High-parameter, externally reheated single-passage waste heat boiler for garbage incineration furnace

Abstract

Disclosed in the present invention is a high-parameter, externally reheated single-passage waste heat boiler for a garbage incineration furnace. The high-parameter, externally reheated single-passage waste heat boiler comprises: a flue gas duct, a steam drum and a reheater, wherein the flue gas duct sequentially comprises, heading outward in a flue gas direction, a vertical flue, a horizontal flue and a bent flue; water-cooling walls are provided in the vertical flue as heated evaporation faces for generating saturated steam; the steam drum is arranged above the horizontal flue, is connected to the water-cooling walls and is configured to accommodate saturated steam; the reheater is arranged above the steam drum and connected to the steam drum and a steam turbine exhaust pipe; and reheated steam flows, from the steam turbine exhaust pipe, through a shell of a tube bundle in the reheater, while saturated steam is delivered from the steam drum into the tube bundle of the reheater to transfer heat to the reheated steam. By means of arranging the reheater outside the furnace, contact between the reheater and flue gas is avoided, thereby effectively solving the problem of high-temperature flue gas corroding a heated surface of the reheater inside the boiler, effectively improving the thermal efficiency of a whole plant unit, and reducing the investment cost and the floor area of the boiler without excessively increasing the area of superheaters.

Description

A high-parameter single-channel waste heat boiler with external reheat for waste incinerators Technical Field

[0001] This invention relates to a single-channel vertical boiler and includes a reheat system, and more particularly to a high-parameter waste incinerator external reheat single-channel waste heat boiler. Background Technology

[0002] Compared with other waste treatment technologies such as sanitary landfill and composting, incineration technology has significant advantages such as reduced volume and weight, thorough harmlessness, small footprint, and the ability to use residual heat for heating or power generation, as well as less and more controllable secondary pollution. Therefore, it has gradually become the mainstream technology for urban domestic waste treatment in my country.

[0003] In waste-to-energy incineration technology, the incinerator is the core equipment. Currently, the most widely used and technologically mature types of municipal solid waste incinerators both domestically and internationally include mechanical grate incinerators, fluidized bed incinerators, pyrolysis incinerators, and rotary kiln incinerators. Mechanical grate incinerators employ layered combustion technology, offering advantages such as lower requirements for waste pretreatment, a wide adaptability to different waste calorific values, and simple operation and maintenance. Mechanical grate incinerators are currently the most commonly used, highest-capacity, and most versatile type of municipal solid waste incinerator in the world, with mature and reliable technology. Domestic waste-to-energy plants have evolved their main steam operating parameters from the initial medium-temperature, medium-pressure (4.0 MPa, 400℃) to medium-temperature, sub-high-pressure (6.4 MPa, 450℃) and sub-high-temperature, sub-high-pressure (6.8 MPa, 485℃). In recent years, to further improve economic efficiency, some overseas projects (13 MPa, 440℃) have adopted external reheat technology, utilizing steam extracted from the steam drum to heat the exhaust steam from the high-pressure cylinder. Currently, the overall thermal efficiency of waste-to-energy plants both domestically and internationally has increased from 23% for the initial medium-temperature and medium-pressure units to 31% for the current medium-temperature and ultra-high-pressure reheat units, resulting in a significant improvement in economic efficiency. Domestic manufacturers have also begun to adopt reheat units with higher unit efficiency.

[0004] In existing technologies, the flue gas temperature at the superheater's heating surface is generally designed to be very high in order to reach the design temperature. However, high-parameter reheat boiler units face the problem of high-temperature heating surface corrosion. High flue gas temperature will cause high-temperature corrosion on the furnace wall, resulting in low thermal efficiency, high investment cost, and large footprint. Summary of the Invention

[0005] Based on this, it is necessary to address the above problems. To solve these problems, the present invention provides a high-parameter waste incinerator external reheat single-channel waste heat boiler.

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

[0007] A high-parameter waste incinerator external reheat single-channel waste heat boiler includes:

[0008] The flue, from the direction of flue gas outward, includes a vertical flue, a horizontal flue, and a curved flue. One end of the horizontal flue is vertically connected to the upper end of the vertical flue, forming a first bend. The curved flue is vertically connected to the other end of the horizontal flue, forming a second bend. A water-cooled wall is installed inside the vertical flue, which serves as an evaporative heating surface for generating saturated steam. A steam drum is located above the horizontal flue and is connected to the water-cooled wall to contain the saturated steam. A reheater is located above the steam drum and is connected to the steam drum and the turbine exhaust pipe. Reheated steam flows from the turbine exhaust pipe through the outer shell of the tube bundle inside the reheater. Saturated steam is sent from the steam drum into the tube bundle, transferring heat to the reheated steam.

[0009] In some embodiments, the system further includes a superheater comprising a primary superheater, a secondary superheater, and a tertiary superheater, wherein the secondary and tertiary superheaters are arranged side-by-side in the horizontal flue near the first bend, and the primary superheater is arranged in the horizontal flue near the second bend.

[0010] In some embodiments, the system further includes a furnace connected to the lower end of the vertical flue. Both sides of the furnace and the flue are provided with water-cooled membrane walls. The ends of the water-cooled membrane walls are provided with an upper water-cooled wall header and a lower water-cooled wall header. The upper water-cooled wall header is connected to the steam drum via a steam-water connection pipe, and the lower water-cooled wall header is connected to the steam drum via a drain connection pipe.

[0011] In some embodiments, a grate is also included, wherein the furnace chamber and the grate are connected by a flexible expansion joint.

[0012] In some embodiments, a header temperature regulator is provided between the primary superheater and the secondary superheater, and the header temperature regulator is used to control the temperature of the main steam.

[0013] In some embodiments, the surface of the vertical flue is covered with a refractory material.

[0014] In some embodiments, the upper part of the vertical flue and the ceiling area of ​​the horizontal flue are protected against corrosion using SiC bricks.

[0015] In some embodiments, the system further includes an economizer disposed within the curved flue, the superheater being provided with a first soot blowing device, the economizer being provided with a second soot blowing device, and the superheater and the economizer employing steam cleaning.

[0016] In some embodiments, the secondary superheater and the tertiary superheater further include a mechanical rapping device for dust removal.

[0017] In some embodiments, the secondary superheater and the tertiary superheater are arranged in parallel and in the same direction as the flue gas, while the primary superheater is arranged in parallel and in the opposite direction as the flue gas.

[0018] This invention proposes a high-parameter waste incinerator external reheat single-channel waste heat boiler. By placing the reheater outside the furnace, the reheater is prevented from contacting the flue gas, which can effectively solve the problem of corrosion of the reheater's heating surface by high-temperature flue gas inside the boiler and can effectively improve the thermal efficiency of the entire plant unit.

[0019] Based on different flue gas temperature windows, the tertiary superheater and the secondary superheater are arranged side by side in the high-temperature area at the top of the horizontal flue. This single-channel boiler design can effectively reduce the total length of the boiler, while ensuring that the main steam temperature of the waste heat boiler is increased to 450-480℃ and the reheat steam temperature reaches 400-450℃. It can also improve the safety and reliability of the reheater and the heat exchange efficiency of the boiler, without the need to increase the superheater area too much, thus reducing the investment cost and floor space of the boiler. Attached Figure Description

[0020] Figure 1 is a three-dimensional structural diagram of a high-parameter waste incinerator external reheat single-channel waste heat boiler according to the present invention.

[0021] The markings in the attached diagram are described as follows: 1. Flue; 11. Vertical flue; 111. Water-cooled wall; 112. First bend; 12. Horizontal flue; 123. Second bend; 13. Bent flue; 2. Steam drum; 3. Reheater; 4. Superheater; 41. Primary superheater; 42. Secondary superheater; 43. Tertiary superheater; 44. First soot blowing device; 45. Mechanical rapping device; 5. Furnace; 6. Grate; 7. Economizer. Detailed Implementation

[0022] To facilitate understanding of the present invention, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as "connected" to another element, it can be directly on the other element, or one or more intermediate elements may exist between them. The terms "upper," "lower," "left," "right," "upper end," "lower end," "top," and "bottom," etc., used in this specification 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 the present 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, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0024] To address the problems of high flue gas temperature leading to corrosion of boiler reheaters and furnace walls, low thermal efficiency, high investment costs, and large footprint in existing technologies, a high-parameter external reheat single-channel waste heat boiler for waste incinerators is proposed.

[0025] The following will describe in detail, with reference to Figure 1, a high-parameter waste incinerator external reheat single-channel waste heat boiler provided by an embodiment of the present invention.

[0026] Please refer to Figure 1, which is a three-dimensional structural schematic diagram of a high-parameter waste incinerator external reheat single-channel waste heat boiler according to the present invention.

[0027] A high-parameter waste incinerator external reheat single-channel waste heat boiler includes:

[0028] The flue 1 includes, in sequence from the flue gas direction outward, a vertical flue 11, a horizontal flue 12, and a curved flue 13. One end of the horizontal flue 12 is vertically connected to the upper end of the vertical flue 11 to form a first bend 112. The curved flue 13 is vertically connected to the other end of the horizontal flue 12 to form a second bend 123. A water-cooled wall 111 is provided inside the vertical flue 11, which serves as an evaporative heating surface for generating saturated steam.

[0029] Steam drum 2 is disposed above the horizontal flue 12 and is connected to the water-cooled wall 111 to contain the saturated steam.

[0030] The reheater 3 is located above the steam drum 2. The reheater 3 is connected to the steam drum 2 and the steam turbine exhaust pipe L. Reheated steam flows from the steam turbine exhaust pipe through the outer shell of the tube bundle inside the reheater 3. Saturated steam is sent from the steam drum 2 into the tube bundle to transfer heat to the reheated steam.

[0031] Specifically, high parameters refer to the main steam parameters of the boiler, with a temperature of 450 degrees Celsius and a pressure of over 13 MPa. Waste incinerators need to be equipped with waste heat boilers for heat absorption. The incinerator is used for incineration, and the waste heat boiler is used for heat absorption.

[0032] Multiple parallel pipes form a water-cooled wall 111, which is laid around the furnace 5 and serves as an evaporative heating surface. It is used to absorb the radiant heat from the high-temperature flames and flue gas in the furnace 5, causing the water in the water-cooled wall 111 to vaporize and generate saturated water vapor. The saturated water vapor is then transported to the steam drum 2. Since the flame temperature inside the furnace is high and the flue gas velocity is low, this heat absorption is mainly carried out through radiation. The temperature of the flue gas is cooled to a sufficiently low level at the outlet of the furnace 5 to protect the furnace wall. The vertical flue is equipped with a flue gas deflector to increase flue gas turbulence.

[0033] Because of the presence of the water-cooled wall 111, the flame can only partially or completely avoid contact with the furnace wall, thus playing a protective role. In addition, the water-cooled wall 111 can also suspend the furnace wall and prevent slagging on the furnace wall.

[0034] In existing technologies, reheaters 3 are typically installed inside flue gas 1, using flue gas to heat the reheated steam inside reheaters 3, which then circulates and performs work on the turbine. This invention adds an external reheater 3, which can effectively improve the overall thermal efficiency of the plant unit. Based on different flue gas temperature windows, the tertiary superheater 43 and the secondary superheater 42 are arranged side-by-side in the high-temperature region at the top of the horizontal flue gas 12. Simultaneously, the external reheater 3 is positioned above the top of the steam drum 2. The reheater 3 is connected to the steam drum 2 and the turbine exhaust pipe L. Reheated steam flows from the turbine exhaust pipe L through the outer shell of the tube bundle inside the reheater 3. Saturated steam is sent from the steam drum 2 into the tube bundle. The outer shell of the tube bundle acts as a medium for heat conduction, causing the temperature of the saturated steam inside the tube bundle to decrease and the temperature of the superheated steam outside the tube bundle to increase, thus transferring heat to the reheated steam. Compared to the existing technology that places the reheater 3 inside the flue 1, placing the reheater 3 outside the flue 1 can avoid the reheater 3 outside the furnace coming into contact with the boiler flue gas, thus reducing high-temperature corrosion.

[0035] This single-channel boiler design can effectively reduce the total length of the boiler, increase the main steam temperature of the waste heat boiler to 450-480℃, and the reheat steam temperature to 300-350℃. It can also improve the safety and reliability of the reheater 3 and the heat exchange efficiency of the boiler. It does not require increasing the area of ​​the superheater 4 and reheater 3, thus reducing the investment cost and floor space of the boiler.

[0036] In one embodiment, the system further includes a superheater 4, which includes a primary superheater 41, a secondary superheater 42, and a tertiary superheater 43. The secondary superheater 42 and the tertiary superheater 43 are arranged side by side in the horizontal flue 12 near the first bend 112, and the primary superheater 41 is arranged in the horizontal flue 12 near the second bend 123.

[0037] Specifically, the secondary superheater 42 and the tertiary superheater 43 are symmetrically arranged at the top of the vertical flue 11. Along the flue gas direction, the secondary superheater 42 and the tertiary superheater 43 heat the saturated steam in the steam drum 2, turning the saturated steam into superheated steam. The primary superheater 41 is located after the secondary superheater 42 and the tertiary superheater 43, with the purpose of further heating the superheated steam and raising the temperature of the steam. The secondary superheater 42 and the tertiary superheater 43 are semi-radial type and arranged near the upper outlet of the furnace 5. They absorb the heat radiation of the flame in the furnace 5 and absorb the heat of the flue gas flowing through them by convection. The primary superheater 41 is convection type and is mainly distributed in the convection flue 1 outside the furnace 5. It absorbs the heat of the flue gas by convection heat transfer. The width of the secondary superheater 42 and the tertiary superheater 43 is half that of the primary superheater 41.

[0038] The various superheaters 4 work together in the boiler to ensure that the steam reaches the required superheat temperature and pressure, thereby improving the efficiency and quality of the boiler system.

[0039] In one embodiment, the furnace 5 is further included, which is connected to the lower end of the vertical flue 11. Both sides of the furnace 5 and the flue 1 are provided with membrane water-cooled walls 111. The ends of the membrane water-cooled walls 111 are provided with an upper water-cooled wall header 113 and a lower water-cooled wall header 114. The upper water-cooled wall header 113 is connected to the steam drum 2 through a steam-water connection pipe, and the lower water-cooled wall header 114 is connected to the steam drum 2 through a drain connection pipe.

[0040] The water in the membrane water-cooled wall 111 is heated and becomes a water-vapor mixture. It rises and flows to the upper water-cooled wall header 113. The water vapor in the upper water-cooled wall header 113 flows to the steam drum 2. The water in the steam drum 2 flows from the downcomer to the lower water-cooled wall header 114, and then enters the water-cooled wall 111, and so on.

[0041] Membrane water-cooled wall 111 is a specific type of water-cooled wall 111. It is composed of finned tubes welded together or plain tubes and flat steel strips welded together to form an airtight screen. It has good furnace airtightness, which can significantly reduce furnace air leakage. It is suitable for slightly positive pressure combustion. It has good furnace airtightness, which ensures that the furnace has good tightness. For negative pressure boilers, this can reduce the furnace air leakage coefficient, thereby improving the combustion conditions in the furnace, increasing the effective radiant heating area, and helping to save steel consumption.

[0042] The membrane water-cooled wall 111 is applied to the furnace 5 to form a water-cooled furnace. Because the water-cooled furnace absorbs the radiant heat inside the furnace, the temperature of the furnace wall is reduced, thereby protecting the furnace wall from high-temperature damage. By absorbing heat radiation through the water-cooled furnace, the furnace wall structure can be simplified and the weight of the furnace wall can be reduced. The water-cooled furnace cools the flue gas to a sufficiently low temperature, which helps to prevent slagging at the outlet of the furnace 5. The water-cooled furnace is designed to cool the furnace 5 and prevent high-temperature damage, while also realizing multiple functions such as cooling, heating and evaporation.

[0043] In one embodiment, a grate 6 is also included, and the furnace chamber 5 is connected to the grate 6 by a flexible expansion joint.

[0044] Specifically, the grate 6 is located at the bottom of the furnace 5 and includes a drying section, a pyrolysis section, a combustion section, and a burnout section. Below the grate 6 is the incinerator, and above the grate 6 is the waste heat furnace (also known as a waste heat boiler). The flexible expansion joint is used to connect the furnace 5 and the grate 6, absorb the displacement caused by thermal expansion and contraction, and reduce the pressure on the connection between the grate 6 and the furnace 5. The flexible expansion joint allows the furnace 5 and the grate 6 to move freely under different temperature, pressure, or vibration conditions, reduce the stress in the furnace 5, and protect the furnace 5 and the grate 6 from damage.

[0045] When the connection between the furnace 5 and the grate 6 expands due to heat or contracts due to cooling, the expansion joint will expand and contract accordingly, preventing excessive stress concentration at a single point between the furnace 5 and the grate 6. It can also effectively absorb the vibration generated during the operation of the furnace 5 and the grate 6, reduce noise, ensure stable operation of the connection between the furnace 5 and the grate 6, extend the service life of the furnace 5 and the grate 6, and reduce the cost of the boiler.

[0046] In one embodiment, a header temperature regulator 46 is provided between the primary superheater 41 and the secondary superheater 42, and the header temperature regulator 46 is used to control the temperature of the main steam.

[0047] Specifically, the function of the header temperature regulator 46 is to adjust the temperature of the main steam within the design range. When the temperature of the main steam is too high, it will be lowered. When the main steam temperature exceeds the design temperature, the header temperature regulator 46 will open, and low-temperature water will be sprayed in to lower the temperature. During normal operation, a certain amount of low-temperature desuperheating water will be sprayed into the header temperature regulator 46, and the temperature will be adjusted by regulating the amount of water.

[0048] Boiler operation requires stable main steam pressure and temperature. However, during normal operation, the boiler load can be unstable, causing the main steam temperature to fluctuate. If not controlled, this can lead to thermal stress fatigue of the metal, which is detrimental to the steam pipes and turbine, and may even exceed the allowable temperature of the metal, posing a safety hazard. Therefore, the header temperature regulator 46 can improve the boiler's thermal efficiency and safety.

[0049] In one embodiment, the surface of the vertical flue 11 is covered with refractory material.

[0050] Specifically, the surface of the vertical flue 11 is a membrane water-cooled wall 111. The refractory material has the characteristics of high temperature resistance, corrosion resistance and wear resistance, which can meet the usage requirements of the furnace zone 5. The purpose of the selected refractory material is to provide heat insulation and avoid high temperature corrosion, and to improve the service life of the boiler.

[0051] In one embodiment, the upper part of the vertical flue 11 and the ceiling area of ​​the horizontal flue 12 are protected against corrosion using SiC bricks.

[0052] Specifically, silicon carbide refractories, with their excellent thermal stability, wear resistance and chemical erosion resistance, can remain stable at temperatures up to 2700 degrees Celsius, have good resistance to slag, and reduce the corrosive effect of horizontal flue 12.

[0053] Meanwhile, the sidewalls located in the furnace chamber 5 area are made of high-alumina refractory material to avoid high-temperature corrosion.

[0054] In one embodiment, the system further includes an economizer 6 disposed within the curved flue 13, a first soot blowing device 44 provided for the superheater 4, and a second soot blowing device 61 provided for the economizer 6. The superheater 4 and the economizer 6 are cleaned with steam.

[0055] Specifically, the economizer 6 includes a multi-stage economizer, installed within a U-shaped curved flue 13. Utilizing the heat from the boiler tail flue gas, it heats the boiler feedwater used to supplement the steam drum 2, preventing a temperature drop during steam drum 2 replenishment. Simultaneously, it lowers the exhaust gas temperature. As the boiler feedwater passes through the economizer 6, its temperature increases, while the exhaust gas temperature decreases, reducing heat loss, saving fuel, and improving boiler efficiency.

[0056] Steam cleaning uses high-pressure steam as the working medium. Through the soot blowing channel and soot blower, the high-pressure steam is sprayed onto the heating surface to remove ash. It is mainly used for cleaning waste heat boilers and can effectively remove ash accumulation on the boiler heating surface, thereby improving the boiler's operating efficiency and safety.

[0057] Steam cleaning includes the following steps: High-pressure steam is sprayed onto the boiler's heat exchange surface through soot blowing pipes and soot blowers. The impact kinetic energy of the high-pressure steam peels off the accumulated ash, which is then carried out of the boiler by the power of the flue gas and the gravity of the dust particles. Steam cleaning is simple to operate, highly efficient, and suitable for removing stubborn ash that is difficult to remove mechanically. It effectively removes ash from boiler heating surfaces, improves boiler thermal efficiency, and reduces safety hazards caused by ash accumulation.

[0058] In one embodiment, the secondary superheater 42 and the tertiary superheater 43 further include a mechanical rapping device 45 for ash removal.

[0059] Specifically, mechanical cleaning uses mechanical equipment to generate vibration force to clean the secondary superheater 42 and the tertiary superheater 43, causing the dust attached to them to fall off, which helps to improve heat transfer efficiency. The advantages of mechanical cleaning are simple operation and low cost, and it is suitable for large-scale and high-frequency use.

[0060] In one embodiment, the secondary superheater 42 and the tertiary superheater 43 are arranged in parallel and in the same direction as the flue gas, while the primary superheater 41 is arranged in parallel and in the opposite direction as the flue gas.

[0061] Specifically, superheater 4 is located above horizontal flue 12 and consists of three stages: a secondary stage SH2 (in-line and co-flow arrangement), a tertiary stage SH3 (in-line and co-flow arrangement), and a primary stage SH1 (in-line and counter-flow arrangement) arranged along the flue gas flow direction. A primary stage water spray desuperheater is employed, using a sleeve structure. The tertiary superheater 43 uses φ70×8 TP310H tubes, the secondary superheater 42 uses φ70×8 TP310H tubes, and the primary superheater 41 uses φ70×8.8 SA210A1 tubes. Steam flow direction: Steam is drawn from the steam drum 2 tubes into the primary (low-temperature) superheater 4. Steam is then drawn from one side of the outlet header of the primary (low-temperature) superheater 4 into the secondary (medium-temperature) superheater 4 and the tertiary (high-temperature) superheater 4. After the above process, the steam reaches 485℃ at the outlet header of the high-temperature superheater 4. All three superheaters 43 adopt a serpentine tube structure and are supported on the header of the horizontal flue 12. This structure facilitates installation and maintenance of the superheater 4.

[0062] The technical problem to be solved by this invention is the corrosion of high-temperature heating surfaces in high-parameter reheat boiler units. The high temperature of the flue gas will cause high-temperature corrosion on the furnace wall.

[0063] By placing the reheater 3 outside the furnace, the heating section of the reheater 3 is directly connected to the steam drum 2. The saturated steam of the steam drum 2 fills the entire interior of the reheater 3. The reheated steam that needs to be heated exchanges heat with the saturated steam of the steam drum 2 through the tube bundle via the reheater 3. The saturated steam of the steam drum 2 is cooled and condensed into water, which flows naturally into the boiler steam-water system by gravity. This avoids the reheater 3 from contacting the flue gas and can effectively solve the problem of corrosion of the heating surface by high-temperature flue gas inside the boiler.

[0064] Beneficial Effects: This invention provides a high-parameter waste incinerator external reheat single-channel waste heat boiler. By adding a reheater 3 outside the furnace, contact between the external reheater 3 and the boiler flue gas can be avoided, reducing high-temperature corrosion. The tertiary superheater 43 and the secondary superheater 42 are arranged side-by-side in the high-temperature area at the top of the horizontal flue duct 12, where the flue gas temperature is 850℃. Simultaneously, the reheater 3 is positioned above the top of the steam drum 2, effectively improving the overall plant unit thermal efficiency. The single-channel boiler design effectively reduces the total boiler length while ensuring the main steam temperature of the waste heat boiler reaches 450-480℃ and the reheat steam temperature reaches 300-350℃. It also improves the safety and reliability of the reheater 3 and the boiler's heat exchange efficiency without requiring excessive superheater 4 and reheater 3 area, thus reducing boiler investment costs and floor space.

[0065] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Under the concept of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present invention as described above. For the sake of brevity, they are not provided in detail. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-parameter waste incinerator external reheat single-pass waste-heat boiler, characterized in that, include: The flue, from the direction of flue gas outward, includes a vertical flue, a horizontal flue, and a curved flue. One end of the horizontal flue is vertically connected to the upper end of the vertical flue to form a first bend. The curved flue is vertically connected to the other end of the horizontal flue to form a second bend. A water-cooled wall is provided inside the vertical flue, which serves as an evaporative heating surface for generating saturated steam. A steam drum is disposed above the horizontal flue and is connected to the water-cooled wall to contain the saturated steam. A reheater is located above the steam drum and is connected to the steam drum and the turbine exhaust pipe. Reheated steam flows from the turbine exhaust pipe through the outer shell of the tube bundle inside the reheater. Saturated steam is sent from the steam drum into the tube bundle to transfer heat to the reheated steam.

2. A high-parameter waste incineration furnace outer reheating single-pass waste heat boiler according to claim 1, characterized in that, It also includes a superheater, which includes a primary superheater, a secondary superheater and a tertiary superheater. The secondary superheater and the tertiary superheater are arranged side by side in the horizontal flue near the first bend, and the primary superheater is arranged in the horizontal flue near the second bend.

3. The high-parameter waste incineration furnace external reheat single-pass waste heat boiler according to claim 1, characterized in that, It also includes a furnace, which is connected to the lower end of the vertical flue. Both sides of the furnace and the flue are provided with water-cooled membrane walls. The ends of the water-cooled membrane walls are provided with an upper water-cooled wall header and a lower water-cooled wall header. The upper water-cooled wall header is connected to the steam drum through a steam-water connection pipe, and the lower water-cooled wall header is connected to the steam drum through a drain connection pipe.

4. A high-parameter waste incineration furnace outer reheating single-pass waste heat boiler according to claim 3, characterized in that, It also includes a grate, and the furnace chamber and the grate are connected by a flexible expansion joint.

5. A high-parameter waste incineration furnace outer reheating single-pass waste heat boiler according to claim 1, characterized in that, A header temperature regulator is provided between the primary superheater and the secondary superheater, and the header temperature regulator is used to control the temperature of the main steam.

6. A high-parameter waste incineration furnace outer reheating single-pass waste heat boiler according to claim 1, characterized in that, The surface of the vertical flue is covered with refractory material.

7. A high-parameter waste incineration furnace outer reheating single-pass waste heat boiler according to claim 1, characterized in that, The upper part of the vertical flue and the ceiling area of ​​the horizontal flue are protected against corrosion using SiC bricks.

8. A high parameter waste incinerator external reheat single pass waste heat boiler according to claim 1, characterized in that, It also includes an economizer, which is installed inside the curved flue. The superheater is equipped with a first soot blowing device, and the economizer is equipped with a second soot blowing device. The superheater and the economizer are cleaned with steam.

9. A high-parameter waste incinerator external reheat single-pass waste-heat boiler according to claim 8, characterized in that, The secondary superheater and the tertiary superheater also include a mechanical rapping device for ash removal.

10. A high parameter waste incinerator external reheat single pass waste heat boiler according to claim 1, characterized in that, The secondary and tertiary superheaters are arranged in parallel and in the same direction as the flue gas, while the primary superheater is arranged in parallel and in the opposite direction as the flue gas.

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