Steam generator with air preheater

Abstract

The invention relates to the technical field of steam generators, and provides a steam generator with an air preheater, comprising: a steam generator having an evaporation channel and a heating channel; the combustor is arranged on the steam generator, is provided with a preheated air inlet, is communicated with the heating channel and is used for heating the heating channel; the transition smoke box is communicated with the heating channel; the air preheater is provided with a preheating channel and an air flow channel, the preheating channel communicates with the transition smoke box, and the preheating channel is used for preheating air in the air flow channel after smoke is introduced into the preheating channel; and the air flow channel is communicated with the preheated air inlet. By means of the technical scheme, the problem that in the prior art, when the water inlet temperature of a steam generator is high or high-temperature circulating water is used, low-temperature flue gas emission cannot be achieved is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of steam generators, and in particular to a steam generator with an air preheater. Background Art

[0002] A steam generator is a mechanical device that uses the thermal energy of fuel or other energy sources to heat water into hot water or steam. In order to reduce the exhaust temperature, traditional gas steam boilers or steam generators use room temperature water as a heat absorption medium to absorb the heat in the flue gas, thereby reducing the exhaust temperature. Gas steam boilers are generally implemented with economizers, and steam generators are implemented with condensers. However, once the steam condensate is recycled and the water inlet to the boiler or steam generator is high-temperature circulating water, low-temperature flue gas emissions cannot be achieved. Summary of the invention

[0003] The present invention provides a steam generator with an air preheater, which solves the problem in the prior art that the steam generator cannot achieve low-temperature flue gas discharge when the inlet water temperature is high or high-temperature circulating water is used.

[0004] The technical solution of the present invention is as follows: A steam generator with an air preheater, comprising: A steam generator having an evaporation channel and a heating channel; a burner, arranged on the steam generator, having a preheated air inlet, the burner being in communication with the heating channel, and the burner being used to heat the heating channel; A transition smoke box, connected to the heating channel; The air preheater comprises a preheating channel and an air flow channel. The preheating channel is connected to the transition smoke box. After smoke is introduced into the preheating channel, it is used to preheat the air in the air flow channel. The air flow channel is connected to the preheating air inlet.

[0005] Optionally, the burner is arranged on the top surface of the steam generator, and the burner also has a gas inlet, which is connected to the preheated air inlet.

[0006] Optionally, the steam generator comprises: a first box body, the burner being arranged on the first box body; The fin heat exchange tube group is arranged in the first box body, the inner cavity of the tube of the fin heat exchange tube group forms the evaporation channel, and the heating channel is formed between the first box body and the outer wall of the tube of the fin heat exchange tube group.

[0007] Optionally, the fin heat exchange tube group has a water inlet and a steam outlet, and the water inlet is located below the steam outlet; the first box body is divided into a gasification section, an evaporation section and a flue gas condensation section from top to bottom, the steam outlet is located in the gasification section, and the water inlet is located in the flue gas condensation section.

[0008] Optionally, also include: A condensing shell and tube heat exchanger is arranged in the transition smoke box. The condensing shell and tube heat exchanger has a water inlet and a drain outlet. The water inlet is located on the side close to the air preheater, and the drain outlet is located on the side close to the fin heat exchange tube group. The drain outlet is connected to the water inlet. The condensing shell and tube heat exchanger is used to absorb the heat of the flue gas in the transition smoke box.

[0009] Optionally, the air preheater comprises: The second box has a smoke outlet on the top, and the preheating channel is connected to the smoke outlet; There are a plurality of air preheating pipes, each of which is disposed in the second box body, the inner cavity of the air preheating pipe forms the air flow channel, and the outer wall of the air preheating pipe and the second box body form the preheating channel; A converging cover is arranged on one side of the second box body, and the converging cover is communicated with the air flow channel.

[0010] Optionally, the cross-section of the air preheating tube is rectangular, and adjacent air preheating tubes are staggered.

[0011] Optionally, the air preheating pipe has an air inlet end and an air outlet end, and further includes: A blower is arranged on the air inlet end of the air preheating pipe; A delivery pipe has one end connected to the air outlet end of the air preheating pipe and the other end connected to the preheated air inlet.

[0012] Optionally, also include: A water delivery pipe, one end of which is connected to the drain outlet, and the other end of which is connected to the water inlet; A water supply pump is arranged on the water delivery pipe.

[0013] Optionally, also include: A mixer is arranged on the burner, and the preheated air inlet and the fuel gas inlet are connected with the burner through the mixer.

[0014] The working principle and beneficial effects of the present invention are: When the present invention is working, water enters the evaporation channel from one side of the bottom of the steam generator, and then the water flows upward along the evaporation channel. At the same time, the burner located at the top of the steam generator mixes the fuel with the preheated air entering from the preheated air inlet and burns it. The preheated air is used to assist combustion, and the high-temperature flue gas generated flows into the heating channel to heat the water in the evaporation channel. After that, the flue gas enters the preheating channel of the air preheater through the transition smoke box. In this process, the air in the air flow channel is preheated, and the preheated air returns to the burner to participate in combustion, forming a heat recycling system. The air preheater uses the waste heat of the flue gas to preheat the combustion air, which improves the energy utilization rate, effectively reduces the exhaust temperature, and overcomes the problem that the traditional steam generator cannot achieve low-temperature flue gas emission when the inlet water is high-temperature circulating water, thereby reducing energy waste and reducing thermal pollution emissions to the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The preferred implementation modes will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of the present invention.

[0016] Figure 1 It is a schematic diagram of the overall structure of the steam generator of the present invention; Figure 2 for Figure 1 Sectional view at AA; Figure 3 for Figure 1 Sectional view at the middle BB; Figure 4 for Figure 2 A partial enlarged view of point C in the middle; Figure 5 This is a schematic structural diagram of the steam generator of the present invention from a first viewing angle; Figure 6 This is a schematic structural diagram of the steam generator of the present invention from a second viewing angle; Figure 7 This is a schematic diagram of the internal structure of the air preheater of the present invention; Figure 8 for Figure 7 A partial enlarged view of point D in the middle; Fig. 9 This is a working principle diagram of the present invention.

[0017] In the figure: 1. Steam generator, 101. First box, 102. Evaporation channel, 103. Finned heat exchange tube group, 1031. Water inlet, 1032. Steam outlet, 104. Heating channel, 11. Gasification section, 12. Evaporation section, 13. Flue gas condensation section, 2. Burner, 201. Preheating air inlet, 202. Gas inlet, 203. Upper fire grate, 204. Lower fire grate, 205. Mixing zone, 3. Transition Smoke box, 301, cavity, 302, condensing shell and tube heat exchanger, 3021, water outlet, 3022, drain outlet, 4, air preheater, 401, second box body, 402, flue gas outlet, 403, air inlet end, 404, air outlet end, 405, air preheating pipe, 4051, air flow channel, 406, preheating channel, 5, mixer, 6, blower, 7, confluence cover, 8, delivery pipe, 9, water delivery pipe, 10, water pump. DETAILED DESCRIPTION In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0018] In order to simplify the drawings, only the parts related to the invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically shown, or only one of them is marked. In this article, "one" not only means "only one", but also means "more than one", and "several" includes "two" and "more than two".

[0019] In this document, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0021] Reference Figure 1 to Figure 9, which is an embodiment of the present invention, proposes a steam generator 1 with an air preheater 4, including: the steam generator 1 has an evaporation channel 102 and a heating channel 104; the burner 2 is arranged on the steam generator 1, has a preheating air inlet 201, the burner 2 is connected to the heating channel 104, and the burner 2 is used to heat the heating channel 104; the transition smoke box 3 is connected to the heating channel 104; the air preheater 4 has a preheating channel 406 and an air flow channel 4051, the preheating channel 406 is connected to the transition smoke box 3, and the preheating channel 406 is used to preheat the air in the air flow channel 4051 after the flue gas is introduced; the air flow channel 4051 is connected to the preheating air inlet 201.

[0022] In the above scheme, the steam generator 1, the burner 2, the transition smoke box 3 and the air preheater 4 are all arranged on the same base, the evaporation channel 102 is arranged in a serpentine shape, the transition smoke box 3 connects the heating channel 104 and the preheating channel 406 of the air preheater 4, and the transition smoke box 3 is horizontally arranged on the base. The transition smoke box 3 serves as a channel connecting the steam generator 1 and the air preheater 4, and utilizes the heat of the flue gas flowing through the transition smoke box 3 to preheat the air and water.

[0023] Working process: Water enters the evaporation channel 102 from one side of the bottom of the steam generator 1, and then the water flows upward along the evaporation channel 102. At the same time, the burner 2 located at the top of the steam generator 1 mixes the fuel with the preheated air entering from the preheated air inlet 201 for combustion. The preheated air is used to assist combustion, and the high-temperature flue gas generated flows into the heating channel 104 to heat the water in the evaporation channel 102. After that, the flue gas enters the preheating channel 406 of the air preheater 4 through the transition smoke box 3. In this process, the air in the air flow channel 4051 is preheated, and the preheated air returns to the burner 2 to participate in combustion, forming a heat recycling system. The air preheater 4 uses the waste heat of the flue gas to preheat the combustion air, which improves the energy utilization rate, effectively reduces the exhaust temperature, and overcomes the problem that the traditional steam generator 1 cannot achieve low-temperature flue gas emission when the inlet water is high-temperature circulating water, reduces energy waste, and reduces thermal pollution emissions to the environment.

[0024] Furthermore, the burner 2 is arranged on the top surface of the steam generator 1 , and the burner 2 also has a gas inlet 202 , and the gas inlet 202 is connected to the preheated air inlet 201 .

[0025] In the above scheme, the gas enters the burner 2 from the gas inlet 202, and the preheated air enters from the preheated air inlet 201. The two are mixed in the burner 2 and ignited and burned, and the generated high-temperature flue gas is sprayed downward into the heating channel 104 of the steam generator 1. The burner 2 is a plate burner, and the burner 2 can form a plate-shaped flame during the combustion process, so that the fin heat exchange tube group 103 has a large and uniform heating area, and there is almost no flame gathering area, forming a uniform gradient heating area in the heating channel 104 of the steam generator 1, thereby improving the heat exchange efficiency. It should be noted that the burner 2 includes an upper fire grate 203 and a lower fire grate 204, and the fire grate includes an upper fire grate 203 and a lower fire grate 204, and through holes of different shapes and sizes are distributed on the upper fire grate 203 and the lower fire grate 204. When the premixed gas enters from the gas inlet 202, it is first dispersed and scattered by the upper fire grate 203, and then passes through the through holes of the lower fire grate 204. Since the shapes and sizes of the through holes of the upper fire grate 203 and the lower fire grate 204 are different, the premixed gas is dispersed and scattered again, thereby ensuring uniform flame distribution, consistent combustion intensity, more complete combustion, avoiding the formation of flame concentration areas, making the heated body evenly heated, and higher thermal efficiency. In addition, the burner 2 also has a mixing zone 205. The gas and preheated air mixed by the mixer 5 will first enter the mixing zone 205, and then enter the upper fire grate 203 and the lower fire grate 204 after being ignited. The flame formed in this way will enter the steam generator 1 more evenly. In addition, since the upper fire grate 203 and the lower fire grate 204 are distributed with through holes of different shapes and sizes, in actual use, the upper fire grate 203 and the lower fire grate 204 will also produce a vibration effect, and as a result, the burner 2 as a whole will produce a slight vibration effect, which can avoid clogging of the through holes, and no additional air filter is required. It can operate stably for a long time in a dusty environment. Furthermore, the steam generator 1 includes a first box body 101, and the burner 2 is arranged on the first box body 101; the fin heat exchange tube group 103 is arranged in the first box body 101, and the inner cavity of the pipe of the fin heat exchange tube group 103 forms an evaporation channel 102, and a heating channel 104 is formed between the first box body 101 and the outer wall of the pipe of the fin heat exchange tube group 103.

[0026] In the above scheme, water enters the evaporation channel 102 from the water inlet 1031 of the fin heat exchange tube group 103, and the high-temperature flue gas generated by the burner 2 flows in the heating channel 104. The fins of the fin heat exchange tube group 103 increase the heat exchange area, so that the heat is efficiently transferred from the flue gas to the water in the evaporation channel 102, prompting the water to evaporate to form steam, and the steam is discharged from the steam outlet 1032. The multiple fins of the fin heat exchange tube group 103 significantly increase the heat exchange area, improve the heat transfer efficiency, accelerate the evaporation process of water, and increase the steam production speed of the steam generator 1. In addition, the combination of the fin heat exchange tube group 103 and the first box body 101 makes the equipment structure more compact and reduces the overall floor space. It should be noted that the burner 2 and steam generator 1 of the device adopt reverse combustion technology, that is, the flame is ejected downward from the top of the steam generator 1. The advantage of this is that it can avoid the condensed water generated by the flue gas produced by the traditional upward combustion method during the upward flow, which needs to be evaporated again, causing the flue gas condensed water to vaporize repeatedly. At the same time, the condensed water continuously generated during the downward flow of the flue gas washes the fin tubes of the fin heat exchange tube group 103. The fin tubes are like a spray area, avoiding dust accumulation in the low-temperature area of ​​the fin tubes, thereby improving the heat exchange efficiency.

[0027] Furthermore, the fin heat exchange tube group 103 has a water inlet 1031 and a steam outlet 1032, and the water inlet 1031 is located below the steam outlet 1032; the first box body 101 is divided into a gasification section 11, an evaporation section 12 and a flue gas condensation section 13 from top to bottom, the steam outlet 1032 is located in the gasification section 11, and the water inlet 1031 is located in the flue gas condensation section 13.

[0028] In the above scheme, water enters the evaporation channel 102 of the fin heat exchange tube group 103 from the water inlet 1031 located in the flue gas condensation section 13. As the flue gas flows from bottom to top in the heating channel 104, the water is first heated and evaporated in the evaporation section 12, and then further vaporized into high-quality steam in the gasification section 11 and discharged from the steam outlet 1032. In this process, the heat exchange process between the flue gas and water matches the box segmentation, which improves the overall heat exchange effect and steam quality. By rationally zoning the interior of the steam generator 1, the water heating and evaporation process is made more scientific and efficient, the heat of the flue gas is fully utilized, the energy utilization rate is improved, and it is conducive to effectively controlling the steam quality, reducing undesirable phenomena such as steam carrying water, and improving the applicability of steam in industrial applications.

[0029] It should also be noted that the present invention adopts a one-step direct steam generation technology from water inlet-preheating-vaporization-saturation, without a water collecting tank, and the water capacity is less than 30 liters. Inserts are provided in the saturated section finned heat exchange tubes, such as spiral spiral plates, similar to the spiral blade structure, or baffles can be provided at intervals in the finned heat exchange tubes, which can make the water flow in the tube turbulent, greatly improve the heat transfer coefficient, and the steam dryness can be comparable to that of traditional boilers, without the need for additional condensers, and the exhaust gas temperature is less than 60°C.

[0030] Furthermore, it also includes a condensing tube heat exchanger 302, which is arranged in the transition smoke box 3, and the transition smoke box 3 has a cavity 301. The condensing tube heat exchanger 302 is arranged in the cavity 301, and the cavity can flow smoke. The condensing tube heat exchanger 302 has a water inlet 3021 and a drain outlet 3022. The water inlet 3021 is located on the side close to the air preheater 4, and the drain outlet 3022 is located on the side close to the fin heat exchange tube group 103. The drain outlet 3022 is connected to the water inlet 1031. The condensing tube heat exchanger 302 is used to absorb the heat of the smoke in the transition smoke box 3.

[0031] In the above scheme, in the transition smoke box 3, when the smoke flows in from the heating channel 104, the condensing tube heat exchanger 302 introduces water through the water port 3021 to absorb the heat in the smoke, and the heated water flows out from the drain port 3022 and is transported to the water inlet 1031 of the fin heat exchange tube group 103 through the water pipe 9 and the water pump 10, so as to realize the heat recovery and reuse. The condensing tube heat exchanger 302 further recovers the waste heat of the smoke in the transition smoke box 3, improves the energy utilization rate of the entire steam generator 1 system, reduces heat loss, and reduces operating costs. At the same time, by connecting with the water cycle of the fin heat exchange tube group 103, the heat cycle process of the entire equipment is optimized.

[0032] Furthermore, the air preheater 4 includes a second box body 401, a smoke outlet 402 is provided at the top of the second box body 401, and a preheating channel 406 is connected to the smoke outlet 402; there are a plurality of air preheating pipes 405, and the plurality of air preheating pipes 405 are all arranged in the second box body 401, and the inner cavity of the air preheating pipe 405 forms an air flow channel 4051, and a preheating channel 406 is formed between the outer wall of the air preheating pipe 405 and the second box body 401; a collector hood 7 is arranged on one side of the second box body 401, and the collector hood 7 is connected to the air flow channel 4051.

[0033] In the above scheme, the flue gas enters the preheating channel 406 at the bottom of the air preheater 4 from the transition smoke box 3, and the cold air enters the air flow channel 4051 from the air inlet end 403 of the air preheating pipe 405. In the preheating channel 406, the flue gas and the air in the air flow channel 4051 perform heat exchange, and the preheated air is collected by the collector 7 and then flows out, and then is transported to the preheating air inlet 201 of the burner 2 through the delivery pipe 8 to participate in the combustion. The flue gas and air inside the air preheater 4 can fully perform heat exchange, improve the air preheating effect, and then improve the combustion efficiency of the burner 2, and the layout of multiple air preheating pipes 405 is conducive to the compact design of the equipment and reduces space occupation. It should be noted that the collector 7 is not connected to the preheating channel 406, and the air inlet end 403 is located at the upper part of the air preheater 4, specifically near the smoke outlet 402. The collector 7 can transfer the air that has been preliminarily preheated at the upper part of the air preheater 4 to the lower side of the air preheater 4, and then discharge it through the air outlet end 404.

[0034] Furthermore, the cross-section of the air preheating tube 405 is rectangular, and adjacent air preheating tubes 405 are staggered.

[0035] In the above solution, the cross-section of the air preheating tube 405 is rectangular, and adjacent air preheating tubes 405 are staggered.

[0036] Working process: During the air preheating process, the rectangular cross-section air preheating tube 405 increases the contact area and contact time with the flue gas, and the adjacent staggered arrangement makes the flow path of the flue gas in the preheating channel 406 more tortuous, extending the heat exchange time between the flue gas and the air in the air preheating tube 405. The heat exchange efficiency of the air preheater 4 is improved, and the recovery and utilization of the flue gas waste heat is further enhanced, so that the combustion air can be heated to a higher temperature, thereby improving the combustion efficiency and reducing fuel consumption, and it also helps to reduce the volume of the air preheater 4.

[0037] Furthermore, the air preheating pipe 405 has an air inlet end 403 and an air outlet end 404, and also includes: a blower 6 is arranged on the air inlet end 403 of the air preheating pipe 405; one end of the delivery pipe 8 is connected to the air outlet end 404 of the air preheating pipe 405, and the other end is connected to the preheated air inlet 201.

[0038] In the above scheme, the blower 6 is started to force cold air into the air inlet 403 of the air preheating pipe 405. After being preheated in the air flow channel 4051, the cold air is transported from the air outlet 404 to the preheating air inlet 201 of the burner 2 through the delivery pipe 8, and is mixed with the gas for combustion. The whole process maintains a stable air flow and flow rate under the action of the blower 6, ensuring that the combustion process is stable and efficient. The blower 6 provides a stable air supply, which ensures the continuity and stability of the air preheating and combustion process, is conducive to accurately controlling the combustion process, improving the combustion efficiency, and can flexibly adjust the air flow according to the load demand of the steam generator 1, making the equipment operation more intelligent and energy-saving. It should be noted that the blower 6 can also be installed on the delivery pipe 8.

[0039] Furthermore, it also includes a water pipe 9, one end of which is connected to the drain port 3022, and the other end of which is connected to the water inlet 1031; a water pump 10 is arranged on the water pipe 9.

[0040] In the above scheme, the heated water in the condensing tube heat exchanger 302 is transported from the drain port 3022 to the water inlet 1031 of the fin heat exchange tube group 103 through the water pipe 9 under the action of the water supply pump 10, ensuring that the water can continuously and stably circulate in the system and absorb heat to evaporate. The water supply pump 10 provides power for the circulation of water, ensuring the stable operation of the water circulation between the condensing tube heat exchanger 302 and the fin heat exchange tube group 103, improving the reliability and stability of the entire steam generator 1 system, and at the same time helping to optimize the effect of heat recovery and utilization, and improving the overall performance of the equipment.

[0041] Furthermore, it also includes a mixer 5 , which is arranged on the burner 2 , and the preheated air inlet 201 and the gas inlet 202 are connected to the burner 2 through the mixer 5 .

[0042] In the above scheme, the gas enters the mixer 5 from the gas inlet 202, and the preheated air enters the mixer 5 from the preheated air inlet 201. The two are fully mixed in the mixer 5 before entering the burner 2 for combustion, so that the gas and air are mixed more evenly. The existence of the mixer 5 ensures that the gas and the preheated air can be evenly mixed, improves the stability and completeness of the combustion, reduces the incomplete combustion phenomenon, reduces the emission of harmful gases, improves the combustion efficiency, and thus improves the thermal efficiency and environmental performance of the entire steam generator 1.

[0043] Finally, it should be noted that the present invention adopts a post-premixing method to make the fan work under normal temperature air conditions; the mixing zone of the burner 2 is made of all-metal materials to make it resistant to high temperatures; a gas valve is also provided, and the gas valve is arranged on one side of the mixer 5 and communicated with the mixer 5. The mixing zone and the gas valve adopt a connecting pipe with a heat dissipation function to make the gas valve work under normal temperature conditions; the air preheater heat exchange tube adopts a stainless steel flat rectangular steel pipe, which is small in size, low in cost and simple to make; the steam generator 1 adopts a condenser and an air preheater 4 for two-phase heat absorption and cooling, and has high heat exchange efficiency; the steam generator 1 and the air preheater 4 are connected to the transition smoke box 3 with a built-in condensing tube heat exchanger 302, and the steam generator 1 and the air preheater 4 are integrally matched, and the whole machine has a compact structure, beautiful appearance, short process and low resistance.

[0044] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A steam generator with an air preheater, characterized in that: include: A steam generator (1) having an evaporation channel (102) and a heating channel (104); a burner (2), arranged on the steam generator (1), having a preheated air inlet (201), the burner (2) being in communication with the heating channel (104), and the burner (2) being used to heat the heating channel (104); A transition smoke box (3) connected to the heating channel (104); The air preheater (4) comprises a preheating channel (406) and an air flow channel (4051); the preheating channel (406) is in communication with the transition smoke box (3); after smoke is introduced into the preheating channel (406), the air in the air flow channel (4051) is preheated; and the air flow channel (4051) is in communication with the preheating air inlet (201).

2. A steam generator with an air preheater according to claim 1, characterized in that: The burner (2) is arranged on the top surface of the steam generator (1), and the burner (2) also has a gas inlet (202), and the gas inlet (202) is connected to the preheated air inlet (201).

3. A steam generator with an air preheater according to claim 1, characterized in that: The steam generator (1) comprises: A first box body (101), the burner (2) being arranged on the first box body (101); The fin heat exchange tube group (103) is arranged in the first box (101); the inner cavity of the tube of the fin heat exchange tube group (103) forms the evaporation channel (102); and the heating channel (104) is formed between the first box (101) and the outer wall of the tube of the fin heat exchange tube group (103).

4. A steam generator with an air preheater according to claim 3, characterized in that: The fin heat exchange tube group (103) has a water inlet (1031) and a steam outlet (1032), the water inlet (1031) being located below the steam outlet (1032); the first box body (101) is divided into a gasification section (11), an evaporation section (12) and a flue gas condensation section (13) from top to bottom, the steam outlet (1032) being located in the gasification section (11), and the water inlet (1031) being located in the flue gas condensation section (13).

5. A steam generator with an air preheater according to claim 4, characterized in that: Also includes: A condensing shell-and-tube heat exchanger (302) is arranged in the transition smoke box (3), and the condensing shell-and-tube heat exchanger (302) has a water inlet (3021) and a drain outlet (3022), wherein the water inlet (3021) is located on a side close to the air preheater (4), and the drain outlet (3022) is located on a side close to the fin heat exchange tube group (103), and the drain outlet (3022) is connected to the water inlet (1031). The condensing shell-and-tube heat exchanger (302) is used to absorb the heat of the smoke in the transition smoke box (3).

6. The steam generator with an air preheater according to claim 1, characterized in that: The air preheater (4) comprises: The second box (401) has a smoke outlet (402) at the top, and the preheating channel (406) is connected to the smoke outlet (402); There are a plurality of air preheating pipes (405), each of which is arranged in the second box (401); the inner cavity of the air preheating pipe (405) forms the air flow channel (4051); and the outer wall of the air preheating pipe (405) and the second box (401) form the preheating channel (406); A collector cover (7) is arranged on one side of the second box body (401), and the collector cover (7) is in communication with the air flow channel (4051).

7. A steam generator with an air preheater according to claim 6, characterized in that: The cross-section of the air preheating tube (405) is rectangular, and adjacent air preheating tubes (405) are arranged in a staggered manner.

8. The steam generator with an air preheater according to claim 6, characterized in that: The air preheating pipe (405) has an air inlet end (403) and an air outlet end (404), and further comprises: A blower (6) is arranged on the air inlet end (403) of the air preheating pipe (405); A delivery pipe (8) has one end connected to the air outlet end (404) of the air preheating pipe (405), and the other end connected to the preheated air inlet (201).

9. The steam generator with an air preheater according to claim 5, characterized in that: Also includes: A water delivery pipe (9), one end of which is connected to the drain port (3022) and the other end of which is connected to the water inlet (1031); A water supply pump (10) is arranged on the water delivery pipe (9).

10. The steam generator with an air preheater according to claim 2, characterized in that: Also includes: The mixer (5) is arranged on the burner (2), and the preheated air inlet (201) and the gas inlet (202) are connected to the burner (2) through the mixer (5).

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