Waste heat boiler and waste incineration system

Abstract

The present invention discloses a waste heat boiler, which comprises: a flue, an air duct, a superheater, an evaporator, a dilution gas hole and a drum, wherein the flue is connected to an incinerator, the flue is provided with a dilution gas hole, the air duct is connected to the dilution gas hole, the superheater is installed in the flue, the superheater is located downstream of the dilution gas hole, the evaporator is installed in the flue, the evaporator is located downstream of the superheater, and the drum is connected to each of the superheater and the evaporator. The air duct can transport gas without corrosive medium into the flue through the dilution gas hole, and the gas without corrosive medium can dilute the corrosive medium in the high-temperature flue gas so as to reduce the concentration of the corrosive medium in the high-temperature flue gas, thereby reducing the corrosion rate of the corrosive medium in the high-temperature flue gas on the heating surface of the superheater, thereby increasing the service life of the superheater.

Description

Technical Field

[0001] The present invention relates to the field of waste incineration, and in particular to a waste heat boiler and a waste incineration system. Background Art

[0002] With the acceleration of urbanization in my country, there is a large gap in the demand for domestic waste treatment. The composition of domestic waste is complex. The chlorine and alkali metal elements contained in it enter the flue gas or form fly ash after combustion, causing metal corrosion of the boiler heating surface. The corrosion rate is closely related to the tube wall temperature. When it reaches 500°C, the corresponding tube wall temperature range is 450°C to 550°C, and the corrosion rate increases rapidly. When the steam temperature is 450°C and the steam pressure is 6.5MPa, the superheater heating surface bursts after only 100 days of operation, and the furnace is forced to be shut down for maintenance, affecting normal production. Therefore, to increase the steam temperature, the corrosion problem of the heating surface heat exchange tube must be solved. In the related technology, improving the superheater material or using metal surface modifications such as surfacing and spraying to enhance the corrosion resistance of the superheater heating surface requires the use of a large amount of expensive metal materials such as nickel and chromium, which increases costs. Therefore, there is an urgent need for an economical and affordable waste incineration waste heat boiler suitable for high flue gas temperature. Summary of the invention

[0003] The present invention is based on the inventor's discovery and understanding of the following facts and problems: the corrosive medium in the high-temperature flue gas will corrode the superheater of the waste heat boiler. The greater the concentration of the corrosive medium in the high-temperature flue gas, the faster the superheater will be corroded and the shorter its service life will be. The smaller the concentration of the corrosive medium in the high-temperature flue gas, the slower the superheater will be corroded and the longer its service life will be.

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, an embodiment of the present invention provides a waste heat boiler.

[0006] A waste heat boiler according to an embodiment of the present invention includes:

[0007] A flue, the flue being connected to the incinerator and provided with dilution gas holes;

[0008] an air duct connected to the dilution gas hole;

[0009] a superheater, wherein the superheater is installed in the flue and is located downstream of the dilution gas hole;

[0010] an evaporator installed in the flue, the evaporator being located downstream of the superheater; and

[0011] A boiler drum is connected to each of the superheater and the evaporator.

[0012] According to the waste heat boiler provided in an embodiment of the present invention, the flue has a horizontal section extending along a first horizontal direction, the dilution gas holes are provided on the horizontal section, and each of the superheater and the evaporator is installed in the horizontal section.

[0013] According to the waste heat boiler proposed in an embodiment of the present invention, the flue includes a first side wall and a second side wall opposite to each other in a second horizontal direction, the dilution gas hole includes a plurality of first sub-dilution gas holes and a plurality of second sub-dilution gas holes, the plurality of first sub-dilution gas holes are arranged on the first side wall at intervals along the vertical direction, the plurality of first sub-dilution gas holes are opposite to each other in the vertical direction, the plurality of second sub-dilution gas holes are arranged on the second side wall at intervals along the vertical direction, the plurality of second sub-dilution gas holes are opposite to each other in the vertical direction, the plurality of first sub-dilution gas holes are opposite to each other one by one in the second horizontal direction, and the first horizontal direction is perpendicular to the second horizontal direction.

[0014] The waste heat boiler provided in an embodiment of the present invention further includes an air inlet pipe, and the air duct is connected to the air inlet pipe.

[0015] According to the waste heat boiler provided in the embodiment of the present invention, a valve and a pressure measuring gauge are provided on the air duct.

[0016] According to the waste heat boiler proposed in the embodiment of the present invention, the air duct includes a first main pipe, a second main pipe, a plurality of first branch pipes and a plurality of second branch pipes, each first branch pipe is connected to the first main pipe, each second branch pipe is connected to the second main pipe, the plurality of first branch pipes are connected to the plurality of first sub-dilution gas holes one by one, the plurality of second branch pipes are connected to the plurality of second sub-dilution gas holes one by one, and the first main pipe and the second main pipe are both provided with valves and pressure gauges. .

[0017] According to the waste heat boiler proposed in an embodiment of the present invention, the flue is provided with steam holes, the steam holes include a plurality of first sub-steam holes and a second sub-steam holes, the first side wall is provided with a plurality of first sub-steam holes spaced apart in a vertical direction, the plurality of first sub-steam holes are opposite to each other in a vertical direction, the plurality of first sub-steam holes and the plurality of first sub-dilution gas holes are alternately arranged in the vertical direction, the second side wall is provided with a plurality of second sub-steam holes spaced apart in the vertical direction, the plurality of second sub-steam holes are opposite to each other in a vertical direction, the plurality of second sub-steam holes and the plurality of second sub-dilution gas holes are alternately arranged in the vertical direction, and the plurality of first sub-steam holes and the plurality of second sub-steam holes are opposite to each other in a one-to-one manner in the second horizontal direction.

[0018] According to the waste heat boiler provided in an embodiment of the present invention, the first sub-dilution gas hole is opposite to the first sub-steam hole in a vertical direction, and the second sub-dilution gas hole is opposite to the second sub-steam hole in a vertical direction.

[0019] According to the waste heat boiler proposed in an embodiment of the present invention, the waste heat boiler also includes an economizer, which is arranged downstream of the evaporator, one end of the economizer is connected to an external water supply device, and the other end of the economizer is connected to the boiler drum.

[0020] According to the waste heat boiler provided in an embodiment of the present invention, the waste heat boiler further includes a pre-protection evaporator, which is installed in the flue and is located upstream of the dilution gas hole.

[0021] According to the waste heat boiler provided in the embodiment of the present invention, the diameter of the dilution gas hole is 200-800 mm.

[0022] A waste incineration system comprises a waste heat boiler according to an embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the internal structure of a flue of a waste heat boiler according to an embodiment of the present invention.

[0024] Figure 2 Schematic diagram of the external structure of a flue of a waste heat boiler according to an embodiment of the present invention.

[0025] Figure 3 Schematic diagram of the structure of the air duct of a waste heat boiler according to an embodiment of the present invention.

[0026] Reference numerals:

[0027] Waste heat boiler 100;

[0028] Flue 110, first side wall 111, second side wall 112, superheater 120, dilution gas hole 130, air duct 140, evaporator 150, steam hole 160, economizer 170, pre-protection evaporator 180, boiler drum 190;

[0029] High temperature steam pipe 121, first sub-dilution gas hole 131, second sub-dilution gas hole 132, first main pipe 141, second main pipe 142, valve 143, pressure gauge 144, first sub-steam hole 161, second sub-steam hole 162, economizer water inlet pipe 171;

[0030] A first branch pipe 145, a second branch pipe 146;

[0031] Air inlet duct 200. DETAILED DESCRIPTION

[0032] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0033] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0035] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0037] In the present invention, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0038] The waste heat boiler according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0039] like Figure 1-3 As shown, the waste heat boiler according to the embodiment of the present invention includes a flue 110 , an air duct 200 , a superheater 120 , an evaporator 150 and a boiler drum 190 .

[0040] The superheater 120 is installed in the flue 110 , and the superheater 120 is located downstream of the dilution gas hole 130 ;

[0041] The evaporator 150 is installed in the flue 110 , and the evaporator 150 is located downstream of the superheater 120 ; and

[0042] The drum 190 is connected to each of the superheater 120 and the evaporator 150 .

[0043] The flue 110 is provided with a dilution gas hole 130, and the air duct 140 is connected to the dilution gas hole 130.

[0044] The superheater 120 is installed in the flue 110 and is located downstream of the dilution gas hole 130 (eg Figure 1 As shown, the upstream and downstream positions are determined according to the flue gas flow direction).

[0045] The boiler drum 190 is connected to each of the superheater 120 and the evaporator 150 .

[0046] The evaporator 150 is installed in the flue 110 and is located downstream of the superheater 120 .

[0047] The evaporator 150 is located downstream of the superheater 120 , which means that the high-temperature flue gas in the flue first passes through the superheater and then passes through the evaporator 15 .

[0048] The superheater 120 is located downstream of the dilution gas hole, which means that the high-temperature flue gas in the flue first passes through the dilution gas hole 130 and then passes through the superheater 120 .

[0049] According to the waste heat boiler 100 proposed in an embodiment of the present invention, after the high-temperature flue gas from the incinerator enters the flue 110 from the incinerator, it first exchanges heat with the superheater 120 to heat the saturated steam from the drum 190 into superheated steam, thereby increasing the energy in the steam and transporting the superheated steam to the turbine through the high-temperature steam pipe 121.

[0050] The air duct 140 can transport the gas without corrosive medium to the flue 110 through the dilution gas hole 130. The gas without corrosive medium can dilute the corrosive medium in the high-temperature flue gas to reduce the concentration of the corrosive medium in the high-temperature flue gas. In the process of heat exchange between the high-temperature flue gas and the superheater 120, a large amount of corrosive medium will be carried. At this time, the gas without corrosive medium is transported to the dilution gas hole 130 through the air duct 140, so that the gas without corrosive medium is in the working area of ​​the superheater 120, diluting the corrosive medium in the high-temperature flue gas, thereby reducing the corrosion rate of the heating surface of the superheater 120 by the corrosive medium in the high-temperature flue gas, thereby increasing the service life of the superheater 120. The high-temperature flue gas after heat exchange with the superheater 120 exchanges heat with the evaporator 150, and the water in the evaporator 150 is heated to become saturated steam water vapor, and the saturated steam is sent to the drum 190. (The saturated steam is then heated to superheated steam by the high-temperature flue gas in the superheater).

[0051] Therefore, the waste heat boiler 100 according to the embodiment of the present invention has the advantages of low corrosion degree and long service life of the superheater 120.

[0052] like Figure 1-3 As shown, the waste heat boiler 100 includes a flue 110, an air duct 140, a superheater 120, an evaporator 150 and a drum 190. The flue 110 can be connected to an incinerator for burning garbage so that high-temperature flue gas generated by burning garbage can enter the flue 110.

[0053] In some embodiments, the flue 110 has a horizontal section extending along a first horizontal direction, the dilution gas holes 130 are arranged on the horizontal section, and each of the superheater 120 and the evaporator 150 is installed in the horizontal section. Figure 3 As shown by arrow A in FIG.

[0054] According to the waste heat boiler 100 proposed in the embodiment of the present invention, the flue 110 has a horizontal section, which can make the high-temperature flue gas flow smoothly, so that the high-temperature flue gas can quickly exchange heat with the superheater 120 and the evaporator 150 arranged on the horizontal section, thereby increasing the heat exchange efficiency. The flue gas in the horizontal section can be directly diluted through the dilution gas holes 130, so that the concentration of the corrosive medium in the flue gas is reduced, and the superheater 120 in the horizontal section flue is protected.

[0055] In some embodiments, the flue 110 includes a second horizontal direction (eg Figure 3 The dilution gas holes 130 include a first side wall 111 and a second side wall 112 that are opposite to each other (in the direction indicated by arrow B). The dilution gas holes 130 include a plurality of first sub-dilution gas holes 131 and a plurality of second sub-dilution gas holes 132. The plurality of first sub-dilution gas holes 131 are arranged on the first side wall 111 at intervals along the second horizontal direction, and the plurality of first sub-dilution gas holes 131 are opposite to each other in the second horizontal direction. The plurality of second sub-dilution gas holes 132 are arranged on the second side wall 112 at intervals along the second horizontal direction, and the plurality of second sub-dilution gas holes 132 are opposite to each other in the second horizontal direction. The plurality of first sub-dilution gas holes 131 and the plurality of second sub-dilution gas holes 132 are opposite to each other one by one in the second horizontal direction.

[0056] That is, the number of the first sub-dilution gas holes 131 may be equal to the number of the second sub-dilution gas holes 132, each first sub-dilution gas hole 131 is opposite to a second sub-dilution gas hole 132 in the second horizontal direction, and each second sub-dilution gas hole 132 is opposite to a first sub-dilution gas hole 131 in the second horizontal direction.

[0057] According to the waste heat boiler 100 proposed in the embodiment of the present invention, by providing a plurality of first sub-dilution gas holes 131 opposite to each other in the vertical direction on the first side wall 111 on the second horizontal direction side perpendicular to the first horizontal direction and providing a plurality of second sub-dilution gas holes 132 opposite to each other in the vertical direction on the second side wall 112, it is not only possible to increase the flow rate of the gas without corrosive medium entering the flue 110, but also to make the high-temperature flue gas and the gas more evenly mixed, so as to avoid the local excessive concentration of the corrosive medium in the flue gas. In this way, the corrosion (loss) of the corrosive medium on the heating surface of the superheater 120 can be further reduced.

[0058] The waste heat boiler 100 further includes an air inlet duct 200, and the air duct 140 is connected to the air inlet duct 200. In some embodiments, the air inlet duct 140 is a secondary air duct and / or a purified recycled flue gas duct, and the air duct 140 is connected to at least one of the secondary air duct and the purified recycled flue gas duct.

[0059] According to the waste heat boiler 100 proposed in the embodiment of the present invention, the air duct 140 is connected to at least one of the secondary air duct and the purified recycled flue gas air duct, so that the secondary air and / or the purified recycled flue gas can be used as the gas without corrosive medium. Since the secondary air and the purified recycled flue gas have a certain amount of heat, that is, the secondary air and the purified recycled flue gas have a high temperature, when the secondary air and the purified recycled flue gas enter the horizontal flue, the heat in the high-temperature flue gas is almost not consumed, that is, the temperature of the high-temperature flue gas is basically not reduced, so as to ensure the heat exchange efficiency while reducing the concentration of the corrosive medium.

[0060] In some embodiments, a valve 143 and a pressure measuring gauge 144 are provided on the air duct 140 .

[0061] The waste heat boiler 100 proposed in the embodiment of the present invention can control the flow rate of the gas without corrosive medium entering the horizontal flue through the air duct 140 in real time by arranging the valve 143 and the pressure measuring meter 144 on the air duct 140 .

[0062] In some embodiments, the air duct 140 includes a first main pipe 141, a second main pipe 142, a plurality of first branch pipes 145, and a plurality of second branch pipes 146. Each first branch pipe 145 is connected to the first main pipe 141, and each second branch pipe 146 is connected to the second main pipe 142. The plurality of first branch pipes 145 are connected to the plurality of first sub-dilution gas holes 131 in a one-to-one correspondence, and the plurality of second branch pipes 146 are connected to the plurality of second sub-dilution gas holes 132 in a one-to-one correspondence. The first main pipe 141 and the second main pipe 142 are both provided with a valve 143 and a pressure measuring gauge 144.

[0063] In some embodiments, a steam hole 160 is provided on the flue 110, and the steam hole 160 includes a plurality of first sub-steam holes 161 and a second sub-steam holes 162. A plurality of first sub-steam holes 161 spaced apart along a second horizontal direction are provided on the first side wall 111, and the plurality of first sub-steam holes 161 are opposite to each other in a vertical direction. The plurality of first sub-steam holes 161 and the plurality of first sub-dilution gas holes 131 are alternately arranged in the second horizontal direction. A plurality of second sub-steam holes 162 spaced apart along a second horizontal direction are provided on the second side wall 112, and the plurality of second sub-steam holes 162 are opposite to each other in the second horizontal direction. The plurality of second sub-steam holes 162 and the plurality of second sub-dilution gas holes 132 are alternately arranged in the second horizontal direction, and the plurality of first sub-steam holes 161 and the plurality of second sub-steam holes 162 are opposite to each other in the second horizontal direction.

[0064] The waste heat boiler 100 proposed in the embodiment of the present invention transports steam to the working space of the superheater 120 through the first sub-steam hole 161 and the second sub-steam hole 162, cleans the dust accumulated on the wall tube of the superheater 120, reduces the coverage of the corrosive medium on the heating surface of the superheater 120, and increases the service life of the superheater 120.

[0065] In some embodiments, the first sub-dilution gas holes 131 are opposite to the first sub-steam holes 161 in the second horizontal direction, and the second sub-dilution gas holes 132 are opposite to the second sub-steam holes 162 in the second horizontal direction.

[0066] According to the waste heat boiler 100 proposed in the embodiment of the present invention, the first sub-dilution gas hole 131 is opposite to the first sub-steam hole 161 in the second horizontal direction, and the second sub-dilution gas hole 132 is opposite to the second sub-steam hole 162 in the second horizontal direction, which can facilitate the inspection and management of the external pipeline and the operation of the staff.

[0067] In some embodiments, the waste heat boiler 100 further includes an economizer 170 , which is located downstream of the evaporator 150 , and the economizer 170 is connected to the boiler drum 190 and the water supply device, respectively.

[0068] The economizer 170 is located downstream of the evaporator 150 , which means that the high-temperature flue gas in the flue first passes through the evaporator 150 and then passes through the economizer 170 .

[0069] According to the waste heat boiler 100 proposed in the embodiment of the present invention, the economizer 170 can further utilize the heat of the high-temperature flue gas, and heat the water sent to the economizer 170 through the economizer water inlet pipe 171 and send it to the boiler drum 190.

[0070] In some embodiments, the waste heat boiler further includes a pre-protection evaporator 180 , which is installed in the flue 110 and is located upstream of the dilution gas holes 130 .

[0071] The fact that the pre-protection evaporator 180 is located upstream of the dilution gas hole 130 means that the high-temperature flue gas in the flue first passes through the pre-protection evaporator 180 and then passes through the dilution gas hole 130 .

[0072] According to the waste heat boiler 100 proposed in the embodiment of the present invention, the setting of the pre-protection evaporator 180 can first exchange heat with the high-temperature flue gas, reduce the temperature of the high-temperature flue gas entering the working space of the superheater 120, slow down the speed of high-temperature corrosion of the superheater 120, and increase the service life of the superheater 120.

[0073] In some embodiments, the diameter of the dilution gas hole 130 is 200-800 mm.

[0074] According to the use of the waste heat boiler 100 proposed in the embodiment of the present invention, the aperture of the dilution gas hole is set. When the aperture of the dilution gas hole 130 is less than 200 mm and the aperture of the dilution gas hole 130 is greater than 800 mm, the processing cost is increased. Preferably, the aperture of the dilution gas hole is 600 mm.

[0075] like Figure 1-3As shown, the waste heat boiler 100 proposed according to an embodiment of the present invention includes a flue 110, a pre-protection evaporator 180, 6 dilution gas holes 130, 4 steam holes 160, a superheater 120, an evaporator 150, an economizer 170 and a boiler drum 190.

[0076] Among them, in the flue 110, a pre-protection evaporator 180, a superheater 120, an evaporator 150, and an economizer 170 are arranged from left to right in sequence. The pre-protection evaporator 180 and the evaporator 150 are circulated and connected with the drum 190. The superheater is connected to the drum 190 through a pipeline and is connected to the steam turbine through a high-temperature steam pipe 121. The inlet of the economizer 170 is connected to the water supply device, and the outlet is connected to the drum 190. Three of the six dilution gas holes 130 and two of the six steam holes 160 are alternately arranged on the pre-protection evaporator 180 and the superheater 120. 0, and the three dilution gas holes 130 and the two steam holes 160 have the same axis in the vertical direction, and the other three dilution gas holes 130 and the two steam holes 160 are alternately arranged on the first side wall 112 between the pre-protection evaporator 180 and the superheater 120, and the three dilution gas holes 130 and the two steam holes 160 have the same axis in the vertical direction, and the three dilution gas holes 130 and the two steam holes 160 on the first side wall 111 have a one-to-one correspondence in height with the three dilution gas holes 130 and the two steam holes 160 on the second side wall 112 in the vertical direction.

[0077] The flue 110 includes three sections of return flue and a horizontal section of flue, and the three sections of return flue are composed of water-cooled walls.

[0078] like Figure 3 As shown, the waste heat boiler 100 further includes an air inlet pipe 200 and an air duct 140 , and the air inlet pipe 200 is connected to the air duct 140 .

[0079] The air duct 140 includes a first main pipe 141, a second main pipe 142, three first branch pipes 145, three second branch pipes 146, two valves 143 and three pressure gauges 144. The first main pipe 141 is provided with a valve 143 and a pressure gauge 144, the second main pipe is provided with a valve 143 and a pressure gauge 144, the heights of the three first branch pipes 145 in the vertical direction correspond to the heights of the three first sub-dilution gas holes 131 on the first side wall 111 in the vertical direction and are connected to the three first sub-dilution gas holes 131 in a one-to-one correspondence, the heights of the three second branch pipes 146 in the vertical direction correspond to the heights of the three second sub-dilution gas holes 132 on the second side wall 112 in the vertical direction and are connected to the three second sub-dilution gas holes 132 in a one-to-one correspondence.

[0080] In some embodiments, the dilution gas holes 130 and the steam holes 160 may be square holes, rectangular holes, circular holes, or other hole shapes that are convenient to process.

[0081] A waste incineration system includes a waste heat boiler 100 according to an embodiment of the present invention.

[0082] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A waste heat boiler, characterized in that: include: A flue, the flue is connected to the incinerator, the flue is provided with dilution gas holes, the flue comprises three sections of folded flues, and the three sections of folded flues are composed of water-cooled walls; an air duct connected to the dilution gas hole; a superheater, wherein the superheater is installed in the flue and is located downstream of the dilution gas hole; an evaporator, the evaporator being installed in the flue and being located downstream of the superheater; and a boiler drum connected to each of the superheater and the evaporator; The flue has a horizontal section extending in a first horizontal direction, the dilution gas holes are provided on the horizontal section, and each of the superheater and the evaporator is installed in the horizontal section; The flue includes a first side wall and a second side wall opposite to each other in a second horizontal direction, the dilution gas holes include a plurality of first sub-dilution gas holes and a plurality of second sub-dilution gas holes, the plurality of first sub-dilution gas holes are arranged on the first side wall at intervals in a vertical direction, the plurality of first sub-dilution gas holes are opposite to each other in the vertical direction, the plurality of second sub-dilution gas holes are arranged on the second side wall at intervals in the vertical direction, the plurality of second sub-dilution gas holes are opposite to each other in the vertical direction, the plurality of first sub-dilution gas holes are opposite to each other one by one in the second horizontal direction, and the first horizontal direction is perpendicular to the second horizontal direction.

2. The waste heat boiler according to claim 1, characterized in that: It also includes an air inlet pipe, and the air duct is connected to the air inlet pipe.

3. The waste heat boiler according to claim 1, characterized in that: The air duct is provided with a valve and a pressure measuring gauge.

4. The waste heat boiler according to claim 1, characterized in that: The air duct includes a first main pipe, a second main pipe, a plurality of first branch pipes and a plurality of second branch pipes, each first branch pipe is connected to the first main pipe, each second branch pipe is connected to the second main pipe, the plurality of first branch pipes are connected to the plurality of first sub-dilution gas holes one by one, the plurality of second branch pipes are connected to the plurality of second sub-dilution gas holes one by one, and valves and pressure measuring gauges are provided on the first main pipe and the second main pipe.

5. The waste heat boiler according to claim 1, characterized in that: The flue is provided with steam holes, and the steam holes include a plurality of first sub-steam holes and a second sub-steam holes. The first side wall is provided with a plurality of first sub-steam holes spaced apart in a vertical direction, the plurality of first sub-steam holes are opposite to each other in the vertical direction, and the plurality of first sub-steam holes and the plurality of first sub-dilution gas holes are alternately arranged in the vertical direction. The second side wall is provided with a plurality of second sub-steam holes spaced apart in the vertical direction, the plurality of second sub-steam holes are opposite to each other in the vertical direction, the plurality of second sub-steam holes and the plurality of second sub-dilution gas holes are alternately arranged in the vertical direction, and the plurality of first sub-steam holes and the plurality of second sub-steam holes are opposite to each other one by one in the second horizontal direction.

6. The waste heat boiler according to claim 5, characterized in that: The first sub-dilution gas hole is opposite to the first sub-steam hole in a vertical direction, and the second sub-dilution gas hole is opposite to the second sub-steam hole in a vertical direction.

7. The waste heat boiler according to claim 1, characterized in that: The waste heat boiler further includes a pre-protection evaporator, which is installed in the flue and is located upstream of the dilution gas hole.

8. A garbage incineration system, characterized in that: It comprises a waste heat boiler according to any one of claims 1-7.

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