Sludge incineration tail gas treatment system and energy storage heat exchanger

Abstract

The invention relates to the technical field of energy utilization and energy conservation and emission reduction, and discloses a sludge incineration tail gas treatment system and an energy storage heat exchanger. The system comprises a tail gas purification module, a carbon capture and solidification module, a circulating power generation module, an air dehumidification heat pump module and a cascade energy storage module. The tail gas purification module is used for sequentially carrying out particulate matter filtration, desulfurization, electrostatic dust collection and denitration treatment on tail gas discharged by the incinerator; the carbon capture and solidification module is used for collecting CO2 in the tail gas through a temperature swing adsorption and low-temperature cooling technology; the circulating power generation module is used for converting low-grade waste heat in the tail gas into electric energy through an organic Rankine cycle technology; the air dehumidification heat pump module is used for dehumidifying and preheating air entering the incinerator; the stepped energy storage module is used for conducting graded recovery and management on waste heat of different temperature zones in tail gas in the purification process. According to the system, various pollutants in the tail gas are efficiently removed, and waste heat of different temperature grades is recycled and utilized in a graded mode.

Description

Technical Field

[0001] The invention relates to the technical field of energy utilization and energy conservation and emission reduction, and in particular to a sludge incineration tail gas treatment system and an energy storage heat exchanger. Background Art

[0002] As an important part of urban solid waste management, sludge disposal has received great attention for its resource utilization, volume reduction and harmless treatment. Incineration, as the current mainstream method of sludge volume reduction, has been promoted on a large scale due to its advantages such as small land occupation, high reduction rate and energy recovery.

[0003] The high-temperature tail gas generated during sludge incineration contains a large amount of pollutants, such as sulfur dioxide (SO2), nitrogen oxides (NO x ), particulate matter (PM), carbon dioxide (CO2) and heavy metal elements, etc., with the characteristics of high temperature, complex composition and great difficulty in treatment. The current mainstream tail gas treatment system focuses more on the purification of pollutants itself, and the emission of greenhouse gases such as CO2 is insufficiently controlled, and the waste heat utilization rate is low, resulting in poor overall energy efficiency and difficulty in meeting the requirements of green and low-carbon development. In addition, the high moisture content in the incineration air will also seriously affect the efficiency of the system: on the one hand, it reduces the calorific value of sludge combustion, and on the other hand, it increases the water vapor content in the tail gas, aggravating equipment corrosion, especially in acidic gases (SO2, NO x ) is more likely to cause low-temperature corrosion problems when condensing, affecting the long-term operational stability of the system. Traditional exhaust heat exchange equipment mostly uses shell and tube heat exchangers, which have significant limitations in dealing with high-particle, highly corrosive exhaust gases. Particulate matter and heavy metals are easily accumulated and deposited inside the heat transfer tubes, causing blockages, increased pressure drop, and decreased heat exchange efficiency. Frequent maintenance or replacement is required, which greatly affects the economic efficiency of system operation. Therefore, it is urgent to develop a new type of heat exchange equipment that has anti-blocking capabilities, is suitable for harsh exhaust gas environments, and has cascade thermal energy storage capabilities, and to build an integrated exhaust gas treatment system to collaboratively achieve the dual goals of pollution control and energy recovery. Summary of the invention

[0004] In order to solve the technical problems existing in the prior art, the present invention provides a sludge incineration exhaust gas treatment system and an energy storage heat exchanger. The system takes the energy storage heat exchanger as the core unit, integrates the functions of exhaust gas purification, cascade waste heat energy storage, carbon capture and solidification, cycle power generation and air dehumidification and preheating, realizes the efficient removal of various pollutants in the exhaust gas, and graded recovery and utilization of waste heat of different temperature levels.

[0005] To achieve the above object, the present invention provides the following technical solutions: The invention discloses a sludge incineration tail gas treatment system, comprising: a tail gas purification module, a carbon capture and solidification module, a circulation power generation module, an air dehumidification heat pump module and a cascade energy storage module.

[0006] The tail gas purification module is used to successively carry out particulate filtration, desulfurization, electrostatic precipitation and denitrification treatment on the tail gas discharged from the incinerator; The carbon capture and solidification module is used to collect CO2 in the tail gas through temperature swing adsorption and cryogenic cooling technology; The circulating power generation module is used to convert the low-grade waste heat in the tail gas into electric energy through the organic Rankine cycle technology; The air dehumidification heat pump module is used to dehumidify and preheat the air entering the incinerator; The cascade energy storage module is used to hierarchically recover and manage the waste heat in different temperature zones of the tail gas during the purification process; the cascade energy storage module includes a first energy storage heat exchanger, a second energy storage heat exchanger, a third energy storage heat exchanger and a fourth energy storage heat exchanger; among them, the first energy storage heat exchanger is used to cool the tail gas after particulate filtration treatment to above the first temperature threshold and store high-grade waste heat; the second energy storage heat exchanger is used to cool the tail gas cooled by the first energy storage heat exchanger to above the second temperature threshold and store low-grade waste heat; the first energy storage heat exchanger and the second energy storage heat exchanger also use the waste heat stored in themselves to gradually raise the temperature of the tail gas after electrostatic precipitation and desulfurization to above the first temperature threshold for denitrification treatment, and the temperature of the tail gas rises after denitrification; the third energy storage heat exchanger is used to cool the tail gas after denitrification to above the first temperature threshold and store high-grade waste heat, and at the same time use this waste heat to convert the low-boiling working fluid in the circulating power generation module from liquid to steam; the fourth energy storage heat exchanger is used to cool the tail gas cooled by the third energy storage heat exchanger to above the second temperature threshold and store low-grade waste heat, and at the same time use this waste heat to further heat the air dehumidified and preheated by the air dehumidification heat pump module to send it into the incinerator.

[0007] As a further improvement of the above solution, independent shell passes and tube passes are provided inside all the energy storage heat exchangers. The shell pass is used to circulate the cold medium, the tube pass is used to circulate the hot medium, and an energy storage medium is also provided between the shell pass and the tube pass for absorbing the heat in the hot medium and releasing it to the cold medium.

[0008] As a further improvement of the above solution, the tail gas purification module includes a bag filter, a desulfurization tower, an electrostatic precipitator and a denitrification tower, which are respectively used for particulate filtration, desulfurization, electrostatic precipitation and denitrification treatment of the tail gas; the tail gas purification module also includes an induced draft fan for providing power for the tail gas transmission; The carbon capture and solidification module includes a carbon capture device, a refrigeration unit, a liquid storage tank and a cold cabinet; among them, the carbon capture device adopts temperature swing adsorption technology to drive the adsorbent to selectively adsorb and desorb CO2 at different temperatures. The desorbed CO2 is sent to the refrigeration unit for liquefaction and stored in the liquid storage tank, and the CO2 is converted into dry ice form through cryogenic cooling process and stored in the cold cabinet; The cyclic power generation module includes a steam turbine, a generator, a regenerator, an exhaust tower, and a centrifugal pump. Among them, after the low-boiling working fluid is heated and converted into steam in the shell side of the energy storage heat exchanger III, it enters the steam turbine to drive the rotation of the steam turbine impeller, thereby driving the coupled generator to generate electricity. After the low-boiling working fluid steam loses energy during work, it exchanges waste heat with the cooled tail gas that has collected CO2 in the regenerator to condense into a liquid state, and then is transported back to the shell side of the energy storage heat exchanger III by the centrifugal pump. The tail gas after the waste heat exchange is discharged to the atmosphere by the exhaust tower (18). The air dehumidification heat pump module includes a blower, a compressor, an evaporator, an expansion valve, and a condenser, which are connected in sequence to form a refrigerant circulation system. The refrigerant sequentially passes through the expansion valve, the evaporator, the compressor, and the condenser to complete the reverse Carnot cycle and exchange heat with the fresh air sent by the blower. The air is cooled to below the dew point temperature in the evaporator, thereby separating water to complete dehumidification, and then is preheated through the condenser.

[0009] As a further improvement of the above solution, the cascade energy storage module further includes a buffer tank I, a switching valve I, a buffer tank II, and a switching valve II. Among them, according to the transmission direction of the tail gas, the tail gas discharge port of the incinerator, the bag filter, the induced draft fan, the tube side of the energy storage heat exchanger I, the tube side of the energy storage heat exchanger II, the buffer tank I, the switching valve I, the desulfurization tower, the electrostatic precipitator, the shell side of the energy storage heat exchanger II, the shell side of the energy storage heat exchanger I, the denitration tower, the tube side of the energy storage heat exchanger III, the tube side of the energy storage heat exchanger IV, the buffer tank II, the switching valve II, the carbon capture device, the regenerator, and the exhaust tower are connected in sequence to form a complete tail gas treatment flow path.

[0010] As a further improvement of the above solution, temperature sensors are provided at both the inlet and outlet of the tube side of all energy storage heat exchangers, and temperature sensors are also provided inside the energy storage media of all energy storage heat exchangers; flow sensors are also provided in the tube side of all energy storage heat exchangers. The sludge incineration tail gas treatment system further includes: A controller, which is used to calculate the heat input of the hot side of each energy storage heat exchanger according to the monitoring data collected by the temperature sensors and flow sensors, and combine the target heat absorption of the energy storage medium to calculate the heat balance deviation value, thereby making the following control strategies: When the heat balance deviation values of the energy storage heat exchanger I and the energy storage heat exchanger II both exceed a preset deviation threshold, control the switching valve I to open; When the heat balance deviation values of the energy storage heat exchanger III and the energy storage heat exchanger IV both exceed the deviation threshold, control the switching valve II to open; Among them, the heat input of the hot side of the energy storage heat exchanger The calculation formula is: ; In the formula, is the mass flow rate of the hot medium in the tube side, is the specific heat capacity of the hot medium, is the temperature difference between the inlet and outlet of the hot medium in the tube side, is the monitoring time; The target heat absorption of the energy storage medium The calculation formula is: ; In the formula, is the mass of the energy storage medium, is the latent heat of phase change of the energy storage medium, is the specific heat capacity of the energy storage medium, is the temperature difference required to reach the target temperature; The heat balance deviation value The calculation formula is: .

[0011] As a further improvement of the above solution, in the air dehumidification heat pump module, temperature sensors and humidity sensors are both arranged at the inlet of the shell side of the evaporator and the outlet of the shell side of the condenser; a temperature sensor is arranged at the outlet of the shell side of the energy storage heat exchanger four; The controller is also used to calculate the dehumidification amount and dehumidification performance coefficient related to the air dehumidification heat pump module, and thus make the following control strategies: When the temperature at the outlet of the shell side of the energy storage heat exchanger four is lower than a preset temperature threshold, control the speed of the blower to decrease, so as to reduce the mass flow rate of the air and extend the residence time of the air in the shell side of the energy storage heat exchanger four, thereby enhancing the heating degree of the air; When the dehumidification amount is less than a preset target dehumidification amount, adjust the operating frequency of the compressor to enhance the cooling capacity output on the evaporator side; When the dehumidification performance coefficient is lower than the preset performance evaluation threshold, control the speed of the blower to decrease to reduce the mass flow rate of the air and extend the residence time of the air in the evaporator, thereby enhancing the dehumidification degree; among them, the dehumidification amount The calculation formula is: ; Among them, and are respectively the absolute moisture content of the air at the inlet of the shell side of the evaporator and the outlet of the shell side of the condenser, with the unit of kg water / kg dry air; The special dehumidification performance coefficient The calculation formula is: ; In the formula, is the mass flow rate of the air, is the condensation latent heat of water vapor, is the input power of the air dehumidification heat pump module.

[0012] As a further improvement of the above solution, in the tail gas purification module, a wet process is used for desulfurization treatment, and a selective catalytic reduction process is used for denitrification treatment.

[0013] The present invention also discloses an energy storage heat exchanger, which is applied to the above-mentioned sludge incineration tail gas treatment system; the energy storage heat exchanger includes a heat exchanger housing and energy storage heat exchange tubes; the energy storage heat exchange tubes are in a double-layer nested test tube-like structure, and an energy storage medium is filled in the interlayer thereof; the top end of the energy storage heat exchange tube is closed and the bottom end is open, and it is vertically installed on the bottom wall of the heat exchanger housing, thereby dividing the inner cavity of the heat exchanger housing into a shell side and a tube side.

[0014] As a further improvement of the above solution, the energy storage heat exchanger further includes a central cylinder, an inlet header and an outlet header; the inlet header, the outlet header and the heat exchanger housing are adjacently connected in sequence from bottom to top to form a tower-like structure; a first through hole communicating with the outlet header is opened on the bottom wall of the heat exchanger housing, and the size of the first through hole is adapted to the central circular hole at the bottom end of the energy storage heat exchange tube; the central cylinder is coaxially arranged with the energy storage heat exchange tube, the bottom end of the central cylinder is fixedly connected to the bottom wall of the outlet header, the top end of the central cylinder extends into the energy storage heat exchange tube through the first through hole, and there is a gap between the top end of the central cylinder and the inner wall top end of the energy storage heat exchange tube, and there is an annular gap between the outer wall of the central cylinder and the inner wall of the energy storage heat exchange tube in the radial direction, so as to form a bent flow path in the tube side of the energy storage heat exchanger; a second through hole communicating with the inlet header is opened on the bottom wall of the outlet header, and the size of the second through hole is adapted to the central circular hole at the bottom end of the central cylinder; a tube side inlet and a tube side outlet are respectively arranged on the opposite side walls of the inlet header and the outlet header; a shell side inlet and a shell side outlet are respectively arranged on the opposite side walls of the heat exchanger housing, and the height of the shell side inlet is lower than the height of the shell side outlet.

[0015] As a further improvement of the above solution, a plurality of energy storage heat exchange tubes are provided in the energy storage heat exchanger, and they are arranged in an array on the horizontal plane; reinforcing ribs are further arranged in the interlayer of each energy storage heat exchange tube; the outer surfaces of the central cylinder and the energy storage heat exchange tubes are both made of duplex stainless steel; among them, the energy storage media of the first energy storage heat exchanger and the third energy storage heat exchanger are the same, the energy storage media of the second energy storage heat exchanger and the fourth energy storage heat exchanger are the same, and the phase change temperature of the energy storage media of the former two is higher than that of the latter two.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. The tail gas treatment system disclosed by the present invention uses an energy storage heat exchanger as the core waste heat recovery unit, and through multi-stage heat exchange and dynamic energy management, realizes the efficient heat energy storage and utilization of incineration tail gas in the high-temperature and low-temperature cascade intervals. The tail gas purification path sequentially includes particulate filtration, desulfurization, electrostatic precipitation, and denitrification, which can efficiently remove particulate matter, acidic gases, and heavy metal pollutants therein. The waste heat part realizes energy recovery through a cycle power generation module based on the organic Rankine cycle (ORC), uses a low-boiling-point working fluid to convert low-grade heat energy into electric energy, and improves the overall energy efficiency of the system. The carbon capture and solidification module separates CO2 based on the temperature swing adsorption (TSA) technology, and combines a low-temperature refrigeration process to liquefy and solidify it into dry ice, promoting the high-value utilization of carbon resources. The air dehumidification heat pump module uses a heat pump cycle to dehumidify and heat the combustion air to reduce humidity, slow down equipment corrosion, and improve combustion efficiency.

[0017] 2. By setting four energy storage heat exchangers, the tail gas treatment system differentially sets two heat exchangers with the same heat exchange medium, which can not only accurately match the heat energy characteristics of tail gas in different temperature zones, realize the efficient hierarchical recovery and storage of heat energy from high temperature (about 160 °C) to low temperature (about 80 °C) during the incineration process, improve the overall energy efficiency level of the system, but also realize heat regeneration between the key desulfurization and denitrification links, and further utilize the waste heat additionally generated by the denitrification process on the basis of the waste heat of the incineration tail gas itself, realize the collaborative recovery, coupled utilization, and dynamic regulation of multi-source heat energy, promote the deep purification of tail gas and the closed-loop utilization of energy, and significantly reduce energy consumption and carbon emissions.

[0018] 3. The tail gas treatment system disclosed by the present invention is equipped with sensors at the key parts of the tube side, shell side, energy storage medium of the heat exchanger, and the air dehumidification heat pump module, and designs an intelligent control strategy for the controller to realize an automatic adjustment mechanism. On the one hand, it automatically guides the tail gas to flow into the next module or realizes the energy storage cycle control, avoids waste of heat energy, and ensures the stable operation of the system; on the other hand, it realizes the dual guarantee of the supply air temperature and humidity, ensures that the air sent into the incinerator meets the optimal combustion conditions, and further improves the heat pump operation efficiency and energy utilization rate of the whole system.

[0019] 4. The present invention provides an environmentally friendly, energy-saving, and intelligent tail gas treatment solution, which is applicable to various industrial exhaust gas scenarios with low grade, high humidity, and high pollution, and has broad engineering application prospects.

[0020] 5. The energy storage heat exchanger disclosed by the present invention, through innovative structural design, introduces a gravity sedimentation mechanism, effectively avoids the common pipeline blockage problem in traditional shell-and-tube heat exchangers, realizes the self-cleaning function of the equipment, thereby greatly reducing the maintenance frequency and improving the operation stability and long-term reliability.

[0021] Traditional heat exchangers usually only have the function of heat exchange and cannot achieve energy storage and regulation, resulting in low efficiency in the utilization of low-grade heat energy and serious energy waste. On the basis of heat exchange, the energy storage heat exchanger of the present invention innovatively integrates a cascaded energy storage function, which can store and release heat energy in stages according to the heat source grade and heat demand, significantly improving the recovery and utilization efficiency of low-grade energy. This design effectively breaks the limitation of traditional heat exchangers of "instant heat exchange and inability to store heat", helps to achieve the balanced allocation of energy and the energy-saving optimization of system operation, and meets the development goal of energy conservation and carbon reduction.

[0022] In terms of material selection, when traditional heat exchangers are dealing with corrosive working conditions of high-pollution gases (such as nitrogen and sulfur compounds), they usually need to use expensive duplex stainless steel as a whole or use large-sized and complexly processed fluoroplastic heat exchangers to deal with condensation corrosion problems. However, according to the differences in corrosion risks of each part in the present invention, duplex stainless steel with excellent corrosion resistance is selected for the hot side to effectively resist the erosion of corrosive condensation media; ordinary alloy steel or carbon steel can be reasonably used for the non-hot side parts to reduce material costs and simplify the processing difficulty. This design greatly reduces the manufacturing cost and shrinks the equipment volume while ensuring the overall corrosion resistance and structural strength, demonstrating higher economy, compactness and engineering application value. Brief Description of the Drawings

[0023] Figure 1 It is a process architecture diagram of the sludge incineration tail gas treatment system in the embodiment of the present invention.

[0024] Figure 2 It is a structural schematic diagram of the energy storage heat exchanger in the embodiment of the present invention.

[0025] Figure 3 For Figure 2 an enlarged structural schematic diagram of the energy storage heat exchange tube and the central cylinder in

[0026] Figure 4 It is a schematic diagram of the medium flow directions of the tube side and the shell side of the first energy storage heat exchanger in the embodiment of the present invention.

[0027] Figure 5 It is a schematic diagram of the medium flow directions of the tube side and the shell side of the second energy storage heat exchanger in the embodiment of the present invention.

[0028] Figure 6 It is a schematic diagram of the medium flow directions of the tube side and the shell side of the third energy storage heat exchanger in the embodiment of the present invention.

[0029] Figure 7 It is a schematic diagram of the medium flow directions of the tube side and the shell side of the fourth energy storage heat exchanger in the embodiment of the present invention.

[0030] In the figure: 1. Incinerator; 2. Bag filter; 3. Induced draft fan; 4. Energy storage heat exchanger I; 5. Energy storage heat exchanger II; 6. Desulfurization tower; 7. Electrostatic precipitator; 8. Denitration tower; 9. Energy storage heat exchanger III; 10. Energy storage heat exchanger IV; 11. Carbon capture device; 12. Refrigeration unit; 13. Liquid storage tank; 14. Freezer; 15. Steam turbine; 16. Generator; 17. Regenerator; 18. Exhaust tower; 19. Centrifugal pump; 20. Blower; 21. Compressor; 22. Evaporator; 23. Expansion valve; 24. Condenser; 25. Buffer tank I; 26. On-off valve I; 27. Buffer tank II; 28. On-off valve II; E1. Heat exchanger housing; E11. First through hole; E2. Energy storage heat exchange tube; E20. Interlayer; E21. Reinforcing rib; E3. Central cylinder; E4. Inlet header; E5. Outlet header; E52. Second through hole; E6. Annular gap; E7. Particulate matter discharge port. Detailed implementation manners

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] Please refer to Figures 1 to 3 , this embodiment provides a sludge incineration tail gas treatment system, including: a tail gas purification module, a carbon capture and solidification module, a circulating power generation module, an air dehumidification heat pump module, and a cascaded energy storage module. It may also include a controller (not shown in the figure).

[0033] The tail gas purification module is used to sequentially perform particulate matter filtration, desulfurization, electrostatic precipitation, and denitration on the tail gas discharged from the incinerator 1 at a temperature of 200°C to 250°C, and remove particulate matter (PM), acidic gases (sulfur dioxide, nitrogen oxides), and heavy metal pollutants therein. The tail gas purification module includes a bag filter 2, a desulfurization tower 6, an electrostatic precipitator 7, and a denitration tower 8, which are respectively used for performing particulate matter filtration, desulfurization, electrostatic precipitation, and denitration on the tail gas.

[0034] The sludge is sent into the incinerator 1 for high-temperature combustion. The temperature of the tail gas is about 200 - 250°C. The tail gas contains particulate matter, SO2, NO x , CO2, and heavy metals and other pollutants. The tail gas is transported by the induced draft fan 3 to the bag filter 2 and enters the subsequent purification and waste heat recovery link.

[0035] Among them, the bag filter 2 captures and filters particulate matter through high-efficiency filter media, and can remove more than 90% of the particulate matter in the tail gas. The tail gas after dust removal maintains a relatively high temperature and then enters the energy storage heat exchanger I 4. The desulfurization tower 6 uses a typical wet desulfurization process (such as the limestone-gypsum method) for desulfurization treatment. The SO2 in the tail gas fully reacts with the alkaline components in the desulfurization liquid to generate calcium sulfite or calcium sulfate, achieving the purpose of desulfurization. At this time, the temperature of the tail gas basically remains above 80 °C, which is suitable for subsequent electrostatic dust removal treatment. The denitration tower 8 uses the selective catalytic reduction process for denitration treatment. The tail gas is reheated to above 160 °C and enters the denitration tower 8, where it reacts with a reducing agent (such as ammonia or urea) under the action of a catalyst to x reduce NO to harmless nitrogen (N2) and water, realizing deep purification and ultra-low emission of the tail gas.

[0036] The carbon capture and solidification module is used to collect CO2 in the tail gas through temperature swing adsorption and cryogenic cooling technology, realizing the efficient capture, liquefaction and solidification of CO2. The carbon capture and solidification module includes a carbon capture device 11, a refrigeration unit 12, a liquid storage tank 13 and a freezer 14; among them, the carbon capture device 11 uses temperature swing adsorption technology to drive the adsorbent to selectively adsorb and desorb CO2 at different temperatures. The desorbed CO2 is sent to the refrigeration unit 12 for liquefaction and stored in the liquid storage tank 13. The CO2 is cooled to -78 °C to -80 °C through cryogenic cooling technology and transformed into dry ice form and stored in the freezer 14. In some embodiments, the refrigeration unit 12 can use the electric energy provided by the circulating power generation module.

[0037] The circulating power generation module is used to convert the low-grade waste heat in the tail gas into electric energy through the organic Rankine cycle technology. The circulating power generation module includes a steam turbine 15, a generator 16, a regenerator 17, an exhaust tower 18 and a centrifugal pump 19; among them, the low-boiling working fluid is heated to 150-160 °C in the shell side of the energy storage heat exchanger III 9 and converted into high-pressure steam, and then enters the steam turbine 15 to drive the impeller of the steam turbine 15 to rotate, thereby driving the coupled generator 16 to generate electricity; after the low-boiling working fluid steam loses energy during work, it exchanges waste heat with the cooled tail gas after collecting CO2 through the regenerator 17 to condense into a liquid state, and then is transported back to the shell side of the energy storage heat exchanger III 9 by the centrifugal pump 19, and the tail gas is finally discharged from the exhaust tower 18. In this embodiment, the low-boiling working fluid uses R245fa (pentafluoropropane, boiling point about 15 °C).

[0038] In this embodiment, the electric energy generated by the cyclic power generation module can be used to supply energy to each module inside the system, such as driving the compressor 21, the refrigeration unit 12, sensors, controllers, etc., to form a local energy self - circulation. After the R245fa steam with work - done energy loss exchanges heat with the cooling exhaust gas in the recuperator 17 and condenses into a liquid state, it is transported back to the energy storage heat exchanger three 9 by the centrifugal pump 19, constituting a closed - loop thermodynamic cycle system to achieve efficient reuse of low - grade waste heat.

[0039] The air dehumidification and heat pump module is used to dehumidify and pre - heat the air entering the incinerator 1, improve the combustion efficiency and reduce the moisture content of the exhaust gas. The air dehumidification and heat pump module includes a blower 20, a compressor 21, an evaporator 22, an expansion valve 23, and a condenser 24, which are connected in sequence to form a refrigerant cycle system. The refrigerant sequentially passes through the expansion valve 23, the evaporator 22, the compressor 21, and the condenser 24 to complete the reverse Carnot cycle and exchange heat with the fresh air sent by the blower 20; the air is cooled to 0°C - 10°C in the evaporator 22, which is lower than the dew point temperature, so that water is separated to complete dehumidification, and then heated to 30°C - 50°C in the condenser 24 to achieve pre - heating. In this embodiment, the refrigerant used is R410A.

[0040] The cascade energy storage module is used to hierarchically recover and manage the waste heat in different temperature zones of the exhaust gas during the purification process. The cascade energy storage module includes an energy storage heat exchanger one 4, an energy storage heat exchanger two 5, an energy storage heat exchanger three 9, and an energy storage heat exchanger four 10, and may also include a buffer tank one 25, a switching valve one 26, a buffer tank two 27, and a switching valve two 28.

[0041] The hierarchically stored thermal energy is respectively allocated to the following functional modules for use: the energy storage heat exchanger three 9 provides heat source for the cyclic power generation module; the energy storage heat exchanger four 10 is used to provide heating support for the air dehumidification and heat pump module.

[0042] Among them, the energy storage heat exchanger one 4 is used to cool the exhaust gas after particulate matter filtration treatment to above the first temperature threshold and store high - grade waste heat; the energy storage heat exchanger two 5 is used to cool the exhaust gas cooled by the energy storage heat exchanger one 4 to above the second temperature threshold and store low - grade waste heat; the energy storage heat exchanger one 4 and the energy storage heat exchanger two 5 also use the waste heat stored in themselves to gradually raise the temperature of the exhaust gas after electrostatic precipitation and desulfurization to above the first temperature threshold for denitrification treatment, and the temperature of the exhaust gas rises after denitrification; the energy storage heat exchanger three 9 is used to cool the exhaust gas after denitrification to above the first temperature threshold and store high - grade waste heat, and at the same time use this waste heat to convert the low - boiling - point working fluid in the cyclic power generation module from a liquid state to a steam state; the energy storage heat exchanger four 10 is used to cool the exhaust gas cooled by the energy storage heat exchanger three 9 to above the second temperature threshold and store low - grade waste heat, and at the same time use this waste heat to further heat the air dehumidified and pre - heated by the air dehumidification and heat pump module and send it into the incinerator 1.

[0043] The energy storage media of the first energy storage heat exchanger 4 and the third energy storage heat exchanger 9 are the same, and the energy storage media of the second energy storage heat exchanger 5 and the fourth energy storage heat exchanger 10 are the same. The phase change temperature of the energy storage media of the former two is higher than that of the latter two. In this embodiment, the first energy storage heat exchanger 4 and the third energy storage heat exchanger 9 are filled with NaNO3-KNO3 eutectic salt with a phase change temperature of about 160 °C, and the second energy storage heat exchanger 5 and the fourth energy storage heat exchanger 10 are filled with paraffin-based energy storage materials with a phase change temperature of 80-100 °C, so as to realize the hierarchical storage and release of high-temperature and low-temperature heat energy in the incineration tail gas.

[0044] The first energy storage heat exchanger 4, the second energy storage heat exchanger 5, the third energy storage heat exchanger 9 and the fourth energy storage heat exchanger 10 all adopt the same kind of energy storage heat exchanger, which includes a heat exchanger shell E1 and an energy storage heat exchange tube E2; the energy storage heat exchange tube E2 is a double-layer nested test tube-shaped structure (concentric hollow tube), and its interlayer E20 is filled with an energy storage medium; the top of the energy storage heat exchange tube E2 is closed and the bottom is open, and it is vertically installed on the bottom wall of the heat exchanger shell E1, so as to divide the inner cavity of the heat exchanger shell E1 into a shell side and a tube side. The shell side is used for circulating cold medium (medium that needs to be heated), and the tube side is used for circulating hot medium (medium that needs to be cooled). The energy storage medium is used to absorb the heat in the hot medium and release it to the cold medium.

[0045] The energy storage heat exchanger also includes a central cylinder E3, an inlet header E4 and an outlet header E5; the inlet header E4, the outlet header E5 and the heat exchanger shell E1 are adjacently connected in sequence from bottom to top to form a tower-like structure; a first through hole E11 communicating with the outlet header E5 is opened on the bottom wall of the heat exchanger shell E1, and the size of the first through hole E11 is adapted to the central round hole at the bottom end of the energy storage heat exchange tube E2; the central cylinder E3 is coaxially arranged with the energy storage heat exchange tube E2, the bottom end of the central cylinder E3 is fixedly connected to the bottom wall of the outlet header E5, the top end of the central cylinder E3 extends into the energy storage heat exchange tube E2 through the first through hole E11, and there is a gap between the top end of the central cylinder E3 and the inner wall top end of the energy storage heat exchange tube E2. There is an annular gap E6 between the outer wall of the central cylinder E3 and the inner wall of the energy storage heat exchange tube E2 in the radial direction, so as to form a bent flow path in the tube side of the energy storage heat exchanger; a second through hole E52 communicating with the inlet header E4 is opened on the bottom wall of the outlet header E5, and the size of the second through hole E52 is adapted to the central round hole at the bottom end of the central cylinder E3; a tube side inlet and a tube side outlet are respectively arranged on the opposite side walls of the inlet header E4 and the outlet header E5; a shell side inlet and a shell side outlet are respectively arranged on the opposite side walls of the heat exchanger shell E1, and the height of the shell side inlet can be lower than the height of the shell side outlet, so that the cold medium can fully contact the energy storage heat exchange tube E2 in the shell side. Figure 2 The tube side inlet, the tube side outlet, the shell side inlet and the shell side outlet of the energy storage heat exchanger are also marked respectively.

[0046] There are several energy storage heat exchange tubes E2 in the energy storage heat exchanger, which are arranged in an array on the horizontal plane; reinforcing ribs E21 are also provided in the interlayer E20 of each energy storage heat exchange tube E2; both the outer surface of the central cylinder E3 and the energy storage heat exchange tube E2 are made of duplex stainless steel. The inclination angles of the array distribution of the heat exchange tubes are mainly 30°, 60°, 45° and 90°, and these angles correspond to different arrangement patterns respectively, including equilateral triangle arrangement (30°), corner equilateral triangle arrangement (60°), square arrangement (45°) and corner square arrangement (90°).

[0047] In the present invention, the hot medium (containing particles) flows through the tube side, and the cold medium flows through the shell side; the hot medium enters the inlet header E4 from the tube side inlet, and then is transmitted from the bottom to the top of the central cylinder E3, turns back through the top interval, and then is transmitted from top to bottom through the annular gap E6, enters the outlet header E5, and finally is discharged from the tube side outlet of the heat exchanger. Among them, particulate matter settlement will occur during the upward movement of the hot medium in the central cylinder E3, and the settled particulate matter will be discharged from the particulate matter discharge port at the bottom of the inlet header E5. The cold medium enters the shell side from the shell side inlet of the heat exchanger housing E1, and after passing through several energy storage heat exchange tubes E2, is discharged from the shell side outlet on the other side of the heat exchanger housing E1 to complete heat exchange. The central cylinder E3 is used for particulate matter settlement, the annular gap E6 improves the heat exchange efficiency and prevents blockage, and the energy storage medium in the interlayer is used to absorb and release heat. This design can effectively reduce the blockage risk and improve the stable operation of the heat exchanger.

[0048] According to the transmission direction of the tail gas, the tail gas discharge port of the incinerator 1, the bag filter 2, the induced draft fan 3, the tube side of the first energy storage heat exchanger 4, the tube side of the second energy storage heat exchanger 5, the first buffer tank 25, the first switching valve 26, the desulfurization tower 6, the electrostatic precipitator 7, the shell side of the second energy storage heat exchanger 5, the shell side of the first energy storage heat exchanger 4, the denitration tower 8, the tube side of the third energy storage heat exchanger 9, the tube side of the fourth energy storage heat exchanger 10, the second buffer tank 27, the second switching valve 28, the carbon capture device 11, the regenerator 17 and the exhaust tower 18 are connected in sequence to form a complete tail gas treatment flow path. The specific process is as follows: Please refer to Figure 4 , the tube side inlet of the first energy storage heat exchanger 4 is connected to the air outlet side of the induced draft fan 3, and is used to input the tail gas at 200°C to 250°C that has passed through particulate matter filtration. After heat exchange with the internal energy storage medium, the tube side outlet of the first energy storage heat exchanger 4 outputs the tail gas at a temperature higher than 160°C to the tube side inlet of the second energy storage heat exchanger 5.

[0049] Please refer to Figure 5, after the tail gas above 160°C is input into the tube side inlet of the energy storage heat exchanger II 5, through heat exchange with the internal energy storage working medium, the tube side outlet of the energy storage heat exchanger 5 outputs the tail gas above 80°C to the inlet of the first buffer tank 25. These tail gases are temporarily stored in the first buffer tank 25, and the connection state between the inside of the first buffer tank 25 and the inlet of the desulfurization tower 6 is achieved by controlling the opening and closing of the first switching valve 26. The outlet of the desulfurization tower 6 is connected to the inlet side of the electrostatic precipitator 7. After desulfurization and electrostatic precipitation, the temperature of the tail gas decreases. The outlet side of the electrostatic precipitator 7 is connected to the shell side inlet of the energy storage heat exchanger II 5. The shell side outlet of the energy storage heat exchanger II 5 is connected to the shell side inlet of the energy storage heat exchanger I 4. The shell side outlet of the energy storage heat exchanger I 4 is connected to the inlet of the denitration tower 8. Through the shell sides of the energy storage heat exchanger II 5 and the energy storage heat exchanger I 4, the tail gas is reheated to above 160°C and finally enters the denitration tower 8 to complete selective catalytic reduction (i.e., SCR) denitration treatment. This denitration process releases heat, causing the temperature of the tail gas to rise. In some embodiments, by controlling factors such as the reaction rate of the denitration process, the tail gas entering the energy storage heat exchanger III 9 is within a suitable temperature range (165°C - 185°C) for subsequent recycling.

[0050] Please refer to Figure 6 , the tube side inlet of the energy storage heat exchanger III 9 is connected to the outlet of the denitration tower 8 to exchange heat for the heated tail gas after denitration. The energy storage medium absorbs the waste heat, reducing the temperature of the tail gas to above 160°C; the tube side outlet of the energy storage heat exchanger III 9 is used to output to the tube side inlet of the energy storage heat exchanger IV 10. The shell side inlet of the energy storage heat exchanger III 9 is connected to the outlet of the centrifugal pump 19. The heat absorbed by the energy storage working medium evaporates the liquid R245fa into steam at 150°C - 160°C, which is then sent to the steam turbine 15 for power generation.

[0051] Please refer to Figure 7 , the tube side inlet of the energy storage heat exchanger IV 10 receives the tail gas above 160°C. After heat exchange with its own energy storage medium, the tube side outlet outputs the tail gas above 80°C to the second buffer tank 27. The second buffer tank 27 temporarily stores these tail gases. By controlling the opening and closing of the second switching valve 28, the connection state between the inside of the second buffer tank 27 and the carbon capture device 11 is achieved. The shell side inlet of the energy storage heat exchanger IV 10 receives the air that has been dehumidified and preheated by the air dehumidification and heat pump module. The waste heat in the energy storage medium can heat the air to about 80°C - 90°C, which is then sent to the air inlet of the incinerator 1 to improve the combustion efficiency and reduce the moisture content of the tail gas.

[0052] In this embodiment, temperature sensors are provided at both the tube side inlets and tube side outlets of all energy storage heat exchangers, and flow sensors are provided at either the tube side inlets or tube side outlets of all energy storage heat exchangers for real-time monitoring of the heat side heat exchange parameters; temperature sensors are also provided inside the energy storage media of all energy storage heat exchangers for real-time monitoring of the heat storage state.

[0053] A controller, which is configured to calculate the heat input of the hot side of each energy storage heat exchanger according to the monitoring data collected by the temperature sensor and the flow sensor, and calculate the heat balance deviation value by combining with the target heat absorption of the energy storage medium, so as to make the following control strategies: When the heat balance deviation values of the energy storage heat exchanger 1-4 and the energy storage heat exchanger 2-5 respectively exceed a preset deviation threshold (5%), the control switch valve 1-26 is controlled to open; When the heat balance deviation values of the energy storage heat exchanger 3-9 and the energy storage heat exchanger 4-10 respectively exceed 5%, the control switch valve 2-28 is controlled to open.

[0054] This control strategy can automatically guide the tail gas to flow into the next module or realize the energy storage cycle control, avoid heat energy waste and ensure the stable operation of the system.

[0055] Among them, the heat input of the hot side of the energy storage heat exchanger The calculation formula is: ; In the formula, is the mass flow rate of the tube-side heat medium, is the specific heat capacity of the heat medium, is the temperature difference between the inlet and outlet of the tube-side heat medium, is the monitoring time.

[0056] The target heat absorption of the energy storage medium The calculation formula is: ; In the formula, is the mass of the energy storage medium, is the latent heat of phase change of the energy storage medium, is the specific heat capacity of the energy storage medium, is the temperature difference required to reach the target temperature (above 160 °C or 80 °C); The heat balance deviation value The calculation formula is: .

[0057] In the air dehumidification heat pump module, temperature sensors and humidity sensors are arranged at the shell-side inlet of the evaporator 22 and the shell-side outlet of the condenser 24; a temperature sensor is arranged at the shell-side outlet of the energy storage heat exchanger 4-10.

[0058] In order to improve the dehumidification capacity and energy utilization efficiency of the system, the controller is further configured to calculate the dehumidification amount and dehumidification performance coefficient related to the air dehumidification heat pump module, so as to make the following control strategies: When the temperature at the shell - side outlet of the fourth energy - storage heat exchanger 10 is lower than a preset temperature threshold (80 °C), the rotational speed of the blower 20 is reduced to decrease the air flow rate, extend the residence time of the air in the shell - side of the fourth energy - storage heat exchanger 10, thereby enhancing the degree of air heating and ensuring that the air fed into the incinerator meets the temperature requirements; When the dehumidification capacity is less than a preset target dehumidification capacity the operating frequency of the compressor 21 is adjusted to enhance the cooling output on the evaporator 22 side; When the coefficient of performance of dehumidification is lower than a preset performance evaluation threshold, it indicates that the dehumidification efficiency of the system is low. At this time, the rotational speed of the blower 20 is further controlled to decrease, reducing the mass flow rate of the air, extending the residence time of the air in the evaporator 22, thereby enhancing the dehumidification degree; The coefficient of performance of dehumidification is calculated by the formula: ; In the formula, is the mass flow rate of the air, is the latent heat of condensation of water vapor, is the input power of the air dehumidification heat pump module. It should be noted that when the rotational speed of the blower 20 is decreased, although the mass flow rate of the air decreases, since the amount of moisture removed per unit of air is more significant, the dehumidification latent heat removal amount increases overall, and thus is enhanced.

[0059] This control strategy realizes the dual guarantee of the supply air temperature and humidity, ensures that the air fed into the incinerator meets the optimal combustion conditions, and at the same time improves the heat pump operation efficiency and energy utilization rate of the entire system.

[0060] The above - mentioned is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. A sludge incineration tail gas treatment system, characterized in that, Including: An exhaust gas purification module for successively performing particulate filtration, desulfurization, electrostatic precipitation, and denitrification treatment on the exhaust gas discharged from the incinerator (1); A carbon capture and solidification module for collecting CO2 in the exhaust gas through temperature swing adsorption and cryogenic cooling technologies; A circulating power generation module for converting low-grade waste heat in the exhaust gas into electric energy through an organic Rankine cycle technology; An air dehumidification heat pump module for dehumidifying and preheating the air entering the incinerator (1); A cascaded energy storage module for hierarchically recovering and managing the waste heat in different temperature zones of the exhaust gas; the cascaded energy storage module includes a first energy storage heat exchanger (4), a second energy storage heat exchanger (5), a third energy storage heat exchanger (9), and a fourth energy storage heat exchanger (10); wherein, the first energy storage heat exchanger (4) is used to cool the exhaust gas after particulate filtration treatment to above the first temperature threshold and store high-grade waste heat; the second energy storage heat exchanger (5) is used to cool the exhaust gas cooled by the first energy storage heat exchanger (4) to above the second temperature threshold and store low-grade waste heat; the first energy storage heat exchanger (4) and the second energy storage heat exchanger (5) also use the waste heat stored in themselves to gradually raise the temperature of the exhaust gas after electrostatic precipitation and desulfurization to above the first temperature threshold for denitrification treatment, and the temperature of the exhaust gas rises after denitrification; the third energy storage heat exchanger (9) is used to cool the exhaust gas after denitrification to above the first temperature threshold and store high-grade waste heat, and at the same time use this waste heat to convert the low-boiling working fluid in the circulating power generation module from liquid to steam; the fourth energy storage heat exchanger (10) is used to cool the exhaust gas cooled by the third energy storage heat exchanger (9) to above the second temperature threshold and store low-grade waste heat, and at the same time use this waste heat to further heat the air dehumidified and preheated by the air dehumidification heat pump module and send it into the incinerator (1).

2. The sludge incineration tail gas treatment system according to claim 1, characterized in that, Independent shell passes and tube passes are provided inside all the energy storage heat exchangers. The shell pass is used for circulating cold medium, the tube pass is used for circulating hot medium, and an energy storage medium for absorbing the heat in the hot medium and releasing it to the cold medium is also provided between the shell pass and the tube pass.

3. The sludge incineration exhaust gas treatment system according to claim 2, characterized in that The exhaust gas purification module includes a bag filter (2), a desulfurization tower (6), an electrostatic precipitator (7), and a denitrification tower (8), which are respectively used for performing particulate filtration, desulfurization, electrostatic precipitation, and denitrification treatment on the exhaust gas; the exhaust gas purification module also includes a draft fan (3) for providing power for the exhaust gas transmission; The carbon capture and solidification module includes a carbon capture device (11), a refrigeration unit (12), a liquid storage tank (13), and a cold cabinet (14); wherein, the carbon capture device (11) adopts temperature swing adsorption technology to drive the adsorbent to selectively adsorb and desorb CO2 at different temperatures, and the desorbed CO2 is sent to the refrigeration unit (12) for liquefaction and stored in the liquid storage tank (13), and the CO2 is transformed into dry ice form through cryogenic cooling process and stored in the cold cabinet (14); The cyclic power generation module includes a steam turbine (15), a generator (16), a regenerator (17), an exhaust tower (18) and a centrifugal pump (19); wherein, after the low-boiling-point working fluid is heated and converted into steam in the shell side of the energy storage heat exchanger III (9), it enters the steam turbine (15) to drive the impeller of the steam turbine (15) to rotate, thereby driving the coupled generator (16) to generate electricity; after the low-boiling-point working fluid steam loses energy during work, it exchanges waste heat with the cooled tail gas after collecting CO2 in the regenerator (17) to condense into a liquid state, and then is transported back to the shell side of the energy storage heat exchanger III (9) by the centrifugal pump (19), and the tail gas after waste heat exchange is discharged to the atmosphere by the exhaust tower (18); The air dehumidification heat pump module includes a blower (20), a compressor (21), an evaporator (22), an expansion valve (23), and a condenser (24), which are connected in sequence to form a refrigerant circulation system. The refrigerant sequentially passes through the expansion valve (23), the evaporator (22), the compressor (21), and the condenser (24) to complete the reverse Carnot cycle and exchange heat with the fresh air sent by the blower (20); the air is cooled to below the dew point temperature in the evaporator (22), thereby separating water to complete dehumidification, and then preheated through the condenser (24).

4. A sludge incineration tail gas treatment system according to claim 3, characterized in that, The cascade energy storage module further includes a buffer tank I (25), a switching valve I (26), a buffer tank II (27) and a switching valve II (28); Among them, in the direction of the tail gas transmission, the tail gas discharge port of the incinerator (1), the bag filter (2), the induced draft fan (3), the tube side of the energy storage heat exchanger I (4), the tube side of the energy storage heat exchanger II (5), the buffer tank I (25), the switching valve I (26), the desulfurization tower (6), the electrostatic precipitator (7), the shell side of the energy storage heat exchanger II (5), the shell side of the energy storage heat exchanger I (4), the denitration tower (8), the tube side of the energy storage heat exchanger III (9), the tube side of the energy storage heat exchanger IV (10), the buffer tank II (27), the switching valve II (28), the carbon capture device (11), the regenerator (17) and the exhaust tower (18) are connected in sequence to form a complete tail gas treatment flow path.

5. A sludge incineration tail gas treatment system according to claim 4, characterized in that, Temperature sensors are provided at the inlet and outlet of the tube side of all energy storage heat exchangers, and temperature sensors are also provided inside the energy storage media of all energy storage heat exchangers; flow sensors are also provided in the tube side of all energy storage heat exchangers; The sludge incineration tail gas treatment system further includes: A controller, which is used to calculate the heat input of the hot side of each energy storage heat exchanger according to the monitoring data collected by the temperature sensors and flow sensors, and combine the target heat absorption of the energy storage medium to calculate the heat balance deviation value, thereby making the following control strategies: When the heat balance deviation values of the energy storage heat exchanger I (4) and the energy storage heat exchanger II (5) both exceed a preset deviation threshold, control the switching valve I (26) to open; When the heat balance deviation values of the energy storage heat exchanger III (9) and the energy storage heat exchanger IV (10) both exceed the deviation threshold, control the switching valve II (28) to open; Among them, the heat input of the hot side of the energy storage heat exchanger is calculated by the following formula: ； In the formula, is the mass flow rate of the hot medium in the tube side, is the specific heat capacity of the hot medium, is the temperature difference between the inlet and outlet of the hot medium in the tube side, is the monitoring time; Target heat absorption of energy storage medium The calculation formula is as follows: ； In the formula, is the mass of the energy storage medium, is the latent heat of phase change of the energy storage medium, is the specific heat capacity of the energy storage medium, is the temperature difference required to reach the target temperature; Thermal balance deviation value The calculation formula is as follows: 。 6. The sludge incineration tail gas treatment system according to claim 5, characterized in that, In the air dehumidification heat pump module, temperature sensors and humidity sensors are provided at both the inlet of the shell side of the evaporator (22) and the outlet of the shell side of the condenser (24); a temperature sensor is provided at the outlet of the shell side of the energy storage heat exchanger four (10). The controller is further configured to calculate the dehumidification amount and the dehumidification performance coefficient related to the air dehumidification heat pump module, and thus make the following control strategies: When the temperature at the outlet of the shell side of the energy storage heat exchanger four (10) is lower than a preset temperature threshold, the controller controls the rotational speed of the blower (20) to decrease, so as to reduce the mass flow rate of the air, extend the residence time of the air in the shell side of the energy storage heat exchanger four (10), and thereby enhance the heating degree of the air. When the dehumidification amount is less than a preset target dehumidification amount, the working frequency of the compressor (21) is adjusted to enhance the cold output on the evaporator (22) side. When the dehumidification performance coefficient is lower than a preset performance evaluation threshold, the rotational speed of the blower (20) is controlled to decrease to reduce the mass flow rate of air and extend the residence time of the air in the evaporator (22), thereby enhancing the dehumidification degree; wherein, the dehumidification capacity is calculated by the formula: ； wherein, and are the absolute moisture contents of the air at the inlet of the shell side of the evaporator (22) and the outlet of the shell side of the condenser (24) respectively, with the unit of kg water / kg dry air; Coefficient of dehumidification performance The calculation formula is as follows: ； In the formula, is the mass flow rate of air, is the latent heat of condensation of water vapor, is the input power of the air dehumidification heat pump module.

7. A sludge incineration tail gas treatment system according to claim 1, characterized in that, In the tail gas purification module, a wet process is used for desulfurization treatment, and a selective catalytic reduction process is used for denitrification treatment.

8. A energy storage heat exchanger, characterized in that, Applied to a sludge incineration tail gas treatment system according to any one of claims 1 to 7; the energy storage heat exchanger includes a heat exchanger housing (E1) and energy storage heat exchange tubes (E2); the energy storage heat exchange tubes (E2) are of a double-layer nested test tube-like structure, and a energy storage medium is filled in the interlayer (E20) thereof; the top end of the energy storage heat exchange tube (E2) is closed and the bottom end is open, and it is vertically installed on the bottom wall of the heat exchanger housing (E1), thereby dividing the inner cavity of the heat exchanger housing (E1) into a shell side and a tube side.

9. The energy storage heat exchanger according to claim 8, characterized in that, The energy storage heat exchanger further includes a central cylinder (E3), an inlet header (E4) and an outlet header (E5); the inlet header (E4), the outlet header (E5) and the heat exchanger housing (E1) are adjacently arranged in sequence from bottom to top to form a tower-like structure; a first through hole (E11) communicating with the outlet header (E5) is formed in the bottom wall of the heat exchanger housing (E1), and the size of the first through hole (E11) is adapted to the central circular hole at the bottom end of the energy storage heat exchange tube (E2); the central cylinder (E3) is coaxially arranged with the energy storage heat exchange tube (E2), the bottom end of the central cylinder (E3) is fixedly connected to the bottom wall of the outlet header (E5), the top end of the central cylinder (E3) extends into the energy storage heat exchange tube (E2) through the first through hole (E11), and there is a gap between the top end of the central cylinder (E3) and the inner wall top end of the energy storage heat exchange tube (E2), and there is an annular gap (E6) between the outer wall of the central cylinder (E3) and the inner wall of the energy storage heat exchange tube (E2) in the radial direction, thereby forming a bent flow path in the tube side of the energy storage heat exchanger; a second through hole (E52) communicating with the inlet header (E4) is formed in the bottom wall of the outlet header (E5), and the size of the second through hole (E52) is adapted to the central circular hole at the bottom end of the central cylinder (E3); a tube side inlet and a tube side outlet are respectively provided on the opposite side walls of the inlet header (E4) and the outlet header (E5); a shell side inlet and a shell side outlet are respectively provided on the opposite side walls of the heat exchanger housing (E1), and the height of the shell side inlet is lower than the height of the shell side outlet.

10. The energy storage heat exchanger according to claim 9, characterized in that, A number of energy storage heat exchange tubes (E2) in the energy storage heat exchanger are arranged in an array on a horizontal plane; reinforcing ribs (E21) are further arranged in the interlayer (E20) of each energy storage heat exchange tube (E2); the outer surfaces of the central cylinder (E3) and the energy storage heat exchange tubes (E2) are both made of duplex stainless steel; among them, the energy storage media of the first energy storage heat exchanger (4) and the third energy storage heat exchanger (9) are the same, the energy storage media of the second energy storage heat exchanger (5) and the fourth energy storage heat exchanger (10) are the same, and the phase change temperature of the energy storage media of the former two is higher than that of the latter two.

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