Boiler air supply mixed hot air heating dehumidification structure

Abstract

The utility model provides a kind of boiler air supply mixed hot air heating dehumidification structure, utilize boiler air supply after the hot air heating of air preheater mixed high moisture content low temperature primary air or secondary air, heating low temperature air reduces relative humidity to reach the purpose of dehumidification and dust removal. The primary air inlet of boiler is connected with the outlet of primary air air preheater by primary air hot air heating pipe, primary air air preheater is connected with primary air fan, primary air fan is connected with primary air inlet pipe, and primary air inlet pipe is inserted into garbage pool interval;The secondary air inlet of boiler is connected with the outlet of secondary air fan by secondary air hot air heating pipe, the inlet of secondary air fan is connected with secondary air inlet pipe, and secondary air inlet pipe is inserted into slag pit interval;The air inlet of first hot air heating branch pipe is connected with primary air hot air heating pipe, and the air outlet of first hot air heating branch pipe is connected with primary air inlet pipe;The air inlet of second hot air heating branch pipe is connected with primary air hot air heating pipe, and the air outlet of second hot air heating branch pipe is connected with secondary air inlet pipe.

Description

Technical Field

[0001] This utility model relates to a boiler air supply and hot air heating and dehumidification structure, which is applied in a municipal solid waste power plant. Background Technology

[0002] Currently, the boiler systems of municipal solid waste power plants have the following two problems: 1. The hot and humid air containing dust in the garbage pit affects the performance of the boiler's air supply system.

[0003] In municipal solid waste power plants, the waste storage time in the waste pits is generally designed to be 7 days. In order to drain the moisture from the waste and increase the calorific value of the waste entering the furnace, the waste needs to be fermented. During the fermentation process, the waste generates heat and produces hot and humid air with a higher temperature than the ambient temperature. During the unloading of garbage trucks and the transfer of waste by grab buckets, dust is often released, and this dust mixes with the hot and humid air. Therefore, hot and humid air with a certain dust content is frequently released from the waste pits.

[0004] In some municipal solid waste power plants in northern China, a waste heating system is installed to promote waste fermentation. This system uses hot air to heat the waste pits and sprays high-temperature hot water into them. The heat and humidity dissipation from the waste pits in these power plants is more pronounced.

[0005] To deodorize, municipal solid waste power plants typically use boiler blowers (primary or secondary blowers) to draw air from the waste pits, maintaining negative pressure to reduce odor diffusion. In the piping system that delivers odorous gas to the boiler, the ambient temperature around the piping often falls below the dew point temperature of the piping. This causes condensation in the hot, humid air, and dust particles in the air adhere to the inner walls of the pipes, the blower blades, and the surface of the air preheater heat exchanger. This exacerbates corrosion, increases the roughness of the pipe walls, adds weight to the blower blades, increases wear on the blades and blower walls, and increases the thermal resistance of the air preheater heat exchanger, severely impacting the service life and performance of the piping system.

[0006] Currently, according to industry surveys, domestic projects lack specific measures to mitigate hot and humid air pollution. They only resort to frequent boiler shutdowns for cleaning, resulting in some projects generating large amounts of wet sludge within their piping systems.

[0007] 2. The hot and humid air containing dust in the slag pit affects the performance of the boiler's secondary air system.

[0008] In municipal solid waste power plants, after the slag is cooled by adding water, dust and water vapor are released during the slag discharge process into the slag pit. This water vapor release is particularly severe under low-temperature conditions, not only corroding the steel structure and equipment within the slag pit but also reducing visibility and affecting the efficiency and safety of hoisting operations. Some projects utilize the boiler's secondary air fans to draw air from the slag pit to improve the environment and remove air containing dust and water vapor.

[0009] When this air enters the boiler's secondary air delivery system, the ambient temperature around the pipeline is often lower than the dew point temperature of the delivery pipeline. As a result, condensation occurs in the hot and humid air. Dust in the hot and humid air adheres to the inner wall of the pipeline, the fan blades, and the surface of the air preheater heat exchanger (if any). This aggravates the corrosion of the pipeline system, increases the roughness of the inner wall of the pipeline, increases the weight of the fan blades, increases the wear of the blades and the inner wall of the fan, and increases the thermal resistance of the air preheater heat exchanger, seriously affecting the service life and performance of the pipeline system.

[0010] Similarly, no domestic projects have specific countermeasures. To avoid this phenomenon, some construction companies have stopped using the secondary air extraction system in the slag pit and added independent dust and mist removal systems to solve the dust and mist problems in the slag pit. Utility Model Content

[0011] The purpose of this utility model is to overcome the above-mentioned deficiencies in the existing technology and provide a boiler air supply mixed hot air heating and dehumidification structure with reasonable structural design. It utilizes the hot air from the boiler air supply after being heated in the air preheater to mix with low-temperature primary or secondary air with high moisture content, thereby heating the low-temperature air and reducing the relative humidity to achieve the purpose of dehumidification and dust removal.

[0012] The technical solution adopted by this utility model to solve the above problems is as follows: a boiler air supply mixing hot air heating and dehumidification structure, wherein the primary air inlet of the boiler is connected to the outlet of the primary air preheater through a primary air hot supply pipe, the inlet of the primary air preheater is connected to the outlet of the primary air fan, the inlet of the primary air fan is connected to the primary air inlet pipe, and the primary air inlet pipe extends into the waste pit; the secondary air inlet of the boiler is connected to the outlet of the secondary air fan through a secondary air hot supply pipe, the inlet of the secondary air fan is connected to the secondary air inlet pipe, and the secondary air inlet pipe extends into the slag pit; characterized in that: it also includes a first hot air supply branch pipe and a second hot air supply branch pipe; the air inlet of the first hot air supply branch pipe is connected to the primary air hot supply pipe, the air outlet of the first hot air supply branch pipe is connected to the primary air inlet pipe, and a first electric valve is installed on the first hot air supply branch pipe; the air inlet of the second hot air supply branch pipe is connected to the primary air hot supply pipe, the air outlet of the second hot air supply branch pipe is connected to the secondary air inlet pipe, and a second electric valve is installed on the second hot air supply branch pipe.

[0013] The connection between the first hot air supply branch pipe and the primary hot air supply pipe of this utility model is close to the air inlet of the primary hot air supply pipe.

[0014] The connection between the first hot air supply branch pipe and the primary air inlet pipe of this utility model is close to the air inlet of the primary air inlet pipe.

[0015] The connection between the second hot air supply branch pipe and the secondary air inlet pipe of this utility model is close to the air inlet of the secondary air inlet pipe.

[0016] Both the No. 1 electric valve and the No. 2 electric valve described in this utility model are regulating valves.

[0017] This utility model includes a first temperature transmitter installed in the garbage pit room and a second temperature transmitter installed on the primary air inlet duct.

[0018] This utility model includes a No. 3 temperature transmitter installed in the slag pit and a No. 4 temperature transmitter installed on the secondary air inlet pipe.

[0019] This utility model has a dust removal bypass on the primary air inlet duct. The dust removal bypass includes a No. 4 electric valve, a dust collector, a dust removal inlet duct, and a dust removal outlet duct. The inlet of the dust collector is connected to the primary air inlet duct through the dust removal inlet duct. The outlet of the dust collector is connected to the primary air inlet duct through the dust removal outlet duct.

[0020] This utility model has a No. 4 electric valve installed on the dust removal air inlet pipe and a No. 3 electric valve installed on the primary air inlet pipe. The No. 3 electric valve is connected in parallel with the dust removal bypass.

[0021] This utility model has a dust removal filter screen installed at the air inlet of the primary air inlet duct.

[0022] Compared with the prior art, this utility model has the following advantages and effects: 1. This utility model reduces the relative humidity of the primary air intake by mixing hot air, making it less likely for hot and humid air to generate condensate in the primary air duct system, thereby reducing the possibility of condensate corrosion of the primary duct system.

[0023] 2. This invention reduces the relative humidity of the primary air intake by mixing hot air, making it less likely for dust-laden hot and humid air to generate dust-laden condensate in the primary air duct system. This reduces the likelihood of dust in the hot and humid air adhering to the inner wall of the duct, the fan blades, and the surface of the air preheater heat exchanger (if any). This reduces corrosion of the duct system, slows down the increase in roughness of the duct inner wall, protects the fan blades from dust adhesion, reduces wear on the blades and the inner wall of the fan, slows down the increase in thermal resistance of the air preheater heat exchanger, and ensures the service life and performance of the duct system.

[0024] 3. This utility model reduces the relative humidity of the secondary air intake by mixing hot air, making it less likely for hot and humid air to generate condensate in the secondary air duct system, thereby reducing the possibility of condensate corrosion of the secondary duct system.

[0025] 4. This invention reduces the relative humidity of the secondary air intake by mixing hot air, making it less likely for dust-laden hot and humid air to produce dust-laden condensate in the secondary air duct system. This reduces the likelihood of dust in the hot and humid air adhering to the inner wall of the duct, the fan blades, and the surface of the air preheater heat exchanger (if any). It also reduces corrosion of the duct system, slows down the increase in roughness of the duct inner wall, protects the fan blades from dust adhesion, reduces wear on the blades and the inner wall of the fan, slows down the increase in thermal resistance of the air preheater heat exchanger, and ensures the service life and performance of the duct system. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this utility model.

[0027] Figure 2 This is a structural schematic diagram of Embodiment 2 of the present invention.

[0028] Figure 3 This is a structural schematic diagram of Embodiment 3 of the present invention.

[0029] Figure 4 This is a structural schematic diagram of Embodiment 4 of the present invention. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and through embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0031] Example 1.

[0032] See Figure 1 In a municipal solid waste incineration power plant, a negative pressure needs to be maintained in the waste pit chamber 2 to reduce odor diffusion. The primary air inlet 14 of the boiler 4 in boiler room 1 is connected to the outlet of the primary air preheater 6 via a primary air hot supply duct 13. The inlet of the primary air preheater 6 is connected to the outlet of the primary air fan 5 via a primary air supply duct 12. The inlet of the primary air fan 5 is connected to the primary air intake duct 11, which extends into the waste pit chamber 2. The primary air fan 5 draws hot, humid air from the waste pit chamber 2 through the inlet 10 of the primary air intake duct 11. This air then enters the primary air fan 5 through the primary air intake duct 11, is pressurized by the primary air fan 5, and is then sent to the primary air preheater 6 for heating via the primary air supply duct 12. Finally, it is sent to the primary air inlet 14 of the boiler 4 via the primary air hot supply duct 13. All pipelines and equipment from the primary air supply duct 11 to the primary air preheater 6 are insulated.

[0033] The inlet of the first hot air supply branch pipe 15 is connected to the primary air hot air supply pipe 13, with the connection point close to the inlet of the primary air hot air supply pipe 13; the outlet of the first hot air supply branch pipe 15 is connected to the primary air inlet pipe 11, with the connection point close to the inlet 10 of the primary air inlet pipe 11. A first electric valve 31 is installed on the first hot air supply branch pipe 15; this first electric valve 31 is a regulating valve. To better mix hot and cold air, the connection section of the first hot air supply branch pipe 15 is inclined or arranged parallel to the primary air inlet pipe 11 within the pipe. A first temperature transmitter 41 is installed in the waste collection room 2, and a second temperature transmitter 42 is installed on the primary air inlet pipe 11. The control system controls the temperature difference (e.g., 5~10℃) or relative humidity difference (e.g., 5%~10%) between temperature transmitter 42 (number two) and temperature transmitter 41 (number one). This control system then adjusts the opening of electric valve 31 on the first hot air supply branch pipe 15. By mixing high-temperature air, the temperature of the air entering the primary air inlet duct 11 is increased, thereby reducing the relative humidity of that portion of the air. With the reduced relative humidity, this air will not produce condensation in the primary air duct system, and dust is less likely to adhere to the duct system. If the air velocity is high enough, most of the dust can be blown into the boiler 4, thus protecting the pipes, equipment, and accessories of the primary air duct system.

[0034] Example 2.

[0035] See Figure 2 Based on Example 1, when the dust content in the air of the waste pit 2 is too high, and if the primary air piping system cannot blow the dust into the boiler 4, or if it is required to reduce the dust content in the air of the primary air piping system to reduce wear on the pipes and equipment, a dust removal device or a dust removal bypass can be installed on the primary air inlet duct 11. In this example, a dust removal bypass is installed on the primary air inlet duct 11, which includes a No. 4 electric valve 34, a dust collector 8, a dust removal inlet duct 17, and a dust removal outlet duct 18.

[0036] The inlet of the dust collector 8 is connected to the primary air inlet duct 11 via a dust collector inlet duct 17, and a No. 4 electric valve 34 is installed on the dust collector inlet duct 17. The outlet of the dust collector 8 is connected to the primary air inlet duct 11 via a dust collector outlet duct 18. A No. 3 electric valve 33 is installed on the primary air inlet duct 11, and the No. 3 electric valve 33 is connected in parallel with the dust collector bypass. After the high-temperature air in the primary air inlet duct 11 is heated and its relative humidity is reduced by mixing with the first hot air supply branch duct 15, the No. 3 electric valve 33 is closed and the No. 4 electric valve 34 is opened by the control system. The air in the duct enters the dust collector 8 through the dust collector inlet duct 17. After being cleaned by the dust collector 8, the clean air is returned to the primary air inlet duct 11 through the dust collector outlet duct 18. To enhance dust removal, a dust removal filter 16 can be installed at the air inlet 10 of the primary air inlet duct 11. Automatic dust removal methods such as compressed air backflushing and mechanical vibration can be used to achieve automatic filtration and cleaning of large dust particles without requiring staff to enter the garbage room 2, which contains odorous and toxic gases (such as CO and H2S), thereby reducing the dust content in subsequent pipelines.

[0037] Example 3.

[0038] See Figure 3In a municipal solid waste incineration power plant, a negative pressure needs to be maintained in the waste pit chamber 2 to reduce odor diffusion. The primary air inlet 14 of the boiler 4 in the boiler room 1 is connected to the outlet of the primary air preheater 6 via a primary air hot supply pipe 13. The inlet of the primary air preheater 6 is connected to the outlet of the primary air fan 5 via a primary air supply pipe 12. The inlet of the primary air fan 5 is connected to the primary air intake pipe 11, which extends into the waste pit chamber 2. The primary air fan 5 draws hot, humid air from the waste pit chamber 2 through the inlet 10 of the primary air intake pipe 11. This air then enters the primary air fan 5 through the primary air intake pipe 11, is pressurized by the primary air fan 5, and is then sent to the primary air preheater 6 for heating via the primary air supply pipe 12. Finally, it is sent to the primary air inlet 14 of the boiler 4 via the primary air hot supply pipe 13. The secondary air inlet 24 of boiler 4 is connected to the outlet of secondary air fan 7 via secondary air hot supply pipe 23. The inlet of secondary air fan 7 is connected to secondary air inlet pipe 22, which extends into the slag pit 3. Primary air fan 5 draws air from slag pit 2, drawing hot and humid air from slag pit 2 through the inlet 10 of primary air inlet pipe 11. The air then enters primary air fan 5 through primary air inlet pipe 11, is pressurized by primary air fan 5, and is sent to primary air preheater 6 for heating through primary air supply pipe 12. Finally, it is sent to primary air inlet 14 of boiler 4 via primary air hot supply pipe 13. Secondary air fan 7 draws air from slag pit 3, drawing hot and humid air from slag pit 3 through the inlet 21 of secondary air inlet pipe 22. The air then enters secondary air fan 7 through secondary air inlet pipe 22, is pressurized by primary air fan 5, and is sent to secondary air inlet 24 of boiler 4 via secondary air hot supply pipe 23. All piping and equipment from the primary air supply duct 11 to the primary air preheater 6 are insulated. All secondary air supply piping systems and equipment are also insulated.

[0039] The inlet of the second hot air supply branch pipe 20 is connected to the primary hot air supply pipe 13; the outlet of the second hot air supply branch pipe 20 is connected to the secondary air inlet pipe 22, with the connection point near the inlet 21 of the secondary air inlet pipe 22; a second electric valve 32 is installed on the second hot air supply branch pipe 20, which is a regulating valve. In order to better mix the hot and cold air, the second hot air supply branch pipe 20 is inclined or arranged parallel to the secondary air inlet pipe 22 at the connection section. Temperature transmitter 43 is installed in the slag pit 3, and temperature transmitter 44 is installed on the secondary air inlet duct 22. The temperature difference (e.g., 5~10℃) or relative humidity difference (e.g., 5%~10%) between temperature transmitter 44 and temperature transmitter 43 is controlled by the control system. The opening of electric valve 32 on the second hot air branch duct 20 is adjusted by the control system. By mixing high-temperature air, the temperature of the air entering the secondary air inlet duct 22 is increased, thereby reducing the relative humidity of the air in this part. After the relative humidity is reduced, this part of the air will not produce condensate in the secondary air pipeline system, and it is not easy for dust in the duct to adhere to the pipeline system. As long as the wind speed is high enough, most of the dust can be blown into the boiler 4, thus protecting the pipeline, equipment and accessories of the secondary air pipeline system.

[0040] Example 4.

[0041] See Figure 4 This embodiment includes all the structures of embodiments 1-3.

[0042] As described above, the primary air system and the secondary air system can be interchanged, or both systems can be used simultaneously. A dust removal system can also be installed in the secondary air system as needed.

[0043] Furthermore, it should be noted that the specific embodiments described in this specification may differ in the shape and name of their components. The above description is merely illustrative of the structure of this utility model. All equivalent or simple variations made based on the structure, features, and principles described in this utility model patent concept are included within the protection scope of this utility model patent. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the structure of this utility model or exceed the scope defined in these claims, all of which should fall within the protection scope of this utility model.

Claims

1. A boiler-fed air mixing and hot air heating and dehumidification structure, wherein the boiler's primary air inlet is connected to the outlet of the primary air preheater via a primary air hot air supply pipe, the inlet of the primary air preheater is connected to the outlet of the primary air fan, the inlet of the primary air fan is connected to the primary air intake pipe, and the primary air intake pipe extends into the waste pit chamber; the boiler's secondary air inlet is connected to the outlet of the secondary air fan via a secondary air hot air supply pipe, the inlet of the secondary air fan is connected to the secondary air intake pipe, and the secondary air intake pipe extends into the slag pit chamber; characterized in that: It also includes a first hot air supply branch pipe and a second hot air supply branch pipe; the air inlet of the first hot air supply branch pipe is connected to the primary air hot air supply pipe, the air outlet of the first hot air supply branch pipe is connected to the primary air inlet pipe, and a No. 1 electric valve is installed on the first hot air supply branch pipe; the air inlet of the second hot air supply branch pipe is connected to the primary air hot air supply pipe, the air outlet of the second hot air supply branch pipe is connected to the secondary air inlet pipe, and a No. 2 electric valve is installed on the second hot air supply branch pipe.

2. The boiler air supply mixing hot air heating and dehumidification structure according to claim 1, characterized in that: The connection between the first hot air supply branch pipe and the primary hot air supply pipe is located near the air inlet of the primary hot air supply pipe.

3. The boiler air supply mixing hot air heating and dehumidification structure according to claim 1, characterized in that: The connection between the first hot air supply branch pipe and the primary air inlet pipe is located near the air inlet of the primary air inlet pipe.

4. The boiler air supply mixing hot air heating and dehumidification structure according to claim 1, characterized in that: The connection between the second hot air supply branch pipe and the secondary air inlet pipe is located near the air inlet of the secondary air inlet pipe.

5. The boiler air supply mixing hot air heating and dehumidification structure according to claim 1, characterized in that: Both the No. 1 and No. 2 electric valves are regulating valves.

6. The boiler air supply mixing hot air heating and dehumidification structure according to claim 1, characterized in that: Temperature transmitter No. 1 is installed in the garbage pit room, and temperature transmitter No. 2 is installed on the primary air inlet duct.

7. The boiler air supply mixing hot air heating and dehumidification structure according to claim 1, characterized in that: Temperature transmitter No. 3 is installed in the slag pit, and temperature transmitter No. 4 is installed on the secondary air inlet duct.

8. The boiler air supply mixing hot air heating and dehumidification structure according to claim 1, characterized in that: A dust removal bypass is installed on the primary air inlet duct. The dust removal bypass includes a No. 4 electric valve, a dust collector, a dust removal inlet duct, and a dust removal outlet duct. The inlet of the dust collector is connected to the primary air inlet duct through the dust removal inlet duct. The outlet of the dust collector is connected to the primary air inlet duct through the dust removal outlet duct.

9. The boiler air supply mixing hot air heating and dehumidification structure according to claim 8, characterized in that: A No. 4 electric valve is installed on the dust removal inlet duct; a No. 3 electric valve is installed on the primary air inlet duct, and the No. 3 electric valve is connected in parallel with the dust removal bypass.

10. The boiler air supply mixing hot air heating and dehumidification structure according to claim 1, characterized in that: A dust removal filter is installed at the air inlet of the primary air intake duct.

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