Energy saving device and method for thermal power plant with recovered water vapor structure

Abstract

This invention relates to the field of steam recovery technology, and discloses an energy-saving device and method for thermal power plants with a steam recovery structure. The device includes a flue gas diversion module, a steam pretreatment module, and a condensation recovery module. The flue gas diversion module, steam pretreatment module, and condensation recovery module are sequentially connected in series along the direction of the mixed airflow of flue gas and steam. The inlet of the flue gas diversion module is circulatedly connected to the exhaust port of the condensation recovery module and to the flue gas duct of the thermal power plant, respectively, for collecting flue gas and steam. The cooling medium end of the condensation recovery module is connected to the supply and return pipes of the circulating cooling water in the thermal power plant. This invention achieves effective collection and circulation treatment of flue gas and steam by circulating the flue gas diversion module with the flue gas duct and the exhaust port of the condensation recovery module. Simultaneously, it utilizes the existing circulating cooling water in the thermal power plant as the condensation medium, eliminating the need for an additional cooling system and reducing equipment investment costs.

Description

Technical Field

[0001] This invention relates to the field of steam recovery technology, specifically to an energy-saving device and method for thermal power plants with a steam recovery structure. Background Technology

[0002] During the production process of thermal power plants, the flue gas emitted from their boiler flues and the exhaust gas emitted from their cooling towers contain a large amount of water vapor. Taking the cooling tower as an example, the plume of white mist emitted from it has an extremely high water vapor content. This part of the high-temperature and high-humidity exhaust gas is directly discharged into the atmosphere, which not only causes a huge waste of water resources, but also carries a large amount of latent heat of vaporization, resulting in energy loss.

[0003] Existing flue gas treatment technologies for thermal power plants, such as flue gas whitening or waste heat recovery devices, typically only treat flue gas individually and fail to simultaneously address the comprehensive recovery of flue gas and water vapor from cooling towers. Furthermore, existing devices generally suffer from the following shortcomings when treating high-humidity flue gas: First, the water vapor in the flue gas is not pretreated before condensation, making it difficult for tiny water droplets to condense efficiently, resulting in low condensation recovery efficiency. Second, the flue gas often contains acidic gases, which easily form acid mist during condensation, causing severe corrosion to equipment and affecting the service life and operational stability of the device. Summary of the Invention

[0004] In order to overcome the defects of the existing technology, the purpose of this invention is to provide an energy-saving device and method for thermal power plants with a steam recovery structure, so as to solve the technical problems of low condensation recovery efficiency of existing flue gas treatment technology in thermal power plants, and the fact that the flue gas often contains acidic gases, which easily form acid mist during the condensation process, causing serious corrosion to the equipment.

[0005] This invention is achieved through the following technical solution: In a first aspect, the present invention provides an energy-saving device for a thermal power plant with a steam recovery structure, including a flue gas diversion module, a steam pretreatment module, and a condensation recovery module; The flue gas diversion module, the water vapor pretreatment module, and the condensation recovery module are connected in series along the direction of the mixed airflow of flue gas and water vapor. The inlet of the flue gas diversion module is connected to the exhaust port of the condensation recovery module and to the flue of the thermal power plant, respectively, for collecting flue gas and water vapor. The cooling medium end of the condensation recovery module is used to connect to the power plant's circulating cooling water supply and return pipes.

[0006] Preferably, the flue gas diversion module includes a diversion fan, an electric three-way diversion valve, and an insulated diversion pipe; The air inlet of the induced draft fan is connected to the exhaust port of the condensation recovery module and to the flue of the thermal power plant. The outlet of the induced draft fan is connected to the inlet of an electric three-way diverter valve via a pipeline. The outlet end of the electric three-way diverter valve is connected to the inlet end of the insulated drain pipe via a flange. The outlet end of the insulated drainage pipe is connected to the inlet end of the steam pretreatment module; The outer wall of the heat-insulating drainage pipe is covered with an aluminum silicate insulation cotton layer.

[0007] Preferably, the water vapor pretreatment module includes a shell; the shell has a vertical cylindrical closed structure, the interior of the shell has a cavity structure, wherein the upper part of the cavity is provided with an acid mist adsorption layer, the middle part of the cavity is provided with a dust removal filter, and the lower part of the cavity is provided with a water vapor pre-condensation unit; The lower part of the housing is provided with a mixed gas inlet for horizontal connection with the output end of the flue gas diversion module via a flange, and the top of the housing is provided with a mixed gas outlet for connection with the inlet end of the condensation recovery module via a flange. The bottom of the housing is provided with a drain port, and the drain port is equipped with a drain valve.

[0008] Furthermore, the shell is made of carbon steel and the inner lining of the shell is an anti-corrosion layer; the dust filter is installed in the middle of the inner cavity of the shell via a slot-type guide rail; the acid mist adsorption layer is a fixed bed structure, filling the upper part of the inner cavity of the shell and limited by upper and lower perforated plates.

[0009] Furthermore, the side of the casing is provided with a maintenance manhole and a packing port; the packing port is located on the casing corresponding to the position of the acid mist adsorption layer.

[0010] Furthermore, the water vapor pre-condensation unit is an ultrasonic condenser, which includes an ultrasonic generator and a transducer array; The ultrasonic generator is fixedly installed on the outside of the housing; The transducer array includes multiple ultrasonic transducers, each of which is installed on the lower wall of the cavity of the housing. The transducer array is connected to an ultrasonic generator via cables. The ultrasonic generator outputs high-frequency electrical signals to the transducer array, causing the ultrasonic transducers to generate ultrasonic vibrations, forming a sound field in the inner cavity of the shell, which in turn causes water vapor molecules to vibrate at high frequency and collide and condense with each other.

[0011] Preferably, the condensation recovery module includes a horizontal housing and a steel support frame; The horizontal housing is horizontally mounted on a steel support. One side of the horizontal housing has an air inlet, which is connected to the output of the water vapor pretreatment module. The other side of the horizontal housing has an exhaust port, which is used to connect to an external exhaust pipe. The bottom of the horizontal housing is provided with a condensate drain outlet for the discharge of condensate. The horizontal shell is equipped with a multi-stage condensing heat exchanger. The cooling water inlet of the multi-stage condensing heat exchanger is located on the lower side of the horizontal shell and is used to connect to the circulating cooling water supply pipe of the thermal power plant. The cooling water outlet of the multi-stage condensing heat exchanger is located on the upper side of the horizontal shell and is connected to the circulating cooling water return pipe of the thermal power plant.

[0012] Furthermore, the multi-stage condensing heat exchanger includes a first-stage heat exchanger and a second-stage heat exchanger; The first-stage heat exchanger and the second-stage heat exchanger are connected in series. The cooling water inlet of the first-stage heat exchanger and the second-stage heat exchanger is located on the lower side of the horizontal shell and is used to connect with the circulating cooling water supply pipe of the thermal power plant. The cooling water outlet of the first-stage heat exchanger and the second-stage heat exchanger is located on the upper side of the horizontal shell and is connected with the circulating cooling water return pipe of the thermal power plant.

[0013] Furthermore, the condensation recovery module also includes a condensate collection tank, which is installed inside a steel support and located directly below the horizontal shell. The top of the condensate collection tank is provided with a water inlet, which is connected to the condensate drain outlet. The bottom side of the condensate collection tank is provided with a water outlet, and the top is provided with a level gauge.

[0014] Secondly, the present invention also provides a method for using an energy-saving device for a thermal power plant with a steam recovery structure, based on the above-described energy-saving device for a thermal power plant with a steam recovery structure, comprising the following process: The flue gas diversion module is activated, and its inlet end is connected to the exhaust port of the power plant flue and the condensation recovery module respectively. The flue gas in the power plant flue and the exhaust gas discharged from the condensation recovery module are collected. At the same time, water vapor from the cooling tower exhaust port is drawn in. After being mixed by the flue gas diversion module, it is sent to the water vapor pretreatment module. After the mixed airflow enters the water vapor pretreatment module, it first undergoes ultrasonic condensation, which causes the tiny water droplets in the airflow to collide and condense into larger droplets under the action of the sound field. Then, after rising and passing through the dust removal, the acidic aerosols in the airflow are removed, thus completing the water vapor pretreatment. The pretreated mixed airflow is sent into the condensation recovery module, and the cooling medium end of the condensation recovery module is connected to the power plant's circulating cooling water supply and return pipes. The circulating cooling water is used to provide cooling for the multi-stage condensation heat exchanger in the condensation recovery module. The mixed airflow exchanges heat with the multi-stage condensation heat exchanger, so that the water vapor in the airflow is cooled and condensed into liquid water. The condensed liquid water is stored in the condensation recovery module for industrial water reuse; the dried exhaust gas after condensation is discharged through the exhaust port of the condensation recovery module, and part of the exhaust gas is recycled to the air inlet of the flue gas diversion module to participate in the collection again, realizing the dual recovery of water resources and heat.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: This invention provides an energy-saving device for thermal power plants with a steam recovery structure. Through the circular connection of the flue gas diversion module with the power plant's flue and the exhaust port of the condensation recovery module, effective collection and circulation of flue gas and steam are achieved. Simultaneously, the existing circulating cooling water in the power plant is used as the condensation medium, eliminating the need for an additional cooling system and reducing equipment investment costs. The orderly coordination of the three modules lays the foundation for improving condensation recovery efficiency and solving acid mist corrosion problems. It initially realizes the comprehensive treatment of flue gas and steam, providing structural support for the dual recovery of water resources and heat, and specifically alleviating the problem of low condensation recovery efficiency in existing technologies.

[0016] Furthermore, the flue gas diversion module includes a diversion fan, an electric three-way diverter valve, and an insulated diversion pipe covered with aluminum silicate insulation cotton. The diversion fan can efficiently collect flue gas from the thermal power plant and tail gas from the condensation recovery module. The electric three-way diverter valve can flexibly adjust the mixed gas ratio, solving the problem of incomplete treatment of single-source waste gas and realizing comprehensive waste gas treatment and resource utilization. The insulated diversion pipe can effectively reduce heat loss of the mixed gas during transportation, avoiding the decrease in recovery efficiency caused by premature condensation of water vapor. At the same time, the aluminum silicate insulation cotton layer has good thermal insulation effect, reducing energy loss and further improving the energy efficiency of the device, indirectly ensuring the efficiency of the subsequent condensation recovery stage.

[0017] Furthermore, the vertical cylindrical enclosed shell design facilitates the sequential passage of the mixed gas through each pretreatment stage from top to bottom. The layered arrangement of the water vapor pre-condensation unit, dust filter, and acid mist adsorption layer allows the mixed gas to first complete water droplet condensation, then dust removal, and finally acid mist adsorption, achieving pretreatment in a step-by-step manner. This effectively avoids the impact of dust and acid mist on subsequent condensation equipment. The drain port and drain valve at the bottom of the shell can promptly discharge waste liquid and impurities generated during the pretreatment process, preventing accumulation and clogging of the equipment, ensuring the stable operation of the pretreatment module, providing a clean gas source for improving the efficiency of subsequent condensation recovery, and initially alleviating the corrosion problem of acid mist on the equipment.

[0018] Furthermore, the carbon steel shell, coupled with an inner anti-corrosion lining, directly resists corrosion from acidic substances in the gas mixture, extending the shell's service life. The dust filter uses a slot-type guide rail installation, facilitating later disassembly, cleaning, and replacement, reducing maintenance difficulty and costs. The acid mist adsorption layer adopts a fixed bed structure and is limited by a perforated plate, ensuring uniform and stable filling of the adsorption layer, improving the adsorption effect on acidic aerosols, effectively removing acidic substances from the gas mixture, preventing acidic substances from entering the condensation recovery module and causing corrosion to the equipment, while ensuring the stability and efficiency of the dust removal and adsorption processes, improving the pretreatment effect, and providing a guarantee for improving condensation recovery efficiency.

[0019] Furthermore, a maintenance manhole and a packing filling port are added. The maintenance manhole facilitates the inspection, maintenance, and replacement of components such as the dust filter and acid mist adsorption layer inside the shell, reducing the difficulty and cost of equipment maintenance and minimizing equipment downtime. The packing filling port corresponds to the position of the acid mist adsorption layer, facilitating the replenishment and replacement of the acid mist adsorption packing, ensuring that the acid mist adsorption layer always maintains good adsorption performance, continuously and effectively removing acidic substances from the mixed gas, avoiding acid mist corrosion of the equipment, ensuring the long-term stable operation of the pretreatment module and the entire device, and indirectly ensuring the stability of the condensation recovery efficiency.

[0020] Furthermore, the water vapor pre-condensation unit is an ultrasonic condenser. An ultrasonic generator and transducer array create a high-frequency sound field within the shell cavity, causing water vapor molecules and tiny water droplets to vibrate at high frequencies, collide, and condense. This significantly increases the droplet size, solving the problem of low condensation recovery efficiency caused by the difficulty in condensing tiny water droplets in existing technologies. Ultrasonic condensation requires no chemical reagents, making it environmentally friendly. Simultaneously, the condensation effect is stable, providing larger droplets for subsequent condensation recovery stages, greatly improving the condensation efficiency of the condensation recovery module, thereby increasing water resource recycling rates. It also reduces the corrosion of equipment by acidic substances carried by tiny water droplets, extending the equipment's service life.

[0021] Furthermore, the horizontal shell is mounted on a steel support, ensuring structural stability and facilitating sufficient residence of the mixed gas within the shell for thorough heat exchange with the multi-stage condensing heat exchanger. The multi-stage condensing heat exchanger increases the heat exchange area, and by using the existing circulating cooling water of the thermal power plant as the cooling medium, no additional cooling equipment is required, reducing investment costs. At the same time, the circulating cooling water efficiently removes heat, allowing the water vapor in the mixed gas to be fully cooled and condensed, significantly improving condensation recovery efficiency. The rational layout of the air inlet, exhaust outlet, and condensate drain outlet ensures the orderly intake of the mixed gas, exhaust gas emission, and condensate discharge, guaranteeing a smooth and efficient condensation recovery process. Additionally, a portion of the exhaust gas can be recycled to the flue gas diversion module, achieving waste gas recycling and improving resource utilization.

[0022] Furthermore, the multi-stage condensing heat exchanger is further refined into a first-stage heat exchanger and a second-stage heat exchanger arranged in series. The series structure allows the mixed gas to pass through two stages of heat exchange sequentially, gradually cooling it and improving heat exchange efficiency. This ensures that the water vapor in the mixed gas is fully condensed, effectively solving the problem of low condensation recovery efficiency in existing technologies. The two-stage heat exchangers share the same cooling water supply and return pipelines, eliminating the need for additional cooling pipelines, simplifying the equipment structure, and reducing investment and maintenance costs. At the same time, the recycling of cooling water improves the energy efficiency of the device, achieving effective heat recovery and taking into account both water resource and heat recovery effects.

[0023] Furthermore, a condensate collection tank is added, located directly below the horizontal shell, facilitating centralized collection of condensate, preventing condensate loss, and improving water resource recycling rate. The inlet and outlet of the condensate collection tank are connected to ensure that all condensate flows into the collection tank, while the outlet allows the collected condensate to be drawn out for industrial water reuse, realizing the resource utilization of water resources. The level gauge can monitor the condensate level in the collection tank in real time, allowing staff to understand the amount of condensate recovered and rationally arrange reuse, while preventing condensate overflow, ensuring stable equipment operation, improving the water resource recycling process, and enhancing the practicality and energy efficiency of the device.

[0024] This invention also provides a method for using an energy-saving device for thermal power plants with a steam recovery structure. By activating the flue gas diversion module, flue gas, steam, and exhaust gas are collected and mixed, solving the problem of incomplete treatment of single waste gas. In the steam pretreatment stage, the step-by-step operation of ultrasonic condensation, dust removal, and acid mist adsorption increases the droplet size to improve subsequent condensation efficiency, removes dust and acidic substances, avoids equipment corrosion, extends equipment life, and reduces maintenance costs. In the condensation recovery stage, the circulating cooling water of the thermal power plant is used to achieve full condensation of steam. Combined with condensate collection and exhaust gas circulation, dual recovery of water resources and heat is achieved. This comprehensively solves the technical problems of low condensation recovery efficiency and easy corrosion of equipment by acid mist in existing thermal power plant flue gas treatment technologies. At the same time, it improves resource utilization and energy efficiency, ensuring that the device can operate stably and efficiently and achieve actual energy-saving recovery effects. Attached Figure Description

[0025] Figure 1 This is a first schematic diagram of the overall structure of the energy-saving device for a thermal power plant in an embodiment of the present invention; Figure 2 This is a second schematic diagram of the overall structure of the energy-saving device for a thermal power plant in an embodiment of the present invention; Figure 3 This is a third schematic diagram of the overall structure of the energy-saving device for a thermal power plant in an embodiment of the present invention; Figure 4 This is a fourth schematic diagram of the overall structure of the energy-saving device for a thermal power plant in an embodiment of the present invention; In the diagram: 1. Flue gas diversion module; 2. Steam pretreatment module; 3. Condensation recovery module; 4. Diversion fan; 5. Electric three-way diverter valve; 6. Insulated diversion pipe; 7. Shell; 8. Steam pre-condensation unit; 9. Dust filter; 10. Acid mist adsorption layer; 11. Mixed gas inlet; 12. Mixed gas outlet; 13. Drain; 14. Manhole; 15. Packing port; 16. Ultrasonic generator; 17. Transducer array; 18. Horizontal shell; 19. Steel support; 20. Air inlet; 21. Exhaust outlet; 22. Condensate drain outlet; 23. Multi-stage condensing heat exchanger; 24. First-stage heat exchanger; 25. Second-stage heat exchanger; 26. Condensate collection tank; 27. Water inlet; 28. Water outlet; 29. ​​Level gauge. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] The purpose of this invention is to provide an energy-saving device and method for thermal power plants with a steam recovery structure, in order to solve the technical problems of low condensation recovery efficiency of existing flue gas treatment technologies for thermal power plants, and the fact that flue gas often contains acidic gases, which easily form acid mist during the condensation process, causing serious corrosion to the equipment.

[0029] The present invention will now be described in further detail with reference to the accompanying drawings: Example 1 See Figures 1-4In one embodiment of the present invention, an energy-saving device for a thermal power plant with a steam recovery structure is provided. The device includes a flue gas diversion module 1, a steam pretreatment module 2, and a condensation recovery module 3, arranged in series along the direction of the mixed flow of flue gas and steam. The modules work together to achieve comprehensive treatment of flue gas and steam, and dual recovery of water resources and heat. The specific structure is as follows: The flue gas diversion module 1 is used to collect flue gas from the flue of the thermal power plant and water vapor from the exhaust port of the cooling tower. Its inlet end is connected to the flue of the thermal power plant and the exhaust port of the cooling tower respectively, and its outlet end is connected to the water vapor pretreatment module 2. The flue gas diversion module 1 includes a diversion fan 4, an electric three-way diversion valve 5, and an insulated diversion pipe 6. The inlet of the diversion fan 4 is connected to the side wall opening of the flue of the thermal power plant via a pipeline, and is also connected to the side wall opening of the exhaust port of the cooling tower via a pipeline, which can efficiently extract two types of gases. The inlet of the electric three-way diversion valve 5 is connected to the outlet of the diversion fan 4 via a pipeline, which can adjust the ratio of flue gas and water vapor according to a preset program or real-time detection data to optimize the subsequent treatment effect. The inlet of the insulated diversion pipe 6 is connected to the outlet of the electric three-way diversion valve 5 via a flange, and the outlet is connected to the inlet of the water vapor pretreatment module 2. The outer wall of the insulated diversion pipe 6 is covered with an aluminum silicate insulation cotton layer, which can effectively reduce the heat loss of the mixed gas during the transportation process and ensure the activity of the water vapor.

[0030] The water vapor pretreatment module 2 is used to condense, remove dust and acid from the mixed gas to prevent dust and acidic substances from affecting the operation of subsequent equipment. It includes a vertical cylindrical closed shell 7, a water vapor pre-condensation unit 8, a dust removal filter 9 and an acid mist adsorption layer 10. The shell 7 is made of carbon steel and lined with an anti-corrosion layer (such as glass flakes or polyurea coating) to resist corrosion by acidic substances and extend the service life of the equipment. The lower side of the shell 7 is provided with a mixed gas inlet 11, which is horizontally connected to the outlet of the insulated drainage pipe 6 through a flange for receiving mixed gas. The top center of the shell 7 is provided with a mixed gas outlet 12, which is vertically connected to the condensation recovery module 3 through a flange for discharging the pretreated gas. The lowest point of the bottom of the shell 7 is provided with a drain port 13, equipped with a drain valve, which can promptly discharge the waste liquid and impurities generated during the pretreatment process to prevent blockage. The middle side of the shell 7 is provided with a maintenance manhole 14 for easy maintenance of internal components. The shell 7 is provided with an openable packing filling port 15 at the position corresponding to the acid mist adsorption layer 10 for easy replenishment and replacement of the adsorption packing.

[0031] The water vapor pre-condensation unit 8 is located in the lower part of the inner cavity of the shell 7 and is an ultrasonic condenser, including an ultrasonic generator 16 and a transducer array 17. The ultrasonic generator 16 is fixedly installed on the outside of the pretreatment shell 7. The transducer array 17 is composed of multiple ultrasonic transducers, each of which is installed on the wall of the shell 7. The transducer array 17 is connected to the ultrasonic generator 16 through a cable. The ultrasonic generator 16 outputs a high-frequency electrical signal of 20-40kHz to the transducer array 17, causing the ultrasonic transducers to generate ultrasonic vibrations, forming a sound field in the inner cavity of the shell 7, which promotes the high-frequency vibration of water vapor molecules and their collision and condensation, increasing the droplet size and improving the efficiency of subsequent condensation and recovery.

[0032] The dust filter 9 is installed in the middle of the inner cavity of the housing 7 via a slot-type guide rail, making it easy to remove for cleaning or replacement. It is used to trap dust particles in the mixed gas and prevent them from clogging downstream heat exchange equipment. The acid mist adsorption layer 10 is a fixed bed structure, filled with acid-resistant adsorption packing material (such as silica gel, activated alumina or modified molecular sieve). It is filled in the upper part of the inner cavity of the housing 7 and limited by the upper and lower perforated plates. It can effectively adsorb acidic aerosols such as SO3 in the mixed gas, significantly reduce the acidity of the gas, and provide a guarantee for the long-term stable operation of the subsequent condensation recovery module 3.

[0033] The condensation recovery module 3 is used to condense and recover water vapor in the pretreated mixed gas. Its cooling medium channel is connected to the power plant's circulating cooling water supply and return pipes, eliminating the need for additional cooling equipment and reducing investment costs. The condensation recovery module 3 includes a horizontal shell 18, a steel support 19, a multi-stage condensation heat exchanger 23, and a condensate collection tank 26. The horizontal shell 18 is horizontally installed on the steel support 19, ensuring structural stability. One end of the horizontal shell 18 has an air inlet 20 on its lower side, which is connected to the top outlet of the water vapor pretreatment module 2 via a vertical drop pipe and a 90° elbow, for receiving the pretreated mixed gas. The other end of the horizontal shell 18 has an exhaust port 21 on its upper side, which is connected to an external exhaust gas pipe for discharging the dried exhaust gas. The bottom of the horizontal shell 18 has a condensate drain port 22 for discharging the liquid water formed by condensation.

[0034] A multi-stage condensing heat exchanger 23 is installed inside a horizontal shell 18, including at least a first-stage heat exchanger 24 and a second-stage heat exchanger 25 arranged in series. The series arrangement allows the mixed gas to pass through two stages of heat exchange sequentially, gradually cooling it and improving the condensation recovery efficiency. The cooling water inlet of the first-stage heat exchanger 24 is located on the lower side of the horizontal shell 18 and is connected to the circulating cooling water supply pipe of the thermal power plant. Its cooling water outlet is located on the upper side of the horizontal shell 18 and is connected to the circulating cooling water return pipe of the thermal power plant. The cooling water inlet of the second-stage heat exchanger 25 is located on the lower side of the horizontal shell 18 and is connected to the circulating cooling water supply pipe of the thermal power plant. Its cooling water outlet is located on the upper side of the horizontal shell 18 and is connected to the circulating cooling water return pipe of the thermal power plant, realizing the efficient utilization of circulating cooling water.

[0035] The condensate collection tank 26 is located directly below the horizontal shell 18. It has an inlet 27 at the top, which is connected to the condensate drain 22 at the bottom of the horizontal shell 18 for centralized collection of condensate. The bottom side of the condensate collection tank 26 has an outlet 28, which facilitates the collection of condensate for industrial water reuse. The top of the condensate collection tank 26 has a level gauge 29 for real-time monitoring of the level, which helps staff control the drainage and prevents condensate from overflowing.

[0036] In summary, this embodiment provides an energy-saving device for thermal power plants with a steam recovery structure. Through the circular connection of the flue gas diversion module with the flue gas duct and the exhaust port of the condensate recovery module, it achieves effective collection and circulation of flue gas and steam. At the same time, it utilizes the existing circulating cooling water of the thermal power plant as the condensation medium, eliminating the need for an additional cooling system and reducing equipment investment costs. The orderly cooperation of the three modules lays the foundation for improving condensate recovery efficiency and solving acid mist corrosion problems. It initially realizes the comprehensive treatment of flue gas and steam, provides structural support for the dual recovery of water resources and heat, and specifically alleviates the problem of low condensate recovery efficiency in existing technologies.

[0037] Example 2 This embodiment also provides a method for using an energy-saving device for thermal power plants with a steam recovery structure. Based on the device described in Embodiment 1, the specific steps are as follows: First, the diversion fan 4 in the flue gas diversion module 1 is started. The diversion fan 4 draws flue gas from the flue of the thermal power plant and water vapor from the exhaust port of the cooling tower through its air inlet. After the two types of gases are drawn in, they enter the electric three-way diversion valve 5. The electric three-way diversion valve 5 adjusts the ratio of flue gas to water vapor according to the preset program or real-time detection data. The mixed gas is sent to the water vapor pretreatment module 2 through the heat-insulated diversion pipe 6. The aluminum silicate insulation cotton layer on the outer wall of the heat-insulated diversion pipe 6 can effectively reduce the heat loss of the mixed gas during the transportation process and ensure the activity of the water vapor.

[0038] The mixed gas enters the housing 7 of the steam pretreatment module 2 through the mixed gas inlet 11. It first passes through the steam pre-condensation unit 8 at the bottom of the housing 7, where the ultrasonic generator 16 is activated. The ultrasonic generator 16 outputs a high-frequency electrical signal of 20-40kHz to the transducer array 17, causing each ultrasonic transducer in the transducer array 17 to generate ultrasonic vibration, forming a sound field in the housing 7. This causes the tiny water droplets in the mixed gas to vibrate at high frequency and collide with each other under the action of the sound field, significantly increasing the droplet size. Subsequently, the mixed gas flows upward and passes through the dust filter 9 in the middle of the housing 7. The dust filter 9 traps dust particles in the mixed gas to prevent dust from clogging downstream heat exchange equipment. Then, the mixed gas continues to rise and passes through the acid mist adsorption layer 10 at the top of the housing 7. The acid-resistant adsorption packing in the acid mist adsorption layer 10 adsorbs acidic aerosols such as SO3 in the mixed gas, reducing the acidity of the gas and completing the pretreatment of the mixed gas. Waste liquid and impurities generated during the pretreatment process are discharged through the drain port 13 and the drain valve at the bottom of the housing 7.

[0039] After pretreatment, the mixed gas is discharged through the mixed gas outlet 12 at the top of the shell 7, and enters the horizontal shell 18 of the condensation recovery module 3 through the vertical descending pipe and 90° bend and the air inlet 20. At the same time, the multi-stage condensation heat exchanger 23 of the condensation recovery module 3 is connected to the power plant's circulating cooling water supply and return pipes. The circulating cooling water enters the cooling water channels of the first-stage heat exchanger 24 and the second-stage heat exchanger 25, and fully exchanges heat with the mixed gas in the horizontal shell 18. The water vapor in the mixed gas is gradually cooled and condenses into liquid water.

[0040] The condensed liquid water flows out through the condensate drain outlet 22 at the bottom of the horizontal shell 18 and into the condensate collection tank 26 through the inlet 27. The staff monitors the liquid level in the condensate collection tank 26 in real time through the level gauge 29. When the liquid level reaches the preset value, the collected condensate is led out through the outlet 28 for reuse as industrial water. The dried exhaust gas after condensation is discharged into the atmosphere through the exhaust port 21 at the other end of the horizontal shell 18, realizing the dual recovery of water resources and heat.

[0041] In addition, during long-term operation of the device, the dust filter screen 9, acid mist adsorption layer 10 and other components can be inspected, maintained and replaced through the inspection manhole 14 on the side of the shell 7; when the adsorption performance of the acid mist adsorption layer 10 decreases, the adsorption packing can be replenished or replaced through the packing filling port 15 to ensure that the device always operates stably and efficiently.

[0042] In summary, the method for using an energy-saving device for thermal power plants with a steam recovery structure provided in this embodiment solves the problem of incomplete treatment of single waste gases by activating the flue gas diversion module to collect and mix flue gas, steam, and tail gas. In the steam pretreatment stage, the step-by-step operation of ultrasonic condensation, dust removal, and acid mist adsorption increases the droplet size to improve subsequent condensation efficiency, removes dust and acidic substances, avoids equipment corrosion, extends equipment life, and reduces maintenance costs. The condensation recovery stage utilizes the circulating cooling water of the thermal power plant to achieve full condensation of steam. Combined with condensate collection and tail gas circulation, it achieves dual recovery of water resources and heat, comprehensively solving the technical problems of low condensation recovery efficiency and easy corrosion of equipment by acid mist in existing thermal power plant flue gas treatment technologies. At the same time, it improves resource utilization and energy efficiency, ensuring that the device can operate stably and efficiently and achieve actual energy-saving recovery effects.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An energy-saving device for thermal power plants with a steam recovery structure, characterized in that, It includes a flue gas diversion module (1), a steam pretreatment module (2), and a condensation recovery module (3); The flue gas diversion module (1), the water vapor pretreatment module (2), and the condensation recovery module (3) are connected in series along the direction of the mixed airflow of flue gas and water vapor; The inlet of the flue gas diversion module (1) is connected to the exhaust port of the condensation recovery module (3) and to the flue of the thermal power plant, respectively, for collecting flue gas and water vapor. The cooling medium end of the condensation recovery module (3) is used to connect to the power plant's circulating cooling water supply pipe and return pipe.

2. The energy-saving device for a thermal power plant with a steam recovery structure according to claim 1, characterized in that, The flue gas diversion module (1) includes a diversion fan (4), an electric three-way diversion valve (5), and an insulated diversion pipe (6). The air inlet of the induced draft fan (4) is connected to the exhaust port of the condensation recovery module (3) and to the flue of the thermal power plant. The outlet of the induced draft fan (4) is connected to the inlet of the electric three-way diverter valve (5) via a pipeline; The outlet end of the electric three-way diverter valve (5) is connected to the inlet end of the insulated drain pipe (6) via a flange; The outlet end of the heat-insulating drainage pipe (6) is connected to the inlet end of the steam pretreatment module (2); The outer wall of the heat-insulating drainage pipe (6) is covered with an aluminum silicate insulation cotton layer.

3. The energy-saving device for a thermal power plant with a steam recovery structure according to claim 1, characterized in that, The water vapor pretreatment module (2) includes a shell (7); the shell (7) has a vertical cylindrical closed structure, and the interior of the shell (7) has a cavity structure, wherein the upper part of the cavity is provided with an acid mist adsorption layer (10), the middle part of the cavity is provided with a dust removal filter (9), and the lower part of the cavity is provided with a water vapor pre-condensation unit (8). The lower part of the housing (7) is provided with a mixed gas inlet (11) for horizontal connection with the output end of the flue gas diversion module (1) via a flange. The top of the housing (7) is provided with a mixed gas outlet (12) for connection with the inlet end of the condensation recovery module (3) via a flange. The bottom of the housing (7) is provided with a drain port (13), and the drain port (13) is provided with a drain valve.

4. The energy-saving device for a thermal power plant with a steam recovery structure according to claim 3, characterized in that, The shell (7) is made of carbon steel and the inner lining of the shell (7) is a corrosion-resistant layer; the dust filter (9) is installed in the middle of the inner cavity of the shell (7) through a slot-type guide rail; the acid mist adsorption layer (10) is a fixed bed structure, which fills the upper part of the inner cavity of the shell (7) and is limited by the upper and lower perforated plates.

5. The energy-saving device for a thermal power plant with a steam recovery structure according to claim 4, characterized in that, The side of the housing (7) is provided with a maintenance manhole (14) and a packing port (15); wherein the packing port (15) is set on the housing (7) in a position corresponding to the acid mist adsorption layer (10).

6. The energy-saving device for a thermal power plant with a steam recovery structure according to claim 4, characterized in that, The water vapor pre-condensation unit (8) is an ultrasonic condenser, including an ultrasonic generator (16) and a transducer array (17). The ultrasonic generator (16) is fixedly installed on the outside of the housing (7); The transducer array (17) includes multiple ultrasonic transducers, each of which is installed on the lower wall of the cavity of the housing (7). The transducer array (17) is connected to the ultrasonic generator (16) via a cable. The ultrasonic generator (16) outputs a high-frequency electrical signal to the transducer array (17), causing the ultrasonic transducer to generate ultrasonic vibrations, forming a sound field in the inner cavity of the shell (7), which causes water vapor molecules to vibrate at high frequency and collide and condense with each other.

7. The energy-saving device for a thermal power plant with a steam recovery structure according to claim 1, characterized in that, The condensation recovery module (3) includes a horizontal shell (18) and a steel support (19). The horizontal housing (18) is horizontally mounted on the steel bracket (19). One side of the horizontal housing (18) is provided with an air inlet (20), which is connected to the output end of the water vapor pretreatment module (2). The other side of the horizontal housing (18) is provided with an exhaust port (21) for connecting to an external exhaust pipe. The bottom of the horizontal housing (18) is provided with a condensate drain outlet (22) for the discharge of condensate; The horizontal shell (18) is equipped with a multi-stage condensing heat exchanger (23). The cooling water inlet of the multi-stage condensing heat exchanger (23) is located on the lower side of the horizontal shell (18) and is used to connect with the circulating cooling water supply pipe of the thermal power plant. The cooling water outlet of the multi-stage condensing heat exchanger (23) is located on the upper side of the horizontal shell (18) and is connected with the circulating cooling water return pipe of the thermal power plant.

8. The energy-saving device for a thermal power plant with a steam recovery structure according to claim 7, characterized in that, The multi-stage condensing heat exchanger (23) includes a first-stage heat exchanger (24) and a second-stage heat exchanger (25); The first-stage heat exchanger (24) and the second-stage heat exchanger (25) are connected in series. The cooling water inlet of the first-stage heat exchanger (24) and the second-stage heat exchanger (25) is located on the lower side of the horizontal shell (18) and is used to connect with the circulating cooling water supply pipe of the thermal power plant. The cooling water outlet of the first-stage heat exchanger (24) and the second-stage heat exchanger (25) is located on the upper side of the horizontal shell (18) and is connected with the circulating cooling water return pipe of the thermal power plant.

9. An energy-saving device for a thermal power plant with a steam recovery structure according to claim 7, characterized in that, The condensation recovery module (3) also includes a condensate collection tank (26), which is installed inside a steel bracket (19) and located directly below the horizontal shell (18). The top of the condensate collection tank (26) is provided with a water inlet (27), which is connected to the condensate drain outlet (22). The bottom side of the condensate collection tank (26) is provided with a water outlet (28), and the top is provided with a level gauge (29).

10. A method of using an energy-saving device for a thermal power plant with a steam recovery structure, characterized in that, An energy-saving device for a thermal power plant with a steam recovery structure according to any one of claims 1-9 includes the following process: Start the flue gas diversion module (1), and connect the exhaust ports of the power plant flue and the condensation recovery module (3) through its air inlet end. The flue gas in the power plant flue and the tail gas discharged from the condensation recovery module (3) are collected. At the same time, water vapor from the cooling tower exhaust port is drawn in. After being mixed by the flue gas diversion module (1), it is sent to the water vapor pretreatment module (2). After the mixed airflow enters the water vapor pretreatment module (2), it first undergoes ultrasonic condensation, which causes the tiny water droplets in the airflow to collide and condense into larger droplets under the action of the sound field. Then, after rising and passing through the dust removal, the acidic aerosol in the airflow is removed, thus completing the water vapor pretreatment. The pretreated mixed airflow is sent into the condensation recovery module (3), so that the cooling medium end of the condensation recovery module (3) is connected to the power plant's circulating cooling water supply pipe and return pipe. The circulating cooling water is used to provide cooling for the multi-stage condensation heat exchanger in the condensation recovery module (3). The mixed airflow exchanges heat with the multi-stage condensation heat exchanger, so that the water vapor in the airflow is cooled and condensed into liquid water. The condensed liquid water is stored in the condensation recovery module (3) for industrial water reuse; the dried exhaust gas after condensation is discharged through the exhaust port of the condensation recovery module (3), and part of the exhaust gas is recycled to the air inlet of the flue gas diversion module (1) to participate in the collection again, so as to realize the dual recovery of water resources and heat.

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