and the outlet end is connected to the steam outlet. All heat exchange tubes in the second heat exchange tube group are sealed and installed in the heat exchange tube mounting hole.

[0023] The third valve is located on the inner shell. The opening and closing of the third valve controls the flow between the inner shell and the first gap. Along the flow direction of the process gas, the third valve is located upstream of the second heat exchange tube group.

[0024] Optionally, in the above-mentioned steam superheater, the main body of the steam superheater also includes a buffer cover, which is fixedly connected to the inner shell. A cavity is formed between the buffer cover and the outer wall of the inner shell. The third valve is located in the cavity. The buffer cover has multiple openings, and the cavity and the first gap are connected through the openings.

[0025] Optionally, in the aforementioned steam superheater, the inner shell is provided with a plurality of alternating and spaced first baffles and second baffles. The outer edge of the first baffle is sealed and fixed to the inner wall of the inner shell. The first baffle has a first through hole, and the second baffle has a second through hole. The heat exchange tubes in the second heat exchange tube group pass through the first through hole and the second through hole. There is an annular gap between the hole wall of the second through hole and the heat exchange tube. The annular gap is used for the passage of process gas. The first baffle has a plurality of first through holes, and the second baffle has a plurality of second through holes. The diameter of the first through hole is smaller than the diameter of the second through hole. The first through hole and the second through hole are used for the passage of process gas.

[0026] Optionally, in the above-mentioned steam superheater, the heat exchange tubes in the second heat exchange tube group include an inner tube and an outer tube. The outer tube is coaxially sleeved outside the inner tube, and a second gap is formed between the outer tube and the inner tube. The outer tube has a closed end and a steam inlet end that are arranged opposite to each other. A protective cover is fixedly installed on the outside of the closed end. The protective cover has two ends fixed on the outside of the closed end, and the protective cover and the outer tube form a closed cavity. The closed end is located inside the closed cavity. The steam inlet end has a through hole that connects the steam cavity and the second gap. The inner tube includes two intersecting ends, and one end is connected to the steam outlet.

[0027] Compared with the prior art, the steam superheater provided in this application includes a waste heat boiler, a gas path regulating device, and a steam superheater body. The steam superheater body is used for secondary heat exchange of process gas. The waste heat boiler is located at the inlet end of the steam superheater body along the flow direction of the process gas. The waste heat boiler includes a furnace shell, a central exhaust pipe, and a first heat exchange tube group. The central exhaust pipe and the first heat exchange tube group are located inside the furnace shell. The inlet of the central exhaust pipe is used to introduce unexchanged process gas. The first heat exchange tube group is arranged around the central exhaust pipe and is used to heat the process gas. A single heat exchange is performed. A gas path regulating device is installed inside the furnace drum. This device includes a first valve, a second valve, and coaxially fitted inner and outer cylinders. An annular cavity is formed between the inner and outer cylinders, communicating with the first heat exchange tube group for introducing the process gas after the first heat exchange. The inner cylinder is connected to the central exhaust pipe for introducing the process gas that has not yet undergone heat exchange. The first valve is located on the outer cylinder and controls the opening and closing of the annular cavity and the main body of the steam superheater. The second valve is located on the inner cylinder and controls the opening and closing of the inner cylinder and the main body of the steam superheater. For specific implementation details, please refer to [link / reference needed]. Figure 1In the steam superheater provided by this invention, a waste heat boiler is located at the front end of the process gas inlet of the main body of the steam superheater. The central exhaust pipe inside the furnace of the waste heat boiler introduces unexchanged process gas, and the process gas after one heat exchange passes through the first heat exchange tube group arranged around the outside of the central exhaust pipe. The gas path regulating device is arranged inside the furnace and forms a physically isolated dual airflow channel through the coaxially sleeved inner and outer cylinders. The inner cylinder is connected to the central exhaust pipe to transport unexchanged process gas into the main body of the steam superheater, and the annular cavity is connected to the first heat exchange tube group to transport the lower-temperature high-temperature process gas after one heat exchange into the main body of the steam superheater. The annular cavity and the inner cylinder are respectively connected to the main body of the steam superheater through independently controlled first and second valves. During operation: When it is necessary to reduce the temperature of the process gas entering the main body of the steam superheater, the first valve and the second valve can be opened simultaneously. The process gas that has not undergone heat exchange (i.e., the process gas that has not been cooled) flows out from the inner cylinder, while the process gas that has undergone heat exchange once (i.e., the process gas that has been cooled after heat exchange in the first heat exchange tube group) flows out from the annular cavity. The two streams of gas mix before entering the main body of the steam superheater. The ratio of the two streams of gas is controlled by adjusting the opening of the first valve and the second valve respectively, so as to achieve precise temperature regulation. Alternatively, when it is necessary to reduce the temperature of the process gas entering the main body of the steam superheater, only the first valve is opened. At this time, the process gas that has undergone heat exchange and cooling at the first heat exchange tube group (i.e., the process gas that has undergone heat exchange once) enters the main body of the steam superheater from the annular cavity, thereby reducing the temperature of the process gas entering the main body of the steam superheater. This configuration allows the built-in gas flow regulating device to precisely mix the unheated process gas with the lower-temperature process gas cooled by the first heat exchange tube group. By coordinating the opening of the first and second valves, the temperature of the process gas finally entering the main body of the steam superheater can be precisely controlled below the preset safety threshold. This solves the risk of overheating of the heat exchange tubes caused by excessively high absolute temperature of the inlet process gas, thus improving the operational safety of the equipment. Furthermore, by adjusting the first and second valves, the ratio of the flow rate of the unheated process gas and the process gas after one heat exchange can be quickly adjusted, accelerating the control response speed and effectively offsetting disturbances in the inlet temperature. This maintains a constant temperature of the process gas entering the main body of the steam superheater, ultimately ensuring a stable temperature of the produced superheated steam and meeting the downstream demand for high-quality and stable steam. Integrating the cooling and temperature control functions into the furnace drum of the waste heat boiler eliminates the need for external independent cooling equipment or cold sources. The compact structure reduces the footprint and avoids the additional energy consumption caused by introducing external cold sources, conforming to the design concept of energy conservation and consumption reduction. Attached Figure Description

[0028] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0029] Figure 1This is a schematic diagram of the overall structure of a steam superheater provided in an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of the structure of a steam superheater gas path regulating device with the first valve in a closed state, provided in an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the structure of a steam superheater gas path regulating device with the first valve in the open state, provided in an embodiment of the present invention;

[0032] Figure 4 This is an enlarged schematic diagram of the gas path regulating device of a steam superheater provided in an embodiment of the present invention;

[0033] Figure 5 This is an enlarged schematic diagram of the main body of a steam superheater provided in an embodiment of the present invention;

[0034] Figure 6 This is an enlarged schematic diagram of the third valve of a steam superheater provided in an embodiment of the present invention;

[0035] Figure 7 This is a schematic diagram of the structure of the first baffle plate of a steam superheater provided in an embodiment of the present invention;

[0036] Figure 8 This is a schematic diagram of the structure of the second baffle plate of a steam superheater provided in an embodiment of the present invention;

[0037] Figure 9 This is a schematic diagram of the overall structure of the heat exchange tubes in the second heat exchange tube group of a steam superheater provided in an embodiment of the present invention.

[0038] Figure 10 This is a partially enlarged schematic diagram of the heat exchange tubes in the second heat exchange tube group of a steam superheater provided in an embodiment of the present invention.

[0039] Reference numerals: 100 waste heat boiler, 110 furnace drum, 120 central exhaust pipe, 130 first heat exchange tube assembly, 200 gas path regulating device, 210 inner cylinder, 2101 extension, 220 outer cylinder, 230 first valve, 231 first side plate, 232 top plate, 233 second side plate, 240 second valve, 222 first flange, 223 second flange, 2231 baffle, 234 cantilever, 300 steam superheater body, 310 superheater tube shell, 311 heat exchange chamber, 312 steam chamber, 31 3 is the steam inlet, 314 is the steam outlet, 315 is the process gas outlet, 320 is the inner shell, 330 is the first gap, 340 is the tube sheet, 350 is the second heat exchange tube assembly, 360 is the third valve, 370 is the buffer cover, 3701 is the opening, 380 is the first baffle, 3801 is the first through hole, 3802 is the first through hole, 390 is the second baffle, 3901 is the second through hole, 400 is the heat exchange tube, 410 is the fin, 420 is the protective cover, 430 is the inner sleeve, 440 is the outer sleeve, 450 is the second gap, and 460 is the closed end. Detailed Implementation

[0040] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0041] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0043] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0044] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] like Figure 1 As shown, the steam superheater provided in this embodiment of the invention includes a waste heat boiler 100, a gas path regulating device 200, and a steam superheater body 300. The steam superheater body 300 is used for secondary heat exchange of process gas. The waste heat boiler 100 is disposed at the inlet end of the steam superheater body 300 along the flow direction of the process gas. The waste heat boiler 100 includes a furnace drum 110, a central exhaust pipe 120, and a first heat exchange tube group 130. The central exhaust pipe 120 and the first heat exchange tube group 130 are disposed within the furnace drum 110. The inlet of the central exhaust pipe 120 is used to introduce unexchanged process gas. The first heat exchange tube group 130 is arranged around the central exhaust pipe 120 for primary heat exchange of the process gas. The gas path regulating device 200... The regulating device 200 is installed inside the furnace cylinder 110. The gas path regulating device 200 includes a first valve 230, a second valve 240, and an inner cylinder 210 and an outer cylinder 220 coaxially sleeved together. An annular cavity is formed between the inner cylinder 210 and the outer cylinder 220. The annular cavity is connected to the first heat exchange tube group 130 for introducing process gas after one heat exchange. The inner cylinder 210 is connected to the central exhaust pipe 120 for introducing process gas that has not been heat exchanged. The first valve 230 is installed on the outer cylinder 220 for controlling the opening and closing of the annular cavity and the steam superheater body 300. The second valve 240 is installed on the inner cylinder 210 for controlling the opening and closing of the inner cylinder 210 and the steam superheater body 300.

[0046] For specific implementation details, please refer to [link / reference]. Figure 1 and Figure 4In the steam superheater provided by the present invention, a waste heat boiler 100 is located at the front end of the process gas inlet of the steam superheater body 300. The central exhaust pipe 120 inside the furnace shell 110 of the waste heat boiler 100 introduces unexchanged process gas, and the process gas after one heat exchange passes through the first heat exchange tube group 130 arranged around the outside of the central exhaust pipe 120. The gas path regulating device 200 is arranged inside the furnace shell 110 and forms a physically isolated dual airflow channel through the coaxially sleeved inner cylinder 210 and outer cylinder 220. The inner cylinder 210 is connected to the central exhaust pipe 120 to deliver unexchanged process gas into the steam superheater body 300, and the annular cavity is connected to the first heat exchange tube group 130 to deliver the lower temperature process gas after one heat exchange into the steam superheater body 300. The annular cavity and the inner cylinder 210 are respectively connected to the steam superheater body 300 through independently controlled first valve 230 and second valve 240. During operation: When it is necessary to reduce the temperature of the process gas input to the main body 300 of the steam superheater, the first valve 230 and the second valve 240 can be opened simultaneously. The process gas that has not been heat-exchanged (i.e., the process gas that has not been cooled) flows out from the inner cylinder 210, and the process gas that has undergone one heat exchange (i.e., the process gas that has been cooled by heat exchange in the first heat exchange tube group 130) flows out from the annular cavity. The two streams of gas mix before entering the main body 300 of the steam superheater. The ratio of the two streams of gas is controlled by adjusting the opening of the first valve 230 and the second valve 240 respectively, so as to achieve precise temperature regulation. Alternatively, when it is necessary to reduce the temperature of the process gas input to the main body 300 of the steam superheater, only the first valve 230 is opened. At this time, the process gas that has undergone heat exchange and cooling in the first heat exchange tube group 130 (i.e., the process gas that has undergone one heat exchange) enters the main body 300 of the steam superheater from the annular cavity, thereby reducing the temperature of the process gas entering the main body 300 of the steam superheater. With this configuration, by adjusting the opening and closing relationship and degree of opening and closing of the first valve 230 and the second valve 240 on the gas path regulating device 200, the temperature of the process gas entering the steam superheater body 300 and reaching the heat exchange tube 400 in the steam superheater body 300 can be flexibly adjusted, so that the temperature of the process gas can be reduced to a preset safe temperature, ensuring the thermal performance of the heat exchange tube 400 material and improving the stability of the equipment; at the same time, the temperature of the process gas can be adjusted only by controlling the first valve 230 and the second valve 240, which speeds up the control response speed; through the built-in gas path regulating device 200, there is no need to introduce an external complex cooling equipment system, reducing the footprint and energy consumption.

[0047] Understandably, if the process gas entering the main body 300 of the steam superheater does not need to be cooled, the process gas can directly enter the main body 300 of the steam superheater by adjusting the gas path regulating device 200, closing the first valve 230 and opening only the second valve 240.

[0048] It should be noted that the "process gas after one heat exchange" mentioned above refers to the process gas after heat exchange at the first heat exchange tube group 130. The process gas flowing at the first heat exchange tube group 130 exchanges heat with the cooling medium outside the first heat exchange tube group 130, and the temperature of the process gas decreases, so that a temperature difference is formed between the process gas in the first heat exchange tube group 130 and the process gas in the central exhaust pipe 120.

[0049] As one possible implementation, such as Figure 2 and Figure 3 As shown, the outer cylinder 220 and the inner cylinder 210 are both closed at the ends away from the first heat exchange tube assembly 130. The outer circumferential surface of the outer cylinder 220 has a first opening. The first valve 230 is moved radially along the outer cylinder 220 and is disposed in the first opening to control the opening degree of the first opening. The end of the inner cylinder 210 away from the first heat exchange tube assembly 130 extends out of the outer cylinder 220 and forms an extension 2101. The outer circumferential surface of the extension 2101 has a second opening. The second valve 240 is moved radially along the inner cylinder 210 and is disposed in the second opening to control the opening degree of the second opening.

[0050] Specifically, the gas path regulating device 200 is installed inside the furnace cylinder 110 of the waste heat boiler 100. The ends of the outer cylinder 220 and the inner cylinder 210 away from the first heat exchange tube group 130 are both closed structures. A first opening is opened on the outer peripheral surface of the outer cylinder 220. A first valve 230 is installed in the first opening and moves radially along the outer cylinder 220. The opening degree of the first opening is adjusted by adjusting the radial displacement of the first valve 230 relative to the outer cylinder 220. One end of the inner cylinder 210 extends out of the closed end of the outer cylinder 220 to form an extension 2101. The closed end of the outer cylinder 220 is sealed and joined to the outer peripheral surface of the extension 2101 of the inner cylinder 210. A second opening is opened on the outer peripheral surface of the extension 2101. A second valve 240 is installed in the second opening and moves radially along the inner cylinder 210. The opening degree of the second opening is adjusted by adjusting the radial displacement of the second valve 240 relative to the inner cylinder 210. During operation: By radially moving the first valve 230 and the second valve 240, the flow ratio of the unheated process gas in the inner cylinder 210 and the lower-temperature process gas after primary heat exchange in the annular cavity are controlled respectively. When it is necessary to reduce the temperature of the process gas flowing into the steam superheater body 300, the first valve 230 and the second valve 240 can be opened simultaneously and the opening ratio adjusted, so that the unheated process gas flows out from the second opening and the lower-temperature process gas after primary heat exchange flows out from the first opening, allowing the two airflows to flow as needed. The process gas is either mixed, or the first valve 230 is opened while the second valve 240 is closed, allowing the lower-temperature process gas after the first heat exchange in the annular cavity to flow out from the first opening and into the steam superheater body 300. At this time, the process gas in the inner cylinder 210 that has not undergone heat exchange will not flow into the steam superheater body 300 due to the closure of the second valve 240. When cooling is not required, the first valve 230 is closed, and the process gas that has not undergone heat exchange and cooling flows directly into the steam superheater body 300 through the open second valve 240. With this configuration, the first valve 230 is located at the first opening of the outer cylinder 220, and the second valve 240 is located at the second opening of the inner cylinder 210. When adjusting the temperature of the process gas flowing into the steam superheater body 300, the temperature can be adjusted simply by moving the first valve 230 or the second valve 240 radially along the outer cylinder 220 or the inner cylinder 210, which is convenient and quick.

[0051] In some embodiments, the furnace drum 110 of the waste heat boiler 100 has two passage openings at positions corresponding to the first valve 230 and the second valve 240, for connecting externally to the drive mechanism of the first valve 230 and the second valve 240. The drive mechanism can drive the first valve 230 and the second valve 240 to move radially along the furnace drum 110. The drive mechanism extends out of the furnace drum 110 of the waste heat boiler 100 through these two passage openings to form operating ends for operating the first valve 230 and the second valve 240. The drive mechanism is sealed to the furnace drum 110 of the waste heat boiler 100 at the passage openings. In practical implementation, the operating ends of the first valve 230 and the second valve 240 can be directly operated from outside the furnace cylinder 110 by lifting or pressing the drive mechanism. This controls the radial movement of the first valve 230 along the outer cylinder 220 or the radial movement of the second valve 240 along the inner cylinder 210. Lifting the first valve 230 increases the opening of the first valve 230 and the second valve 240, while pressing it down decreases their opening. When it is necessary to lower the process gas temperature, the first valve 230 and the second valve 240 are simultaneously lifted, and the height difference is adjusted to increase the proportion of lower-temperature process gas. When cooling is not required, the first valve 230 is pressed down to close, leaving only the passage of the second valve 240 open, allowing the unexchanged process gas to flow directly through the inner cylinder 210 from the second opening and into the steam superheater body 300. With this configuration, the opening of the first valve 230 and the second valve 240 can be adjusted simply by lifting or pressing the drive mechanism from outside the furnace cylinder 110, making it convenient to adjust the process gas temperature. In some embodiments, the drive mechanism includes a pneumatic drive mechanism.

[0052] In some embodiments, such as Figure 2 and Figure 3 As shown, the second valve 240 is a plunger valve. A cylindrical structure is provided on the outer circumferential surface of the extension 2101 of the inner cylinder 210. The axial direction of the cylindrical structure is perpendicular to the axial direction of the inner cylinder 210, and the cylindrical structure is connected to the inner cylinder 210. The plunger valve is located inside the cylindrical structure. By lifting or pressing down the plunger valve, the opening degree of the plunger valve is adjusted to change the flow rate of the process gas that has not undergone heat exchange and cooling, thereby adjusting the flow ratio of the mixed process gas and thus regulating the temperature of the process gas introduced into the steam superheater body 300.

[0053] As one possible implementation, such as Figure 2 and Figure 3As shown, the first opening has two axial edges parallel to the axial direction of the outer cylinder 220, and two parallel circumferential edges extending circumferentially along the outer cylinder 220. The two axial edges and the two circumferential edges form the first opening. The first valve 230 includes a first side plate 231, a top plate 232, and a second side plate 233 connected in sequence. The first side plate 231 and the second side plate 233 are arranged in parallel. The first side plate 231 and the second side plate 233 have bottom surfaces that can respectively contact and seal with the two axial edges. The two end sides of the first side plate 231, the second side plate 233, and the top plate 232 are respectively used to contact and seal with the two circumferential edges.

[0054] Specifically, the second opening in the outer cylinder 220 of the steam superheater gas path regulating device 200 has two axial edges parallel to the cylinder axis and two parallel circumferential edges extending circumferentially along the outer cylinder 220; the first valve 230 is radially moved to cooperate with the first opening, and its structure includes a first side plate 231, a second side plate 233 and a top plate 232 connected to each other. The first side plate 231 and the second side plate 233 are arranged in parallel, and their bottom surfaces respectively contact and seal with the two axial edges, while the bottom surface of the top plate 232 contacts and seals with the two circumferential edges. During operation: When it is necessary to adjust the flow rate of the lower-temperature process gas after the first heat exchange, the first valve 230 is pulled radially along the outer cylinder 220, disconnecting the contact between the bottom surface of the first side plate 231 and the second side plate 233 and the axial edge. Simultaneously, the contact between the bottom surface of the top plate 232 and the circumferential edge is also disconnected. At this time, the lower-temperature process gas after the first heat exchange, located in the annular cavity, flows out of the annular cavity through the gap between the circumferential edge and the bottom surface of the top plate 232, and also flows out of the annular cavity through the gap between the axial edge and the bottom surfaces of the first side plate 231 and the second side plate 233. The flow rate of the process gas after the first heat exchange is determined by the degree of opening and closing of the first valve 230, thereby adjusting the mixing ratio with the process gas that has not undergone heat exchange, and thus controlling the temperature of the mixed process gas. When it is not necessary to lower the temperature of the process gas introduced into the steam superheater body 300, the flow rate can be adjusted along the outer cylinder 220. Pressing the first valve 230 radially downwards causes the bottom surfaces of the first side plate 231 and the second side plate 233 to contact and seal against the axial edge of the outer cylinder 220, and the bottom surface of the top plate 232 to contact and seal against the circumferential edge of the outer cylinder 220. At this time, the process gas in the annular cavity, after being cooled by heat exchange once, is sealed in the annular cavity and cannot flow into the steam superheater body 300. Opening the second valve 240 allows the process gas that has not undergone heat exchange to directly enter the steam superheater body 300. The two ends of the first side plate 231, the second side plate 233, and the top plate 232 have contact surfaces that contact and seal against the two circumferential edges. When the first valve 230 is closed and sealed with the first opening, the contact surfaces of the two ends of the first side plate 231, the second side plate 233, and the top plate 232 are in contact with the planes of the two circumferential edges facing the first opening, further increasing the sealing effect. This design, through a three-sided planar sealing design, enhances the sealing effect of the first valve 230, ensures the sealing of the annular cavity, reduces the possibility of accidental leakage of process gas within the annular cavity, and improves the accuracy of process gas temperature adjustment. Simultaneously, the design of the first valve 230, including a first side plate 231, a second side plate 233, and a top plate 232, allows process gas to flow out of the annular cavity through the gap between the circumferential edge and the bottom surface of the top plate 232, and through the gap between the axial edge and the bottom surfaces of the first and second side plates 231 and 233, increasing the gas flow rate and improving temperature regulation efficiency.

[0055] Furthermore, such as Figure 2 and Figure 3 As shown, the outer cylinder 220 is also provided with two first flanges 222. The two first flanges 222 protrude radially along the outer cylinder 220. The side walls of the first side plate 231 and the second side plate 233 are also provided with cantilever 234. The cantilever 234 includes a first part and a second part that are perpendicular to each other. The first part is perpendicular to the side walls of the first side plate 231 and the second side plate 233. The second part is fixed to the end of the first part away from the side wall and extends downward. The bottom surface of the first part is used to contact and seal with the top surface of the first flange 222. The side of the second part near the first part is used to contact and seal with the side of the first flange 222.

[0056] In practice, when it is necessary to adjust the flow rate of the process gas exiting from the first valve 230, the first valve 230 is pulled upwards, moving away from the outer cylinder 220. At this time, the contact between the bottom surface of the first part of the cantilever 234 and the top surface of the first flange 222 is broken, and the contact between the side surface of the second part of the cantilever 234 and the side surface of the first flange 222 is broken, allowing the process gas after one heat exchange to flow out from the annular cavity. When it is necessary to close the first valve 230, the first valve 230 is pushed downwards, moving closer to the outer cylinder 220 until the bottom surface of the first part of the cantilever 234 is in contact with the top surface of the first flange 222. The top surface of the flange 222 is in sealing contact. At this time, the side of the second part of the cantilever 234 is in close contact with the side of the first flange 222, forming a double-layer sealing surface. This blocks the leakage path of the process gas in the annular cavity along the axial edge, enhances the sealing effect, and thus improves the accuracy of controlling the temperature of the process gas. At the same time, it can also limit the relative displacement between the first valve 230 and the outer cylinder 220 (this relative displacement is the displacement along the radial direction of the outer cylinder 220, and can be understood as the radial displacement in the left and right direction). The side of the second part is in contact with the side of the first flange 222, which can also effectively counteract the instability of the first valve 230 caused by the airflow impact.

[0057] Furthermore, such as Figure 2 and Figure 3 As shown, the outer cylinder 220 is also provided with two second flanges 223. The two second flanges 223 protrude radially along the outer cylinder 220, and the bottom surface of the top plate 232 is used to contact and seal with the top surface of the second flanges 223.

[0058] In practice, when the first valve 230 blocks the first opening on the outer cylinder 220, the bottom surface of the top plate 232 contacts and seals with the top surface of the second flange 223. When the first valve 230 is pulled upward, the contact between the bottom surface of the top plate 232 and the top surface of the second flange 223 is broken, and the process gas after the first heat exchange in the annular cavity flows out through this broken gap. The contact and sealing between the bottom surface of the top plate 232 and the top surface of the second flange 223, along with the design of the second flange 223 protruding from the outer cylinder 220, provides a certain degree of support for the first valve 230, increasing the sealing effect.

[0059] In some embodiments, the shape of the bottom surface of the top plate 232 matches and fits the shape of the top surface of the second flange 223. That is, if the top plate 232 is an arc-shaped plate with an arc-shaped bottom surface, then the top surface of the second flange 223 is an arc-shaped surface. The shape matching further improves the sealing effect and enhances the stability during sealing contact. If the top plate 232 is a flat plate with a flat bottom surface, then the top surface of the second flange 223 is a flat surface. The two can be matched.

[0060] Furthermore, such as Figure 2 and Figure 3 As shown, the second flange 223 is provided with a baffle 2231 extending along the axial direction of the outer cylinder 220 and toward the first opening. The cantilever 234 is located between the baffle 2231 and the first flange 222. The baffle 2231 is positioned at the upper limit of the cantilever 234 in the radial direction parallel to the outer cylinder 220 to limit the maximum opening position of the first valve 230 relative to the outer cylinder 220.

[0061] Specifically, the outer cylinder 220 is provided with two parallel second flanges 223. Four baffles 2231 are fixedly installed on the opposite surfaces of the two second flanges 223, corresponding to the corners of the second flanges 223. The two opposing baffles 2231 extend relative to each other along the axial direction of the outer cylinder 220. When the first valve 230 is pulled to its highest position, the top surface of the first part of the cantilever 234, located on the sidewalls of the first side plate 231 and the second side plate 233 of the first valve 230, contacts the bottom surface of the baffle 2231. At this time, the opening of the first valve 230 reaches its maximum. When the first valve 230 is pressed down, the bottom surface of the first part of the cantilever 234 contacts the top surface of the first flange 222. At this time, the opening of the first valve 230 reaches its minimum, and the annular cavity is sealed. This configuration ensures that when adjusting the opening of the first valve 230, the maximum lifting displacement distance of the first valve 230 is limited by the baffle 2231, ensuring that the first valve 230 will not come out of the first opening of the outer cylinder 220, thus maintaining the stability of the device.

[0062] In some embodiments, the baffle 2231 slides in contact with the side surface of the first side plate 231 or the second side plate 233. The fixedly installed baffle 2231 plays a guiding role when the first valve 230 moves, so as to avoid the possible displacement of the first valve 230 in the direction perpendicular to the axial direction of the outer cylinder 220 and increase the stability of the first valve 230 when it moves.

[0063] As one possible implementation, such as Figure 1 and Figure 5 As shown, the steam superheater body 300 includes a superheater shell 310, an inner shell 320, a tube sheet 340, a second heat exchange tube assembly 350, and a third valve 360. The superheater shell 310 is fixedly connected to the furnace drum 110. A heat exchange chamber 311 and a steam chamber 312 are sequentially arranged along the axial direction of the superheater shell 310. A steam inlet 313, a steam outlet 314, and a process gas outlet 315 are provided on the superheater shell 310. The steam inlet 313 communicates with the steam chamber 312 for introducing saturated steam. The steam outlet 314... 4 is used to output superheated steam heated by the second heat exchange tube group 350. The process gas outlet 315 is connected to the heat exchange chamber 311 and is used to output the process gas after secondary heat exchange. The inner shell 320 is fixedly installed in the heat exchange chamber 311. The two ends of the inner shell 320 are open, and the inner shell 320 has a first end and a second end opposite to each other along the axial direction of the superheater tube shell 310. The first end of the inner shell 320 is connected to the gas path regulating device 200 and is sealed to the inner wall of the superheater tube shell 310. The inner shell 320 and the superheater tube shell 310 are connected. A first gap 330 is formed between the 10 tubes. The second end of the inner shell 320 communicates with the first gap 330. The first gap 330 is used for the process gas after secondary heat exchange at the second heat exchange tube group 350. The tube sheet 340 is fixedly connected to the superheater tube shell 310 and is sealed between the heat exchange chamber 311 and the steam chamber 312. The tube sheet 340 is provided with heat exchange tube mounting holes. The second heat exchange tube group 350 is disposed inside the inner shell 320. The heat exchange tubes 400 in the second heat exchange tube group 350 have an inlet end and an outlet end. The heat exchange tubes 400 in the heat exchange tube assembly 350 are used to introduce steam. The inlet end is connected to the steam inlet 313 through the steam chamber 312, and the outlet end is connected to the steam outlet 314. The heat exchange tubes 400 in the second heat exchange tube assembly 350 are all sealed and installed in the heat exchange tube mounting holes. The third valve 360 ​​is set on the inner shell 320. The opening and closing of the third valve 360 ​​controls the opening and closing of the inner shell 320 and the first gap 330. Along the flow direction of the process gas, the third valve 360 ​​is located upstream of the second heat exchange tube assembly 350.

[0064] Specifically, in the structure of the steam superheater body 300 provided in this embodiment, the superheater shell 310 serves as a pressure-bearing outer shell and is fixedly connected to the furnace cylinder 110 of the waste heat boiler 100. Its interior is axially divided into a heat exchange chamber 311 and a steam chamber 312. The inner shell 320 is fixed within the heat exchange chamber 311, with both ends connected. The first end is connected to the gas path regulating device 200, and the second end is connected to the first gap 330. The first gap 330 is used as a passage for the secondary heat exchange after passing through the second heat exchange tube group 350. The process gas flow channel; the tube sheet 340 is sealed and installed between the heat exchange chamber 311 and the steam chamber 312, and the heat exchange tube installation hole opened on the tube sheet 340 passes through the heat exchange tube 400 of the second heat exchange tube group 350; the second heat exchange tube group 350 is placed in the inner shell 320, and the air inlet end of its heat exchange tube 400 is connected to the steam inlet 313 through the steam chamber 312, and the air outlet end is connected to the steam outlet 314; the third valve 360 ​​is set on the inner shell 320 and connects to the first gap 330. During operation: After passing through the gas path regulating device 200, the process gas enters the inner shell 320 and splits into two paths: When the third valve 360 ​​is opened, part of the process gas flows directly out of the inner shell 320 from the third valve 360 ​​and is quickly discharged through the process gas outlet 315 opened on the superheater tube shell 310 (this part of the process gas does not participate in the subsequent heat exchange at the second heat exchange tube group 350), and the other part of the process gas, after heat exchange at the second heat exchange tube group 350, enters the first gap 330 from the second end of the inner shell 320 and then exits from the process gas outlet 315. When the third valve 360 ​​is closed, all the process gas exchanges heat with the second heat exchange tube group 350 and flows through the second end of the inner shell 320, enters the first gap 330, and is discharged at the process gas outlet 315. Saturated steam enters the steam chamber 312 from the steam inlet 313, flows from the steam chamber 312 into the inlet end of the heat exchange tube 400 in the second heat exchange tube group 350, absorbs heat inside the heat exchange tube 400 and is converted into superheated steam, then flows from the outlet end of the heat exchange tube 400 to the steam outlet 314 for output. This configuration, through the third valve 360, allows for dynamic diversion and regulation of the process gas flow rate. A portion of the process gas can be discharged first, reducing the flow rate of process gas entering the main body of the steam superheater 300 for heat exchange, thus reducing the subsequent process gas flow load, avoiding insufficient superheating under high load conditions, and enhancing the heat exchange effect.

[0065] It should be noted that the "process gas after secondary heat exchange" mentioned above refers to the process gas after heat exchange with the saturated steam inside the heat exchange tube 400 at the second heat exchange tube group 350.

[0066] Furthermore, such as Figure 6As shown, the main body 300 of the steam superheater also includes a buffer cover 370, which is fixedly connected to the inner shell 320. A cavity is formed between the buffer cover 370 and the outer wall of the inner shell 320. The third valve 360 ​​is located in the cavity. The buffer cover 370 has multiple openings 3701, and the cavity and the first gap 330 are connected through the openings 3701.

[0067] Specifically, the buffer cover 370 is fixedly installed on the outer wall of the inner shell 320, forming a cavity between them, and the third valve 360 ​​is disposed in this cavity; multiple openings 3701 are opened on the surface of the buffer cover 370, and these openings 3701 connect the cavity and the first gap 330. During operation: the process gas flowing out from the third valve 360 ​​first enters the cavity, the high-speed airflow collides and decelerates in the cavity, and then diffuses through the openings 3701 of the buffer cover 370 to the first gap 330, until it is discharged and collected from the process gas outlet 315; large particulate impurities in the process gas collide and deposit on the cavity wall, and the purified process gas flows into the first gap 330 and is discharged through the openings 3701. With this configuration, the buffer cover 370 ensures that when a portion of the process gas, after heat exchange at the second heat exchange tube group 350, enters the first gap 330 from the second end of the inner shell 320 and is discharged and collected from the process gas outlet 315, it is buffered by the buffer cover 370 and will not directly impact the third valve 360, thus eliminating the impact damage of the process gas to the sealing surface of the third valve 360. Furthermore, the design of multiple openings 3701 allows the process gas to be diverted and evenly injected into the first gap 330, avoiding temperature control deviations caused by local eddies. Additionally, the wall surface of the buffer cover 370 can collide and deposit some impurity particles, effectively filtering the process gas and preventing subsequent flow channel blockage.

[0068] It should be noted that a through hole is provided on the steam superheater body 300 at the corresponding position of the third valve 360, for connecting the drive mechanism of the third valve 360 ​​externally. The drive mechanism can drive the third valve 360 ​​to move. The drive mechanism extends out of the steam superheater body 300 through this through hole to form an operating end for operating the third valve 360. The drive mechanism is sealed to the steam superheater body 300 at the through hole.

[0069] As one possible implementation, such as Figure 5 , Figure 7 and Figure 8As shown, the inner shell 320 is provided with a plurality of alternating and spaced first baffles 380 and second baffles 390. The outer edge of the first baffle 380 is fixed to the inner wall of the inner shell 320. The first baffle 380 is provided with a first through hole 3801, and the second baffle 390 is provided with a second through hole 3901. The heat exchange tubes 400 in the second heat exchange tube group 350 pass through the first through hole 3801 and the second through hole 3901. There is an annular gap between the hole wall of the second through hole 3901 and the heat exchange tubes 400 of the second heat exchange tube group 350. The annular gap is used for the passage of process gas. The first baffle 380 is provided with a plurality of first through holes 3802. The first through holes 3802 are used for the passage of process gas.

[0070] Specifically, multiple first baffles 380 and multiple second baffles 390 are alternately arranged in the inner shell 320 along the axial direction of the inner shell 320; the first baffles 380 are provided with a first through hole 3802 and a first through hole 3801 adapted to the diameter of the heat exchange tube 400 in the second heat exchange tube group 350; the second baffles 390 are provided with a second through hole 3901 larger than the outer diameter of the heat exchange tube 400 in the second heat exchange tube group 350; the heat exchange tube 400 in the second heat exchange tube group 350 passes through the first through hole 3801 of all the first baffles 380 and the second through hole 3901 of all the second baffles 390. During operation: After the process gas enters the inner shell 320 through the gas path regulating device 200, a portion of the process gas flows through the first through hole 3802 of the first baffle 380, where the high-speed gas flow is diverted, slowed down, and evenly diffused. The process gas then passes through the gap formed between the second through hole 3901 of the second baffle 390 and the heat exchange tube 400. The reduced flow rate of the process gas flows smoothly downstream under low resistance and finally reaches the process gas outlet 315 through the first gap 330. The diameter of the first baffle 380 is larger than that of the second baffle 390. The outer edge of the first baffle 380 is in contact with and fixed to the inner wall of the inner shell 320. There is an annular gap between the second baffle 390 and the inner wall of the inner shell 320. Therefore, another portion of the process gas flows through the annular gap between the second baffle 390 and the inner wall of the inner shell 320. The above arrangement slows down the flow rate of the process gas, increases the heat exchange efficiency, and enhances the stability of the first baffle 380 and the second baffle 390. Furthermore, the aperture of the second through hole 3901 on the second baffle plate 390 is larger than that of the heat exchange tube 400, which allows the process gas to pass through the gap between the heat exchange tube 400 and the second through hole 3901, providing an additional flow channel for the process gas, increasing the contact area between the process gas and the heat exchange tube 400, and improving the heat exchange capacity.

[0071] It should be noted that the process gas flowing through the annular gap and the first through hole 3802 is a mixture of "process gas after one heat exchange" and "process gas without heat exchange", or it is all process gas after one heat exchange. The process gas flows through the annular gap and the first through hole 3802 to exchange heat with the saturated steam in the heat exchange tube 400 in the second heat exchange tube group 350 to obtain the process gas after two heat exchanges.

[0072] Understandably, when both the first valve 230 and the second valve 240 are open, the "process gas after one heat exchange" and the "process gas without heat exchange" are mixed, and the mixed process gas passes through the aforementioned annular gap and the first through hole 3802; when the first valve 230 is opened and the second valve 240 is closed, all the process gas undergoes heat exchange at the first heat exchange tube group 130, and the "process gas after one heat exchange" flows directly into the second heat exchange tube group 350 to heat the saturated steam in the heat exchange tube 400 into superheated steam.

[0073] As one possible implementation, such as Figure 1 and 10 As shown, the heat exchange tube 400 in the second heat exchange tube group 350 includes an inner sleeve 430 and an outer sleeve 440. The outer sleeve 440 is coaxially sleeved outside the inner sleeve 430, and a second gap 450 is formed between the outer sleeve 440 and the inner sleeve 430. The outer sleeve 440 has a closed end 460 and a steam inlet end that are arranged opposite to each other. A protective cover 420 is fixedly provided on the outside of the closed end 460. The protective cover 420 has two ends fixed on the outside of the closed end 460, and the protective cover 420 and the outer sleeve 440 form a closed cavity. The closed end 460 is located inside the closed cavity. The steam inlet end has a through hole that connects the steam cavity 312 and the second gap 450. The inner sleeve 430 includes two through ends, and one end is connected to the steam outlet 314.

[0074] Specifically, the heat exchange tubes 400 of the second heat exchange tube group 350 adopt a double-layer sleeve design. The outer sleeve 440 is coaxially sleeved outside the inner sleeve 430 to form a second gap 450. One end of the outer sleeve 440 is closed and a protective cover 420 is installed to form a sealed cavity that wraps the closed end 460. The other end has a steam inlet 313 that connects to the steam chamber 312. The inner sleeve 430 is designed to be through at both ends. One end extends to the closed end 460 and the other end connects to the steam outlet 314. During operation: Saturated steam enters the second gap 450 from the steam chamber 312 through the through hole connecting the steam chamber 312 and the second gap 450. The saturated steam flows axially along the heat exchange tube 400 in the second gap 450 to the closed end 460, then turns and enters the inner sleeve 430, finally exiting from the steam outlet 314. When the process gas flows outside the tube, the protective cover 420 isolates the closed end 460 from the direct impact of the high-temperature gas flow, minimizing the thermal impact on the closed end 460 of the heat exchange tube 400. This configuration extends the saturated steam flow path through the annular gap formed between the inner sleeve 430 and the outer sleeve 440, improving heat exchange efficiency. The protective cover 420 is located at the end of the heat exchange tube 400 directly facing the process gas, physically isolating the tube end from the high-temperature erosion caused by the process gas.

[0075] In some embodiments, such as Figure 9 As shown, the outer wall of the outer jacket 440 is also provided with fins 410. The fins 410 are inclined on the outer wall of the outer jacket 440, and their inclination direction intersects the axial direction of the heat exchange tube 400. This arrangement enhances the rigidity of the heat exchange tube 400, increases the heat exchange area, and improves the heat exchange efficiency.

[0076] In some embodiments, the superheater body 300 further includes a central connecting pipe, which is fixedly disposed within the steam chamber 312. The central connecting pipe is connected to the inner sleeve 430 of the heat exchange tube 400 and the steam outlet 314 disposed on the superheater shell 310. During operation, saturated steam enters the steam chamber 312 from the steam inlet 313 and then enters the heat exchange tube 400. After participating in heat exchange in the second gap 450, it is injected into the central connecting pipe through the inner sleeve 430, and then exits and is collected from the steam outlet 314. The central connecting pipe allows the superheated steam formed after heat exchange to be concentrated and collected in the central connecting pipe, increasing the collection efficiency.

[0077] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0078] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A steam superheater characterized by, Includes waste heat boiler, gas path regulating device and main body of steam superheater; The waste heat boiler is located at the inlet end of the main body of the steam superheater along the process gas flow direction. The waste heat boiler includes a furnace drum, a central exhaust pipe and a first heat exchange tube group. The central exhaust pipe and the first heat exchange tube group are located inside the furnace drum. The central exhaust pipe is used to pass high-temperature process gas, and the first heat exchange tube group is arranged around the central exhaust pipe. The gas path regulating device is disposed inside the furnace cylinder. The gas path regulating device includes a first valve, a second valve, and an inner cylinder and an outer cylinder coaxially sleeved together. An annular cavity is formed between the inner cylinder and the outer cylinder. The annular cavity is connected to the first heat exchange tube group for passing the high-temperature process gas after heat exchange. The inner cylinder is connected to the central exhaust pipe for passing the high-temperature process gas. The first valve is disposed on the outer cylinder for controlling the opening and closing of the annular cavity and the main body of the steam superheater. The second valve is disposed on the inner cylinder for controlling the opening and closing of the inner cylinder and the main body of the steam superheater. The outer cylinder and the inner cylinder are both closed at the ends away from the first heat exchange tube assembly. The outer circumferential surface of the outer cylinder is provided with a first opening. The first valve is moved radially along the outer cylinder and disposed in the first opening to control the opening degree of the first opening. One end of the inner cylinder extends out of the outer cylinder away from the first heat exchange tube assembly to form an extension. A second opening is provided on the outer peripheral surface of the extension. The second valve is moved radially along the inner cylinder and disposed in the second opening to control the opening degree of the second opening. The main body of the steam superheater includes: The superheater shell is fixedly connected to the furnace drum. A heat exchange chamber and a steam chamber are sequentially arranged along its axial direction in the superheater shell. The superheater shell has a steam inlet, a steam outlet, and a process gas outlet. The steam inlet is connected to the steam chamber and is used to introduce steam to be heated. The steam outlet is used to output superheated steam. The process gas outlet is connected to the heat exchange chamber and is used to output process gas. An inner shell is fixedly disposed within the heat exchange chamber. The two ends of the inner shell are open, and the inner shell has a first end and a second end opposite to each other along the axial direction of the superheater tube shell. The first end of the inner shell is connected to the gas path regulating device and is sealed to the inner wall of the superheater tube shell. A first gap is formed between the inner shell and the superheater tube shell. The second end of the inner shell is connected to the first gap. The first gap is used for the process gas after heat exchange to pass through. A tube sheet is fixedly connected to the superheater tube shell and is sealed between the heat exchange chamber and the steam chamber. The tube sheet is provided with heat exchange tube mounting holes. The second heat exchange tube assembly is disposed within the inner shell. The heat exchange tubes in the second heat exchange tube assembly have an inlet end and an outlet end. The heat exchange tubes in the second heat exchange tube assembly are used to introduce steam. The inlet end is connected to the steam chamber, and the outlet end is connected to the steam outlet. All heat exchange tubes in the second heat exchange tube assembly are sealed and installed in the heat exchange tube mounting hole. The third valve is disposed on the inner shell and controls the opening and closing of the inner shell and the first gap. Along the process flow direction, the third valve is located upstream of the second heat exchange tube assembly.

2. The steam superheater of claim 1, wherein The first opening has two axial edges parallel to the axial direction of the outer cylinder and two parallel circumferential edges extending circumferentially along the outer cylinder. The two axial edges and the two circumferential edges form the first opening. The first valve includes a first side plate, a top plate, and a second side plate connected in sequence. The first side plate and the second side plate are arranged in parallel. The first side plate and the second side plate have bottom surfaces that can respectively contact and seal with the two axial edges. The two end sides of the first side plate, the second side plate, and the top plate are respectively used to contact and seal with the two circumferential edges.

3. The steam superheater of claim 2, wherein, The outer cylinder is also provided with two first flanges, which are respectively located below the two axial edges. The first flanges extend parallel to the axial edges and protrude radially along the outer cylinder. The side walls of the first side plate and the second side plate are also provided with cantilever arms. Each cantilever arm includes a first part and a second part that are perpendicular to each other. The first part is perpendicular to the side walls of the first side plate and the second side plate. The second part is fixed to the end of the first part away from the side wall and extends downward. The bottom surface of the first part is used to contact and seal with the top surface of the first flange. The side surface of the second part that is close to the first part and parallel to the first side plate and the second side plate is used to contact and seal with the side surface of the first flange.

4. The steam superheater of claim 3, wherein, The outer cylinder is also provided with two second flanges, which are respectively provided at the two circumferential edges. The second flanges extend circumferentially along the outer cylinder and protrude radially along the outer cylinder. The bottom surface of the top plate is used to contact and seal with the top surface of the second flanges.

5. The steam superheater of claim 4, wherein, The second flange is provided with a baffle extending axially toward the first opening along the outer cylinder body. The cantilever is located between the baffle and the first flange. The baffle limits the cantilever in a radial direction parallel to the outer cylinder body to limit the maximum opening position of the first valve relative to the outer cylinder body.

6. The steam superheater according to claim 1, characterized in that, The main body of the steam superheater also includes a buffer cover, which is fixedly connected to the inner shell. A cavity is formed between the buffer cover and the outer wall of the inner shell. The third valve is located in the cavity. The buffer cover has multiple openings, and the cavity and the first gap are connected through the openings.

7. The steam superheater of claim 1, wherein, The inner shell is provided with a plurality of alternating and spaced first baffles and second baffles. The outer edge of the first baffle is sealed and fixed to the inner wall of the inner shell. The first baffle has a first through hole, and the second baffle has a second through hole. The heat exchange tubes in the second heat exchange tube group pass through the first through hole and the second through hole. There is an annular gap between the wall of the second through hole and the heat exchange tube. The annular gap is used for the process gas to pass through. The first baffle has a plurality of first through holes, which are used for the process gas to pass through.

8. The steam superheater of claim 1, wherein, The heat exchange tubes in the second heat exchange tube group include an inner tube and an outer tube. The outer tube is coaxially sleeved outside the inner tube, and a second gap is formed between the outer tube and the inner tube. The outer tube has a closed end and a steam inlet end that are arranged opposite to each other. A protective cover is fixedly provided on the outside of the closed end. The protective cover has two ends fixed on the outside of the closed end, and the protective cover and the outer tube form a closed cavity. The closed end is located inside the closed cavity. The steam inlet end has a through hole that connects the steam cavity and the second gap. The inner tube includes two through ends, and one end is connected to the steam outlet.

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