External reheating single-channel waste heat boiler of high-parameter garbage incinerator

Abstract

The high-parameter garbage incinerator external reheating single-channel waste heat boiler comprises a flue, a steam pocket and a reheater, the flue sequentially comprises a vertical flue body, a horizontal flue body and a bent flue body from the flue gas direction to the outside, a water cooling wall is arranged in the vertical flue body and serves as an evaporation heating surface for generating saturated steam, and the steam pocket is arranged in the horizontal flue body; the steam pocket is arranged above the horizontal flue, connected with the water cooling wall and used for containing saturated steam, the reheater is arranged above the steam pocket and connected to the steam pocket and a steam turbine exhaust pipeline, reheated steam flows through a shell of a pipe bundle in the reheater from a steam turbine exhaust pipe, the saturated steam is conveyed into the pipe bundle of the reheater from the steam pocket, and the saturated steam flows through the steam turbine exhaust pipeline. And the heat is transferred to the reheated steam. By arranging the reheater outside the boiler, the reheater is prevented from making contact with flue gas, the problem that the heating surface of the reheater is corroded by high-temperature flue gas in the boiler can be effectively solved, the heat efficiency of a whole plant unit can be effectively improved, the area of an excessive superheater does not need to be increased, and the investment cost and the occupied area of the boiler are reduced.

Description

Technical Field

[0001] The invention relates to a single-channel vertical boiler comprising a reheating system, in particular to a high-parameter garbage incinerator external reheating single-channel waste heat boiler. Background Art

[0002] Compared with other waste treatment technologies such as sanitary landfill and composting, incineration technology has obvious volume and weight reduction effects, complete harmlessness, and small footprint. In addition, the waste heat can be used for heating or power generation, and the secondary pollution is less and controllable. It has gradually become the mainstream technology for urban domestic waste treatment in my country.

[0003] In the technology of waste incineration power generation, the waste incinerator is the core equipment of the process. At present, the types of domestic waste incinerators that are widely used and relatively mature in technology at home and abroad are mainly mechanical grate furnace, fluidized bed incinerator, pyrolysis incinerator, and rotary kiln incinerator. The mechanical grate furnace adopts layered combustion technology, which has the advantages of low requirements for garbage pretreatment, wide range of garbage calorific value adaptation, and simple operation and maintenance. The mechanical grate furnace is currently the most commonly used, largest processing capacity, and best applicable type of urban domestic waste incinerator in the world, with mature and reliable technology. The main steam operating parameters of domestic waste power plants have developed from the initial medium temperature and medium pressure (4.0Mpa, 400℃) to medium temperature and sub-high pressure (6.4Mpa, 450℃), sub-high temperature and sub-high pressure (6.8Mpa, 485℃). In recent years, in order to further improve economic benefits. Some foreign projects (13Mpa, 440℃) use the furnace reheating technology that uses steam drum extraction to heat the high-pressure cylinder exhaust steam. At present, the thermal efficiency of waste power plants at home and abroad has increased from 23% of the initial medium-temperature and medium-pressure units to 31% of the current medium-temperature and ultra-high-pressure reheat units. The economic efficiency has been significantly improved, and domestic manufacturers have also begun to adopt reheat units with higher unit efficiency.

[0004] In the prior art, the flue gas temperature at the heating surface of the superheater is generally designed to be very high in order to reach the design temperature. However, the boiler high-parameter reheat unit faces the problem of high-temperature heating surface corrosion. The high flue gas temperature will cause high-temperature corrosion to the furnace wall, the thermal efficiency is relatively low, the investment cost is high, and the floor space is large. Summary of the invention

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

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A high-parameter waste incinerator external reheating single-channel waste heat boiler, comprising:

[0008] The flue includes a vertical flue, a horizontal flue and a curved flue in sequence from the flue gas direction outward, wherein one end of the horizontal flue is vertically connected to the upper end of the vertical flue to form a first bending portion, and the curved flue is vertically connected to the other end of the horizontal flue to form a second bending portion. A water-cooled wall is arranged in the vertical flue, and the water-cooled wall serves as an evaporative heating surface for generating saturated steam; a steam drum is arranged above the horizontal flue, and the steam drum is connected to the water-cooled wall to accommodate the saturated steam; a reheater is arranged above the steam drum, and the reheater is connected to the steam drum and a steam turbine exhaust pipe, and the reheated steam flows from the steam turbine exhaust pipe through the outer shell of the tube bundle in the reheater, and the saturated steam is sent from the steam drum to the tube bundle to transfer heat to the reheated steam.

[0009] In some embodiments, a superheater is also included, and the superheater includes a primary superheater, a secondary superheater and a tertiary superheater. The secondary superheater and the tertiary superheater are arranged in parallel 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, it also includes a furnace, which is connected to the lower end of the vertical flue, and the two side walls of the furnace and the flue are provided with water-cooled membrane walls, and the ends of the water-cooled membrane walls are provided with water-cooled wall upper headers and water-cooled wall lower headers, the water-cooled wall upper headers are connected to the steam drum through a steam-water connecting pipe, and the water-cooled wall lower headers are connected to the steam drum through a lower water connecting pipe.

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

[0012] In some embodiments, an inter-header temperature regulator is provided between the primary superheater and the secondary superheater, and the inter-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 refractory material.

[0014] In some embodiments, the upper portion of the vertical flue and the ceiling area of ​​the horizontal flue are anti-corrosive using SiC hanging bricks.

[0015] In some embodiments, an economizer is also included, and the economizer is arranged in the curved flue. The superheater is provided with a first soot blowing device, and the economizer is provided with a second soot blowing device. The superheater and the economizer are cleaned with steam.

[0016] In some embodiments, the secondary superheater and the tertiary superheater also include a mechanical rapping device for cleaning.

[0017] In some embodiments, the secondary superheater and the tertiary superheater are arranged in series and downstream along the direction of the flue gas, and the primary superheater is arranged in series and countercurrently along the direction of the flue gas.

[0018] The present invention proposes a high-parameter waste incinerator external reheating single-channel waste heat boiler, which places the reheater outside the furnace to avoid contact between the reheater and the flue gas, and can effectively solve the problem of the heating surface of the reheater being corroded by the high-temperature flue gas in the boiler, and can effectively improve the thermal efficiency of the whole plant unit.

[0019] The tertiary superheater and the secondary superheater are arranged side by side in the high-temperature area at the top of the horizontal flue according to the different smoke temperature windows. 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 is 400-450℃. It can also improve the safety and reliability of the reheater and the heat exchange efficiency of the boiler without increasing too much superheater area, reducing the investment cost and floor space of the boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of a high-parameter garbage incinerator external reheating single-channel waste heat boiler described in the present invention.

[0021] The symbols in the accompanying drawings are described as follows:

[0022] 1. Flue; 11. Vertical flue; 111. Water-cooled wall; 112. First bending portion; 12. Horizontal flue; 123. Second bending portion; 13. Curved flue; 2. Steam drum; 3. Reheater; 4. Superheater; 41. Primary superheater; 42. Secondary superheater; 43. Tertiary superheater; 44. First sootblowing device; 45. Mechanical rapping device; 5. Furnace; 6. Grate; 7. Economizer. DETAILED DESCRIPTION

[0023] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with 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 another element, or there can be one or more centered elements therebetween. The terms "upper", "lower", "left", "right", "upper end", "lower end", "top" and "bottom" used in this specification indicate an orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0024] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0025] In order to solve the problems in the prior art of high flue gas temperature causing corrosion of the high temperature heating surface of the boiler reheater and the furnace wall, low thermal efficiency, high investment cost and large floor space, a high-parameter waste incinerator external reheating single-channel waste heat boiler is proposed.

[0026] The following will be combined with the attached Figure 1 A high-parameter waste incinerator external reheat single-channel waste heat boiler provided in an embodiment of the present invention is described in detail.

[0027] See also Figure 1 , Figure 1 It is a schematic diagram of the three-dimensional structure of a high-parameter garbage incinerator external reheating single-channel waste heat boiler described in the present invention.

[0028] A high-parameter waste incinerator external reheating single-channel waste heat boiler, comprising:

[0029] The flue 1 includes a vertical flue 11, a horizontal flue 12 and a curved flue 13 in order from the flue gas direction outward, wherein one end of the horizontal flue 12 is vertically connected to the upper end of the vertical flue 11 to form a first bending portion 112, and the curved flue 13 is vertically connected to the other end of the horizontal flue 12 to form a second bending portion 123, and a water-cooled wall 111 is arranged in the vertical flue 11, and the water-cooled wall 111 is used as an evaporation heating surface to generate saturated steam;

[0030] A steam drum 2 is disposed above the horizontal flue 12, the steam drum 2 is connected to the water-cooled wall 111, and is used to contain the saturated steam;

[0031] The reheater 3 is arranged above the steam drum 2. The reheater 3 is connected to the steam drum 2 and the steam turbine exhaust pipe L. The reheated steam flows from the steam turbine exhaust pipe through the outer shell of the tube bundle in the reheater 3, and the saturated steam is sent from the steam drum 2 to the tube bundle to transfer heat to the reheated steam.

[0032] Specifically, high parameters refer to the main steam parameters of the boiler, whose temperature is 450 degrees Celsius and pressure is above 13 MPa. The waste incinerator needs to be equipped with a waste heat boiler for heat absorption. The incinerator is used for incineration, and the waste heat boiler is used to absorb heat.

[0033] A plurality of parallel tubes form a water-cooled wall 111 which is laid around the furnace 5 and serves as an evaporation heating surface for absorbing the radiation heat of the high-temperature flame and furnace smoke in the furnace 5, vaporizing the water in the water-cooled wall 111 to generate saturated water vapor, which is then transported to the steam drum 2. Since the flame temperature in the furnace is relatively high and the smoke velocity is relatively low, this heat absorption is mainly carried out by radiation. The temperature of the smoke is cooled to a sufficiently low level at the outlet of the furnace 5 to protect the furnace wall. The vertical flue is provided with a smoke folding angle to increase smoke disturbance.

[0034] Due to the existence of the water-cooled wall 111, the flame can only partially or completely not touch the furnace wall, thereby playing a protective role. In addition, the water-cooled wall 111 can also suspend the furnace wall and prevent slagging on the furnace wall.

[0035] In the prior art, the reheater 3 is generally arranged in the flue 1, and the flue gas is used to heat the reheated steam in the reheater 3 so that it can work on the turbine cycle. The present invention adds an external reheater 3, which can effectively improve the thermal efficiency of the entire plant unit; according to different flue gas temperature windows, the third-stage superheater 43 and the second-stage superheater 42 are arranged side by side in the high-temperature area at the top of the horizontal flue 12, and the external reheater 3 is arranged above the top of the steam drum 2. The reheater 3 is connected to the steam drum 2 and the steam turbine exhaust pipe L. The reheated steam flows from the steam turbine exhaust pipe L through the outer shell of the tube bundle in the reheater 3, and the saturated steam is sent from the steam drum 2 to the tube bundle. The outer shell of the tube bundle serves as a medium for heat conduction. The temperature of the saturated steam in the tube bundle is reduced, and the temperature of the superheated steam outside the tube bundle is increased, thereby realizing the transfer of heat to the reheated steam. Compared with the prior art in which the reheater 3 is arranged in the flue 1, the reheater 3 is arranged outside the flue 1 to avoid contact between the reheater 3 outside the furnace and the boiler flue gas, thereby reducing high-temperature corrosion.

[0036] 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°C, and the reheat steam temperature to 300-350°C. It can also improve the safety and reliability of the reheater 3 and the heat exchange efficiency of the boiler without increasing the area of ​​the superheater 4 and the reheater 3, thereby reducing the investment cost and floor space of the boiler.

[0037] In one embodiment, a superheater 4 is further included, and the superheater 4 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 in parallel in the horizontal flue 12 near the first bending portion 112, and the primary superheater 41 is arranged in the horizontal flue 12 near the second bending portion 123.

[0038] Specifically, the secondary superheater 42 and the tertiary superheater 43 are symmetrically arranged at the top of the vertical flue 11. Along the direction of the flue gas, the secondary superheater 42 and the tertiary superheater 43 heat the saturated steam in the drum 2 to convert the saturated steam into superheated steam. The primary superheater 41 is arranged after the secondary superheater 42 and the tertiary superheater 43 to further heat the superheated steam to further increase the temperature of the water vapor. The secondary superheater 42 and the tertiary superheater 43 are semi-radiant and arranged near the upper outlet of the furnace 5, absorbing the heat radiation of the flame in the furnace 5 and absorbing the heat of the flue gas flowing through it by convection. The primary superheater 41 is convection and is mainly distributed in the convection flue 1 outside the furnace 5 to absorb the heat of the flue gas by convection heat transfer. The width of the secondary superheater 42 and the tertiary superheater 43 is half of that of the primary superheater 41.

[0039] The superheaters 4 at each stage cooperate with each other 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.

[0040] In one embodiment, it also includes a furnace 5, which is connected to the lower end of the vertical flue 11. Both side walls 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 water-cooled wall upper headers 113 and water-cooled wall lower headers 114. The water-cooled wall upper headers 113 are connected to the steam drum 2 through a steam-water connecting pipe, and the water-cooled wall lower headers 114 are connected to the steam drum 2 through a lower water connecting pipe.

[0041] The water in the membrane water-cooled wall 111 is heated to become a water-vapor mixed state, and flows upward to the water-cooled wall upper header 113. The water vapor in the water-cooled wall upper header 113 flows to the steam drum 2. The water in the steam drum 2 flows from the downcomer to the water-cooled wall lower header 114, and then enters the water-cooled wall 111, circulating in sequence.

[0042] The membrane water-cooled wall 111 is a specific type of water-cooled wall 111, which is composed of finned tubes welded together or bare tubes and flat steel bars welded together to form an airtight screen. It has good furnace 5 airtightness and can significantly reduce furnace 5 air leakage. It is suitable for slightly positive pressure combustion. It has good furnace 5 airtightness and ensures that the furnace 5 has good tightness. For negative pressure boilers, this can reduce the air leakage coefficient of the furnace 5, thereby improving the combustion conditions in the furnace, increasing the effective radiation heating area, and helping to save steel consumption.

[0043] The membrane water-cooled wall 111 is applied to the furnace 5 to form a water-cooled furnace. Since the water-cooled furnace absorbs the radiant heat in the furnace, the temperature of the furnace wall is reduced, thereby protecting the furnace wall from high temperature damage; the water-cooled furnace absorbs heat radiation, 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 original intention of the design of the water-cooled furnace is to cool the furnace 5 to prevent high temperature damage, and it can also realize multiple functions such as cooling, heating and evaporation.

[0044] In one embodiment, a grate 6 is further included, and the furnace 5 and the grate 6 are connected by a flexible expansion joint.

[0045] Specifically, the grate 6 is located at the bottom of the furnace 5, including 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 can realize the free movement of the furnace 5 and the grate 6 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.

[0046] 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 to prevent excessive stress from being concentrated at a certain point of 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 the stable operation of the connection between the furnace 5 and the grate 6, and extend the service life of the furnace 5 and the grate 6, thereby reducing the cost of the boiler.

[0047] In one embodiment, an inter-header temperature regulator 46 is provided between the primary superheater 41 and the secondary superheater 42 , and the inter-header temperature regulator 46 is used to control the temperature of the main steam.

[0048] Specifically, the function of the header temperature regulator 46 is to adjust the temperature of the main steam to operate within the design range. When the temperature of the main steam is too high, the temperature of the main steam is lowered. When the main steam temperature exceeds the design temperature, the header temperature regulator 46 is opened, and low-temperature water is sprayed to reduce the temperature. During normal operation, a certain amount of low-temperature cooling water is sprayed into the header temperature regulator 46, and the temperature is adjusted by adjusting the amount of water.

[0049] Boiler operation requires stable main steam pressure and temperature, but during normal operation, the boiler load will be unstable and the main steam temperature will fluctuate. If it is not controlled, it will cause metal thermal stress fatigue, which is detrimental to steam pipes and steam turbines, and even exceed the allowable temperature of the metal, posing a safety hazard. Therefore, the header temperature regulator 46 can improve the thermal efficiency and safety of the boiler.

[0050] In one embodiment, the surface of the vertical flue 11 is covered with refractory material.

[0051] 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, and can meet the use requirements of the furnace 5 area. The purpose of selecting the refractory material is to insulate and avoid high-temperature corrosion and increase the service life of the boiler.

[0052] In one embodiment, the upper portion of the vertical flue 11 and the ceiling area of ​​the horizontal flue 12 are anti-corrosive using SiC hanging bricks.

[0053] Specifically, the silicon carbide refractory material has excellent thermal stability, wear resistance and chemical corrosion resistance. The silicon carbide refractory material can remain stable at a temperature as high as 2700 degrees Celsius, has good resistance to slag, and reduces the corrosion of the horizontal flue 12.

[0054] At the same time, the side walls located in the furnace 5 area are made of high-aluminum refractory materials to avoid high-temperature corrosion.

[0055] In one embodiment, it also includes an economizer 6, which is arranged in the curved flue 13, the superheater 4 is provided with a first soot blowing device 44, the economizer 6 is provided with a second soot blowing device 61, and the superheater 4 and the economizer 6 are cleaned with steam.

[0056] Specifically, the economizer 6 includes a multi-stage economizer, which is arranged in the curved flue 13, and the curved flue 13 is U-shaped. The heat of the flue gas at the tail end of the boiler is used to heat the boiler feed water used to supplement the drum 2 to avoid lowering the temperature when the drum 2 is replenished with water, and at the same time reduce the exhaust gas temperature. The boiler feed water passes through the economizer 6 to increase the water temperature and reduce the exhaust gas temperature, thereby reducing heat loss, saving fuel, and improving boiler efficiency.

[0057] Steam cleaning uses high-pressure steam as the working medium. Through the soot blowing channel and soot blower, the high-pressure steam is used to blow the heating surface in a spraying manner, and the impact kinetic energy of the high-pressure steam is used to remove the ash. It is mainly used for the cleaning of waste heat boilers. It can effectively remove the accumulated ash on the heating surface of the boiler and improve the operating efficiency and safety of the boiler.

[0058] Steam cleaning includes the following steps: using high-pressure steam to spray high-pressure steam onto the heat exchange surface of the boiler through the soot blowing pipe and soot blower, using the impact kinetic energy of the high-pressure steam to peel off the accumulated ash, and using the power of the flue gas and the gravity of the dust particles to carry it out of the boiler. Steam cleaning is simple to operate and has high cleaning efficiency. It is suitable for removing ash scale that is highly adhesive and difficult to remove mechanically. It can effectively remove the accumulated ash on the heating surface of the boiler, improve the thermal efficiency of the boiler, and reduce the safety hazards caused by ash accumulation.

[0059] In one embodiment, the secondary superheater 42 and the tertiary superheater 43 further include a mechanical rapping device 45 for cleaning.

[0060] Specifically, mechanical cleaning generates vibration force through mechanical equipment to perform vibration cleaning on the secondary superheater 42 and the tertiary superheater 43, so that the dust attached thereto falls off, which is beneficial to improving the heat transfer efficiency. The advantages of mechanical cleaning are simple operation and low cost, and it is suitable for larger scale and higher frequency of use.

[0061] In one embodiment, the secondary superheater 42 and the tertiary superheater 43 are arranged in series and downstream along the direction of the flue gas, and the primary superheater 41 is arranged in series and countercurrently along the direction of the flue gas.

[0062] Specifically, the superheater 4 is arranged at the upper part of the horizontal flue 12, and is divided into three stages. The secondary SH2 (arranged in series and downstream), the tertiary SH3 (arranged in series and downstream), and the primary SH1 (arranged in series and countercurrent) are arranged along the flue gas flow direction, and a primary water spray cooling is adopted, and the water spray cooler adopts a sleeve structure. The third-stage superheater 43 adopts a φ70×8 pipe of material TP310H, the second-stage superheater 42 adopts a φ70×8 pipe of material TP310H, and the first-stage superheater 41 adopts a φ70×8.8 pipe of material SA210A1. Steam flow direction: It is drawn out from the drum 2 pipe and enters the primary (low-temperature) superheater 4. The steam is drawn out from one side of the first-stage (low-temperature) superheater 4 outlet header and enters the secondary (medium-temperature) superheater 4 and the tertiary (high-temperature) superheater 4. The steam that has passed the above process reaches 485°C at the high-temperature superheater 4 outlet header. The three-stage superheater 43 all adopts a serpentine tube structure and is placed on a supporting device on the horizontal flue 12 header. This structure is conducive to the installation and maintenance of the superheater 4.

[0063] The technical problem to be solved by the present invention is that the boiler high parameter reheat unit faces the problem of high temperature heating surface corrosion. The high flue gas temperature will cause high temperature corrosion to the furnace 5 wall.

[0064] By placing the reheater 3 outside the furnace, the heating section of the reheater 3 outside the furnace is directly connected to the drum 2, and the saturated steam of the drum 2 fills the entire interior of the reheater 3 outside the furnace. Then, the reheated steam that needs to be heated passes through the reheater 3 outside the furnace and exchanges heat with the saturated steam of the drum 2 through the tube bundle. The saturated steam of the drum 2 is cooled and condensed into water, which naturally flows into the boiler steam-water system by gravity, avoiding contact between the reheater 3 and the flue gas, and can effectively solve the problem of corrosion of the heating surface by high-temperature flue gas inside the boiler.

[0065] Beneficial effects: The present invention provides a high-parameter waste incinerator external reheating single-channel waste heat boiler. By adding a reheater 3 outside the furnace, the contact between the reheater 3 outside the furnace and the boiler flue gas can be avoided, reducing high-temperature corrosion. According to different flue gas temperature windows, the third-stage superheater 43 and the second-stage superheater 42 are arranged side by side in the high-temperature area at the top of the horizontal flue 12. The flue gas temperature in this area is 850°C. At the same time, the reheater 3 is arranged above the top of the drum 2, which can effectively improve the thermal efficiency of the whole plant unit. The single-channel boiler design can effectively reduce the total length of the boiler, and at the same time can ensure that the main steam temperature of the waste heat boiler is increased to 450-480°C, and the reheat steam temperature reaches 300-350°C. It can also improve the safety and reliability of the reheater 3 and the heat exchange efficiency of the boiler, without increasing the area of ​​the superheater 4 and the reheater 3, reducing the investment cost and floor space of the boiler.

[0066] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may also be combined, the steps may be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Although the present invention is described in detail with reference to the above embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the above embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-parameter waste incinerator external reheat single-channel waste heat boiler, characterized in that: include: The flue includes a vertical flue, a horizontal flue and a curved flue in order from the flue gas direction outward, wherein one end of the horizontal flue is vertically connected to the upper end of the vertical flue to form a first bending portion, and the curved flue is vertically connected to the other end of the horizontal flue to form a second bending portion, and a water-cooled wall is arranged in the vertical flue, and the water-cooled wall is used as an evaporative heating surface to generate saturated steam; A steam drum is arranged above the horizontal flue, the steam drum is connected to the water-cooled wall and is used to contain the saturated steam; A reheater is arranged above the steam drum. The reheater is connected to the steam drum and the steam turbine exhaust pipe. The reheated steam flows from the steam turbine exhaust pipe through the outer shell of the tube bundle in the reheater. Saturated steam is sent from the steam drum to the tube bundle to transfer heat to the reheated steam.

2. A high-parameter waste incinerator external reheat single-channel 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 in parallel in the horizontal flue near the first bend, and the primary superheater is arranged in the horizontal flue near the second bend.

3. A high-parameter waste incinerator external reheat single-channel 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 side walls of the furnace and the flue are provided with water-cooled membrane walls. The ends of the water-cooled membrane walls are provided with a water-cooled wall upper header and a water-cooled wall lower header. The water-cooled wall upper header is connected to the steam drum through a steam-water connecting pipe, and the water-cooled wall lower header is connected to the steam drum through a lower water connecting pipe.

4. A high-parameter waste incinerator external reheat single-channel waste heat boiler according to claim 3, characterized in that: It also includes a grate, and the furnace and the grate are connected by a flexible expansion joint.

5. A high-parameter waste incinerator external reheat single-channel 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 incinerator external reheat single-channel 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 incinerator external reheat single-channel 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 anti-corrosive using SiC hanging bricks.

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

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

10. A high-parameter waste incinerator external reheat single-channel waste heat boiler according to claim 1, characterized in that: The secondary superheater and the tertiary superheater are arranged in series and downstream along the direction of the flue gas, and the primary superheater is arranged in series and countercurrently along the direction of the flue gas.

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