Garbage incineration flue gas temperature control and waste heat recovery system based on dry deacidification

Abstract

The utility model relates to a kind of garbage incineration flue gas temperature control and waste heat recovery system based on dry deacidification, belong to garbage incineration flue gas field, comprising: steam turbine, with the steam export intercommunication of waste heat boiler;Phase change heat exchanger, main body is arranged in waste heat boiler export flue, including the heat exchange of flue gas discharged with waste heat boiler evaporative heat exchange section and the condensation heat exchange section located evaporative heat exchange section top and with the heat exchange of condensate water discharged by steam turbine, phase change working medium in the phase change heat exchanger carries out phase change circulation in heat exchange pipe: absorption flue gas heat and evaporate into gaseous state, condense into liquid state after releasing heat to condensate water;Pressure pump, set in condensate water branch pipeline, lead out condensate water and pressurized introduction phase change heat exchanger's condensation heat exchange section carries out heat exchange, to solve the low deacidification efficiency, flue gas waste heat recovery rate low and low temperature corrosion problem caused by flue gas fluctuation in traditional dry deacidification process.

Description

Technical Field

[0001] In the field of waste incineration flue gas treatment technology, specifically, a waste incineration flue gas temperature control and waste heat recovery system based on dry deacidification is involved. Background Technology

[0002] In waste incineration, dry deacidification has gradually gained attention due to its advantages such as low cost and simple operation. Its main principle is to use alkaline substances such as quicklime powder and sodium bicarbonate to neutralize acidic gases in flue gas, generating solid neutral salts. In subsequent processes, the generated solid products are captured by a dust collector, thereby achieving the purpose of removing acidic substances from the flue gas.

[0003] However, achieving efficient operation of this process faces the following technical challenges: Firstly, the narrow reaction temperature window. Dry acid removal is a gas-solid heterogeneous reaction, and its efficiency depends on the flue gas temperature, which is around 150℃. However, the flue gas temperature of existing waste incineration waste heat boilers is generally above 190℃, creating a cooling requirement of approximately 40℃. How to accurately and stably reduce the high flow rate and fluctuating composition of the flue gas from above 190℃ to around 150℃, while overcoming the flue gas volume and temperature fluctuations caused by unstable waste combustion conditions, presents a significant process control challenge.

[0004] Currently, the most common cooling methods are water spray cooling and direct heat exchange cooling. Water spray cooling involves first cooling the flue gas from the waste heat boiler outlet by spraying water through a spray tower before it enters the dry reactor for dry acid removal. The flue gas, cooled from 190℃ to 150℃, contains considerable low-temperature waste heat. The simple water spray cooling method directly wastes this waste heat, contradicting the overall goal of energy conservation and emission reduction. Furthermore, the temperature difference control of water spray cooling is only ±10℃, which cannot guarantee the optimal reaction conditions for dry acid removal. Direct heat exchange cooling typically recovers waste heat from the flue gas directly through a heat exchanger, lowering the flue gas temperature. While this achieves the purpose of recovering waste heat, waste incineration flue gas contains acidic gases such as SO3 and HCl, with an acid dew point temperature generally around 130℃, while dry acid removal requires a flue gas temperature of around 150℃. Using a direct heat exchanger, to ensure a heat exchange difference, the temperature of the cooling medium must be significantly lower than the target flue gas temperature. This makes it very easy for the temperature of the metal wall at the cold end of the heat exchanger to fall below the acid dew point of the flue gas, resulting in low-temperature corrosion, which in turn leads to a sharp reduction in equipment life, an increased risk of leakage, and high maintenance and replacement costs.

[0005] In summary, current dry desulfurization processes face technical challenges in flue gas treatment, including difficulty in accurately and stably controlling flue gas temperature, low-temperature waste heat recovery rate, and unavoidable low-temperature corrosion of heat exchange equipment. Therefore, this invention provides a waste incineration flue gas temperature control and waste heat recovery system based on dry desulfurization to solve the aforementioned technical problems. Summary of the Invention

[0006] In view of this, the purpose of this utility model is to provide a waste incineration flue gas temperature control and waste heat recovery system based on dry desulfurization, so as to solve the problems of insufficient flue gas temperature stability, low flue gas waste heat recovery rate and equipment corrosion in traditional dry desulfurization processes.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A waste incineration flue gas temperature control and waste heat recovery system based on dry acid removal includes:

[0009] The steam turbine is connected to the steam outlet of the waste heat boiler;

[0010] The phase change heat exchanger is arranged in the outlet flue of the waste heat boiler. It includes an evaporation heat exchange section that exchanges heat with the flue gas discharged from the waste heat boiler and a condensation heat exchange section located above the evaporation heat exchange section that exchanges heat with the condensate discharged from the turbine. The phase change working fluid in the phase change heat exchanger undergoes a phase change cycle in the heat exchange tube: it absorbs heat from the flue gas and evaporates into a gaseous state, releases heat to the condensate, and then condenses into a liquid state.

[0011] The condensate pump drives the flow of condensate after passing through the steam turbine;

[0012] A booster pump is installed in the condensate branch pipeline to draw out condensate and pressurize it before introducing it into the condensation heat exchange section of the phase change heat exchanger for heat exchange.

[0013] Furthermore, it also includes a deaerator connected to the condensation heat exchange section of the phase change heat exchanger and collecting and utilizing the heated condensate.

[0014] Furthermore, the outlet flue of the evaporation heat exchange section is equipped with a temperature detector to detect the temperature of the flue gas after passing through the evaporation heat exchange section; the inlet and outlet flues of the evaporation heat exchange section are equipped with pressure detectors to detect the resistance of the flue gas flow through the evaporation heat exchange section; and the outlet condensate pipe of the condensation heat exchange section is equipped with a temperature detector to detect the temperature of the condensate after passing through the condensation heat exchange section.

[0015] Furthermore, the booster pump is a variable frequency pump that controls the condensate flow rate or a fixed frequency pump with a regulating valve circuit.

[0016] Furthermore, the phase change working fluid in the phase change heat exchanger is demineralized water.

[0017] Furthermore, the working pressure of the phase change medium in the phase change heat exchanger is 0.1-0.3 MPa (g).

[0018] Furthermore, the working pressure of the phase change medium in the phase change heat exchanger is 0.2-0.3 MPa (g).

[0019] Based on the same inventive concept, this utility model also provides a method for temperature control and waste heat recovery of waste incineration flue gas based on dry deacidification, including using the above-mentioned waste incineration flue gas temperature control and waste heat recovery system to control the temperature of flue gas from the waste heat boiler and recover waste heat in the waste incineration process.

[0020] Furthermore, the steps for temperature control and waste heat recovery of the flue gas from the waste heat boiler are as follows:

[0021] Step S1: The flue gas from the waste heat boiler enters the evaporation heat exchange section of the phase change heat exchanger through the flue outlet and exchanges heat with the liquid phase change working fluid. After the flue gas is cooled, it enters the dry reactor for dry deacidification. The liquid phase change working fluid absorbs the heat from the flue gas and then vaporizes into a gaseous state.

[0022] In step S2, the low-temperature condensate discharged from the steam turbine flows through the condensation heat exchange section of the phase change heat exchanger under the power of the pressurized pump and exchanges heat with the gaseous phase change working fluid. The low-temperature condensate absorbs heat and rises in temperature, while the gaseous phase change working fluid releases heat to the condensate and then condenses into a liquid state.

[0023] During this process, the flow rate of condensate flowing through the condensation heat exchange section of the phase change heat exchanger is adjusted to control the temperature of the flue gas entering the dry reactor and maintain the optimal reaction conditions for dry acid removal.

[0024] Furthermore, in step S2, the condensate that has absorbed heat and been heated returns to the deaerator and enters the boiler feedwater system.

[0025] The beneficial effects of this utility model are as follows:

[0026] Based on the flue gas temperature of the waste heat boiler in waste incineration and the suitable flue gas temperature required to be maintained in dry acid removal treatment, this utility model configures a phase change heat exchanger at the flue outlet of the waste heat boiler to cool the flue gas, so that the flue gas can reach the suitable temperature required to be maintained in dry acid removal treatment after cooling, thus providing the optimal reaction conditions for the dry acid removal process.

[0027] Furthermore, this invention employs a phase change heat exchanger to heat the condensate discharged from the turbine, thereby transferring the waste heat of the flue gas to the condensate. This not only effectively recovers and utilizes the waste heat of the flue gas, reducing heat loss and waste and improving energy efficiency, but also allows for convenient control of the flue gas temperature after heat exchange by controlling the flow rate of the condensate passing through the condensation heat exchange section. This achieves precise control of the flue gas temperature and effectively reduces flue gas temperature fluctuations during dry acid removal.

[0028] In a phase change heat exchanger, the phase change working fluid absorbs heat and vaporizes in the evaporation heat exchange section, changing from a liquid to a gaseous state. In the condensation heat exchange section, it releases heat and liquefies, changing from a gaseous state to a liquid state, forming a closed-loop cycle. This reduces heat loss and avoids contamination and waste of the phase change working fluid. Furthermore, the phase change heat transfer intensity is much greater than the sensible heat transfer intensity, maintaining high heat transfer efficiency with a small heat exchange terminal temperature difference, while also reducing the heat exchange area and lowering equipment investment.

[0029] The phase change working fluid working pressure of the phase change heat exchanger is adjustable (the higher the pressure, the higher the phase change temperature), which can ensure that the heat exchange tube wall temperature of the evaporation heat exchange section is higher than the acid dew point of the flue gas, avoid low-temperature corrosion, improve the service life of the equipment, and reduce the cost of equipment maintenance and replacement.

[0030] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0031] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0032] Figure 1 This is a schematic diagram of a waste incineration flue gas temperature control and waste heat recovery system based on dry deacidification disclosed in this embodiment.

[0033] Figure reference numerals: 1-Waste heat boiler, 2-Phase change heat exchanger, 201-Evaporation heat exchange section, 202-Condensation heat exchange section, 3-Dry reactor, 4-Bag filter, 5-Induced draft fan, 6-Chimney, 7-Steam turbine, 8-Condensate pump, 9-Deaerator, 10-Feed water pump, 11-Pressure pump. Detailed Implementation

[0034] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0035] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0036] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0037] Please see Figure 1 This is a waste incineration flue gas temperature control and waste heat recovery system based on dry acid removal. It includes a phase changer 2 located in the outlet flue of a waste heat boiler 1 and a steam turbine 7 connected to the steam outlet of the waste heat boiler 1. The flue gas from the waste heat boiler 1 is discharged from the flue outlet, cooled after heat exchange in the phase changer 2, and then passes through a dry reactor 3 to remove acidic substances and a bag filter 4 for dust removal before being discharged into the air through an induced draft fan 5 into a chimney 6 by air, achieving qualified emissions. Steam from the waste heat boiler 1 is discharged from the steam outlet. When it passes through the steam turbine 7, its internal energy is converted into the internal energy of the turbine rotor and released heat, condensing into liquid condensate. The condensate enters the deaerator under the power of the condensate pump 8. Part of the condensate is led out through the branch pipe and pressurized by the booster pump 11 and introduced into the phase change heat exchanger 2. After heat exchange in the phase change heat exchanger 2, the temperature rises and finally flows into the deaerator 9. After deaeration, it is fed into the waste heat boiler 1 by the feed water pump 10 for recycling.

[0038] The phase change heat exchanger 2 includes an evaporation heat exchange section 201 located on the flue gas side and a condensation heat exchange section 202 located above the evaporation heat exchange section 201 and capable of exchanging heat with condensate. In the evaporation heat exchange section 201, the liquid phase change working fluid exchanges heat with the high-temperature flue gas, causing the flue gas temperature to decrease. The liquid phase change working fluid absorbs heat from the flue gas and vaporizes into a gaseous state, rising to the condensation heat exchange section 202. In the condensation heat exchange section 202, the gaseous phase change working fluid exchanges heat with the low-temperature condensate. The gaseous phase change working fluid releases heat to the condensate and condenses into a liquid state, descending back to the evaporation heat exchange section 201. The condensate is then heated and flows into the deaerator 9. In this process, the phase change working fluid absorbs heat and vaporizes in the evaporation heat exchange section 201, changing from a liquid to a gaseous state, and releases heat and liquefies in the condensation heat exchange section 202, changing from a gaseous state to a liquid state, forming a closed-loop cycle.

[0039] In this embodiment, a temperature detector is installed at the outlet of the flue gas through the evaporation heat exchange section 201 to detect the temperature of the flue gas after heat exchange. A variable frequency water pump with variable frequency control is used as a booster pump 11 to control the flow rate of condensate water flowing through the condensation heat exchange section 202. Obviously, the larger the condensate flow rate, the more heat is removed during the heat exchange process, resulting in a lower flue gas outlet temperature. For example, if the temperature detector detects that the flue gas temperature is higher than the set value, the pump frequency can be increased to increase the condensate flow rate, thereby enhancing the heat exchange in the condensation section 202, causing more gaseous working fluid to be condensed, thus enhancing the heat absorption capacity of the evaporation heat exchange section 201, and ultimately leading to a decrease in flue gas temperature, and vice versa. Using an active control loop that coordinates the temperature detector and the variable frequency booster pump 11, the heat exchange rate of the flue gas is precisely controlled by adjusting the condensate flow rate, thereby achieving dynamic balance and high-precision control of the outlet flue gas temperature, providing optimal reaction conditions for the subsequent dry desulfurization in the dry reactor 3.

[0040] Taking a waste incineration plant as an example, the flue gas emission from the waste heat boiler 1 is 100,000 Nm³. 3 With a flue gas volume of / h and an emission temperature of 210℃, and a suitable humidity of 150℃ for the flue gas in dry reactor 3, the flue gas temperature needs to be reduced from 210℃ to 150℃. The waste heat recovery is calculated as follows:

[0041] Basic parameters: Flue gas volume: 100,000 Nm 3 / h; Cooling range: 210℃→150℃, i.e., temperature drop ΔT=60℃; Average specific heat capacity of flue gas under standard conditions: 1.38kJ / (Nm³) 3 •℃); Operating time: calculated at 8000 hours / year.

[0042] Waste heat recovery amount: Q = flue gas volume × specific heat capacity × temperature drop; that is:

[0043] 100000Nm 3 / h×1.38kJ / (Nm 3·℃)×60℃=8280000kJ / h≈2300kW

[0044] However, the actual recovery efficiency needs to take into account the 90% waste heat recovery efficiency of the phase change heat exchanger, and the fluctuation of flue gas composition will cause the specific heat capacity to change by ±5%. At the same time, the self-consumption of each device accounts for 20%, and the actual effective heat recovery is about 1500kW.

[0045] The annual waste heat recovery is: 1500kW × 8000h = 12,000,000kWh / year.

[0046] Converted to standard coal: Based on 1 kWh ≈ 0.1229 kgce, the annual energy saving = 12,000,000 × 0.1229 / 1000 ≈ 1475 tons of standard coal / year.

[0047] As can be seen, the phase change heat exchanger 2 not only cools the flue gas from the waste heat boiler 1, maintaining its temperature within the suitable range for dry acid removal, but also absorbs and transfers heat from the flue gas to the condensate through the phase change circulation of the working fluid within the phase change heat exchanger 2. This effectively recovers and utilizes the waste heat from the flue gas of the waste heat boiler 1, significantly reducing heat loss and waste and improving energy efficiency. The system enables precise flue gas temperature control and waste heat recovery, making the waste incineration flue gas temperature control and waste heat recovery system based on dry acid removal disclosed in this embodiment particularly suitable for scenarios requiring stable flue gas temperature in dry acid removal processes.

[0048] By embedding the phase changer 2 as an energy transfer hub into the two originally independent large systems of dry acid removal flue gas treatment and feedwater heating system, cross-system coupling and efficient utilization of energy are achieved. This not only physically isolates the corrosive flue gas from the low-temperature cooling medium, solving the low-temperature corrosion problem, but also transforms the control of flue gas temperature into the control of condensate flow, solving the temperature control challenge. Ultimately, it achieves a perfect balance of heat recovery, stable temperature control, and prevention of low-temperature corrosion.

[0049] In one possible embodiment, a fixed-frequency water pump with a regulating valve circuit is installed in the condensate branch to replace the variable frequency water volume regulation function of the booster pump 11. The water volume of condensate is controlled through the regulating valve circuit, which can achieve the purpose of regulating the flue gas temperature with lower equipment and maintenance costs.

[0050] In one possible embodiment, the phase change working fluid in phase change heat exchanger 2 is demineralized water. Water has a latent heat of vaporization of 2250 kJ / kg, resulting in high heat transfer intensity per unit working fluid. This allows for maintaining high heat transfer efficiency even with a small heat exchange terminal temperature difference, while also reducing the heat exchange area and lowering equipment investment. Furthermore, in pressure regulation, higher pressure leads to higher phase change temperature. This leverages the high latent heat of vaporization and adjustable phase change temperature of water for heat exchange with flue gas and condensate. Phase change heat exchanger 2 utilizes the latent heat of vaporization of water for heat transfer. Since latent heat is much greater than sensible heat, this means that the required flow rate and temperature difference of the phase change working fluid for transferring large amounts of heat are small, resulting in extremely high heat transfer efficiency. After the heat from the flue gas is absorbed by the working fluid, it is transferred almost without loss to the condensate on the other side, feeding it back to the boiler system. This directly improves the overall thermal efficiency of the boiler system, achieving closed-loop energy recovery.

[0051] In one possible embodiment, the working pressure of the phase change medium in the phase change heat exchanger 2 is 0.1-0.3 MPa(g) to adapt to different equipment environments, with 0.2-0.3 MPa(g) being preferable for harsh flue gas heat exchange scenarios. Since the acid dew point of waste incineration flue gas is generally around 130°C, while the saturation temperature of water at 0.2 MPa(g) is 133.5°C and at 0.3 MPa(g) is 143.6°C, the working pressure of the water is between 0.2 and 0.3 MPa(g). The pressure (Pa(g)) ensures that the phase change medium temperature is maintained between 133.5 and 143.6℃, ​​thereby ensuring that the heat exchange tube wall temperature of the evaporation heat exchange section 201 is higher than the acid dew point of the flue gas, avoiding low-temperature corrosion, extending equipment lifespan, and reducing equipment maintenance and replacement costs. It is worth noting that the pressure mentioned here is gauge pressure. When comparing water pressure with saturation temperature, the absolute pressure must be used. Absolute pressure is the sum of gauge pressure and atmospheric pressure, which is typically 0.10133 MPa. Traditional heat exchanger wall temperatures are determined by the inlet hot and cold fluid temperatures, making them difficult to control. However, the heat exchange section of the phase change heat exchanger 2 acts as a natural thermostat. As long as the phase change medium's operating pressure is stable, the evaporation temperature of the phase change medium is constant. For example, at a pressure of 0.3 MPa, the water saturation temperature remains constant at 143.6℃. Therefore, by employing phase change heat exchange technology and adjusting the working pressure of the phase change medium, the metal wall temperature of the heat exchange tubes in the evaporation heat exchange section 201 can be ensured to remain above the acid dew point of the flue gas, fundamentally eliminating the low-temperature condensation of sulfuric acid vapor and effectively avoiding the technical challenge of low-temperature corrosion in heat exchange equipment. Furthermore, this is a proactive and fundamental anti-corrosion design method, distinct from traditional passive corrosion-resistant material solutions, offering lower costs and more thorough results.

[0052] Based on the same inventive concept, another embodiment of this utility model provides a method for temperature control and waste heat recovery of waste incineration flue gas based on dry deacidification. This method includes using the waste incineration flue gas temperature control and waste heat recovery system described in the above embodiment to control the temperature of the flue gas from the waste heat boiler 1 and recover waste heat during waste incineration. The steps are as follows:

[0053] In step S1, the flue gas from the waste heat boiler 1 enters the evaporation heat exchange section 201 of the phase change heat exchanger 2 through the flue outlet and exchanges heat with the liquid phase change working fluid. After the flue gas is cooled down, it enters the dry reactor 3 for dry deacidification. The liquid phase change working fluid absorbs the heat from the flue gas and is vaporized from liquid to gas, and rises to the condensation heat exchange section 202.

[0054] In step S2, some of the low-temperature condensate discharged from the turbine 7 is drawn out through a branch pipe and flows through the condensation heat exchange section 202 of the phase change heat exchanger 2 under the power drive of the pressurization pump 11. It exchanges heat with the gaseous phase change working fluid. After absorbing heat and rising in temperature, the low-temperature condensate returns to the deaerator 9 and is introduced into the waste heat boiler 1 by the feed water pump 10. The gaseous phase change working fluid releases heat to the condensate and then condenses from the gaseous state to the liquid state, and descends to the evaporation heat exchange section 201.

[0055] During this process, the temperature of the cooled flue gas is obtained by a temperature detector, and the flow rate of condensate flowing through the condensation heat exchange section 202 is controlled by a variable frequency pump 11 or a pressure pump 11 with a regulating valve circuit to regulate the flue gas temperature entering the dry reactor 3.

[0056] This embodiment utilizes the constant temperature characteristics of the phase change heat exchanger 2 to lay the foundation for stability and corrosion prevention. Then, by adjusting the feedback control of the condensate flow rate, precise fine-tuning is achieved. Finally, the triple goals of heat recovery, precise temperature control and long-term corrosion prevention are achieved in synergy.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A waste incineration flue gas temperature control and waste heat recovery system based on dry acid removal, characterized in that, include: The steam turbine is connected to the steam outlet of the waste heat boiler; The phase change heat exchanger is arranged in the outlet flue of the waste heat boiler. It includes an evaporation heat exchange section that exchanges heat with the flue gas discharged from the waste heat boiler and a condensation heat exchange section located above the evaporation heat exchange section that exchanges heat with the condensate discharged from the turbine. The phase change working fluid in the phase change heat exchanger undergoes a phase change cycle in the heat exchange tube: it absorbs heat from the flue gas and evaporates into a gaseous state, releases heat to the condensate, and then condenses into a liquid state. The condensate pump drives the flow of condensate after passing through the steam turbine; A booster pump is installed in the condensate branch pipeline to draw out condensate and pressurize it before introducing it into the condensation heat exchange section of the phase change heat exchanger for heat exchange.

2. The waste incineration flue gas temperature control and waste heat recovery system based on dry deacidification as described in claim 1, characterized in that: It also includes a deaerator that is connected to the condensation heat exchange section of the phase change heat exchanger and collects and utilizes the heated condensate.

3. A waste incineration flue gas temperature control and waste heat recovery system based on dry deacidification as described in claim 1 or 2, characterized in that: The outlet flue of the evaporation heat exchange section is equipped with a temperature detector to detect the temperature of the flue gas after passing through the evaporation heat exchange section; the inlet and outlet flues of the evaporation heat exchange section are equipped with pressure detectors to detect the resistance of the flue gas flow through the evaporation heat exchange section; the outlet condensate pipe of the condensation heat exchange section is equipped with a temperature detector to detect the temperature of the condensate after passing through the condensation heat exchange section.

4. The waste incineration flue gas temperature control and waste heat recovery system based on dry deacidification according to claim 3, characterized in that: The booster pump is a variable frequency pump that controls the condensate flow rate or a fixed frequency pump with a regulating valve circuit.

5. A waste incineration flue gas temperature control and waste heat recovery system based on dry deacidification as described in any one of claims 1, 2, and 4, characterized in that: The phase change working fluid in the phase change heat exchanger is demineralized water.

6. A waste incineration flue gas temperature control and waste heat recovery system based on dry deacidification as described in claim 5, characterized in that: The working pressure of the phase change medium in the phase change heat exchanger is 0.1-0.3 MPa (g).

7. A waste incineration flue gas temperature control and waste heat recovery system based on dry deacidification as described in claim 5, characterized in that: The working pressure of the phase change medium in the phase change heat exchanger is 0.2-0.3 MPa (g).

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