Flue gas water recovery system for removing pollutants by wet method

Abstract

The invention provides a flue gas water recovery system for removing pollutants by a wet method, saturated wet flue gas enters a coupling flue gas dehumidification unit, and the coupling flue gas dehumidification unit is provided with a dehumidification module unit; the dehumidification module unit with saturated adsorption enters the negative pressure regeneration steam recovery unit under the control of the control system, and the negative pressure regeneration steam recovery unit releases water adsorbed in the dehumidification module unit in the form of water vapor by using the heat of the self-adaptive closed thermal coupling energy recovery unit; regenerated water vapor enters a negative pressure steam condensation unit and is cooled into condensed water; condensed water generated by the negative pressure steam condensation unit enters the condensed water purification unit to be purified. The invention provides a process flow with low energy consumption for flue gas water recovery of wet-process pollutant removal.

Description

Technical Field

[0001] The present invention relates to the technical field of pollutant recovery, and in particular to a flue gas water recovery system for wet removal of pollutants. Background Art

[0002] In recent years, the policies promulgated by the state have put forward a series of requirements for industrial water conservation and pollution reduction, and pointed out that industrial water use can be reduced through cascade water use, recycling water, and promoting water-saving processes, and clarified the main direction of industrial water conservation.

[0003] Existing flue gas water recovery systems for wet-process pollutant removal (SOx, dust, particulate matter, NH3, etc.) produce flue gas at the scrubbing equipment outlet at saturated humidity and high water vapor content. A boiler flue gas desulfurization system processing 700,000 standard cubic meters of flue gas per hour consumes 30 tons of water per hour, and the flue gas at the tower outlet is saturated and wet at 50-60°C, resulting in a waste of water resources. The system's water consumption is closely related to the flue gas volume, flue gas temperature, and flue gas water content. Generally speaking, the greater the flue gas volume, the more water evaporates to cool the flue gas, and the greater the amount of water carried away by the clean flue gas. Existing water-saving methods focus on reducing flue gas temperature by installing an inlet flue gas heat exchanger, thereby reducing water consumption. However, there is still no effective method for recovering saturated water from the outlet flue gas. Existing systems also reduce the water content of the flue gas by lowering its temperature. However, this requires a cooling source, typically obtained through circulating cooling water, and does not effectively reduce water consumption.

[0004] Patent document CN207153449U discloses a device for removing composite pollutants from flue gas from coal-fired boilers. The device is installed between the outlet of a desulfurization absorption tower and the inlet of a wet electrostatic precipitator. The device includes an alkaline solution spray system, a flue gas condensation system, an electrostatic precipitator system, and a wastewater recovery and reuse system, which are sequentially connected by a flue. The alkaline solution spray system, flue gas condensation system, and electrostatic precipitator system adsorb and remove a mixture of water droplets and pollutants. The wastewater containing the removed mixed pollutants is recovered through the wastewater recovery and reuse system and used as make-up water for wet desulfurization in the desulfurization absorption tower. However, this patent document still suffers from the drawback of being unable to effectively recover saturated water from the outlet flue gas.

[0005] The present invention belongs to the field of flue gas water recovery for wet pollutant removal. The amount of water consumed by the system is the amount of water output to the outside minus the amount of water brought in by the original flue gas. Summary of the Invention

[0006] In view of the defects in the prior art, the purpose of the present invention is to provide a flue gas water recovery system for wet removal of pollutants.

[0007] According to the present invention, a flue gas water recovery system for wet pollutant removal includes: a coupled flue gas dehumidification unit, a negative pressure regeneration steam recovery unit, a negative pressure steam condensation unit, a condensate purification unit, an adaptive closed thermal coupling energy recovery unit, and a control system;

[0008] The saturated wet flue gas enters the coupled flue gas dehumidification unit, which is provided with a dehumidification module unit for adsorbing water vapor in the saturated wet flue gas and discharging dry flue gas;

[0009] The dehumidification module unit that is saturated with adsorption enters the negative pressure regeneration steam recovery unit under the control of the control system. The negative pressure regeneration steam recovery unit uses the heat of the adaptive closed thermal coupling energy recovery unit to release the water adsorbed in the dehumidification module unit in the form of water vapor, thereby regenerating the water adsorbed in the dehumidification module unit;

[0010] The regenerated water vapor enters the negative pressure steam condensation unit, is cooled into condensed water, and generates a vacuum degree at the same time. The negative pressure steam condensation unit is connected to the negative pressure regeneration steam recovery unit and can transfer the generated vacuum degree to the negative pressure regeneration steam recovery unit;

[0011] After regeneration, the dehumidification module returns to the initial adsorption state and returns to the coupled flue gas dehumidification unit through the control system, and contacts the saturated wet flue gas again to adsorb moisture in the saturated wet flue gas, thereby achieving cyclic adsorption;

[0012] The condensed water generated by the negative pressure steam condensation unit enters the condensed water purification unit for purification.

[0013] Preferably, the dehumidification module unit is a coupled flue gas dehumidification unit, which adopts a mixture of one or more of activated carbon, silica gel, lithium chloride, calcium chloride and zinc chloride.

[0014] Preferably, the control system includes: a temperature and humidity control system;

[0015] The dehumidification module unit that is saturated with adsorption enters the negative pressure regeneration steam recovery unit under the control of the temperature and humidity control system.

[0016] Preferably, the input parameters of the temperature and humidity control system are the humidity of the flue gas, the temperature of the flue gas, the temperature of the dehumidification module unit, the humidity of the dehumidification module unit, and the pressure of the dehumidification module unit;

[0017] The control parameter of the temperature and humidity control system is the contact area efficiency between the working medium and the flue gas of the dehumidification module unit;

[0018] The target control parameters of the temperature and humidity control system are the saturated humidity of the dehumidification module unit and the humidity of the flue gas after dehumidification.

[0019] Preferably, the negative pressure regeneration steam recovery unit comprises: a flue gas heat collector, a heat medium transmission pipeline, a heat receiver, and a heat supply device;

[0020] The flue gas heat extractor is used to absorb the heat of the incoming high-temperature flue gas and transfer the absorbed heat to the heat receiver through the heat medium transmission pipeline;

[0021] The heat receiver receives the heat transferred by the flue gas heat exchanger, and supplies the received heat to the dehumidification module unit through the heat supply device.

[0022] Preferably, the flue gas water recovery system further comprises: a heat control system;

[0023] The negative pressure regeneration steam recovery unit supplies heat to the dehumidification module unit that is saturated with adsorption through the heat control system;

[0024] The negative pressure regeneration steam recovery unit releases the water adsorbed in the dehumidification module unit in the form of water vapor under the heat rising condition of the heat control system, thereby being regenerated.

[0025] Preferably, the input parameters of the heat control system are the humidity of the dehumidification module unit, the pressure of the dehumidification module unit, and the pressure of the negative pressure regeneration steam recovery unit;

[0026] The control parameters of the heat control system are the temperature of the negative pressure regeneration steam recovery unit and the heat input of the negative pressure regeneration steam recovery unit;

[0027] The target control parameter of the heat control system is the humidity of the dehumidification module unit.

[0028] Preferably, the negative pressure steam condensation unit comprises: an air cooler;

[0029] The water vapor released by the dehumidification module unit enters the negative pressure steam condensation unit, and the negative pressure steam condensation unit cools and condenses the water vapor through the air cooler regulated by variable frequency to form a vacuum degree;

[0030] The dehumidification module unit reduces the temperature under the action of the air cooler.

[0031] Preferably, the flue gas water recovery system further comprises: a condensation control system;

[0032] After the water vapor released by the dehumidification module unit enters the negative pressure steam condensation unit, the water vapor is condensed under the control of the condensation control system;

[0033] The input parameters of the condensation control system are the pressure of water vapor, the temperature of water vapor, and the humidity of the dehumidification module unit;

[0034] The control parameter of the condensation control system is the frequency of the air cooler.

[0035] Preferably, the condensate purification unit comprises: a membrane separation purification device;

[0036] The membrane separation purification device purifies the condensate water by one or more combined processes of ultrafiltration, nanofiltration, and reverse osmosis;

[0037] The flue gas water recovery system also includes: purification control system;

[0038] The input parameters of the purification control system are the conductivity of the influent, the concentration of characteristic pollutants, and the flow rate of characteristic pollutants;

[0039] The control parameters of the purification control system are the regulating valve and the frequency of the variable frequency pump of the purification device;

[0040] The target parameters of the purification control system are the conductivity of the outlet water and the concentration of characteristic pollutants.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. The present invention first adsorbs moisture in wet flue gas through a coupled flue gas dehumidification unit, and then regenerates the moisture adsorbed by the coupled flue gas dehumidification unit through a negative pressure regeneration steam recovery unit. The regenerated moisture is condensed and purified to reach the quality of desalted water, which can be used as boiler water supplement or circulating cooling water supplement, or can be deeply treated to achieve ultrapure water. The regenerated coupled flue gas dehumidification unit can adsorb again, perform cyclic adsorption and release, thereby reducing the amount of water carried away by the flue gas, thereby greatly reducing the waste of water resources.

[0043] 2. The negative pressure steam condensation unit in the present invention is connected to the negative pressure regeneration steam recovery unit. The regenerated water vapor enters the negative pressure steam condensation unit, is cooled into condensed water, and a vacuum degree is generated at the same time. Because it is connected to the negative pressure regeneration steam recovery unit, the vacuum degree is transmitted, thereby improving the regeneration efficiency of the negative pressure regeneration steam recovery unit and reducing the regeneration temperature.

[0044] 3. The present invention collects and utilizes the heat in the high-temperature flue gas through the negative pressure regeneration steam recovery unit and the adaptive closed thermal coupling energy recovery unit to provide the heat required by the negative pressure regeneration steam recovery unit, thereby utilizing the heat in the high-temperature flue gas and achieving the purpose of energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0046] Figure 1 Schematic diagram of the structure of a flue gas water recovery system for wet pollutant removal in one embodiment.

[0047] The figure shows:

[0048] First flue gas duct 1 Second air cooler 11

[0049] Flue gas heat exchanger 2 Condensate purification unit 12

[0050] Flue gas inlet 3 Temperature and humidity control system 13

[0051] Purification equipment 4 Heat control system 14

[0052] Flue gas purification flue 5 Condensation control system 15

[0053] Heat receiver 6 Purification control system 16

[0054] Dehumidification module unit 7 discharge port 17

[0055] Second flue gas duct 8 Purified recycled water 18

[0056] Emission chimney 9 Discharge concentrated water 19

[0057] First air cooler 10 Heat medium transmission pipeline 20 DETAILED DESCRIPTION

[0058] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0059] Example 1

[0060] like Figure 1As shown, this embodiment provides a flue gas water recovery system for wet removal of pollutants, comprising: a coupled flue gas dehumidification unit, a negative pressure regenerative steam recovery unit, a negative pressure steam condensation unit, a condensate purification unit, an adaptive closed thermal coupling energy recovery unit and a control system; saturated wet flue gas enters the coupled flue gas dehumidification unit, and the coupled flue gas dehumidification unit is provided with a dehumidification module unit 7 for adsorbing water vapor in the saturated wet flue gas and discharging dry flue gas; the adsorbed saturated dehumidification module unit 7 enters the negative pressure regenerative steam recovery unit under the control of the control system, and the negative pressure regenerative steam recovery unit utilizes the heat of the adaptive closed thermal coupling energy recovery unit to dehumidify the saturated wet flue gas. The water adsorbed in the wet module unit 7 is released in the form of water vapor, and the water adsorbed in the dehumidification module unit 7 is regenerated; the regenerated water vapor enters the negative pressure steam condensation unit, is cooled into condensed water, and a vacuum degree is generated at the same time. The negative pressure steam condensation unit is connected to the negative pressure regeneration steam recovery unit, and can transfer the generated vacuum degree to the negative pressure regeneration steam recovery unit; after regeneration, the dehumidification module unit 7 returns to the initial adsorption state, returns to the coupled flue gas dehumidification unit through the control system, and contacts with the saturated wet flue gas again, adsorbs the moisture in the saturated wet flue gas, and realizes cyclic adsorption; the condensed water generated by the negative pressure steam condensation unit enters the condensate purification unit for purification.

[0061] Adaptive closed thermal coupling energy recovery unit consists of Figure 1 The system consists of a first flue gas duct 1, a flue gas heat extractor 2, a purified flue gas duct 5, and a heat receiver 6. This unit uses a control system to rationally supply heat to the saturated dehumidification module 7, regenerating it and releasing steam. The control system input parameters are the humidity and pressure of the dehumidification module 7, and the pressure of the negative pressure regeneration steam recovery unit. The control parameters are the temperature and heat input of the negative pressure regeneration steam recovery unit. The target control parameter is the humidity of the dehumidification module 7.

[0062] The dehumidification module unit 7 continuously realizes the cycle of "contact with wet flue gas - reach adsorption saturation - contact with regenerator - contact with wet flue gas again" through a continuous disc rotating structure or a belt conveying structure or other similar continuous conveying structure.

[0063] The negative pressure regenerative steam recovery unit includes: a flue gas heat exchanger 2, a heat medium transmission pipeline, a heat receiver 6, and a heat supply device. The flue gas heat exchanger 2 absorbs heat from the incoming high-temperature flue gas and transfers the absorbed heat to the heat receiver 6 via the heat medium transmission pipeline. The heat receiver 6 receives the heat transferred by the flue gas heat exchanger 2 and supplies the received heat to the dehumidification module 7 via the heat supply device. The flue gas water recovery system also includes: a heat control system 14. The negative pressure regenerative steam recovery unit supplies heat to the dehumidification module 7, which has reached adsorption saturation, through the heat control system 14. Under the heat-raising conditions of the heat control system 14, the negative pressure regenerative steam recovery unit releases the adsorbed water in the dehumidification module 7 as water vapor, thereby regenerating the water. The input parameters of the heat control system 14 are the humidity of the dehumidification module, the pressure of the dehumidification module, and the pressure of the negative pressure regenerative steam recovery unit. The control parameters of the heat control system 14 are the temperature of the negative pressure regenerative steam recovery unit and the heat input of the negative pressure regenerative steam recovery unit. The target control parameter of the heat control system 14 is the humidity of the dehumidification module. It is implemented through heat medium water circulation regulation, closed-loop water pressure stabilization control, water quality monitoring and treatment, DCS / PLC integrated control and other means.

[0064] Dehumidification module 7 is a coupled flue gas dehumidification unit, utilizing a mixture of one or more of activated carbon, silica gel, lithium chloride, calcium chloride, and zinc chloride. The control system includes a temperature and humidity control system 13. The adsorption-saturated dehumidification module 7 enters the negative pressure regeneration steam recovery unit under the control of the temperature and humidity control system 13. The input parameters of the temperature and humidity control system 13 are flue gas humidity, flue gas temperature, dehumidification module unit temperature, dehumidification module unit humidity, and dehumidification module unit pressure. The control parameter of the temperature and humidity control system 13 is the contact area efficiency between the working fluid and flue gas in the dehumidification module unit. The target control parameters of the temperature and humidity control system 13 are the saturated humidity after the dehumidification module unit and the humidity of the flue gas after dehumidification.

[0065] The specific composition of the temperature and humidity control system includes humidity detection, temperature detection, and a PID control system of temperature and humidity fitting functions.

[0066] The condensate purification unit includes a membrane separation purification device, which purifies condensate through a combination of ultrafiltration, nanofiltration, and reverse osmosis. The flue gas water recovery system also includes a purification control system 16. The input parameters of the purification control system 16 are the conductivity of the inlet water, the concentration of characteristic pollutants, and the flow rate of characteristic pollutants. The control parameters of the purification control system 16 are the regulating valve of the purification device and the frequency of the variable frequency pump. The target parameters of the purification control system 16 are the conductivity of the outlet water and the concentration of characteristic pollutants. PID integrated control is implemented using these parameters.

[0067] The negative pressure steam condensation unit includes an air cooler. The water vapor released by the dehumidification module 7 enters the negative pressure steam condensation unit, where it is cooled and condensed by a frequency-controlled air cooler, creating a vacuum. The air cooler lowers the temperature of the dehumidification module 7. The flue gas water recovery system also includes a condensation control system 15. After the water vapor released by the dehumidification module 7 enters the negative pressure steam condensation unit, it is condensed under the control of the condensation control system 15. The input parameters of the condensation control system 15 are the water vapor pressure, the water vapor temperature, and the humidity of the dehumidification module. The control parameter of the condensation control system 15 is the air cooler frequency. These parameters form a PID integrated control.

[0068] The pressures of the flue gas dehumidification unit, the negative pressure regeneration steam recovery unit, the negative pressure steam condensation unit and the condensate purification unit decrease in sequence.

[0069] like Figure 1 As shown, Figure 1 The T in it represents the detection of parameters such as temperature, pressure, speed, and flow rate; Figure 1 The A in the figure stands for analyzer. The specific analysis varies according to the specific location. In the above control system, different control system analysis indicators are different, including humidity, water quality monitoring, water conductivity, pH value detection, etc.

[0070] Example 2

[0071] Those skilled in the art may understand this embodiment as a more specific description of Embodiment 1.

[0072] This embodiment belongs to the field of flue gas water recovery for wet removal of pollutants. This embodiment provides a system and method for recovering water from flue gas for wet removal of pollutants, particularly a flue gas water recovery process for wet removal of pollutants.

[0073] The system of this embodiment includes a coupled flue gas dehumidification unit, a negative pressure regenerative steam recovery unit, a negative pressure steam condensation unit, a condensate purification unit, an adaptive closed thermal coupling energy recovery unit, and an adaptive intelligent control system.

[0074] The specific process of flue gas water recovery is as follows:

[0075] 1) The saturated wet flue gas enters the coupled flue gas dehumidification unit, which is equipped with an adsorption dehumidification module to adsorb water vapor in the flue gas and dry the flue gas for discharge.

[0076] 2) The adsorption saturated dehumidification unit enters the negative pressure regeneration steam recovery unit under the control of the intelligent control system. The unit uses the heat of the adaptive closed thermal coupling energy recovery unit to regenerate the adsorbed water.

[0077] 3) The regenerated water vapor enters the negative pressure steam condensation unit, is cooled to condensed water, and at the same time generates a vacuum degree, which is connected to the negative pressure regeneration steam recovery unit, thereby improving the regeneration efficiency and reducing the regeneration temperature.

[0078] 4) After regeneration, the adsorption and dehumidification module returns to the initial adsorption state, contacts with the flue gas, and adsorbs moisture in the flue gas.

[0079] 5) The condensate enters the condensate purification unit and can reach the desalted water quality after purification. It can be used as boiler make-up water, as circulating cooling water make-up water, or can be deeply treated to reach ultrapure water.

[0080] The intelligent control system includes a temperature and humidity control system C1. Input parameters include flue gas humidity, flue gas temperature, dehumidification module unit temperature, dehumidification module unit humidity, and dehumidification module unit pressure. The control parameter is the contact area efficiency between the dehumidification module working fluid and the flue gas. The target control parameters are the saturated humidity after the dehumidification module unit and the humidity of the flue gas after dehumidification. The present invention includes a coupled flue gas dehumidification unit, which utilizes a mixture of one or more of activated carbon, silica gel, lithium chloride, calcium chloride, and zinc chloride.

[0081] The saturated dehumidification unit enters the negative pressure regeneration steam recovery unit under the control of intelligent control system C1. This unit includes a high-temperature flue gas heat exchanger, heat transfer piping, a heat receiver, and a heat supply device. Through control system C2, this unit supplies heat to the saturated dehumidification module, regenerating the module and releasing steam. The input parameters of control system C2 are the humidity of the dehumidification unit, the pressure of the dehumidification unit, and the pressure of the negative pressure regeneration steam recovery unit. The control parameters are the temperature of the negative pressure regeneration steam recovery unit and the heat input of the negative pressure regeneration steam recovery unit. The target control parameter is the humidity of the dehumidification unit.

[0082] Under the heat-raising conditions of control system C2, the negative pressure regeneration steam recovery unit releases water vapor from the dehumidification module. The water vapor enters the negative pressure steam condensation unit, where it is cooled and condensed by a variable frequency air cooler, creating a vacuum and maintaining the regeneration of the dehumidification module at a low temperature.

[0083] After the water vapor enters the negative pressure steam condensation unit, it condenses under the control system C3. The input parameters of the control system C3 are the water vapor pressure, temperature, and humidity of the dehumidification unit module, and the control parameter is the frequency of the air cooler.

[0084] Water vapor condenses in the negative pressure steam condensation unit and enters the condensate purification unit, which includes a membrane separation purification device. Depending on the application, the condensate is purified through one or a combination of ultrafiltration, nanofiltration, and reverse osmosis processes. The control system C4 of this unit uses input parameters such as the conductivity of the influent, the concentration of characteristic pollutants, and the flow rate. Control parameters include the regulating valve of the purification unit and the frequency of the variable frequency pump. The target control parameters are the conductivity of the effluent and the concentration of characteristic pollutants.

[0085] The dehumidification unit module reduces the temperature under the action of the air cooler.

[0086] In a specific application scenario, a) saturated wet flue gas enters a coupled flue gas dehumidification unit with a humidity equal to the flue gas's saturation humidity, a temperature of approximately 50°C to 60°C, and a saturated water content of approximately 60 to 72 g / m³. This unit is equipped with an adsorption dehumidification module to adsorb water vapor from the flue gas and discharge the dry flue gas directly into the atmosphere. b) The adsorption-saturated dehumidification unit, under the control of an intelligent control system, enters a negative pressure regeneration steam recovery unit. This unit utilizes heat from an adaptive closed thermal coupling energy recovery unit to regenerate the adsorbed water. This unit is connected to a negative pressure steam condensation unit. c) The regenerated water vapor enters the negative pressure steam condensation unit, where it is cooled to condensate, creating a vacuum. This unit is then connected to the negative pressure regeneration steam recovery unit, improving regeneration efficiency and reducing regeneration temperature. d) After regeneration, the adsorption dehumidification module returns to its initial adsorption state, comes into contact with the flue gas, and adsorbs moisture from the flue gas. The condensate enters a condensate purification unit, where it is purified to achieve demineralized water quality and can be used as boiler feed water, circulating cooling water, or undergoes deep treatment to produce ultrapure water.

[0087] Example 3

[0088] Those skilled in the art may understand this embodiment as a more specific description of Embodiment 1.

[0089] This embodiment provides a flue gas water recovery system for wet removal of pollutants, including: a first flue gas duct 1, a flue gas heat collector 2, a flue gas inlet 3, a purification device 4, a purified flue gas duct 5, a heat receiver 6, a dehumidification module unit 7, a second flue gas duct 8, an exhaust chimney 9, a first air cooler 10, a second air cooler 11, a condensate purification unit 12, a temperature and humidity control system 13, a heat control system 14, a condensation control system 15, a purification control system 16, an exhaust port 17, a heat medium transmission pipeline 20, and a heat supply device.

[0090] The first flue gas duct 1 is connected to the flue gas inlet of the flue gas heat exchanger 2. The flue gas inlet 3 on the flue gas heat exchanger 2 is connected to the inlet of the purification device 4. The outlet of the purification device 4 is connected to the inlet of the dehumidification module 7 via the purified flue gas duct 5. The water vapor outlet of the dehumidification module 7 is connected to the inlet of the first air cooler 10 and the inlet of the second air cooler 11. The dry flue gas outlet of the dehumidification module 7 is connected to the exhaust chimney 9 via the second flue gas duct 8. The exhaust chimney 9 is provided with an exhaust port 17. The second flue gas duct 8 is the flue for the dehumidified flue gas. The first flue gas duct 1 is a high-temperature flue gas duct, and the flue gas heat exchanger 2 is a high-temperature flue gas heat exchanger.

[0091] The outlet of the first air cooler 10 and the outlet of the second air cooler 11 are connected to the inlet of the condensate purification unit 12. The first outlet of the condensate purification unit 12 is connected to the spray structure of the purification equipment 4. The first outlet is used to output the discharged concentrated water 19. The second outlet of the condensate purification unit 12 is used to output the purified recovered water 18.

[0092] One end of the heat medium transmission pipeline 20 is connected to the flue gas heat collector 2, and the other end of the heat medium transmission pipeline 20 is connected to the heat receiver 6, which supplies heat to the dehumidification module unit 7 through the heat supply device.

[0093] The first air cooler 10 and the second air cooler 11 constitute a negative pressure steam condensing unit.

[0094] The flue gas heat extractor 2, the heat receiver 6, the heat medium transmission pipeline 20 and the heat supply equipment constitute a negative pressure regenerative steam recovery unit and an adaptive closed thermal coupling energy recovery unit.

[0095] In the present invention, the pressure decreases successively from the flue gas dehumidification unit to the negative pressure regeneration steam recovery unit, the negative pressure steam condensation unit and the condensate purification unit, so no flue gas boosting equipment is required.

[0096] The present invention provides a low-energy-consuming process for recovering water from flue gas for wet removal of pollutants.

[0097] In the description of this application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0098] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A flue gas water recovery system for wet pollutant removal, characterized in that: include: Coupled flue gas dehumidification unit, negative pressure regenerative steam recovery unit, negative pressure steam condensation unit, condensate purification unit, adaptive closed thermal coupling energy recovery unit and control system; The saturated wet flue gas enters the coupled flue gas dehumidification unit, and the coupled flue gas dehumidification unit is provided with a dehumidification module unit (7) for adsorbing water vapor in the saturated wet flue gas and discharging dry flue gas; The dehumidification module unit (7) that has been saturated with adsorption enters the negative pressure regeneration steam recovery unit under the control of the control system. The negative pressure regeneration steam recovery unit utilizes the heat of the adaptive closed thermal coupling energy recovery unit to release the water adsorbed in the dehumidification module unit (7) in the form of water vapor, thereby regenerating the water adsorbed in the dehumidification module unit (7); The regenerated water vapor enters the negative pressure steam condensation unit, is cooled into condensed water, and generates a vacuum degree at the same time. The negative pressure steam condensation unit is connected to the negative pressure regeneration steam recovery unit and can transfer the generated vacuum degree to the negative pressure regeneration steam recovery unit; The dehumidification module unit (7) returns to the initial adsorption state after regeneration, and returns to the coupled flue gas dehumidification unit through the control system, and contacts the saturated wet flue gas again, adsorbing the moisture in the saturated wet flue gas, thereby achieving cyclic adsorption; The condensed water generated by the negative pressure steam condensation unit enters the condensed water purification unit for purification.

2. The flue gas water recovery system for wet pollutant removal according to claim 1 is characterized in that: The dehumidification module unit (7) is a coupled flue gas dehumidification unit, and adopts a mixed substance composed of one or more of activated carbon, silica gel, lithium chloride, calcium chloride, and zinc chloride.

3. The flue gas water recovery system for wet pollutant removal according to claim 1, characterized in that: The control system comprises: a temperature and humidity control system (13); The adsorption-saturated dehumidification module unit (7) enters the negative pressure regeneration steam recovery unit under the control of the temperature and humidity control system (13).

4. The flue gas water recovery system for wet pollutant removal according to claim 3 is characterized in that: The input parameters of the temperature and humidity control system (13) are the humidity of the flue gas, the temperature of the flue gas, the temperature of the dehumidification module unit, the humidity of the dehumidification module unit, and the pressure of the dehumidification module unit; The control parameter of the temperature and humidity control system (13) is the contact area efficiency between the working medium and the flue gas of the dehumidification module unit; The target control parameters of the temperature and humidity control system (13) are the saturated humidity after the dehumidification module unit and the humidity of the flue gas after dehumidification.

5. The flue gas water recovery system for wet pollutant removal according to claim 1, characterized in that: The negative pressure regeneration steam recovery unit comprises: a flue gas heat collector (2), a heat medium transmission pipeline, a heat receiver (6), and a heat supply device; The flue gas heat extractor (2) is used to absorb heat from the incoming high-temperature flue gas and transfer the absorbed heat to the heat receiver (6) through the heat medium transmission pipeline; The heat receiver (6) receives the heat transferred by the flue gas heat extractor (2), and supplies the received heat to the dehumidification module unit (7) through the heat supply device.

6. The flue gas water recovery system for wet pollutant removal according to claim 1, characterized in that: The flue gas water recovery system further includes: a heat control system (14); The negative pressure regeneration steam recovery unit supplies heat to the adsorption saturated dehumidification module unit (7) through the heat control system (14); The negative pressure regeneration steam recovery unit releases the water adsorbed in the dehumidification module unit (7) in the form of water vapor under the heat rising condition of the heat control system (14), thereby being regenerated.

7. The flue gas water recovery system for wet pollutant removal according to claim 6, characterized in that: The input parameters of the heat control system (14) are the humidity of the dehumidification module unit, the pressure of the dehumidification module unit, and the pressure of the negative pressure regeneration steam recovery unit; The control parameters of the heat control system (14) are the temperature of the negative pressure regeneration steam recovery unit and the heat input of the negative pressure regeneration steam recovery unit; The target control parameter of the heat control system (14) is the humidity of the dehumidification module unit.

8. The flue gas water recovery system for wet pollutant removal according to claim 1, characterized in that: The negative pressure steam condensation unit includes: an air cooler; The water vapor released by the dehumidification module unit (7) enters the negative pressure steam condensation unit, and the negative pressure steam condensation unit cools and condenses the water vapor through the air cooler regulated by variable frequency to form a vacuum degree; The dehumidification module unit (7) reduces the temperature under the action of the air cooler.

9. The flue gas water recovery system for wet pollutant removal according to claim 8, characterized in that: The flue gas water recovery system further includes: a condensation control system (15); After the water vapor released by the dehumidification module unit (7) enters the negative pressure steam condensation unit, the water vapor is condensed under the control of the condensation control system (15); The input parameters of the condensation control system (15) are the pressure of water vapor, the temperature of water vapor, and the humidity of the dehumidification module unit; The control parameter of the condensation control system (15) is the frequency of the air cooler.

10. The flue gas water recovery system for wet pollutant removal according to claim 1, characterized in that: The condensate purification unit includes: a membrane separation purification device; The membrane separation purification device purifies the condensate water by one or more combined processes of ultrafiltration, nanofiltration, and reverse osmosis; The flue gas water recovery system also includes: a purification control system (16); The input parameters of the purification control system (16) are the conductivity of the influent, the concentration of the characteristic pollutants, and the flow rate of the characteristic pollutants; The control parameters of the purification control system (16) are the regulating valve and the frequency of the variable frequency pump of the purification device; The target parameters of the purification control system (16) are the conductivity of the outlet water and the concentration of characteristic pollutants.

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