Horizontal flue gas total heat recovery integrated device and control method thereof

Abstract

The invention discloses a horizontal flue gas total heat recovery integrated device and a control method thereof. The device comprises a shell, a sensible heat recovery module, a latent heat recovery module, a flue gas bypass module and a control system, the flue gas bypass module comprises a bypass flue and a switching valve group, the bypass flue is communicated with a flue gas inlet and an inlet of the latent heat recovery module, and / or communicated with an outlet of the sensible heat recovery module and a flue gas outlet, and the switching valve group is communicated with the bypass flue. The switching valve group can selectively guide flue gas to flow through the sensible heat recovery module and / or the latent heat recovery module or guide the flue gas to bypass at least one recovery module through the bypass flue, and the control system is in signal connection with the switching valve group and the recovery modules. Through the modular horizontal structure capable of switching the flue gas path and intelligent cooperative control, efficient cooperative or independent recovery of sensible heat and latent heat is achieved, the flue gas working condition is dynamically adapted, the heat recovery efficiency is remarkably improved, the system energy consumption and maintenance cost are reduced, and pollutant removal is cooperatively enhanced.

Description

Technical Field

[0001] This invention relates to the fields of waste incineration power generation and industrial flue gas treatment and waste heat recovery technology, and particularly to a horizontal integrated flue gas total heat recovery device and its control method. Background Technology

[0002] The flue gas emitted from waste-to-energy plants contains a large amount of sensible and latent heat, along with dust, SO2, and NO. x The urgent need for waste heat recovery and environmental treatment of pollutants such as flue gas is evident. Among related technologies, single sensible or latent heat recovery devices have limited efficiency, failing to fully utilize flue gas energy and resulting in energy waste. Traditional integrated devices are structurally dispersed, occupy large areas, and have high pipeline laying costs and flow resistance. Insufficient gas-liquid contact leads to low heat and mass transfer efficiency, easily causing equipment corrosion and blockage. They lack flexible and intelligent operation mode switching functions, failing to adapt to dynamic changes in flue gas temperature, humidity, and pollutant concentration. Most devices exhibit poor synergy between heat recovery and purification functions, making it difficult to balance environmental benefits and energy utilization efficiency. The flue gas flow path is fixed, still flowing through unnecessary modules in a single mode, resulting in excessively long paths, increased resistance, and reduced lifespan of non-working modules. Operational control strategies are crude, based only on rough operating condition divisions, lacking AI-powered intelligent optimization capabilities based on real-time big data, resulting in insufficient control precision and energy efficiency. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art.

[0004] To this end, embodiments of the present invention propose a horizontal flue gas total heat recovery integrated device. Through a modular horizontal structure with switchable flue gas paths and intelligent collaborative control, it achieves efficient collaborative or independent recovery of sensible heat and latent heat, dynamically adapts to flue gas operating conditions, significantly improves heat recovery efficiency, reduces system energy consumption and maintenance costs, and collaboratively enhances pollutant removal.

[0005] The horizontal flue gas total heat recovery integrated device of this invention includes a shell, a sensible heat recovery module, a latent heat recovery module, a flue gas bypass module, and a control system. The shell has a flue gas inlet and a flue gas outlet. The sensible heat recovery module is located inside the shell and is used for indirect heat exchange with the flue gas to recover sensible heat. The latent heat recovery module is located inside the shell and downstream of the sensible heat recovery module, and is used for direct contact heat exchange with the flue gas to recover latent heat. The latent heat recovery module and the sensible heat recovery module are arranged horizontally at intervals. The flue gas bypass module includes components located in… The housing contains a bypass flue and at least one switching valve assembly. The bypass flue connects the flue gas inlet to the inlet of the latent heat recovery module, and / or connects the outlet of the sensible heat recovery module to the flue gas outlet. The switching valve assembly can selectively guide the flue gas through the sensible heat recovery module and / or the latent heat recovery module, or guide the flue gas through the bypass flue to bypass at least one recovery module. The control system is signal-connected to the switching valve assembly and the recovery module, and is used to control the opening and closing status of the switching valve assembly and the operation of the recovery module according to real-time operating conditions.

[0006] In some embodiments, the sensible heat recovery module includes a plate heat exchanger, the flow channel of which is a multi-pass S-shaped narrow slit flow channel. The plate heat exchanger is connected to an external cold water source through an inlet pipe, so that the external cold water source enters the plate heat exchanger through the inlet pipe and indirectly exchanges heat with the flue gas. The plate heat exchanger is connected to an external heat utilization system through an outlet pipe, so that the water that absorbs the sensible heat of the flue gas is transported to the external heat utilization system through the outlet pipe. Both the inlet pipe and the outlet pipe are equipped with regulating valves and flow sensors.

[0007] In some embodiments, the latent heat recovery module includes a packing layer, a spraying unit, and a gas-liquid separation network arranged sequentially along the flue gas flow direction, so that the flue gas can fully contact the cooling water sprayed by the spraying unit in the packing layer to recover the latent heat of the flue gas, and the gas-liquid separation network is used to separate liquid droplets carried in the flue gas after the latent heat has been recovered.

[0008] In some embodiments, the latent heat recovery module further includes a water tank and a circulation pump. The water tank is located at the bottom of the housing and is connected to the spray unit via the circulation pump and a pipeline, so that cooling water is pressurized by the circulation pump and then transported to the spray unit via the pipeline.

[0009] In some embodiments, the water tank is provided with an overflow pipe, a drain pipe, and a latent heat recovery pipe. The overflow pipe is used to control the water level in the water tank, the drain pipe is used to discharge impurities from the bottom of the water tank, and the latent heat recovery pipe is used to output hot water after recovering the latent heat of the flue gas. A water supply pipe is provided on the pipeline between the water tank and the spray unit. The water supply pipe is used to replenish fresh cold water. The drain pipe, the latent heat recovery pipe, the water supply pipe, and the pipeline between the water tank and the spray unit are all provided with regulating valves and flow sensors.

[0010] In some embodiments, the housing is provided with a flue gas inlet pipe communicating with the inlet of the sensible heat recovery module, the end of the flue gas inlet pipe away from the sensible heat recovery module being the flue gas inlet, the housing is provided with a flue gas outlet pipe communicating with the outlet of the latent heat recovery module, the end of the flue gas outlet pipe away from the latent heat recovery module being the flue gas outlet, a regulating valve being provided inside the flue gas outlet pipe, the bypass flue being located between the sensible heat recovery module and the latent heat recovery module, and the outlet of the sensible heat recovery module and the inlet of the latent heat recovery module being respectively connected to the bypass flue. The flue gas bypass module also includes a three-way pipe, the three ports of which are respectively connected to the inlet pipe, the exhaust pipe and the bypass flue. The switching valve group includes an inlet diversion valve group and an inter-section switching valve group. The inlet diversion valve group is located at the connection between the three-way pipe and the inlet pipe, and the inter-section switching valve is located at the three-way joint of the three-way pipe.

[0011] In some embodiments, a flue gas parameter sensor group is provided at the flue gas inlet, and an induced draft fan is provided at the flue gas outlet.

[0012] In some embodiments, the control system includes: The data sensing layer is used to collect flue gas parameters, environmental parameters, and operational parameters; The intelligent decision-making layer has a built-in trained algorithm model, which is used to determine the current optimal heat recovery operation mode and corresponding control commands based on the data collected by the data perception layer. The execution control layer is used to drive the switching valve group to operate and the corresponding recovery module to run according to the control instructions of the intelligent decision layer.

[0013] The embodiments of the present invention also propose a control method for a horizontal flue gas total heat recovery integrated device, which is applicable to the horizontal flue gas total heat recovery integrated device described in the above embodiments.

[0014] The control method of the horizontal flue gas total heat recovery integrated device according to the present invention includes: Real-time data collection reflecting flue gas operating conditions, environmental conditions, and system status; Based on the collected real-time data, the system intelligently decides the heat recovery operation mode to be executed, which includes at least the sensible heat recovery mode, the latent heat recovery mode, and the total heat recovery mode. Based on the determined operating mode, generate and execute the corresponding set of control instructions.

[0015] In some embodiments, When the decision is to use the sensible heat recovery mode, the flue gas flow is controlled to pass through the sensible heat recovery module and bypass the latent heat recovery module. When the decision is to use the latent heat recovery mode, the flue gas is controlled to bypass the sensible heat recovery module and flow through the latent heat recovery module. When the decision is made to use the total heat recovery mode, the control flue gas flows sequentially through the sensible heat recovery module and the latent heat recovery module.

[0016] In summary, in the embodiments of this invention, by integrating sensible heat and latent heat recovery modules and utilizing intelligent decision-making to dynamically switch between sensible heat, latent heat, and total heat operation modes, the device can deeply adapt to changes in flue gas conditions, reducing the flue gas temperature below the dew point and fully recovering latent heat of condensation. This significantly improves the overall heat recovery efficiency compared to traditional single devices (e.g., by more than 30%). Simultaneously, the unique flue gas bypass duct design achieves dedicated ducting, physically isolating non-working modules in non-total heat mode, significantly shortening the flue gas path, reducing system flow resistance, and saving induced draft fan power consumption.

[0017] The intelligent decision-making layer, based on AI algorithms such as CNN / LSTM, can comprehensively analyze real-time flue gas parameters, environmental data, and system status to proactively optimize and adaptively switch operating modes, solving the problems of coarse-grained and slow-response traditional control strategies. During latent heat recovery, the system precisely adjusts spray parameters (such as pH and flow rate) to simultaneously and efficiently remove pollutants such as SO2 (desulfurization efficiency can reach over 80%), achieving deep synergy between energy recovery and pollution control.

[0018] The horizontal integrated layout compactly integrates all functional modules, reducing the footprint and connecting pipelines. The flue gas bypass design not only saves energy but also avoids unnecessary wear, ash accumulation, and low-temperature corrosion of non-working modules. Combined with the fault warning and preventive maintenance functions of the control system, it significantly extends the equipment maintenance cycle and improves the reliability and economy of the entire life cycle operation.

[0019] The device can intelligently adapt to the start-up, shutdown, and stabilization processes of waste incineration and other technologies, as well as seasonal changes. Through multi-variable collaborative optimization algorithms, it dynamically balances multiple objectives such as heat recovery, pump and fan energy consumption, water consumption, and reagent consumption, pursuing the optimal overall system energy efficiency or the lowest total operating cost, thus achieving a leap from passive response to proactive optimization. Attached Figure Description

[0020] Figure 1This is a schematic diagram of a horizontal flue gas total heat recovery integrated device according to an embodiment of the present invention.

[0021] Figure label: 1-Housing; 11-Inlet pipe; 12-Exhaust pipe; 13-Flue gas parameter sensor group; 14-Exhaust fan; 101-Flue gas inlet; 102-Flue gas outlet; 2-Sensible heat recovery module; 21-Plate heat exchanger; 22-Inlet pipe; 23-Outlet pipe; 3-Latent heat recovery module; 31-Packing layer; 32-Spray unit; 33-Gas-liquid separation network; 34-Water tank; 35-Circulating pump; 36-Overflow pipe; 37-Sewage pipe; 38-Latent heat recovery pipe; 39-Water replenishment pipe; 4- Flue gas bypass module; 41- Bypass flue; 42- Switching valve assembly; 421- Inlet diversion valve assembly; 422- Inter-section switching valve assembly; 43- Three-way pipe. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] The horizontal flue gas total heat recovery integrated device according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0024] like Figure 1 As shown, the horizontal flue gas total heat recovery integrated device of this embodiment includes a shell 1, a sensible heat recovery module 2, a latent heat recovery module 3, and a flue gas bypass module 4.

[0025] The casing 1 has a flue gas inlet 101 and a flue gas outlet 102, and the casing 1 has a horizontal structure. A sensible heat recovery module 2 is located inside the casing 1, and recovers the sensible heat released during flue gas cooling through indirect heat exchange (such as plate or tube type). A latent heat recovery module 3 is located inside the casing 1 and downstream of the sensible heat recovery module 2, and recovers the latent heat of condensation of water vapor in the flue gas through direct gas-liquid contact (such as spraying or condensation). The latent heat recovery module 3 and the sensible heat recovery module 2 are arranged horizontally at intervals to achieve a compact structure and reduce floor space.

[0026] The flue gas bypass module 4 includes a bypass flue 41 disposed within the housing 1 and at least one switching valve assembly 42. The bypass flue 41 connects the flue gas inlet 101 to the inlet of the latent heat recovery module 3, and / or connects the outlet of the sensible heat recovery module 2 to the flue gas outlet 102, providing an alternative path that bypasses a specific module. The switching valve assembly 42 can selectively guide the flue gas through the sensible heat recovery module 2 and / or the latent heat recovery module 3, or guide the flue gas through the bypass flue 41 to bypass at least one recovery module. The switching valve assembly 42 acts as a traffic hub, capable of changing the flue gas flow direction upon command.

[0027] The device integrates a control system, which is signal-connected to the switching valve group 42 and the recovery module. This control system controls the opening and closing status of the switching valve group 42 and the operation of the recovery module based on real-time operating conditions. As the brain of the device, the control system receives signals, issues control commands, and coordinates the operation of the mechanical structure and functional units.

[0028] The device operates according to an intelligent closed-loop logic of "perception-decision-path switching-parameter adjustment": Sensing: The control system can acquire real-time operating data such as flue gas temperature, humidity, pollutant concentration, and system pressure through sensors.

[0029] Decision-making: The control system analyzes the real-time operating conditions based on preset algorithms or models (from simple threshold judgments to complex AI models) and decides on the current optimal heat recovery operation mode (e.g., recovering only sensible heat, recovering only latent heat, or recovering all heat).

[0030] Path switching: After the decision is made, the control system instructs the switching valve group 42 to act, changing the direction of flue gas flow. For example: If sensible heat recovery mode is required, the valve guides the flue gas flow through sensible heat recovery module 2, while bypassing latent heat recovery module 3 through bypass flue 41.

[0031] If latent heat recovery mode is required, the flue gas is guided to bypass the sensible heat recovery module 2 through the bypass flue 41 and directly enter the latent heat recovery module 3.

[0032] If a total heat recovery mode is required, the flue gas is guided to flow sequentially through the sensible heat and latent heat modules.

[0033] Parameter adjustment: While selecting the path, the control system synchronously adjusts the operating parameters of each recovery module, such as adjusting the cooling water flow rate of the sensible heat module, the spray volume and pH value of the latent heat module, so that the module works under optimal conditions.

[0034] The horizontal flue gas total heat recovery integrated device of this invention integrates sensible heat and latent heat modules into one unit, and has the ability to recover total heat (sensible heat and latent heat), which expands the depth and breadth of energy recovery. It can reduce the flue gas temperature to below the dew point, fully recover the condensation latent heat, significantly improve the total energy recovery rate, and reduce energy waste.

[0035] The latent heat recovery module 3 is itself a direct contact scrubber, and its operation (spray volume, pH) is regulated by the control system. While recovering latent heat, it naturally possesses the function of washing and purifying pollutants (such as SO2). Intelligent control can optimize purification efficiency, achieving synergistic effects of energy saving and emission reduction.

[0036] The control system optimizes the operation of latent heat modules (such as spray parameters) based on operating conditions and can protect equipment under adverse conditions through bypass. It optimizes heat and mass transfer processes to improve efficiency. In conditions prone to corrosion or blockage (such as low temperature and high dust), relevant modules can be bypassed to reduce equipment damage, extend lifespan, and lower maintenance costs.

[0037] The flue gas bypass module 4 and the control system constitute an intelligent actuator for reconfigurable flue gas paths, enabling physical switching of multiple operating modes. The system is no longer a fixed process, thus dynamically adapting to drastic changes in flue gas temperature, humidity and other parameters, greatly enhancing flexibility.

[0038] In non-total heating mode, flue gas does not need to flow through non-working modules, which significantly shortens the process and reduces the total system resistance. At the same time, it avoids ineffective wear, dust accumulation and corrosion of non-working modules, thus improving overall reliability and lifespan.

[0039] The horizontal integrated housing 1, with modules spaced horizontally, has a highly compact structure, which greatly reduces the floor space occupied by the device, the length of connecting pipes and air ducts, thereby reducing initial installation costs and system flow resistance, and saving fan energy consumption.

[0040] In some embodiments, such as Figure 1 As shown, the sensible heat recovery module 2 includes a plate heat exchanger 21. The flow channel of the plate heat exchanger 21 is a multi-pass S-shaped narrow slit flow channel. Compared with conventional heat exchangers, its heat transfer area per unit volume is increased by more than 25%, and the flue gas residence time can be controlled within 3-5 seconds, which significantly enhances the heat transfer efficiency.

[0041] The plate heat exchanger 21 is connected to an external cold water source through the inlet pipe 22, so that the external cold water source enters the plate heat exchanger 21 through the inlet pipe 22 to exchange heat with the flue gas indirectly. The plate heat exchanger 21 is connected to an external heat utilization system through the outlet pipe 23, so that the water that absorbs the sensible heat of the flue gas is transported to the external heat utilization system through the outlet pipe 23.

[0042] External clean cold water source (such as softened water or demineralized water) is introduced into the device through the lower water inlet pipe 22. The cold water, as the heat exchange medium, enters a specific flow channel (water-side flow channel) inside the plate heat exchanger 21.

[0043] High-temperature flue gas passes through the other side of the plate heat exchanger 21 (the flue gas side channel). The S-shaped channel extends the flow path and residence time of the flue gas and cooling water within the heat exchanger, promoting turbulence; the narrow slot channel reduces the cross-sectional area, significantly increasing the fluid velocity and turbulence. The multi-pass design causes the medium to circulate multiple times, further enhancing heat transfer. Under the combined effect of these three designs, the flue gas and cooling water undergo efficient indirect heat exchange through thin metal plates. The flue gas temperature decreases, releasing sensible heat; the cooling water absorbs heat, increasing its temperature.

[0044] The hot water, which absorbs the sensible heat of the flue gas, flows out from the outlet pipe 23 of the plate heat exchanger 21 and is transported to an external heat utilization system (e.g., heating network, process heating, water preheating, etc.), thereby realizing the recovery and utilization of heat energy. Throughout the process, the cooling medium does not come into direct contact with the flue gas, maintaining the cleanliness of the water and avoiding pollution and corrosion of the medium-side pipelines.

[0045] Both the inlet pipe 22 and the outlet pipe 23 are equipped with regulating valves and flow sensors. The flow sensors monitor the flow rates of the inlet pipe 22 and the outlet pipe 23 in real time, providing crucial operating data for the control system. The regulating valves receive instructions from the control system and dynamically adjust the flow rate of cooling water entering the plate heat exchanger 21, thereby controlling the sensible heat recovery rate and the outlet water temperature.

[0046] In this embodiment, the plate heat exchanger 21 itself has a high heat transfer area per unit volume, which helps to reduce the overall size of the device. By increasing turbulence and extending the contact time, the heat transfer coefficient between the flue gas side and the water side is significantly improved, overcoming the problem of insufficient heat transfer that may exist in traditional heat exchangers. The design allows the flue gas to complete heat exchange within 3-5 seconds, ensuring sufficient heat exchange while preventing the risk of ash accumulation due to excessive residence time or acid dew point corrosion caused by excessive cooling. The high flow rate of the flue gas helps to flush the plate surface, reduce dust deposition, and alleviate clogging problems.

[0047] The sensible heat recovery loop is clearly defined as an independent, clean closed or open loop, completely isolated from the latent heat recovery spray circulation water. This ensures the quality of the produced hot water, which can be directly used in applications with higher requirements. The interfaces for heat input (cold water source) and output (heat utilization system) are clearly defined, resulting in a higher degree of integration of the device.

[0048] In some embodiments, such as Figure 1As shown, the latent heat recovery module 3 includes a packing layer 31, a spraying unit 32, and a gas-liquid separation net 33 arranged sequentially along the flue gas flow direction, so that the flue gas can fully contact the cooling water sprayed by the spraying unit 32 in the packing layer 31 to recover the latent heat of the flue gas. The gas-liquid separation net 33 is used to separate the liquid droplets carried in the flue gas after the latent heat is recovered.

[0049] Optionally, the spiral nozzle of the spray unit 32 is a solid conical stainless steel nozzle with a spray angle of 120° and an operating pressure range of 0.2-0.3MPa, ensuring that the spray droplets uniformly cover the entire cross-section of the latent heat recovery section. The packing layer 31 uses ceramic structured packing, which has high specific surface area and low resistance characteristics, with a packing height of 900mm, providing sufficient interface for gas-liquid heat and mass transfer. The gas-liquid separation mesh 33 uses a two-stage PP material separation mesh with a mesh density of 100 mesh, which can effectively capture droplets with a particle size greater than 10μm, with a separation efficiency of ≥99.5%.

[0050] Flue gas, whether or not cooled by the sensible heat recovery module 2, enters the latent heat recovery module 3. Circulating cooling water is atomized by the spray unit 32 and sprayed from top to bottom. The flue gas flows from bottom to top and comes into countercurrent contact with the falling droplets in the packing layer 31, which prolongs the gas-liquid contact time and contact area.

[0051] When the relatively cool spray liquid comes into contact with flue gas containing a large amount of water vapor, the flue gas temperature drops below the dew point. The water vapor condenses and releases latent heat of vaporization, which is absorbed by the spray liquid, causing its temperature to rise. The spray liquid (usually water or an alkaline solution) simultaneously washes and absorbs acidic pollutants (such as SO2 and NOx) and some dust in the flue gas, achieving synergistic purification.

[0052] After heat exchange and purification, the wet flue gas passes through the gas-liquid separation network 33 before leaving the module, where tiny liquid droplets are intercepted and captured to prevent them from being carried out of the device and causing corrosion, blockage, or visible white smoke in downstream equipment.

[0053] Furthermore, such as Figure 1 As shown, the latent heat recovery module 3 also includes a water tank 34 and a circulation pump 35. The water tank 34 is located at the bottom of the housing 1. The water tank 34 is connected to the spray unit 32 through the circulation pump 35 and pipelines, so that the cooling water is pressurized by the circulation pump 35 and then transported to the spray unit 32 through the pipelines.

[0054] The spray liquid, having absorbed heat and pollutants, collects at the bottom in the water tank 34 under gravity. The circulation pump 35 pressurizes the water in the water tank 34 and delivers it back to the top spray unit 32 through pipelines, forming a closed-loop circulation.

[0055] like Figure 1 As shown, the water tank 34 is equipped with an overflow pipe 36, a drain pipe 37, and a latent heat recovery pipe 38.

[0056] The overflow pipe 36 is used to control the water level of the water tank 34 to prevent the water tank 34 from overflowing due to excessive water replenishment or other malfunctions.

[0057] The drain pipe 37 is used to discharge impurities from the bottom of the water tank 34. In order to prevent the infinite accumulation of pollutants that have been absorbed, which could lead to water acidification, equipment corrosion, or scaling, a portion of high-salinity and high-turbidity wastewater is discharged periodically or at a fixed concentration through the drain pipe 37.

[0058] The latent heat recovery pipe 38 is used to output hot water after recovering the latent heat of the flue gas. The water in the water tank 34, which has recovered the latent heat, becomes hot water and can be continuously or intermittently exported through the latent heat recovery pipe 38 and sent to an external heat utilization system (such as heating or process preheating).

[0059] A water supply pipe 39 is provided on the pipeline between the water tank 34 and the spray unit 32. Due to evaporation, sewage discharge and hot water output, the water level in the water tank 34 drops, and fresh cold water (or pH-adjusting agent) is automatically replenished through the water supply pipe 39.

[0060] The drain pipe 37, the latent heat recovery pipe 38, the water supply pipe 39, and the pipes between the water tank 34 and the spray unit 32 are all equipped with regulating valves and flow sensors.

[0061] In this embodiment, the packing layer 31 greatly expands the gas-liquid contact surface, ensuring thorough and vigorous mixing of flue gas and droplets. This brings the water vapor condensation and pollutant absorption processes close to their theoretical limits, significantly improving latent heat recovery and purification efficiency. The gas-liquid separation mesh 33 effectively removes droplets, ensuring dry and clean exhaust gas and preventing secondary pollution and downstream equipment problems.

[0062] A self-sustaining spray liquid circulation system was established, enabling the latent heat recovery process to continue continuously. Water tank 34 serves as a heat storage and buffer unit, allowing the spray liquid temperature to gradually increase, facilitating a stable output of high-quality hot water. Placing water tank 34 at the bottom of the shell 1 further embodies the integrated and compact design concept.

[0063] By intelligently replenishing water and discharging wastewater, the water level and contaminant concentration in water tank 34 are dynamically controlled, fundamentally preventing equipment corrosion and scaling blockage caused by water quality deterioration. Adjusting the valve on the latent heat recovery pipe 38 controls the hot water output and temperature to match external heat demand. The flow sensor provides key data such as water replenishment rate, wastewater discharge rate, and hot water production rate, forming the essential data foundation for the control system to achieve multi-variable collaborative optimization (such as balancing heat recovery, water consumption, and chemical consumption). The overflow pipe 36 serves as a safety redundancy, and the wastewater pipe 37 is located at the bottom for easy slag removal; these designs enhance the long-term stability and reliability of the device.

[0064] In some embodiments, such as Figure 1As shown, the housing 1 is provided with a flue gas inlet pipe 11 that is connected to the inlet of the sensible heat recovery module 2. The end of the flue gas inlet pipe 11 away from the sensible heat recovery module 2 is a flue gas inlet 101. The housing 1 is provided with a flue gas outlet pipe 12 that is connected to the outlet of the latent heat recovery module 3. The end of the flue gas outlet pipe 12 away from the latent heat recovery module 3 is a flue gas outlet 102. A regulating valve is provided in the flue gas outlet pipe 12. The bypass flue 41 is located between the sensible heat recovery module 2 and the latent heat recovery module 3. The outlet of the sensible heat recovery module 2 and the inlet of the latent heat recovery module 3 are respectively connected to the bypass flue 41.

[0065] The flue gas bypass module 4 also includes a three-way pipe 43, the three ports of which are connected to the inlet pipe 11, the exhaust pipe 12 and the bypass flue 41 respectively. The switching valve group 42 includes an inlet diversion valve group 421 and an inter-section switching valve group 422. The inlet diversion valve group 421 is located at the connection between the three-way pipe 43 and the inlet pipe 11, and the inter-section switching valve is located at the three-way joint of the three-way pipe 43.

[0066] During the sensible heat recovery process, the inlet diversion valve assembly 421 activates, closing the passage to the three-way pipe 43 and directing all the flue gas into the flue pipe 11, thereby entering the sensible heat recovery module 2. The inter-stage switching valve assembly 422 activates, opening the passage to the flue gas outlet 102 and directing the flue gas from the sensible heat recovery module 2 to the bypass flue 41.

[0067] Final path: Flue gas inlet 101 → flue gas inlet pipe 11 → sensible heat recovery module 2 → bypass flue 41 → tee pipe 43 → exhaust pipe 12 → flue gas outlet 102. Latent heat recovery module 3 is completely physically isolated.

[0068] During the latent heat recovery process, the inlet diversion valve assembly 421 activates, closing the passage to the sensible heat recovery module 2 and directing all the flue gas to the three-way pipe 43. The inter-stage switching valve assembly 422 activates, opening the passage to the bypass flue 41 and directing the flue gas through the bypass flue 41 to the latent heat recovery module 3.

[0069] Final path: Flue gas inlet 101 → flue gas inlet pipe 11 → tee pipe 43 → bypass flue 41 → latent heat recovery module 3 → exhaust pipe 12 → flue gas outlet 102. Sensible heat recovery module 2 is completely physically isolated.

[0070] During the total heat recovery process, the inlet diversion valve assembly 421 activates, closing the passage to the three-way pipe 43 and directing all the flue gas into the inlet pipe 11, which then enters the sensible heat recovery module 2. The inter-stage switching valve assembly 422 activates, closing the passage to the bypass flue 41 and directing the flue gas from the sensible heat module to the latent heat recovery module 3.

[0071] Final path: Flue gas inlet 101 → flue gas inlet pipe 11 → sensible heat recovery module 2 → latent heat recovery module 3 → flue gas exhaust pipe 12 → flue gas outlet 102. The bypass flue 41 is completely isolated, and the flue gas flows through the two modules sequentially.

[0072] In some embodiments, such as Figure 1 As shown, a flue gas parameter sensor group 13 is installed at the flue gas inlet 101. The sensor probes are directly exposed to the raw flue gas entering the device, continuously or frequently performing physical or chemical analysis on the flue gas sample. The detected physical quantities or chemical concentrations are converted into standard electrical signals (such as 4-20mA current signals, 0-10V voltage signals, or digital signals). The electrical signals are transmitted to the control system in real time via cable or industrial bus, serving as the core input data for the control system's decision-making.

[0073] The flue gas parameter sensor group 13 can be integrated from multiple independent sensors. For example, a temperature sensor measures the flue gas temperature to determine the sensible heat content, decide whether to activate the sensible heat recovery mode, and prevent low-temperature corrosion; a humidity sensor measures the absolute or relative humidity of the flue gas to assess the latent heat content, calculate the dew point temperature, and decide whether to activate the latent heat recovery mode; an SO2 concentration sensor measures the sulfur dioxide concentration to assess the pollution load and intelligently adjust the pH value of the spray liquid in the latent heat recovery module 3 (such as initiating chemical dosing) and the discharge frequency accordingly to achieve synergistic desulfurization; and a flow / pressure sensor monitors the flue gas flow rate or inlet static pressure to calculate the total heat load, assess changes in system resistance, and coordinate with the induced draft fan 14 for control.

[0074] An induced draft fan 14 is installed at the flue gas outlet 102. The induced draft fan 14 is used to maintain the negative pressure operation of the entire device and the subsequent flue system to overcome flow resistance.

[0075] The motor drives the impeller to rotate at high speed. The rotating impeller does work on the flue gas, increasing its kinetic and pressure energy, creating positive pressure at the fan outlet, and the required negative pressure (suction) at the fan inlet and the entire upstream system.

[0076] The suction force is used to overcome all the resistance of the device body in sequence (including the sensible heat module flow channel, the latent heat module packing layer 31, the gas-liquid separation network 33, valves, pipes, elbows, etc.), the different resistance generated by the flue gas bypass module 4 in different modes, and the resistance of the subsequent flue and chimney.

[0077] By adjusting the motor speed via a frequency converter or by adjusting the inlet guide vanes, the air volume and pressure head of the induced draft fan 14 can be changed, thereby adapting to changes in boiler load and the device's own resistance (such as when switching between different modes), ensuring stable flue gas flow.

[0078] In some embodiments, the control system includes a data sensing layer, an intelligent decision-making layer, and an execution control layer.

[0079] The data sensing layer is used to collect flue gas parameters, environmental parameters, and operational parameters. Flue gas parameters reflect the essential attributes of the treated object (temperature, humidity, pollutant concentration). Environmental parameters reflect external boundary conditions (ambient temperature, humidity, season). Operational parameters reflect the real-time operating status of the device itself (flow rate in each pipeline, valve opening, water level in the tank, pump frequency).

[0080] The data perception layer transforms the continuous state of the physical world into a discrete data stream that can be processed by the digital world, providing factual basis for upper-level decision-making. The comprehensiveness and real-time nature of its data collection directly determine the accuracy and timeliness of the decisions.

[0081] The intelligent decision-making layer has a built-in trained algorithm model used to determine the optimal heat recovery operation mode and corresponding control commands based on the data collected by the data perception layer. First, the raw data uploaded by the perception layer is cleaned (denoise removal, outlier removal), standardized, and fused to form a high-quality dataset suitable for analysis. The processed real-time data, along with possible historical time-series data, is then input into the built-in trained algorithm model.

[0082] This model encapsulates complex mapping relationships. Input: Current and historical operating condition data (X). Output: The optimal control strategy (Y) for the current state.

[0083] The model calculates and outputs two key decisions: the optimal heat recovery operation mode (whether to activate sensible heat mode, latent heat mode, or total heat mode) and the corresponding control command set (i.e., target set values ​​for each actuator (valve, pump, etc.) in that mode, such as opening degree, frequency, and flow rate).

[0084] By using a data-driven approach, the system can automatically learn and summarize the optimal control rules from massive amounts of data, enabling it to handle complex system optimization problems involving multiple variables, nonlinearity, and strong coupling.

[0085] The execution control layer drives the switching valve group 42 and the corresponding recovery module to operate according to the control commands from the intelligent decision-making layer. It translates the digital commands output by the intelligent decision-making layer into actual physical actions. It receives commands from the decision-making layer, parses them, and distributes them to the corresponding actuator drivers.

[0086] Send switching or regulating signals to the switching valve group 42 (inlet diversion valve, inter-stage switching valve) to change the flue gas flow direction; at the same time, send control signals to the regulating valves and circulating pumps 35 of each recovery module to adjust their operating parameters (such as cooling water flow rate and spray volume).

[0087] The accuracy and speed of the execution of decisions, which accurately and reliably realize the decision-making intent and complete the closed loop from digital instructions to physical actions, directly affect whether the system can operate stably in the optimal state set by the decision-making level.

[0088] In this embodiment, artificial intelligence algorithms are deeply embedded in the industrial control process, transforming the device from a passive heat exchanger into an intelligent agent capable of sensing the environment, making decisions, and proactively optimizing. This three-layer architecture clearly defines functional boundaries, giving the system a high degree of modularity and scalability. For example, the algorithm model can be continuously trained and iterated with new data, becoming stronger without changing the hardware or basic control logic.

[0089] The following describes a control method for a horizontal flue gas total heat recovery integrated device according to an embodiment of the present invention. This control method is applicable to the horizontal flue gas total heat recovery integrated device described in the above embodiment.

[0090] The control method of the horizontal flue gas total heat recovery integrated device according to the present invention includes: Real-time data collection reflecting flue gas operating conditions, environmental conditions, and system status; Based on the collected real-time data, the system intelligently decides the heat recovery operation mode to be executed, which includes at least sensible heat recovery mode, latent heat recovery mode and total heat recovery mode. Based on the determined operating mode, generate and execute the corresponding set of control instructions.

[0091] The control method of this invention establishes control logic based on the analysis of real-time data across all dimensions (operating conditions, environment, system status). It can not only determine high or low temperatures but also combine humidity, pollutant concentration, ambient temperature, and even user-side heat demand to make more refined mode selections. The decision objective can be to maximize total heat recovery or to maximize net benefit (heat gain - fan and pump power consumption), thereby maximizing overall energy efficiency at the end of the energy conversion chain.

[0092] Whether it's the start-up and shutdown of a waste incinerator, load fluctuations, or seasonal changes in the environment, this method, through a continuous data acquisition-decision cycle, can always find a feasible and optimal operating mode under the current conditions. The intelligent decision-making process can consider system inertia, achieving a smooth transition between different modes and avoiding equipment stress or process fluctuations caused by sudden parameter changes. When a sensor fails or the performance of some modules degrades, the decision-making method based on multi-source data fusion can rely on other data to infer and select a degraded but safe operating mode, improving system reliability.

[0093] By integrating heat recovery objectives (mode selection) and environmental protection objectives (pollutant concentration as input data) into a unified decision-making framework, the generated control instruction set is the result of collaborative optimization. For example, when SO2 concentration increases, the decision-making system may not only maintain or switch to latent heat mode, but also simultaneously optimize the pH adjustment instructions for the spray liquid and the sewage discharge strategy in the instruction set; when pursuing heat recovery, the impact of the increased flow resistance on the power consumption of the induced draft fan 14 will also be considered.

[0094] Whether it's simple expert rule bases and fuzzy control, or advanced machine learning algorithms (such as CNN / LSTM) and reinforcement learning algorithms, all can be embedded into the intelligent decision-making process, protecting a broad range of technologies from traditional automation to artificial intelligence control. This methodological framework encourages and relies on data accumulation. As the amount of operational data increases, the decision model can be continuously trained and optimized, achieving sustained performance improvements.

[0095] When the decision is made to use the sensible heat recovery mode, the flue gas flow is controlled to pass through the sensible heat recovery module 2 and bypass the latent heat recovery module 3. Only the cooling water circuit operates, and the spray circulating water circuit is completely stopped.

[0096] When the decision is made to use latent heat recovery mode, the flue gas bypasses the sensible heat recovery module 2 and flows through the latent heat recovery module 3. Only the spray circulating water circuit operates, while the cooling water circuit stops.

[0097] When the decision is made to use the total heat recovery mode, the flue gas flows sequentially through the sensible heat recovery module 2 and the latent heat recovery module 3. The cooling water circuit and the spray circulating water circuit operate simultaneously. The flue gas first recovers sensible heat through the cooling water, and then the cooled flue gas enters the spray section where the latent heat is recovered by the circulating water. The control system will coordinate the control parameters of the two circuits to maximize the total heat recovery.

[0098] The following describes the operating conditions of a horizontal flue gas total heat recovery integrated device, taking the entire process of start-up, stabilization, and shutdown of a waste incineration line as an example.

[0099] During the initial startup phase (sensible heat recovery mode), the flue gas temperature is 180℃, the humidity is <10%, and the SO2 concentration is low.

[0100] The control system detects the high temperature and low humidity characteristics and activates the sensible heat recovery mode. It shuts down the latent heat recovery module 3, activates the sensible heat recovery module 2, and automatically adjusts the regulating valves of the cooling water inlet pipe 22 and outlet pipe 23 according to the target hot water temperature (e.g., 60℃). Flue gas bypasses the latent heat recovery module 3 through the flue gas bypass module 4, protecting it from low-temperature corrosion.

[0101] Flue gas enters the sensible heat recovery module 2 from the flue gas inlet 101, and indirectly exchanges heat with the cooling water along the S-shaped flow channel. After releasing sensible heat, it is discharged after passing through the bypass flue 41. The cooling water absorbs heat and is then discharged to the hot water utilization system through the outlet pipe 23. Fresh cooling water is replenished through the inlet pipe 22.

[0102] During stable operation (total heat recovery mode), the flue gas temperature is 140℃, the humidity is >20%, and the SO2 concentration reaches the design value.

[0103] The control system switches to total heat recovery mode and simultaneously activates sensible heat recovery module 2 and latent heat recovery module 3.

[0104] The flue gas is first cooled to 70-80℃ by cooling water in the sensible heat recovery module 2 to complete sensible heat exchange, and then enters the latent heat recovery module 3 where it is further cooled to 30-40℃ by spray circulating water to release latent heat. Finally, it is discharged after gas-liquid separation. The heat absorbed by the cooling water and the spray circulating water is discharged and reused through the outlet pipe 23 and the latent heat recovery pipe 38, respectively.

[0105] The control system coordinates and optimizes the two water circuits: for example, while ensuring that the flue gas temperature meets the standard, it appropriately increases the cooling water outlet temperature to improve the sensible heat quality, and at the same time optimizes the spray water volume to achieve the dual goals of latent heat recovery and desulfurization efficiency. Based on real-time monitoring of pH and turbidity, the control system automatically performs chemical dosing and wastewater discharge to maintain the health of the water circuits.

[0106] During the shutdown transition period (latent heat recovery mode → system purging), the flue gas temperature and load gradually decrease.

[0107] The control system invokes the shutdown model, first switching to latent heat recovery mode and shutting down sensible heat recovery module 2. Hot water production continues using waste heat from the flue gas, and pollutant purification continues. When the flue gas temperature is too low, the control system stops latent heat recovery module 3, but keeps induced draft fan 14 running for a period of time to purge the spray section and flue, evaporating residual moisture from the surfaces and preventing equipment corrosion after shutdown. During this process, drain pipe 37 performs a forced septic tank discharge to remove high-concentration wastewater.

[0108] Flue gas enters the latent heat recovery module 3 from the flue gas inlet 101 via the bypass flue 41, and comes into full contact with the circulating water sprayed by the spray unit 32 in the packing layer 31, releasing latent heat (including the latent heat of water vapor condensation). After heat exchange, the flue gas is discharged after being demisted by the gas-liquid separation net 33, and the circulating water falls back to the water tank 34 and is discharged through the latent heat recovery pipe 38.

[0109] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0110] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0111] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0112] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0113] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0114] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A horizontal flue gas total heat recovery integrated device, characterized in that, include: The housing is provided with a flue gas inlet and a flue gas outlet; A sensible heat recovery module is disposed inside the housing and is used for indirect heat exchange with flue gas to recover sensible heat. A latent heat recovery module is disposed inside the housing and located downstream of the sensible heat recovery module. It is used to directly contact the flue gas for heat exchange to recover latent heat. The latent heat recovery module and the sensible heat recovery module are arranged at intervals along the horizontal direction. A flue gas bypass module, comprising a bypass flue and at least one switching valve assembly disposed within the housing, wherein the bypass flue connects the flue gas inlet to the inlet of the latent heat recovery module, and / or connects the outlet of the sensible heat recovery module to the flue gas outlet, and the switching valve assembly may selectively guide the flue gas to flow through the sensible heat recovery module and / or the latent heat recovery module, or guide the flue gas to bypass at least one recovery module through the bypass flue; The control system is signal-connected to the switching valve group and the recovery module, and is used to control the opening and closing status of the switching valve group and the operation of the recovery module according to the real-time operating conditions.

2. The horizontal flue gas total heat recovery integrated device according to claim 1, characterized in that, The sensible heat recovery module includes a plate heat exchanger. The flow channel of the plate heat exchanger is a multi-pass S-shaped narrow slit flow channel. The plate heat exchanger is connected to an external cold water source through an inlet pipe, so that the external cold water source enters the plate heat exchanger through the inlet pipe and indirectly exchanges heat with the flue gas. The plate heat exchanger is connected to an external heat utilization system through an outlet pipe, so that the water that absorbs the sensible heat of the flue gas is transported to the external heat utilization system through the outlet pipe. Both the inlet pipe and the outlet pipe are equipped with regulating valves and flow sensors.

3. The horizontal flue gas total heat recovery integrated device according to claim 1, characterized in that, The latent heat recovery module includes a packing layer, a spraying unit, and a gas-liquid separation net arranged sequentially along the flue gas flow direction, so that the flue gas can fully contact the cooling water sprayed by the spraying unit in the packing layer to recover the latent heat of the flue gas. The gas-liquid separation net is used to separate the liquid droplets carried in the flue gas after the latent heat has been recovered.

4. The horizontal flue gas total heat recovery integrated device according to claim 3, characterized in that, The latent heat recovery module also includes a water tank and a circulation pump. The water tank is located at the bottom of the shell and is connected to the spray unit via the circulation pump and pipeline, so that the cooling water is pressurized by the circulation pump and then transported to the spray unit via the pipeline.

5. The horizontal flue gas total heat recovery integrated device according to claim 4, characterized in that, The water tank is equipped with an overflow pipe, a drain pipe, and a latent heat recovery pipe. The overflow pipe is used to control the water level in the water tank, the drain pipe is used to discharge impurities from the bottom of the water tank, and the latent heat recovery pipe is used to output hot water after recovering the latent heat of the flue gas. A water supply pipe is provided on the pipeline between the water tank and the spray unit to replenish fresh cold water. The drain pipe, the latent heat recovery pipe, the water supply pipe, and the pipeline between the water tank and the spray unit are all equipped with regulating valves and flow sensors.

6. The horizontal flue gas total heat recovery integrated device according to claim 1, characterized in that, The housing is provided with a flue gas inlet pipe that communicates with the inlet of the sensible heat recovery module. The end of the flue gas inlet pipe away from the sensible heat recovery module is the flue gas inlet. The housing is provided with a flue gas outlet pipe that communicates with the outlet of the latent heat recovery module. The end of the flue gas outlet pipe away from the latent heat recovery module is the flue gas outlet. A regulating valve is provided inside the flue gas outlet pipe. The bypass flue is located between the sensible heat recovery module and the latent heat recovery module. The outlet of the sensible heat recovery module and the inlet of the latent heat recovery module are respectively connected to the bypass flue. The flue gas bypass module also includes a three-way pipe, the three ports of which are respectively connected to the inlet pipe, the exhaust pipe and the bypass flue. The switching valve group includes an inlet diversion valve group and an inter-section switching valve group. The inlet diversion valve group is located at the connection between the three-way pipe and the inlet pipe, and the inter-section switching valve is located at the three-way joint of the three-way pipe.

7. The horizontal flue gas total heat recovery integrated device according to claim 1, characterized in that, A flue gas parameter sensor group is installed at the flue gas inlet, and an induced draft fan is installed at the flue gas outlet.

8. The horizontal flue gas total heat recovery integrated device according to claim 1, characterized in that, The control system includes: The data sensing layer is used to collect flue gas parameters, environmental parameters, and operational parameters; The intelligent decision-making layer has a built-in trained algorithm model, which is used to determine the current optimal heat recovery operation mode and corresponding control commands based on the data collected by the data perception layer. The execution control layer is used to drive the switching valve group to operate and the corresponding recovery module to run according to the control instructions of the intelligent decision layer.

9. A control method for a horizontal flue gas total heat recovery integrated device, characterized in that, The control method is applicable to the horizontal flue gas total heat recovery integrated device according to any one of claims 1-8, and the control method includes: Real-time data collection reflecting flue gas operating conditions, environmental conditions, and system status; Based on the collected real-time data, the system intelligently decides the heat recovery operation mode to be executed, which includes at least the sensible heat recovery mode, the latent heat recovery mode, and the total heat recovery mode. Based on the determined operating mode, generate and execute the corresponding set of control instructions.

10. The control method for the horizontal flue gas total heat recovery integrated device according to claim 9, characterized in that, When the decision is to use the sensible heat recovery mode, the flue gas flow is controlled to pass through the sensible heat recovery module and bypass the latent heat recovery module. When the decision is to use the latent heat recovery mode, the flue gas is controlled to bypass the sensible heat recovery module and flow through the latent heat recovery module. When the decision is made to use the total heat recovery mode, the control flue gas flows sequentially through the sensible heat recovery module and the latent heat recovery module.

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