Waste heat utilization system for tail flue gas of garbage incinerator
By setting up a heat exchanger between the dust removal assembly and the chimney at the tail of the garbage incinerator, the waste heat of flue gas is recovered and used to heat the ash transfer system, the problem of insufficient recycling and utilization of waste heat in the boiler economizer is solved, and efficient heat utilization and system stability are achieved.
Patent Information
- Application Number
- CN202421699686.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-17
- Publication Date
- 2025-05-27
- Estimated Expiration
- 2034-07-17
AI Technical Summary
In the existing boiler economizers, waste heat cannot be fully recycled, resulting in the problem of energy waste.
A waste gas waste heat utilization system at the tail of the waste incinerator was designed. By setting a heat exchanger between the dust removal assembly and the chimney, the waste heat of the flue gas is recycled and utilized, and the heated hot water is used for heating of the dust removal assembly and ash conveying assembly to realize recycling.
It effectively reduces the smoke exhaust temperature, improves the thermal energy utilization rate, ensures the dry state of the ash delivery system, reduces the probability of ash accumulation, increases the stability of the system operation, saves factory electricity, and achieves the effect of reducing costs and increasing efficiency.
Smart Images
Figure CN222911664U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of waste incineration treatment, in particular to a waste incinerator tail gas waste heat utilization system. Background Art
[0002] At present, the boiler flue gas of domestic waste incineration power plants is basically discharged after heat exchange through various tube screens, economizers and air preheaters, through the reaction tower for acid removal, bag dust removal, and then discharged to the atmosphere through an induced draft fan. The flue gas temperature of the chimney is generally about 150°C. The flue gas discharged from the chimney carries a certain amount of heat and water vapor, and the water vapor remains in a gaseous state at a high temperature above 150°C. After these high-temperature flue gases are discharged into the air, they will quickly cool down, the temperature of the water vapor in the flue gas will decrease, and it will condense into white mist, also known as white smoke. At the same time, discharging 150°C flue gas into the atmosphere will cause great heat loss. From another perspective, the heat in the flue gas has great utilization value, promotes energy conservation and emission reduction, and can also reduce the generation of white smoke. However, the problem faced by heat exchange of this high-temperature flue gas is that once the flue gas temperature is lower than the acid dew point temperature of the flue gas, the acidic components (SO 2 ) in the flue gas will form sulfuric acid solution, which will corrode the heat exchanger and the flue. Therefore, materials that are not conducive to corrosion need to be selected in terms of material selection.
[0003] At present, there are many existing technologies for recovering waste heat from the tail gas of the boiler economizer, but the existing technologies related to waste incineration power plants are relatively few. First, the flue gas treatment system of waste incineration is quite different from that of traditional thermal power plants, and the flue gas components are more complex. Second, most of the patents for recovering waste heat from the tail flue gas are for heating feed water, and the existing design systems do not involve using the waste heat of the chimney. At the same time, in existing power plants, the heat preservation of each ash hopper and conveyor in the flue gas area is realized by electric tracing. First, the failure rate of electric tracing is relatively high and it consumes electricity. Second, the efficiency of electric tracing is not high, and the heat preservation effect on the ash hopper and ash conveying line is uneven. Content of the Utility Model
[0004] The technical problem to be solved by the utility model is: aiming at the problem that the waste heat of the existing boiler economizer fails to be fully recovered and utilized, resulting in obvious energy waste, a waste incinerator tail gas waste heat utilization system with a compact structure, high heat energy utilization rate and conducive to keeping the ash hopper and ash conveying line in a high-temperature and dry state is provided.
[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is:
[0006] A waste incinerator tail gas waste heat utilization system, comprising: a reaction tower, a dust removal assembly, a chimney, a heat exchanger, a water supply assembly and an ash conveying assembly. Heat exchange channels are provided on the outer sides of both the dust removal assembly and the ash conveying assembly; the reaction tower is connected to the waste incinerator through a flue gas pipeline, the side of the reaction tower is connected to the dust removal assembly, the dust removal assembly is respectively connected to the heat exchanger and the ash conveying assembly, the heat exchanger is connected to the chimney, the water supply assembly is connected to the water inlet end of the heat exchanger to provide normal-temperature industrial water, the water outlet end of the heat exchanger is respectively connected to the heat exchange channel inlets of the dust removal assembly and the ash conveying assembly, and the heat exchange channel outlets of the dust removal assembly and the ash conveying assembly are connected to the water supply assembly; the waste incineration flue gas enters the reaction tower for acid removal, the flue gas after acid removal enters the dust removal assembly, the ash generated in the dust removal assembly is collected into the ash conveying assembly, the flue gas discharged from the dust removal assembly enters the heat exchanger for heat exchange, the cooled flue gas enters the chimney and is discharged to the atmosphere, and the heated industrial water is transported to the heat exchange channels of the dust removal assembly and the ash conveying assembly to heat the dust removal assembly and the ash conveying assembly. The industrial water after heat exchange is then transported back to the water supply assembly for recycling.
[0007] As a further improvement of the present utility model, the smoke outlet of the dust removal assembly is connected to a smoke exhaust pipeline, an induced draft fan is provided on the smoke exhaust pipeline, a switching valve and a first bypass pipeline and a second bypass pipeline connected in parallel are provided at the end of the smoke exhaust pipeline. The first bypass pipeline is connected to the chimney, and the second bypass pipeline is connected to the heat exchanger; when the heat exchanger is under maintenance, the switching valve is switched to the first bypass pipeline, and the flue gas discharged from the dust removal assembly is discharged to the atmosphere through the chimney.
[0008] As a further improvement of the present utility model, a plurality of series-connected heat exchange pipes are arranged side by side inside the heat exchanger. The water inlet pipe of the heat exchange pipe is connected to the water supply assembly, and a water inlet regulating valve is provided in the water inlet pipe. A circulating water pump is provided between the water inlet pipe and the water supply assembly. The water outlet pipe of the heat exchange pipe is connected to the heat exchange channels of the dust removal assembly and the ash conveying assembly through a water outlet header pipe, and a water outlet regulating valve is provided on the water outlet pipe.
[0009] As a further improvement of the present utility model, a compressed air header pipe is provided at the top inside the heat exchanger. A plurality of compressed air branch pipes are connected in parallel to the compressed air header pipe. The compressed air branch pipes are located between adjacent heat exchange pipes, and a plurality of soot blowers are evenly distributed on the compressed air branch pipes; when compressed air is introduced into the compressed air header pipe, the soot blowers on the compressed air branch pipes rotate to sweep away the ash adhering to the outer sides of the heat exchange pipes.
[0010] As a further improvement of the present utility model, a third ash conveying line is provided at the bottom inside the heat exchanger for collecting the ash on the outer sides of the heat exchange pipes.
[0011] As a further improvement of the present utility model, the heat exchange pipes are made of fluoroplastic materials; a pressure release regulating valve is provided on the heat exchange pipes.
[0012] As a further improvement of the utility model, the water supply assembly includes an industrial water main pipe and a water tank. The industrial water main pipe is communicated with the water tank through a pipeline with a water tank inlet regulating valve to inject normal-temperature industrial water into the water tank. The water tank is communicated with the inlet pipeline of the heat exchange pipeline to enable the normal-temperature industrial water to enter the interior of the heat exchanger. The water tank is communicated with the heat exchange flow channels of the dust removal assembly and the ash conveying assembly through a return water main pipe to realize industrial water circulation.
[0013] As a further improvement of the utility model, a liquid level gauge and a thermometer are provided on the side of the water tank. The water tank is connected to the hot water pipe network through a pipeline with a water pump; when the liquid level or temperature in the water tank is higher than the preset value, the water pump pumps the water in the water tank to the hot water pipe network.
[0014] As a further improvement of the utility model, the dust removal assembly includes a bag filter and a hopper. The air inlet of the bag filter is communicated with the side of the reaction tower, the air outlet of the bag filter is communicated with the smoke exhaust pipeline, and a plurality of hoppers are evenly distributed at the bottom of the bag filter. The hoppers are communicated with the ash conveying assembly, and a heat exchange flow channel is provided outside the hoppers.
[0015] As a further improvement of the utility model, the ash conveying assembly includes a first ash conveying line, a second ash conveying line, an ash silo and a common ash conveying line; the first ash conveying line is arranged at the bottom of the reaction tower to collect and convey the ash falling in the reaction tower, the second ash conveying line is communicated with the hopper to convey the ash falling in the bag filter, the first ash conveying line and the second ash conveying line are both communicated with the common ash conveying line, and the common ash conveying line is communicated with the ash silo; heat exchange flow channels are provided outside the first ash conveying line, the second ash conveying line and the common ash conveying line.
[0016] Compared with the prior art, the advantages of the utility model are as follows:
[0017] In the waste incinerator tail gas waste heat utilization system of the utility model, a heat exchanger is arranged between the dust removal assembly and the chimney. The water outlet ends of the heat exchanger are respectively connected to the inlets of the heat exchange flow channels of the dust removal assembly and the ash conveying assembly, and the outlets of the heat exchange flow channels of the dust removal assembly and the ash conveying assembly are connected to the water supply assembly. The waste heat of the flue gas discharged from the incinerator is recovered and utilized through a heat exchange device, effectively reducing the smoke exhaust temperature. At the same time, the heat exchanger has functions such as corrosion resistance and high heat exchange efficiency, and the heated hot water is used as a heat source for the dust removal assembly and the ash conveying assembly, ensuring the drying effect of the ash conveying system, reducing the probability of ash accumulation in the ash conveying system, increasing the stability of system operation, replacing the electric tracing designed for the original ash conveying system, and the waste heat recovery system of the utility model also has an adjustment function to ensure the temperature stability of hot water heating, and finally achieves an effect of cost reduction and efficiency increase, both utilizing the waste heat of the flue gas and saving the plant electricity, and well solving the problem of obvious energy waste caused by the failure to fully recover and utilize the waste heat in the traditional boiler economizer. Description of the Drawings
[0018] Figure 1 This is a schematic structural principle diagram of the waste heat utilization system for the tail gas of the waste incinerator in a specific embodiment of the present utility model;
[0019] Figure 2 This is a schematic operating principle diagram of the internal structure of the heat exchanger in a specific embodiment of the present utility model;
[0020] Figure 3 This is a schematic diagram of the water circulation heating effect in a specific embodiment of the present utility model;
[0021] Legend: 1. First ash conveying line; 2. Reaction tower; 3. Flue gas pipeline; 4. Bag filter; 5. Second ash conveying line; 6. Ash hopper; 7. Induced draft fan; 8. Switching valve; 9. Exhaust pipe; 91. First bypass pipe; 92. Second bypass pipe; 10. Chimney; 11. Heat exchanger; 12. Industrial water main pipe; 13. Water tank; 14. Liquid level gauge; 15. Ash silo; 16. Common ash conveying line; 17. Hot water supply pipe; 18. Hot water return pipe; 19. Circulation water pump; 20. Pressure relief regulating valve; 21. Compressed air main pipe; 211. Compressed air branch pipe; 22. Water inlet pipe; 23. Water inlet regulating valve; 24. Third ash conveying line; 25. Water outlet pipe; 26. Water outlet regulating valve; 27. Soot blower; 28. Heat exchange pipe; 29. Total water outlet regulating valve; 30. Water outlet main pipe; 31. Return water main pipe; 32. Pressure gauge; 33. Manual isolation door; 34. Hot water pipe network; 35. Thermometer; 36. Water tank water inlet regulating valve; 37. Extraction pump. Detailed Embodiments
[0022] The present utility model will be further described below in conjunction with the accompanying drawings of the specification and specific preferred embodiments, but this does not limit the protection scope of the present utility model.
[0023] In the description of the present utility model, it should be understood that the orientation or positional relationships indicated by the terms "side", "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present utility model.
[0024] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, "a plurality of" means two or more, unless otherwise specifically defined.
[0025] Embodiment
[0026] As Figures 1 to 3 shown, the waste incinerator tail gas waste heat utilization system of the present utility model includes: a reaction tower 2, a dust removal assembly, a chimney 10, a heat exchanger 11, a water supply assembly, and an ash conveying assembly. Heat exchange channels are provided outside both the dust removal assembly and the ash conveying assembly. The reaction tower 2 is connected to the waste incinerator through a flue gas pipeline 3. The side of the reaction tower 2 is connected to the dust removal assembly. The dust removal assembly is respectively connected to the heat exchanger 11 and the ash conveying assembly. The heat exchanger 11 is connected to the chimney 10. The water supply assembly is connected to the water inlet end of the heat exchanger 11 to provide normal-temperature industrial water. The water outlet end of the heat exchanger 11 is respectively connected to the heat exchange channel inlets of the dust removal assembly and the ash conveying assembly. The heat exchange channel outlets of the dust removal assembly and the ash conveying assembly are connected to the water supply assembly. During operation, the waste incineration flue gas enters the reaction tower 2 to carry out an acid removal reaction with lime slurry. The flue gas after acid removal enters the dust removal assembly. The ash generated in the dust removal assembly is collected in the ash conveying assembly. The flue gas discharged from the dust removal assembly enters the heat exchanger 11 for heat exchange. The cooled flue gas enters the chimney 10 and is then discharged to the atmosphere. The heated industrial water is transported to the heat exchange channels of the dust removal assembly and the ash conveying assembly to heat the dust removal assembly and the ash conveying assembly. The industrial water after heat exchange is then transported back to the water supply assembly to achieve recycling.
[0027] In this embodiment, by providing a heat exchanger 11 between the dust removal assembly and the chimney 10, the water outlet end of the heat exchanger 11 is respectively connected to the heat exchange channel inlets of the dust removal assembly and the ash conveying assembly, and the heat exchange channel outlets of the dust removal assembly and the ash conveying assembly are connected to the water supply assembly. The waste heat of the flue gas discharged from the incinerator is recovered and utilized through a heat exchange device, effectively reducing the flue gas discharge temperature. At the same time, this heat exchanger has functions such as corrosion resistance and high heat exchange efficiency. Moreover, the heated hot water is used as a heat source for the dust removal assembly and the ash conveying assembly, ensuring the drying effect of the ash conveying system, reducing the probability of ash accumulation in the ash conveying system, increasing the stability of the system operation, replacing the electric tracing originally designed for the ash conveying system. Moreover, the waste heat recovery system of the embodiment also has an adjustment function to ensure the temperature stability of the hot water heating, ultimately achieving an effect of cost reduction and efficiency increase, both utilizing the waste heat of the flue gas and saving the plant electricity, and well solving the problem of obvious energy waste caused by the failure to fully recover and utilize the waste heat in the economizer of the traditional boiler.
[0028] As Figure 1As shown in the figure, the smoke exhaust port of the dust removal component is connected to the smoke exhaust pipe 9. An induced draft fan 7 is provided on the smoke exhaust pipe 9. The induced draft fan 7 is used to divert the flue gas in the dust removal component into the smoke exhaust pipe 9. A switching valve 8, a first bypass pipe 91 and a second bypass pipe 92 in parallel are provided at the end of the smoke exhaust pipe 9. The first bypass pipe 91 is directly connected to the chimney 10, and the second bypass pipe 92 is connected to the heat exchanger 11. During normal operation, the flue gas enters the heat exchanger 11 through the second bypass pipe 92 and then enters the chimney 10. When the heat exchanger 11 is under maintenance, the switching valve 8 is switched to the first bypass pipe 91, and the flue gas discharged from the dust removal component is discharged to the atmosphere through the chimney 10.
[0029] As Figure 2 shown in the figure, a plurality of heat exchange pipes 28 connected in series are arranged side by side inside the heat exchanger 11. The water inlet pipe 22 of the heat exchange pipe 28 is connected to the water supply component, and a water inlet regulating valve 23 is provided in the water inlet pipe 22. A circulating water pump 19 is provided between the water inlet pipe 22 and the water supply component. The water outlet pipe 25 of the heat exchange pipe 28 is connected to the heat exchange flow channels of the dust removal component and the ash conveying component through a water outlet main pipe 30, and a water outlet regulating valve 26 is provided on the water outlet pipe 25.
[0030] As Figure 2 shown in the figure, a compressed air main pipe 21 is provided at the inner top of the heat exchanger 11. A plurality of compressed air branch pipes 211 are connected in parallel to the compressed air main pipe 21. The compressed air branch pipes 211 are located between adjacent heat exchange pipes 28, and a plurality of soot blowers 27 are evenly distributed on the compressed air branch pipes 211. When compressed air is introduced into the compressed air main pipe 21, the soot blowers 27 on the compressed air branch pipes 211 rotate to sweep away the ash adhering to the outer side of the heat exchange pipe 28. Correspondingly, a third ash conveying line 24 is provided at the inner bottom of the heat exchanger 11 to collect the ash on the outer side of the heat exchange pipe 28.
[0031] In this embodiment, the heat exchange pipe 28 is made of fluoroplastic material to improve the corrosion resistance of the heat exchanger 11. At the same time, a pressure relief regulating valve 20 is provided on the heat exchange pipe 28 to timely discharge the pressure in the heat exchange pipe 28 and improve the safety of the heat exchanger 11.
[0032] As Figure 2As shown in the figure, the flue gas at about 150°C enters from the left side of the heat exchanger 11. Inside the heat exchanger 11 are heat exchange pipes 28 made of fluoroplastics. The flowing medium inside the heat exchange pipes 28 is normal temperature water at 0.5 mpa and about 20°C. Through the principle of convective heat transfer, the 150°C flue gas exchanges heat with the 20°C water. The temperature of the flue gas drops to about 80°C, and the water temperature rises to about 80°C. The flue gas after heat exchange is on the right side of the heat exchanger 11 and is discharged to the atmosphere through the chimney 10. The normal temperature water flows into the water inlet pipe 22. The water flow rate is adjusted by the water inlet regulating valve 23. After heat exchange in the heat exchange pipes 28, it flows out through the water outlet pipe 25. The water flow rate can be adjusted by the water outlet regulating valve 26. Or, when the inside of the heat exchanger 11 is under maintenance, the water inlet regulating valve 23 and the water outlet regulating valve 26 are used as isolation doors. The hot water coming out of the heat exchanger 11 acts on the users to be heated.
[0033] If the pressure inside the heat exchange pipes 28 is too high, it can be released through the pressure regulating relief valve 20 to ensure the safety of the fluoroplastics heat exchanger pipes 28 inside the heat exchanger 11 (generally, the pressure is lower than 1 mpa). At the same time, as the flue gas passes through the inside of the heat exchanger 11, more ash will accumulate on the outside of the heat exchange pipes 28. The heat exchanger 11 will be regularly cleaned. Specifically, compressed air at about 0.6 mpa is input through the compressed air main pipe 21. The compressed air passes through the soot blower 27 to blow the ash outside the heat exchange pipes 28. The blown ash is collected through the ash conveying line 24 and then sent to the ash bunker 15. The heat exchange pipes 28 inside the heat exchanger 11 are arranged in a serpentine shape, and a set of soot blowers 27 is arranged between every two pipes, ensuring the cleaning effect of the heat exchanger 11 by using the soot blowing system.
[0034] As Figure 1 shown, the water supply assembly includes the industrial water main pipe 12 and the water tank 13. The industrial water main pipe 12 is connected to the water tank 13 through a pipe with a water tank inlet regulating valve 36 to inject normal temperature industrial water into the water tank 13. The water tank 13 is connected to the water inlet pipe 22 of the heat exchange pipes 28 to allow the normal temperature industrial water to enter the inside of the heat exchanger 11. The water tank 13 is connected to the heat exchange flow channels of the dust removal assembly and the ash conveying assembly through the return water main pipe 31 to realize industrial water circulation.
[0035] As Figure 3 shown, a liquid level gauge 14 and a thermometer 35 are provided on the side of the water tank 13. The water tank 13 is connected to the hot water pipe network 34 through a pipe with a water pump 37. When the liquid level or temperature in the water tank 13 is higher than the preset value, the water pump 37 pumps the water in the water tank 13 to the hot water pipe network 34.
[0036] In this embodiment, normal-temperature industrial water replenishes the water tank 13 through the industrial water main pipe 12 to the high water level, and then is pressurized by the circulating water pump 19 to ensure that the pressure is stable at about 0.5 mpa; the circulating water pump 19 can be adjusted in frequency. The total outlet regulating valve 29 can adjust the amount of water in the pipeline. A manual isolation valve 33 is also provided in the pipeline to isolate the equipment when some equipment needs to be repaired. As Figure 3 shown, in this embodiment, manual isolation valves 33 are provided in multiple pipelines as partition doors during equipment maintenance. After ensuring the stability of pressure and flow, the industrial water enters the heat exchanger 11 for heat exchange. The water after heat exchange enters the outlet water main pipe 30, and the pressure is displayed through the pressure gauge 32 to ensure that the pressure is within the qualified standard. If the pressure is unqualified, it will be adjusted by changing the frequency of the circulating water pump 19. The pressurized hot water is distributed through the hot water supply pipe 17 to the dust removal assembly and the ash conveying assembly for heat exchange. The water after heat exchange is collected into the return water main pipe 31 through the hot water return pipe 18 and finally returns to the water tank 13 for recycling and heating again, which is equivalent to a process of heat absorption and consumption. A pressure gauge 32 is also provided in the return water main pipe 31 to monitor the pressure water change in real time and improve the safety of system operation.
[0037] When the water temperature is too high or the water volume is too large, such as when the thermometer 35 shows that the temperature is higher than 50 °C, the water pump 37 will start to pump the high-temperature water and the excess water to the hot water pipe network 34. When the water volume does not reach the preset standard, water will be replenished through the water tank inlet regulating valve 36 to prevent waste of excess water, and at the same time ensure the heat exchange effect of the heat exchanger 11 to achieve the effect of reducing the flue gas temperature. The liquid level gauge 14, the circulating water pump 19, the total outlet regulating valve 29, the pressure gauge 32, the thermometer 35, the water tank inlet regulating valve 36 and the water pump 37 are uniformly incorporated into the power plant DCS control system to achieve the effect of automatic control.
[0038] As Figure 1 shown, the dust removal assembly includes a bag filter 4 and a hopper 6. The air inlet of the bag filter 4 is connected to the side of the reaction tower 2, the air outlet of the bag filter 4 is connected to the smoke exhaust pipe 9, and a plurality of hoppers 6 are evenly distributed at the bottom of the bag filter 4. The hopper 6 is connected to the ash conveying assembly, and a heat exchange flow channel is provided outside the hopper 6.
[0039] As Figure 1 shown, the ash conveying assembly includes a first ash conveying line 1, a second ash conveying line 5, an ash bin 15 and a common ash conveying line 16. The first ash conveying line 1 is arranged at the bottom of the reaction tower 2 to collect and convey the ash falling in the reaction tower 2. The second ash conveying line 5 is connected to the hopper 6 to convey the ash falling in the bag filter 4. The first ash conveying line 1 and the second ash conveying line 5 are both connected to the common ash conveying line 16, and the common ash conveying line 16 is connected to the ash bin 15. Heat exchange flow channels are provided outside the first ash conveying line 1, the second ash conveying line 5 and the common ash conveying line 16.
[0040] In this embodiment, the first ash conveying line 1, the second ash conveying line 5, the ash hopper 6, and the common ash conveying line 16 all adopt a double-layer layout structure. Hot water flows through the middle for heating, and the material of 20G is used. Anticorrosive paint is applied to ensure that the equipment is not easily corroded, to ensure the stability of the equipment and at the same time can uniformly heat the fly ash inside.
[0041] In this embodiment, the flow process of the flue gas and the formation process of the ash are as follows: The boiler flue gas enters the reaction tower 2 through the flue gas pipeline 3 for the semi-dry desulfurization process. The compounds (CaSO4, CaCl2) formed by the reaction of the acidic gas in the flue gas with the lime slurry enter the first ash conveying line 1 for collection, and then enter the common ash conveying line 16 for overall collection, and finally enter the ash silo 15 for storage. The temperature of the flue gas after desulfurization drops from about 200°C to about 150°C, enters the bag filter 4 for filtration. The ash blown by compressed air flows from the ash hopper 6 into the second ash conveying line 5 for collection, then enters the common ash conveying line 16, and finally reaches the ash silo 15 for storage. The temperature of the filtered flue gas remains basically unchanged and meets the national emission standards. The flue gas is discharged to the exhaust pipe 9 through the induced draft fan 7. The exhaust pipe 9 has two branch pipes, and the on-off of the pipe is adjusted by the switching valve 8. During normal operation, the switching valve 8 is switched to the second bypass pipe 92, and the flue gas at about 150°C exchanges heat with the normal temperature water through the heat exchanger 11. The flue gas after heat exchange is discharged to the atmosphere through the chimney 10. When the heat exchanger 11 is under maintenance, the switching valve 8 is switched to the first bypass pipe 91, and the flue gas is directly discharged to the atmosphere through the chimney 10.
[0042] In this embodiment, the flow process of the heat exchange medium water is as follows: Water replenishes the water tank 13 through the industrial water main pipe 12 and operates at a high water level. The water is pressurized to about 0.5 mpa by the variable-frequency circulating water pump 19 and is transported into the heat exchanger 11 to exchange heat with the flue gas. The water after heat exchange is transported to the first ash conveying line 1, the second ash conveying line 5, the ash hopper 6, and the common ash conveying line 16 through the outlet water main pipe 30; these four heating devices all adopt a double-layer layout, with a space for hot water left in the middle. The temperature is transferred to the inner wall through the water temperature, so that the temperature of the inner wall is uniform, and thus the temperature of the ash hopper is uniform. When discharging ash, there will be no ash accumulation or ash caking due to too low temperature. The water after heat exchange returns to the water tank 13 through the return water main pipe 31. The water tank 13 can adjust the water volume and water temperature according to the monitoring data of the liquid level gauge 14 and the thermometer 35. If the return water temperature is relatively high, the water is transported to the hot water pipe network 34 of the air conditioner for utilization, and then the normal temperature water of the industrial pipe network is replenished. If the water temperature is relatively low, the pressure of the circulating water pump 19 is reduced, and at the same time, the flue gas flow rate of the heat exchanger 11 is increased to increase the water temperature.
[0043] In this embodiment, the heat exchanger 11 made of fluoroplastics has the characteristics of high corrosion resistance, and has good heat exchange efficiency even when the heat exchange area is large. It can heat the flue gas at 150 °C into water at about 80 °C, and the flue gas temperature drops to about 80 °C and is discharged into the atmosphere without generating white steam. This heat exchanger 11 utilizes the heat of the unused high-temperature flue gas, achieving the effect of reducing the exhaust gas loss and increasing the efficiency of the boiler. At the same time, the heated water is used for the hopper 6 of the bag filter 4 and the ash conveying line, the ash conveying lines of the reaction tower 2, the common ash conveying line 16 and other equipment that need to be heated. The heating effect of the equipment is more uniform, greatly reducing the possibility of ash accumulation. At the same time, no additional power consumption is required, greatly reducing the electricity cost and achieving the effect of cost reduction and efficiency increase.
[0044] The above is only the preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for those of ordinary skill in the art in this technical field, several improvements and refinements made without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.
Claims
1. A waste incinerator tail flue gas waste heat utilization system, characterized in that: include: A reaction tower (2), a dust removal component, a chimney (10), a heat exchanger (11), a water supply component and an ash conveying component, wherein heat exchange channels are arranged on the outer sides of the dust removal component and the ash conveying component; the reaction tower (2) is connected to the waste incinerator through a flue gas pipeline (3); the side of the reaction tower (2) is connected to the dust removal component; the dust removal component is respectively connected to the heat exchanger (11) and the ash conveying component; the heat exchanger (11) is connected to the chimney (10); the water supply component is connected to the water inlet of the heat exchanger (11) to provide industrial water at room temperature; the water outlet of the heat exchanger (11) is respectively connected to the heat exchanger of the dust removal component and the ash conveying component; The hot runner inlet, the heat exchange runner outlets of the dust removal component and the ash conveying component are connected to the water supply component; the waste incineration flue gas enters the reaction tower (2) for deacidification, the flue gas after deacidification enters the dust removal component, the ash generated in the dust removal component is collected in the ash conveying component, the flue gas discharged from the dust removal component enters the heat exchanger (11) for heat exchange, the flue gas after cooling enters the chimney (10) and is discharged to the atmosphere, the heated industrial water is transported to the heat exchange runners of the dust removal component and the ash conveying component to heat the dust removal component and the ash conveying component, and the industrial water after heat exchange is then transported to the water supply component for recycling.
2. The waste incinerator tail flue gas waste heat utilization system according to claim 1 is characterized in that: The smoke exhaust port of the dust removal component is connected to a smoke exhaust pipe (9), an induced draft fan (7) is provided on the smoke exhaust pipe (9), and a switching valve (8) and a first bypass pipe (91) and a second bypass pipe (92) connected in parallel are provided at the end of the smoke exhaust pipe (9), the first bypass pipe (91) is connected to the chimney (10), and the second bypass pipe (92) is connected to the heat exchanger (11); when the heat exchanger (11) is under maintenance, the switching valve (8) is switched to the first bypass pipe (91), and the smoke exhausted by the dust removal component is discharged into the atmosphere through the chimney (10).
3. The waste incinerator tail flue gas waste heat utilization system according to claim 2 is characterized in that: A plurality of heat exchange pipes (28) connected in series are arranged side by side inside the heat exchanger (11); a water inlet pipe (22) of the heat exchange pipe (28) is connected to a water supply component, and a water inlet regulating valve (23) is arranged in the water inlet pipe (22); a circulating water pump (19) is arranged between the water inlet pipe (22) and the water supply component; a water outlet pipe (25) of the heat exchange pipe (28) is connected to the heat exchange flow passages of the dust removal component and the ash conveying component through a water outlet mother pipe (30), and a water outlet regulating valve (26) is arranged on the water outlet pipe (25).
4. The waste incinerator tail flue gas waste heat utilization system according to claim 3 is characterized in that: A compressed air main pipe (21) is provided at the top of the inner side of the heat exchanger (11), and a plurality of compressed air branch pipes (211) are connected in parallel to the compressed air main pipe (21), the compressed air branch pipes (211) are located between adjacent heat exchange pipes (28), and a plurality of soot blowers (27) are evenly distributed on the compressed air branch pipes (211); when compressed air is introduced into the compressed air main pipe (21), the soot blowers (27) on the compressed air branch pipes (211) rotate to sweep away the dust adhering to the outer side of the heat exchange pipe (28).
5. The waste incinerator tail flue gas waste heat utilization system according to claim 4 is characterized in that: A third ash conveying line (24) is provided at the inner bottom of the heat exchanger (11) for collecting ash falling from the outside of the heat exchange pipe (28).
6. The waste incinerator tail flue gas waste heat utilization system according to claim 4, characterized in that: The heat exchange pipeline (28) is made of fluoroplastic material; a pressure release regulating valve (20) is provided on the heat exchange pipeline (28).
7. The waste incinerator tail flue gas waste heat utilization system according to claim 3, characterized in that: The water supply component comprises an industrial water pipe (12) and a water tank (13); the industrial water pipe (12) and the water tank (13) are connected via a pipeline with a water tank water inlet regulating gate (36) to inject industrial water at room temperature into the water tank (13); the water tank (13) is connected to the water inlet pipeline (22) of the heat exchange pipeline (28) to allow industrial water at room temperature to enter the interior of the heat exchanger (11); the water tank (13) is connected to the heat exchange flow channels of the dust removal component and the ash conveying component via the water return pipe (31) to achieve industrial water circulation.
8. The waste incinerator tail flue gas waste heat utilization system according to claim 7, characterized in that: A liquid level meter (14) and a thermometer (35) are provided on the side of the water tank (13), and the water tank (13) is connected to a hot water pipe network (34) via a pipeline with a water pump (37); when the liquid level or temperature in the water tank (13) is higher than a preset value, the water pump (37) pumps the water in the water tank (13) to the hot water pipe network (34).
9. The waste incinerator tail flue gas waste heat utilization system according to any one of claims 2 to 8, characterized in that: The dust removal component comprises a bag filter (4) and an ash hopper (6); the air inlet of the bag filter (4) is connected to the side of the reaction tower (2); the air outlet of the bag filter (4) is connected to the smoke exhaust duct (9); a plurality of ash hoppers (6) are evenly distributed at the bottom of the bag filter (4); the ash hoppers (6) are connected to the ash conveying component, and a heat exchange flow channel is provided on the outside of the ash hopper (6).
10. The waste incinerator tail flue gas waste heat utilization system according to claim 9, characterized in that: The ash conveying assembly comprises a first ash conveying line (1), a second ash conveying line (5), an ash bin (15) and a common ash conveying line (16); the first ash conveying line (1) is arranged at the bottom of the reaction tower (2) for collecting and conveying fallen ash in the reaction tower (2); the second ash conveying line (5) is connected to the ash hopper (6) for conveying fallen ash in the bag filter (4); the first ash conveying line (1) and the second ash conveying line (5) are both connected to the common ash conveying line (16), and the common ash conveying line (16) is connected to the ash bin (15); the outer sides of the first ash conveying line (1), the second ash conveying line (5) and the common ash conveying line (16) are all provided with heat exchange channels.