Fly ash in-situ treatment system of waste incineration power plant

Abstract

The utility model discloses a fly ash in-situ treatment system of a waste incineration power plant. The fly ash in-situ treatment system comprises a low-temperature pyrolysis unit, a washing MVR (mechanical vapor recompression) salt separation unit and an artificial aggregate unit, the low-temperature pyrolysis unit comprises a low-temperature pyrolysis reactor, a cooling section and a gas-gas heat exchanger, the low-temperature pyrolysis reactor is connected with the cooling section, the cooling section is connected with the washing MVR salt separation unit, and the low-temperature pyrolysis unit completes pyrolysis treatment of input waste incineration fly ash; the washing MVR salt separation unit comprises a washing module, a filter pressing module, a dosing sedimentation tank, an MVR evaporator, a crystal slurry tank, a thickener and a centrifugal machine which are connected in sequence, and a salt solution from the filter pressing module passes through the dosing sedimentation tank, the MVR evaporator, the crystal slurry tank, the thickener and the centrifugal machine to obtain calcium chloride, sodium chloride and potassium chloride products; the artificial aggregate unit comprises a dryer, a fly ash bin, a mixing granulator and screening equipment which are connected in sequence, and is used for completing granulation treatment on input materials.

Description

Technical Field

[0001] This utility model belongs to the field of hazardous waste disposal technology, and in particular relates to an in-situ fly ash treatment system for waste incineration power plants. Background Technology

[0002] Municipal solid waste incineration power plants produce fly ash, which accounts for about 3-5% of the total mass of waste. Fly ash is a typical hazardous waste, mainly because it contains high concentrations of heavy metals, dioxins, furans, and polycyclic aromatic hydrocarbons, which are difficult to degrade naturally. If not handled properly, it can spread through soil, water, air, and the food chain, causing serious harm to the human body.

[0003] Commonly used fly ash solidification and landfill technologies are difficult to use in new projects due to the gradual implementation of "zero landfill" of fly ash from waste incineration and the insufficient capacity of existing fly ash landfills. The high-temperature environment of cement kiln co-processing will drive the volatilization of heavy metals in fly ash, exacerbating air pollution. High-temperature melting or high-temperature sintering technologies for fly ash are limited in their large-scale engineering application due to excessive energy consumption.

[0004] The novel low-temperature pyrolysis of fly ash is a technology that slowly heats the fly ash from waste incineration at 350-500℃, which can effectively degrade organic pollutants in fly ash. However, due to problems such as (1) centralized pyrolysis treatment requires the fly ash to be transferred from various waste incineration power plants, which poses a risk of leakage during hazardous waste transfer and has high transportation costs; (2) fly ash absorbs water during transportation, and a drying section needs to be set up during the pyrolysis process. In addition, the use of electric heating results in high energy consumption; (3) pyrolysis exhaust gas is inconvenient to monitor; and (4) there is a lack of resource utilization scenarios after fly ash treatment, the low-temperature pyrolysis technology of fly ash has not yet been applied on a large scale. Utility Model Content

[0005] The purpose of this utility model is to overcome the problems of the prior art and disclose an in-situ fly ash treatment system for waste incineration power plants. This application makes full use of the existing resources of waste incineration power plants to achieve low-cost, distributed in-situ treatment of waste incineration fly ash, while producing aggregates and industrial salt with certain value.

[0006] The objective of this utility model is achieved through the following technical solution:

[0007] A fly ash in-situ treatment system for a waste incineration power plant, the fly ash in-situ treatment system comprising: a low-temperature pyrolysis unit, a water washing MVR salt separation unit, and an artificial aggregate unit;

[0008] The low-temperature pyrolysis unit includes a low-temperature pyrolysis reactor, a cooling section, and a gas-to-gas heat exchanger. The low-temperature pyrolysis reactor and the cooling section are connected to each other, and the cooling section is connected to the water washing MVR salt separation unit. The low-temperature pyrolysis unit completes the pyrolysis treatment of the input waste incineration fly ash.

[0009] Furthermore, the gas-to-gas heat exchanger is connected to the low-temperature pyrolysis reactor, and the gas-to-gas heat exchanger provides heat source air to the low-temperature pyrolysis reactor. The gas-to-gas heat exchanger is also connected to the flue gas system of the waste incineration power plant, and the flue gas system provides heat source gas to the gas-to-gas heat exchanger.

[0010] The cooling section is also connected to the ammonia system of the waste incineration power plant. The air from the ammonia system is transported to the cooling section to be preheated and then flows to the low-temperature pyrolysis reactor to carry out the corresponding pyrolysis reaction.

[0011] The water-washing MVR salt separation unit includes a water washing module, a filter press module, a dosing sedimentation tank, an MVR evaporator, a crystallizer, a thickener, and a centrifuge connected in sequence. The salt solution from the filter press module passes through the dosing sedimentation tank, the MVR evaporator, the crystallizer, the thickener, and the centrifuge to obtain calcium chloride, sodium chloride, and potassium chloride products.

[0012] The water washing MVR salt separation unit also includes a mixing condensate tank. The dosing sedimentation tank and the MVR evaporator are connected to the mixing condensate tank via pipelines. The mixing condensate tank receives the condensate from the dosing sedimentation tank and the MVR evaporator. Thus, the water washing MVR salt separation unit completes the water washing and salt separation treatment of the material input from the low-temperature pyrolysis unit. The filter press module is also connected to the artificial aggregate unit.

[0013] The artificial aggregate unit includes a dryer, fly ash silo, mixing granulator and screening equipment connected in sequence, which are used to complete the granulation process of the input materials.

[0014] According to a preferred embodiment, the pyrolysis reactor and the gas-to-gas heat exchanger are roller devices with indirect heat exchange.

[0015] According to a preferred embodiment, the low-temperature pyrolysis reactor is further provided with a pipeline connected to the power plant flue gas system. The heat source air received by the low-temperature pyrolysis reactor flows through the pipeline to the power plant flue gas system after passing through the low-temperature pyrolysis reactor, and is input into the furnace as combustion air.

[0016] According to a preferred embodiment, the cooling section is also connected to the power plant circulating water system of the waste incineration power plant, receiving the cooling medium input from the power plant circulating water system to complete the cooling treatment of the materials in the cooling section, and transporting the corresponding cooling medium back to the power plant circulating water system through pipelines.

[0017] According to a preferred embodiment, the washing module is provided with three-stage washing tanks, namely a primary washing tank, a secondary washing tank and a tertiary washing tank, and the filter press module is provided with three-stage filter presses, namely a primary filter press, a secondary filter press and a tertiary filter press.

[0018] According to a preferred embodiment, the primary washing tank is connected to the primary filter press, the primary filter press is connected to the secondary water tank, the secondary water tank is connected to the secondary filter press, the secondary filter press is connected to the tertiary water tank, the tertiary water tank is connected to the tertiary filter press, and the tertiary filter press is connected to both a chemical dosing sedimentation tank and a dryer. The liquid produced by filtration flows into the chemical dosing sedimentation tank, and the solid produced by filtration is sent to the dryer.

[0019] According to a preferred embodiment, the MVR evaporator is connected to the waste heat boiler system of the waste incineration power plant, and the heat source for the MVR evaporator is provided by the waste heat boiler system of the power plant.

[0020] The aforementioned main solution of this utility model and its various further alternative solutions can be freely combined to form multiple solutions, all of which are solutions that can be adopted by this utility model and for which protection is sought. Those skilled in the art, after understanding the solution of this utility model, will realize, based on existing technology and common knowledge, that there are many combinations, all of which are technical solutions to be protected by this utility model; therefore, they are not exhaustively listed here.

[0021] The beneficial effects of this utility model are:

[0022] The in-situ fly ash treatment system of the waste incineration power plant proposed in this application realizes the in-situ distributed treatment of fly ash from waste incineration. The in-situ fly ash treatment system of this application is coupled with the existing flue gas system, circulating water system, nitrogen system and waste heat boiler system of the waste incineration power plant, realizing efficient and low-cost fly ash treatment, with good economic and environmental benefits.

[0023] The air-to-air heat exchanger in the fly ash in-situ treatment system of this application utilizes the high-temperature flue gas from the existing flue gas system of the waste incineration power plant to heat the air. The hot air is used to achieve safe and stable pyrolysis of fly ash, and the hot air is returned to the waste incinerator to achieve cascaded utilization of energy and reduce energy consumption.

[0024] In this application, the pyrolysis exhaust gas in the fly ash in-situ treatment system is returned to the existing flue gas system of the waste incineration power plant for purification through the existing flue gas treatment system, resulting in lower cost and better effect.

[0025] The fly ash in-situ treatment system of this application detoxifies dioxin-like organic compounds through a low-temperature pyrolysis unit, separates high-value salts from fly ash through a water washing MVR salt separation unit, and achieves harmless resource utilization of fly ash treatment products through an artificial aggregate unit. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the system structure of the fly ash in-situ treatment system for waste incineration power plants according to this utility model. Detailed Implementation

[0027] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0028] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0029] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0030] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0031] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0032] Furthermore, it should be noted that unless otherwise specified, the specific structures, connections, positions, power sources, etc. involved in this utility model are all things that a person skilled in the art can know without creative effort based on the prior art.

[0033] refer to Figure 1 As shown, this application discloses an in-situ fly ash treatment system for a waste incineration power plant. The in-situ fly ash treatment system mainly includes three units: a low-temperature pyrolysis unit 1, a water washing MVR salt separation unit 2, and an artificial aggregate unit 3, as well as the waste incineration power plant flue gas system 41, power plant circulating water system 42, power plant nitrogen system 43, and waste heat boiler system 44.

[0034] The low-temperature pyrolysis unit 1 includes a low-temperature pyrolysis reactor 11, a cooling section 12, and a gas-to-gas heat exchanger 13 that provides a heat source, which are connected in sequence.

[0035] The water washing MVR salt separation unit 2 includes a water washing module 21, a filter press module 22, a chemical dosing sedimentation tank 23, an MVR evaporator 24, a crystal slurry tank 25, a thickener 26, a centrifuge 27, and a mixed condensate tank 28 for receiving condensate from the chemical dosing sedimentation tank 23 and the MVR evaporator 24, which are connected in sequence.

[0036] The artificial aggregate unit 3 includes a dryer 31, a fly ash silo 32, a mixing granulator 33 and a screening device 34 connected in sequence;

[0037] The fly ash from the waste incineration power plant is directly fed into the low-temperature pyrolysis reactor 11 in the on-site low-temperature pyrolysis unit 1. The heat source of the low-temperature pyrolysis reactor 11 comes from the hot air in the gas-to-gas heat exchanger 13, and the heat source of the gas-to-gas heat exchanger 13 comes from the high-temperature flue gas in the power plant flue gas system 41.

[0038] Preferably, the pyrolysis reactor 11 is a roller device with indirect heat exchange, which has high heat transfer efficiency and low failure rate; the gas-to-gas heat exchanger 13 is an indirect heat exchange device that generates hot air that meets process requirements through high-temperature flue gas.

[0039] Furthermore, the heat source air of the pyrolysis reactor 11 will be returned to the power plant flue gas system 41 and enter the furnace as combustion air, thereby improving energy utilization efficiency.

[0040] Furthermore, the fly ash inlet of the cooling section 12 is directly connected to the fly ash outlet of the pyrolysis reactor 11. After being detoxified by low-temperature pyrolysis, the fly ash enters the cooling section 12 for rapid cooling to prevent the resynthesis of dioxins.

[0041] Preferably, the cooling water for the cooling section 12 comes from the power plant circulating water system 42, and the cooled water is also sent to the power plant circulating water system 42 for treatment.

[0042] Furthermore, the nitrogen from the power plant's nitrogen system 43 is first preheated by the cooling section 12 before entering the low-temperature pyrolysis reactor 11 to ensure the normal progress of the pyrolysis reaction.

[0043] Preferably, the detoxified fly ash enters the water-washing MVR salt separation unit 2, where the salts are separated by the water washing module 21 and the pressure filter module 22.

[0044] Furthermore, the water washing module 21 and the pressure filtration module 22 improve the salt separation rate through repeated water washing and pressure filtration.

[0045] Specifically, the water washing module 21 of this application consists of three water washing tanks, namely a primary water washing tank, a secondary water washing tank and a tertiary water washing tank, and the filter press module 22 is composed of a three-stage filter press, namely a primary filter press, a secondary filter press and a tertiary filter press.

[0046] The primary washing tank is connected to the primary filter press, the primary filter press is connected to the secondary water tank, the secondary water tank is connected to the secondary filter press, the secondary filter press is connected to the tertiary water tank, the tertiary water tank is connected to the tertiary filter press, and the tertiary filter press is connected to the chemical dosing sedimentation tank 23 and the dryer 31 respectively. The liquid produced by the filter press flows into the chemical dosing sedimentation tank 23, and the solid produced by the filter press is sent to the dryer 31.

[0047] Preferably, the salt solution from the filter press module 22 is passed through a dosing sedimentation tank 23, an MVR evaporator 24, a crystallizer 25, a thickener 26, and a centrifuge 27 to obtain calcium chloride, sodium chloride, and potassium chloride products.

[0048] Preferably, the heat source for the MVR evaporator 24 is provided by the waste heat boiler system 44 of the power plant.

[0049] Furthermore, the fly ash from the desalting and filter press module 22 enters the artificial aggregate unit 3, where most of the moisture is removed by the dryer 31 before entering the fly ash silo 32 for later use.

[0050] Furthermore, the dry fly ash in the fly ash bin 32 is processed into aggregate by an intermittently operating mixing granulator 33 and screening equipment 34.

[0051] The air-to-air heat exchanger in the fly ash in-situ treatment system of this application utilizes the high-temperature flue gas from the existing flue gas system of the waste incineration power plant to heat the air. The hot air is used to achieve safe and stable pyrolysis of fly ash, and the hot air is returned to the waste incinerator to achieve cascaded utilization of energy and reduce energy consumption.

[0052] In this application, the pyrolysis exhaust gas in the fly ash in-situ treatment system is returned to the existing flue gas system of the waste incineration power plant for purification through the existing flue gas treatment system, resulting in lower cost and better effect.

[0053] The fly ash in-situ treatment system of this application detoxifies dioxin-like organic compounds through a low-temperature pyrolysis unit, separates high-value salts from fly ash through a water washing MVR salt separation unit, and achieves harmless resource utilization of fly ash treatment products through an artificial aggregate unit.

[0054] Example 1

[0055] refer to Figure 1 As shown, this embodiment discloses an in-situ fly ash treatment system for a waste incineration power plant, which mainly includes a low-temperature pyrolysis unit 1, a water washing MVR salt separation unit 2, an artificial aggregate unit 3, and the original system of the waste incineration power plant.

[0056] The fly ash from the waste incineration is directly fed into the low-temperature pyrolysis reactor 11 in the low-temperature pyrolysis unit 1 via equipment such as belt conveyors, chain conveyors or bucket elevators, where it exchanges heat with hot air through a wall-type heat exchange mechanism.

[0057] Specifically, the fly ash will be heated to about 400°C in the low-temperature pyrolysis reactor 11 and maintained for more than an hour, and the dioxin-like substances in the fly ash will be reduced from a toxicity equivalent of more than 2000 ng TEQ / kg to less than 50 ng TEQ / kg.

[0058] Pressurized cold air is heated by high-temperature flue gas from the power plant flue gas system 41 via the gas-to-gas heat exchanger 13. After being heated, the high-temperature flue gas returns to a suitable position in the power plant flue gas system 41, while the hot air enters the jacket of the low-temperature pyrolysis reactor 11 to heat fly ash.

[0059] Preferably, the high-temperature flue gas of the power plant flue gas system 41 is extracted from the flue and has a temperature of about 700°C.

[0060] The gas-to-gas heat exchanger 13 converts the heating medium of low-temperature pyrolysis from flue gas to air, and has the following functions: (1) reducing wear and dust accumulation in the heating gas passage, and (2) making the flow rate and temperature of the heating gas easier to control.

[0061] After low-temperature pyrolysis, the fly ash directly enters the cooling section 12. The cooling section adopts a rotary kiln structure with a jacketed structure. Process water is used to rapidly and indirectly cool the detoxified fly ash, so that the temperature of the cooled fly ash is less than 80°C, which can effectively prevent the regeneration of dioxins.

[0062] Nitrogen gas is continuously introduced into the fly ash channel outlet of the cooling section 12. The nitrogen gas is heated in the cooling section 12 and then enters the low-temperature pyrolysis reactor 11. Finally, it returns to the power plant flue gas system 41 together with the gaseous products of low-temperature pyrolysis.

[0063] The nitrogen gas continuously introduced above has the following functions: (1) cooling fly ash, maintaining an inert atmosphere, and preventing the regeneration of dioxins; (2) recovering some of the heat carried by the fly ash; and (3) ensuring the normal progress of the low-temperature pyrolysis reaction of dioxins.

[0064] Preferably, the industrial water used for rapid cooling of fly ash comes from the power plant's circulating water system 42, and the purging nitrogen comes from the power plant's nitrogen system 43.

[0065] The cooled fly ash is conveyed by a multi-stage screw conveyor to the water washing MVR salt separation unit 2, where the salts are separated by the water washing module 21 and the pressure filter module 22.

[0066] Taking a three-stage washing tank and a three-stage filter press as an example, fly ash first enters the first-stage washing tank, then enters the second-stage washing tank after passing through the first-stage plate heat exchanger filter press, then enters the second-stage washing tank, then enters the third-stage washing tank after passing through the second-stage plate heat exchanger filter press, and finally is transported to the artificial aggregate unit 3 by a belt conveyor after passing through the third-stage plate heat exchanger filter press.

[0067] Industrial water first enters the third-stage washing tank, then the second-stage washing tank, and finally the first-stage washing tank. The washing liquid discharged from the first-stage washing tank is transported to the chemical dosing sedimentation tank 23 through pipelines.

[0068] After the washing solution is treated, mixed, and precipitated, the upper clear water is collected in the mixing condensate tank 28. The precipitated liquid enters the evaporator 24 of the MVR device. The evaporated crystal particles are sent to the centrifuge 27 after passing through the crystal slurry tank 25 and the thickener 26 to obtain the product industrial salt.

[0069] Specifically, through the water-washing MVR salt separation unit 2, for every ton of waste incineration fly ash processed, 0.28 tons of potassium chloride wet salt with a moisture content of 6%, 0.14 tons of sodium chloride wet salt with a moisture content of 4%, and 0.59 tons of liquid calcium chloride with a concentration of 45% can be obtained.

[0070] Preferably, the low-temperature, low-pressure steam required by the MVR evaporator 24 is extracted from the steam pipeline of the power plant waste heat boiler system 44, with a temperature of 60-100℃.

[0071] The steam condensate from the MVR evaporator 24 is collected by the mixed condensate tank 28 and enters the water washing module 21 together with the clear water from the upper layer of the dosing sedimentation tank 23.

[0072] After being washed, the fly ash is conveyed to the artificial aggregate unit 3 via a belt conveyor and its moisture content is reduced by the dryer 31. The treated fly ash is then stored in the fly ash silo 32 and periodically transported to the mixing granulator 33 to be mixed with fly ash, slag and cement. Finally, the fly ash is screened by the screening equipment 34 to obtain artificial aggregate.

[0073] Specifically, each ton of waste incineration fly ash can be mixed with bulk industrial solid waste through the artificial aggregate unit 3 to produce 1.76 tons of artificial aggregate. The hardened waste incineration fly ash artificial aggregate can replace natural river sand and manufactured sand with an apparent density of 2200-2600 kg / m3 for construction projects.

[0074] Preferably, the mixing granulator 33 and the screening equipment 34 have a relatively fast production speed and operate in an intermittent mode.

[0075] Preferably, the heat source for the dryer 31 is determined based on the distance to the site and the required heat, namely the flue gas from the power plant flue gas system 41, the steam from the waste heat boiler system 24, and the air from the low-temperature pyrolysis reactor 11.

[0076] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A fly ash in-situ treatment system for a waste incineration power plant, characterized in that, The fly ash in-situ treatment system includes: a low-temperature pyrolysis unit (1), a water washing MVR salt separation unit (2), and an artificial aggregate unit (3); The low-temperature pyrolysis unit (1) includes a low-temperature pyrolysis reactor (11), a cooling section (12) and a gas-to-gas heat exchanger (13). The low-temperature pyrolysis reactor (11) and the cooling section (12) are connected to each other. The cooling section (12) is connected to the water washing MVR salt separation unit (2). The low-temperature pyrolysis unit (1) completes the pyrolysis treatment of the input waste incineration fly ash. Furthermore, the gas-to-gas heat exchanger (13) is connected to the low-temperature pyrolysis reactor (11), and the gas-to-gas heat exchanger (13) provides heat source air to the low-temperature pyrolysis reactor (11). The gas-to-gas heat exchanger (13) is also connected to the flue gas system (41) of the waste incineration power plant, and the flue gas system (41) provides heat source gas to the gas-to-gas heat exchanger (13). The cooling section (12) is also connected to the ammonia system (43) of the waste incineration power plant. The air from the ammonia system (43) is transported to the cooling section (12) to complete the gas preheating and then flows to the low-temperature pyrolysis reactor (11) to carry out the corresponding pyrolysis reaction. The water washing MVR salt separation unit (2) includes a water washing module (21), a filter press module (22), a chemical dosing sedimentation tank (23), an MVR evaporator (24), a crystal slurry tank (25), a thickener (26), and a centrifuge (27) connected in sequence. The salt solution from the filter press module (22) passes through the chemical dosing sedimentation tank (23), the MVR evaporator (24), the crystal slurry tank (25), the thickener (26), and the centrifuge (27) to obtain calcium chloride, sodium chloride, and potassium chloride products. The water washing MVR salt separation unit (2) also includes a mixing condensate tank (28). The dosing sedimentation tank (23) and the MVR evaporator (24) are connected to the mixing condensate tank (28) via pipelines. The mixing condensate tank (28) receives the condensate from the dosing sedimentation tank (23) and the MVR evaporator (24). Thus, the water washing MVR salt separation unit (2) completes the water washing and salt separation treatment of the material input from the low-temperature pyrolysis unit (1). The filter press module (22) is also connected to the artificial aggregate unit (3). The artificial aggregate unit (3) includes a dryer (31), a fly ash bin (32), a mixing granulator (33), and a screening device (34) connected in sequence, which are used to complete the granulation process of the input material.

2. The in-situ fly ash treatment system for waste incineration power plants as described in claim 1, characterized in that, The low-temperature pyrolysis reactor (11) and the gas-to-gas heat exchanger (13) are roller devices with indirect heat exchange.

3. The in-situ fly ash treatment system for waste incineration power plants as described in claim 2, characterized in that, The low-temperature pyrolysis reactor (11) is also provided with a pipeline connected to the power plant flue gas system (41). The heat source air received by the low-temperature pyrolysis reactor (11) flows through the low-temperature pyrolysis reactor (11) and then through the pipeline to the power plant flue gas system (41), and is input into the furnace as combustion air.

4. The in-situ fly ash treatment system for waste incineration power plants as described in claim 1, characterized in that, The cooling section (12) is also connected to the power plant circulating water system (42) of the waste incineration power plant, receiving the cooling medium input from the power plant circulating water system (42) to complete the material cooling treatment of the cooling section (12), and transporting the corresponding cooling medium back to the power plant circulating water system (42) through pipelines.

5. The in-situ fly ash treatment system for waste incineration power plants as described in claim 1, characterized in that, The washing module (21) is equipped with three washing tanks, namely a primary washing tank, a secondary washing tank and a tertiary washing tank. The filter press module (22) is equipped with three filter presses, namely a primary filter press, a secondary filter press and a tertiary filter press.

6. The in-situ fly ash treatment system for waste incineration power plants as described in claim 5, characterized in that, The primary washing tank is connected to the primary filter press, the primary filter press is connected to the secondary water tank, the secondary water tank is connected to the secondary filter press, the secondary filter press is connected to the tertiary water tank, the tertiary water tank is connected to the tertiary filter press, and the tertiary filter press is connected to the chemical dosing sedimentation tank (23) and the dryer (31) respectively. The liquid produced by the filter press flows into the chemical dosing sedimentation tank (23), and the solid produced by the filter press is sent to the dryer (31).

7. The in-situ fly ash treatment system for waste incineration power plants as described in claim 1, characterized in that, The MVR evaporator (24) is connected to the waste heat boiler system (44) of the waste incineration power plant, and the heat source of the MVR evaporator (24) is provided by the waste heat boiler system (44) of the power plant.

Images