Exhaust gas treatment system, power generation equipment equipped therewith, and exhaust gas treatment method

Abstract

To provide an exhaust gas treatment system which can suppress increase in absorption liquid consumption in a carbon dioxide recovery device while reducing power used in a process of treating exhaust gas, a power generation facility comprising the same, and an exhaust gas treatment method.SOLUTION: An exhaust gas treatment system comprises: dust collection equipment which includes a NOx removal layer supporting a NOx removal catalyst and through which exhaust gas passes; and a carbon dioxide recovery device which is positioned on a downstream side in an exhaust gas flow direction with respect to the dust collection equipment. The exhaust gas is supplied to the carbon dioxide recovery device from the dust collection equipment while maintaining the condition below an outlet gas temperature of the dust collection equipment.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to an exhaust gas treatment system, a power generation facility including the same, and an exhaust gas treatment method.

Background Art

[0002] For example, Patent Document 1 discloses a conventional exhaust gas treatment system introduced into facilities such as waste incineration plants. The exhaust gas treatment system includes a boiler that recovers heat from the exhaust gas from an incinerator, a desuperheater that cools the exhaust gas, a dust collector that removes dust from the exhaust gas, a reheater that reheats the exhaust gas, a catalytic reaction tower that performs denitration on the exhaust gas reheated by the reheater with a denitration catalyst installed therein, and a chimney.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the exhaust gas treatment system as described above, a carbon dioxide recovery device capable of recovering carbon dioxide contained in the exhaust gas may be introduced. For example, the power within the facility where the exhaust gas treatment system is introduced is used for the carbon dioxide recovery device. Therefore, there is a demand to reduce the power used in the process of treating the exhaust gas in the system. Further, when the treatment of the exhaust gas is insufficient, the amount of impurities contained in the exhaust gas increases, and as a result, the consumption amount of the absorption liquid used in the carbon dioxide recovery device may increase.

[0005] This disclosure was made to solve the above problems and aims to provide an exhaust gas treatment system, a power generation facility equipped therewith, and an exhaust gas treatment method that can reduce the power used in the exhaust gas treatment process while suppressing an increase in the consumption of absorbent liquid in a carbon dioxide recovery device. [Means for solving the problem]

[0006] The exhaust gas treatment system according to this disclosure includes a denitrification layer on which a denitrification catalyst is supported, a dust collection facility through which exhaust gas passes, and a carbon dioxide recovery device located downstream of the dust collection facility in the direction of the exhaust gas flow. A sensor comprising: a first heat recovery unit located upstream of the dust collection equipment in the flow direction of the exhaust gas and for heat exchange between the exhaust gas and a heat transfer medium; a first thermometer capable of detecting the temperature of the exhaust gas flowing between the first heat recovery unit and the dust collection equipment; and a second thermometer capable of detecting the temperature of the exhaust gas flowing between the dust collection equipment and the carbon dioxide recovery device; and a control device that controls the amount of the heat transfer medium supplied to the first heat recovery unit based on the detection results of one or more of the first and second thermometers and a gas temperature threshold. The system is equipped with such a mechanism, and the exhaust gas is supplied from the dust collection equipment to the carbon dioxide recovery device while maintaining a temperature below the outlet gas temperature of the dust collection equipment. Furthermore, the exhaust gas treatment system according to this disclosure includes a denitrification layer on which a denitrification catalyst is supported, a dust collection facility through which the exhaust gas passes, a carbon dioxide recovery device located downstream of the dust collection facility in the direction of the exhaust gas flow, a first heat recovery device located upstream of the dust collection facility in the direction of the exhaust gas flow and which exchanges heat between the exhaust gas and a heat transfer medium, a bypass line that can merge at least a portion of the exhaust gas flowing into the first heat recovery device with the exhaust gas flowing between the first heat recovery device and the dust collection facility without passing through the first heat recovery device, and the bypass line is arranged in the bypass line. The system includes a flow regulator capable of adjusting the flow rate of the exhaust gas flowing through the intake, a sensor having one or more of the following: a first thermometer capable of detecting the temperature of the exhaust gas flowing between the first heat recovery unit and the dust collection unit, and a second thermometer capable of detecting the temperature of the exhaust gas flowing between the dust collection unit and the carbon dioxide recovery device, and a control device that controls the opening degree of the flow regulator based on the detection result of one or more of the first and second thermometers and a gas temperature threshold, wherein the exhaust gas is supplied from the dust collection unit to the carbon dioxide recovery device while maintaining a state at or below the outlet gas temperature of the dust collection unit.

[0007] The power generation equipment relating to this disclosure is a power generation equipment that generates electricity by incinerating materials, comprising: an incinerator in which the materials are incinerated; a boiler located upstream of the dust collection equipment in the direction of the exhaust gas flow and to which the exhaust gas generated in the incinerator is supplied; and the exhaust gas treatment system into which the exhaust gas that has passed through the boiler is introduced. 、 The carbon dioxide recovery apparatus comprises a cooling tower for cooling the exhaust gas, an absorption tower for absorbing the carbon dioxide contained in the cooled exhaust gas into an absorbent liquid, a regeneration tower for heating the absorbent liquid that has absorbed the carbon dioxide using a reboiler supplied with a heat transfer medium and separating the carbon dioxide from the absorbent liquid, and a reclaimer for dividing the absorbent liquid from the regeneration tower into a first liquid in which impurities are concentrated and a second liquid from which impurities have been separated. The aforementioned exhaust gas treatment system is The first liquid from the reclaimer of To be supplied into the incinerator It is equipped with a reducing agent introduction line.

[0008] The exhaust gas treatment method relating to this disclosure is: Using the exhaust gas treatment system described above A method for treating exhaust gases, before While maintaining a state below the outlet gas temperature of the dust collection equipment, the carbon dioxide is transferred from the dust collection equipment to the carbon dioxide recovery device. The aforementioned exhaust gas to supply Furthermore, the amount of the heat transfer medium supplied to the first heat recovery unit is controlled based on the detection results of one or more of the first and second thermometers and a gas temperature threshold, including Furthermore, the exhaust gas treatment method according to this disclosure is an exhaust gas treatment method using the above-described exhaust gas treatment system, and includes supplying the exhaust gas from the dust collection equipment to the carbon dioxide recovery device while maintaining a state at or below the outlet gas temperature of the dust collection equipment, and controlling the opening degree of the flow regulator based on the detection result of one or more of the first thermometer and the second thermometer and a gas temperature threshold.

Advantages of the Invention

[0009] According to the present disclosure, it is possible to provide an exhaust gas treatment system that can suppress an increase in the consumption amount of an absorption liquid in a carbon dioxide recovery device while reducing the power used in the process of treating exhaust gas, a power generation facility including the same, and an exhaust gas treatment method.

Brief Description of the Drawings

[0010] [Figure 1] It is a diagram showing the configuration of a power generation facility according to the first embodiment of the present disclosure. [Figure 2] It is a diagram schematically showing the temperature change of exhaust gas flowing through an exhaust gas flow path. [Figure 3] It is a functional block diagram of a control device according to the first embodiment of the present disclosure. [Figure 4] It is a flowchart showing an example of the operation of a control device according to the first embodiment of the present disclosure. [Figure 5] It is a flowchart showing an example of the operation of a control device according to the first embodiment of the present disclosure. [Figure 6] It is a diagram showing a part of the configuration of a power generation facility according to the second embodiment of the present disclosure. [Figure 7] It is a functional block diagram of a control device according to the second embodiment of the present disclosure. [Figure 8] It is a flowchart showing an example of the operation of a control device according to the second embodiment of the present disclosure. [Figure 9] It is a diagram showing the configuration of a power generation facility according to the third embodiment of the present disclosure. [Figure 10] It is a hardware configuration diagram showing the configuration of a computer according to an embodiment of the present disclosure.

Modes for Carrying Out the Invention

[0011] Hereinafter, with reference to the accompanying drawings, embodiments for implementing an exhaust gas treatment system, a power generation facility, and an exhaust gas treatment method according to the present disclosure will be described.

[0012] <First Embodiment> The power generation facility is, for example, a plant that incinerates municipal waste, industrial waste, biomass, or the like as incineration objects and performs waste power generation by utilizing the heat of the exhaust gas generated by incinerating the incineration objects. As shown in FIG. 1, the power generation facility 1000 includes a waste treatment system 200, an exhaust gas treatment system 100, a power generation system 300, a sensor 400, and a control device 500.

[0013] (Waste Treatment System) The waste treatment system 200 is a system that incinerates incineration objects in the power generation facility 1000. The waste treatment system 200 includes an incinerator 10 and a waste heat recovery boiler 11 (boiler).

[0014] (Incinerator) The incinerator 10 in the present embodiment is a stoker-type incinerator. The incinerator 10 is a furnace that burns incineration objects while conveying them inside. Along with the combustion of the incineration objects by the incinerator 10, exhaust gas EG is generated from the incinerator 10. The generated exhaust gas EG is sent to the exhaust gas treatment system 100 connected to the upper part of the incinerator 10. The incinerator 10 has a furnace body 1, a fuel supply mechanism 2, and a firebox 3.

[0015] The furnace body 1 is the main body part of the incinerator 10. The furnace body 1 defines a space inside for burning incineration objects. Inside the furnace body 1, incineration objects are conveyed while burning. The incineration objects that have been incinerated into ash inside the furnace body 1 are discharged to the outside of the furnace body 1. The fuel supply mechanism 2 receives incineration objects from outside the incinerator 10 and supplies the received incineration objects to the inside of the furnace body 1. The firebox 3 extends upward from the upper part of the furnace body 1. The exhaust gas EG generated by the combustion of incineration objects inside the furnace body 1 is sent to the waste heat recovery boiler 11 through the firebox 3.

[0016] (Waste heat recovery boiler) The waste heat recovery boiler 11 is a device that generates steam by heating the supplied water (feedwater to the waste heat recovery boiler 11) through heat exchange between the exhaust gas EG introduced from the furnace 3 and water supplied from the outside. In this embodiment, the waste heat recovery boiler 11 recovers heat from the exhaust gas EG from the furnace 3 and uses this heat to generate steam (main steam) to drive the steam turbine 31 of the power generation system 300.

[0017] Although detailed illustrations are omitted, the waste heat recovery boiler 11 consists of a boiler frame and heat transfer tubes etc. arranged within this boiler frame. Exhaust gas EG from the furnace 3 is introduced into the boiler frame. The exhaust gas EG introduced into the boiler frame is cooled by heat exchange with water introduced from the outside via the heat transfer tubes inside the boiler frame. Meanwhile, the water introduced into the waste heat recovery boiler 11 is heated by the exhaust gas EG and turned into steam. The exhaust gas EG that has completed heat exchange in the waste heat recovery boiler 11 is introduced into the exhaust gas treatment system 100.

[0018] (Exhaust gas treatment system) The exhaust gas treatment system 100 is a system for treating exhaust gas EG generated in the waste treatment system 200. The exhaust gas treatment system 100 in this embodiment includes an exhaust gas flow path 12, a first heat recovery unit 13, a dust collection device 14, a second heat recovery unit 15, a carbon dioxide recovery device 16, a reducing agent supply unit 19, an activated carbon supply unit 20, an alkaline powder supply unit 21, an alkaline agent supply unit 22, a chimney 17, and an outlet flow path 18.

[0019] (Exhaust gas flow path) The exhaust gas flow path 12 allows the exhaust gas EG, which has undergone heat exchange in the waste heat recovery boiler 11 of the waste treatment system 200, to circulate inside. The exhaust gas flow path 12 is connected to the exhaust gas outlet of the waste heat recovery boiler 11. Hereinafter, the direction in which the exhaust gas EG flows within the exhaust gas flow path 12 will simply be referred to as the "flow direction of the exhaust gas EG". Furthermore, within the flow direction of the exhaust gas EG, the side facing the exhaust gas outlet of the waste heat recovery boiler 11 will be referred to as the "upstream side", and the opposite side will be referred to as the "downstream side".

[0020] (First heat recovery unit) The first heat recovery unit 13 is a device (heat exchanger) that exchanges heat between the exhaust gas EG flowing through the exhaust gas passage 12 and a heat transfer medium introduced from the outside. In other words, the first heat recovery unit 13 adjusts the temperature of the exhaust gas EG flowing through the exhaust gas passage 12. In this embodiment, the first heat recovery unit 13 is an economizer. The first heat recovery unit 13 is located in the exhaust gas passage 12. Here, "in the exhaust gas passage 12" means in the middle of the exhaust gas passage 12, not inside the exhaust gas passage 12. Exhaust gas EG flowing out from the waste heat recovery boiler 11 flows into the first heat recovery unit 13 through the exhaust gas passage 12. In other words, the exhaust gas EG that flows into the first heat recovery unit 13 is cooled by heat exchange with a heat transfer medium supplied from the outside.

[0021] On the other hand, the heat transfer medium introduced into the first heat recovery unit 13 from an external source is heated by the exhaust gas EG. In this embodiment, the heat transfer medium supplied to the first heat recovery unit 13 from an external source is, for example, water (feedwater to the waste heat recovery boiler 11). The exhaust gas EG, having completed heat exchange in the first heat recovery unit 13, flows out into the exhaust gas flow path 12 downstream of the first heat recovery unit 13. The heat transfer medium heated in the first heat recovery unit 13 is used as a heat source in an external device.

[0022] (Dust collection equipment) In this embodiment, the dust collection equipment 14 is a catalyst-supported bag filter that removes soot and dust (dust removal), nitrogen oxides (denitrification), and harmful substances such as dioxins contained in the exhaust gas EG passing through the exhaust gas passage 12. The dust collection equipment 14 is located downstream of the first heat recovery unit 13 in the exhaust gas passage 12. Therefore, the exhaust gas EG flowing out of the first heat recovery unit 13 flows into the dust collection equipment 14 through the exhaust gas passage 12.

[0023] In this embodiment, the dust collection equipment 14 includes a dust collection equipment body 141 and a denitrification layer 142. Exhaust gas EG from the first heat recovery unit 13 flows into the dust collection equipment body 141 through the exhaust gas flow path 12. The denitrification layer 142 is a filter cloth located inside the dust collection equipment body 141. A denitrification catalyst capable of denitrifying the exhaust gas EG is supported on the denitrification layer 142. The exhaust gas EG that flows into the dust collection equipment body 141 passes through the denitrification layer 142 and is denitrified by the denitrification catalyst supported on the denitrification layer 142. The exhaust gas EG that has passed through the dust collection equipment 14 flows out into the exhaust gas flow path 12 downstream of the dust collection equipment 14.

[0024] (Second heat recovery unit) The second heat recovery unit 15 is a device (heat exchanger) that recovers heat from the exhaust gas EG flowing through the exhaust gas passage 12 by exchanging heat with a heat transfer medium introduced from the outside. In other words, the second heat recovery unit 15 adjusts the temperature of the exhaust gas EG flowing through the exhaust gas passage 12. In this embodiment, the second heat recovery unit 15 is an economizer. The second heat recovery unit 15 recovers heat from exhaust gas EG that is at a lower temperature than the exhaust gas EG flowing into the first heat recovery unit 13.

[0025] The second heat recovery unit 15 is located downstream of the dust collection equipment 14 in the exhaust gas flow path 12. Therefore, exhaust gas EG from the dust collection equipment 14 flows into the second heat recovery unit 15 through the exhaust gas flow path 12. The exhaust gas EG that flows into the second heat recovery unit 15 is cooled by heat exchange with a heat transfer medium supplied from the outside. On the other hand, the heat transfer medium introduced into the second heat recovery unit 15 is heated by the exhaust gas EG. In this embodiment, the heat transfer medium supplied from the outside to the second heat recovery unit 15 is, for example, water (feedwater to the waste heat recovery boiler 11). The exhaust gas EG that has completed heat exchange in the second heat recovery unit 15 flows out into the exhaust gas flow path 12 downstream of the second heat recovery unit 15. The heat transfer medium heated in the second heat recovery unit 15 is used as a heat source in an external device.

[0026] (Carbon dioxide capture device) The carbon dioxide recovery device 16 recovers carbon dioxide from the exhaust gas EG flowing through the exhaust gas passage 12. In this embodiment, the carbon dioxide recovery device 16 recovers carbon dioxide by a wet chemical absorption method. The exhaust gas EG flowing out from the second heat recovery unit 15 flows into the carbon dioxide recovery device 16 through the exhaust gas passage 12. The carbon dioxide recovery device 16 is connected to the waste heat recovery boiler 11 by the exhaust gas passage 12. In this embodiment, the carbon dioxide recovery device 16 includes a cooling tower 161, an absorption tower 162, and a regeneration tower 163.

[0027] The cooling tower 161 is a device for cooling the exhaust gas EG from the second heat recovery unit 15. Although detailed illustrations are omitted, the cooling tower 161 in this embodiment is equipped with a circulation line for circulating the cooling tower circulating water, a pump, and a heat exchanger that cools the cooling tower circulating water by exchanging heat with cooling water introduced from the outside. The exhaust gas EG is cooled by bringing the cooling tower circulating water, which has been cooled by the cooling water, into contact with the exhaust gas EG. In other words, the exhaust gas EG that flows into the cooling tower 161 is cooled by exchanging heat with the cooling tower circulating water. The exhaust gas EG cooled in the cooling tower 161 is then led to the absorption tower 162.

[0028] The absorption tower 162 is a device that removes carbon dioxide from exhaust gas EG introduced into the carbon dioxide recovery device 16 using an absorbent liquid (amine absorbent liquid). Exhaust gas EG from the cooling tower 161 is introduced into the absorption tower 162. Inside the absorption tower 162, the absorbent liquid is sprayed from the top downwards. The absorbent liquid sprayed inside the cooling tower 161 absorbs carbon dioxide from the exhaust gas EG by coming into contact with it. The exhaust gas EG from which carbon dioxide has been removed inside the absorption tower 162 is sent to the chimney 17 through the outlet passage 18 connected to the absorption tower 162. The exhaust gas EG sent to the chimney 17 is discharged into the atmosphere. Meanwhile, the absorbent liquid that has absorbed carbon dioxide is led to the regeneration tower 163.

[0029] The regeneration tower 163 is a device that heats the absorbent liquid from the absorption tower 162 and separates carbon dioxide from the absorbent liquid. The regeneration tower 163 regenerates the absorbent liquid by separating carbon dioxide from it. In this embodiment, the regeneration tower 163 has a regeneration tower body 163a and a reboiler 163b. The regeneration tower body 163a has a packed bed and trays inside. The absorbent liquid that has absorbed carbon dioxide from the absorption tower 162 is introduced into the space inside the regeneration tower body 163a via an absorbent liquid supply pipe.

[0030] The reboiler 163b is connected, for example, to the lower part of the regeneration tower body 163a by piping. A heat transfer medium for heating the absorbent liquid is introduced to the reboiler 163b from the outside. In this embodiment, the heat transfer medium supplied to the reboiler 163b from the outside is, for example, steam (main steam). The absorbent liquid that flows into the regeneration tower body 163a is heated by heat exchange with the heat transfer medium. As the absorbent liquid is heated inside the regeneration tower body 163a, carbon dioxide is separated from the absorbent liquid. The carbon dioxide separated from the absorbent liquid is led to the outside of the carbon dioxide recovery device 16. The absorbent liquid from which carbon dioxide has been separated is led back to the absorption tower 162. The steam, which is used as a heat transfer medium and cooled by heating the absorbent liquid, becomes condensed water. This condensed water is led to, for example, the power generation system 300.

[0031] (Reducing agent supply unit) The reducing agent supply unit 19 supplies the reducing agent to the exhaust gas EG flowing upstream of the dust collection equipment 14 in the flow direction of the exhaust gas EG. In other words, the reducing agent supply unit 19 adds the reducing agent to the exhaust gas EG. The reducing agent supply unit 19 supplies the reducing agent to the exhaust gas EG flowing through the incinerator 10 and the waste heat recovery boiler 11 of the waste treatment system 200. In this embodiment, the reducing agent supply unit 19 supplies the reducing agent to the exhaust gas EG flowing through the waste heat recovery boiler 11. The reducing agent removes nitrogen oxides from the exhaust gas EG by reducing the nitrogen oxides in the exhaust gas EG. In this embodiment, for example, ammonia (NH3) is used as the reducing agent. The reducing agent supply unit 19 has a reducing agent supply source 191 and a reducing agent supply line 192.

[0032] In this embodiment, the reducing agent supply source 191 is a tank that stores a reducing agent in liquid form. The reducing agent supply line 192 guides the reducing agent stored in the reducing agent supply source 191 into the waste heat recovery boiler 11. Therefore, the reducing agent supply line 192 connects the reducing agent supply source 191 and the waste heat recovery boiler 11. The reducing agent sent to the waste heat recovery boiler 11 through the reducing agent supply line 192 is sprayed into the exhaust gas EG flowing inside the waste heat recovery boiler 11. The reducing agent supply line 192 is equipped with, for example, a pump (not shown) for sending the reducing agent from the reducing agent supply source 191 to the waste heat recovery boiler 11.

[0033] (Activated carbon supply section) The activated carbon supply unit 20 supplies a reducing agent to the exhaust gas EG flowing upstream of the dust collection equipment 14 in the flow direction of the exhaust gas EG. In this embodiment, the activated carbon supply unit 20 supplies activated carbon to the exhaust gas EG flowing downstream of the first heat recovery unit 13 in the exhaust gas flow path 12. The activated carbon adsorbs mercury contained in the exhaust gas EG. Therefore, by supplying activated carbon to the exhaust gas EG flowing in the exhaust gas flow path 12, mercury contained in the exhaust gas EG is removed. The activated carbon supply unit 20 has an activated carbon supply source 201 and an activated carbon supply line 202.

[0034] In this embodiment, the activated carbon supply source 201 is a tank that holds powdered or granular activated carbon inside. The activated carbon supply line 202 guides the activated carbon held in the activated carbon supply source 201 into the exhaust gas flow path 12 downstream of the first heat recovery unit 13. Therefore, the activated carbon supply line 202 connects the activated carbon supply source 201 to the exhaust gas flow path 12 downstream of the first heat recovery unit 13. The activated carbon sent to the exhaust gas flow path 12 through the activated carbon supply line 202 is scattered into the exhaust gas EG flowing through the exhaust gas flow path 12. The activated carbon supply line 202 is equipped with, for example, a blower (not shown) for sending activated carbon from the reducing agent supply source 191 to the exhaust gas flow path 12.

[0035] (Alkaline powder supply unit) The alkaline powder supply unit 21 supplies alkaline powder to the exhaust gas EG flowing upstream of the dust collection equipment 14 in the flow direction of the exhaust gas EG. In this embodiment, the alkaline powder is, for example, slaked lime (Ca(OH)2). In this embodiment, the alkaline powder supply unit 21 supplies alkaline powder to the exhaust gas EG flowing downstream of the first heat recovery unit 13 in the exhaust gas flow path 12. If the alkaline powder supplied to the exhaust gas EG is, for example, slaked lime, this slaked lime contains sulfur oxides (SO2) contained in the exhaust gas EG. X It reacts with ) to become calcium sulfate (CaSO4). Also, if the alkaline powder supplied to the exhaust gas EG is, for example, slaked lime, this slaked lime reacts with hydrogen chloride (HCl) contained in the exhaust gas EG to become calcium chloride (CaCl2). The alkaline powder supply unit 21 has an alkaline powder supply source 211 and an alkaline powder supply line 212.

[0036] In this embodiment, the alkaline powder supply source 211 is a tank that holds powdered or granular alkaline powder inside. The alkaline powder supply line 212 guides the alkaline powder held in the alkaline powder supply source 211 into the exhaust gas flow path 12 upstream of the first heat recovery unit 13. Therefore, the alkaline powder supply line 212 connects the alkaline powder supply source 211 to the exhaust gas flow path 12 downstream of the first heat recovery unit 13. More specifically, the alkaline powder supply line 212 is connected to the exhaust gas flow path 12 downstream of the portion to which the activated carbon supply line 202 is connected. The alkaline powder sent to the exhaust gas flow path 12 through the alkaline powder supply line 212 is scattered into the exhaust gas EG flowing through the exhaust gas flow path 12. Furthermore, the alkaline powder supply line 212 is equipped with, for example, a blower (not shown) for sending the alkaline powder from the alkaline powder supply source 211 to the exhaust gas flow path 12.

[0037] (Alkaline agent supply unit) The alkaline agent supply unit 22 supplies an alkaline agent into the carbon dioxide recovery device 16. In this embodiment, the alkaline agent supply unit 22 supplies an alkaline agent to the cooling tower circulating water in the cooling tower 161 of the carbon dioxide recovery device 16. In other words, the alkaline agent supply unit 22 adds an alkaline agent to the cooling tower circulating water. In this embodiment, for example, an aqueous sodium hydroxide solution is used as the alkaline agent. Therefore, when the alkaline agent supplied to the cooling tower circulating water is an aqueous sodium hydroxide solution, this aqueous sodium hydroxide solution reacts with sulfur oxides contained in the exhaust gas EG to become sodium sulfate, and reacts with hydrogen chloride contained in the exhaust gas EG to become sodium chloride. By supplying an alkaline agent to the cooling tower circulating water circulating in the cooling tower 161, the exhaust gas EG is desulfurized and desalinated. The alkaline agent supply unit 22 has an alkaline agent supply source 221 and an alkaline agent supply line 222.

[0038] In this embodiment, the alkaline agent supply source 221 is a tank that holds an alkaline agent, such as an aqueous sodium hydroxide solution, inside. The alkaline agent supply line 222 guides the alkaline agent held in the alkaline agent supply source 221 into the cooling tower 161. Therefore, the alkaline agent supply line 222 connects the alkaline agent supply source 221 and the cooling tower 161. The alkaline agent sent to the cooling tower 161 through the alkaline agent supply line 222 is sprayed onto the cooling tower circulating water that circulates within the cooling tower 161. The alkaline agent supply line 222 is equipped with, for example, a pump (not shown) for sending the alkaline agent from the alkaline agent supply source 221 to the cooling tower 161.

[0039] (Power generation system) The power generation system 300 is a system that generates electricity using the heat from the exhaust gas EG generated in the waste treatment system 200. The power generation system 300 includes a steam turbine 31, a condenser 32, a deaerator 34, a first feedwater pump 33a, a second feedwater pump 33b, a main steam line 30a, a first connection line 30c, a second connection line 30d, a third connection line 30e, a boiler feedwater line 30b, a first feedwater bypass line 30g, a first heat transfer valve 15a, a second feedwater bypass line 30h, and a second heat transfer valve 13a.

[0040] (Steam turbine) The steam turbine 31 is a rotating machine driven by steam from the heat recovery boiler 11, which rotates a generator GEN connected to the steam turbine 31. In this embodiment, steam generated in the heat recovery boiler 11 is introduced into the steam turbine 31 through the main steam line 30a. The main steam line 30a connects the steam outlet of the heat recovery boiler 11 to the steam inlet of the steam turbine 31.

[0041] Furthermore, although not shown in Figure 1, the steam from the waste heat recovery boiler 11 flowing through the main steam line 30a is led to, for example, the reboiler 163b. The steam introduced into the reboiler 163b is used as a heat transfer medium to heat the absorbent liquid within the regeneration tower body 163a. ​​In other words, a portion of the steam from the waste heat recovery boiler 11 can be used as a heat source in the reboiler 163b of the carbon dioxide recovery device 16.

[0042] (Condenser) The condenser 32 is connected to the steam turbine 31. Steam that has finished its expansion work in the steam turbine 31 is led into the condenser 32, where it is cooled and condensed into water (condensate), which is stored in the condenser 32. The water stored in the condenser 32 is led to the second heat recovery unit 15 via the first connection line 30c to be used as a heat transfer medium for heat exchange with the exhaust gas EG in the second heat recovery unit 15.

[0043] Here, the first connection line 30c connects the condenser 32 and the second heat recovery unit 15. A first feedwater pump 33a is located in the first connection line 30c. When driven, the first feedwater pump 33a sends water from the condenser 32 to the second heat recovery unit 15. In this embodiment, the rotational speed of the first feedwater pump 33a (the flow rate of water pumped from the condenser 32 to the second heat recovery unit 15) is controlled by the control device 500. Specifically, the first feedwater pump 33a receives a signal indicating the rotational speed from the control device 500 via wired or wireless communication. The first feedwater pump 33a rotates based on the rotational speed indicated by the signal and pumps the water in the first connection line 30c to the second heat recovery unit 15.

[0044] In other words, the first water supply pump 33a can adjust the flow rate of water flowing through the first connection line 30c by being controlled by the control device 500. By adjusting the rotation speed of the first water supply pump 33a, the flow rate of water used as a heat transfer medium flowing into the second heat recovery unit 15 is adjusted.

[0045] The water introduced into the second heat recovery unit 15 through the first connection line 30c exchanges heat with the exhaust gas EG within the second heat recovery unit 15 and is heated by the exhaust gas EG. The water heated within the second heat recovery unit 15 is then led to the deaerator 34 through the second connection line 30d.

[0046] The first water supply bypass line 30g has one end connected to the first connection line 30c and the other end connected to the second connection line 30d. Therefore, some of the water flowing through the first connection line 30c can flow into the first water supply bypass line 30g from one end and into the second connection line 30d through the other end. Thus, the first water supply bypass line 30g can bypass water from the first connection line 30c to the second connection line 30d without passing through the second heat recovery unit 15.

[0047] A first heat transfer valve 15a is located in the first water supply bypass line 30g. The first heat transfer valve 15a is a flow control valve capable of adjusting the flow rate of water flowing through the first water supply bypass line 30g. The first heat transfer valve 15a adjusts the flow rate of water flowing through the first water supply bypass line 30g by controlling its opening degree. In this embodiment, the opening degree of the first heat transfer valve 15a is controlled by a control device 500. Specifically, the first heat transfer valve 15a receives a signal indicating the opening degree from the control device 500 via wired or wireless communication, and adjusts its opening degree based on the received signal.

[0048] The first heat transfer valve 15a can be controlled by the control device 500 to adjust the flow rate of water flowing through the first water supply bypass line 30g. By adjusting the opening degree of the first heat transfer valve 15a, the flow rate of water used as a heat transfer medium flowing into the second heat recovery unit 15 is adjusted.

[0049] (Deaeration device) The deaerator 34 heats the water from the second heat recovery unit 15 and deaerates the dissolved gases (oxygen, carbon dioxide, etc.) contained in the water. Although detailed illustrations are omitted, steam extracted from the steam turbine 31 (extracted steam) is introduced into the deaerator 34 as a heat source for heating (deaerating) the water. The water deaerated by the deaerator 34 is led to the first heat recovery unit 13 through the third connection line 30e. The third connection line 30e connects the water inlet outlet of the deaerator 34 to the first heat recovery unit. The water introduced into the first heat recovery unit 13 through the third connection line 30e is used as a heat transfer medium for heat exchange with the exhaust gas EG within the first heat recovery unit 13.

[0050] A second feedwater pump 33b is located in the third connection line 30e. When driven, the second feedwater pump 33b sends water from the deaerator 34 to the first heat recovery unit 13. In this embodiment, the rotational speed of the second feedwater pump 33b (the flow rate of water pumped from the deaerator 34 to the first heat recovery unit 13) is controlled by the control device 500. Specifically, the second feedwater pump 33b receives a signal indicating the rotational speed from the control device 500 via wired or wireless communication. The second feedwater pump 33b rotates based on the rotational speed indicated by the signal and pumps the water in the third connection line 30e to the first heat recovery unit 13.

[0051] In other words, the second water supply pump 33b can adjust the flow rate of water flowing through the third connection line 30e by being controlled by the control device 500. By adjusting the rotation speed of the second water supply pump 33b, the flow rate of water used as a heat transfer medium flowing into the first heat recovery unit 13 is adjusted.

[0052] The water that has completed heat exchange in the first heat recovery unit 13 is led to the waste heat recovery boiler 11 via the boiler feedwater line 30b. The boiler feedwater line 30b connects the first heat recovery unit 13 to the feedwater inlet of the waste heat recovery boiler 11. The water introduced into the waste heat recovery boiler 11 via the boiler feedwater line 30b is used as a heat transfer medium for heat exchange with the exhaust gas EG within the waste heat recovery boiler 11.

[0053] Water introduced into the heat recovery boiler 11 via the boiler feedwater line 30b exchanges heat with the exhaust gas EG within the heat recovery boiler 11 and is heated by the exhaust gas EG to become steam (main steam). This steam is then led to the steam turbine 31 via the main steam line 30a.

[0054] The second feedwater bypass line 30h has one end connected to the third connection line 30e and the other end connected to the boiler feedwater line 30b. Therefore, some of the water flowing through the third connection line 30e can flow into the second feedwater bypass line 30h from one end and into the boiler feedwater line 30b through the other end. Thus, the second feedwater bypass line 30h can bypass water from the third connection line 30e to the boiler feedwater line 30b without passing through the first heat recovery unit 13.

[0055] A second heat transfer valve 13a is located in the second water supply bypass line 30h. The second heat transfer valve 13a is a flow control valve capable of adjusting the flow rate of water flowing through the second water supply bypass line 30h. The flow rate of water flowing through the second water supply bypass line 30h is adjusted by controlling the opening degree of the second heat transfer valve 13a. In this embodiment, the opening degree of the second heat transfer valve 13a is controlled by the control device 500. Specifically, the second heat transfer valve 13a receives a signal indicating the opening degree from the control device 500 via wired or wireless communication, and adjusts the opening degree based on the received signal.

[0056] The second heat transfer valve 13a can be controlled by the control device 500 to adjust the flow rate of water flowing through the second water supply bypass line 30h. By adjusting the opening degree of the second heat transfer valve 13a, the flow rate of water used as a heat transfer medium flowing into the first heat recovery unit 13 is adjusted.

[0057] Here, we will explain the temperature change of the exhaust gas EG flowing through the exhaust gas flow path 12 in the exhaust gas treatment system 100. As shown in Figure 2, the exhaust gas EG that flows from the waste heat recovery boiler 11 into the exhaust gas flow path 12 flows into the first heat recovery unit 13. The exhaust gas EG that flows into the first heat recovery unit 13 is cooled by heat exchange with water. The temperature of the exhaust gas EG after heat exchange in the first heat recovery unit 13 is, for example, 150 to 230°C. The exhaust gas EG that flows out of the first heat recovery unit 13 passes through the dust collection equipment 14 and then flows into the second heat recovery unit 15. The exhaust gas EG that flows into the second heat recovery unit 15 is cooled by heat exchange with water. The temperature of the exhaust gas EG that has finished heat exchange in the second heat recovery unit 15 is, for example, 70 to 150°C. The exhaust gas EG that flows out of the second heat recovery unit 15 flows into the carbon dioxide recovery device 16. The exhaust gas EG that flows into the carbon dioxide recovery device 16 is cooled in the cooling tower 161. The temperature of the exhaust gas EG after cooling in the cooling tower 161 is, for example, 20 to 60°C. Therefore, the exhaust gas EG is supplied from the dust collection equipment 14 to the carbon dioxide recovery device 16 via the second heat recovery unit 15 while maintaining a temperature below the outlet gas temperature of the dust collection equipment 14. Here, "outlet gas temperature" refers to the temperature of the exhaust gas EG before it flows out of the dust collection equipment 14 and into the second heat recovery unit 15.

[0058] (sensor) The sensor 400 is installed in the power generation equipment 1000. In this embodiment, the sensor 400 includes a first thermometer 41, a second thermometer 42, a third thermometer 43, a nitrogen oxide concentration detection unit 44, and a sulfur oxide concentration detection unit 45.

[0059] (1st thermometer) The first thermometer 41 is positioned between the first heat recovery unit 13 and the dust collection equipment 14 in the exhaust gas flow path 12. In this embodiment, the first thermometer 41 is positioned downstream of the connection point with the alkaline powder supply line 212 in the exhaust gas flow path 12. The first thermometer 41 detects the temperature of the exhaust gas EG flowing into the dust collection equipment 14. The first thermometer 41 detects the temperature of the exhaust gas EG at predetermined time intervals and transmits a signal indicating the detection result to the control device 500 via wired or wireless communication. Hereinafter, for convenience of explanation, the temperature of the exhaust gas EG detected by the first thermometer 41 will be referred to as "first temperature T1".

[0060] (Second thermometer) The second thermometer 42 is positioned between the dust collection equipment 14 and the second heat recovery unit 15 in the exhaust gas flow path 12. In this embodiment, the second thermometer 42 detects the temperature of the exhaust gas EG flowing out from the dust collection equipment 14. In other words, the second thermometer 42 detects the temperature of the exhaust gas EG flowing into the second heat recovery unit 15. The second thermometer 42 detects the temperature of the exhaust gas EG at predetermined time intervals and transmits a signal indicating the detection result to the control device 500 via wired or wireless communication. For the sake of explanation, the temperature of the exhaust gas EG detected by the second thermometer 42 will be referred to as "second temperature T2". That is, second temperature T2 is the outlet gas temperature described above.

[0061] (3rd thermometer) The third thermometer 43 is positioned between the second heat recovery unit 15 and the carbon dioxide recovery device 16 in the exhaust gas flow path 12. In this embodiment, the third thermometer 43 detects the temperature of the exhaust gas EG flowing in from the second heat recovery unit 15. In other words, the third thermometer 43 detects the temperature of the exhaust gas EG flowing into the cooling tower 161 of the carbon dioxide recovery device 16. The third thermometer 43 detects the temperature of the exhaust gas EG at predetermined time intervals and transmits a signal indicating the detection result to the control device 500 via wired or wireless communication. Hereinafter, for the sake of convenience, the temperature of the exhaust gas EG detected by the third thermometer 43 will be referred to as "third temperature T3".

[0062] (Nitrogen oxide concentration detection unit) The nitrogen oxide concentration detection unit 44 is equipped with a nitrogen oxide sensor (NO) capable of detecting the nitrogen oxide concentration A1 of the exhaust gas EG. X This is a sensor. In this embodiment, the nitrogen oxide concentration detection unit 44 is located between the dust collection equipment 14 and the second heat recovery unit 15 in the exhaust gas flow path 12. Therefore, the nitrogen oxide concentration detection unit 44 detects the nitrogen oxide concentration A1 of the exhaust gas EG flowing out from the dust collection equipment 14. In other words, the nitrogen oxide concentration detection unit 44 detects the concentration of nitrogen oxides contained in the exhaust gas EG flowing into the second heat recovery unit 15. The nitrogen oxide concentration detection unit 44 detects the nitrogen oxide concentration A1 of the exhaust gas EG at predetermined time intervals and transmits a signal indicating the detection result to the control device 500 via wired or wireless communication.

[0063] (Sulfur oxide concentration detection unit) The sulfur oxide concentration detection unit 45 is equipped with a sulfur oxide sensor (SO4) capable of detecting the sulfur oxide concentration A2 of the exhaust gas EG. X This is a sensor. In this embodiment, the sulfur oxide concentration detection unit 45 is located between the dust collection equipment 14 and the second heat recovery unit 15 in the exhaust gas flow path 12. Therefore, the sulfur oxide concentration detection unit 45 detects the sulfur oxide concentration A2 of the exhaust gas EG flowing out from the dust collection equipment 14. In other words, the sulfur oxide concentration detection unit 45 detects the concentration of sulfur oxides contained in the exhaust gas EG flowing into the second heat recovery unit 15. The sulfur oxide concentration detection unit 45 detects the sulfur oxide concentration A2 of the exhaust gas EG at predetermined time intervals and transmits a signal indicating the detection result to the control device 500 via wired or wireless communication.

[0064] (Control device) The control device 500 receives signals indicating the detection results from the sensor 400 described above, and controls the amount of heat transfer medium supplied to the first heat recovery unit 13 and the amount of heat transfer medium supplied to the second heat recovery unit 15. As shown in Figure 3, the control device 500 in this embodiment includes a detection unit 51, a determination unit 52, a setting unit 53, a control unit 54, and a storage unit 55. The storage unit 55 stores information used by the determination unit 52 for determination processing.

[0065] (Detection unit) The detection unit 51 receives a signal from the sensor 400 and obtains the detection result of the sensor 400.

[0066] The detection unit 51 receives a signal transmitted from the first thermometer 41 and obtains the first temperature T1 indicated by the signal. The detection unit 51 sends the obtained first temperature T1 to the determination unit 52. The detection unit 51 also receives a signal transmitted from the second thermometer 42 and obtains the second temperature T2 indicated by the signal. The detection unit 51 sends the obtained second temperature T2 to the determination unit 52. The detection unit 51 also receives a signal transmitted from the third thermometer 43 and obtains the third temperature T3 indicated by the signal. The detection unit 51 sends the obtained third temperature T3 to the determination unit 52.

[0067] Furthermore, the detection unit 51 receives a signal transmitted from the nitrogen oxide concentration detection unit 44 and obtains the nitrogen oxide concentration A1 indicated by the signal. The detection unit 51 sends the obtained nitrogen oxide concentration A1 to the setting unit 53. Also, the detection unit 51 receives a signal transmitted from the sulfur oxide concentration detection unit 45 and obtains the sulfur oxide concentration A2 indicated by the signal. The detection unit 51 sends the obtained sulfur oxide concentration A2 to the determination unit 52.

[0068] (Judgment Department) The determination unit 52 performs a determination process based on the detection result of the sensor 400 received from the detection unit 51. When the determination unit 52 receives a first temperature T1 and a second temperature T2 from the detection unit 51, it compares the first temperature T1 and the second temperature T2 with a predetermined gas temperature threshold Tx. In this embodiment, the gas temperature threshold Tx is, for example, a temperature preset by the setting unit 53. The gas temperature threshold Tx is, for example, a value in the temperature range of 150 to 230°C. Preferably, it is 180 to 220°C.

[0069] The determination unit 52 determines that "adjustment of the first temperature T1 is necessary" if the first temperature T1 deviates from the gas temperature threshold Tx. Here, "the first temperature T1 deviates from the gas temperature threshold Tx" means that the first temperature T1 is, for example, outside the temperature range indicated by the gas temperature threshold Tx. Conversely, "the first temperature T1 does not deviate from the gas temperature threshold Tx" means that the first temperature T1 is, for example, within the temperature range indicated by the gas temperature threshold Tx.

[0070] Furthermore, the determination unit 52 determines that "the first temperature T1 is high" if the first temperature T1 is greater than the upper limit of the temperature range indicated by the gas temperature threshold Tx. Also, the determination unit 52 determines that "the first temperature T1 is low" if the first temperature T1 is less than the lower limit of the temperature range indicated by the gas temperature threshold Tx.

[0071] Furthermore, the determination unit 52 determines that "adjustment of the second temperature T2 is necessary" if the second temperature T2 deviates from the gas temperature threshold Tx. Here, "the second temperature T2 deviates from the gas temperature threshold Tx" means that the second temperature T2 is, for example, outside the temperature range indicated by the gas temperature threshold Tx. Conversely, "the second temperature T2 does not deviate from the gas temperature threshold Tx" means that the second temperature T2 is, for example, within the temperature range indicated by the gas temperature threshold Tx.

[0072] Furthermore, the determination unit 52 determines that "the second temperature T2 is high" if the second temperature T2 is greater than the upper limit of the temperature range indicated by the gas temperature threshold Tx. Also, the determination unit 52 determines that "the second temperature T2 is low" if the second temperature T2 is less than the lower limit of the temperature range indicated by the gas temperature threshold Tx.

[0073] On the other hand, the determination unit 52 determines that "adjustment of the first temperature T1 is not necessary" if the first temperature T1 does not deviate from the gas temperature threshold Tx. Also, the determination unit 52 determines that "adjustment of the second temperature T2 is not necessary" if the second temperature T2 does not deviate from the gas temperature threshold Tx. The gas temperature threshold Tx is stored, for example, in the storage unit 55.

[0074] Furthermore, when the determination unit 52 receives a third temperature T3 from the detection unit 51, it compares the third temperature T3 with a predetermined gas temperature threshold Ty. In this embodiment, the gas temperature threshold Ty is, for example, a temperature range that is set in advance according to the power generation equipment 1000.

[0075] The determination unit 52 determines that "adjustment of the third temperature T3 is necessary" if the third temperature T3 deviates from the gas temperature threshold Ty. Here, "the third temperature T3 deviates from the gas temperature threshold Ty" means that the third temperature T3 is, for example, outside the temperature range indicated by the gas temperature threshold Ty. Conversely, "the third temperature T3 does not deviate from the gas temperature threshold Ty" means that the third temperature T3 is, for example, within the temperature range indicated by the gas temperature threshold Ty.

[0076] Furthermore, the determination unit 52 determines that "the third temperature T3 is high" if the third temperature T3 is greater than the upper limit of the temperature range indicated by the gas temperature threshold Ty. Also, the determination unit 52 determines that "the third temperature T3 is low" if the third temperature T3 is less than the lower limit of the temperature range indicated by the gas temperature threshold Ty.

[0077] On the other hand, the determination unit 52 determines that "adjustment of the third temperature T3 is not necessary" if the third temperature T3 does not deviate from the gas temperature threshold Ty. The gas temperature threshold Ty is stored in advance, for example, by the storage unit 55.

[0078] (Settings section) The setting unit 53 sets the gas temperature threshold Tx based on the detection result of the sensor 400 received from the detection unit 51. When the setting unit 53 receives nitrogen oxide concentration A1 and sulfur oxide concentration A2 from the detection unit 51, it refers to predetermined correspondence information associated with these and the gas temperature threshold Tx to be set, and obtains a gas temperature threshold Tx corresponding to one or more of the nitrogen oxide concentration A1 and sulfur oxide concentration A2.

[0079] The setting unit 53 stores the acquired gas temperature threshold Tx in the storage unit 55. In this embodiment, the correspondence information is, for example, a table that associates one or more of the nitrogen oxide concentration A1 and sulfur oxide concentration A2 with the gas temperature threshold Tx. The correspondence information may also be a function that takes one or more of the nitrogen oxide concentration A1 and sulfur oxide concentration A2 as arguments and returns the gas temperature threshold Tx as the return value. The correspondence information is stored in advance by the storage unit 55, for example.

[0080] (Control Unit) The control unit 54 controls the amount of heat transfer medium supplied to the first heat recovery unit 13 and the amount of heat transfer medium supplied to the second heat recovery unit 15 based on the determination result from the determination unit 52.

[0081] The control unit 54 controls the amount of heat transfer medium supplied to the first heat recovery unit 13 when the determination unit 52 determines that "adjustment of the first temperature T1 is necessary" or "adjustment of the second temperature T2 is necessary". Specifically, when the determination unit 52 determines that "the first temperature T1 is high" or "the second temperature T2 is high", the control unit 54 sends a signal to the second heat transfer medium valve 13a indicating an increase in opening degree. Also, when the determination unit 52 determines that "the first temperature T1 is low" or "the second temperature T2 is low", the control unit 54 sends a signal to the second heat transfer medium valve 13a indicating a decrease in opening degree. On the other hand, when the determination unit 52 determines that "adjustment of the first temperature T1 is not necessary" and "adjustment of the second temperature T2 is not necessary", the control unit 54 sends a signal to the second heat transfer medium valve 13a indicating that the opening degree is maintained. Through these operations by the control unit 54, the amount of heat transfer medium supplied to the first heat recovery unit 13 is controlled.

[0082] Furthermore, if the determination unit 52 determines that "adjustment of the third temperature T3 is necessary," the control unit 54 controls the amount of heat transfer medium supplied to the second heat recovery unit 15. Specifically, if the determination unit 52 determines that "the third temperature T3 is high," the control unit 54 sends a signal to the first heat transfer medium valve 15a indicating an increase in opening degree. Conversely, if the determination unit 52 determines that "the third temperature T3 is low," the control unit 54 sends a signal to the first heat transfer medium valve 15a indicating a decrease in opening degree. On the other hand, if the determination unit 52 determines that "adjustment of the third temperature T3 is not necessary," the control unit 54 sends a signal to the first heat transfer medium valve 15a indicating that the opening degree should be maintained. These actions by the control unit 54 control the amount of heat transfer medium supplied to the first heat recovery unit 13.

[0083] (Operation of the control device) Next, the operation of the control device 500 in this embodiment will be described.

[0084] The following describes an example of the operation of the control device 500, which controls the amount of heat transfer medium supplied to the first heat recovery unit 13, with reference to Figure 4. The detection unit 51 acquires the first temperature T1, the second temperature T2, the nitrogen oxide concentration A1, and the sulfur oxide concentration A2 (step S11). Next, the setting unit 53 sets the gas temperature threshold Tx based on one or more of the nitrogen oxide concentration A1 and sulfur oxide concentration A2 acquired by the detection unit 51 (step S12). Next, the determination unit 52 determines whether or not adjustment of the first temperature T1 or the second temperature T2 is necessary based on the acquired first temperature T1 and second temperature T2 (step S13). If the determination unit 52 determines that adjustment of the first temperature T1 or the second temperature T2 is necessary (step S13: YES), the control unit 54 controls the opening degree of the second heat transfer medium valve 13a (step S14). After the processing in step S14 is completed, the processing in step S11 is repeated. If the determination unit 52 determines that adjustment of the first temperature T1 is not necessary and adjustment of the second temperature T2 is not necessary (step S13: NO), the process in step S11 is repeated. The processes described above, from steps S11 to S14, are repeatedly performed during the operation phase of the exhaust gas treatment system 100.

[0085] The following describes an example of the operation of the control device 500, which controls the amount of heat transfer medium supplied to the second heat recovery unit 15, with reference to Figure 5. The detection unit 51 acquires the third temperature T3 (step S21). Next, the determination unit 52 determines whether or not adjustment of the third temperature T3 is necessary based on the acquired third temperature T3 (step S22). If the determination unit 52 determines that adjustment of the third temperature T3 is necessary (step S22: YES), the control unit 54 controls the opening degree of the first heat transfer medium valve 15a (step S23). After the processing in step S23 is completed, the processing in step S21 is repeated. If the determination unit 52 determines that adjustment of the third temperature T3 is not necessary (step S22: NO), the processing in step S21 is repeated. The processes described above, from steps S21 to S23, are repeatedly executed during the operation phase of the power generation equipment 1000.

[0086] (Exhaust gas treatment method) Next, the exhaust gas treatment method used in the power generation equipment 1000 will be described. This exhaust gas treatment method includes supplying the exhaust gas from the dust collection equipment 14 to the carbon dioxide recovery device 16 while maintaining a temperature below the outlet gas temperature of the dust collection equipment 14. The exhaust gas treatment method performs a heat exchange step.

[0087] In the heat exchange process, the control device 500 controls the amount of heat transfer medium flowing into the second heat recovery unit 15 based on the detection results of the sensor 400 located in the exhaust gas flow path 12. Specifically, the determination unit 52 of the control device 500 determines whether or not adjustment of the third temperature T3 is necessary based on the third temperature T3 obtained from the third thermometer 43 by the acquisition unit of the control device 500. The control unit 54 of the control device 500 controls the opening degree of the first heat transfer medium valve 15a based on the determination result of the determination unit 52. As a result, the temperature of the exhaust gas EG that has passed through the dust collection equipment 14 is cooled by heat exchange in the second heat recovery unit 15. Therefore, the exhaust gas EG is supplied to the carbon dioxide recovery device 16 while maintaining a temperature below the outlet gas temperature of the dust collection equipment 14.

[0088] (Effects and Benefits) According to the above exhaust gas treatment system configuration, the exhaust gas EG passing through the dust collection equipment 14 is denitrified by the denitrification layer 142 on which a denitrification catalyst is supported. The denitrified exhaust gas EG is supplied to the carbon dioxide recovery device 16 while maintaining an exhaust gas temperature below the temperature at which it was discharged from the dust collection equipment 14. In other words, since the exhaust gas EG is denitrified in the dust collection equipment 14, it does not need to be heated in the process from the dust collection equipment 14 to the carbon dioxide recovery device 16. Therefore, the thermal energy required for this heating can be reduced. In addition, if the exhaust gas treatment is insufficient, the amount of impurities such as sulfur oxides contained in the exhaust gas may increase. According to the above configuration, since sulfur oxides in the exhaust gas EG are removed in the denitrification layer 142 of the dust collection equipment 14 upstream of the carbon dioxide recovery device 16, it is possible to suppress the increase in the consumption of absorbent liquid from which impurities are absorbed in the carbon dioxide recovery device 16.

[0089] Furthermore, in the above configuration, a portion of the steam from the waste heat recovery boiler 11 flowing through the main steam line 30a can be used as a heat source in the reboiler 163b of the carbon dioxide recovery device 16. This makes it possible to suppress a decrease in the power generation efficiency of the power generation equipment 1000, even when the carbon dioxide recovery device 16 is introduced into the exhaust gas treatment system 100.

[0090] Furthermore, in the above configuration, the amount of heat transfer medium supplied to the first heat recovery unit 13, which is located upstream of the dust collection equipment 14 in the flow direction of the exhaust gas EG, is controlled based on a comparison of the detection results of one or more of the first thermometer 41 and the second thermometer 42 with the gas temperature threshold Tx. This stabilizes the temperature of the exhaust gas EG introduced into the dust collection equipment 14. Therefore, the denitrification performance of the exhaust gas EG in the dust collection equipment 14 can be stabilized. The inflow and accumulation of impurities into the absorbent liquid in the carbon dioxide recovery device 16 can be suppressed.

[0091] Furthermore, in the above configuration, the temperature of the exhaust gas EG passing through the dust collection equipment 14 is adjusted to a temperature corresponding to one or more of the nitrogen oxide concentration A1 and sulfur oxide concentration A2. Therefore, for example, when the nitrogen oxide concentration A1 and sulfur oxide concentration A2 are high, the temperature of the exhaust gas EG passing through the dust collection equipment 14 is controlled to increase, and when the nitrogen oxide concentration A1 and sulfur oxide concentration A2 are low, the temperature of the exhaust gas EG passing through the dust collection equipment 14 is controlled to decrease. As a result, the amount of power used in the exhaust gas treatment system 100 can be optimized.

[0092] Furthermore, according to the above configuration, the heat of the exhaust gas EG that has passed through the dust collection equipment 14 is recovered by the second heat recovery unit 15. At this time, the flow rate of the heat transfer medium supplied to the first heat recovery unit 13 is set to the exhaust gas temperature corresponding to one or more of the nitrogen oxide concentration A1 and sulfur oxide concentration A2, and the flow rate of the heat transfer medium supplied to the second heat recovery unit 15 is set based on the third temperature T3. This makes it possible to further stabilize the temperature of the exhaust gas EG moving from the second heat recovery unit 15 to the carbon dioxide recovery device 16 within the exhaust gas flow path 12. Therefore, it is possible to improve the denitrification performance of the exhaust gas EG in the denitrification layer 142 of the dust collection equipment 14 while suppressing a decrease in power generation efficiency.

[0093] Furthermore, in the above configuration, the amount of heat transfer medium supplied to the second heat recovery unit 15 is controlled based on a comparison between the detection result of the third thermometer 43 and the gas temperature threshold Ty. This stabilizes the amount of heat recovered from the exhaust gas EG. It also stabilizes the temperature of the exhaust gas EG flowing into the carbon dioxide recovery unit 16.

[0094] Furthermore, in the above configuration, a reducing agent is supplied to the exhaust gas EG before it flows into the dust collection equipment 14. The reducing agent supplied to the exhaust gas EG directly reacts with nitrogen oxides in the exhaust gas EG to remove these nitrogen oxides. The reducing agent supplied to the exhaust gas EG also passes through the denitrification equipment together with the exhaust gas EG. At this time, the reducing agent comes into contact with the denitrification catalyst in the denitrification layer 142, and nitrogen oxides are removed by the catalytic action of the denitrification layer 142 of the dust collection equipment 14. In other words, the denitrification catalyst is regenerated by the action of the reducing agent on it. As a result of these actions, the decrease in the denitrification efficiency in the dust collection equipment 14 can be suppressed.

[0095] Furthermore, in the above configuration, activated carbon is supplied to the exhaust gas EG before it flows into the dust collection equipment 14. As a result, impurities such as mercury contained in the exhaust gas EG are adsorbed by the activated carbon. Therefore, the remaining impurities such as mercury in the exhaust gas EG passing through the dust collection equipment 14 are suppressed, and as a result, the inflow of impurities into the absorbent liquid in the carbon dioxide recovery device 16 can be suppressed. Therefore, the mixing of impurities into the carbon dioxide recovered by the carbon dioxide recovery device 16 and the deterioration of the absorbent liquid can be reduced.

[0096] Furthermore, in the above configuration, alkaline powder is supplied to the exhaust gas EG before it flows into the dust collection equipment 14. As a result, sulfur oxides contained in the exhaust gas EG react with slaked lime, which is an alkaline powder, to form calcium sulfate. Therefore, it is possible to suppress contact between sulfur oxides contained in the exhaust gas EG and the denitrification catalyst in the dust collection equipment 14. Consequently, poisoning of the denitrification catalyst can be suppressed. In addition, by removing sulfur oxides upstream of the carbon dioxide recovery device 16, it is possible to reduce the amount of alkaline agent supplied to the cooling tower 161 in the carbon dioxide recovery device 16.

[0097] Furthermore, in the above configuration, sulfur oxides and hydrogen chloride contained in the exhaust gas EG react with the alkaline agent supplied to the cooling tower circulating water by the alkaline agent supply unit 22 within the cooling tower 161 of the carbon dioxide recovery device 16. As a result, the exhaust gas EG in the cooling tower 161 is desulfurized and desalinated. Since the exhaust gas EG can be desulfurized and desalinated in the cooling tower 161, the amount of chemicals (alkaline powders such as slaked lime and sodium bicarbonate) sprayed upstream of the dust collection equipment 14, which is a catalyst-supported bag filter, can be reduced. As a result, the amount of solid waste discharged can be reduced. In addition, the reduction in the amount of chemicals sprayed reduces the differential pressure rise in the catalyst-supported bag filter, extending the backwash interval. As a result, the lifespan of the catalyst-supported bag filter can be extended.

[0098] <Second Embodiment> The following describes a power generation facility 1000 according to a second embodiment of this disclosure. The exhaust gas treatment system 100 and power generation system 300 described in the second embodiment differ in some configuration from the exhaust gas treatment system 100 and power generation system 300 described in the first embodiment. Components similar to those in the first embodiment are denoted by the same reference numerals and their detailed descriptions are omitted. The exhaust gas treatment system 100 in the second embodiment further includes a bypass line 23 and a flow regulator 24 compared to the exhaust gas treatment system 100 described in the first embodiment.

[0099] (Exhaust gas treatment system) As shown in Figure 6, the exhaust gas treatment system 100 in this embodiment includes an exhaust gas flow path 12, a first heat recovery unit 13, a dust collection system 14, a second heat recovery unit 15, a carbon dioxide recovery device 16, a reducing agent supply unit 19, an activated carbon supply unit 20, an alkaline powder supply unit 21, an alkaline agent supply unit 22, a chimney 17, an outlet flow path 18, a bypass line 23, and a flow rate regulator 24.

[0100] (Bypass line) The bypass line 23 has one end 23a connected to the exhaust gas flow path 12 between the heat recovery boiler 11 and the first heat recovery unit 13, and the other end 23b connected to the exhaust gas flow path 12 between the first heat recovery unit 13 and the dust collection equipment 14. Therefore, a portion of the exhaust gas EG flowing through the exhaust gas flow path 12 can flow into the bypass line 23 from one end 23a and flow back into the exhaust gas flow path 12 through the other end 23b. In other words, the bypass line 23 can direct at least a portion of the exhaust gas EG flowing into the first heat recovery unit 13 to the exhaust gas EG flowing between the first heat recovery unit 13 and the dust collection equipment 14 without passing through the first heat recovery unit 13 (bypassing it). One end 23a of the bypass line 23 is located between the heat recovery boiler 11 and the first heat recovery unit 13 in the exhaust gas flow path 12. The other end 23b of the bypass line 23 is located on the first heat recovery unit 13 side, which is upstream of the connection point with the activated carbon supply line 202 in the exhaust gas flow path 12.

[0101] (Flow rate regulator) The flow regulator 24 is located in the bypass line 23. Here, "in the bypass line 23" means in the middle of the bypass line 23, not inside the bypass line 23. The flow regulator 24 is a flow control valve that can adjust the flow rate of exhaust gas EG flowing through the bypass line 23 by adjusting its opening degree. In this embodiment, the opening degree of the flow regulator 24 is controlled by the control device 500. Specifically, the flow control valve receives a signal indicating the opening degree from the control device 500 via wired or wireless communication. The flow control valve adjusts the flow rate of exhaust gas EG flowing through the bypass line 23 based on the opening degree indicated by the signal.

[0102] (Control device) As shown in Figure 7, the control device 500 in this embodiment includes a detection unit 51, a determination unit 52, a setting unit 53, a control unit 54a, and a storage unit 55.

[0103] The control unit 54a controls the opening of the flow regulator 24 when the determination unit 52 determines that "adjustment of the first temperature T1 is necessary" or "adjustment of the second temperature T2 is necessary". Specifically, when the determination unit 52 determines that "the first temperature T1 is high" or "the second temperature T2 is high", the control unit 54a sends a signal to the flow regulator 24 indicating a decrease in the opening. Also, when the determination unit 52 determines that "the first temperature T1 is low" or "the second temperature T2 is low", the control unit 54a sends a signal to the flow regulator 24 indicating an increase in the opening. In other words, the flow rate of exhaust gas EG flowing through the bypass line 23 is adjusted, and at the same time, the flow rate of exhaust gas EG flowing into the first heat recovery unit 13 is controlled. On the other hand, when the determination unit 52 determines that "adjustment of the first temperature T1 is not necessary" and "adjustment of the second temperature T2 is not necessary", the control unit 54a sends a signal to the flow regulator 24 indicating that the opening is maintained. The operation of these control units 54a controls the amount of heat transfer medium introduced into the first heat recovery unit 13.

[0104] The following describes an example of the operation of the control device 500, which controls the amount of heat transfer medium supplied to the first heat recovery unit 13, with reference to Figure 8. The detection unit 51 acquires the first temperature T1, the second temperature T2, the nitrogen oxide concentration A1, and the sulfur oxide concentration A2 (step S31). Next, the setting unit 53 sets the gas temperature threshold Tx based on one or more of the nitrogen oxide concentration A1 and sulfur oxide concentration A2 acquired by the detection unit 51 (step S32). Next, the determination unit 52 determines whether or not adjustment of the first temperature T1 or the second temperature T2 is necessary based on the acquired first temperature T1 and second temperature T2 (step S33). If the determination unit 52 determines that adjustment of the first temperature T1 or the second temperature T2 is necessary (step S33: YES), the control unit 54a controls the opening degree of the flow regulator 24 (step S34). After the processing in step S34 is completed, the processing in step S31 is repeated. If the determination unit 52 determines that adjustment of the first temperature T1 is not necessary and adjustment of the second temperature T2 is not necessary (step S33: NO), the process in step S31 is repeated. The processes described above, from steps S31 to S34, are repeatedly performed during the operation phase of the exhaust gas treatment system 100.

[0105] (Effects and Benefits) In the configuration of the second embodiment, the amount of exhaust gas EG supplied to the first heat recovery unit 13, which is located upstream of the dust collection equipment 14 in the flow direction of the exhaust gas EG, is controlled based on a comparison of the detection results of one or more of the first thermometer 41 and the second thermometer 42 with the gas temperature threshold Tx. This stabilizes the temperature of the exhaust gas EG introduced into the dust collection equipment 14. Therefore, the denitrification performance of the exhaust gas EG in the dust collection equipment 14 can be stabilized.

[0106] <Third Embodiment> The following describes a power generation equipment 1000 according to a third embodiment of this disclosure. The power generation equipment 1000 described in the third embodiment differs in some configuration from the power generation equipment 1000 of the first embodiment. Components similar to those in the first embodiment are denoted by the same reference numerals and their detailed descriptions are omitted. In the third embodiment, the carbon dioxide recovery device 16 in the exhaust gas treatment system 100 further includes a reclaimer 164 compared to the carbon dioxide recovery device 16 described in the first embodiment. The exhaust gas treatment system 100 in the third embodiment further includes a reducing agent introduction line 25 compared to the exhaust gas treatment system 100 described in the first embodiment.

[0107] (Exhaust gas treatment system) As shown in Figure 9, the exhaust gas treatment system 100 in this embodiment includes an exhaust gas flow path 12, a first heat recovery unit 13, a dust collection system 14, a second heat recovery unit 15, a carbon dioxide recovery device 16, a reducing agent supply unit 19, an activated carbon supply unit 20, an alkaline powder supply unit 21, an alkaline agent supply unit 22, a chimney 17, an outlet flow path 18, and a reducing agent introduction line 25.

[0108] (Carbon dioxide capture device) The carbon dioxide recovery device 16 in this embodiment includes a cooling tower 161, an absorption tower 162, a regeneration tower 163, and a reclaimer 164.

[0109] The reclaimer 164 is a device that receives a portion of the absorbent liquid from the regeneration tower 163, from which carbon dioxide is separated and led to the absorption tower 162, and separates it into a first liquid, from which impurities in the absorbent liquid are concentrated, and a second liquid, from which impurities have been separated. The first liquid is the wastewater discharged from the carbon dioxide recovery device 16. The first liquid contains amines. The reclaimer 164 is connected to a reducing agent introduction line 25 that leads to the waste heat recovery boiler 11. The first liquid separated by the reclaimer 164 is supplied into the furnace body 1 of the incinerator 10 through the reducing agent introduction line 25, and the second liquid is returned to the regeneration tower 163. Therefore, the reducing agent introduction line 25 connects the reclaimer 164 to the waste heat recovery boiler 11.

[0110] The first liquid, sent to the furnace body 1 through the reducing agent introduction line 25, is incinerated in the same way as the waste and other materials to be incinerated. The amines contained in the first liquid have a reducing effect, and by being incinerated simultaneously with the materials to be incinerated, the generation of nitrogen oxides is suppressed. In other words, the first liquid flowing through the reducing agent introduction line 25 functions as a reducing agent for nitrogen oxides, and the reducing agent introduction line 25 functions as a reducing agent supply unit 19 that supplies the reducing agent into the furnace body 1. The reducing agent introduction line 25 is equipped with, for example, a pump (not shown) for sending the reducing agent from the reclaimer 164 to the furnace body 1 of the incinerator 10.

[0111] (Effects and Benefits) According to the above configuration, a portion of the absorbent liquid flowing from the regeneration tower 163 to the absorption tower 162 is separated into a first liquid and a second liquid by the reclaimer 164, and the separated first liquid is added as a reducing agent to the exhaust gas EG in the waste heat recovery boiler 11. In other words, the first liquid, which is wastewater from the carbon dioxide recovery device 16, is used as a reducing agent. Therefore, the power and costs required to dispose of the first liquid as wastewater can be reduced. In addition, since the reducing agent introduction line 25 functions as a reducing agent supply unit 19, the amount of reducing agent handled by the reducing agent supply unit 19 can be reduced.

[0112] (Other embodiments) Although embodiments of this disclosure have been described in detail above with reference to the drawings, the specific configurations are not limited to those of each embodiment, and additions, omissions, substitutions, and other modifications to the configurations are possible without departing from the gist of this disclosure.

[0113] Figure 10 is a hardware configuration diagram showing the configuration of the computer 1100 according to this embodiment. The computer 1100 includes a processor 1110, main memory 1120, storage 1130, and interface 1140.

[0114] The control device 500 described above is implemented in the computer 1100. The operation of each processing unit described above is stored in the storage 1130 in the form of a program. The processor 1110 reads the program from the storage 1130, loads it into the main memory 1120, and executes the above processing according to the program. The processor 1110 also allocates a storage area in the main memory 1120 corresponding to the storage unit 55 described above, according to the program.

[0115] The program may be for the purpose of realizing some of the functions that the computer 1100 is to perform. For example, the program may perform functions in combination with other programs already stored in the storage 1130, or in combination with other programs implemented in other devices. In addition to the above configuration, the computer 1100 may also be equipped with a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device). Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, some or all of the functions realized by the processor 1110 may be realized by the integrated circuit.

[0116] Examples of storage 1130 include magnetic disks, magneto-optical disks, and semiconductor memory. Storage 1130 may be an internal medium directly connected to the bus of computer 1100, or an external medium connected to computer 1100 via interface 1140 or a communication line. Furthermore, if this program is distributed to computer 1100 via a communication line, computer 1100 that receives the distribution may expand the program into main memory 1120 and execute the above processing. In the above embodiment, storage 1130 is a tangible storage medium that is not temporary.

[0117] Furthermore, the program may be intended to implement some of the functions described above. Furthermore, the program may be a so-called differential file (differential program) that implements the aforementioned functions in combination with other programs already stored in the storage 1130.

[0118] Furthermore, although the first embodiment described a configuration in which the reducing agent supply unit 19 supplies the reducing agent to the exhaust gas EG flowing through the waste heat recovery boiler 11, the configuration is not limited to this. The reducing agent supply unit 19 may be configured to supply the reducing agent to the exhaust gas EG flowing upstream of the first heat recovery unit 13 in the exhaust gas flow path 12. In this case, the reducing agent supply line 192 only needs to connect the reducing agent supply source 191 to the portion of the exhaust gas flow path 12 upstream of the first heat recovery unit 13.

[0119] Furthermore, the gas temperature threshold Tx described in the first embodiment may be a temperature preset according to the power generation equipment 1000. In this case, the control device 500 does not need to have a setting unit 53.

[0120] Furthermore, the configurations of the power generation equipment 1000 described in each embodiment are not limited to independent configurations, and the power generation equipment may be configured by appropriately combining the components described in each embodiment.

[0121] Furthermore, the carbon dioxide recovery device 16 is not limited to a configuration that recovers carbon dioxide by a wet chemical absorption method. The carbon dioxide recovery device 16 may also be configured to recover carbon dioxide by a dry physical absorption method or the like.

[0122] Furthermore, the exhaust gas treatment system 100 in the power generation equipment 1000 described in the embodiment may further include a blower (not shown) located in the exhaust gas flow path 12 or outlet flow path 18 between the dust collection equipment 14 and the chimney 17.

[0123] Furthermore, the first heat recovery unit 13 and the second heat recovery unit 15 described in the embodiment are not limited to a configuration of heat exchangers that recover heat from the exhaust gas EG by exchanging heat with a heat transfer medium introduced from the outside. The first heat recovery unit 13 and the second heat recovery unit 15 may also be temperature controllers that adjust the temperature of the exhaust gas EG by spraying water onto the exhaust gas EG, for example.

[0124] Furthermore, although the embodiment described the alkaline powder supply unit 21 as supplying slaked lime as the alkaline powder to the exhaust gas EG, it is not limited to this configuration. The alkaline powder supply unit 21 may also be configured to supply, for example, sodium bicarbonate or the like to the exhaust gas EG.

[0125] Furthermore, in this embodiment, the incinerator 10 in the waste treatment system 200 of the power generation facility 1000 is a stoker-type incinerator, but it is not limited to a stoker-type incinerator. The incinerator 10 may be, for example, a kiln-stoker furnace, a biomass fluidized bed boiler, a sludge incinerator, or the like.

[0126] <Note> The exhaust gas treatment system, power generation equipment equipped therewith, and exhaust gas treatment method described in each embodiment can be understood, for example, as follows.

[0127] (1) The exhaust gas treatment system 100 according to the first embodiment includes a denitrification layer 142 on which a denitrification catalyst is supported, a dust collection facility 14 through which the exhaust gas EG passes, and a carbon dioxide recovery device 16 located downstream of the dust collection facility 14 in the flow direction of the exhaust gas EG, wherein the exhaust gas EG is supplied from the dust collection facility 14 to the carbon dioxide recovery device 16 while maintaining a temperature below the outlet gas temperature of the dust collection facility 14.

[0128] As a result, the exhaust gas EG is denitrified in the dust collection equipment 14, eliminating the need for heating during the process from the dust collection equipment 14 to the carbon dioxide recovery device 16. Therefore, the thermal energy required for this heating can be reduced. In addition, since sulfur oxides in the exhaust gas EG are removed in the denitrification layer 142 of the dust collection equipment 14 upstream of the carbon dioxide recovery device 16, the increase in the consumption of absorbent liquid from which impurities are absorbed in the carbon dioxide recovery device 16 can be suppressed.

[0129] (2) The exhaust gas treatment system 100 according to the second embodiment is the exhaust gas treatment system 100 of (1), and may include: a first heat recovery unit 13 located upstream of the dust collection equipment 14 in the flow direction of the exhaust gas EG and which exchanges heat between the exhaust gas EG and a heat transfer medium; a sensor 400 having one or more of a first thermometer 41 capable of detecting the temperature of the exhaust gas EG flowing between the first heat recovery unit 13 and the dust collection equipment 14, and a second thermometer 42 capable of detecting the temperature of the exhaust gas EG flowing between the dust collection equipment 14 and the carbon dioxide recovery device 16; and a control device 500 that controls the amount of the heat transfer medium supplied to the first heat recovery unit 13 based on the detection result of one or more of the first thermometer 41 and the second thermometer 42 and a gas temperature threshold Tx.

[0130] This makes it possible to stabilize the temperature of the exhaust gas EG introduced into the dust collection equipment 14.

[0131] (3) The exhaust gas treatment system 100 according to the third embodiment is the exhaust gas treatment system 100 of (1), comprising: a first heat recovery unit 13 located upstream of the dust collection equipment 14 in the flow direction of the exhaust gas EG, which exchanges heat between the exhaust gas EG and a heat transfer medium; a bypass line 23 which can direct at least a portion of the exhaust gas EG flowing into the first heat recovery unit 13 to the exhaust gas EG flowing between the first heat recovery unit 13 and the dust collection equipment 14 without passing through the first heat recovery unit 13; and the bypass line 23, which is arranged in the bypass line 23. The system may also include a flow regulator 24 capable of adjusting the flow rate of the exhaust gas EG flowing through the 23, a sensor 400 having one or more of the following: a first thermometer 41 capable of detecting the temperature of the exhaust gas EG flowing between the first heat recovery unit 13 and the dust collection equipment 14, and a second thermometer 42 capable of detecting the temperature of the exhaust gas EG flowing between the dust collection equipment 14 and the carbon dioxide recovery device 16, and a control device 500 that controls the opening degree of the flow regulator 24 based on the detection result of one or more of the first thermometer 41 and the second thermometer 42 and a gas temperature threshold Tx.

[0132] This makes it possible to stabilize the temperature of the exhaust gas EG introduced into the dust collection equipment 14.

[0133] (4) The exhaust gas treatment system 100 according to the fourth embodiment is the exhaust gas treatment system 100 of (2) or (3), wherein the sensor 400 has one or more of the following: a nitrogen oxide concentration detection unit 44 capable of detecting the nitrogen oxide concentration A1 in the exhaust gas EG and a sulfur oxide concentration detection unit 45 capable of detecting the sulfur oxide concentration A2 in the exhaust gas EG, and the control device 500 may change the gas temperature threshold Tx based on the detection result of one or more of the nitrogen oxide concentration detection unit 44 and the sulfur oxide concentration detection unit 45.

[0134] This controls the temperature of the exhaust gas EG to one or more of the nitrogen oxide concentration A1 and sulfur oxide concentration A2. As a result, the amount of power used in the exhaust gas treatment system 100 can be optimized.

[0135] (5) The exhaust gas treatment system 100 according to the fifth embodiment is any of the exhaust gas treatment systems 100 from (1) to (4), and may include a second heat recovery unit 15 located between the dust collection equipment 14 and the carbon dioxide recovery device 16 in the flow direction of the exhaust gas EG, which exchanges heat between the exhaust gas EG and the heat transfer medium.

[0136] This makes it possible to further stabilize the temperature of the exhaust gas EG flowing from the second heat recovery unit 15 to the carbon dioxide recovery unit 16 within the exhaust gas flow path 12. Therefore, it is possible to improve the denitrification performance of the exhaust gas EG in the denitrification layer 142 of the dust collection equipment 14 while suppressing a decrease in power generation efficiency.

[0137] (6) The exhaust gas treatment system 100 according to the sixth embodiment is the exhaust gas treatment system 100 of (5), which may include a sensor 400 having a third thermometer 43 capable of detecting the temperature of the exhaust gas EG flowing between the second heat recovery unit 15 and the carbon dioxide recovery device 16, and a control device 500 that controls the amount of the heat transfer medium supplied to the second heat recovery unit 15 based on the detection result of the sensor 400 and a gas temperature threshold Ty.

[0138] This allows for stabilization of the amount of heat recovered from the exhaust gas EG. Furthermore, it allows for stabilization of the temperature of the exhaust gas EG flowing into the carbon dioxide recovery device 16.

[0139] (7) The exhaust gas treatment system 100 according to the seventh embodiment is any of the exhaust gas treatment systems 100 from (1) to (6), and may include a reducing agent supply unit 19 capable of supplying a reducing agent to the exhaust gas EG that flows upstream of the dust collection equipment 14 in the flow direction of the exhaust gas EG.

[0140] As a result, the reducing agent supplied to the exhaust gas EG directly reacts with nitrogen oxides in the exhaust gas EG to remove them. The reducing agent supplied to the exhaust gas EG also passes through the denitrification equipment together with the exhaust gas EG. At this time, the reducing agent comes into contact with the denitrification catalyst in the denitrification layer 142, and nitrogen oxides are removed by the catalytic action of the denitrification layer 142 in the dust collection equipment 14. In other words, the denitrification catalyst is regenerated by the action of the reducing agent on it.

[0141] (8) The exhaust gas treatment system 100 according to the eighth embodiment is any of the exhaust gas treatment systems 100 from (1) to (7), and may include an activated carbon supply unit 20 capable of supplying activated carbon to the exhaust gas EG that flows upstream of the dust collection equipment 14 in the flow direction of the exhaust gas EG.

[0142] As a result, impurities such as mercury contained in the exhaust gas EG are adsorbed onto the activated carbon. Therefore, the retention of impurities such as mercury in the exhaust gas EG passing through the dust collection equipment 14 is suppressed, and as a result, the inflow of impurities into the absorbent liquid in the carbon dioxide recovery device 16 can be suppressed. Therefore, the contamination of carbon dioxide recovered by the carbon dioxide recovery device 16 with impurities and the deterioration of the absorbent liquid can be reduced.

[0143] (9) The exhaust gas treatment system 100 according to the ninth embodiment is any of the exhaust gas treatment systems 100 from (1) to (8), and may include an alkaline powder supply unit 21 capable of supplying alkaline powder to the exhaust gas EG flowing upstream of the dust collection equipment 14 in the flow direction of the exhaust gas EG.

[0144] As a result, sulfur oxides contained in the exhaust gas EG react with the alkaline powder to form calcium sulfate. Therefore, it is possible to suppress contact between sulfur oxides contained in the exhaust gas EG and the denitrification catalyst in the dust collection equipment 14.

[0145] (10) The exhaust gas treatment system 100 according to the tenth embodiment is any exhaust gas treatment system 100 from (1) to (9), comprising an alkaline agent supply unit 22 capable of supplying an alkaline agent to the carbon dioxide recovery device 16, wherein the carbon dioxide recovery device 16 may include a cooling tower 161 that cools the exhaust gas EG and adds the alkaline agent from the alkaline agent supply unit 22 to the cooling tower circulating water, an absorption tower 162 that allows the carbon dioxide contained in the cooled exhaust gas EG to be absorbed into an absorption liquid, and a regeneration tower 163 that heats the absorption liquid from which the carbon dioxide has been absorbed by a reboiler 163b supplied with a heat transfer medium and separates the carbon dioxide from the absorption liquid.

[0146] As a result, the exhaust gas EG in the cooling tower 161 is desulfurized and desalted. Since desulfurization and desalting can be performed in the cooling tower 161, the amount of alkaline powder supplied, for example, upstream of the dust collection equipment 14 can be reduced. In addition, the amount of solid waste discharged can be reduced. Furthermore, because the amount of chemical sprayed is reduced, the differential pressure in the dust collection equipment becomes smaller, and the backwashing interval is extended, thus extending the lifespan of the dust collection equipment 14.

[0147] (11) The power generation equipment 1000 according to the eleventh embodiment is a power generation equipment 1000 that generates electricity by incinerating materials to be incinerated, comprising: an incinerator 10 in which the materials to be incinerated are incinerated; a boiler located upstream of the dust collection equipment 14 in the flow direction of the exhaust gas EG and to which the exhaust gas EG generated in the incinerator 10 is supplied; and an exhaust gas treatment system 100 according to claim 7 into which the exhaust gas EG that has passed through the boiler is introduced, wherein the exhaust gas treatment system 100 comprises a reducing agent introduction line 25 connecting the carbon dioxide recovery device 16 and the boiler, and the carbon dioxide recovery device 16 is the exhaust gas The reducing agent introduction line 25 includes a cooling tower 161 for cooling the exhaust gas EG, an absorption tower 162 for absorbing carbon dioxide contained in the cooled exhaust gas EG into an absorbent liquid, a regeneration tower 163 for heating the absorbent liquid that has absorbed the carbon dioxide with a reboiler 163b supplied with a heat transfer medium and separating the carbon dioxide from the absorbent liquid, and a reclaimer 164 for dividing the absorbent liquid from the regeneration tower 163 into a first liquid in which impurities are concentrated and a second liquid from which impurities have been separated. The reducing agent introduction line 25, as the reducing agent supply unit 19, supplies the first liquid from the reclaimer 164 as the reducing agent into the incinerator 10.

[0148] As a result, the first liquid, which is wastewater from the carbon dioxide recovery device 16, is used as a reducing agent. Therefore, the first liquid can be effectively disposed of in the incinerator 10. In addition, since the reducing agent introduction line 25 functions as a reducing agent supply unit 19, the amount of reducing agent handled by the reducing agent supply unit 19 can be reduced.

[0149] (12) An exhaust gas treatment method according to a twelfth embodiment is an exhaust gas treatment method used in equipment that generates exhaust gas EG, wherein the equipment includes a denitrification layer 142 on which a denitrification catalyst is supported, a dust collection equipment 14 through which the exhaust gas EG passes, and a carbon dioxide recovery device 16 located downstream of the dust collection equipment 14 in the flow direction of the exhaust gas EG, and the exhaust gas treatment method includes supplying the carbon dioxide from the dust collection equipment 14 to the carbon dioxide recovery device 16 while maintaining a state at or below the outlet gas temperature of the dust collection equipment 14. [Explanation of Symbols]

[0150] 1…Furnace body 2…Fuel supply mechanism 3…Furnace 10…Incinerator 11…Waste heat recovery boiler 12…Exhaust gas flow path 13…First heat recovery unit 14…Dust collection equipment 13a…Second heat transfer valve 15…Second heat recovery unit 15a…First heat transfer valve 16…Carbon dioxide recovery device 17…Chimney 18…Outlet flow path 19…Reducing agent supply unit 20…Activated carbon supply unit 21…Alkaline powder supply unit 22…Alkaline agent supply unit 23…Bypass line 23a…One end 23b…Other end 24…Flow regulator 25…Reducing agent introduction line 30a…Main steam line 30b…Boiler feedwater line 30c…First connection line 30d…Second connection line 30e…Third connection line 30g…First feedwater bypass line 30h…Second feedwater bypass line 31…Steam turbine 32...Condenser 33a...First feedwater pump 33b...Second feedwater pump 34...Deaerator 41...First thermometer 42...Second thermometer 43...Third thermometer 44...Nitrogen oxide concentration detection unit 45...Sulfur oxide concentration detection unit 51...Detection unit 52...Determination unit 53...Setting unit 54,54a...Control unit 55...Memory unit 100...Exhaust gas treatment system 141...Dust collection equipment main unit 142...Denitrification layer 161...Cooling tower 162...Absorption tower 163...Regeneration tower 163a...Regeneration tower main unit 163b...Reboiler 164...Reclaimer 191...Reducing agent supply source 192...Reducing agent supply line 200...Waste treatment system 201...Activated carbon supply source 202...Activated carbon supply line 211...Alkaline powder supply source 212…Alkaline powder supply line 221…Alkaline agent supply source 222…Alkaline agent supply line 300…Power generation system 400…Sensor 500…Control device 1000…Power generation equipment 1100…Computer 1110…Processor 1120…Main memory 1130…Storage 1140…Interface A1…Nitrogen oxide concentration A2…Sulfur oxide concentration EG…Exhaust gas GEN…Generator T1…First temperature T2…Second temperature T3…Third temperature

Claims

1. A dust collection system that includes a denitrification layer on which a denitrification catalyst is supported, through which exhaust gas passes, A carbon dioxide recovery device located downstream of the dust collection equipment in the flow direction of the exhaust gas, A first heat recovery unit is located upstream of the dust collection equipment in the flow direction of the exhaust gas and performs heat exchange between the exhaust gas and the heat transfer medium. A sensor having one or more of the following: a first thermometer capable of detecting the temperature of the exhaust gas flowing between the first heat recovery unit and the dust collection equipment, and a second thermometer capable of detecting the temperature of the exhaust gas flowing between the dust collection equipment and the carbon dioxide recovery device. A control device that controls the amount of the heat transfer medium supplied to the first heat recovery unit based on the detection results of one or more of the first and second thermometers and a gas temperature threshold, Equipped with, The exhaust gas is supplied from the dust collection equipment to the carbon dioxide recovery device while maintaining a temperature below the outlet gas temperature of the dust collection equipment. Exhaust gas treatment system.

2. A dust collection system comprising a denitrification layer on which a denitrification catalyst is supported, through which exhaust gas passes, A carbon dioxide recovery device located downstream of the dust collection equipment in the flow direction of the exhaust gas, A first heat recovery unit is located upstream of the dust collection equipment in the flow direction of the exhaust gas and performs heat exchange between the exhaust gas and the heat transfer medium. A bypass line that allows at least a portion of the exhaust gas flowing into the first heat recovery unit to be merged with the exhaust gas flowing between the first heat recovery unit and the dust collection equipment without passing through the first heat recovery unit, A flow regulator is provided in the bypass line and capable of adjusting the flow rate of the exhaust gas flowing through the bypass line, A sensor having one or more of the following: a first thermometer capable of detecting the temperature of the exhaust gas flowing between the first heat recovery unit and the dust collection equipment, and a second thermometer capable of detecting the temperature of the exhaust gas flowing between the dust collection equipment and the carbon dioxide recovery device. A control device that controls the opening degree of the flow regulator based on one or more detection results from the first thermometer and the second thermometer and a gas temperature threshold, Equipped with, The exhaust gas is supplied from the dust collection equipment to the carbon dioxide recovery device while maintaining a temperature below the outlet gas temperature of the dust collection equipment. Exhaust gas treatment system.

3. The sensor has one or more of the following: a nitrogen oxide concentration detection unit capable of detecting the nitrogen oxide concentration in the exhaust gas, and a sulfur oxide concentration detection unit capable of detecting the sulfur oxide concentration in the exhaust gas. The control device changes the gas temperature threshold based on one or more detection results from the nitrogen oxide concentration detection unit and the sulfur oxide concentration detection unit. The exhaust gas treatment system according to claim 1 or claim 2.

4. The system includes a second heat recovery unit located between the dust collection equipment and the carbon dioxide recovery device in the direction of the exhaust gas flow, which exchanges heat between the exhaust gas and the heat transfer medium. The exhaust gas treatment system according to claim 1 or claim 2.

5. A sensor having a third thermometer capable of detecting the temperature of the exhaust gas flowing between the second heat recovery unit and the carbon dioxide recovery device, A control device that controls the amount of the heat transfer medium supplied to the second heat recovery unit based on the detection result of the sensor and the gas temperature threshold, The exhaust gas treatment system according to claim 4, comprising:

6. The system includes a reducing agent supply unit capable of supplying a reducing agent to the exhaust gas flowing upstream of the dust collection equipment in the direction of the exhaust gas flow. The exhaust gas treatment system according to claim 1 or claim 2.

7. The system includes an activated carbon supply unit capable of supplying activated carbon to the exhaust gas flowing upstream of the dust collection equipment in the direction of the exhaust gas flow. The exhaust gas treatment system according to claim 1 or claim 2.

8. The system includes an alkaline powder supply unit capable of supplying alkaline powder to the exhaust gas flowing upstream of the dust collection equipment in the direction of the exhaust gas flow. The exhaust gas treatment system according to claim 1 or claim 2.

9. The carbon dioxide recovery device is equipped with an alkaline agent supply unit capable of supplying an alkaline agent, The carbon dioxide recovery device is A cooling tower that cools the exhaust gas while adding the alkaline agent from the alkaline agent supply unit to the cooling tower circulating water, An absorption tower that absorbs carbon dioxide contained in the cooled exhaust gas into an absorbent liquid, A regeneration tower is provided which heats the absorbent liquid that has absorbed the carbon dioxide using a reboiler supplied with a heat transfer medium, and separates the carbon dioxide from the absorbent liquid. had The exhaust gas treatment system according to claim 1 or claim 2.

10. A power generation facility that generates electricity by incinerating materials, An incinerator in which the aforementioned materials to be incinerated are incinerated, A boiler located upstream of the dust collection equipment in the direction of the exhaust gas flow, to which the exhaust gas generated in the incinerator is supplied, An exhaust gas treatment system according to claim 1 or claim 2, wherein the exhaust gas that has passed through the boiler is introduced, Equipped with, The carbon dioxide recovery device is A cooling tower for cooling the exhaust gas, An absorption tower that absorbs carbon dioxide contained in the cooled exhaust gas into an absorbent liquid, A regeneration tower is provided which heats the absorbent liquid that has absorbed the carbon dioxide using a reboiler supplied with a heat transfer medium, and separates the carbon dioxide from the absorbent liquid. A reclaimer that separates the absorbent liquid from the regeneration tower into a first liquid in which impurities are concentrated and a second liquid from which impurities have been separated, It has, The exhaust gas treatment system includes a reducing agent introduction line that supplies the first liquid from the reclaimer into the incinerator. Power generation equipment.

11. An exhaust gas treatment method using the exhaust gas treatment system described in Claim 1, The exhaust gas is supplied from the dust collection equipment to the carbon dioxide recovery device while maintaining a temperature below the outlet gas temperature of the dust collection equipment. This includes controlling the amount of the heat transfer medium supplied to the first heat recovery unit based on the detection results of one or more of the first and second thermometers and a gas temperature threshold. Exhaust gas treatment method.

12. An exhaust gas treatment method using the exhaust gas treatment system described in Claim 2, The exhaust gas is supplied from the dust collection equipment to the carbon dioxide recovery device while maintaining a temperature below the outlet gas temperature of the dust collection equipment. This includes controlling the opening degree of the flow regulator based on one or more detection results from the first thermometer and the second thermometer and a gas temperature threshold. Exhaust gas treatment method.

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