Carbon dioxide recovery facility

Abstract

To provide a carbon dioxide recovery facility which enables an amount of heat provided by an external facility, such as a plant, to be effectively used in a reboiler and can properly heat an absorbent in the reboiler.SOLUTION: A carbon dioxide recovery facility 12 of an embodiment includes: an absorption tower 20 in which a processing object exhaust gas containing carbon dioxide is introduced and carbon dioxide is absorbed by an absorbent containing moisture; a regeneration tower 30 in which carbon dioxide is discharged from the absorbent supplied from the absorption tower 20; and a reboiler 40 which heats a lean liquid 32 of the regeneration tower 30. The carbon dioxide recovery facility 10 includes: a heat storage part 81 which stores an amount of heat for generating steam from the lean liquid 32 in the reboiler 40 and supplying a reboiler heat medium at a reboiler allowable temperature allowed in the reboiler 40 to the reboiler 40; and a heating supply mechanism 70C including a structure for heating the heat storage part 81 and supplying the amount of heat stored in the heat storage part 81 to the reboiler 40.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE EMBODIMENTS An embodiment of the present invention relates to a carbon dioxide capture facility. [Background technology]

[0002] In recent years, carbon dioxide (CO 2 ) emissions are being promoted. In this context, carbon dioxide capture and storage (CCS) technology, which captures and stores carbon dioxide, is attracting attention. Specifically, carbon dioxide capture equipment that uses an absorbent to capture carbon dioxide contained in exhaust gas to be treated (hereinafter referred to as exhaust gas) emitted from thermal power plants, steel plants, waste incineration plants, etc., is being considered.

[0003] In this carbon dioxide recovery system, the flue gas is supplied to an absorption tower. In the absorption tower, the carbon dioxide contained in the flue gas is absorbed by an absorbing liquid containing an amine and water. The flue gas from which the carbon dioxide has been removed is discharged from the absorption tower.

[0004] The absorbing liquid that has absorbed carbon dioxide is supplied to the regenerator. In the regenerator, the absorbing liquid releases carbon dioxide. At this time, the released carbon dioxide is discharged from the regenerator together with steam and separated and recovered. The absorbing liquid that has released carbon dioxide in the regenerator is returned to the absorption tower.

[0005] Here, a reboiler is connected to the regeneration tower. The reboiler heats the absorbing liquid, which is an aqueous amine solution, to a temperature of about 110 to 130° C. A heat medium for heating the absorbing liquid is supplied to the reboiler.

[0006] The temperature of the heat medium introduced into the reboiler is limited to a temperature of 200° C. or less in order to prevent deterioration of the absorbing liquid. That is, the temperature of the heat medium is set within a narrow range in order to keep the temperature at 200° C. or less and to heat the absorbing liquid to the above-mentioned temperature.

[0007] The heat medium introduced into the reboiler is, for example, steam generated in a plant. By appropriately controlling the pressure of the steam, it is possible to utilize the latent heat accompanying the phase change from steam to water during heat exchange between the steam (heat medium) and the absorption liquid in the reboiler. In this way, by using steam, it is possible to maintain the heat source temperature of the reboiler within a narrow range. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 6806833 Summary of the Invention [Problem to be solved by the invention]

[0009] The temperature and flow rate of steam from a plant introduced into the reboiler as a heat medium vary depending on the operating conditions of the plant. Therefore, depending on the operating conditions of the plant, high-temperature steam and low-temperature steam may be mixed and supplied to the reboiler, or steam that has been reduced in pressure or temperature may be supplied to the reboiler. Thus, conventional carbon dioxide capture equipment is not able to effectively utilize the energy of steam generated in plants, etc.

[0010] In addition, the flow rate of steam generated in a plant does not necessarily match the flow rate of steam used in the plant and reboiler. Therefore, for example, when the flow rate of steam used in the reboiler is insufficient, the flow rate of fuel supplied to the plant is increased to increase the flow rate of steam generated.

[0011] On the other hand, when the flow rate of steam generated in a plant or the like is greater than the flow rate of steam used in the plant and in the reboiler, the excess steam is discharged outside the system.

[0012] The problem to be solved by the present invention is to provide carbon dioxide recovery equipment that can effectively utilize the heat provided from an external facility such as a plant in a reboiler and can properly heat the absorption liquid in the reboiler. [Means for solving the problem]

[0013] The carbon dioxide recovery equipment of the embodiment includes an absorption tower into which a carbon dioxide-containing exhaust gas to be treated is introduced and into which the carbon dioxide is absorbed in an absorption liquid containing water, a regeneration tower that releases carbon dioxide from the absorption liquid supplied from the absorption tower, a reboiler that heats the absorption liquid in the regeneration tower to generate steam, a heat storage unit that generates steam from the absorption liquid in the reboiler and stores a heat amount for supplying a reboiler heat medium having a reboiler allowable temperature to the reboiler, and a heat supply mechanism that heats the heat storage unit and supplies the heat amount stored in the heat storage unit to the reboiler. The heat supply mechanism also includes a heat storage unit heat medium supply pipe that supplies a first heat medium, which is an excess heat medium that satisfies the reboiler allowable temperature generated in an external facility, to the heat storage unit, a heat storage unit heat medium discharge pipe that discharges the first heat medium from the heat storage unit, and a circulation pipe that circulates a circulating heat medium that functions as the reboiler heat medium to the heat storage unit and the reboiler.

[0014] When storing heat in the heat storage unit, the first heat medium introduced into the heat storage unit through the heat storage unit heat medium supply pipe provides the heat to the heat storage unit and is discharged from the heat storage unit through the heat storage unit heat medium discharge pipe. When dissipating heat from the heat storage unit, the circulating heat medium introduced into the heat storage unit through the circulation piping removes the heat from the heat storage unit to satisfy the reboiler allowable temperature and is supplied to the reboiler through the circulation piping. [Brief description of the drawings]

[0015] [Figure 1] 1 is a system diagram of a carbon dioxide capture facility according to a first embodiment. [Diagram 2]FIG. 2 is a system diagram of a reboiler heat medium supply mechanism in the carbon dioxide recovery facility of the first embodiment. [Diagram 3] FIG. 4 is a system diagram of a reboiler heat medium supply mechanism of another configuration in the carbon dioxide recovery facility of the first embodiment. [Figure 4] FIG. 10 is a diagram showing a schematic configuration of a heat storage device including a chemical heat storage material in a reboiler heat medium supply mechanism having another configuration in the carbon dioxide recovery facility of the first embodiment. [Diagram 5] FIG. 11 is a system diagram of a reboiler heat medium supply mechanism in a carbon dioxide recovery facility according to a second embodiment. [Figure 6] FIG. 11 is a diagram showing a schematic configuration of a heat storage device having another configuration in the carbon dioxide recovery facility according to the second embodiment. [Figure 7] FIG. 11 is a diagram showing a schematic configuration of a heat storage device having another configuration in the carbon dioxide recovery facility according to the second embodiment. [Figure 8] FIG. 11 is a system diagram of a reboiler heat medium supply mechanism in a carbon dioxide recovery facility according to a third embodiment. [Figure 9] FIG. 13 is a system diagram of a reboiler heat medium supply mechanism in a carbon dioxide recovery facility according to a fourth embodiment. [Figure 10] FIG. 13 is a system diagram of a reboiler heat medium supply mechanism of another configuration in the carbon dioxide recovery facility of the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0017] (First embodiment) Fig. 1 is a system diagram of a carbon dioxide recovery system 10 according to a first embodiment. Fig. 2 is a system diagram of a reboiler heat medium supply mechanism 50A in the carbon dioxide recovery system 10 according to the first embodiment. Note that Fig. 2 mainly shows the configuration of the reboiler heat medium supply mechanism 50A in the carbon dioxide recovery system 10.

[0018] As shown in FIG. 1, the carbon dioxide recovery system 10 includes an absorption tower 20, a regenerator 30, a reboiler 40, and a reboiler heat medium supply mechanism 50A.

[0019] The absorption tower 20 is introduced with exhaust gas (exhaust gas) to be treated that contains carbon dioxide, and absorbs the carbon dioxide in an absorbing liquid containing water. In the following, the exhaust gas to be treated is referred to as exhaust gas. The absorption tower 20 includes an absorption section 21 that brings the exhaust gas into gas-liquid contact with the absorbing liquid that falls and disperses.

[0020] A lean liquid introduction pipe 37 that supplies the absorbing liquid (lean liquid 32 described later) from the regenerator 30 to the absorber 20 is connected to the upper part of the absorber 20. The lean liquid 32 is dispersed from above the absorbing section 21.

[0021] An exhaust gas introduction pipe 24 that introduces exhaust gas into the absorption tower 20 is connected to the lower part of the absorption tower 20. The exhaust gas introduction pipe 24 is connected to the absorption tower 20, for example, at a position between the liquid level of the absorbing liquid that has absorbed carbon dioxide and accumulated at the bottom and the absorption section 21. The exhaust gas introduction pipe 24 is equipped with an exhaust gas blower 24a that pressure-feeds the exhaust gas to the absorption tower 20.

[0022] Exhaust gas is introduced from the bottom to the top of the absorbing section 21, and absorbing liquid is introduced from the top to the bottom of the absorbing section 21. Then, in the absorbing section 21, the exhaust gas and the absorbing liquid are brought into gas-liquid contact, causing carbon dioxide to be absorbed by the absorbing liquid.

[0023] Here, the absorption liquid that has absorbed carbon dioxide in the absorption tower 20 is referred to as rich liquid 23. The rich liquid 23 accumulates at the bottom of the absorption tower 20. The rich liquid 23 accumulates below the absorption section 21. The upper end of the absorption tower 20 is provided with an outlet 22 for discharging the exhaust gas from which carbon dioxide has been removed.

[0024] The exhaust gas introduced into the absorption tower 20 is not particularly limited as long as it is an exhaust gas containing carbon dioxide. Examples of the exhaust gas include exhaust gas discharged from a thermal power plant, a steel plant, a waste incineration plant, and the like.

[0025] The absorbing liquid is preferably an aqueous solution of an amine such as monoethanolamine or diethanolamine. The absorbing liquid is not limited to such types of amine. The absorbing liquid may be an aqueous solution containing one or more types of amine.

[0026] The regeneration tower 30 releases carbon dioxide from the absorption liquid that has absorbed the carbon dioxide supplied from the absorption tower 20. The regeneration tower 30 includes a regeneration section 31 that brings the steam generated in the reboiler 40 into gas-liquid contact with the absorption liquid that has absorbed the carbon dioxide that falls and disperses.

[0027] A rich liquid introduction pipe 25 that supplies the rich liquid 23 from the absorption tower 20 to the regeneration tower 30 is connected to the upper part of the regeneration tower 30. The rich liquid 23 is dispersed from above the regeneration section 31.

[0028] Steam is introduced from the bottom to the top of the regenerator 31, and the rich liquid 23 is introduced from the top to the bottom of the regenerator 31. Then, in the regenerator 31, the steam and the rich liquid 23 are brought into gas-liquid contact to release carbon dioxide from the rich liquid 23. Here, the absorption liquid from which carbon dioxide has been released in the regenerator 30 is referred to as lean liquid 32. The lean liquid 32 accumulates at the bottom of the regenerator 30. The lean liquid 32 accumulates below the regenerator 31.

[0029] The upper end of the regeneration tower 30 is provided with a carbon dioxide outlet 33 for discharging the carbon dioxide released from the rich liquid 23. The carbon dioxide outlet 33 is connected to a gas-liquid separator 35 via a carbon dioxide exhaust pipe 34. The carbon dioxide exhaust pipe 34 is provided with a cooler 36 for condensing water vapor discharged from the carbon dioxide exhaust port 33 together with the carbon dioxide.

[0030] The gas-liquid separator 35 separates the carbon dioxide from the water generated in the cooler 36. The upper end of the gas-liquid separator 35 is provided with a recovery port 35a for recovering carbon dioxide. In addition, the bottom of the gas-liquid separator 35 is provided with a drain pipe 35b for returning the water separated in the gas-liquid separator 35 to the regenerator 30. The drain pipe 35b is connected to the regenerator 30 at a position above the regenerator 31, for example.

[0031] In addition, a reboiler 40 is connected to the regeneration tower 30. The reboiler 40 heats the lean liquid 32 accumulated at the bottom of the regeneration tower 30. The reboiler 40 includes a circulation pipe 41 that introduces the lean liquid 32 from the regeneration tower 30 and returns the heated lean liquid 32 containing steam to the regeneration tower 30.

[0032] In the reboiler 40, the lean liquid 32 is heated by heat exchange between the heat medium supplied from the reboiler heat medium supply mechanism 50A and the lean liquid 32 supplied from the regenerator 30 to generate steam. The lean liquid 32 is heated in the reboiler 40 to, for example, about 110 to 130° C. The reboiler heat medium supply mechanism 50A will be described later.

[0033] By heating the lean liquid 32 to this temperature range, it is possible to generate steam that is brought into gas-liquid contact with the rich liquid 23 in the regenerator 31. In addition, by heating to this temperature range, deterioration of the absorbing liquid can be suppressed.

[0034] Between the bottom of the absorption tower 20 and the top of the regeneration tower 30, a rich liquid introduction pipe 25 is provided to introduce the rich liquid 23 from the absorption tower 20 to the regeneration tower 30. Here, the rich liquid introduction pipe 25 is connected to the regeneration tower 30 at a position above the regeneration section 31 as described above.

[0035] The rich liquid introduction pipe 25 is connected to the regeneration tower 30 through a heat exchanger 26. In addition, the rich liquid introduction pipe 25 is provided with a rich liquid pump 27 that pumps the rich liquid 23 from the absorption tower 20 to the regeneration tower 30.

[0036] In addition, a lean liquid introduction pipe 37 for introducing the lean liquid 32 from the regenerator 30 to the absorber 20 is provided between the bottom of the regenerator 30 and the upper part of the absorber 20. Here, the lean liquid introduction pipe 37 is connected to the absorber 20 at a position above the absorbing section 21 as described above.

[0037] The lean liquid introduction pipe 37 passes through a heat exchanger 26 and is connected to the absorption tower 20. In the heat exchanger 26, the rich liquid 23 flowing through the rich liquid introduction pipe 25 and the lean liquid 32 flowing through the lean liquid introduction pipe 37 exchange heat with each other.

[0038] The lean liquid introduction pipe 37 is provided with a lean liquid pump 38 that pumps the lean liquid 32 from the regenerator 30 to the absorber 20. The lean liquid introduction pipe 37 is also provided with, for example, a cooler 39 that cools the lean liquid 32.

[0039] Here, a description will be given of the operation of the carbon dioxide recovery system 10. The operation of the reboiler heat medium supply mechanism 50A will be described later.

[0040] The exhaust gas introduced into the lower part of the absorption tower 20 from the exhaust gas introduction pipe 24 flows upward through the absorption section 21. The lean liquid 32 introduced into the upper part of the absorption tower 20 from the lean liquid introduction pipe 37 disperses and falls, flowing downward through the absorption section 21. In the absorption section 21, the exhaust gas and the lean liquid 32 come into gas-liquid contact with each other, whereby the carbon dioxide contained in the exhaust gas is absorbed by the lean liquid 32, and the rich liquid 23 is produced.

[0041] The exhaust gas that has come into gas-liquid contact with the lean liquid 32 has carbon dioxide removed therefrom and is discharged from the exhaust port 22 of the absorption tower 20.

[0042] The generated rich liquid 23 is temporarily stored in the bottom of the absorption tower 20. The rich liquid 23 stored in the bottom is introduced into the heat exchanger 26 through the rich liquid inlet pipe 25. In the heat exchanger 26, the rich liquid 23 is heated by heat exchange with the lean liquid 32 flowing through the lean liquid inlet pipe 37. The heated rich liquid 23 is introduced into the regeneration tower 30.

[0043] The lean liquid 32 stored at the bottom of the regeneration tower 30 is introduced into the reboiler 40 through the circulation pipe 41. The lean liquid 32 introduced into the reboiler 40 is heated by heat exchange with the heat medium introduced from the reboiler heat medium supply mechanism 50A. Then, steam (water vapor) is generated from the heated lean liquid 32. At this time, carbon dioxide may also be released from the lean liquid 32.

[0044] The generated steam is supplied together with carbon dioxide to the lower part of the regenerator 30. The steam supplied to the lower part of the regenerator 30 flows upward through the regeneration section 31. On the other hand, the rich liquid 23 introduced from the absorption tower 20 to the regenerator 30 falls in a dispersed manner and flows downward through the regeneration section 31.

[0045] In the regeneration section 31, the rich liquid 23 and the steam are brought into gas-liquid contact, whereby carbon dioxide is released from the rich liquid 23 and the lean liquid 32 is generated. In this manner, the absorbing liquid is regenerated in the regeneration tower 30.

[0046] The generated lean liquid 32 is temporarily stored at the bottom of the regeneration tower 30. The lean liquid 32 stored at the bottom is introduced into the heat exchanger 26 through the lean liquid introduction pipe 37. In the heat exchanger 26, the lean liquid 32 exchanges heat with the rich liquid 23 flowing through the rich liquid introduction pipe 25, and is cooled. The cooled lean liquid 32 is further cooled by the cooler 39, and is introduced into the absorption tower 20. In this manner, the absorption liquid circulates between the absorption tower 20 and the regeneration tower 30.

[0047] Furthermore, the carbon dioxide released from the rich liquid 23 in the regeneration section 31 and the steam that has come into gas-liquid contact with the rich liquid 23 are discharged from a carbon dioxide outlet 33. The carbon dioxide and steam discharged from the carbon dioxide outlet 33 pass through a carbon dioxide exhaust pipe 34 and are introduced into a cooler 36. In the cooler 36, the steam (water vapor) is condensed to become water. The carbon dioxide and water are then introduced into a gas-liquid separator 35 and separated into carbon dioxide and water.

[0048] The carbon dioxide is recovered in a predetermined recovery section through a recovery port 35a. The water is introduced from the gas-liquid separator 35 into the regenerator 30 through a drain pipe 35b.

[0049] Next, the reboiler heat medium supply mechanism 50A will be described.

[0050] The reboiler heat medium supply mechanism 50A has a configuration for supplying a heat medium to the reboiler 40. As shown in FIG. 2, the reboiler heat medium supply mechanism 50A has a reboiler heat medium supply pipe 60, a reboiler heat medium discharge pipe 61, a heat supply mechanism 70A, and a heat storage device 80.

[0051] The reboiler heat medium supply pipe 60 is connected to the reboiler 40 and supplies a reboiler heat medium 62 for heating the absorption liquid (lean liquid 32) to the reboiler 40. The reboiler heat medium discharge pipe 61 is connected to the reboiler 40 and discharges the reboiler heat medium 62 having heated the absorption liquid (lean liquid 32) from the reboiler 40.

[0052] Here, for example, steam (water vapor) generated in a thermal power plant, a steel plant, a waste incineration plant, or the like, in which the carbon dioxide recovery facility 10 is installed, is used as the reboiler heat medium 62. The temperature of the reboiler heat medium 62 supplied to the reboiler 40 is set to, for example, about 130 to 200°C.

[0053] The temperature range permissible as the temperature of the heat medium supplied to the reboiler 40 is referred to as the reboiler permissible temperature. By setting this temperature range, the lean liquid 32 in the reboiler 40 can be heated to the above-mentioned temperature range and deterioration of the absorption liquid can be suppressed.

[0054] For example, when the carbon dioxide recovery facility 10 is installed next to a thermal power plant equipped with a steam turbine, steam extracted from the steam turbine is used as the reboiler heat medium 62. In this case, the reboiler heat medium 62 that has been condensed into water in the reboiler 40 is introduced into a feed water pipe between the condenser and the boiler via a reboiler heat medium discharge pipe 61.

[0055] The heat supply mechanism 70A has a configuration for heating the heat storage section 81 of the heat storage device 80 and supplying the amount of heat stored in the heat storage section 81 to the reboiler 40. As shown in FIG. 2 , the heat supply mechanism 70A has a communication pipe 71, a heat medium discharge pipe 72, and a heat storage section heat medium supply pipe 73.

[0056] The communication pipe 71 communicates between the reboiler heat medium supply pipe 60 and the heat storage section 81. One end of the communication pipe 71 is connected to the reboiler heat medium supply pipe 60, and the other end of the communication pipe 71 is connected to the heat storage section 81. The communication pipe 71 is provided with, for example, a temperature detection section 75 that detects the temperature of the heat medium flowing through the communication pipe 71.

[0057] The heat medium discharge pipe 72 discharges the reboiler heat medium 62 supplied from the reboiler heat medium supply pipe 60 to the heat storage section 81 via the communication piping 71. For example, when the carbon dioxide recovery equipment 10 is installed in a thermal power plant equipped with a steam turbine, the reboiler heat medium 62 condensed into water in the heat storage section 81 is introduced via the heat medium discharge pipe 72 into a water supply pipe between the condenser and the boiler.

[0058] A flow rate control valve 72a is provided in the heat medium discharge pipe 72. In addition, the heat medium discharge pipe 72 is provided with, for example, a temperature detection unit 76 that detects the temperature of the reboiler heat medium 62 discharged from the heat accumulator 80.

[0059] The heat storage section heat medium supply pipe 73 supplies the heat storage section heat medium 74, which has a temperature lower than that of the reboiler heat medium 62, to the heat storage section 81. A flow rate control valve 73a is provided on the heat storage section heat medium supply pipe 73. As the heat storage section heat medium 74, for example, low-temperature steam (water vapor) generated in the above-mentioned plant or the like is used.

[0060] The heat storage device 80 includes a heat storage section 81 that stores the amount of heat used to heat the absorption liquid in the reboiler 40. The heat storage section 81 includes a latent heat storage material or a sensible heat storage material. The heat storage section 81 is configured, for example, by filling a specific container with the heat storage material. The heat storage device 80 is configured by housing the heat storage section 81 in a specific device container.

[0061] The latent heat storage material is a heat storage material that stores heat by utilizing a phase change of a substance. The latent heat storage material is formed, for example, by filling a latent heat storage material into an outer shell (shell) or a container made of resin or the like. For example, a substance that changes phase at 130 to 200°C is used as the latent heat storage material. This temperature range corresponds to the allowable temperature of the reboiler. Here, the latent heat storage material may be heated above the temperature (melting point) at which the phase changes. In this case, for example, sensible heat is stored in the latent heat storage material in a liquid state. The upper limit temperature used as sensible heat storage in the latent heat storage material is 200°C, which corresponds to the upper limit of the allowable temperature of the reboiler.

[0062] By using a substance that changes phase within this temperature range, the temperature of the reboiler heat medium 62 supplied to the reboiler 40 can be set to the reboiler allowable temperature. Note that, in the latent heat storage material, this temperature range is the set heating temperature. Specifically, examples of the latent heat storage material include polyethylene, sugar alcohols such as erythritol and mannitol, and paraffin.

[0063] When a latent heat storage material is used as the heat storage material, the heat storage unit 81 is configured by filling a plurality of latent heat storage materials in a predetermined container. In this case, the latent heat storage material exchanges heat with a fluid flowing through the gaps between the latent heat storage materials, for example.

[0064] Sensible heat storage materials are heat storage materials that store heat due to temperature changes of a substance. Examples of sensible heat storage materials include rocks, concrete, and ceramics. The temperature range used for sensible heat storage is, for example, 130 to 200°C. This temperature range corresponds to the allowable temperature of the reboiler.

[0065] By using this temperature range, the temperature of the reboiler heat medium 62 supplied to the reboiler 40 can be set to the reboiler allowable temperature. Note that in the latent heat storage material, this temperature range is the set heating temperature.

[0066] When a sensible heat storage material is used as the heat storage material, the heat storage unit 81 is configured by filling a plurality of sensible heat storage materials in a predetermined container. In this case, the sensible heat storage material exchanges heat with a fluid flowing through the gaps between the sensible heat storage materials, for example.

[0067] Next, the operation of the reboiler heat medium supply mechanism 50A will be described.

[0068] First, the operation of storing heat in the heat storage device 80 will be described.

[0069] When heat is stored in the heat storage device 80, the conditions of the reboiler heat medium 62 supplied to the reboiler heat medium supply pipe 60 are as follows.

[0070] The temperature of the reboiler heat medium 62 is the reboiler allowable temperature. In addition, in the supply source of the reboiler heat medium 62, the reboiler heat medium 62 can be supplied to the reboiler heat medium supply pipe 60 at a flow rate equal to or greater than the flow rate required by the reboiler 40. That is, in a plant or the like that is the supply source of the reboiler heat medium 62, for example, when an excess heat medium is generated due to high load operation, the heat storage process is performed.

[0071] When storing heat in the heat storage device 80, the flow rate control valve 72a is opened and the flow rate control valve 73a is closed. A part of the reboiler heat medium 62 flowing through the reboiler heat medium supply pipe 60 is introduced into the heat storage section 81 of the heat storage device 80 through the communication pipe 71. At this time, the reboiler heat medium 62 that exceeds the set flow rate of the reboiler heat medium 62 supplied to the reboiler 40 is introduced into the heat storage section 81.

[0072] The reboiler heat medium 62 supplied to the reboiler 40 through the reboiler heat medium supply pipe 60 heats the lean liquid 32 flowing through the circulation pipe 41 in the reboiler 40. The reboiler heat medium 62 having heated the lean liquid 32 is discharged through the reboiler heat medium discharge pipe 61.

[0073] The reboiler heat medium 62 introduced into the heat storage section 81 flows between the heat storage material filled in the heat storage section 81 and provides heat to the heat storage material. As a result, the heat storage section 81 stores the heat.

[0074] The reboiler heat medium 62 that has given heat to the heat storage material is condensed into water and discharged from the heat medium discharge pipe 72 .

[0075] In this manner, in the process of storing heat in the heat storage section 81, if the temperature of the reboiler heat medium 62 detected by the temperature detection section 76 is equal to the temperature of the reboiler heat medium 62 introduced into the heat storage section 81 via the communication pipe 71, the flow rate control valve 72a is closed. Specifically, for example, if the temperature of the reboiler heat medium 62 detected by the temperature detection section 76 is equal to the temperature of the reboiler heat medium 62 detected by the temperature detection section 75, the flow rate control valve 72a is closed. In this case, it means that the amount of heat stored in the heat storage section 81 has exceeded the heat storage upper limit heat amount.

[0076] Next, the operation of the heat storage device 80 when dissipating heat will be described.

[0077] When heat is dissipated in the heat accumulator 80, the conditions of the reboiler heat medium 62 supplied to the reboiler heat medium supply pipe 60 are as follows.

[0078] The temperature of the reboiler heat medium 62 is the reboiler allowable temperature. On the other hand, in the supply source of the reboiler heat medium 62, the flow rate required by the reboiler 40 cannot be supplied to the reboiler heat medium supply pipe 60. That is, in a plant or the like that is the supply source of the reboiler heat medium 62, for example, when the supply amount of the heat medium decreases due to low load operation, the heat dissipation process is performed.

[0079] When heat is released in the heat storage device 80, the flow rate control valve 72a is closed and the flow rate control valve 73a is opened. The heat storage section heat medium 74 is introduced into the heat storage section 81 from the heat storage section heat medium supply pipe 73. The flow rate of the heat storage section heat medium 74 introduced into the heat storage section 81 is adjusted by the flow rate control valve 73a so as to compensate for the shortage of the flow rate of the reboiler heat medium 62.

[0080] The heat storage section heat medium 74 introduced into the heat storage section 81 flows between the heat storage material filled in the heat storage section 81, removes heat from the heat storage material, and is heated. At this time, the heat storage section heat medium 74 is heated to a reboiler allowable temperature.

[0081] In the process of releasing heat from the heat storage section 81, when the temperature of the heat storage section heat medium 74 detected by the temperature detection section 75 falls below a lower threshold, the flow rate adjustment valve 73a is closed. When the temperature of the heat storage section heat medium 74 discharged from the heat storage section 81 falls below the lower threshold, it means that the amount of heat stored in the heat storage section 81 falls below the heat storage lower limit heat amount. When it falls below the heat storage lower limit heat amount, it means that the amount of heat required to heat the heat storage section heat medium 74 to the reboiler allowable temperature is not stored in the heat storage section 81.

[0082] Here, the lower threshold value is set to, for example, 130° C. This value is the lower limit of the allowable reboiler temperature.

[0083] The heated heat storage section heat medium 74 passes through the communication pipe 71 and is introduced into the reboiler heat medium supply pipe 60. Then, the heat storage section heat medium 74 and the reboiler heat medium 62 are mixed in the reboiler heat medium supply pipe 60, and the mixed heat medium is supplied to the reboiler 40 at an optimal flow rate.

[0084] The mixed heat medium supplied to the reboiler 40 heats the absorbing liquid flowing through the circulation pipe 41 in the reboiler 40. The mixed heat medium having heated the absorbing liquid is discharged through the reboiler heat medium discharge pipe 61.

[0085] In the above-described operation of the reboiler heat medium supply mechanism 50A, the control of the flow rate control valves 72a, 73a, etc. based on the detection signals of the temperature detection units 75, 76 may be performed via a control device, for example. This also applies to the following embodiments.

[0086] According to the carbon dioxide recovery equipment 10 of the first embodiment described above, when an excess of heat medium is generated due to high load operation or the like in a plant or the like that is a supply source of the reboiler heat medium 62, the heat quantity of the excess heat medium can be stored in the heat storage device 80. Even when the supply amount of the heat medium is reduced due to low load operation of the plant or the like, the reduced supply amount of the heat medium can be compensated for by using the heat quantity stored in the heat storage device 80.

[0087] In this way, in the carbon dioxide recovery system 10, surplus heat generated in an external facility such as a plant can be effectively utilized in the reboiler 40. In addition, even if a load fluctuation occurs in an external facility such as a plant that is a supply source of the reboiler heat medium 62, the absorption liquid can be appropriately heated in the reboiler 40.

[0088] Furthermore, by providing the reboiler heat medium supply mechanism 50A, the flow rate of the reboiler heat medium 62 supplied to the reboiler 40 can be adjusted to an appropriate flow rate.

[0089] Here, the configuration of the reboiler heat medium supply mechanism 50A in the carbon dioxide recovery facility 10 is not limited to the configuration shown in FIG.

[0090] FIG. 3 is a system diagram of a reboiler heat medium supply mechanism 50A having another configuration in the carbon dioxide recovery plant 10 according to the first embodiment.

[0091] 3, the reboiler heat medium supply mechanism 50A may include a bypass pipe 85 that communicates between the heat storage section heat medium supply pipe 73 and the reboiler heat medium supply pipe 60. The bypass pipe 85 can supply the heat storage section heat medium 74 from the heat storage section heat medium supply pipe 73 to the reboiler heat medium supply pipe 60.

[0092] One end of the bypass pipe 85 is connected to the heat storage section heat medium supply pipe 73 upstream of the position where the flow rate control valve 73a is provided. The other end of the bypass pipe 85 is connected to the reboiler heat medium supply pipe 60 on the reboiler 40 side of the position where the bypass pipe 85 is connected to the communication pipe 71.

[0093] A flow rate control valve 85a is provided in the bypass pipe 85. A temperature detection unit 63 that detects the temperature of the heat medium supplied to the reboiler 40 is provided in the reboiler heat medium supply pipe 60 on the reboiler 40 side from the position where the reboiler heat medium supply pipe 60 is connected to the communication pipe 71.

[0094] In a reboiler heat medium supply mechanism 50A having another configuration, the reboiler heat medium supply pipe 60 is supplied with a reboiler heat medium 62 having a temperature exceeding the reboiler allowable temperature, for example.

[0095] In this configuration, the heat storage unit 81 may include a chemical heat storage material in addition to the latent heat storage material and sensible heat storage material described above. As shown in Fig. 3, when a bypass pipe 85 is provided, heat is stored in a temperature range exceeding the aforementioned usable temperature range (130 to 200°C) even when a latent heat storage material and a sensible heat storage material are used.

[0096] Chemical heat storage materials are heat storage materials that can store and release heat by utilizing the heat of chemical reaction that occurs when the reaction medium and the heat storage material come into contact. Chemical heat storage materials use reversible endothermic and exothermic reactions to store and release heat. For example, CaO / H 2 O-based chemical heat storage material, MgO / H 2 Examples of the chemical heat storage material include O-based chemical heat storage materials. Note that the chemical heat storage material is not limited to these, and any chemical heat storage material that can store and release heat by utilizing a reversible endothermic reaction and exothermic reaction may be used.

[0097] CaO / H 2 When storing heat in O-based chemical heat storage materials, Ca(OH) 2 In other words, Ca(OH) 2The heat storage material in the state of Ca(OH) is heated. 2 CaO and H 2 Heat is stored through a dehydration reaction that separates 1H into 2H.

[0098] At this time, the heat storage material is heated so that its temperature becomes 400 to 500°C. By heating the heat storage material to this temperature range, the dehydration reaction is promoted. CaO / H 2 In the O-based chemical heat storage material, this temperature range is the set heating temperature.

[0099] On the other hand, when dissipating heat, water or steam is supplied to the heat storage material in the CaO state, which causes a hydration reaction in which the water or steam combines with CaO to dissipate heat.

[0100] MgO / H 2 When storing heat in an O-based chemical heat storage material, Mg(OH) 2 In other words, Mg(OH) 2 The heat storage material in this state is heated. The resulting Mg(OH) 2 MgO and H 2 Heat is stored through a dehydration reaction that separates 1H into 2H.

[0101] At this time, the heat storage material is heated so that its temperature becomes 200 to 400°C. By heating the heat storage material to this temperature range, the dehydration reaction is promoted. MgO / H 2 In the O-based chemical heat storage material, this temperature range is the set heating temperature.

[0102] On the other hand, when dissipating heat, water or steam is supplied to the heat storage material in the MgO state, which causes a hydration reaction in which the water or steam combines with the MgO to dissipate heat.

[0103] Here, FIG. 4 is a diagram showing a schematic configuration of a heat storage device 80 equipped with a chemical heat storage material in a reboiler heat medium supply mechanism 50A having another configuration in the carbon dioxide recovery system 10 of the first embodiment. Here, CaO / H 2 O system and MgO / H2 An example of using an O-based chemical heat storage material is given below.

[0104] 4, a heat storage unit 81, in which a container 88 is filled with a chemical heat storage material 87, is accommodated in an equipment container 86 of a heat storage device 80. A heat exchange pipe 84 is arranged in a serpentine manner in the heat storage unit 81. One end of the heat exchange pipe 84 is connected to the communication pipe 71. The other end of the heat exchange pipe 84 is connected to the heat medium discharge pipe 72 and the heat storage unit heat medium supply pipe 73.

[0105] A water supply pipe 82 that supplies water or steam to the heat storage unit 81 is connected to one side of the container 88. For example, a drain pipe 83 that drains water from the heat storage unit 81 is connected to the other side of the container 88 that faces the one side.

[0106] The water generated by the above-mentioned dehydration reaction is discharged to the outside through a drain pipe 83. In addition, water or steam used in the above-mentioned hydration reaction is supplied through a water supply pipe .

[0107] When a chemical heat storage material is used, if no chemical change occurs, heat can be released when necessary. That is, the chemical heat storage material can maintain a heat storage state for a long period of time. In addition, a cartridge equipped with a chemical heat storage material that has been put into a heat storage state by another heat source can be attached to the heat storage device 80 and used.

[0108] In the heat storage operation in the heat storage device 80 using the chemical heat storage material, a part of the reboiler heat medium 62 introduced into the heat exchange pipe 84 through the communication pipe 71 is Ca(OH) 2 or Mg(OH) 2 The heat storage material in this state is heated. Water produced by the dehydration reaction that occurs during this process is discharged from the drain pipe 83. Note that no water is supplied from the water supply pipe 82 during this process.

[0109] In addition, when a chemical heat storage material is used, the temperature of the reboiler heat medium 62 introduced into the reboiler heat medium supply pipe 60 is set to a temperature that causes a dehydration reaction in the chemical heat storage material. Therefore, the temperature of the reboiler heat medium 62 introduced into the reboiler heat medium supply pipe 60 exceeds the reboiler allowable temperature.

[0110] Therefore, the flow rate control valve 85a of the bypass pipe 85 is adjusted based on the temperature of the heat medium supplied to the reboiler 40 detected by the temperature detection unit 63. By adjusting the flow rate control valve 85a, the flow rate of the heat storage section heat medium 74 introduced into the reboiler heat medium supply pipe 60 via the bypass pipe 85 is adjusted.

[0111] Then, the heat storage section heat medium 74 having a temperature lower than that of the reboiler heat medium 62 is introduced into the reboiler heat medium supply pipe 60 via the bypass pipe 85. As a result, a mixed heat medium in which the high-temperature reboiler heat medium 62 and the low-temperature heat storage section heat medium 74 are mixed is supplied to the reboiler 40. The temperature of this mixed heat medium is adjusted to the reboiler allowable temperature and supplied to the reboiler 40.

[0112] In this manner, in the process of storing heat in the heat storage section 81, if the temperature of the reboiler heat medium 62 detected by the temperature detection section 76 is equal to the temperature of the reboiler heat medium 62 introduced into the heat storage section 81 via the communication pipe 71, the flow rate control valve 72a is closed. Specifically, for example, if the temperature of the reboiler heat medium 62 detected by the temperature detection section 76 is equal to the temperature of the reboiler heat medium 62 detected by the temperature detection section 75, the flow rate control valve 72a is closed. In this case, it means that the amount of heat stored in the heat storage section 81 has exceeded the heat storage upper limit heat amount.

[0113] On the other hand, in the heat dissipation action in the heat storage device 80 using the chemical heat storage material, water or water vapor is supplied to the heat storage material in the CaO or MgO state from the water supply pipe 82. This causes a hydration reaction and the heat storage material dissipates heat.

[0114] The heat storage section heat medium 74 introduced into the heat exchange piping 84 via the heat storage section heat medium supply pipe 73 is heated by heat radiation from the heat storage material. At this time, if the temperature of the heat storage section heat medium 74 introduced into the communication piping 71 is higher than the reboiler allowable temperature, the flow rate control valve 85a of the bypass pipe 85 is adjusted based on the temperature of the heat medium supplied to the reboiler 40 detected by the temperature detection unit 63.

[0115] Then, the heat storage section heat medium 74 having a temperature lower than that of the heat storage section heat medium 74 heated in the heat storage section 81 is introduced into the reboiler heat medium supply pipe 60 via the bypass pipe 85. As a result, a mixed heat medium in which the high-temperature heat storage section heat medium 74 and the low-temperature heat storage section heat medium 74 are mixed is supplied to the reboiler 40. The temperature of this mixed heat medium is adjusted to the reboiler allowable temperature and supplied to the reboiler 40.

[0116] In the process of releasing the heat quantity from the heat storage section 81, when the temperature of the heat storage section heat medium 74 detected by the temperature detection section 75 falls below a lower threshold, for example, the flow rate adjustment valve 73a is closed. When the temperature of the heat storage section heat medium 74 discharged from the heat storage section 81 falls below the lower threshold, it means that the heat quantity stored in the heat storage section 81 falls below the heat storage lower limit heat quantity. When it falls below the heat storage lower limit heat quantity, it is in a state where the heat quantity for heating the heat storage section heat medium 74 to the reboiler allowable temperature is not stored in the heat storage section 81. The lower limit threshold in the release process is as described above.

[0117] In the process of releasing heat from the heat storage section 81, when the temperature of the heat storage section heat medium 74 discharged from the heat storage section 81 falls below the lower limit threshold and the flow rate control valve 73a is closed, the temperature of the reboiler heat medium 62 supplied to the reboiler 40 is adjusted by the flow rate control valve 85a of the bypass pipe 85 based on the temperature detected by the temperature detection section 63. Note that when the flow rate control valve 73a is closed, the flow rate control valve 72a may be opened to switch to the heat storage process.

[0118] Note that, although the example described here mainly concerns the case where a chemical heat storage material is used, the adjustment action of the flow control valve 85a based on the temperature detected by the temperature detection unit 63 is the same when the aforementioned latent heat storage material or sensible heat storage material is used.

[0119] As described above, by providing the bypass pipe 85, even if the temperature of the reboiler heat medium 62 supplied to the reboiler heat medium supply pipe 60 exceeds the reboiler allowable temperature, the heat medium at the reboiler allowable temperature can be supplied to the reboiler 40. In other words, by providing the bypass pipe 85, it becomes possible to adjust the temperature of the reboiler heat medium 62 supplied to the reboiler 40 based on the temperature of the heat medium detected by the temperature detection unit 63.

[0120] (Second embodiment) 5 is a system diagram of a reboiler heat medium supply mechanism 50B in the carbon dioxide recovery equipment 11 of the second embodiment. Note that in the following embodiments, the same components as those in the carbon dioxide recovery equipment 10 of the first embodiment are denoted by the same reference numerals, and duplicated explanations will be omitted or simplified.

[0121] The carbon dioxide recovery equipment 11 of the second embodiment has the same configuration as the carbon dioxide recovery equipment 10 of the first embodiment, except for the reboiler heat medium supply mechanism 50B. Therefore, the configuration of the reboiler heat medium supply mechanism 50B will be mainly described here.

[0122] The reboiler heat medium supply mechanism 50B has a configuration for supplying a heat medium to the reboiler 40. As shown in FIG. 5 , the reboiler heat medium supply mechanism 50B has a heat storage device 80, a heat supply mechanism 70B, a reboiler heat medium discharge pipe 61, and a bypass pipe 100.

[0123] The heat storage unit 81 of the heat storage device 80 includes a latent heat storage material, a sensible heat storage material, or a chemical heat storage material. The configuration of each heat storage material is as described above.

[0124] The heat supply mechanism 70B has a configuration for heating the heat storage section 81 of the heat storage device 80 and supplying the amount of heat stored in the heat storage section 81 to the reboiler 40. As shown in Fig. 5, the heat supply mechanism 70B has a high-temperature heat medium introduction pipe 90, a low-temperature heat medium introduction pipe 91, a heat storage section heat medium supply pipe 92, and a reboiler heat medium supply pipe 93.

[0125] The high-temperature heat medium introduction pipe 90 introduces a high-temperature heat medium to be supplied to the reboiler 40. For example, steam (water vapor) generated in an external facility such as a plant is used as the high-temperature heat medium. The temperature of the high-temperature heat medium is higher than the reboiler allowable temperature. Specifically, the temperature of the high-temperature heat medium is, for example, a temperature at which the heat storage material can be heated to the set temperature of the heat storage material or a temperature higher than that. That is, in the second embodiment, even when a latent heat storage material or a sensible heat storage material is used, heat may be stored in a temperature range exceeding the above-mentioned utilization temperature range (130 to 200°C). The high-temperature heat medium introduction pipe 90 functions as a first heat medium introduction pipe.

[0126] The low-temperature heat medium introduction pipe 91 introduces a low-temperature heat medium having a temperature lower than that of the high-temperature heat medium introduced into the high-temperature heat medium introduction pipe 90. For example, steam (water vapor) generated in an external facility such as a plant is used as the low-temperature heat medium. The temperature of the low-temperature heat medium is lower than the allowable temperature of the reboiler.

[0127] The low-temperature heat medium introduction pipe 91 is connected to the high-temperature heat medium introduction pipe 90. The low-temperature heat medium introduction pipe 91 is equipped with a flow rate control valve 91a that adjusts the flow rate of the low-temperature heat medium. The low-temperature heat medium introduction pipe 91 functions as a second heat medium introduction pipe.

[0128] Here, the temperature of the low-temperature heat transfer medium is set to a temperature that can be adjusted to the reboiler allowable temperature by mixing the high-temperature heat transfer medium and the low-temperature heat transfer medium within a predetermined flow rate range. Note that the predetermined flow rate range is the set flow rate range of the reboiler heat transfer medium 62 supplied to the reboiler 40.

[0129] The heat storage section heat medium supply pipe 92 supplies the heat medium introduced into the high-temperature heat medium introduction pipe 90 and the low-temperature heat medium introduction pipe 91 to the heat storage section 81 of the heat storage device 80. The heat storage section heat medium supply pipe 92 is arranged downstream from the connection between the low-temperature heat medium introduction pipe 91 and the heat storage section heat medium supply pipe 92, and is connected to the heat storage section 81.

[0130] The heat storage unit heat medium supply pipe 92 supplies a high-temperature heat medium, a low-temperature heat medium, or a mixed heat medium of a high-temperature heat medium and a low-temperature heat medium to the heat storage unit 81. The heat storage unit heat medium supply pipe 92 is provided with a flow rate adjustment valve 92a that adjusts the flow rate of the heat medium.

[0131] The reboiler heat medium supply pipe 93 supplies the reboiler heat medium 62 discharged from the heat storage section 81 to the reboiler 40. The reboiler heat medium discharged from the heat storage section 81 is a heat medium that is supplied to the heat storage section 81 by the heat storage section heat medium supply pipe 92 and has exchanged heat with the heat storage section 81. The reboiler heat medium supply pipe 93 supplies the reboiler heat medium 62 that heats the absorption liquid (lean liquid 32) in the reboiler 40 to the reboiler 40. The reboiler heat medium supply pipe 93 is provided between the heat storage section 81 and the reboiler 40.

[0132] The reboiler heat medium supply pipe 93 is provided with a temperature detection unit 94 that detects the temperature of the heat medium supplied to the reboiler 40. The temperature detection unit 94 is provided on the reboiler heat medium supply pipe 93 closer to the reboiler 40 than the connecting part that connects to the bypass pipe 100.

[0133] Further, the reboiler heat medium supply pipe 93 is provided with a temperature detection unit 95 that detects the temperature of the heat medium discharged from the heat storage section 81. The temperature detection unit 95 is provided on the reboiler heat medium supply pipe 93 closer to the heat storage device 80 than the connecting part that connects to the bypass pipe 100.

[0134] The reboiler heat medium discharge pipe 61 provided in the reboiler heat medium supply mechanism 50B has the same configuration as in the first embodiment.

[0135] The bypass pipe 100 supplies the heat medium from the heat storage section heat medium supply pipe 92 to the reboiler heat medium supply pipe 93. The bypass pipe 100 is provided so as to bypass the heat storage device 80 and communicate between the heat storage section heat medium supply pipe 92 and the reboiler heat medium supply pipe 93. The bypass pipe 100 is provided with a flow rate control valve 100a that adjusts the flow rate of the heat medium.

[0136] Next, the operation of the reboiler heat medium supply mechanism 50B will be described.

[0137] Here, at the start of operation, it is preferable that a predetermined amount of heat is stored in the heat storage material of the heat storage section 81 of the heat storage device 80. Hereinafter, this state is referred to as the initial state.

[0138] In the case of a latent heat storage material, the initial state is, for example, a state in which the melting point of the latent heat storage material is reached, and is, for example, a state in which a solid phase and a liquid phase are mixed.

[0139] In the case of a sensible heat storage material, the initial state is, for example, a state in which the sensible heat storage material is heated to a reboiler allowable temperature.

[0140] In the case of a chemical heat storage material, the initial state is, for example, a state in which the chemical heat storage material in a state where heat is stored by a dehydration reaction and the chemical heat storage material in a state where heat is released by a hydration reaction are mixed in equal amounts. CaO / H 2 In the O-based chemical heat storage material, Ca(OH) 2 An example is a mixture of equal amounts of MgO / H 2 In the O-based chemical heat storage material, Mg(OH) 2 An example is a mixture of equal amounts of MgO.

[0141] By setting the heat storage section 81 in the above-mentioned initial state, both the heat storage process and the heat release process can be executed.

[0142] Here, in the case where a latent heat storage material or a sensible heat storage material is used, the operation when changing the state in which no heat is stored in the heat storage material to the initial state will be described.

[0143] The flow rate control valve 91a is adjusted to adjust the flow rate of the low-temperature heat medium flowing through the heat storage section heat medium supply pipe 92. Then, in the heat storage section heat medium supply pipe 92, the temperature of the mixed heat medium of the high-temperature heat medium and the low-temperature heat medium introduced from the high-temperature heat medium introduction pipe 90 is adjusted to a predetermined temperature. The temperature of the mixed heat medium is adjusted to, for example, a temperature higher than the reboiler allowable temperature.

[0144] A part of the mixed heat medium is supplied from the heat storage section heat medium supply pipe 92 to the heat storage section 81. The heat storage section 81 is heated by the supplied mixed heat medium and stores the heat. The mixed heat medium from which the heat has been removed by the heat storage section 81 is discharged from the heat storage section 81 and introduced into the reboiler heat medium supply pipe 93. At this time, the temperature of the mixed heat medium is lower than the reboiler allowable temperature.

[0145] The remainder of the mixed heat transfer medium is introduced into the reboiler heat transfer medium supply pipe 93 via the bypass pipe 100 .

[0146] The mixed heat medium discharged from the heat storage section 81 and the mixed heat medium introduced through the bypass pipe 100 are mixed in the reboiler heat medium supply pipe 93 and supplied to the reboiler 40 as the reboiler heat medium 62. Here, the flow rate control valve 92a and the flow rate control valve 100a are adjusted based on the temperature of the heat medium detected by the temperature detection section 94 so that the temperature of the reboiler heat medium 62 becomes the reboiler allowable temperature.

[0147] Then, when it is determined that the temperature of the mixed heat medium discharged from the heat storage section 81 has reached a predetermined temperature based on the temperature of the heat medium detected by the temperature detection section 95, the action of returning to the initial state is stopped.

[0148] The predetermined temperature at which the action is stopped to return to the initial state is, for example, a temperature equal to the melting point in the case of a latent heat storage material, and a reboiler allowable temperature in the case of a sensible heat storage material.

[0149] Through this process, the latent heat storage material or sensible heat storage material of the heat storage section 81 returns to its initial state. From this initial state, the heat storage process or heat release process is carried out.

[0150] Next, the operation of storing heat in the heat storage device 80 will be described.

[0151] Here, the heat storage action will be described separately for the case where a heat medium having a reboiler allowable temperature is introduced into the heat storage section 81, and the case where a heat medium having a temperature exceeding the reboiler allowable temperature is introduced into the heat storage section 81.

[0152] First, the case where a heat medium having a reboiler allowable temperature is introduced into the heat storage section 81 will be described.

[0153] When storing heat, the flow rate regulating valve 100a is closed. That is, the mixed heat medium from the heat storage section heat medium supply pipe 92 does not flow through the bypass pipe 100.

[0154] When storing heat, the flow rate of the low-temperature heat medium introduced from the low-temperature heat medium introduction pipe 91 to the heat storage section heat medium supply pipe 92 is adjusted by the flow rate adjustment valve 91a. For example, the flow rate of the low-temperature heat medium introduced from the low-temperature heat medium introduction pipe 91 to the heat storage section heat medium supply pipe 92 is adjusted to be less than the flow rate of the high-temperature heat medium introduced from the high-temperature heat medium introduction pipe 90 to the heat storage section heat medium supply pipe 92. Specifically, the flow rate adjustment valve 91a is adjusted so that the temperature of the heat medium supplied from the heat storage section heat medium supply pipe 92 to the heat storage section 81 becomes the reboiler allowable temperature. In this case, the temperature of the heat medium supplied from the heat storage section heat medium supply pipe 92 to the heat storage section 81 corresponds to the set heating temperature of the heat storage material of the heat storage section 81.

[0155] When the temperature of the high-temperature heat medium from the high-temperature heat medium inlet pipe 90 is the reboiler allowable temperature, all the heat medium introduced into the heat storage section heat medium supply pipe 92 may be the high-temperature heat medium from the high-temperature heat medium inlet pipe 90. In this case, the flow rate control valve 91a is closed.

[0156] Here, an example of a situation in which the heat storage process is performed is when an excess of high-temperature heat medium is generated during high-load operation in a plant or the like.

[0157] The heat medium (mixed heat medium) supplied to the heat storage section 81 via the heat storage section heat medium supply pipe 92 heats the heat storage material. This causes the heat storage material to store heat. The heat medium (mixed heat medium) discharged from the heat storage section 81 is supplied to the reboiler 40 via the reboiler heat medium supply pipe 93 as the reboiler heat medium 62. Note that since the heat storage section 81 is in an initial state before entering the heat storage process, the temperature of the heat medium (mixed heat medium) discharged from the heat storage section 81 is the reboiler allowable temperature. Also, the flow rate of the heat medium (mixed heat medium) introduced into the reboiler heat medium supply pipe 93 is adjusted to the set flow rate of the reboiler 40.

[0158] In this way, in the process of storing heat in the heat storage unit 81, if the temperature of the heat medium (mixed heat medium) detected by the temperature detection unit 95 is equal to the temperature of the heat medium (mixed heat medium) introduced into the heat storage unit 81 via the heat storage unit heat medium supply pipe 92, for example, the flow rate adjustment valve 92a is closed and the flow rate adjustment valve 100a is opened. In this case, it means that the amount of heat stored in the heat storage unit 81 has exceeded the heat storage upper limit heat amount.

[0159] Then, the heat medium (mixed heat medium) is introduced into the reboiler heat medium supply pipe 93 via the bypass pipe 100. At this time, the flow rate control valve 91a adjusts the temperature of the reboiler heat medium 62 to the reboiler allowable temperature based on the temperature of the heat medium detected by the temperature detection unit 94. Also, the flow rate control valve 100a adjusts the flow rate of the heat medium (mixed heat medium) introduced into the reboiler heat medium supply pipe 93 to the set flow rate of the reboiler 40.

[0160] Next, a case where a heat medium having a temperature exceeding the reboiler allowable temperature is introduced into the heat storage section 81 will be described.

[0161] When storing heat, the flow rate of the low-temperature heat medium introduced from the low-temperature heat medium introduction pipe 91 to the heat storage section heat medium supply pipe 92 is adjusted by the flow rate control valve 91a. For example, the flow rate of the low-temperature heat medium introduced from the low-temperature heat medium introduction pipe 91 to the heat storage section heat medium supply pipe 92 is adjusted to be less than the flow rate of the high-temperature heat medium introduced from the high-temperature heat medium introduction pipe 90 to the heat storage section heat medium supply pipe 92. Specifically, the flow rate control valve 91a is adjusted so that the temperature of the heat medium supplied from the heat storage section heat medium supply pipe 92 to the heat storage section 81 is higher than the reboiler allowable temperature.

[0162] When storing heat, all the heat medium introduced into the heat storage section heat medium supply pipe 92 may be the high temperature heat medium from the high temperature heat medium introduction pipe 90. In this case, the flow rate adjustment valve 91a is closed.

[0163] Here, when a heat medium having a temperature exceeding the reboiler allowable temperature is introduced into the heat storage section 81, the heat medium (mixed heat medium) is introduced into the reboiler heat medium supply pipe 93 via the bypass pipe 100, and the temperature of the reboiler heat medium 62 is adjusted to the reboiler allowable temperature.

[0164] Specifically, the flow rate control valve 91a adjusts the temperature of the reboiler heat medium 62 to the reboiler allowable temperature based on the temperature of the heat medium detected by the temperature detection unit 94. In addition, the flow rate control valve 92a and the flow rate control valve 100a adjust the flow rate of the heat medium (mixed heat medium) supplied to the reboiler 40 to the set flow rate of the reboiler 40.

[0165] The heat medium (mixed heat medium) supplied to the heat storage section 81 via the heat storage section heat medium supply pipe 92 heats the heat storage material. This causes the heat storage material to store heat. The heat medium (mixed heat medium) discharged from the heat storage section 81 is mixed with the heat medium (mixed heat medium) introduced via the bypass pipe 100, and is supplied to the reboiler 40 via the reboiler heat medium supply pipe 93 as the reboiler heat medium 62.

[0166] In this manner, in the process of storing heat in the heat storage unit 81, if the temperature of the heat medium (mixed heat medium) detected by the temperature detection unit 95 is equal to the temperature of the heat medium (mixed heat medium) introduced into the heat storage unit 81 via the heat storage unit heat medium supply pipe 92, for example, the flow rate adjustment valve 92a is closed. In this case, it means that the amount of heat stored in the heat storage unit 81 has exceeded the heat storage upper limit heat amount. The temperature of the heat medium (mixed heat medium) introduced into the heat storage unit 81 is detected by a temperature detection unit (not shown) provided in the heat storage unit heat medium supply pipe 92.

[0167] When the flow rate control valve 92a is closed, the flow rate control valve 91a adjusts the temperature of the heat medium (mixed heat medium) introduced into the reboiler heat medium supply pipe 93 via the bypass pipe 100 to the reboiler allowable temperature based on the temperature of the heat medium detected by the temperature detection unit 94. In addition, the flow rate control valve 100a adjusts the flow rate of the heat medium (mixed heat medium) introduced into the reboiler heat medium supply pipe 93 to the set flow rate of the reboiler 40.

[0168] Next, the operation of the heat storage device 80 when dissipating heat will be described.

[0169] Here, the heat dissipation action will be explained separately for the case where the heat medium (mixed heat medium) in the heat storage section 81 is heated to the reboiler allowable temperature, and the case where the heat medium (mixed heat medium) in the heat storage section 81 is heated to a temperature exceeding the reboiler allowable temperature.

[0170] First, a case where the heat medium (mixed heat medium) is heated to the reboiler allowable temperature in the heat storage section 81 will be described.

[0171] When the heat is released, the flow rate regulating valve 100a is closed. That is, the mixed heat medium from the heat storage section heat medium supply pipe 92 does not flow through the bypass pipe 100.

[0172] When releasing heat, the flow rate regulating valve 91a is adjusted so that the flow rate of the low-temperature heat medium introduced from the low-temperature heat medium inlet pipe 91 to the heat storage section heat medium supply pipe 92 is greater than the flow rate of the high-temperature heat medium introduced from the high-temperature heat medium inlet pipe 90 to the heat storage section heat medium supply pipe 92. Specifically, the flow rate regulating valve 91a is adjusted so that the temperature of the heat medium supplied from the heat storage section heat medium supply pipe 92 to the heat storage section 81 is lower than the reboiler allowable temperature.

[0173] When dissipating heat, all the heat medium introduced into the heat storage section heat medium supply pipe 92 may be the low-temperature heat medium from the low-temperature heat medium introduction pipe 91. In this case, a flow rate control valve (not shown) provided in the high-temperature heat medium introduction pipe 90 is closed.

[0174] Here, an example of a situation in which the heat dissipation process is performed is when a plant or the like is operating at a low load and the temperature of the heat medium introduced therein drops.

[0175] The heat medium (mixed heat medium) supplied to the heat storage section 81 via the heat storage section heat medium supply pipe 92 removes heat from the heat storage material. This heats the heat medium (mixed heat medium) to a reboiler allowable temperature. The heat medium (mixed heat medium) discharged from the heat storage section 81 is supplied to the reboiler 40 via the reboiler heat medium supply pipe 93 as the reboiler heat medium 62.

[0176] In this manner, in the process of releasing the heat quantity from the heat storage section 81, when the temperature of the reboiler heat medium 62 detected by the temperature detection section 95 falls below the lower limit threshold, the flow rate control valve 92a is closed and the flow rate control valve 100a is opened. Then, the flow rate control valve 91a is also adjusted.

[0177] When the temperature of the heat storage section heat medium 74 discharged from the heat storage section 81 falls below the lower limit threshold, it means that the amount of heat stored in the heat storage section 81 falls below the lower limit heat storage amount. The lower limit threshold in the heat dissipation process is as described above.

[0178] In this case, the flow rate regulating valve 91a is adjusted so that the temperature of the mixed heat medium in the heat storage section heat medium supply pipe 92 is adjusted to the reboiler allowable temperature. Then, the mixed heat medium adjusted to the reboiler allowable temperature is introduced into the reboiler heat medium supply pipe 93 via the bypass pipe 100. Then, the mixed heat medium is supplied to the reboiler 40 as the reboiler heat medium 62. The flow rate regulating valve 100a is adjusted so that the flow rate of the heat medium (mixed heat medium) introduced into the reboiler heat medium supply pipe 93 becomes the set flow rate of the reboiler 40.

[0179] Next, a case where the heat medium (mixed heat medium) in the heat storage section 81 is heated to a temperature exceeding the reboiler allowable temperature will be described.

[0180] In this case, the flow rate control valve 100a is opened. Then, the heat medium (mixed heat medium) is introduced from the heat storage section heat medium supply pipe 92 to the reboiler heat medium supply pipe 93 through the bypass pipe 100. When a chemical heat storage material is used as the heat storage material, water or steam is supplied from the water supply pipe 82 to the heat storage section 81 when heat is released.

[0181] When releasing heat, the flow control valve 91a is adjusted so that the flow rate of the low-temperature heat medium introduced from the low-temperature heat medium inlet pipe 91 to the heat storage section heat medium supply pipe 92 is greater than the flow rate of the high-temperature heat medium introduced from the high-temperature heat medium inlet pipe 90 to the heat storage section heat medium supply pipe 92. In other words, the temperature of the heat medium supplied from the heat storage section heat medium supply pipe 92 to the heat storage section 81 is set lower than the reboiler allowable temperature, for example.

[0182] When dissipating heat, all the heat medium introduced into the heat storage section heat medium supply pipe 92 may be the low-temperature heat medium from the low-temperature heat medium introduction pipe 91. In this case, a flow rate control valve (not shown) provided in the high-temperature heat medium introduction pipe 90 is closed.

[0183] The heat medium (mixed heat medium) supplied to the heat storage section 81 via the heat storage section heat medium supply pipe 92 removes heat from the heat storage material. This causes the heat medium (mixed heat medium) to be heated. The heat medium (mixed heat medium) discharged from the heat storage section 81 is mixed with the heat medium (mixed heat medium) introduced via the bypass pipe 100, and is supplied to the reboiler 40 via the reboiler heat medium supply pipe 93 as the reboiler heat medium 62.

[0184] In this manner, in the process of releasing the heat quantity from the heat storage section 81, the flow rate control valve 91a adjusts the temperature of the reboiler heat medium 62 to the reboiler allowable temperature based on the temperature of the heat medium detected by the temperature detection section 94. Specifically, the flow rate control valve 91a adjusts the temperature of the heat medium (mixed heat medium) introduced into the reboiler heat medium supply pipe 93 via the bypass pipe 100 so that the temperature of the reboiler heat medium 62 becomes the reboiler allowable temperature.

[0185] In addition, in the process of releasing heat from the heat storage section 81, when the temperature of the reboiler heat medium 62 detected by the temperature detection section 95 falls below the lower limit threshold, the flow rate control valve 92a is closed. The predetermined threshold in the heat release process is as described above.

[0186] Then, the flow rate control valve 91a is adjusted so that the temperature of the mixed heat medium in the heat storage section heat medium supply pipe 92 is adjusted to the reboiler allowable temperature. Also, the flow rate control valve 100a is adjusted so that the flow rate of the heat medium (mixed heat medium) introduced into the reboiler heat medium supply pipe 93 becomes the set flow rate of the reboiler 40.

[0187] According to the carbon dioxide recovery equipment 11 of the second embodiment described above, when an excess of high-temperature heat medium is generated due to high-load operation or the like in a plant or the like that is a supply source of the heat medium, the heat quantity of the excess heat medium can be stored in the heat storage device 80.

[0188] In addition, even if the temperature of the heat medium decreases due to low-load operation of a plant, etc., the heat stored in the heat storage device 80 can be used to supply the reboiler heat medium 62 at an appropriate temperature to the reboiler 40.

[0189] Furthermore, by providing the high-temperature heat medium introduction pipe 90 and the low-temperature heat medium introduction pipe 91, a heat medium at an appropriate temperature can be supplied to the heat storage section 81. Furthermore, even when the exchange of heat in the heat storage section 81 is blocked, by providing the bypass pipe 100, a reboiler heat medium at an optimal temperature and flow rate can be supplied to the reboiler 40.

[0190] In this way, in the carbon dioxide recovery facility 11, surplus heat generated in an external facility such as a plant can be effectively utilized in the reboiler 40. Furthermore, even if a load fluctuation occurs in a plant or the like that is a supply source of the heat medium, the absorption liquid can be appropriately heated in the reboiler 40.

[0191] Here, the configuration of the heat storage section 81 of the heat storage device 80 is not limited to the above-mentioned configuration.

[0192] 6 and 7 are diagrams that show schematic configurations of heat storage devices 80 having other configurations in the carbon dioxide recovery facility 11 according to the second embodiment.

[0193] First, the heat storage device 80 shown in FIG. 6 will be described.

[0194] 6, the heat storage device 80 may include a heat storage section 81A including a chemical heat storage material, and a heat storage section 81B including a latent heat storage material or a sensible heat storage material. The heat storage section 81A is disposed on the heat storage section heat medium supply pipe 92 side, and the heat storage section 81B is disposed on the reboiler heat medium supply pipe 93 side. That is, the heat storage section 81A is provided on the upstream side with respect to the flow of the heat medium (mixed heat medium), and the heat storage section 81B is provided on the downstream side.

[0195] The heat storage unit 81A including the chemical heat storage material includes a water supply pipe 82 and a drain pipe 83. The heat storage unit 81A is connected to a heat storage unit heat medium supply pipe 92. The heat storage unit 81B is connected to a reboiler heat medium supply pipe 93. The heat storage unit 81A and the heat storage unit 81B are connected by a connecting pipe 110.

[0196] First, the operation of storing heat in the heat storage device 80 will be described.

[0197] 6, when storing heat in the heat storage device 80, a heat medium (mixed heat medium) is supplied to the heat storage section 81A via the heat storage section heat medium supply pipe 92. As described above, the heat medium (mixed heat medium) is introduced into the heat exchange pipe 84 in the heat storage section 81A (see FIG. 4).

[0198] The temperature of the heat medium supplied from the heat storage section heat medium supply pipe 92 to the heat storage section 81A is set to be higher than the reboiler allowable temperature, for example. Specifically, the temperature of the heat medium supplied from the heat storage section heat medium supply pipe 92 to the heat storage section 81A is set corresponding to the set heating temperature of the heat storage material of the heat storage section 81.

[0199] In the heat storage unit 81A including the chemical heat storage material, the dehydration reaction occurs in the chemical heat storage material. That is, the heat medium (mixed heat medium) supplied to the heat storage unit 81A heats the chemical heat storage material to cause a dehydration reaction. Water generated by the dehydration reaction is discharged from the drain pipe 83.

[0200] The heat medium (mixed heat medium) that has heated the chemical heat storage material is introduced into the heat storage section 81B through the connecting pipe 110. The heat medium (mixed heat medium) introduced into the heat storage section 81B provides heat to the heat storage material of the heat storage section 81B. As a result, the heat storage material of the heat storage section 81B stores heat. Then, the heat medium (mixed heat medium) that has provided heat to the heat storage material of the heat storage section 81B is introduced into the reboiler heat medium supply pipe 93. The subsequent actions are as described above.

[0201] Next, the operation of the heat storage device 80 when dissipating heat will be described.

[0202] In the heat storage device 80 shown in FIG. 6, when heat is released in the heat storage device 80, a heat medium (mixed heat medium) is supplied to the heat storage section 81A via the heat storage section heat medium supply pipe 92.

[0203] The temperature of the heat medium supplied from the heat storage section heat medium supply pipe 92 to the heat storage section 81A is set to be lower than the reboiler allowable temperature, for example.

[0204] In the heat storage unit 81A including the chemical heat storage material, the hydration reaction occurs in the chemical heat storage material. That is, water or steam is supplied to the heat storage unit 81A from the water supply pipe 82, and heat is released from the chemical heat storage material by the hydration reaction. The heat release heats the heat medium (mixed heat medium) flowing through the heat exchange pipe 84.

[0205] The heated heat medium (mixed heat medium) passes through the connecting pipe 110 and is introduced into the heat storage section 81B. The heat medium (mixed heat medium) introduced into the heat storage section 81B removes heat from the heat storage material of the heat storage section 81B and is further heated. Then, the heated heat medium (mixed heat medium) is introduced into the reboiler heat medium supply pipe 93. The subsequent operations are as described above.

[0206] According to the above-mentioned heat storage device 80, by providing a heat storage section 81A of a chemical heat storage material on the upstream side, for example, when the heat storage section 81B is set to an initial state, steam at an appropriate temperature can be supplied to the heat storage section 81B by utilizing the hydration reaction of the heat storage section 81A without adjusting the temperature of the mixed heat medium.

[0207] Furthermore, by providing a latent heat storage material or a sensible heat storage material on the downstream side, even if a high-temperature heat medium is discharged from heat storage section 81A during the heat storage process, the heat contained in the high-temperature heat medium can be stored in heat storage section 81B.

[0208] Next, the heat storage device 80 shown in FIG. 7 will be described.

[0209] 7, the heat storage device 80 may include a heat storage section 81C including a sensible heat storage material and a heat storage section 81D including a latent heat storage material. The heat storage section 81C is disposed on the heat storage section heat medium supply pipe 92 side, and the heat storage section 81D is disposed on the reboiler heat medium supply pipe 93 side. That is, the heat storage section 81C is provided on the upstream side with respect to the flow of the heat medium (mixed heat medium), and the heat storage section 81D is provided on the downstream side.

[0210] The heat storage unit 81C is connected to a heat storage unit heat medium supply pipe 92. The heat storage unit 81D is connected to a reboiler heat medium supply pipe 93. A connecting pipe 111 connects the heat storage unit 81C and the heat storage unit 81D.

[0211] First, the operation of storing heat in the heat storage device 80 will be described.

[0212] 7, when storing heat in the heat storage device 80, a heat medium (mixed heat medium) is supplied to the heat storage section 81C via the heat storage section heat medium supply pipe 92. The temperature of the heat medium supplied from the heat storage section heat medium supply pipe 92 to the heat storage section 81C is set to be higher than the reboiler allowable temperature, for example. Specifically, the temperature of the heat medium supplied from the heat storage section heat medium supply pipe 92 to the heat storage section 81C is set corresponding to the set heating temperature of the heat storage material of the heat storage section 81C.

[0213] The heat medium (mixed heat medium) supplied to the heat storage unit 81C provides heat to the sensible heat storage material of the heat storage unit 81C, whereby the sensible heat storage material of the heat storage unit 81C stores heat.

[0214] The heat medium (mixed heat medium) that has heated the sensible heat storage material is introduced into heat storage section 81D through connecting pipe 111. The heat medium (mixed heat medium) introduced into heat storage section 81D provides heat to the latent heat storage material in heat storage section 81D. As a result, the latent heat storage material in heat storage section 81D stores heat. Then, the heat medium (mixed heat medium) that has provided heat to the latent heat storage material in heat storage section 81D is introduced into reboiler heat medium supply pipe 93. The subsequent operations are as described above.

[0215] Next, the operation of the heat storage device 80 when dissipating heat will be described.

[0216] 7, when heat is released in the heat storage device 80, a heat medium (mixed heat medium) is supplied to the heat storage section 81C via the heat storage section heat medium supply pipe 92. The temperature of the heat medium supplied from the heat storage section heat medium supply pipe 92 to the heat storage section 81C is set to be lower than the reboiler allowable temperature, for example.

[0217] The heat medium (mixed heat medium) supplied to the heat storage unit 81C absorbs heat from the sensible heat storage material of the heat storage unit 81C and is heated.

[0218] The heated heat medium (mixed heat medium) passes through the connecting pipe 111 and is introduced into the heat storage unit 81D. The heat medium (mixed heat medium) introduced into the heat storage unit 81D removes heat from the sensible heat storage material of the heat storage unit 81D and is further heated. Then, the heated heat medium (mixed heat medium) is introduced into the reboiler heat medium supply pipe 93. The subsequent operations are as described above.

[0219] According to the above-mentioned heat storage device 80, by providing a heat storage section 81D of latent heat storage material on the downstream side, for example, even if the outlet temperature of the heat storage section 81C is higher than the melting point of the latent heat storage material of the heat storage section 81D, a heat medium (mixed heat medium) of a reboiler allowable temperature can be introduced into the reboiler heat medium supply pipe 93.

[0220] Furthermore, by providing the heat storage unit 81D of latent heat storage material on the downstream side, the sensible heat storage material of the heat storage unit 81C can be heated with a high-temperature heat medium (mixed heat medium) that exceeds the reboiler allowable temperature. This increases the amount of heat stored in the heat storage unit 81C compared to when the heat storage units 81C and 81D are made of only sensible heat storage material or only latent heat storage material.

[0221] (Third embodiment) FIG. 8 is a system diagram of a reboiler heat medium supply mechanism 50C in the carbon dioxide recovery facility 12 according to the third embodiment.

[0222] The carbon dioxide recovery equipment 12 of the third embodiment has the same configuration as the carbon dioxide recovery equipment 10 of the first embodiment, except for the reboiler heat medium supply mechanism 50C. Therefore, the configuration of the reboiler heat medium supply mechanism 50C will be mainly described here.

[0223] The reboiler heat medium supply mechanism 50C includes a configuration for supplying a heat medium to the reboiler 40. As shown in FIG. 8, the reboiler heat medium supply mechanism 50C includes a heat accumulator 80 and a heat supply mechanism 70C.

[0224] The heat storage unit 81 of the heat storage device 80 is composed of a latent heat storage material or a sensible heat storage material. The heat storage device 80 may be configured to include a heat storage unit 81C including a sensible heat storage material and a heat storage unit 81D including a latent heat storage material, as shown in Fig. 7. The configuration of each heat storage material is as described above.

[0225] The heat supply mechanism 70C has a configuration for heating the heat storage section 81 of the heat storage device 80 and supplying the amount of heat stored in the heat storage section 81 to the reboiler 40. As shown in FIG. 8 , the heat supply mechanism 70C has a heat storage section heat medium supply pipe 120, a heat storage section heat medium discharge pipe 121, a heat exchange pipe 124, and a circulation pipe 130.

[0226] The heat storage section heat medium supply pipe 120 supplies the heat storage section heat medium 123 to the heat storage section 81 of the heat storage device 80. As the heat storage section heat medium 123, for example, steam (water vapor) generated in a thermal power plant, a steel plant, a waste incineration plant, or the like in which the carbon dioxide recovery facility 12 is installed is used.

[0227] The heat storage section heat medium discharge pipe 121 discharges the heat storage section heat medium 123 supplied from the heat storage section heat medium supply pipe 120 from the heat storage section 81. For example, when the carbon dioxide recovery facility 12 is installed in a thermal power plant equipped with a steam turbine, the heat storage section heat medium 123 condensed into water in the heat storage section 81 is introduced through the heat storage section heat medium discharge pipe 121 into a water supply pipe between a condenser and a boiler.

[0228] The heat storage section heat medium discharge pipe 121 is provided with a temperature detection unit 125 that detects the temperature of the heat storage section heat medium 123 discharged from the heat storage section 81 (heat exchange piping 124). The temperature detection unit 125 is provided in the heat storage section heat medium discharge pipe 121 on the heat storage device 80 side.

[0229] For example, a heat exchange pipe 124 is arranged in a serpentine manner inside the heat storage unit 81. One end of the heat exchange pipe 124 is connected to the heat storage unit heat medium supply pipe 120. The other end of the heat exchange pipe 124 is connected to the heat storage unit heat medium discharge pipe 121.

[0230] The circulation pipe 130 circulates the circulating heat medium 131 to the heat storage section 81 and the reboiler 40. The circulation pipe 130 includes a supply circulation pipe 130A that supplies the circulating heat medium 131 from the heat storage device 80 to the reboiler 40, and a return circulation pipe 130B that returns the circulating heat medium 131 from the reboiler 40 to the heat storage device 80.

[0231] The circulation pipe 130 also includes, for example, a circulation pump 132 that circulates the circulating heat medium 131. Here, an example is shown in which the circulation pump 132 is provided in the return circulation pipe 130B. Note that the circulation pump 132 may also be provided in the supply circulation pipe 130A.

[0232] The supply / circulation pipe 130A is provided with a temperature detector 133 that detects the temperature of the circulating heat medium 131 discharged from the heat storage section 81. The temperature detector 133 is provided on the supply / circulation pipe 130A on the heat storage device 80 side.

[0233] Here, for example, air, steam, pressurized water, oil, molten salt, inorganic hydrate, etc. are used as the circulating heat medium 131. In this way, the circulating heat medium 131 may be composed of, for example, a material different from that of the heat storage section heat medium 123. Note that the circulating heat medium 131 may be composed of the same material as that of the heat storage section heat medium 123.

[0234] Next, the operation of the reboiler heat medium supply mechanism 50C will be described.

[0235] Here, at the start of operation, the heat storage section 81 of the heat storage device 80 is preferably in the initial state described above.

[0236] Furthermore, in the reboiler heat medium supply mechanism 50C, the heat storage action in the heat storage device 80 and the supply action of the circulating heat medium 131 to the reboiler 40 can be carried out independently.

[0237] First, the operation of storing heat in the heat storage device 80 will be described.

[0238] When storing heat, the heat storage section heat medium 123 is supplied from the heat storage section heat medium supply pipe 120 to the heat storage section 81 (heat exchange pipe 124). The temperature of the heat storage section heat medium 123 supplied from the heat storage section heat medium supply pipe 120 to the heat storage section 81 is set to, for example, a reboiler allowable temperature. The temperature of the heat storage section heat medium 123 is set corresponding to the set heating temperature of the heat storage material of the heat storage section 81.

[0239] The heat storage section heat medium 123 supplied to the heat storage section 81 (heat exchange piping 124) via the heat storage section heat medium supply pipe 120 heats the heat storage material. This causes the heat storage material to store heat. The heat storage section heat medium 123 whose heat has been absorbed by the heat storage section 81 is discharged from the heat exchange piping 124 to the heat storage section heat medium discharge pipe 121.

[0240] Here, when the temperature detection unit 125 detects that the temperature of the heat storage section heat medium 123 discharged from the heat storage section 81 is equal to the temperature of the heat storage section heat medium 123 supplied to the heat storage section 81, it means that the amount of heat stored in the heat storage section 81 has exceeded the heat storage upper limit heat amount. In this case, for example, the supply of the heat storage section heat medium 123 to the heat exchange pipe 124 is stopped.

[0241] Next, the operation of the heat storage device 80 when dissipating heat will be described.

[0242] The circulating heat medium 131 introduced from the return circulation pipe 130B to the heat storage section 81 removes heat from the heat storage material. This heats the circulating heat medium 131 to a reboiler allowable temperature. The heated circulating heat medium 131 is discharged from the heat storage section 81 and supplied to the reboiler 40 via the supply circulation pipe 130A.

[0243] The circulating heat medium 131 that has heated the lean liquid 32 in the reboiler 40 is circulated again to the heat storage section 81 via the return circulation pipe 130B.

[0244] Here, when the temperature detection unit 133 detects that the temperature of the circulating heat medium 131 discharged from the heat storage unit 81 is below the lower limit threshold, it means that the amount of heat stored in the heat storage unit 81 is below the lower limit heat storage amount. The lower limit threshold in the heat dissipation process is as described above. In this case, the operation of the circulation pump 132 is stopped, and the supply of the circulating heat medium 131 to the heat storage unit 81 is stopped.

[0245] When performing heat dissipation while storing heat, when the temperature of the circulating heat medium 131 discharged from the heat storage section 81 falls below the lower threshold, as described above, the operation of the circulating pump 132 is stopped and the supply of the circulating heat medium 131 to the heat storage section 81 is stopped.

[0246] In addition, when performing heat storage function while performing heat dissipation function, in order to continue both functions, it is preferable that the amount of heat stored in heat storage section 81 in the heat storage system is greater than the amount of heat removed from heat storage section 81 in the heat dissipation system.

[0247] Here, the heat stored in the heat storage material may be used by utilizing a heat storage system. Specifically, for example, a heat medium with a lower temperature than the heat storage heat medium 123 may be supplied to the heat storage unit 81 (heat exchange piping 124) via the heat storage unit heat medium supply pipe 120. In this case, the low-temperature heat medium supplied to the heat storage unit 81 removes heat from the heat storage material and is heated. This allows the heat medium supplied from the external facility to be heated and returned to the external facility, for example.

[0248] In this case, when the temperature detection unit 125 detects that the temperature of the heat medium discharged from the heat storage unit 81 to the heat storage unit heat medium discharge pipe 121 has fallen below a predetermined threshold, it means that the amount of heat stored in the heat storage unit 81 has fallen below the lower limit heat storage amount. In this case, the supply of low-temperature heat medium to the heat storage unit 81 is stopped.

[0249] Here, the predetermined threshold is set to, for example, the same threshold as the lower limit threshold described above, i.e., 130° C., which is the lower limit of the allowable reboiler temperature.

[0250] The low-temperature heat medium may be supplied to the heat storage unit 81 from the heat storage unit heat medium discharge pipe 121. In this case, the heat storage unit heat medium supply pipe 120 is provided with a temperature detection unit that detects the temperature of the heat medium discharged from the heat storage unit 81 (heat exchange pipe 124).

[0251] According to the carbon dioxide recovery equipment 12 of the third embodiment described above, the heat storage action in the heat storage device 80 and the supply action of the circulating heat medium 131 to the reboiler 40 can be executed independently. This makes it possible to operate only one of the heat storage action in the heat storage device 80 and the supply action of the circulating heat medium 131 to the reboiler 40, or to operate both simultaneously.

[0252] Furthermore, in the reboiler heat medium supply mechanism 50C of the carbon dioxide recovery facility 12, the heat storage section heat medium 123 supplied from the external facility can be returned to the external facility without directly contacting the heat storage material of the heat storage device 80. This is therefore effective in cases where purity is required for the heat storage section heat medium 123 returned to the external facility.

[0253] In the reboiler heat medium supply mechanism 50C, the circulating heat medium 131 and the heat storage section heat medium 123 can be made of different materials. In other words, the reboiler heat medium supply mechanism 50C can be used even when the material of the circulating heat medium 131 and the material of the heat storage section heat medium 123 are different.

[0254] In addition, in the carbon dioxide recovery facility 12, when excess high-temperature heat medium is generated due to high-load operation or the like in a plant or the like that is a supply source of the heat medium, the heat quantity of the excess heat medium can be stored in the heat storage device 80.

[0255] In this way, in the carbon dioxide recovery facility 12, surplus heat generated in an external facility such as a plant can be effectively utilized in the reboiler 40. In addition, even if a load fluctuation occurs in a plant or the like that is a supply source of the heat medium, the absorption liquid can be appropriately heated in the reboiler 40.

[0256] (Fourth embodiment) FIG. 9 is a system diagram of a reboiler heat medium supply mechanism 50D in the carbon dioxide recovery facility 13 according to the fourth embodiment.

[0257] The carbon dioxide recovery equipment 13 of the fourth embodiment has the same configuration as the carbon dioxide recovery equipment 10 of the first embodiment, except for the reboiler heat medium supply mechanism 50D. Therefore, the configuration of the reboiler heat medium supply mechanism 50D will be mainly described here.

[0258] The reboiler heat medium supply mechanism 50D includes a configuration for supplying a heat medium to the reboiler 40. As shown in FIG. 9, the reboiler heat medium supply mechanism 50D includes a heat accumulator 80 and a heat supply mechanism 70D.

[0259] The heat storage section 81 of the heat storage device 80 is made of a latent heat storage material. The configuration of the latent heat storage material is as described above.

[0260] The heat supply mechanism 70D has a configuration for heating the heat storage section 81 of the heat storage device 80 and supplying the amount of heat stored in the heat storage section 81 to the reboiler 40. The heat supply mechanism 70D has a heat storage section heat medium supply pipe 140, a heat storage section heat medium discharge pipe 141, and a heat exchange pipe 142, as shown in FIG.

[0261] The heat storage section heat medium supply pipe 140 supplies the heat storage section heat medium 143 to heat exchange pipes 142 provided in the reboiler 40. As the heat storage section heat medium 143, for example, steam (water vapor) generated in a thermal power plant, a steel plant, a waste incineration plant, or the like in which the carbon dioxide recovery facility 10 is installed is used. The heat storage section heat medium supply pipe 140 functions as a heat medium supply pipe.

[0262] The heat storage section heat medium discharge pipe 141 discharges the heat storage section heat medium 143 supplied from the heat storage section heat medium supply pipe 140 from the heat exchange pipe 142. For example, when the carbon dioxide recovery facility 13 is installed in a thermal power plant equipped with a steam turbine, the heat storage section heat medium 143 condensed into water in the heat exchange pipe 142 is introduced into a water supply pipe between a condenser and a boiler via the heat storage section heat medium discharge pipe 141. The heat storage section heat medium discharge pipe 141 functions as a heat medium discharge pipe.

[0263] The heat storage section heat medium discharge pipe 141 is provided with a temperature detection unit 144 that detects the temperature of the heat storage section heat medium 143 discharged from the heat storage section 81 (heat exchange piping 142). The temperature detection unit 144 is provided on the heat storage section heat medium discharge pipe 141 on the reboiler 40 side.

[0264] For example, a heat exchange pipe 142 is arranged in a serpentine manner in the reboiler 40. One end of the heat exchange pipe 142 is connected to the heat storage section heat medium supply pipe 140. The other end of the heat exchange pipe 142 is connected to the heat storage section heat medium discharge pipe 141.

[0265] The heat storage device 80 is provided so as to cover the periphery of the heat exchange pipe 142. Specifically, the heat storage device 80 is configured by filling a plurality of latent heat storage materials into a tubular container provided along the heat exchange pipe 142. The latent heat storage materials are filled into the tubular container so as to be in contact with the periphery of the heat exchange pipe 142. The heat storage section 81 is configured inside the tubular container.

[0266] Here, a circulation pipe 41 that circulates the lean liquid 32 (absorption liquid) from the reboiler 40 to the regenerator 30 is provided with a temperature detection unit 42 that detects the temperature of the lean liquid 32 discharged from the reboiler 40. The temperature detection unit 42 is provided on the circulation pipe 41 on the reboiler 40 side.

[0267] Next, the operation of the reboiler heat medium supply mechanism 50D will be described.

[0268] Here, at the start of operation, the heat storage section 81 of the heat storage device 80 is preferably in the initial state described above.

[0269] First, the operation of storing heat in the heat storage device 80 will be described.

[0270] When storing heat, the heat storage section heat medium 143 is supplied from the heat storage section heat medium supply pipe 140 to the heat storage section 81 (heat exchange pipe 142). The temperature of the heat storage section heat medium 143 supplied from the heat storage section heat medium supply pipe 140 to the heat storage section 81 is set to, for example, a reboiler allowable temperature. The temperature of the heat storage section heat medium 143 is set corresponding to the set heating temperature of the heat storage material of the heat storage section 81.

[0271] The heat storage section heat medium 143 supplied to the heat storage section 81 (heat exchange piping 142) via the heat storage section heat medium supply pipe 140 heats the heat storage material provided around the heat exchange piping 142. This causes the heat storage material to store heat. The heat storage section heat medium 143 whose heat has been absorbed by the heat storage section 81 is discharged from the heat exchange piping 142 to the heat storage section heat medium discharge pipe 141. In this case, the supply of the heat storage section heat medium 143 to the heat exchange piping 142 is stopped.

[0272] Here, when the temperature detection unit 125 detects that the temperature of the heat storage section heat medium 143 discharged from the heat storage section 81 is equal to the temperature of the heat storage section heat medium 143 supplied to the heat storage section 81, this means that the amount of heat stored in the heat storage section 81 has exceeded the upper limit heat storage amount.

[0273] Next, the operation of the heat storage device 80 when dissipating heat will be described.

[0274] The lean liquid 32 (absorption liquid) introduced from the circulation pipe 41 into the reboiler 40 removes heat from the heat storage material by flowing around the heat storage device 80. As a result, the lean liquid 32 is heated to a reboiler allowable temperature. The heated lean liquid 32 is discharged from the reboiler 40 and supplied to the regenerator 30 via the circulation pipe 41.

[0275] Here, when the temperature of the lean liquid 32 discharged from the reboiler 40 falls below a predetermined threshold, it means that the amount of heat stored in the heat storage section 81 falls below the lower limit heat storage amount. In this case, the predetermined threshold is the set temperature (about 110 to 130°C) of the lean liquid 32 circulated from the reboiler 40 to the regenerator 30. In this case, the circulation of the lean liquid 32 from the reboiler 40 to the regenerator 30 is stopped.

[0276] During the heat dissipation action, the above-mentioned heat storage action may also be performed.

[0277] According to the carbon dioxide recovery system 13 of the fourth embodiment described above, by providing the heat accumulator 80 in the reboiler 40, the configuration of the reboiler heat medium supply mechanism 50D can be made compact.

[0278] 9, the reboiler heat medium supply mechanism 50D can return the heat storage section heat medium 143 supplied from the external facility to the external facility without directly contacting the heat storage material of the heat storage device 80. This is therefore effective when the heat storage section heat medium 143 returned to the external facility must have a high purity.

[0279] In addition, in the carbon dioxide recovery equipment 13, when excess high-temperature heat medium is generated in a plant or the like that is a supply source of the heat medium due to high-load operation, the heat capacity of the excess heat medium can be stored in the heat storage device 80.

[0280] In this way, in the carbon dioxide recovery facility 13, surplus heat generated in an external facility such as a plant can be effectively utilized in the reboiler 40. In addition, even if a load fluctuation occurs in a plant or the like that is a supply source of the heat medium, the absorption liquid can be appropriately heated in the reboiler 40.

[0281] Here, the configuration of the reboiler heat medium supply mechanism 50D is not limited to the above-mentioned configuration. Fig. 10 is a system diagram of a reboiler heat medium supply mechanism 50D having another configuration in the carbon dioxide recovery facility 13 of the fourth embodiment.

[0282] 10, the heat exchange pipe 142 and the heat storage device 80 may be provided in a circulation system of the lean liquid 32 (absorption liquid). Specifically, for example, the heat exchange pipe 142 is arranged in a serpentine manner in the reboiler 40. One end of the heat exchange pipe 142 is connected to the circulation pipe 41 that discharges the lean liquid 32 from the reboiler 40. The other end of the heat exchange pipe 142 is connected to the circulation pipe 41 that returns the lean liquid 32 to the reboiler 40.

[0283] The heat storage device 80 is provided so as to cover the periphery of the heat exchange pipe 142. The configuration of the heat storage device 80 is the same as the configuration of the heat storage device 80 described with reference to FIG.

[0284] In the reboiler heat medium supply mechanism 50D shown in Fig. 10, when storing heat, the heat storage section heat medium 143 is supplied from the heat storage section heat medium supply pipe 140 into the reboiler 40. The heat storage section heat medium 143 supplied into the reboiler 40 flows around the heat storage device 80, thereby heating the heat storage material provided around the heat exchange pipe 142. As a result, the heat storage material stores heat. The heat storage section heat medium 143 from which heat has been absorbed by the heat storage section 81 is discharged from the reboiler 40 to the heat storage section heat medium discharge pipe 141.

[0285] On the other hand, when dissipating heat, the lean liquid 32 (absorption liquid) introduced from the circulation pipe 41 to the reboiler 40 flows through the heat exchange pipe 142 and removes heat from the heat storage material. As a result, the lean liquid 32 is heated to the above-mentioned set temperature. The heated lean liquid 32 generates steam (water vapor). Then, the lean liquid 32 containing the steam is introduced from the heat exchange pipe 142 to the circulation pipe 41 and supplied to the regenerator 30.

[0286] In a reboiler heat medium supply mechanism 50D having another configuration shown in FIG. 10, by providing a heat accumulator 80 inside the reboiler 40, the configuration of the reboiler heat medium supply mechanism 50D can be made compact.

[0287] In addition, in the reboiler heat medium supply mechanism 50D having another configuration, when an excess of high-temperature heat medium is generated due to high-load operation or the like in a plant or the like that is a supply source of the heat medium, the heat quantity of the excess heat medium can be stored in the heat storage device 80.

[0288] In this way, in the reboiler heat medium supply mechanism 50D having another configuration, the surplus heat generated in an external facility such as a plant can be effectively utilized in the reboiler 40. In addition, even if a load fluctuation occurs in a plant or the like that is a supply source of the heat medium, the absorption liquid can be appropriately heated in the reboiler 40.

[0289] In each of the above-described embodiments, an electric heater may be provided in addition to the heat medium as the heating means for the heat storage section.

[0290] According to the embodiment described above, the amount of heat provided from an external facility such as a plant can be effectively utilized in the reboiler, and the absorption liquid can be appropriately heated in the reboiler.

[0291] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented 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 modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0292] 10, 11, 12, 13... Carbon dioxide recovery equipment, 20... Absorption tower, 21... Absorption section, 22... Exhaust port, 23... Rich liquid, 24... Exhaust gas inlet pipe, 24a... Exhaust gas blower, 25... Rich liquid inlet pipe, 26... Heat exchanger, 27... Rich liquid pump, 30... Regeneration tower, 31... Regeneration section, 32... Lean liquid, 33... Carbon dioxide exhaust port, 34... Carbon dioxide exhaust pipe, 35... Gas-liquid separator, 35 a...recovery port, 35b...drain pipe, 36, 39...cooler, 37...lean liquid introduction pipe, 38...lean liquid pump, 40...reboiler, 41, 130...circulation pipe, 42, 63, 75, 76, 94, 95, 125, 133, 144...temperature detection unit, 50A, 50B, 50C, 50D...reboiler heat medium supply mechanism, 60, 93...reboiler heat medium supply pipe, 61...reboiler heat medium discharge pipe , 62... Reboiler heat medium, 70A, 70B, 70C, 70D... Heating supply mechanism, 71... Communication piping, 72... Heat medium discharge pipe, 72a, 73a, 85a, 91a, 92a, 100a... Flow rate Regulating valve, 73, 92, 120, 140... Heat storage unit heat medium supply pipe, 74, 123, 143... Heat storage unit heat medium, 80... Heat storage device, 81, 81A, 81B, 81C, 81D... Heat storage unit, 82... Supply Water pipe, 83...drain pipe, 84, 124, 142...heat exchange piping, 85, 100...bypass pipe, 86...equipment container, 87...chemical heat storage material, 88...container, 90...high temperature heat medium inlet pipe, 91...low temperature heat medium inlet pipe, 110, 111...connecting pipes, 121, 141...heat storage section heat medium discharge pipe, 130A...supply circulation piping, 130B...return circulation piping, 131...circulating heat medium, 132...circulation pump.

Claims

1. an absorption tower into which a carbon dioxide-containing exhaust gas to be treated is introduced and into which the carbon dioxide is absorbed in an absorption liquid containing water; a regeneration tower that releases carbon dioxide from the absorption liquid supplied from the absorption tower; A reboiler that heats the absorption liquid in the regeneration tower to generate steam; a heat storage unit that stores a heat amount required to generate steam from the absorption liquid in the reboiler and to supply a reboiler heat medium having a reboiler allowable temperature to the reboiler; a heat supply mechanism having a configuration for heating the heat storage unit and supplying the amount of heat stored in the heat storage unit to the reboiler; Equipped with The heat supply mechanism includes: a heat storage section heat medium supply pipe that supplies a first heat medium, which is an excess heat medium generated in an external facility and satisfies the reboiler allowable temperature, to the heat storage section; a heat storage section heat medium discharge pipe that discharges the first heat medium from the heat storage section; a circulation pipe for circulating a circulation heat medium that functions as the reboiler heat medium to the heat storage unit and the reboiler; Equipped with When storing heat in the heat storage section, The first heat medium introduced into the heat storage unit through the heat storage unit heat medium supply pipe provides the heat quantity to the heat storage unit and is discharged from the heat storage unit through the heat storage unit heat medium discharge pipe, When heat is released from the heat storage section, the circulating heat medium introduced into the heat storage unit through the circulation piping removes the heat from the heat storage unit to satisfy the reboiler allowable temperature, and is supplied to the reboiler through the circulation piping.

2. 2. The carbon dioxide recovery facility according to claim 1, wherein the heat storage unit comprises a latent heat storage material.

3. 2. The carbon dioxide recovery facility according to claim 1, wherein the heat storage section comprises a sensible heat storage material.

4. The heat storage unit is A first heat storage unit including a sensible heat storage material; A second heat storage unit including a latent heat storage material; a connecting pipe connecting the first heat storage unit and the second heat storage unit; The carbon dioxide recovery facility according to claim 1, further comprising:

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