Gas treatment system

Abstract

To provide a gas treatment system capable of controlling the temperature of gas discharged from a wet type electrostatic precipitator.SOLUTION: The gas treatment system 200 includes the wet-type electric dust collection device 320 that removes at least a part of an impurity from a source gas containing a specific ingredient and the impurity and discharges a cleaned gas, the rinse water supplier 330 that supplies rinse water to the wet-type electric dust collection device 320, the thermometer 452 that detects a temperature T1 of the cleaned gas discharged from the wet-type electric dust collection device 320, and the controller 210 that controls a supplied amount T1 of the rinse water based on the temperature R5 of the cleaned gas.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to gas processing systems. [Background technology]

[0002] Exhaust gas treatment equipment that treats exhaust gas discharged from a combustion device is known (see, for example, Patent Document 1). The exhaust gas treatment equipment described in Patent Document 1 includes a desulfurization device that desulfurizes the exhaust gas, and a wet electrostatic precipitator that removes solid matter from the exhaust gas desulfurized by the desulfurization device. The wet electrostatic precipitator includes electrodes that collect the solid matter, and nozzles that spray a cleaning liquid onto the electrodes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-20129 Summary of the Invention [Problem to be solved by the invention]

[0004] In a gas treatment system equipped with a wet electrostatic precipitator, the temperature of the gas discharged from the wet electrostatic precipitator has not been taken into consideration.

[0005] An object of the present disclosure is to provide a gas treatment system that is capable of controlling the temperature of gas discharged from a wet electrostatic precipitator. [Means for solving the problem]

[0006] The gas processing system according to the present disclosure includes a wet electrostatic precipitator that removes at least a portion of the impurities from a raw material gas containing specific components and impurities and discharges a purified gas, a cleaning water supply unit that supplies cleaning water to the wet electrostatic precipitator, a thermometer that detects the temperature of the purified gas discharged from the wet electrostatic precipitator, and a control unit that controls the amount of cleaning water supplied based on the temperature of the purified gas. [Effects of the Invention]

[0007] The present disclosure can provide a gas treatment system that is capable of controlling the temperature of gas discharged from a wet electrostatic precipitator. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram illustrating a gas processing system according to a first embodiment. [Figure 2] FIG. 2 is a schematic view illustrating a pretreatment device according to the first embodiment. [Figure 3] FIG. 2 is a block diagram illustrating an example of a hardware configuration of a preprocessing device according to the first embodiment. [Figure 4] 5 is a flowchart showing the procedure of a control process in the pre-processing device according to the first embodiment. [Figure 5] FIG. 10 is a schematic view illustrating a pretreatment device according to a second embodiment. [Figure 6] FIG. 10 is a block diagram illustrating an example of a hardware configuration of a preprocessing device according to a second embodiment. [Figure 7] 10 is a flowchart showing a control process procedure (part 1) in a pre-processing device according to a second embodiment. [Figure 8] 10 is a flowchart showing a control process procedure (part 2) in the pre-processing device according to the second embodiment. [Figure 9] FIG. 10 is a schematic view illustrating a pretreatment device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a gas processing system according to an embodiment will be described with reference to the accompanying drawings. In this specification and the drawings, substantially identical components are designated by the same reference numerals, and redundant description may be omitted.

[0010] [Gas Processing System 200 According to the First Embodiment] FIG. 1 is a schematic diagram illustrating a gas processing system 200 according to a first embodiment. The gas processing system 200 shown in FIG. 1 is a system that separates carbon dioxide contained in a raw material gas and recovers the carbon dioxide. The raw material gas may be, for example, a combustion exhaust gas discharged from a combustor 10. The raw material gas is not limited to the combustion exhaust gas discharged from the combustor 10, and may be a gas discharged from other equipment. The gas processing system 200 is installed, for example, in a factory, a power plant, a ship, or the like. The installation location of the gas processing system 200 is not particularly limited.

[0011] The gas processing system 200 shown in FIG. 1 includes a separation device 100 that separates carbon dioxide contained in a raw material gas, and a pretreatment device 300 that is provided upstream of the separation device 100. A portion of the raw material gas discharged from the combustor 10 is supplied to the pretreatment device 300. The pretreatment device 300 removes dust (solid matter) contained in the raw material gas and discharges purified gas from which the dust has been removed. The purified gas containing carbon dioxide is supplied to the separation device 100. The pretreatment device 300 can control the temperature of the purified gas supplied to the separation device 100.

[0012] The raw material gas discharged from the combustor 10 is supplied to, for example, an economizer 11. The economizer 11 can generate steam by heat exchange between the raw material gas and boiler water. A portion of the raw material gas discharged from the economizer 11 is supplied to a pretreatment device 300. The remainder of the raw material gas discharged from the economizer 11 may be released into the atmosphere through an exhaust pipe 12.

[0013] [Pretreatment device 300 according to the first embodiment] 2 is a schematic diagram illustrating a pretreatment device 300 according to the first embodiment. As shown in FIG. 2, the pretreatment device 300 includes a wet electrostatic precipitator 320, a cleaning water supply unit 330, a wastewater treatment unit 340, and a controller 210.

[0014] [Source gas supply pipe L311] The pretreatment device 300 includes a raw material gas supply pipe L311 that supplies raw material gas to the wet electrostatic precipitator 320. The raw material gas flows through the raw material gas supply pipe L311 and is supplied to the wet electrostatic precipitator 320.

[0015] [Flowmeter 411] The pretreatment device 300 is equipped with a flow meter 411 that detects the flow rate R2 of the raw material gas supplied to the wet electrostatic precipitator 320. The flow meter 411 detects the flow rate R2 of the raw material gas flowing through the raw material gas supply pipe L311. Data related to the flow rate R2 of the raw material gas detected by the flow meter 411 is input to the controller 210.

[0016] [Thermometer 412] The pretreatment device 300 is equipped with a thermometer 412 that detects the temperature T2 of the raw material gas supplied to the wet electrostatic precipitator 320. The thermometer 412 detects the temperature T2 of the raw material gas flowing through the raw material gas supply pipe L311. Data related to the temperature T2 of the raw material gas detected by the thermometer 412 is input to the controller 210.

[0017] [Cleaning water supply unit 330] The cleaning water supply unit 330 includes a cleaning water supply pipe L331 that supplies cleaning water to the wet electrostatic precipitator 320. The cleaning water supply unit 330 may include a pump 331. The pump 331 is connected to the cleaning water supply pipe L331. The pump 331 transports the cleaning water. The cleaning water flows through the cleaning water supply pipe L331 and is supplied to the wet electrostatic precipitator 320.

[0018] [Flowmeter 431] The cleaning water supply unit 330 is equipped with a flow meter 431 that detects the supply amount R5 of cleaning water supplied to the wet electrostatic precipitator 320. The flow meter 431 detects the supply amount R5 of cleaning water flowing inside the cleaning water supply pipe L331. Data related to the supply amount R5 of cleaning water detected by the flow meter 431 is input to the controller 210.

[0019] [Thermometer 432] The cleaning water supply unit 330 is equipped with a thermometer 432 that detects the temperature T5 of the cleaning water supplied to the wet electrostatic precipitator 320. The thermometer 432 detects the temperature T5 of the cleaning water flowing in the cleaning water supply pipe L331. Data related to the temperature T5 of the cleaning water detected by the thermometer 432 is input to the controller 210.

[0020] [Control valve V331] The cleaning water supply unit 330 is equipped with a control valve V331 that controls the supply amount R5 of cleaning water supplied to the wet electrostatic precipitator 320. The control valve V311 is connected to the cleaning water supply pipe L331, and can control the flow rate (supply amount R5) of cleaning water flowing through the cleaning water supply pipe L331. The control valve V331 is electrically connected to the controller 210. The control valve V331 is driven in accordance with a command signal output from the controller 210. The controller 210 can control the valve opening degree of the control valve V331.

[0021] [Wet electrostatic precipitator 320] The wet electrostatic precipitator 320 removes dust particles (impurities) contained in the raw material gas. The wet electrostatic precipitator 320 is equipped with electrodes that collect dust particles and nozzles that spray cleaning water (cleaning liquid) onto the electrodes. The raw material gas supplied from the raw material gas supply pipe L311 flows through a flow path inside the wet electrostatic precipitator 320. The electrodes are disposed in the flow path through which the raw material gas flows. The dust particles contained in the raw material gas are collected by the electrodes and separated from the raw material gas. The purified gas from which the dust particles have been separated is discharged from the wet electrostatic precipitator 320.

[0022] The nozzle that sprays the cleaning water is disposed above the electrode, for example. The arrangement of the electrode and the nozzle is not particularly limited. The nozzle is connected to a cleaning water supply pipe L331. The cleaning water supplied from the cleaning water supply pipe L331 is discharged from the nozzle and sprayed onto the electrode. The cleaning water washes away dust collected on the electrode. The cleaning water after cleaning the electrode is discharged from the wet electrostatic precipitator 320. The cleaning water after cleaning the electrode may be referred to as "wastewater." The wastewater includes dust and cleaning water. In the wet electrostatic precipitator 320, the cleaning water is continuously discharged from the nozzle. The cleaning water may be intermittently discharged from the nozzle. In the wet electrostatic precipitator 320, it is sufficient that the cleaning water be discharged to clean the electrode and cool the source gas.

[0023] [Wastewater treatment unit 340] The wastewater treatment device 340 includes a wastewater tank 341, a wastewater treatment device 342, a wastewater pipe L341, and a wastewater pipe L342. The wastewater pipe L341 connects the wet electrostatic precipitator 320 and the wastewater tank 341. Wastewater discharged from the wet electrostatic precipitator 320 flows through the wastewater pipe L341 and is supplied to the wastewater tank 341. The wastewater tank 341 stores the wastewater discharged from the wet electrostatic precipitator 320.

[0024] The wastewater treatment device 342 separates impurities (dust, solids) in the wastewater stored in the wastewater tank 341 from the wastewater. For example, the wastewater treatment device 342 treats a portion of the wastewater stored in the wastewater tank 341. The impurities removed from the wastewater are stored in an impurity tank. The wastewater treatment device 342 can return the wastewater after impurity removal to the wastewater tank 341. By removing impurities in the wastewater using the wastewater treatment device 342, the concentration of impurities in the wastewater stored in the wastewater tank 341 can be maintained within a predetermined range.

[0025] The drain pipe L342 is connected to the drain tank 341 and discharges the drainage water stored in the drain tank 341 to the outside of the drain tank 341.

[0026] [Flowmeter 441] The wastewater treatment device 340 may include a flow meter 441 that detects a flow rate R4 of the wastewater discharged from the wet electrostatic precipitator 320. The flow meter 441 detects the flow rate R4 of the wastewater flowing through the wastewater pipe L341. Data related to the flow rate R4 of the wastewater detected by the flow meter 441 is input to the controller 210.

[0027] [Thermometer 442] The wastewater treatment unit 340 includes a thermometer 442 that detects the temperature T4 of the wastewater stored in the wastewater tank 341. Data on the temperature T4 of the wastewater detected by the thermometer 442 is input to the controller 210.

[0028] [Control valve V342] The cleaning water supply unit 330 is equipped with a control valve V342 that controls the amount of wastewater discharged from the wastewater tank 341. The control valve V342 is connected to the drainage pipe L342 and can control the amount of wastewater discharged. The control valve V342 is electrically connected to the controller 210. The control valve V342 is driven in accordance with a command signal output from the controller 210. The controller 210 can control the valve opening degree of the control valve V342.

[0029] [Purified gas exhaust piping L351] The pretreatment device 300 includes a purified gas discharge pipe L351 that discharges purified gas from the wet electrostatic precipitator 320. The purified gas flows through the purified gas discharge pipe L351 and is supplied to the separation device 100. The purified gas discharge pipe L351 is a purified gas supply pipe that supplies purified gas to the separation device 100.

[0030] [Flowmeter 451] The pretreatment device 300 is equipped with a flow meter 451 that detects the flow rate R1 of the purified gas discharged from the wet electrostatic precipitator 320. The flow meter 451 is provided in the purified gas discharge pipe L351. Data related to the flow rate R1 of the purified gas detected by the flow meter 451 is input to the controller 210.

[0031] [Thermometer 452] The pretreatment device 300 is equipped with a thermometer 452 that detects the temperature T1 of the purified gas discharged from the wet electrostatic precipitator 320. The thermometer 452 is provided in the purified gas discharge pipe L351. Data related to the temperature T1 of the purified gas detected by the thermometer 452 is input to the controller 210.

[0032] [Controller 210] Next, the controller 210 of the pretreatment device 300 will be described with reference to Fig. 3. Fig. 3 is a block diagram illustrating the hardware configuration of the pretreatment device 300 according to the first embodiment. As shown in Fig. 3, the controller 210 is electrically connected to a flow meter 411, a thermometer 412, a flow meter 431, a thermometer 432, a flow meter 441, a thermometer 442, a flow meter 451, and a thermometer 452. The controller 210 is electrically connected to a pump 331, a control valve V331, and a control valve V342.

[0033] The controller 210 includes a CPU (Center Processing Unit) 211 and a storage unit 212. The CPU 211 is responsible for overall control of the pretreatment device 300. The CPU 211 receives as input various data detected by a flow meter 411, a thermometer 412, a flow meter 431, a thermometer 432, a flow meter 441, a thermometer 442, a flow meter 451, and a thermometer 452. Other sensors may be connected to the controller 210.

[0034] The storage unit 212 includes a ROM (Read Only Memory) 213 and a RAM (Random Access Memory) 214. The ROM 213 stores various programs for causing the CPU 211 to execute control processes, as well as various data necessary for operation in the preprocessing device 300. The RAM 214 temporarily stores data acquired from the flow meter 411, the thermometer 412, the flow meter 431, the thermometer 432, the flow meter 441, the thermometer 442, the flow meter 451, and the thermometer 452.

[0035] The controller 210 controls the supply amount of cleaning water based on the temperature of the purified gas. The controller 210 controls the supply amount R5 of cleaning water supplied to the wet electrostatic precipitator 320 so that the temperature T1 of the purified gas is within a predetermined temperature range (first reference range). The controller 210 controls the valve opening of the control valve V331 to control the supply amount R5 of cleaning water. The controller 210 increases the supply amount R5 of cleaning water when the temperature T1 of the purified gas exceeds a predetermined determination threshold (upper limit). The controller 210 may decrease the supply amount R5 of cleaning water when the temperature T1 of the purified gas is less than a predetermined determination threshold (lower limit). The controller 210 may control the pump 331 to increase or decrease the supply amount R5 of cleaning water.

[0036] The controller 210 can control the supply amount R5 of cleaning water based on the purified gas temperature T1, the raw gas temperature T2, and the raw gas flow rate R2. The controller 210 may also control the supply amount R5 of cleaning water based on the temperature difference between the purified gas temperature T1 and the raw gas temperature T2.

[0037] The controller 210 may include a calculation unit that calculates the required supply amount of cleaning water to be supplied to the wet electrostatic precipitator 320. The controller 210 can calculate the required supply amount of cleaning water based on the target temperature of the purified gas, the flow rate R2 of the raw gas, and the temperature T5 of the cleaning water. The target temperature of the purified gas may be the target temperature of the purified gas supplied to the separation device 100. The temperature T5 of the cleaning water is the temperature of the cleaning water supplied to the wet electrostatic precipitator 320.

[0038] The controller 210 can increase the supply rate R5 of cleaning water so that it exceeds the required supply rate of cleaning water when the temperature T1 of the purified gas is higher than the target temperature. The controller 210 can decrease the supply rate R5 of cleaning water so that it falls below the required supply rate of cleaning water when the temperature T1 of the purified gas is lower than the target temperature.

[0039] [Control process procedure in the pre-treatment device 300 according to the first embodiment] Next, the control process procedure in the pretreatment device 300 will be described with reference to Fig. 4. Fig. 4 is a flowchart showing the control process procedure in the pretreatment device 300. The controller 210 inputs data from various sensors (step S11). The controller 210 inputs data related to the temperature of the purified gas from the thermometer 452.

[0040] The controller 210 determines whether the purified gas temperature T1 is equal to or greater than a determination threshold value TH1 (the upper limit of a predetermined temperature range) (step S12). If the purified gas temperature T1 is equal to or less than the determination threshold value TH1 (step S12; YES), the controller 210 executes the process of step S14. If the purified gas temperature T1 exceeds the determination threshold value TH1 (step S12; NO), the controller 210 executes the process of step S13.

[0041] In step S13, the controller 210 increases the supply rate R5 of cleaning water to the wet electrostatic precipitator 320. The controller 210 can increase the rotation speed of the pump 331 to increase the supply rate R5 of cleaning water. The controller 210 may also increase the valve opening of the control valve V331 to increase the supply rate R5 of cleaning water. After the processing of step S13, the controller 210 ends this processing.

[0042] In step S14, the controller 210 determines whether the purified gas temperature T1 is equal to or lower than a determination threshold value TH2 (the lower limit value of a predetermined temperature range) (step S14). If the purified gas temperature T1 is equal to or higher than the determination threshold value TH2 (step S14; YES), the controller 210 ends the process here. If the purified gas temperature T1 is lower than the determination threshold value TH2 (step S14; NO), the controller 210 executes the process of step S15.

[0043] In step S15, the controller 210 reduces the supply rate R5 of cleaning water to the wet electrostatic precipitator 320. The controller 210 can reduce the rotation speed of the pump 331 to reduce the supply rate R5 of cleaning water. The controller 210 may also reduce the valve opening of the control valve V331 to reduce the supply rate R5 of cleaning water. After processing step S15, the controller 210 ends this processing.

[0044] [Separation device 100 according to the first embodiment] Next, a separation apparatus 100 according to a first embodiment will be described with reference to Fig. 1. The separation apparatus 100 is disposed downstream of a pretreatment apparatus 300. Purified gas discharged from the pretreatment apparatus 300 is supplied to the separation apparatus 100. The purified gas may be a raw gas in the separation apparatus 100.

[0045] [Separation tank 20] The separation apparatus 100 includes multiple separation tanks 20, 20B. The number of separation tanks is not particularly limited. The separation tank 20 separates carbon dioxide from the raw gas. The raw gas contains carbon dioxide. The separation tank 20 includes, for example, a separation membrane and a container. The separation membrane is housed in the container. The separation tank 20 may include a separation membrane module. The separation membrane is a membrane that selectively allows carbon dioxide to permeate over other components. The separation membrane includes a hollow fiber membrane. The separation membrane may include multiple spiral membranes or may include stacked flat membranes.

[0046] The purified gas supplied to the separation tank 20 is separated into a permeated gas that has permeated the separation membrane and a retentate gas that has not permeated the separation membrane. The permeated gas has a higher carbon dioxide concentration than the retentate gas. The retentate gas has a lower carbon dioxide concentration than the permeate gas.

[0047] The separation tank 20 may separate carbon dioxide from the purified gas by, for example, adsorption. The separation tank 20 may include a physical adsorbent, a solid adsorbent, or a PCP (Porous Coordination Polymer) instead of a separation membrane. The separation tank 20 may separate the raw gas into a first gas and a second gas having a higher carbon dioxide concentration than the first gas. The separation tank 20 may separate at least a portion of the carbon dioxide contained in the purified gas from the purified gas. The retentate gas discharged from the separation tank 20 is, for example, released into the atmosphere. The separation tank 20 is not limited to one including a separation membrane, and may, for example, be one that brings the raw gas into contact with an absorbing liquid (amine solution) to absorb carbon dioxide in the raw gas. The separation apparatus 100 may include an absorption tower that absorbs carbon dioxide in the raw gas into an absorbing liquid and a stripper tower that strips the carbon dioxide absorbed by the absorbing liquid.

[0048] Separation apparatus 100 is equipped with a differential pressure drive mechanism 41 that generates a differential pressure between the upstream side (retentate side) and downstream side (permeate side) of separation tank 20. The permeate gas discharged from separation tank 20 is transferred by differential pressure drive mechanism 41 and supplied to separation tank 20B.

[0049] Separation tank 20B has the same configuration as separation tank 20. Separation tank 20B separates carbon dioxide from the permeate gas discharged from separation tank 20. The permeate gas discharged from the first-stage separation tank 20 contains carbon dioxide. The gas supplied to second-stage separation tank 20B is separated into permeate gas that has permeated the separation membrane of separation tank 20B and retentate gas that has not permeated the separation membrane.

[0050] The separation apparatus 100 is equipped with a differential pressure drive mechanism 41B that generates a differential pressure between the upstream side (non-permeated side) and downstream side (permeated side) of the second-stage separation tank 20B. The permeate gas discharged from the separation tank 20B is transferred by the differential pressure drive mechanism 41B and stored, for example, in a container before being shipped as a product (carbon dioxide gas). The carbon dioxide, which is the permeate gas discharged from the separation tank 20B, may be stored, for example, in a tank.

[0051] [Recycling Department 50] The separation apparatus 100 may include a recycle section 50 that returns the retentate gas discharged from the second-stage separation tank 20B to the supply side of the first-stage separation tank 20. The recycle section 50 includes a recycle pipe L51 and a blower 51.

[0052] The recycle pipe L51 connects the separation tank 20B and the gas mixing header 15. The blower 51 is connected to the recycle pipe L51. The blower 51 blows the retentate gas discharged from the separation tank 20B and transfers it to the gas mixing header 15. The recycle unit 50 may be equipped with another transfer unit, such as a pump, instead of the blower 51.

[0053] The gas mixing header 15 mixes the purified gas supplied from the pretreatment device 300 with the gas supplied from the recycle pipe L51 (the retentate gas in the separation tank 20B), and supplies the gas to the separation tank 20.

[0054] In the separation apparatus 100, the purified gas controlled within a predetermined temperature range by the pretreatment device 300 is supplied, thereby stabilizing the operation of the separation apparatus 100. Furthermore, by supplying the purified gas within a predetermined temperature range to the separation tank 20, it is possible to suppress a decrease in the function of the separation membrane.

[0055] [Actions and Effects of Gas Processing System 200 According to First Embodiment] The gas processing system 200 according to the first embodiment includes a wet electrostatic precipitator 320 that removes at least a portion of the dust particles (impurities) from a raw material gas containing carbon dioxide (specific component) and dust particles and discharges a purified gas, a cleaning water supply unit 330 that supplies cleaning water to the wet electrostatic precipitator 320, a thermometer 452 that detects the temperature T1 of the purified gas discharged from the wet electrostatic precipitator 320, and a controller (control unit) 210 that controls the supply amount R5 of the cleaning water based on the temperature T1 of the purified gas.

[0056] According to such gas processing system 200, by controlling the supply amount R5 of cleaning water supplied to wet electrostatic precipitator 320, it is possible to adjust the temperature T1 of the purified gas discharged from wet electrostatic precipitator 320.

[0057] The gas processing system 200 further includes a separation device 100 that receives a purified gas and separates the purified gas into a first gas and a second gas having a higher carbon dioxide concentration than the first gas, and the controller 210 can control the amount of cleaning water supplied so that the temperature T1 of the purified gas is within a first reference range.

[0058] According to the gas processing system 200 having this configuration, the temperature T1 of the purified gas is controlled within the first reference range, thereby stabilizing the operation of the separation device 100. This makes it possible to improve the carbon dioxide recovery rate in the separation device 100. The first reference range may be determined based on, for example, the performance of the separation membrane. The first reference range may be determined based on, for example, the performance of the absorption liquid.

[0059] Gas processing system 200 may also include a thermometer 412 that detects a temperature T2 of the raw material gas supplied to wet electrostatic precipitator 320, and a flow meter 411 that detects a flow rate R2 of the raw material gas supplied to wet electrostatic precipitator 320. Controller 210 may control the supply rate R5 of cleaning water based on the temperature T1 of the purified gas, the temperature T2 of the raw material gas, and the flow rate R2 of the raw material gas.

[0060] According to gas processing system 200 having this configuration, it is possible to control the supply amount R5 of cleaning water based on the temperature T2 of the raw material gas on the inlet side of wet electrostatic precipitator 320 and the temperature T1 of the purified gas on the outlet side. In gas processing system 200, it is possible to control the supply amount R5 of cleaning water by understanding the temperature change (temperature difference) of the gas in wet electrostatic precipitator 320. In addition, in gas processing system 200, it is possible to control the supply amount R5 of cleaning water by understanding the amount of heat transfer in wet electrostatic precipitator 320.

[0061] Furthermore, gas processing system 200 includes controller (calculation unit) 210 that calculates the required supply amount of cleaning water to be supplied to wet electrostatic precipitator 320, and controller 210 can calculate the required supply amount of cleaning water based on the target temperature of the purified gas, temperature T2 of the raw gas, flow rate R2 of the raw gas, temperature T5 of the cleaning water, and temperature T4 of the wastewater. When temperature T1 of the purified gas is higher than the target temperature (upper limit of a predetermined temperature range), controller 210 may increase supply amount R5 of cleaning water so that it exceeds the required supply amount, and when temperature T1 of the purified gas is lower than the target temperature (lower limit of a predetermined temperature range), controller 210 may decrease supply amount R5 of cleaning water so that it falls below the required supply amount.

[0062] In gas processing system 200 having this configuration, the cleaning water supply rate R5 can be increased or decreased based on the required cleaning water supply rate. When purified gas temperature T1 is within a predetermined temperature range, controller 210 can set cleaning water supply rate R5 to the required supply rate. When purified gas temperature T1 exceeds the upper limit of the predetermined temperature range, controller 210 can increase cleaning water supply rate R5 so that it exceeds the required supply rate. This can lower purified gas temperature T1. When purified gas temperature T1 is below the lower limit of the predetermined temperature range, controller 210 can decrease cleaning water supply rate R5 so that it falls below the required supply rate. This can raise purified gas temperature T1.

[0063] [Gas Processing System 200 According to Second Embodiment] Next, a pretreatment device 300B of a gas processing system 200 according to a second embodiment will be described. FIG. 5 is a schematic diagram illustrating pretreatment device 300B according to the second embodiment. Gas processing system 200 may be provided with pretreatment device 300B shown in FIG. 5 instead of pretreatment device 300. Pretreatment device 300B according to the second embodiment shown in FIG. 5 differs from pretreatment device 300 according to the first embodiment shown in FIG. 2 in that it includes a wastewater recycling unit 360 that recycles wastewater. Note that in the description of the second embodiment, descriptions similar to those of the first embodiment may be omitted.

[0064] [Wastewater Recycling Department 360] The pretreatment device 300B according to the second embodiment has a wastewater recycling unit 360. The wastewater recycling unit 360 can supply wastewater discharged from the wet electrostatic precipitator 320 to the wet electrostatic precipitator 320 as part of the cleaning water. The wastewater recycling unit 360 includes a wastewater recycling pipe L361, a pump 361, and a control valve V361.

[0065] The wastewater recycle pipe L361 connects the wastewater tank 341 and the cleaning water supply pipe L331. The wastewater recycle pipe L361 is connected to the cleaning water supply pipe L331 between the control valve V331 and the wet electrostatic precipitator 320. The pump 361 is connected to the wastewater recycle pipe L361. The pump 361 can transfer a portion of the wastewater stored in the wastewater tank 341 and return it to the cleaning water supply pipe L331.

[0066] [Cleaning water supply pipe L331] The cleaning water supply pipe L331 includes a cleaning water supply pipe L331a located upstream of the junction with the wastewater recycle pipe L361, and a cleaning water supply pipe L331b located downstream of the junction.

[0067] [Control valve V361] The control valve V361 controls the flow rate of wastewater supplied from the wastewater tank 341 to the cleaning water supply pipe L331. The control valve V361 is provided in the wastewater recycle pipe L361. The control valve V361 is electrically connected to the controller 210. The control valve V361 is driven in accordance with a command signal output from the controller 210. The controller 210 can control the valve opening degree of the control valve V361.

[0068] [Pump 331] The pump 331 may be, for example, a water intake pump that takes in water from outside the pretreatment device 300B. The pump 331 is connected to a cleaning water supply pipe L331a. The pretreatment device 300B can mix make-up water taken in from outside with wastewater stored in a wastewater tank 341 and supply the mixed water to the wet electrostatic precipitator 320. The cleaning water supplied to the wet electrostatic precipitator 320 may contain make-up water taken in from outside and wastewater stored in the wastewater tank 341.

[0069] [Flowmeter 433] The cleaning water supply unit 330 is equipped with a flow meter 433 that detects the flow rate R3 of the taken-in makeup water. The flow meter 433 detects the flow rate R3 of the makeup water flowing inside the cleaning water supply pipe L331a. Data relating to the flow rate R3 of the makeup water detected by the flow meter 433 is input to the controller 210.

[0070] [Thermometer 434] The cleaning water supply unit 330 is equipped with a thermometer 434 that detects the temperature T3 of the taken replenishment water. The thermometer 434 detects the temperature T3 of the replenishment water flowing inside the cleaning water supply pipe L331a. Data relating to the temperature T3 of the replenishment water detected by the thermometer 434 is input to the controller 210. [Control valve V331] The control valve V331 is provided in the cleaning water supply pipe L331a and can control the flow rate R3 of the makeup water.

[0071] [Controller 210] Next, the controller 210 of the pretreatment device 300B according to the second embodiment will be described with reference to Fig. 6. Fig. 6 is a block diagram illustrating the hardware configuration of the pretreatment device 300B according to the second embodiment. As shown in Fig. 6, the controller 210 is electrically connected to a pump 361 and a control valve V361.

[0072] The controller 210 can control the supply amount R5 of cleaning water based on the temperature T5 of the cleaning water and the temperature T1 of the purge gas. The controller 210 can control the supply amount R5 of cleaning water based on the temperature T5 of the cleaning water detected by the thermometer 432 and the temperature T1 of the purge gas detected by the thermometer 452.

[0073] The controller 210 can determine the ratio of make-up water and waste water contained in the wash water based on the make-up water temperature T3, the waste water temperature T4, the wash water temperature T5, and the purge gas temperature T1. For example, if the make-up water temperature T3 is lower than the waste water temperature T4, the controller 210 may increase the ratio of make-up water contained in the wash water and decrease the wash water temperature T3. For example, if the waste water temperature T4 is lower than the make-up water temperature T3, the controller 210 may increase the ratio of waste water contained in the wash water and decrease the wash water temperature T5.

[0074] The controller 210 can increase or decrease the ratio of makeup water by changing the valve opening of the control valve V331. The controller 210 can increase or decrease the ratio of makeup water by controlling the rotation speed of the pump 331.

[0075] The controller 210 can increase or decrease the ratio of wastewater by changing the valve opening of the control valve V361. The controller 210 can increase or decrease the ratio of wastewater by controlling the rotation speed of the pump 361. The controller 210 may determine the ratio of wastewater contained in the cleaning water supplied to the wet electrostatic precipitator 320 based on the temperature T1 of the purified gas. The controller 210 may determine the ratio of wastewater contained in the cleaning water based on the temperature T4 of the wastewater discharged from the wet electrostatic precipitator 320. When the temperature T1 of the purified gas is high, the temperature T4 of the wastewater discharged from the wet electrostatic precipitator 320 also becomes high.

[0076] [Control process procedure (part 1) in the pre-treatment device 300B according to the second embodiment] Next, the control process procedure (part 1) in pretreatment device 300B will be described with reference to Fig. 7. Fig. 7 is a flowchart showing the control process procedure in pretreatment device 300B. Controller 210 inputs data from various sensors (step S21). Controller 210 inputs data related to the temperature T1 of the purified gas from thermometer 452.

[0077] The controller 210 determines whether the purified gas temperature T1 is equal to or greater than a determination threshold value TH1 (the upper limit of a predetermined temperature range) (step S22). If the purified gas temperature is equal to or less than the determination threshold value TH1 (step S22; YES), the controller 210 ends the process here. If the purified gas temperature T1 exceeds the determination threshold value TH1 (step S22; NO), the controller 210 executes the process of step S23.

[0078] In step S23, the controller 210 sets the first set temperature Ts1. The controller 210 can set the first set temperature Ts1 based on an operation input by the user.

[0079] Next, controller 210 determines whether the flush water is solely replenishment water (step S24). Controller 210 can determine the proportion of replenishment water contained in the flush water, for example, based on the detection results from flow meter 431 and flow meter 433. Controller 210 may also determine whether the flush water is solely replenishment water based on the valve opening of control valve V361. If control valve V361 is fully closed, it may be determined that the flush water is solely replenishment water.

[0080] If the flush water is only replenishment water (step S24; YES), the controller 210 executes the process of step S25. If the flush water includes wastewater (step S24; NO), the controller 210 executes the process of step S26.

[0081] In step S25, the controller 210 calculates the required supply amount Rw of cleaning water using the temperature T3 of the replenishment water. The controller 210 calculates the required supply amount Rw using the first set temperature Ts1, the temperature T2 of the raw material gas, the temperature T3 of the replenishment water, the temperature T4 of the wastewater, and the flow rate R2 of the raw material gas.

[0082] The controller 210 can calculate the required heat removal amount Qg using the following formula (1).

number

[0083] Here, "Cg" is the specific heat of the source gas, "Rg" is the flow rate R2 of the source gas, and "ΔT" is the difference between the temperature T2 of the source gas and the first set temperature Ts1.

[0084] The controller 210 calculates the required supply amount of cleaning water Rw using the following formula (2).

number

[0085] Here, "Cw" is the specific heat of the cleaning water, and "ΔT" is the difference between the temperature T4 of the wastewater and the temperature T3 of the replenishment water.

[0086] Next, the controller 210 controls the supply rate R5 of cleaning water (step S27). The controller 210 controls the flow rate R3 of replenishment water so that the flow rate R3 of replenishment water is equal to or greater than the required supply rate Rw. The controller 210 controls the pump 331 or the control valve V331 to control the flow rate R3 of replenishment water. After step S27 is completed, the controller 210 ends this processing.

[0087] In step S26, the controller 210 calculates the required supply amount Rw of cleaning water using the temperature T5 of the cleaning water after mixing. The controller 210 calculates the required supply amount Rw using the first set temperature Ts1, the temperature T2 of the raw material gas, the temperature T4 of the wastewater, the temperature T5 of the cleaning water, and the flow rate R2 of the raw material gas.

[0088] The controller 210 calculates the required supply amount of cleaning water Rw using the following equation (3).

number

[0089] Next, the controller 210 controls the supply rate R5 of cleaning water (step S28), controlling the flow rate R3 of the cleaning water so that the flow rate R3 of the cleaning water is equal to or greater than the required supply rate Rw. The controller 210 may also control the flow rate R3 of the cleaning water and the rate of drainage so that the supply rate R5 of cleaning water is equal to or greater than the required supply rate Rw (step S28). The controller 210 may also control the flow rate R3 of the cleaning water or the rate of drainage so that the supply rate R5 of cleaning water is equal to or greater than the required supply rate Rw (step S28). The controller 210 controls the pump 331 or the control valve V331 to control the flow rate R3 of the cleaning water. After step S28 is completed, the controller 210 ends the processing here.

[0090] [Control Process Procedure (Part 2) in Pre-processing Device 300B According to Second Embodiment] Next, the control process procedure (part 2) in the preprocessing device 300B will be described with reference to Fig. 8. Fig. 8 is a flowchart showing the control process procedure in the preprocessing device 300B. The controller 210 may execute the process shown in Fig. 8 instead of the process shown in Fig. 7. The process shown in Fig. 8 executes the processes of steps S31 to S33 in addition to the process shown in Fig. 7. Note that steps S23 to S28 are omitted in Fig. 8. The processes of steps S21 to S28 are the same as those shown in Fig. 7.

[0091] In step S22 shown in FIG. 8, if the temperature T1 of the purified gas is equal to or lower than the determination threshold value TH1 (step S22; YES), the controller 210 executes the process of step S31.

[0092] In step S31, the controller 210 determines whether the purified gas temperature T1 is equal to or less than 90% of the determination threshold TH1. If the purified gas temperature T1 is equal to or less than 90% of the determination threshold TH1 (step S31; YES), the controller 210 ends this process. If the purified gas temperature T1 is equal to or less than 90% of the determination threshold TH1, the possibility that the purified gas temperature T1 will exceed the determination threshold TH1 is low, and therefore no change in control is executed. If the purified gas temperature T1 exceeds 90% of the determination threshold TH1 (step S31; NO), the controller 210 executes the process of step S32. Note that the above "90%" is an example, and may be, for example, "95%," "85%," or another value. In step S31, the controller 210 may make the determination based on a determination threshold TH3 that is lower than the determination threshold TH1. By making the determination in step S31, the controller 210 can determine whether or not there is a possibility that the temperature T1 of the purified gas will exceed the determination threshold value TH1 after a certain period of time has elapsed.

[0093] In step S32, the controller 210 determines whether the wastewater temperature T4 is equal to or lower than the make-up water temperature T3. If the wastewater temperature T4 is equal to or lower than the make-up water temperature T3 (step S32; YES), the controller 210 ends this process. If the wastewater temperature T4 is lower than the make-up water temperature T3, the purified gas temperature T1 is unlikely to exceed the determination threshold TH1, so no change in control is executed here. If the wastewater temperature T4 exceeds the make-up water temperature T3 (step S32; NO), the controller 210 executes the process of step S33.

[0094] In step S33, the controller 210 performs control to reduce the circulation ratio of wastewater. The "circulation ratio of wastewater" may also be the "ratio of wastewater contained in cleaning water." If the temperature T4 of wastewater exceeds the temperature T3 of make-up water, an increase in the temperature T1 of the purified gas is expected. Therefore, the circulation ratio of wastewater is reduced and the ratio of make-up water is increased, thereby lowering the temperature T5 of the cleaning water. This makes it possible to lower the temperature T1 of the purified gas. After performing the process of step S33, the controller 210 ends this process.

[0095] [Actions and Effects of Gas Processing System 200 According to Second Embodiment] Gas processing system 200 according to the second embodiment also achieves the same effects as gas processing system 200 according to the first embodiment. In gas processing system 200 according to the second embodiment, the cleaning water includes make-up water that is water taken in from the outside, cleaning water supply unit 330 has thermometer 432 that detects temperature T5 of the cleaning water supplied to wet electrostatic precipitator 320 and flow meter 431 that detects supply amount R5 of cleaning water supplied to wet electrostatic precipitator 320, and controller 210 controls supply amount R5 of cleaning water based on temperature T5 of the cleaning water and temperature T1 of the purified gas.

[0096] According to the gas processing system 200 configured as described above, water taken from outside can be supplied as cleaning water to the wet electrostatic precipitator 320. The outside water may be seawater, river water, lake water, groundwater, or other water. The gas processing system 200 may use water treated in a seawater desalination treatment plant as cleaning water.

[0097] The gas processing system 200 may also include a wastewater treatment device 342 that treats at least a portion of the dust (impurities) in the wastewater discharged from the wet electrostatic precipitator 320, and a wastewater recycling pipe (recycle flow path) L361 that returns at least a portion of the wastewater treated by the wastewater treatment device 342 to the wet electrostatic precipitator 320.

[0098] According to the gas processing system 200 having this configuration, the wastewater discharged from the gas processing system 200 can be reused as cleaning water. This reduces the amount of wastewater to be disposed of externally. In addition, the flow rate R3 of make-up water taken from the outside can be reduced. For example, when seawater is taken in and used, a seawater desalination system must be used. Therefore, by reducing the amount of water taken in, it is possible to reduce the installation space for ancillary equipment such as the seawater desalination system. In addition, by reducing the amount of water taken in, it is possible to reduce the power costs for ancillary equipment such as the seawater desalination system. In the gas processing system 200, an operation may be performed in which all of the wastewater is supplied to the wet electrostatic precipitator 320 as cleaning water.

[0099] The gas processing system 200 may also include a thermometer 434 for detecting the temperature T3 of the make-up water and a thermometer 442 for detecting the temperature T4 of the wastewater, and the controller 210 may determine the ratio of make-up water and wastewater contained in the cleaning water based on the temperature T3 of the make-up water, the temperature T4 of the wastewater, the temperature T5 of the cleaning water, and the temperature T1 of the purified gas.

[0100] According to the gas processing system 200 having this configuration, by changing the ratio of make-up water and wastewater in the cleaning water, it is possible to change the temperature of the cleaning water supplied to the wet electrostatic precipitator 320. This makes it possible to control the temperature T1 of the purified gas by changing the temperature of the cleaning water while reusing the wastewater.

[0101] [Gas Processing System 200 According to the Third Embodiment] Next, a pretreatment device 300C of a gas processing system 200 according to a third embodiment will be described. FIG. 9 is a schematic diagram illustrating pretreatment device 300C according to the third embodiment. Gas processing system 200 may be provided with pretreatment device 300C shown in FIG. 9 instead of pretreatment device 300. Pretreatment device 300C according to the third embodiment shown in FIG. 9 differs from pretreatment device 300B according to the second embodiment shown in FIG. 5 in that pretreatment device 300C according to the third embodiment shown in FIG. 9 is provided with a cooler 345 that cools the wastewater discharged from wet electrostatic precipitator 320. Note that in the description of the third embodiment, descriptions similar to those of the first and second embodiments may be omitted.

[0102] [Cooler 345] The pretreatment device 300C according to the third embodiment includes a cooler 345 provided in the drainage pipe L341. The cooler 345 cools the drainage water discharged from the wet electrostatic precipitator 320 by exchanging heat between the drainage water and a refrigerant. The refrigerant may be cooling water. The controller 210 can control the amount of heat transfer in the cooler 345. The controller 210 can control the temperature of the drainage water by controlling the flow rate and temperature of the refrigerant supplied to the cooler 345.

[0103] The gas processing system 200 including the pretreatment device 300C according to the third embodiment also achieves the same effects as the gas processing system 200 according to the above embodiments. In the gas processing system 200 according to the third embodiment, the temperature of the wastewater can be controlled by the cooler 345. As a result, the temperature T5 of the cleaning water may be adjusted by controlling the temperature T4 of the wastewater. Furthermore, in the gas processing system 200, the temperature of the wastewater discharged to the outside can be controlled by using the cooler 345. The pretreatment device 300C prevents high-temperature wastewater from being discharged to the outside.

[0104] The controller 210 may control the amount of heat transfer (amount of heat removal) in the cooler 345 based on, for example, the temperature T1 of the purified gas and the temperature T4 of the wastewater.

[0105] [Gas Processing System 200 According to Fourth Embodiment] Next, a pretreatment device 300 of a gas treatment system 200 according to a fourth embodiment will be described. The pretreatment device 300 according to the fourth embodiment may include a cooler that cools the wastewater flowing through the wastewater recycle pipe L361. The controller 210 can control the temperature of the wastewater returned to the cleaning water supply pipe L331 by controlling the flow rate and temperature of the refrigerant supplied to the cooler.

[0106] Gas processing system 200 including pretreatment device 300 according to the fourth embodiment also achieves the same effects as gas processing system 200 according to the above embodiments. In pretreatment device 300 according to the fourth embodiment, the flow rate of the refrigerant can be reduced compared to a configuration including cooler 345 that cools the wastewater flowing through wastewater pipe L341. Therefore, the power cost for operating the cooler can be reduced.

[0107] [Pre-processing device 300 according to Modification 1] The pretreatment device 300 according to the first modification may further include a pH sensor for measuring the pH of the wastewater and a pH adjuster supply device for supplying a pH adjuster to the wastewater. The controller 210 can control the amount of pH adjuster supplied based on the value measured by the pH sensor so that the pH of the wastewater is 8.0 or less.

[0108] The pH sensor is provided in the wastewater tank 341 and can measure the pH of the wastewater stored in the wastewater tank. The pH adjuster adding device can add a pH adjuster to the wastewater stored in the wastewater tank.

[0109] The exhaust gas used as the raw material gas contains trace amounts of SOx. The SOx in the raw material gas is absorbed by the wash water, which may increase the acidity of the wastewater. When the wastewater is reused, the acidity of the wastewater may increase. On the other hand, if the wastewater becomes alkaline (pH 8.0 or higher) and is supplied to the wet electrostatic precipitator 320, causing the wash water to become alkaline, there is a risk that the electrodes of the wet electrostatic precipitator 320 will corrode.

[0110] The pretreatment device 300 according to the first modification is capable of adjusting the pH of the wastewater, thereby reducing the risk of corrosion of the electrodes in the wet electrostatic precipitator 320. This reduces the maintenance cost of the wet electrostatic precipitator 320 and improves the reliability of the device. The pretreatment device 300 according to the first modification reduces the risk of corrosion in an environment where cleaning water containing wastewater flows.

[0111] [Pre-processing device 300 according to modification 2] The pretreatment device 300 according to the second modification may include a heater for heating the purified gas. The heater heats the purified gas flowing through the purified gas discharge pipe L351. This reduces the relative humidity of the purified gas supplied to the separation device 100.

[0112] The heater may include a heater that heats the purified gas. The heater may heat the purified gas by exchanging heat between the purified gas and the exhaust gas, which is the raw material gas of the pretreatment device 300. By controlling the temperature of the purified gas with the heater, the temperature of the purified gas supplied to the separation device 100 can be controlled within a predetermined temperature range.

[0113] [Pre-processing device 300 according to modification 3] The pretreatment device 300 according to the third modification may include a dehumidifier that dehumidifies the purified gas. This dehumidifier dehumidifies the purified gas flowing through the purified gas discharge pipe L351. This allows the temperature of the purified gas discharged from the wet electrostatic precipitator 320 to be set high, and the purified gas to be dehumidified by the dehumidifier. This allows the supply amount R5 of cleaning water to be reduced.

[0114] The dehumidifier has, for example, an adsorbent that adsorbs moisture. The pretreatment device 300 according to the third modification may have an adsorbent regeneration device that regenerates the adsorbent by exchanging heat between the raw material gas and the adsorbent.

[0115] [Pre-processing device 300 according to modification 4] The pretreatment device 300 according to the fourth modification may include a filter that is provided downstream of the wet electrostatic precipitator 320 and that captures dust remaining in the purified gas. The filter is provided, for example, in the purified gas discharge pipe L351. The filter may be one that captures dust of a different size than the dust captured by the wet electrostatic precipitator 320. The filter may be a bag filter, a HEPA filter, or another filter. The pretreatment device 300 according to the fourth modification can capture dust of a different size than the dust captured by the wet electrostatic precipitator 320.

[0116] It should be noted that the present invention is not limited to the configurations shown here, and other embodiments may be possible in which other components are combined with the configurations described in the above embodiments. In this regard, the present invention can be modified within the scope of the present invention, and can be appropriately determined depending on the application form.

[0117] In the separation device according to the embodiment, there is no limitation on the number of separation tanks 20. The separation device 100 may include one separation tank 20, or may include a plurality of separation tanks 20, 20B.

[0118] There are no particular limitations on the number and arrangement of flow meters and thermometers in gas processing system 200. The judgment thresholds in the control process are set appropriately based on past operating data, test data, and the like.

[0119] In the gas processing system 200, the raw gas is not limited to combustion exhaust gas, but may be other gases such as natural gas. The specific component contained in the raw gas is not limited to "carbon dioxide," but may be hydrocarbon gas or other components. The impurities are not limited to dust, but may be other solids. The device installed downstream of the pretreatment device 300 is not limited to the separation device 100, but may be a storage facility for storing purified gas, or other devices. [Explanation of symbols]

[0120] 100: Separation device, 200: Gas treatment system, 210: Controller (control unit, calculation unit), 300, 300B, 300C: Pretreatment device, 320: Wet electrostatic precipitator, 330: Cleaning water supply unit, 342: Wastewater treatment device, 345: Cooler, 411: Flow meter (raw gas flow rate R2), 412: Thermometer (raw gas temperature T2), 433: Flow meter (make-up water flow rate R3), 434: Thermometer (make-up water temperature T3), 442: Thermometer (wastewater temperature T4), 451: Flow meter (purified gas flow rate R1), 452: Thermometer (purified gas temperature T1), L361: Wastewater recycle piping (recycle flow path).

Claims

1. a wet electrostatic precipitator that removes at least a portion of the impurities from a raw material gas containing a specific component and impurities and discharges a purified gas; a cleaning water supply unit that supplies cleaning water to the wet electrostatic precipitator; a thermometer for detecting the temperature of the purified gas discharged from the wet electrostatic precipitator; a control unit that controls the supply amount of the cleaning water based on the temperature of the purified gas.

2. The method further includes a separation device to which the purified gas is supplied and which separates the purified gas into a first gas and a second gas having a higher concentration of the specific component than the first gas, The gas processing system according to claim 1 , wherein the control unit controls the supply amount of the cleaning water so that the temperature of the purified gas falls within a first reference range.

3. a thermometer for detecting the temperature of the raw material gas supplied to the wet electrostatic precipitator; a flow meter for detecting a flow rate of the raw material gas supplied to the wet electrostatic precipitator; 2. The gas processing system according to claim 1, wherein the control unit controls the supply amount of the cleaning water based on the temperature of the purified gas, the temperature of the raw material gas, and the flow rate of the raw material gas.

4. a thermometer for detecting the temperature of the wastewater discharged from the wet electrostatic precipitator; a calculation unit that calculates a required supply amount of the cleaning water to be supplied to the wet electrostatic precipitator, the calculation unit calculates a required supply amount of the cleaning water based on the target temperature of the purified gas, the temperature of the raw material gas, the flow rate of the raw material gas, the temperature of the cleaning water, and the temperature of the wastewater; The control unit When the temperature of the purified gas is higher than the target temperature, increasing the supply amount of the cleaning water so that it exceeds the required supply amount; 4. The gas processing system according to claim 3, wherein when the temperature of the purified gas is lower than the target temperature, the supply amount of the cleaning water is reduced so as to be below the required supply amount.

5. The cleaning water includes replenishment water, which is water taken from the outside, The cleaning water supply unit a thermometer for detecting the temperature of the cleaning water supplied to the wet electrostatic precipitator; a flow meter for detecting the amount of cleaning water supplied to the wet electrostatic precipitator; The gas processing system according to claim 1 , wherein the control unit controls the supply amount of the cleaning water based on the temperature of the cleaning water and the temperature of the purified gas.

6. a wastewater treatment device for treating at least a portion of the impurities in the wastewater discharged from the wet electrostatic precipitator; 6. The gas treatment system according to claim 5, further comprising a recycle flow path that returns at least a portion of the wastewater treated by the wastewater treatment device to the wet electrostatic precipitator.

7. a thermometer for detecting the temperature of the replenishment water; a thermometer for detecting the temperature of the wastewater; 7. The gas processing system according to claim 6, wherein the control unit determines the ratio of the makeup water and the wastewater contained in the cleaning water based on the temperature of the makeup water, the temperature of the wastewater, the temperature of the cleaning water, and the temperature of the purified gas.

8. The gas processing system according to claim 6 , further comprising a cooler that cools the wastewater discharged from the wet electrostatic precipitator.

9. The gas processing system of claim 8 , wherein the cooler cools the wastewater flowing through the recycle flow path.

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