Cooling tower, carbon dioxide recovery device, and method for protecting cooling tower filler

Abstract

This cooling tower cools exhaust gas and comprises: a resin cooling tower filler that cools the exhaust gas flowing inside the cooling tower upward from below in a vertical direction; a condensed water circulation unit having a condensed water circulation flow path that pumps up condensed water stored below the cooling tower by a pump and circulates the condensed water upward the cooling tower, and a heat exchanger that cools the condensed water flowing through the condensed water circulation flow path; a condensed water dispersion unit that is connected to the condensed water circulation flow path above the cooling tower and supplies the condensed water to the cooling tower filler from above the cooling tower filler; and a cooling unit having a cooling water dispersion unit that supplies cooling water for cooling the exhaust gas to the upstream side of the cooling tower filler in the exhaust gas circulation direction.

Description

Cooling Tower, Carbon Dioxide Recovery Device, and Method for Protecting Cooling Tower Packing

[0001] The present disclosure relates to a cooling tower, a carbon dioxide recovery device, and a method for protecting a cooling tower packing. This application claims priority to U.S. Application No. 18 / 885,978, filed on September 16, 2024, the content of which is incorporated herein by reference.

[0002] A carbon dioxide recovery device that removes and recovers carbon dioxide from exhaust gas includes a cooling tower that cools the exhaust gas, an absorption tower that absorbs and recovers carbon dioxide contained in the cooled exhaust gas into an absorption liquid, and a regeneration tower that separates and regenerates carbon dioxide from the absorption liquid that has absorbed carbon dioxide. The absorption tower is provided inside with a gas-liquid contact plate and a nozzle that sprays the absorption liquid onto the gas-liquid contact plate. The cooling tower is provided inside with a gas-liquid contact plate and a nozzle that sprays cooling water onto the gas-liquid contact plate. Generally, the gas-liquid contact plate (packing) is made of a metal material, but since the metal gas-liquid contact plate is heavy, the structure that supports the gas-liquid contact plate becomes large. For this reason, for example, Patent Document 1 and Patent Document 2 describe techniques for using a resin material that is lighter than a metal material for the gas-liquid contact plate.

[0003] Japanese Patent No. 5794775 U.S. Patent No. 4950430 Specification

[0004] However, a resin-made gas-liquid contact plate (packing) has lower heat resistance and a larger linear expansion coefficient than a metal-made one. For this reason, when high-temperature exhaust gas is introduced or when the temperature rises due to heat generation when the absorption liquid absorbs carbon dioxide, deformation or damage may occur. Also, melting or damage may occur during welding operations such as maintenance.

[0005] The present disclosure provides a cooling tower, a carbon dioxide recovery device, and a method for protecting a cooling tower packing that can suppress high-temperature exhaust gas exceeding the heat-resistant temperature from flowing through the resin-made cooling tower packing.

[0006] According to one aspect of the present disclosure, a cooling tower is a cooling tower for cooling exhaust gas, comprising: a condensate circulation section having a resin cooling tower packing material for cooling the exhaust gas flowing vertically from bottom to top inside the cooling tower; a condensate circulation channel for pumping up condensate stored at the bottom of the cooling tower and circulating it to the top of the cooling tower; and a heat exchanger for cooling the condensate flowing through the condensate circulation channel; a condensate distribution section connected to the condensate circulation channel at the top of the cooling tower and supplying the condensate from above the cooling tower packing material to the cooling tower packing material; and a cooling section having a cooling water distribution section that supplies cooling water for cooling the exhaust gas upstream of the cooling tower packing material in the flow direction of the exhaust gas.

[0007] According to one aspect of the present disclosure, the carbon dioxide recovery apparatus comprises a cooling tower, an absorption tower that removes carbon dioxide contained in the exhaust gas cooled by the cooling tower by absorbing it into an absorbent liquid, and a regeneration tower that regenerates the absorbent liquid by separating the carbon dioxide from the absorbent liquid discharged from the absorption tower.

[0008] According to one aspect of the present disclosure, a method for protecting a resin cooling tower packing material that cools exhaust gas flowing inside a cooling tower includes the steps of: pumping up condensed water stored at the bottom of the cooling tower and circulating it upward through a condensed water circulation channel, and cooling the condensed water flowing through the condensed water circulation channel with a heat exchanger; supplying the condensed water from above the cooling tower packing material to the cooling tower packing material from a condensed water distribution unit connected to the condensed water circulation channel at the top of the cooling tower; and supplying cooling water to cool the exhaust gas to the cooling tower packing material upstream of the cooling tower packing material in the flow direction of the exhaust gas.

[0009] According to the above-described embodiment, it is possible to suppress the flow of high-temperature exhaust gas exceeding the heat resistance temperature into the resin-based cooling tower packing material.

[0010] This is a schematic diagram showing the overall configuration of a carbon dioxide recovery system according to the first embodiment of this disclosure. This is a first schematic diagram showing an example of the configuration of a cooling tower according to the first embodiment of this disclosure. This is a second schematic diagram showing an example of the configuration of a cooling tower according to the first embodiment of this disclosure. This is a third schematic diagram showing an example of the configuration of a cooling tower according to the first embodiment of this disclosure. This is a fourth schematic diagram showing an example of the configuration of a cooling tower according to the first embodiment of this disclosure. This is a flowchart showing an example of the processing of a cooling tower control unit according to the first embodiment of this disclosure. This is a first schematic diagram showing an example of the configuration of a carbon dioxide recovery device according to the second embodiment of this disclosure. This is a second schematic diagram showing an example of the configuration of a carbon dioxide recovery device according to the second embodiment of this disclosure. This is a schematic block diagram showing the configuration of a control unit computer according to at least one embodiment.

[0011] <First Embodiment> The carbon dioxide capture system according to the first embodiment of this disclosure will be described in detail below with reference to Figures 1 to 6.

[0012] (Overall Configuration of the Carbon Dioxide Capture System) Figure 1 is a schematic diagram showing the overall configuration of a carbon dioxide capture system according to the first embodiment of the present disclosure. The carbon dioxide capture system 100 captures carbon dioxide from exhaust gas G1 emitted by the combustion equipment 10 of the plant 1. The combustion equipment 10 is equipment that burns fuel and air to emit exhaust gas G1, and can be any type of equipment, such as a boiler, incinerator, or gas turbine. The carbon dioxide capture system 100 includes a carbon dioxide capture device 4.

[0013] The carbon dioxide recovery system 4 is installed downstream of the combustion equipment 10. The carbon dioxide recovery system 4 comprises a cooling tower 5, an absorption tower 6, and a regeneration tower 7. The cooling tower 5 cools the exhaust gas G1. The absorption tower 6 removes the carbon dioxide contained in the exhaust gas G1 cooled by the cooling tower 5 by absorbing it into an absorbent liquid. The absorption tower 6 discharges the purified gas G2, from which carbon dioxide has been removed, to the outside of the system (atmosphere) and also discharges the absorbent liquid that has absorbed carbon dioxide to the regeneration tower 7. The regeneration tower 7 separates carbon dioxide from the absorbent liquid discharged by the absorption tower 6 and regenerates the absorbent liquid. The regeneration tower 7 returns the regenerated absorbent liquid to the absorption tower 6 and discharges the separated carbon dioxide to the outside of the system. The carbon dioxide discharged from the regeneration tower 7 is stored in a recovery tank or the like and used in other systems.

[0014] Although Figure 1 shows an example in which exhaust gas G1 discharged from the combustion equipment 10 is directly introduced into the carbon dioxide recovery device 4, the system is not limited to this configuration. The carbon dioxide recovery system 100 may also include, as needed, pretreatment equipment for exhaust gas G1, such as a dust collector to remove soot and other particles contained in the exhaust gas G1, or a desulfurization device to remove sulfur oxides (SOx) contained in the exhaust gas G1, between the combustion equipment 10 and the carbon dioxide recovery device 4.

[0015] (Example of Cooling Tower Configuration 1) Figure 2 is a schematic diagram showing an example of the configuration of a cooling tower according to the first embodiment of the present disclosure. As shown in Figure 2, the cooling tower 5 comprises a main body 50, a cooling tower packing material 51, a condensate circulation unit 52, a condensate dispersion unit 53, a cooling unit 54, and a cooling tower control unit 56.

[0016] The main body 50 is a hollow container extending vertically, through which exhaust gas G1 flows vertically. Below the main body 50 (upstream in the direction of exhaust gas G1 flow), an exhaust gas introduction channel 50A is connected to introduce the exhaust gas G1, which has been processed by the dust collector 2 and the desulfurization device 3, into the main body 50. Above the main body 50 (downstream in the direction of exhaust gas G1 flow), an exhaust gas discharge channel 50B is connected to discharge the exhaust gas G1, which has been cooled inside the main body 50, to the absorption tower 6. A blower (not shown) is provided between the cooling tower 5 and the absorption tower 6 (downstream of the exhaust gas discharge channel 50B), and the blower draws the exhaust gas into the absorption tower 6. Below the main body 50, condensed water produced when moisture contained in the exhaust gas G1 is cooled is stored.

[0017] The cooling tower packing material 51 is provided inside the main body 50. The cooling tower packing material 51 is made of a resin material.

[0018] The condensate circulation unit 52 uses a pump 522 to draw up condensate stored below the main body 50 and circulates it upwards through the condensate circulation channel 521. The condensate circulation channel 521 is equipped with a heat exchanger 523 that cools the condensate drawn up by the pump 522 to a predetermined temperature. The lower part of the condensate circulation channel 521 is the upstream side in the direction of condensate flow, and the upper part is the downstream side in the direction of condensate flow.

[0019] The condensate dispersion unit 53 is connected to the condensate circulation channel 521 above the main body 50. The condensate dispersion unit 53 is positioned above the cooling tower packing material 51 and supplies condensate cooled in the condensate circulation unit 52 to the cooling tower packing material 51. As a result, the condensate supplied from the condensate dispersion unit 53 flows from the top to the bottom of the cooling tower packing material 51. The exhaust gas G1 flowing from the bottom to the top of the main body 50 comes into gas-liquid contact with the condensate flowing through the cooling tower packing material 51 and is cooled.

[0020] The cooling section 54 has a cooling water distribution section 543 that supplies cooling water to cool the exhaust gas G1 upstream of the cooling tower packing material 51 in the flow direction of the exhaust gas G1. In the example shown in Figure 2, the cooling water distribution section 543 is provided inside the exhaust gas introduction channel 50A and supplies cooling water into the exhaust gas introduction channel 50A.

[0021] With this configuration, the cooling unit 54 can lower the temperature of the exhaust gas G1 with cooling water in the exhaust gas introduction passage 50A before the exhaust gas G1 flows into the main body 50 of the cooling tower 5. This prevents high-temperature exhaust gas G1 exceeding the heat resistance temperature from flowing into the resin cooling tower packing material 51. As a result, the risk of deformation or damage to the cooling tower packing material 51 is reduced, and the lifespan of the cooling tower packing material 51 can be extended.

[0022] The cooling unit 54 may also supply cooling water to the cooling water distribution unit 543 by introducing cooling water from outside the system. Alternatively, the cooling unit 54 may utilize a portion of the condensate circulating in the condensate circulation unit 52 as cooling water, as shown in the example in Figure 2. For example, as shown in Figure 2, the cooling unit 54 has a cooling water channel 541 that branches off from a position downstream of the heat exchanger 523 in the condensate circulation channel 521 and introduces a portion of the condensate cooled in the heat exchanger 523 as cooling water to the cooling water distribution unit 543. By reusing condensate water in this way, the cooling unit 54 does not need to introduce cooling water from outside the system, and the operating costs of the cooling tower can be reduced. In addition, since the condensate cooled by the heat exchanger 523 of the condensate circulation unit 52 is used as cooling water, the temperature of the exhaust gas G1 can be effectively reduced.

[0023] The cooling unit 54 may be configured to always supply cooling water from the cooling water distribution unit 543 while the cooling tower 5 is in operation. In this configuration, where cooling water is always supplied, the cooling tower control unit 56, which will be described later, may be omitted. Alternatively, the cooling unit 54 may be configured to supply cooling water from the cooling water distribution unit 543 when the temperature of the exhaust gas G1 becomes high, in accordance with the control of the cooling tower control unit 56. For example, as shown in Figure 2, a cooling water control valve 542 is provided in the cooling water flow path 541. The cooling water control valve 542 starts or stops the supply of cooling water by opening and closing in accordance with the control of the cooling tower control unit 56. In addition, the amount of cooling water supplied can be increased or decreased by changing the opening degree of the cooling water control valve 542 in accordance with the control of the cooling tower control unit 56.

[0024] The cooling tower control unit 56 supplies cooling water to the cooling water distribution unit 543 of the cooling unit 54 when the temperature of the exhaust gas G1 exceeds a limit temperature corresponding to the heat resistance temperature of the cooling tower packing material 51. The detailed functions (processing examples) of the cooling tower control unit 56 will be described later.

[0025] Furthermore, the main body 50 is provided with a first thermometer 501 and at least one of two second thermometers 502, 503 for measuring the temperature of the exhaust gas G1. Figure 2 shows an example in which both the first thermometer 501 and the second thermometers 502, 503 are provided, but in any other embodiment, it is sufficient to provide at least one of the first thermometer 501 and the second thermometers 502, 503. Note that if the cooling tower control unit 56 is omitted as described above, neither the first thermometer 501 nor the second thermometers 502, 503 may be installed. The first thermometer 501 is provided near the outlet of the exhaust gas introduction passage 50A (near the inlet of the main body 50) and measures the temperature of the exhaust gas G1 introduced into the main body 50. The second thermometers 502 and 503 measure the temperature of the exhaust gas G1 introduced into the cooling tower packing material 51 below the cooling tower packing material 51 (upstream in the flow direction of the exhaust gas G1). The second thermometers 502 and 503 are installed at least two different horizontal positions below the cooling tower packing material 51, for example, as shown in Figure 2, to account for the possibility of temperature unevenness in the cooling tower packing material 51. This prevents missed detection of temperature increases in the exhaust gas G1 even when the temperature of the exhaust gas G1 differs depending on the horizontal position (temperature unevenness occurs).

[0026] (Example of Cooling Tower Configuration 2) Figure 3 is a second schematic diagram showing an example of the configuration of a cooling tower according to the first embodiment of the present disclosure. The cooling section 54 may be configured as shown in Figure 3 instead of the configuration in Figure 2. The configuration of the cooling water flow path 541 and the cooling water control valve 542 is the same as in Figure 2.

[0027] In the example shown in Figure 3, the cooling water distribution unit 543 is located inside the main body 50, below the cooling tower packing material 51. The cooling water distribution unit 543 supplies cooling water to the cooling tower packing material 51 from below.

[0028] With this configuration, the cooling unit 54 cools the lower side of the cooling tower packing material 51 with cooling water along with the exhaust gas G1, thereby preventing the exhaust gas G1 and the cooling tower packing material 51 from exceeding the heat resistance temperature of the cooling tower packing material 51. Furthermore, the temperature of the exhaust gas G1 is higher towards the lower side of the cooling tower packing material 51 (upstream side in the flow direction). Therefore, by supplying cooling water towards the area where the temperature of the cooling tower packing material 51 tends to rise, the temperatures of the exhaust gas G1 and the cooling tower packing material 51 can be appropriately reduced.

[0029] (Example of Cooling Tower Configuration 3) Figure 4 is a third schematic diagram showing an example of the configuration of a cooling tower according to the first embodiment of the present disclosure. The cooling section 54 may be configured as shown in Figure 4 instead of the configuration in Figure 2 or Figure 3. The configuration of the cooling water flow path 541 and the cooling water control valve 542 is the same as in Figure 2.

[0030] In the example shown in Figure 4, the cooling section 54 further includes a second cooling tower packing material 544 located inside the main body 50, below the cooling tower packing material 51 and spaced apart from it. The second cooling tower packing material 544 has a higher heat resistance temperature than the cooling tower packing material 51. Specifically, the second cooling tower packing material 544 is a metal packing material with a higher heat resistance temperature than the resin cooling tower packing material 51.

[0031] Furthermore, the cooling water distribution unit 543 is provided inside the main body 50, between the cooling tower packing material 51 and the second cooling tower packing material, and supplies cooling water to the second cooling tower packing material 544 from above.

[0032] With this configuration, the cooling unit 54 can lower the temperature of the exhaust gas G1 with the second cooling tower packing material 544, which has a high heat resistance temperature, before the exhaust gas G1 flows through the cooling tower packing material 51. Furthermore, by cooling the second cooling tower packing material 544 with cooling water, the temperature of the exhaust gas G1 can be lowered more reliably before it reaches the cooling tower packing material 51.

[0033] (Example of Cooling Tower Configuration 4) Figure 5 is a fourth schematic diagram showing an example of the configuration of a cooling tower according to the first embodiment of the present disclosure. The cooling section 54 may be configured as shown in Figure 5 instead of the configuration in Figure 4.

[0034] In the example shown in Figure 5, the second cooling tower packing material 544 of the cooling section 54 is attached to the lower end of the cooling tower packing material 51. The second cooling tower packing material 544 is a metal packing material with a higher heat resistance temperature than the cooling tower packing material 51, similar to the example shown in Figure 4.

[0035] Furthermore, Figure 5 shows an example in which the cooling water distribution unit 543 is provided in the exhaust gas introduction passage 50A, similar to Figure 2, but it is not limited to this. In other embodiments, the cooling water distribution unit 543 may be configured to supply cooling water to the second cooling tower packing material 544 from below the cooling tower packing material 51, that is, from below the second cooling tower packing material 544, similar to Figure 3. The configuration of the cooling water passage 541 and the cooling water control valve 542 is the same as in Figure 2.

[0036] Similar to the example in Figure 4, the cooling unit 54 can lower the temperature of the exhaust gas G1 with the second cooling tower packing material 544, which has a high heat resistance temperature, before the exhaust gas G1 flows through the cooling tower packing material 51. Furthermore, the temperature of the exhaust gas G1 can be lowered more effectively by cooling the second cooling tower packing material 544 with cooling water.

[0037] In the examples shown in Figures 4 and 5, the second cooling tower packing material 544 may have a shorter vertical length than the cooling tower packing material 51. By doing so, the total weight of the resin cooling tower packing material 51 and the metal second cooling tower packing material 544 can be reduced compared to the total weight when the cooling tower packing material 51 is made of metal, thereby preventing the structure supporting the packing material from becoming larger.

[0038] (Example of processing by the cooling tower control unit) Figure 6 is a flowchart showing an example of processing by the cooling tower control unit according to the first embodiment of the present disclosure. Here, an example is described in which the cooling tower control unit 56 supplies cooling water to the cooling unit 54 only when the temperature of the exhaust gas G1 becomes high.

[0039] The cooling tower control unit 56 acquires the measured values ​​of the first thermometer 501 and the second thermometers 502 and 503 at predetermined processing cycles and monitors whether the temperature of the exhaust gas G1 has reached a limit temperature corresponding to the heat resistance temperature of the cooling tower packing material 51 (step S101). The limit temperature is set, for example, to a predetermined temperature lower than the heat resistance temperature. If only one thermometer is provided (for example, if only the first thermometer 501 is provided), the cooling tower control unit 56 monitors whether the measured value of this thermometer has reached a limit temperature. If multiple thermometers are provided (for example, if second thermometers 502 and 503 are provided, or if both the first thermometer 501 and the second thermometers 502 and 503 are provided), the cooling tower control unit 56 monitors whether the measured value of any one of the thermometers has reached a limit temperature. If second thermometers 502 and 503 are provided, measuring the temperature at multiple locations can suppress the failure to detect temperature increases that occur only at specific locations when condensed water does not flow uniformly through the cooling tower packing material 51, resulting in an uneven temperature distribution.

[0040] If the temperature of the exhaust gas G1 is below the limit temperature (step S101; NO), the cooling tower control unit 56 waits until the next measurement value is obtained.

[0041] On the other hand, if the temperature of the exhaust gas G1 is above the limit temperature (step S101; YES), the cooling tower control unit 56 starts supplying cooling water to the cooling unit 54 (step S102). Specifically, the cooling tower control unit 56 opens the cooling water control valve 542 of the cooling unit 54 so that a portion of the condensed water cooled from the condensed water circulation channel 521 flows into the cooling water channel 541. The cooling tower control unit 56 adjusts the opening of the cooling water control valve 542 so that, for example, the higher the temperature of the exhaust gas G1, the greater the flow rate of the cooling water. As a result, the cooling water distribution unit 543 supplies cooling water to the exhaust gas introduction channel 50A (Figure 2 or Figure 5), below the cooling tower packing material 51 (Figure 3), or to the second cooling tower packing material 544 (Figure 4), lowering the temperature of the exhaust gas G1 before it flows to the cooling tower packing material 51.

[0042] Next, the cooling tower control unit 56 determines whether the temperature of the exhaust gas G1 has dropped below the limit temperature (step S103). If the temperature of the exhaust gas G1 has dropped below the limit temperature (step S103; YES), the cooling tower control unit 56 closes the cooling water regulating valve 542 of the cooling unit 54 to stop the supply of cooling water (step S104). Thereafter, the process of FIG. 6 is repeatedly executed for each processing cycle.

[0043] On the other hand, if the temperature of the exhaust gas G1 does not drop below the limit temperature (step S103; NO), the cooling tower control unit 56 determines whether the temperature of the exhaust gas G1 has further risen and exceeded the upper limit temperature, which is higher than the limit temperature (step S105). If the temperature of the exhaust gas G1 is less than the upper limit temperature, which is higher than the limit temperature (step S105; NO), the process returns to step S103 and waits until the next measured value is obtained.

[0044] If the temperature of the exhaust gas G1 has further risen and exceeded the upper limit temperature, which is higher than the limit temperature (step S105; YES), the cooling tower control unit 56 stops the operation of the plant 1 and stops the supply of the exhaust gas G1. The upper limit temperature may be set to an arbitrary value between, for example, the heat-resistant temperature of the cooling tower filler and the limit temperature. Thereby, when it is difficult to lower the temperature of the exhaust gas G1 only with cooling water, deformation and damage of the cooling tower filler 51 due to the exhaust gas G1 at a high temperature exceeding the upper limit temperature can be suppressed.

[0045] Note that Figure 6 is an example, and in other embodiments, some parts of the process may be added or modified. For example, the cooling tower control unit 56 performs the following process instead of, or before, steps S105 to S106. The cooling tower control unit 56 sets a predetermined second limit temperature midway between the limit temperature and the upper limit temperature. If the temperature of the exhaust gas G1 does not fall below the limit temperature (step S103; NO) and rises above the second limit temperature, the flow rate of the exhaust gas G1 is reduced. Subsequently, if the temperature of the exhaust gas G1 falls below the second limit temperature, the flow rate of the exhaust gas G1 is restored to its original level, and if it falls below the limit temperature again (step S103; YES), the supply of cooling water is stopped (step S104). Note that in the case where the process of reducing the flow rate of the exhaust gas G1 is added before steps S105 to S106, if the temperature of the exhaust gas G1 rises above the upper limit temperature despite the reduction in the flow rate of the exhaust gas G1 (step S105; YES), the operation of the plant 1 is stopped (step S106). In this way, by reducing the flow rate of exhaust gas G1 before shutting down plant 1, it is possible to suppress the decrease in the operating rate of plant 1 while suppressing deformation and damage to the cooling tower packing material 51.

[0046] In yet another embodiment, if the temperature of the exhaust gas G1 exceeds a limit temperature (step S101; YES), the operation of the plant 1 may be stopped. This makes it possible to more reliably suppress deformation and damage to the cooling tower packing material 51.

[0047] (Effects) As described above, the cooling tower 5 according to this embodiment includes a resin cooling tower packing material 51 that cools the exhaust gas G1 flowing vertically from bottom to top inside the cooling tower 5 (main body 50), a condensate water circulation section 52 having a condensate water circulation channel 521 that pumps up condensate water stored below the cooling tower 5 with a pump 522 and circulates it to the top of the cooling tower 5, and a heat exchanger 523 that cools the condensate water flowing through the condensate water circulation channel 521, a condensate water dispersion section 53 connected to the condensate water circulation channel 521 above the cooling tower 5 and supplying condensate water to the cooling tower packing material 51 from above, and a cooling section 54 having a cooling water dispersion section 543 that supplies cooling water to cool the exhaust gas G1 upstream of the cooling tower packing material 51 in the flow direction of the exhaust gas G1.

[0048] By doing so, the cooling tower 5 can suppress the high-temperature exhaust gas G1 exceeding the heat-resistant temperature from flowing through the resin-made cooling tower filler 51. As a result, the risk of deformation and damage to the cooling tower filler 51 can be reduced, and the cooling tower filler 51 can have a longer lifespan.

[0049] Further, the cooling water dispersing part 543 of the cooling part 54 supplies cooling water inside the exhaust gas introduction flow path 50A that introduces the exhaust gas G1 into the cooling tower 5.

[0050] By doing so, the cooling tower 5 can lower the temperature of the exhaust gas G1 before the exhaust gas G1 flows into the cooling tower 5. Therefore, it is possible to suppress the high-temperature exhaust gas G1 exceeding the heat-resistant temperature from flowing through the resin-made cooling tower filler 51.

[0051] Further, the cooling water dispersing part 543 of the cooling part 54 supplies cooling water to the cooling tower filler 51 from below the cooling tower filler 51.

[0052] By doing so, the cooling tower 5 cools the lower side of the cooling tower filler 51 with cooling water together with the exhaust gas G1, and suppresses the exhaust gas G1 and the cooling tower filler 51 from reaching a high temperature exceeding the heat-resistant temperature of the cooling tower filler 51. Also, the temperature of the exhaust gas G1 is higher towards the lower part (upstream side in the flow direction) of the cooling tower filler 51. For this reason, the cooling tower 5 can appropriately lower the temperatures of the exhaust gas G1 and the cooling tower filler 51 by supplying cooling water towards the location where the temperature of the cooling tower filler 51 is likely to rise.

[0053] Further, the cooling part 54 is arranged below the cooling tower filler 51 and further has a second cooling tower filler 544 having a higher heat-resistant temperature than the cooling tower filler 51.

[0054] By doing so, the cooling tower 5 can lower the temperature of the exhaust gas G1 with the second cooling tower filler 544 having a high heat-resistant temperature before the exhaust gas G1 flows through the cooling tower filler 51. Therefore, it is possible to suppress the high-temperature exhaust gas G1 exceeding the heat-resistant temperature from flowing through the resin-made cooling tower filler 51.

[0055] Furthermore, the second cooling tower packing material 544 is positioned below the cooling tower packing material 51 and spaced apart from it, and the cooling water distribution unit 543 is provided between the cooling tower packing material 51 and the second cooling tower packing material 544 to supply cooling water to the second cooling tower packing material 544.

[0056] In this way, the cooling tower 5 can more reliably lower the temperature of the exhaust gas G1 before it reaches the cooling tower packing material 51, thanks to the second cooling tower packing material 544 and the cooling water.

[0057] Furthermore, the cooling section 54 has a cooling water channel 541 that branches off from the condensate circulation channel 521 downstream of the heat exchanger 523 and introduces a portion of the condensate cooled by the heat exchanger 523 as cooling water into the cooling water distribution section 543.

[0058] By reusing the condensed water from the condensed water circulation section 52 in this manner, the cooling tower 5 does not need to introduce cooling water from outside the system, thereby reducing the operating costs of the cooling tower 5. Furthermore, since the condensed water cooled by the heat exchanger 523 of the condensed water circulation section 52 is used as cooling water, the temperature of the exhaust gas G1 can be effectively reduced.

[0059] Furthermore, the cooling tower 5 is equipped with a cooling tower control unit 56 that supplies cooling water to the cooling unit 54 when the temperature of the exhaust gas G1 is above a limit temperature, and stops supplying cooling water to the cooling unit 54 when the temperature of the exhaust gas G1 is below the limit temperature.

[0060] In this way, the cooling tower 5 can lower the temperature of the exhaust gas G1 with cooling water when the temperature of the exhaust gas G1 exceeds the limit temperature, and can stop supplying cooling water when the temperature of the exhaust gas G1 is below the limit temperature, thereby reducing the pump power required for supply.

[0061] Furthermore, the cooling tower control unit 56 stops the operation of the plant 1 if the temperature of the exhaust gas G1 exceeds the upper limit temperature, which is higher than the limit temperature.

[0062] In this way, even when it is difficult to lower the temperature of the exhaust gas G1 with cooling water alone, the cooling tower 5 can suppress deformation and damage to the cooling tower packing material 51 caused by high-temperature exhaust gas G1 exceeding the upper limit temperature.

[0063] <Second Embodiment> Next, the second embodiment will be described in detail with reference to Figures 7 and 8. Components common to the above-described embodiment are denoted by the same reference numerals and their detailed descriptions are omitted.

[0064] (Example of Absorption Tower and Regeneration Tower Configuration) Figure 7 is a first schematic diagram showing an example of the configuration of a carbon dioxide recovery device according to the second embodiment of the present disclosure. First, an example of the configuration of the absorption tower 6 will be described. As shown in Figure 7, the absorption tower 6 comprises a main body 60, an absorption tower packing material 61, an absorbent liquid dispersion section 63, an absorption tower water washing section 64, and a purified gas discharge channel 65.

[0065] The main body 60 is a hollow container extending vertically, through which exhaust gas G1 cooled by the cooling tower 5 flows vertically. The absorption tower packing material 61 is a packing material provided inside the main body 60. The absorbent liquid dispersion unit 63 supplies the absorbent liquid (lean absorbent liquid) regenerated in the regeneration tower 7 to the absorption tower packing material 61. In the absorption tower packing material 61, the exhaust gas G1 and the absorbent liquid come into gas-liquid contact, and the carbon dioxide contained in the exhaust gas G1 is absorbed and removed by the absorbent liquid. The absorption tower washing unit 64 washes the exhaust gas from which the carbon dioxide has been removed with washing water and discharges it as purified gas G2 from the purified gas discharge channel 65 at the top of the absorption tower 6.

[0066] The wash water used in the absorption tower washing section 64 is stored in a chimney tray 645 located between the absorption tower packing material 61 and the absorption tower washing section 64. The wash water stored in the chimney tray 645 is pumped up by a pump 642 and supplied from above the absorption tower washing section 644 through a wash water circulation channel 641. A heat exchanger 643 is also provided in the wash water circulation channel 641 to cool the wash water supplied to the absorption tower washing section 64.

[0067] The absorbent liquid (rich absorbent liquid) that has absorbed carbon dioxide in the absorption tower packing material 61 is stored below the main body 60 of the absorption tower 6. The rich absorbent liquid is sent to the regeneration tower 7 via the rich absorbent liquid line 621 by the pump 622. The rich absorbent liquid is regenerated in the regeneration tower 7 to become lean absorbent liquid, which is then sent back to the absorption tower 6 via the lean absorbent liquid line 721 by the pump 722. The rich absorbent liquid and lean absorbent liquid are heat-exchanged by the heat exchanger 623. Furthermore, a heat exchanger 624 is provided downstream of the heat exchanger 623 in the lean absorbent liquid flow direction (towards the absorption tower 6) of the lean absorbent liquid line 721 to cool the lean absorbent liquid to a predetermined temperature.

[0068] Next, an example of the configuration of the regeneration tower 7 will be described. As shown in Figure 7, the regeneration tower 7 comprises a main body 70, a regeneration tower packing material 71, a regeneration tower washing section 73, and a recirculation drum 74.

[0069] The main body 70 is a cylindrical container extending vertically. The regeneration tower packing material 71 is installed inside the main body 70. The absorbent liquid (rich absorbent liquid) that has absorbed carbon dioxide in the absorption tower 6 is introduced above the regeneration tower packing material 71 through the rich absorbent liquid line 621. As it flows downward through the regeneration tower packing material 71, carbon dioxide is released from the rich absorbent liquid by water vapor. The carbon dioxide gas separated from the rich absorbent liquid flows above the main body 70. The absorbent liquid from which carbon dioxide has been removed (lean absorbent liquid) is stored below the main body 70. This lean absorbent liquid is sucked up by the pump 752 and flows through the lean absorbent liquid circulation channel 751, where it is heated by the reboiler 753 installed in the lean absorbent liquid circulation channel 751 and returned to the main body 70.

[0070] The regeneration tower washing section 73 is supplied with washing water to remove the absorbent liquid contained in the carbon dioxide gas. The carbon dioxide gas from which the absorbent liquid has been removed flows from the top of the regeneration tower 7 through the first discharge channel 741, where the water contained in the carbon dioxide gas is condensed in the condenser 742 and introduced into the reflux drum 74. The reflux drum 74 separates the condensed water generated from the carbon dioxide gas from the carbon dioxide gas itself. The condensed water is stored below the reflux drum 74 and sent back to the regeneration tower washing section 73 as washing water by the pump 743. The carbon dioxide gas separated in the reflux drum 74 is discharged from the top of the reflux drum 74 through the second discharge channel 744 to a recovery tank or the like outside the system.

[0071] (Example of Cooling Tower Configuration 1) Furthermore, the configuration of the cooling tower 5 in this embodiment differs from that of the first embodiment in the configuration of the cooling section 54. In Configuration Example 1 of this embodiment, the cooling section 54 introduces cooling water to the cooling water distribution section 543 from a cooling water supply source located at a higher position than the cooling water distribution section 543. The cooling water supply source is, for example, the chimney tray 645 of the absorption tower 6. One end of the cooling water flow path 541 of the cooling section 54 is connected to the chimney tray 645 of the absorption tower 6. The other end of the cooling water flow path 541 is connected to the cooling water distribution section 543 through an on-off valve 545. Note that the cooling water supply source is not limited to being inside the carbon dioxide recovery system 100, but may also be outside.

[0072] Furthermore, as shown in the example in Figure 7, the cooling water passage 541 may branch into a first cooling water passage 541A connected to the cooling water distribution section 543 and a second cooling water passage 541B connected to the condensate distribution section 53. The first cooling water passage 541A and the second cooling water passage 541B are each provided with on-off valves 545 and 546. The on-off valves 545 and 546 are opened and closed by the control of the cooling tower control unit 56. Similar to the first embodiment, the cooling tower control unit 56 opens the on-off valves 545 and 546 to supply cooling water to the cooling section 54 when the temperature of the exhaust gas G1 exceeds the limit temperature. Note that the on-off valves 545 and 546 may also be manually open and closed from outside the cooling tower 5.

[0073] (Effects of Configuration Example 1) In this configuration, the cooling tower 5 can reuse the wash water from the absorption tower 6, eliminating the need to introduce cooling water from outside the system and reducing the operating costs of the cooling tower 5. Furthermore, the chimney tray 645 of the absorption tower 6 is positioned higher than the cooling water distribution section 543 and the condensate water distribution section 53 of the cooling section 54. Therefore, simply by opening the on-off valves 545 and 546 provided in the cooling water flow path 541, the wash water stored in the chimney tray 645 falls out and is supplied as cooling water to the cooling water distribution section 543 and the condensate water distribution section 53. This eliminates the need for a pump to deliver the cooling water, so even if power is lost due to a power outage, for example, if the on-off valves 545 and 546 are open, cooling water can be supplied to the cooling water distribution section 543 and the temperature of the exhaust gas G1 can be reduced. If power is lost while the on-off valves 545 and 546 are closed, an operator may manually open the on-off valves 545 and 546. This makes it possible to suppress deformation and damage to the cooling tower packing material 51 even in the event of a power outage.

[0074] The other components of the cooling unit 54 are the same as in the first embodiment. That is, the configuration of the cooling water dispersion unit 543 and the second cooling tower packing material 544 of the cooling unit 54 may be any of the configurations shown in Figures 2 to 5.

[0075] (Cooling Tower Configuration Example 2) Figure 8 is a second schematic diagram showing a configuration example of a carbon dioxide recovery device according to the second embodiment of the present disclosure. In Configuration Example 2 of this embodiment, the cooling unit 54 introduces cooling water to the cooling water distribution unit 543 from a cooling water supply source with a higher internal pressure than the cooling tower 5. The cooling water supply source is, for example, the reflux drum 74 of the regeneration tower 7. As shown in the example in Figure 8, one end of the cooling water flow path 541 of the cooling unit 54 is connected to the reflux drum 74 of the regeneration tower 7. The other end of the cooling water flow path 541 is connected to the cooling water distribution unit 543 through an on-off valve 545. Note that the cooling water supply source is not limited to being inside the carbon dioxide recovery system 100, but may be outside.

[0076] Furthermore, similar to the first configuration example, the cooling water channel 541 may be branched into a first cooling water channel 541A connected to the cooling water distribution section 543 and a second cooling water channel 541B connected to the condensate distribution section 53. The cooling tower control unit 56, similar to the first embodiment, opens the on-off valve 545 to supply cooling water to the cooling section 54 when the temperature of the exhaust gas G1 exceeds the limit temperature. Note that the on-off valves 545 and 546 may be manually opened and closed from outside the cooling tower 5.

[0077] (Effects of Configuration Example 2) In this configuration, the cooling tower 5 can reuse the reflux water from the reflux drum 74 of the regeneration tower 7, eliminating the need to introduce cooling water from outside the system and reducing the operating costs of the cooling tower 5. Furthermore, during the operation of the carbon dioxide recovery device 4, the reflux drum 74 of the regeneration tower 7 has a higher internal pressure than the cooling tower 5. Therefore, by simply opening the on-off valves 545 and 546 provided in the cooling water flow path 541, the condensed water stored in the reflux drum 74 is discharged and supplied as cooling water to the cooling water distribution section 543 and the condensed water distribution section 53. This eliminates the need for a pump to deliver the cooling water, so even if power is lost due to a power outage, for example, if the on-off valves 545 and 546 are open, cooling water can be supplied to the cooling water distribution section 543 and the temperature of the exhaust gas G1 can be reduced. If power is lost while the on-off valves 545 and 546 are closed, a worker may manually open the on-off valves 545 and 546. This makes it possible to suppress deformation and damage to the cooling tower packing material 51 even in the event of a power outage.

[0078] The other components of the cooling unit 54 are the same as in the first embodiment. That is, the configuration of the cooling water dispersion unit 543 and the second cooling tower packing material 544 of the cooling unit 54 may be any of the configurations shown in Figures 2 to 5.

[0079] <Computer Configuration> Figure 9 is a schematic block diagram showing the configuration of a control unit computer according to at least one embodiment. The computer 900 comprises a processor 901, a main memory 902, an auxiliary memory 903, and an interface 904.

[0080] The cooling tower control unit 56 of the cooling tower 5 described above is implemented in the computer 900. The operation of the cooling tower control unit 56 described above is stored in auxiliary storage device 903 in the form of a program. The processor 901 reads the program from the auxiliary storage device 903, loads it into the main memory 902, and executes the above processing according to the program. The processor 901 also allocates storage areas in the main memory 902 corresponding to each of the above-mentioned storage units according to the program.

[0081] The program may be for implementing a part of the functions to be performed by the computer 900. For example, the program may perform functions in combination with other programs already stored in the auxiliary storage device 903, or in combination with other programs implemented in other devices. In other embodiments, the computer 900 may be equipped with a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to or instead of the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), FPGA (Field Programmable Gate Array), etc. In this case, some or all of the functions implemented by the processor 901 may be implemented by the integrated circuit.

[0082] Examples of auxiliary storage devices 903 include HDDs (Hard Disk Drives), SSDs (Solid State Drives), magnetic disks, magneto-optical disks, CD-ROMs (Compact Disc Read Only Memory), DVD-ROMs (Digital Versatile Disc Read Only Memory), and semiconductor memory. The auxiliary storage device 903 may be an internal media directly connected to the bus of the computer 900, or it may be an external storage device 910 connected to the computer 900 via an interface 904 or a communication line. Furthermore, if this program is distributed to the computer 900 via a communication line, the computer 900 that receives the distribution may expand the program into the main memory 902 and execute the above processing. In at least one embodiment, the auxiliary storage device 903 is a tangible storage medium that is not temporary.

[0083] As described above, several embodiments relating to this disclosure have been explained, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be carried out in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0084] <Note> The method for protecting the cooling tower, carbon dioxide recovery device, and cooling tower packing material described in the above embodiment can be understood, for example, as follows.

[0085] (1) According to the first embodiment, the cooling tower 5 is a cooling tower 5 for cooling exhaust gas G1, and comprises a condensate circulation section 52 having a resin cooling tower packing material 51 that cools the exhaust gas G1 that flows vertically from bottom to top inside the cooling tower 5, a condensate circulation passage 521 that pumps up condensate stored below the cooling tower 5 with a pump 522 and circulates it to the top of the cooling tower 5, and a heat exchanger 523 that cools the condensate flowing through the condensate circulation passage 521, a condensate distribution section 53 that is connected to the condensate circulation passage 521 above the cooling tower 5 and supplies condensate to the cooling tower packing material 51 from above, and a cooling section 54 having a cooling water distribution section 543 that supplies cooling water to cool the exhaust gas G1 upstream of the cooling tower packing material 51 in the flow direction of the exhaust gas G1.

[0086] In this way, the cooling tower 5 can suppress the flow of high-temperature exhaust gas G1 exceeding the heat resistance temperature into the resin cooling tower packing material 51. As a result, the risk of deformation or damage to the cooling tower packing material 51 is reduced, and the lifespan of the cooling tower packing material 51 can be extended.

[0087] (2) According to the second embodiment, in the cooling tower 5 according to the first embodiment, the cooling water distribution section 543 of the cooling section 54 supplies cooling water inside the exhaust gas introduction channel 50A that introduces exhaust gas G1 into the cooling tower 5.

[0088] In this way, the cooling tower 5 can lower the temperature of the exhaust gas G1 before it flows into the cooling tower 5. Therefore, it is possible to prevent high-temperature exhaust gas G1 exceeding the heat resistance temperature from flowing into the resin cooling tower packing material 51.

[0089] (3) According to the third embodiment, in the cooling tower 5 according to the first embodiment, the cooling water distribution unit 543 of the cooling unit 54 supplies cooling water to the cooling tower packing material 51 from below the cooling tower packing material 51.

[0090] In this way, the cooling tower 5 cools the lower side of the cooling tower packing material 51 with cooling water along with the exhaust gas G1, thereby preventing the exhaust gas G1 and the cooling tower packing material 51 from reaching temperatures that exceed the heat resistance temperature of the cooling tower packing material 51.

[0091] (4) According to the fourth embodiment, in the cooling tower 5 according to any one of the first to third embodiments, the cooling section 54 is located below the cooling tower packing material 51 and further includes a second cooling tower packing material 544 having a higher heat resistance temperature than the cooling tower packing material 51.

[0092] In this way, the cooling tower 5 can lower the temperature of the exhaust gas G1 with the second cooling tower packing material 544, which has a higher heat resistance temperature, before the exhaust gas G1 flows through the cooling tower packing material 51. Therefore, it is possible to suppress the flow of high-temperature exhaust gas G1 that exceeds the heat resistance temperature into the resin cooling tower packing material 51.

[0093] (5) According to the fifth embodiment, in the cooling tower 5 according to the first embodiment, the cooling section 54 is located below the cooling tower packing material 51 and further includes a second cooling tower packing material 544 having a higher heat resistance temperature than the cooling tower packing material 51, and the cooling water distribution section 543 is provided between the cooling tower packing material 51 and the second cooling tower packing material 544 and supplies cooling water to the second cooling tower packing material 544.

[0094] In this way, the cooling tower 5 can more reliably lower the temperature of the exhaust gas G1 before it reaches the cooling tower packing material 51, thanks to the second cooling tower packing material 544 and the cooling water.

[0095] (6) According to the sixth embodiment, in the cooling tower 5 according to any one of the first to fifth embodiments, the cooling section 54 has a cooling water channel 541 that branches off from a position downstream of the heat exchanger 523 in the condensate water circulation channel 521 and introduces a portion of the condensate cooled in the heat exchanger 523 as cooling water into the cooling water distribution section 543.

[0096] By reusing the condensed water from the condensed water circulation section 52 in this manner, the cooling tower 5 does not need to introduce cooling water from outside the system, thereby reducing the operating costs of the cooling tower 5. Furthermore, since the condensed water cooled by the heat exchanger 523 of the condensed water circulation section 52 is used as cooling water, the temperature of the exhaust gas G1 can be effectively reduced.

[0097] (7) According to the seventh embodiment, in the cooling tower 5 according to any one of the first to fifth embodiments, the cooling unit 54 introduces cooling water into the cooling water distribution unit 543 from a cooling water supply source located at a higher position than the cooling water distribution unit 543.

[0098] In this way, the cooling tower 5 can supply cooling water falling from the cooling water supply source located at a higher position to the cooling water distribution section 543 and the condensate distribution section 53 simply by opening the on-off valves 545 and 546 provided in the cooling water passage 541. This eliminates the need for a pump to deliver the cooling water, so that even in the event of a power outage or other power loss, for example, the cooling water distribution section 543 can be supplied with cooling water to lower the temperature of the exhaust gas G1. This helps to suppress deformation and damage to the cooling tower packing material 51 even in the event of a power outage.

[0099] (8) According to the eighth aspect, in the cooling tower 5 according to the seventh aspect, the cooling water supply source is a chimney tray 645 located at a higher position than the cooling water distribution section 543 in an absorption tower 6 provided downstream of the cooling tower 5, and the cooling section 54 has a cooling water channel 541 that introduces the wash water stored in the chimney tray 645 as cooling water into the cooling water distribution section 543.

[0100] In this way, the cooling tower 5 can reuse the wash water from the absorption tower 6, eliminating the need to introduce cooling water from outside the system and reducing the operating costs of the cooling tower 5. Furthermore, the chimney tray 645 of the absorption tower 6 is positioned higher than the cooling water distribution section 543 and the condensate water distribution section 53 of the cooling section 54. Therefore, by simply opening the on-off valves 545 and 546 provided in the cooling water flow path 541, the wash water stored in the chimney tray 645 falls out and is supplied as cooling water to the cooling water distribution section 543 and the condensate water distribution section 53. This eliminates the need for a pump to deliver the cooling water, so even in the event of a power outage or other power loss, for example, the cooling water distribution section 543 can be supplied with cooling water to lower the temperature of the exhaust gas G1. This suppresses deformation and damage to the cooling tower packing material 51 even in the event of a power outage.

[0101] (9) According to the ninth aspect, in a cooling tower 5 according to any one of the first to fifth aspects, the cooling section 54 introduces cooling water into the cooling water distribution section 543 from a cooling water supply source with a higher internal pressure than the cooling tower 5.

[0102] In this way, the cooling tower 5 can supply cooling water, which is sent from the cooling water supply source by the pressure difference, to the cooling water distribution section 543 and the condensate distribution section 53 simply by opening the on-off valves 545 and 546 provided in the cooling water passage 541. This eliminates the need for a pump to send out the cooling water, so that even in the event of a power outage or other power loss, for example, the cooling water distribution section 543 can be supplied with cooling water to lower the temperature of the exhaust gas G1. This suppresses deformation and damage to the cooling tower packing material 51 even in the event of a power outage.

[0103] (10) According to the tenth embodiment, in the cooling tower 5 according to the ninth embodiment, the cooling water supply source is a recirculation drum 74 located downstream of the cooling tower 5, which has a higher internal pressure than the cooling tower 5, and the cooling section 54 is connected to the recirculation drum 74 and has a cooling water channel 541 that introduces the recirculated water stored in the recirculation drum 74 as cooling water to the cooling water distribution section 543.

[0104] In this way, the cooling tower 5 can reuse the reflux water from the reflux drum 74 of the regeneration tower 7, eliminating the need to introduce cooling water from outside the system and reducing the operating costs of the cooling tower 5. Furthermore, while the carbon dioxide recovery device 4 is in operation, the reflux drum 74 of the regeneration tower 7 has a higher internal pressure than the cooling tower 5. Therefore, by simply opening the on-off valves 545 and 546 provided in the cooling water flow path 541, the condensed water stored in the reflux drum 74 is discharged and supplied as cooling water to the cooling water distribution section 543 and the condensed water distribution section 53. This eliminates the need for a pump to deliver the cooling water, so even in the event of a power outage or other power loss, for example, the cooling water distribution section 543 can be supplied with cooling water to lower the temperature of the exhaust gas G1. This suppresses deformation and damage to the cooling tower packing material 51 even in the event of a power outage.

[0105] (11) According to the eleventh embodiment, the cooling tower 5 according to any one of the first to tenth embodiments further comprises a first thermometer 501 that measures the temperature of exhaust gas G1 at the outlet of the exhaust gas introduction channel 50A that introduces exhaust gas G1 into the cooling tower 5, and at least one of second thermometers 502, 503 that measure the temperature of exhaust gas G1 below the cooling tower packing material 51, and a cooling tower control unit 56 that supplies cooling water to the cooling unit 54 when the temperature of exhaust gas G1 is above a limit temperature corresponding to the heat resistance temperature of the cooling tower packing material 51, and stops supplying cooling water to the cooling unit 54 when the temperature of exhaust gas G1 is below the limit temperature.

[0106] In this way, the cooling tower 5 can lower the temperature of the exhaust gas G1 with cooling water when the temperature of the exhaust gas G1 exceeds the limit temperature, and can stop the supply of cooling water when the temperature of the exhaust gas G1 is below the limit temperature, thereby preventing excessive consumption of cooling water and preventing the temperature of the exhaust gas G1 from dropping too low.

[0107] (12) According to the 12th embodiment, in the cooling tower 5 according to the 9th embodiment, the cooling tower 5 is installed in a plant 1 that discharges exhaust gas G1, and the cooling tower control unit 56 stops the operation of the plant 1 when the temperature of the exhaust gas G1 becomes higher than the upper limit temperature which is higher than the limit temperature.

[0108] In this way, even when it is difficult to lower the temperature of the exhaust gas G1 with cooling water alone, the cooling tower 5 can suppress deformation and damage to the cooling tower packing material 51 caused by high-temperature exhaust gas G1 exceeding the limit temperature.

[0109] (13) According to the 13th embodiment, in the cooling tower 5 according to the 11th or 12th embodiment, the second thermometers 502, 503 are provided at least two different horizontal positions below the cooling tower packing material 51.

[0110] In this way, the cooling tower 5 can suppress the failure to detect temperature increases in the exhaust gas G1 even when the temperature of the exhaust gas G1 differs depending on the horizontal position (temperature unevenness occurs).

[0111] (14) According to the 14th embodiment, the carbon dioxide recovery device 4 comprises a cooling tower 5 according to any one of the first to 13 embodiments, an absorption tower 6 that removes carbon dioxide contained in the exhaust gas G1 cooled by the cooling tower 5 by absorbing it into an absorbent liquid, and a regeneration tower 7 that regenerates the absorbent liquid by separating carbon dioxide from the absorbent liquid discharged from the absorption tower 6.

[0112] In this way, the carbon dioxide recovery device 4 can prevent high-temperature exhaust gas G1 exceeding the heat resistance temperature from flowing into the resin cooling tower packing material 51 of the cooling tower 5. As a result, the risk of deformation or damage to the cooling tower packing material 51 is reduced, and the lifespan of the cooling tower packing material 51 can be extended.

[0113] (15) According to the 15th embodiment, a method for protecting a resin cooling tower packing material 51 that cools exhaust gas G1 flowing inside a cooling tower 5, comprising the steps of: pumping up condensed water stored below the cooling tower 5 with a pump 522 and circulating it to the upper part of the cooling tower 5 through a condensed water circulation channel 521, and cooling the condensed water flowing through the condensed water circulation channel 521 with a heat exchanger 523; supplying condensed water to the cooling tower packing material 51 from above the cooling tower packing material 51 with a condensed water distribution unit 53 connected to the condensed water circulation channel 521 above the cooling tower 5; and supplying cooling water to cool the exhaust gas G1 to an upstream side of the cooling tower packing material 51 in the flow direction of the exhaust gas G1.

[0114] According to the above-described embodiment, it is possible to suppress the flow of high-temperature exhaust gas exceeding the heat resistance temperature into the resin-based cooling tower packing material.

[0115] 1. Plant 100 Carbon Dioxide Recovery System 2. Dust Collector 3. Desulfurization Unit 4. Carbon Dioxide Recovery Unit 5. Cooling Tower 50 Main Body 50A Exhaust Gas Inlet Channel 50B Exhaust Gas Outlet Channel 51 Cooling Tower Packing Material 52 Condensed Water Circulation Section 521 Condensed Water Circulation Channel 522 Pump 523 Heat Exchanger 53 Condensed Water Dispersion Section 54 Cooling Section 541 Cooling Water Circulation Channel 542 Cooling Water Control Valve 543 Cooling Water Dispersion Section 544 Second Cooling Tower Packing Material 545 On / Off Valve 546 On / Off Valve 56 Cooling Tower Control Section 6. Absorption Tower 60 Main Body 61 Absorption Tower Packing Material 61A First Absorption Tower Packing Material 61B Second Absorption Tower Packing Material 63 Absorbent Liquid Dispersion Section 63A First Absorbent Liquid Dispersion Section 63B Second Absorbent Liquid Dispersion Section 621 Rich Absorbent Liquid Line 622 Pump 623 Heat exchanger 624 Heat exchanger 625 Absorbent liquid control valve 64 Absorbent tower washing section 641 Wash water circulation channel 642 Pump 643 Heat exchanger 645 Chimney tray 65 Purified gas discharge channel 7 Regeneration tower 74 Reflux drum 721 Lean absorbent liquid line

Claims

1. A cooling tower for cooling exhaust gas, comprising: a resin cooling tower packing material for cooling the exhaust gas flowing vertically from bottom to top inside the cooling tower; a condensate circulation section having a condensate circulation channel for pumping up condensate stored at the bottom of the cooling tower and circulating it to the top of the cooling tower; and a heat exchanger for cooling the condensate flowing through the condensate circulation channel; a condensate distribution section connected to the condensate circulation channel at the top of the cooling tower and supplying the condensate from above the cooling tower packing material to the cooling tower packing material; and a cooling section having a cooling water distribution section that supplies cooling water for cooling the exhaust gas upstream of the cooling tower packing material in the flow direction of the exhaust gas.

2. The cooling water distribution section of the cooling section supplies the cooling water inside the exhaust gas introduction channel for introducing the exhaust gas into the cooling tower, according to claim 1.

3. The cooling water distribution section of the cooling section supplies the cooling water to the cooling tower packing material from below the cooling tower packing material, as described in claim 1.

4. The cooling section is located below the cooling tower packing material and further comprises a second cooling tower packing material having a higher heat resistance temperature than the cooling tower packing material, according to claim 1.

5. The cooling section is located below the cooling tower packing material and further comprises a second cooling tower packing material having a higher heat resistance temperature than the cooling tower packing material, and the cooling water distribution section is provided between the cooling tower packing material and the second cooling tower packing material and supplies cooling water to the second cooling tower packing material, as described in claim 1.

6. The cooling tower according to any one of claims 1 to 5, wherein the cooling section has a cooling water channel that branches off from a position downstream of the heat exchanger in the condensate circulation channel and introduces a portion of the condensate cooled by the heat exchanger as cooling water into the cooling water distribution section.

7. The cooling tower according to any one of claims 1 to 5, wherein the cooling section introduces the cooling water into the cooling water distribution section from a cooling water supply source located at a higher position than the cooling water distribution section.

8. The cooling tower according to claim 7, wherein the cooling water supply source is a chimney tray located at a higher position than the cooling water distribution section in an absorption tower provided downstream of the cooling tower, and the cooling section has a cooling water channel for introducing the wash water stored in the chimney tray as the cooling water into the cooling water distribution section.

9. The cooling section introduces the cooling water into the cooling water distribution section from a cooling water supply source with a higher internal pressure than the cooling tower, according to any one of claims 1 to 5.

10. The cooling tower according to claim 9, wherein the cooling water supply source is a recirculation drum having a higher internal pressure than the cooling tower, in a regeneration tower provided downstream of the cooling tower, and the cooling section is connected to the recirculation drum and has a cooling water channel for introducing the recirculated water stored in the recirculation drum as the cooling water into the cooling water distribution section.

11. A cooling tower according to any one of claims 1 to 5, further comprising: a first thermometer for measuring the temperature of the exhaust gas at the outlet of an exhaust gas introduction channel for introducing the exhaust gas into the cooling tower, and a second thermometer for measuring the temperature of the exhaust gas below the cooling tower packing material; and a cooling tower control unit that causes the cooling unit to supply the cooling water when the temperature of the exhaust gas is above a limiting temperature corresponding to the heat resistance temperature of the cooling tower packing material, and stops the supply of the cooling water to the cooling unit when the temperature of the exhaust gas is below the limiting temperature.

12. The cooling tower according to claim 11, wherein the cooling tower is provided in a plant that discharges the exhaust gas, and the cooling tower control unit stops the operation of the plant when the temperature of the exhaust gas exceeds an upper limit temperature that is higher than the limit temperature.

13. The cooling tower according to claim 11, wherein the second thermometer is provided at least two different horizontal positions below the cooling tower packing material.

14. A carbon dioxide recovery apparatus comprising: a cooling tower according to any one of claims 1 to 5; an absorption tower for removing carbon dioxide contained in the exhaust gas cooled by the cooling tower by absorbing it into an absorbent liquid; and a regeneration tower for regenerating the absorbent liquid by separating the carbon dioxide from the absorbent liquid discharged from the absorption tower.

15. A method for protecting a resin cooling tower packing material that cools exhaust gas flowing inside a cooling tower, comprising the steps of: pumping up condensed water stored at the bottom of the cooling tower and circulating it upward through a condensed water circulation channel, and cooling the condensed water flowing through the condensed water circulation channel with a heat exchanger; supplying the condensed water from above the cooling tower packing material to the cooling tower packing material from a condensed water distribution unit connected to the condensed water circulation channel at the top of the cooling tower; and supplying cooling water to cool the exhaust gas to an upstream side of the cooling tower packing material in the direction of exhaust gas flow.

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