Waste steam heat recovery device for waste incineration plant

Abstract

The invention provides a waste incineration plant exhaust steam heat recovery device which comprises an exhaust steam recovery mechanism used for recovering exhaust steam of a deaerator and exhaust steam of a pollution discharge container in a waste incineration plant and centrally gathering the exhaust steam to form heat energy exhaust steam; the heat energy recovery mechanism is communicated and connected with the dead steam recovery mechanism and is used for performing graded recovery on the heat energy dead steam; the recovery coordination module is connected with the heat energy recovery mechanism and used for controlling the temperature and the flow speed of dead steam airflow entering the heat energy recovery mechanism so as to adjust the heat energy recovery efficiency; wherein the heat energy recovery mechanism recovers heat energy in a three-stage recovery mode, and all stages of heat energy recovery are communicated and connected through valves. According to the system, the airflow temperature and flow of each stage of heat exchanger are dynamically adjusted through the recovery coordination module, so that the maximization of the heat recovery efficiency is ensured in real time, the maximization of the heat recovery efficiency is realized in the whole heat recovery process, and the waste steam heat recovery efficiency is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of waste disposal, in particular relates to a waste incineration plant waste heat recovery device. BACKGROUND

[0002] Waste incineration is a process of reducing the volume of waste through appropriate thermal decomposition, combustion, melting and other reactions, and becoming residues or molten solid substances through oxidation at high temperature. Waste incineration facilities must be equipped with flue gas treatment facilities to prevent heavy metals, organic pollutants and other pollutants from being discharged into the environment again. Recycling the heat generated by waste incineration can achieve the purpose of waste resource utilization. Waste incineration is an old and traditional method of waste disposal. Since waste is treated by incineration, the effect of volume reduction is significant, land is saved, and various pathogens can be eliminated, and toxic and harmful substances can be converted into harmless substances, so waste incineration has become one of the main methods of municipal waste disposal. Modern waste incinerators are equipped with good smoke purification devices to reduce air pollution.

[0003] During the operation of the waste incineration plant, the deaerator exhaust and the fixed exhaust are usually directly discharged into the atmosphere, causing a large amount of low-grade heat energy to be wasted (the temperature is usually 100-150℃). Direct discharge causes thermal pollution in the plant area, and the steam may contain trace impurities, affecting the environment. In the prior art, some power plants attempt to recover heat through heat exchangers, but there is a problem of low heat recovery efficiency, which cannot well recover and utilize heat. SUMMARY

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a waste incineration plant waste heat recovery device to solve the problem of low waste incineration waste heat recovery efficiency in the prior art.

[0005] To achieve the above-mentioned purposes and other related purposes, the present application provides a waste incineration plant waste heat recovery device, comprising:

[0006] A waste heat recovery mechanism is used to recover the deaerator exhaust and the exhaust container exhaust in the waste incineration plant and to concentrate and collect the heat energy waste steam; A heat energy recovery mechanism is in conductive connection with the waste heat recovery mechanism and is used to recover the heat energy waste steam in stages; A recovery coordination module is connected with the heat energy recovery mechanism and is used to control the temperature and flow rate of the waste steam flowing into the heat energy recovery mechanism to adjust the heat energy recovery efficiency; The heat energy recovery mechanism recovers heat energy in a three-stage recovery mode, and each stage of heat energy recovery is connected by a valve.

[0007] In an embodiment of the present application, the steam recovery mechanism comprises a buffer tank, input ends of the buffer tank are respectively connected with a first input pipe and a second input pipe, the first input pipe is used for inputting the deaerator exhaust steam, the second input pipe is used for inputting the blowdown vessel exhaust steam, a separation hopper is installed at the top of the buffer tank, first and second filter screens are respectively installed at the top of the separation hopper, the inclination angle of the first filter screen is greater than that of the second filter screen, and a water trap is installed at the top of the separation hopper and used for adsorbing water droplets and particulate matters remaining in the airflow.

[0008] In an embodiment of the present application, the water trap comprises first and second collection tubes installed at the top of the separation hopper, the first and second collection tubes are connected in a through manner by a flexible sleeve, a plurality of airflow grooves are arranged in the first and second collection tubes, protrusions are uniformly arranged on the inner walls of the airflow grooves, and adjusting members are installed at the two sides of the flexible sleeve to clean the interiors of the airflow grooves by the adjusting members.

[0009] In an embodiment of the present application, the adjusting members comprise a hollow disc installed at the center of the interior of the flexible sleeve, a plurality of through holes opposite to the airflow grooves are arranged at the top and bottom of the hollow disc, a piston rod is arranged in each through hole, and a cleaning brush is installed at the end of the piston rod to clean the inner walls of the airflow grooves.

[0010] In an embodiment of the present application, the heat recovery mechanism comprises a flow divider, first, second and third heat exchangers, the input end of the flow divider is connected in a through manner with the top of the water trap through a drain tank, the output ports of the flow divider are respectively connected with first, second and third conveyors, the first conveyor is connected in a through manner with the first heat exchanger, the second conveyor is connected in a through manner with the second heat exchanger, the third conveyor is connected in a through manner with the third heat exchanger, the processed gas is divided by the flow divider, the first heat exchanger is connected in a through manner with the second heat exchanger through a first valve, and the second heat exchanger is connected in a through manner with the third heat exchanger through a second valve.

[0011] In an embodiment of the present application, the heat exchange efficiencies of the first, second and third heat exchangers decrease in sequence, the heat of the first heat exchanger is used for heating desalted water or heating water, and the heat of the second and third heat exchangers is used for a sludge drying system.

[0012] In an embodiment of the present application, the recovery coordination module comprises a core controller, a first temperature sensor, a first flow meter, a second temperature sensor, a second flow meter, a third temperature sensor and a third flow meter installed inside the first heat exchanger, the second heat exchanger and the third heat exchanger, the core controller is configured to calculate target temperature and target flow rate of the first heat exchanger, the second heat exchanger and the third heat exchanger at maximum heat exchange efficiency according to temperature data and flow data of the first temperature sensor, the first flow meter, the second temperature sensor, the second flow meter, the third temperature sensor and the third flow meter, and adjust the flow divider, the first valve and the second valve according to the target temperature and the target flow rate.

[0013] In an embodiment of the present application, the first temperature sensor is configured to detect first inflow temperature of air flow in the first heat exchanger, the second temperature sensor is configured to detect second inflow temperature of air flow in the second heat exchanger, the third temperature sensor is configured to detect third inflow temperature of air flow in the third heat exchanger, and the process of calculating target temperature and target flow rate by the core controller comprises: obtaining basic parameters of the first heat exchanger, the second heat exchanger and the third heat exchanger; establishing a target heat model according to the basic parameters and setting corresponding constraint conditions; iteratively optimizing the target heat model to calculate target temperature and target flow rate corresponding to the numerical maximum of the target heat model; wherein the basic parameters comprise heat transfer coefficient, heat transfer area, efficiency coefficient, specific heat capacity, mass flow and cooling water inlet temperature, and the target heat model is updated according to pre-set time.

[0014] In an embodiment of the present application, the calculation process of the target heat model satisfies the following formula:

[0015] wherein, represents maximum recovered heat, represents heat transfer coefficient of the i-th heat exchanger, represents heat transfer area of the i-th heat exchanger, represents heat exchange efficiency coefficient of the i-th heat exchanger, the heat exchange efficiency coefficient is a ratio of actual heat transfer amount of the heat exchanger to theoretical maximum possible heat transfer amount, and the value is between 0 and 1, represents logarithmic mean temperature difference of the i-th heat exchanger, represents inflow temperature of the i-th heat exchanger, represents inlet temperature of the i-th heat exchanger, represents outflow temperature of the i-th heat exchanger, Tout,i represents the outlet temperature of the i-th heat exchanger.

[0016] As described above, the waste incineration plant waste heat recovery device has the following beneficial effects: The waste incineration plant waste heat recovery device of the present application has the following beneficial effects: BRIEF DESCRIPTION OF DRAWINGS

[0017] Fig. 1 FIG. 1 shows the overall structure of the waste incineration plant waste heat recovery device of the present application.

[0018] Fig. 2 FIG. 4 shows the structure of the deaerator in the waste incineration plant waste heat recovery device of the present application.

[0019] Fig. 3 FIG. 5 shows the structure of the cleaning brush in the waste incineration plant waste heat recovery device of the present application. DETAILED DESCRIPTION

[0020] The present application will be described in detail below with reference to specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the specification. The present application can also be implemented or applied in different specific embodiments, and the details in the specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0021] It should be noted that the diagrams provided in the following embodiments only schematically illustrate the basic concept of the present application, and only show the components related to the present application in the diagrams, not the number, shape and size of the components when actually implemented. The actual implementation of each component may be randomly changed in terms of type, number and proportion, and the layout type of the components may also be more complex.

[0022] The waste incineration plant waste heat recovery device provided by the application can realize the maximization of heat recovery efficiency in the whole heat recovery process, and effectively improve the heat recovery efficiency.

[0023] Reference Figs. 1 to 3 The application provides a waste incineration plant waste heat recovery device, which comprises the following components. A waste heat recovery mechanism 1 is used for recovering the deaerator exhaust steam and the exhaust steam of the pollution container in the waste incineration plant, and collecting and concentrating the exhaust steam to form heat energy exhaust steam. A heat energy recovery mechanism 2 is in conductive connection with the waste heat recovery mechanism 1 and is used for recovering the heat energy exhaust steam in stages. A recovery coordination module 3 is connected with the heat energy recovery mechanism 2 and is used for controlling the temperature and flow rate of the exhaust steam flowing into the heat energy recovery mechanism to adjust the heat energy recovery efficiency. The heat energy recovery mechanism 2 adopts a three-stage recovery mode to recover heat energy, and the heat energy recovery mechanisms at each stage are in conductive connection through valves.

[0024] In the embodiment, the deaerator exhaust steam and the exhaust steam of the pollution container discharged from the waste incineration plant are collected together by the waste heat recovery mechanism 1 to form heat energy exhaust steam, the heat energy exhaust steam is recovered in multiple stages by the heat energy recovery mechanism 2, and the recovery coordination module 3 is used for real-time control to adjust the heat energy recovery efficiency in the recovery process, so that the heat energy recovery effect is improved.

[0025] In some embodiments, the waste heat recovery mechanism 1 comprises a buffer tank 11, the input end of the buffer tank 11 is in conductive connection with a first input pipe 12 and a second input pipe 13 respectively, the first input pipe 12 is used for inputting the deaerator exhaust steam, the second input pipe 13 is used for inputting the exhaust steam of the pollution container, a separation hopper 14 is installed at the top of the buffer tank 11, a first filter screen 15 and a second filter screen 16 are respectively installed on the top of the separation hopper 14, the inclination angle of the first filter screen 15 is greater than that of the second filter screen 16, a water separator 17 is installed on the top of the separation hopper 14, and the water separator 17 is used for adsorbing water droplets and particulate matters remaining in the airflow.

[0026] In the embodiment, the steam extraction mechanism 1 inputs the collected deaerator exhaust steam through the first input pipe 12, inputs the blowdown vessel exhaust steam through the second input pipe 13, and after being mixed into the buffer tank 11, the impurities are separated through the separation hopper 14 to remove the particles and water droplets in the steam, and the subsequent heat energy recovery is facilitated. The steam flow entering the buffer tank 11 collides with the separation hopper 14 at the top, the flow rate is reduced, and the steam slowly passes through the first filter screen 15 and the second filter screen 16 on the two sides, thereby prolonging the time of the steam flow passing through the first filter screen 15 and the second filter screen 16, and improving the filtering effect. Moreover, the inclination angle of the first filter screen 15 is greater than that of the second filter screen 16, so that the steam flow can pass through the first filter screen 15 and the second filter screen 16 at different flow rates, thereby ensuring that the flow after filtering does not appear to affect the subsequent water removal efficiency and heat recovery efficiency.

[0027] Further, by installing the water remover 17 at the top of the separation hopper 14, the water droplets and residual particles remaining in the flow after filtering are further removed by the water remover 17, thereby improving the subsequent heat energy recovery efficiency.

[0028] Specifically, the water remover 17 includes a first collection cylinder 171 and a second collection cylinder 172 installed at the top end of the separation hopper 14, the first collection cylinder 171 and the second collection cylinder 172 are connected through a flexible sleeve 173, and a plurality of flow grooves 174 are arranged in the first collection cylinder 171 and the second collection cylinder 172. The inner walls of the flow grooves 174 are uniformly provided with protrusions, and adjusting members 4 are installed on both sides of the flexible sleeve 173 to clean the inside of the flow grooves 174 through the adjusting members 4.

[0029] In the embodiment, after the flow passes through the first filter screen 15 and the second filter screen 16, it enters the water remover 17 at the top to remove water. First, it enters the first collection cylinder 171, then enters the flexible sleeve 173, and then enters the second collection cylinder 172 at the top. Since the first collection cylinder 171 and the second collection cylinder 172 are both provided with flow grooves 174 with protrusions, the flow effectively removes residual water vapor and particles when passing through the flow grooves 174. For impurities remaining in the flow grooves 174, the adjusting members 4 are used for cleaning, thereby avoiding the problem of blockage affecting subsequent use.

[0030] In some embodiments, the adjusting member 4 comprises a hollow disc 41 installed in the center of the flexible sleeve 173, the top and bottom of the hollow disc 41 are provided with a plurality of through holes 42 opposite to the air flow grooves 174, the through holes 42 are provided with a piston rod 43, the end of the piston rod 43 is provided with a cleaning brush 44 to clean the inner wall of the air flow groove 174.

[0031] Specifically, when the air flow groove 174 needs to be cleaned, the piston rod 43 installed in the hollow disc 41 is pushed up and down, so that the cleaning brush 44 at the end of the piston rod 43 enters the air flow groove 174 to clean, thereby effectively removing the sundries remaining in the air flow groove 174 and ensuring the subsequent processing efficiency.

[0032] Further, referring to Fig. 3 Since the cleaning brush 44 is provided with protrusions and recesses on the side surface and is made of breathable material, when the piston rod 43 pushes the cleaning brush 44 into the air flow groove 174, the air flow groove 174 is not completely blocked, ensuring normal exhaust of the air flow groove 174 and not affecting the work of the water remover 17.

[0033] In some embodiments, the heat energy recovery mechanism 2 comprises a flow divider 21, a first heat exchanger 22, a second heat exchanger 23 and a third heat exchanger 24, the input end of the flow divider 21 is connected to the top end of the water remover 17 through the drain tank 5, the output of the flow divider 21 is connected with a first conveyor 25, a second conveyor 26 and a third conveyor 27, the first conveyor 25 is connected to the first heat exchanger 22, the second conveyor 26 is connected to the second heat exchanger 23, and the third conveyor 27 is connected to the third heat exchanger 24, so that the treated gas is divided by the flow divider 21, the first heat exchanger 22 and the second heat exchanger 23 are connected through a first valve 28, the second heat exchanger 23 and the third heat exchanger 24 are connected through a second valve 29, the heat exchange efficiency of the first heat exchanger 22, the second heat exchanger 23 and the third heat exchanger 24 decreases in turn, the heat of the first heat exchanger 22 is used to heat the desalted water or heating water, and the heat of the second heat exchanger 23 and the third heat exchanger 24 is used for sludge drying system.

[0034] In the embodiment, after the air flow is processed, the diverter 21 directly delivers the air flow to the first heat exchanger 22, the second heat exchanger 23 and the third heat exchanger 24 through the first conveyor 25, the second conveyor 26 and the third conveyor 27 for heat exchange treatment, and the first heat exchanger 22 and the second heat exchanger 23 are connected through the first valve 28, and the second heat exchanger 23 and the third heat exchanger 24 are connected through the second valve 29, so as to realize the conduction between adjacent heat exchangers and improve the heat exchange efficiency. The heat exchange temperature of the first heat exchanger 22 is higher than that of the second heat exchanger 23, and the heat exchange temperature of the second heat exchanger 23 is higher than that of the third heat exchanger 24, so as to realize the staged heat exchange of the heat exchangers and improve the heat exchange efficiency.

[0035] In some other embodiments, the recycling coordination module 3 comprises a core controller 31, a first temperature sensor 32, a first flow meter 33, a second temperature sensor 34, a second flow meter 35, a third temperature sensor 36 and a third flow meter 37 installed in the first heat exchanger 22, the second heat exchanger 23 and the third heat exchanger 24, and the core controller 31 is used to calculate the target temperature and the target flow rate of the first heat exchanger 22, the second heat exchanger 23 and the third heat exchanger 24 at the maximum heat exchange efficiency according to the temperature data and the flow data of the first temperature sensor 32, the first flow meter 33, the second temperature sensor 34, the second flow meter 35, the third temperature sensor 36 and the third flow meter 37, and adjust the diverter 21, the first valve 28 and the second valve 29 according to the target temperature and the target flow rate.

[0036] In the embodiment, the recycling coordination module 3 collects temperature data and flow data through the first temperature sensor 32, the first flow meter 33, the second temperature sensor 34, the second flow meter 35, the third temperature sensor 36 and the third flow meter 37 installed in the first heat exchanger 22, the second heat exchanger 23 and the third heat exchanger 24, so as to calculate the target temperature and the target flow rate at the maximum heat exchange efficiency, and adjust the diverter 21, the first valve 28 and the second valve 29 according to the target temperature and the target flow rate.

[0037] In some other embodiments, the first temperature sensor 32 is used to detect the first inflow temperature of the air flow in the first heat exchanger 22, the second temperature sensor 34 is used to detect the second inflow temperature of the air flow in the second heat exchanger 23, and the third temperature sensor 36 is used to detect the third inflow temperature of the air flow in the third heat exchanger 24, and the process of calculating the target temperature and the target flow rate by the core controller 31 comprises: obtaining the basic parameters of the first heat exchanger, the second heat exchanger and the third heat exchanger; a target heat model is established according to the basic parameters, and a constraint condition is set correspondingly; The target heat model is iteratively optimized to calculate a target temperature and a target flow rate corresponding to a numerical maximum of the target heat model; The basic parameters include a heat transfer coefficient, a heat transfer area, an efficiency coefficient, a specific heat capacity, a mass flow rate, and a cooling water inlet temperature, and the target heat model is updated at a preset time.

[0038] In this embodiment, after the inflow temperature and flow data inside the first heat exchanger 22, the second heat exchanger 23, and the third heat exchanger 24 are detected by the first temperature sensor 32, the first flow meter 33, the second temperature sensor 34, the second flow meter 35, the third temperature sensor 36, and the third flow meter 37, the core controller 31 performs iterative optimization according to the detected data to calculate a target temperature and a target flow rate at which the heat exchange efficiency is maximum.

[0039] Specifically, first, the basic parameters of the heat exchanger are obtained, including a heat transfer coefficient, a heat transfer area, an efficiency coefficient, a specific heat capacity C, a mass flow rate m, and a cooling water inlet temperature The cooling water inlet temperature represents the temperature of the cooling water entering the heat exchanger, and in the initial state, the cooling water inlet temperatures of the three heat exchangers are all preset values.

[0040] Then, a target heat model is established according to the basic parameters, and a corresponding constraint condition is set, i.e., the numerical values of the final target temperature and the target flow rate are between a preset maximum value and a minimum value, to avoid exceeding the limit.

[0041] The calculation process of the target heat model satisfies the following formula:

[0042] wherein, represents the maximum recovered heat, represents the heat transfer coefficient of the i-th heat exchanger, represents the heat transfer area of the i-th heat exchanger, represents the heat exchange efficiency coefficient of the i-th heat exchanger, which is the ratio of the actual heat transfer amount of the heat exchanger to the theoretically maximum possible heat transfer amount, and the value is between 0 and 1, represents the logarithmic mean temperature difference of the i-th heat exchanger, represents the inflow temperature of the i-th heat exchanger, represents the inlet temperature of the i-th heat exchanger, represents the outflow temperature of the i-th heat exchanger, represents the outlet temperature of the i-th heat exchanger.

[0043] After the target heat model is iteratively optimized, in the iterative optimization process, since the first heat exchanger 22, the second heat exchanger 23 and the third heat exchanger 24 are connected in series, the outlet temperature of the previous heat exchanger is equivalent to the inlet temperature of the next heat exchanger, and the temperature of the cooling fluid in the heat exchanger changes with the number of heat exchangers. And the tube side pressure drop is less than the preset maximum value. That is:

[0044] represents the tube side pressure drop of the i-th heat exchanger, represents the preset maximum value of the tube side pressure drop, f is the friction coefficient, L i is the tube length of the i-th heat exchanger, D i is the tube diameter of the i-th heat exchanger, represents the fluid density of the cooling liquid in the i-th heat exchanger.

[0045] In the specific iterative optimization, first, set the initial values of the target temperature and the target flow rate to be the average of the maximum value and the minimum value T and V, and allocate the corresponding temperature and flow rate according to the efficiency proportion of the heat exchanger, and take the total heat exchange amount in the current state as the reference value Q. After that, split and iterate to the left and right of the average temperature T and the average flow rate V, and calculate the total heat exchange amount Q L and Q R of the heat exchanger after splitting and iterating to the left and right. L When the heat Q L to the left is greater than the reference value Q, the current split point is taken as the reference point to continue splitting to the left and right, and the heat Q L at the current split is taken as the reference value Q, and the above process is repeated until the total heat exchange amount Q R obtained by left and right splitting is not more than the reference value Q of the current split point. Then, the target temperature and the target flow rate at the current split point are taken as the target temperature and the target flow rate, the iterative optimization process is completed, and the target temperature and the target flow rate that meet the requirements are output after verifying that they meet the previous constraint conditions, thereby completing the iteration process. After that, the core controller 31 adjusts the flow divider 21, the first valve 28 and the second valve 29 according to the calculated target temperature and target flow rate, so that the temperature and flow rate of the gas flow in the first heat exchanger 22, the second heat exchanger 23 and the third heat exchanger 24 reach the target temperature and the target flow rate, thereby maximizing the heat exchange efficiency, maximizing the utilization of the exhaust steam heat, and reducing heat waste.

[0046] In summary, the waste incineration plant steam heat recovery device of the present application, the steam recovery mechanism concentrates the deaerator exhaust and the exhaust of the pollution container in the waste incineration plant, and the heat energy recovery mechanism classifies the heat energy steam recovery, and in the recovery process, the recovery coordination module adjusts the airflow temperature and flow of each stage of the heat exchanger, so as to maximize the heat recovery efficiency, so as to maximize the heat recovery efficiency in the whole heat recovery process, and effectively improve the heat recovery efficiency. Therefore, the present application effectively overcomes the shortcomings of the prior art and has high industrial utilization value.

[0047] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical idea disclosed by the present application should be covered by the claims of the present application.

Claims

1. A waste incineration plant exhaust steam heat recovery device characterized by comprising: The utility model relates to a waste heat recovery system for waste incineration plant, which comprises: a waste heat recovery mechanism for recovering the exhaust steam of deaerator and exhaust steam of blow tank and collecting and forming heat energy waste steam; a heat recovery mechanism connected with the waste heat recovery mechanism for grading recovery of the heat energy waste steam; a recovery coordination module connected with the heat recovery mechanism for controlling the temperature and flow rate of the waste steam entering the heat recovery mechanism to adjust the heat recovery efficiency; wherein the heat recovery mechanism adopts a three-stage recovery mode, and each stage is connected by a valve.

2. The waste incineration plant exhaust heat recovery device according to claim 1, characterized by, The waste heat recovery mechanism comprises a buffer tank, the input end of the buffer tank is connected with a first input pipe and a second input pipe, the first input pipe is used for inputting the deaerator exhaust steam, the second input pipe is used for inputting the exhaust steam of blow tank, a separation hopper is installed at the top of the buffer tank, a first filter screen and a second filter screen are installed on both sides of the top of the separation hopper, the inclination angle of the first filter screen is greater than that of the second filter screen, and a water trap is installed on the top of the separation hopper and used for adsorbing water droplets and particulate matters remaining in the airflow.

3. The waste incineration plant exhaust heat recovery device according to claim 2, characterized by, The water trap comprises a first collection cylinder and a second collection cylinder installed at the top of the separation hopper, the first collection cylinder and the second collection cylinder are connected by a flexible sleeve, a plurality of airflow grooves are arranged in the first collection cylinder and the second collection cylinder, protrusions are uniformly arranged on the inner wall of the airflow grooves, and adjusting members are installed on both sides of the flexible sleeve to clean the inside of the airflow grooves through the adjusting members.

4. The waste incineration plant exhaust heat recovery device according to claim 3, characterized by, The adjusting member comprises a hollow disc installed at the center of the flexible sleeve, a plurality of through holes opposite to the airflow grooves are arranged on the top and bottom of the hollow disc, a piston rod is arranged in each through hole, and a cleaning brush is installed at the end of the piston rod to clean the inner wall of the airflow groove.

5. The waste incineration plant exhaust heat recovery device according to claim 2, characterized by, The heat recovery mechanism comprises a flow divider, a first heat exchanger, a second heat exchanger and a third heat exchanger, the input end of the flow divider is connected with the top of the water trap through a drain tank, the output port of the flow divider is connected with a first conveyor, a second conveyor and a third conveyor, the first conveyor is connected with the first heat exchanger, the second conveyor is connected with the second heat exchanger, and the third conveyor is connected with the third heat exchanger to divide the treated gas through the flow divider, the first heat exchanger and the second heat exchanger are connected by a first valve, and the second heat exchanger and the third heat exchanger are connected by a second valve.

6. The waste incineration plant exhaust heat recovery device according to claim 5, characterized by The heat exchange efficiency of the first heat exchanger, the second heat exchanger and the third heat exchanger decreases in turn, the heat of the first heat exchanger is used for heating desalted water or heating water, and the heat of the second heat exchanger and the third heat exchanger is used for sludge drying system.

7. The waste incineration plant exhaust heat recovery device according to claim 5, characterized by, The recovery coordination module comprises a core controller, a first temperature sensor, a first flow meter, a second temperature sensor, a second flow meter, a third temperature sensor and a third flow meter installed inside the first heat exchanger, the second heat exchanger and the third heat exchanger, the core controller is used for calculating target temperature and target flow rate of the first heat exchanger, the second heat exchanger and the third heat exchanger at maximum heat exchange efficiency according to temperature data and flow data of the first temperature sensor, the first flow meter, the second temperature sensor, the second flow meter, the third temperature sensor and the third flow meter, and adjusting the flow divider, the first valve and the second valve according to the target temperature and the target flow rate.

8. The waste incineration plant exhaust heat recovery device according to claim 7, characterized by, The first temperature sensor is used for detecting first inflow temperature of airflow in the first heat exchanger, the second temperature sensor is used for detecting second inflow temperature of airflow in the second heat exchanger, the third temperature sensor is used for detecting third inflow temperature of airflow in the third heat exchanger, and the process of calculating target temperature and target flow rate by the core controller comprises: obtaining basic parameters of the first heat exchanger, the second heat exchanger and the third heat exchanger; establishing a target heat model according to the basic parameters and setting a constraint condition correspondingly; iteratively optimizing the target heat model to obtain target temperature and target flow rate corresponding to a numerical maximum of the target heat model; wherein the basic parameters comprise heat transfer coefficient, heat transfer area, efficiency coefficient, specific heat capacity, mass flow and cooling water inlet temperature, and the target heat model is updated according to a preset time; the constraint condition is that numerical values of the final target temperature and the target flow rate are between a preset maximum value and a preset minimum value, so as to avoid exceeding the limit; the iterative optimization process comprises: firstly setting initial values of the target temperature and the target flow rate as mean values T and V of the maximum value and the minimum value, and distributing corresponding temperature and flow rate according to efficiency proportion of the heat exchanger, taking total heat exchange amount in the current state as a reference value Q, then splitting and iterating to left and right of the mean temperature T and the mean flow rate V, and calculating total heat exchange amounts QL and QR of the heat exchanger after splitting and iterating, when the heat amount QL after splitting to the left is greater than the reference value Q, taking the current splitting point as a reference point to continue splitting to left and right, taking the heat amount QL at the current splitting as the reference value Q, repeating the above process until the total heat exchange amounts QL and QR obtained by finally splitting to left and right are both not more than the reference value Q at the current splitting point, then taking the temperature and flow rate at the current splitting point as the target temperature and the target flow rate, and outputting the target temperature and the target flow rate meeting the requirements after verifying the constraint condition, so as to complete the iterative process.

9. The waste incineration plant exhaust heat recovery device according to claim 8, characterized by, The calculation process of the target heat model satisfies the following formula: wherein, represents the maximum recovered heat, represents the heat transfer coefficient of the i-th heat exchanger, represents the heat transfer area of the i-th heat exchanger, represents the heat exchange efficiency coefficient of the i-th heat exchanger, which is the ratio of the actual heat transfer amount of the heat exchanger to the theoretically maximum possible heat transfer amount, and has a value between 0 and 1, represents the logarithmic mean temperature difference of the i-th heat exchanger, represents the inflow temperature of the i-th heat exchanger, represents the inlet temperature of the i-th heat exchanger, represents the outflow temperature of the i-th heat exchanger, represents the outlet temperature of the i-th heat exchanger.

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