Carbon dioxide recovery device
Patent Information
- Application Number
- PCT/JP2025/011841
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-03-25
- Publication Date
- 2026-10-01
Smart Images
Figure JP2025011841_01102026_PF_FP_ABST
Abstract
Description
Carbon dioxide capture device
[0001] This invention relates to a carbon dioxide recovery device.
[0002] Efforts to mitigate or reduce the impact of climate change have been ongoing, and research and development on carbon dioxide capture devices are being conducted to achieve this. Furthermore, technologies that utilize heat sources such as heat pumps in systems that heat or cool target equipment using a heat transfer medium are known. Patent document 1, for example, describes this type of technology. Patent document 1 describes setting the feedwater temperature of the water supplied to the steam system of a boiler.
[0003] Japanese Patent Publication No. 2010-032173
[0004] In carbon dioxide recovery devices, which use a module with an adsorbent to draw in a gas such as air containing carbon dioxide, adsorb the carbon dioxide onto the adsorbent, and then heat the adsorbent to desorb the adsorbed carbon dioxide and recover it, heat sources such as heat pumps are also used.
[0005] In carbon dioxide capture systems, the adsorption module requires a high-temperature heating fluid, while a low-temperature cooling fluid is also needed for waste heat from each component and for condensing the recovered water vapor. However, a large temperature difference between the heating and cooling fluids increases the energy required for heat exchange in the heat source, so there is a demand to minimize this temperature difference. Furthermore, waste heat from auxiliary equipment such as vacuum pumps and desorbed water condensers is sometimes recovered and used as a heat source for heating the heat fluid. To protect these auxiliary equipment, the temperature of the cooling fluid must be kept low to ensure proper cooling, thus requiring a reduction in the temperature of the cooling fluid. Moreover, fluctuations in ambient temperature due to seasonal factors can cause fluctuations in the amount of waste heat, altering the cooling state, which is undesirable. There is a demand to efficiently dissipate heat to the outside while satisfying these conflicting temperature requirements.
[0006] The present invention aims to provide a carbon dioxide capture device that can simultaneously reduce the power consumption of the heat source and provide protective cooling for auxiliary components. Ultimately, this will contribute to mitigating or reducing the impact of climate change.
[0007] (1) A carbon dioxide recovery device according to one aspect of the present invention (for example, carbon dioxide recovery device 1 described later) includes a module (for example, module 2 described later) that has an adsorbent (for example, adsorbent 11 described later) inside and performs an adsorption step of drawing a gas containing carbon dioxide onto the adsorbent to adsorb the carbon dioxide, and a desorption step of heating the area around the adsorbent to desorb the carbon dioxide from the adsorbent, and a heat pump type heat source (for example, high-temperature water described later) that heats a high-temperature heat transfer medium (for example, high-temperature water described later) and cools a low-temperature heat transfer medium (for example, low-temperature water described later). For example, the module includes a heat exchanger (for example, a heat exchanger 3, described later) having a heat source 21 (described later), a high-temperature heat transfer medium tank (for example, a high-temperature water tank 23, described later) for storing the high-temperature heat transfer medium heated by the heat source, and a low-temperature heat transfer medium tank (for example, a low-temperature water tank 22, described later) for storing the low-temperature heat transfer medium cooled by the heat source, and performing a heating step of supplying the high-temperature heat transfer medium to heat the module and a cooling step of supplying the low-temperature heat transfer medium to cool the module, an auxiliary device (for example, a vacuum pump 61, described later) capable of supplying the low-temperature heat transfer medium for cooling, an auxiliary device connection switching valve (for example, an auxiliary device connection switching valve 63, described later) capable of switching the low-temperature heat transfer medium returning from the module to the low-temperature heat transfer medium tank to the auxiliary device, and a control unit (for example, a control unit 4, described later), wherein when the control unit performs the cooling step of the module, it controls the temperature of the low-temperature heat transfer medium in the low-temperature heat transfer medium tank (T ＬＴ ) From the aforementioned auxiliary equipment, the exhaust heat environment temperature (T ｏｕｔIf the difference obtained by subtracting the temperature of the low-temperature heat transfer medium in the low-temperature heat transfer medium tank is smaller than the first temperature condition (T1), the auxiliary equipment connection switching valve is switched to perform a first cooling step (step S21) in which the low-temperature heat transfer medium is returned from the module to the low-temperature heat transfer medium tank and the low-temperature heat transfer medium is supplied from the low-temperature heat transfer medium tank to the auxiliary equipment. If the difference obtained by subtracting the exhaust heat environment temperature around the auxiliary equipment from the temperature of the low-temperature heat transfer medium in the low-temperature heat transfer medium tank is larger than the first temperature condition, the auxiliary equipment connection switching valve is switched to perform a second cooling step (step S22) in which the low-temperature heat transfer medium is returned from the module to the low-temperature heat transfer medium tank via the auxiliary equipment, or the first cooling step (step S21) is performed.
[0008] In this configuration, when performing the module cooling process, as long as the difference between the temperature of the low-temperature heat transfer medium in the low-temperature heat transfer medium tank and the ambient heat temperature around the auxiliary equipment is smaller than the first temperature condition, the module is cooled by the low-temperature heat transfer medium supplied from the low-temperature heat transfer medium tank as the first cooling process, and the heat transfer medium returns from the module to the low-temperature heat transfer medium tank. At the same time, the auxiliary equipment is cooled by the low-temperature heat transfer medium supplied from the low-temperature heat transfer medium tank via a separate circuit from the module, and the heat transfer medium returns from the auxiliary equipment to the low-temperature heat transfer medium tank. In the first cooling process, even if the ambient heat temperature (outside temperature) is high and there is excess heat from the low-temperature heat transfer medium tank, or even if the temperature of the low-temperature heat transfer medium tank is low, it is possible to perform sufficient cooling of the auxiliary equipment and use this heat as a heat source for the heat source to reduce the temperature difference in the heat source. Furthermore, as long as the above temperature difference is larger than the first temperature condition, the low-temperature heat transfer medium returns from the module to the low-temperature heat transfer medium tank via the auxiliary equipment as the second cooling process. In the second cooling process, the temperature of the low-temperature heat transfer medium flowing from the module to the auxiliary equipment is lowered, thereby sufficiently cooling the auxiliary equipment. This waste heat is then recovered as a heat source for the heat source, reducing the temperature difference in the heat source and allowing the sensible heat of the auxiliary equipment to be released to the outside. This reduces the temperature difference between the high-temperature and low-temperature heat transfer mediums in the heat source, thereby reducing the energy consumption of the heat exchanger. At the same time, sufficient cooling of the auxiliary equipment is ensured, preventing temperature damage to the equipment. In other words, by choosing between lowering the temperature of the module in the adsorption process by flowing a low-temperature heat transfer medium upstream of the auxiliary equipment to be cooled, and separately cooling the module and auxiliary equipment, the minimum necessary cooling can be achieved, satisfying both the temperature requirements of the low-temperature heat source in the heat source and the cooling requirements for the module and auxiliary equipment.
[0009] (2) In the carbon dioxide recovery apparatus described in (1) above, the control unit may, when performing the cooling step of the module, perform the second cooling step (step S22) if the difference between the temperature of the low-temperature heat medium in the low-temperature heat medium tank and the exhaust heat environment temperature around the auxiliary equipment is greater than the first temperature condition, and the temperature of the low-temperature heat medium in the low-temperature heat medium tank is equal to or greater than the second temperature condition (T2); and perform the first cooling step (step S21) if the difference between the temperature of the low-temperature heat medium in the low-temperature heat medium tank and the exhaust heat environment temperature around the auxiliary equipment is greater than the first temperature condition, and the temperature of the low-temperature heat medium in the low-temperature heat medium tank is equal to or less than the second temperature condition.
[0010] In this configuration, during the first cooling process, even if the ambient temperature (outside temperature) is high and there is excess heat from the low-temperature heat transfer medium tank, or even if the temperature of the low-temperature heat transfer medium tank is low, sufficient cooling of the auxiliary components can be performed, and this waste heat can be used as a heat source for the heat source unit, thereby reducing the temperature difference in the heat source unit. In the second cooling process, by lowering the temperature of the low-temperature heat transfer medium flowing to the auxiliary components in the module, the auxiliary components can be sufficiently cooled, and this waste heat can be recovered as a heat source for the heat source unit, reducing the temperature difference in the heat source unit and allowing the sensible heat of the auxiliary components to be discharged to the outside. As a result, the temperature difference between the high-temperature heat transfer medium and the low-temperature heat transfer medium in the heat source unit can be reduced, thereby reducing the energy consumption of the heat exchanger. At the same time, sufficient cooling of the auxiliary components can be performed, preventing temperature damage to the auxiliary components. In other words, by being able to choose between lowering the temperature of the module in the adsorption process by flowing a low-temperature heat transfer medium directly upstream of the auxiliary equipment to be cooled, and cooling the module and auxiliary equipment separately, it is possible to perform the minimum necessary cooling while simultaneously satisfying the temperature requirements of the low-temperature heat source in the heat source unit and the requirements of the module and auxiliary equipment as a cooling source.
[0011] (3) A carbon dioxide recovery device according to one aspect of the present invention includes a module having an adsorbent inside, which performs an adsorption step of drawing a gas containing carbon dioxide onto the adsorbent to adsorb the carbon dioxide, and a desorption step of heating the area around the adsorbent to desorb the carbon dioxide from the adsorbent; a heat exchange device having a heat pump type heat source that heats a high-temperature heat transfer medium and cools a low-temperature heat transfer medium, a high-temperature heat transfer medium tank that stores the high-temperature heat transfer medium heated by the heat source, and a low-temperature heat transfer medium tank that stores the low-temperature heat transfer medium cooled by the heat source, which performs a heating step of supplying the high-temperature heat transfer medium to heat the module and a cooling step of supplying the low-temperature heat transfer medium to cool the module; an auxiliary device that can be cooled by supplying the low-temperature heat transfer medium; and a device that returns the low-temperature heat transfer medium from the module to the low-temperature heat transfer medium tank. The module comprises an auxiliary connection switching valve that can be switched to the auxiliary equipment, and a control unit. When the control unit performs the cooling process of the module, if the difference between the temperature of the low-temperature heat transfer medium in the low-temperature heat transfer medium tank and the temperature of the gas drawn into the module is smaller than a third temperature condition, the control unit switches the auxiliary connection switching valve to return the low-temperature heat transfer medium from the module to the low-temperature heat transfer medium tank and performs a first cooling process (step S21) in which the low-temperature heat transfer medium is supplied from the low-temperature heat transfer medium tank to the auxiliary equipment. If the difference between the temperature of the low-temperature heat transfer medium in the low-temperature heat transfer medium tank and the temperature of the gas drawn into the module is larger than a third temperature condition, the control unit switches the auxiliary connection switching valve to perform a second cooling process (step S22) in which the low-temperature heat transfer medium is returned from the module to the low-temperature heat transfer medium tank via the auxiliary equipment, or the first cooling process (step S21).
[0012] In this configuration, when performing the module cooling process, as long as the difference between the temperature of the low-temperature heat transfer medium in the low-temperature heat transfer medium tank and the temperature of the gas drawn into the module around the auxiliary equipment is smaller than the third temperature condition, the first cooling process involves the low-temperature heat transfer medium being cooled from the low-temperature heat transfer medium tank to the module and then returning from the module to the low-temperature heat transfer medium tank. Simultaneously, the auxiliary equipment is cooled by the low-temperature heat transfer medium supplied from the low-temperature heat transfer medium tank via a separate circuit, and then returns from the auxiliary equipment to the low-temperature heat transfer medium tank. In the first cooling process, even if the temperature of the gas drawn into the module is high and there is excess waste heat from the low-temperature heat transfer medium tank, or if the temperature of the low-temperature heat transfer medium tank is low, it is possible to perform sufficient cooling of the auxiliary equipment and use this waste heat as a heat source for the heat source to reduce the temperature difference in the heat source. Furthermore, as long as the above temperature difference is larger than the third temperature condition, the second cooling process involves the low-temperature heat transfer medium returning from the module to the low-temperature heat transfer medium tank via the auxiliary equipment. In the second cooling process, the temperature of the low-temperature heat transfer medium flowing from the module to the auxiliary equipment is lowered, thereby sufficiently cooling the auxiliary equipment. This waste heat is then recovered as a heat source for the heat source, reducing the temperature difference in the heat source and allowing the sensible heat of the auxiliary equipment to be released to the outside. This reduces the temperature difference between the high-temperature and low-temperature heat transfer mediums in the heat source, thereby reducing the energy consumption of the heat exchanger. At the same time, sufficient cooling of the auxiliary equipment is ensured, preventing temperature damage to the equipment. In other words, by selecting between lowering the temperature of the module in the adsorption process by flowing a low-temperature heat transfer medium upstream of the auxiliary equipment to be cooled, and separately cooling the module and auxiliary equipment, it is possible to perform the minimum necessary cooling while simultaneously satisfying the temperature requirements of the low-temperature heat source in the heat source and the cooling requirements for the module and auxiliary equipment.
[0013] (4) In the carbon dioxide recovery apparatus described in (3) above, the control unit may, when performing the cooling step of the module, perform the second cooling step (step S21) if the difference between the temperature of the low-temperature heat medium in the low-temperature heat medium tank and the temperature of the gas drawn into the module is greater than the third temperature condition, and the temperature of the low-temperature heat medium in the low-temperature heat medium tank is at or above the fourth temperature condition. The control unit may also perform the first cooling step (step S22) if the difference between the temperature of the low-temperature heat medium in the low-temperature heat medium tank and the temperature of the gas drawn into the module is greater than the third temperature condition, and the temperature of the low-temperature heat medium in the low-temperature heat medium tank is at or below the fourth temperature condition.
[0014] In this configuration, during the first cooling process, even if the temperature of the gas drawn into the module is high and there is excess waste heat from the low-temperature heat transfer medium tank, or even if the temperature of the low-temperature heat transfer medium tank is low, sufficient cooling of the auxiliary components can be performed, and this waste heat can be used as a heat source for the heat source unit, thereby reducing the temperature difference in the heat source unit. In the second cooling process, by lowering the temperature of the low-temperature heat transfer medium flowing from the module to the auxiliary components, the auxiliary components can be sufficiently cooled, and this waste heat can be recovered as a heat source for the heat source unit, reducing the temperature difference in the heat source unit and allowing the sensible heat of the auxiliary components to be discharged to the outside. As a result, the temperature difference between the high-temperature heat transfer medium and the low-temperature heat transfer medium in the heat source unit can be reduced, thereby reducing the energy consumption of the heat exchanger. At the same time, sufficient cooling of the auxiliary components can be performed, preventing temperature damage to the auxiliary components. In other words, by being able to choose between lowering the temperature of the module in the adsorption process by flowing a low-temperature heat transfer medium directly upstream of the auxiliary equipment to be cooled, and cooling the module and auxiliary equipment separately, it is possible to perform the minimum necessary cooling while simultaneously satisfying the temperature requirements of the low-temperature heat source in the heat source unit and the requirements of the module and auxiliary equipment as a cooling source.
[0015] (5) The carbon dioxide recovery apparatus described in any of (1) to (4) above includes an auxiliary cooling pump capable of supplying the low-temperature heat transfer medium from the low-temperature heat transfer medium tank to the auxiliary equipment, and the control unit may drive the auxiliary cooling pump when executing the second cooling step.
[0016] In this configuration, during the second cooling process, the auxiliary cooling pump is driven to deliver the cooling medium between the low-temperature heat transfer medium tank and the auxiliary equipment, regardless of the temperature of the low-temperature heat transfer medium. This reduces the energy consumption of the heat exchanger, regardless of the ambient temperature (exhaust heat environment) and the temperature of the gas drawn into the module. At the same time, sufficient cooling of the auxiliary equipment can be achieved, preventing temperature damage to the equipment.
[0017] According to the present invention, it is possible to satisfy both the temperature requirements for the low-temperature heat source in the heat source unit and the requirements for the cooling source for modules and auxiliary equipment in a carbon dioxide recovery device.
[0018] This is a schematic diagram showing a heat exchanger equipped with a low-temperature heat medium supplemental cooling switching mechanism in a carbon dioxide recovery device according to an embodiment of the present invention. This is a flowchart showing the temperature control of the low-temperature heat medium supplemental cooling switching mechanism in a carbon dioxide recovery device according to an embodiment of the present invention.
[0019] <Embodiments> Embodiments of the present invention will be described below with reference to the drawings. In the following description, corresponding components will be denoted by the same reference numerals, and descriptions of overlapping parts may be omitted.
[0020] Figure 1 is a schematic diagram showing the configuration of a heat exchanger equipped with a low-temperature heat transfer medium supplemental cooling switching mechanism in a carbon dioxide recovery device according to this embodiment. In the figure, reference numeral 1 denotes the carbon dioxide recovery device. The carbon dioxide recovery device 1 is applied, for example, to direct air capture technology (DAC) that recovers carbon dioxide from the atmosphere in order to reduce the carbon dioxide concentration in the atmosphere. The carbon dioxide recovered by the carbon dioxide recovery device 1 is stored underground or reused as fuel or material.
[0021] As shown in Figure 1, the carbon dioxide recovery device 1 comprises a module 2, a heat exchanger 3, a control unit 4, a storage unit 5, and a low-temperature water cooling switching mechanism (low-temperature heat transfer medium cooling switching mechanism) 6.
[0022] Module 2 is a carbon dioxide recovery module that includes an adsorbent 11 for adsorbing carbon dioxide and a temperature sensor 12 for measuring the temperature of Module 2.
[0023] The adsorbent 11 is placed inside the module 2 to adsorb carbon dioxide. The adsorbent 11 is a particulate material that adsorbs carbon dioxide at low temperatures (for example, in the range of -30°C to 50°C) and desorbs (releases) carbon dioxide at high temperatures (for example, in the range of 50°C to 110°C) and when the ambient carbon dioxide concentration is low. Examples of such an adsorbent 11 include solid amine carbon dioxide adsorbents composed of amines supported on a porous material such as silica.
[0024] The temperature sensor 12 in module 2 measures the temperature of the adsorbent 11. The measurement information from the temperature sensor 12 is transmitted to the control unit 4. Module 2 includes an inlet-side flow path 13 connected to an inlet through which the heat transfer medium flows in, and an outlet-side flow path 14 connected to an outlet through which the heat transfer medium flows out. The heat transfer medium circulates with the heat exchanger 3, which will be described later, to heat and cool module 2.
[0025] The heat exchanger 3 supplies thermal energy to heat the inside of module 2 to a predetermined temperature when module 2 performs a desorption process (heating process). The heat exchanger 3 also recovers unnecessary thermal energy when each module 2 performs an adsorption process. The heat exchanger 3 of this embodiment includes a heat source circuit 20, a low-temperature water line 30 (low-temperature heat transfer medium line), a high-temperature water line 40 (high-temperature heat transfer medium line), and a three-way valve 50.
[0026] The heat source circuit 20 includes a heat source 21, a low-temperature water tank 22 (low-temperature heat transfer medium tank), a high-temperature water tank 23 (high-temperature heat transfer medium tank), a heat source low-temperature water line 24 (heat source low-temperature heat transfer medium line), and a heat source high-temperature water line 25 (heat source high-temperature heat transfer medium line).
[0027] The heat source 21 is a heat pump type heat source that cools the low-temperature heat transfer medium (heat transfer medium) and heats the high-temperature heat transfer medium (heat transfer medium). The heat source 21 uses the cooling and heating generated by compressing and expanding gas in the heat pump to cool the low-temperature heat transfer medium flowing between it and the low-temperature water tank 22, and to heat the high-temperature heat transfer medium flowing between it and the high-temperature water tank 23. The heat transfer medium is, for example, a liquid such as water.
[0028] The low-temperature water tank 22 stores the low-temperature heat transfer medium cooled by the heat source 21. The high-temperature water tank 23 stores the high-temperature heat transfer medium heated by the heat source 21. The low-temperature water tank 22 is equipped with a temperature sensor 27. The temperature sensor 27 measures the temperature of the low-temperature heat transfer medium stored in the low-temperature water tank 22. The measurement information from the temperature sensor 27 is transmitted to the control unit 4.
[0029] The heat source low-temperature water line 24 is piping for circulating low-temperature water as a low-temperature heat transfer medium between the low-temperature water tank 22 and the heat source unit 21. Although not shown in the figures, the heat source low-temperature water line 24 is equipped with a circulating water pump for pressurizing the low-temperature water. This circulating water pump can circulate high-temperature water between the high-temperature water tank 23 and the heat source unit 21. This circulating water pump may be, for example, a centrifugal pump.
[0030] The heat source high-temperature water line 25 is piping for circulating high-temperature water as a high-temperature heat transfer medium between the high-temperature water tank 23 and the heat source unit 21. Although not shown in the figures, the heat source high-temperature water line 25 is equipped with a circulating water pump for pressurizing the high-temperature water. This circulating water pump allows the high-temperature water to be circulated between the high-temperature water tank 23 and the heat source unit 21. This circulating water pump may be, for example, a centrifugal pump.
[0031] The cold water line 30 is a pipe through which cold water flows. The cold water line 30 branches and connects to the upstream and downstream sides of module 2, connecting the cold water tank 22 and module 2. Of the cold water line 30, the line connected to the inlet channel 13 located upstream of module 2 is designated as the cold water supply line 31, and the line connected to the outlet channel 14 located downstream of module 2 is designated as the cold water return line 32.
[0032] Although not shown in the diagram, a circulating water pump is located in the low-temperature water supply line 31. This circulating water pump flows low-temperature water from the low-temperature water tank 22 towards module 2. For example, a cascade pump is used for this circulating water pump.
[0033] The high-temperature water line 40 is a pipe through which high-temperature water flows. The high-temperature water line 40 branches and connects to the upstream and downstream sides of module 2, connecting the high-temperature water tank 23 and module 2. Of the high-temperature water line 40, the line connected to the inlet channel 13 located upstream of module 2 is designated as the high-temperature water supply line 41, and the line connected to the outlet channel 14 located downstream of module 2 is designated as the high-temperature water return line 42.
[0034] Although not shown in the diagram, a circulating water pump, for example, is located in the high-temperature water supply line 41. This circulating water pump flows high-temperature water from the high-temperature water tank 23 towards module 2. For example, a cascade pump is used for this circulating water pump. By using a cascade pump, which generates a large amount of heat when driven, the high-temperature water (heat transfer medium) passing through the circulating water pump can be further heated.
[0035] The three-way valve 50 is connected to the low-temperature water line 30, the high-temperature water line 40, and the module 2. The three-way valve 50 is positioned on both the upstream and downstream sides of the module 2. The three-way valve 50 is configured to allow selection by switching the flow path between a low-temperature water connection state, where the module 2 is connected only to the low-temperature water line 30; a high-temperature water connection state, where the module 2 is connected only to the high-temperature water line 40; and a disconnection state, where the connection between the low-temperature water line 30 and the high-temperature water line 40 and the module 2 is cut off.
[0036] The flow path switching of the three-way valve 50 is controlled by the control unit 4. A heat transfer medium is introduced into module 2 through the three-way valve 50 located on the upstream side, and the heat transfer medium is returned from module 2 to the heat source 21 side through the three-way valve 50 located on the downstream side. In the following description, the three-way valve 50 located on the upstream side of module 2 will be referred to as three-way valve 50a, and the three-way valve 50 located on the downstream side of module 2 will be referred to as three-way valve 50b.
[0037] A three-way valve 50a is positioned at the upstream end of the inlet-side flow path 13, and a three-way valve 50b is also positioned at the downstream end of the outlet-side flow path 14. When high-temperature water is connected, the three-way valve 50a is connected to the high-temperature water supply line 41, and the three-way valve 50b is connected to the high-temperature water return line 42. When low-temperature water is connected, the three-way valve 50a is connected to the low-temperature water supply line 31, and the three-way valve 50b is connected to the low-temperature water return line 32.
[0038] The three-way valves 50a and 50b are configured to allow for flow rate adjustment. This flow rate adjustment function allows for adjustment of the flow rate of high-temperature water when connected to high-temperature water, and adjustment of the flow rate of low-temperature water when connected to low-temperature water.
[0039] The control unit 4 controls the operation of each part of the carbon dioxide capture device 1. The control unit 4 controls the operation of devices used for carbon dioxide adsorption and desorption in module 2, such as driving and stopping. The control unit 4 selectively controls the timing of supplying a heat transfer medium to module 2 to provide heating and cooling, so that module 2 can repeatedly perform adsorption and desorption in a time series.
[0040] The devices controlled by the control unit 4 include the aforementioned heat source 21, three-way valve 50, and circulating water pump (not shown). Although not shown, other devices controlled by the control unit 4 include valves for opening and closing piping to introduce and discharge gases such as air to module 2, circulation fans for circulating gases such as air in piping within module 2, a vacuum pump for reducing the pressure inside module 2 to desorb carbon dioxide from the adsorbent 11, valves for opening and closing piping to discharge and recover carbon dioxide from module 2, a recovery pump for recovering carbon dioxide discharged from module 2, and a desorbed water condenser (intercooler) for separating water discharged along with carbon dioxide from carbon dioxide. Of these devices controlled by the control unit 4, those requiring cooling are referred to as auxiliary equipment.
[0041] The control unit 4 is, for example, a computer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc. The control unit 4 may consist of one unit or multiple units. The control unit 4 may also be configured using electrical circuits such as relays.
[0042] In the carbon dioxide recovery device 1, the cold water stored in the cold water tank 22 is supplied to module 2 (adsorbent 11). The cold water stored in the cold water tank 22 is also supplied to the auxiliary equipment 61 and used to cool these auxiliary equipment 61.
[0043] The memory unit 5 stores the temperature conditions, which will be described later. The temperature conditions are read out to the control unit 4 during the adsorption process (cooling process), the first cooling process, and the second cooling process. Examples of temperature conditions include the first temperature condition T1 and the second temperature condition T2. Details of these will be described later.
[0044] The low-temperature water cooling switching mechanism (low-temperature heat transfer medium cooling switching mechanism) 6 includes a cooling switching line 60, an auxiliary device 61, an auxiliary device cooling pump 62, an auxiliary device connection switching valve 63, and a temperature sensor 64.
[0045] The supplemental cooling switching line 60 is connected to the low-temperature water tank 22. The supplemental cooling switching line 60 is connected to the outlet-side flow path 14. The supplemental cooling switching line 60 is connected to the outlet-side flow path 14 between module 2 and the three-way valve 50b. The supplemental cooling switching line 60 connects the low-temperature water tank 22 and the auxiliary equipment 61. The supplemental cooling switching line 60 connects the low-temperature water tank 22 and the auxiliary equipment cooling pump 62. The supplemental cooling switching line 60 connects the auxiliary equipment 61 and the auxiliary equipment cooling pump 62. An auxiliary equipment connection switching valve 63 is connected to the supplemental cooling switching line 60. The supplemental cooling switching line 60 branches between the auxiliary equipment 61 and the auxiliary equipment connection switching valve 63 and is connected to the auxiliary equipment cooling pump 62.
[0046] The auxiliary equipment 61 consists of various devices that generate heat when in operation, such as the vacuum pump, desorbed water condenser, water pump, circulation fan, and recovery pump mentioned above. The auxiliary equipment 61 can be cooled by supplying it with cold water stored in the cold water tank 22. The cold water that has cooled the auxiliary equipment 61 returns to the cold water tank 22 via the auxiliary cooling switching line 60. The auxiliary equipment 61 may also be connected to an equipment heat recovery circuit that is connected to the auxiliary cooling switching line 60 to cool the auxiliary equipment 61 and raise the temperature of the heat transfer medium.
[0047] The auxiliary cooling pump 62 can supply cold water from the cold water tank 22 to the auxiliary equipment 61. The auxiliary cooling switching line 60, which is downstream of the auxiliary cooling pump 62, is connected between the auxiliary connection switching valve 63 and the auxiliary equipment 61. The auxiliary cooling pump 62 is connected to the control unit 4. The auxiliary cooling pump 62 is driven and controlled by the control unit 4. The auxiliary cooling pump 62 can have the same configuration as the circulating water pump for the cold water supply line 31.
[0048] The auxiliary equipment connection switching valve 63 is located downstream of module 2, on the supplemental cooling switching line 60 that branches off from the outlet-side flow path 14. The auxiliary equipment connection switching valve 63 can switch between the low-temperature water discharged from module 2 and the low-temperature water return line 32 and the supplemental cooling switching line 60. The auxiliary equipment connection switching valve 63 is connected to the supplemental cooling switching line 60 that branches off from the outlet-side flow path 14 between module 2 and the three-way valve 50b. The auxiliary equipment connection switching valve 63 is connected to the control unit 4. The switching drive of the auxiliary equipment connection switching valve 63 is controlled by the control unit 4. The flow rate of the auxiliary equipment connection switching valve 63 may be adjustable. When the auxiliary equipment connection switching valve 63 is closed, the low-temperature water in the outlet-side flow path 14 flows from module 2 to the three-way valve 50b. When the auxiliary equipment connection switching valve 63 is closed and the auxiliary equipment cooling pump 62 is driven, the low-temperature water in the auxiliary cooling switching line 60 can circulate between the low-temperature water tank 22 and the auxiliary equipment 61.
[0049] The temperature sensor 64 is installed near the auxiliary component 61. The temperature sensor 64 measures the ambient temperature around the auxiliary component 61. The temperature sensor 64 measures the waste heat environment temperature around the auxiliary component 61. The temperature sensor 64 outputs the measurement result to the control unit 4. The waste heat environment temperature around the auxiliary component 61 measured by the temperature sensor 64 is the ambient temperature around the auxiliary component 61. The temperature sensor 64 may also be installed around the intake port of the gas drawn into the module 2 or in the flow path of the drawn gas. In this case, the temperature sensor 64 measures the temperature of the gas drawn into the module 2.
[0050] <Carbon Dioxide Recovery> Next, the control by the control unit 4 for carbon dioxide recovery will be explained. The carbon dioxide recovery device 1 alternately performs an adsorption process in which gas such as the outside atmosphere is drawn into the adsorbent material 11 in the module 2 and carbon dioxide in the gas is adsorbed, and a desorption process in which carbon dioxide adsorbed on the adsorbent material 11 is desorbed. The desorbed carbon dioxide is stored in a carbon dioxide tank (not shown), thereby removing and recovering carbon dioxide from the air.
[0051] The adsorption process involves adsorbing carbon dioxide onto the adsorbent material 11 within module 2. During the adsorption process, the control unit 4 controls the three-way valves 50a and 50b of the heat exchanger 3 to a low-temperature water connection state, and low-temperature water flows through module 2 to cool the adsorbent material 11 within module 2. The adsorption process also serves as a cooling process for module 2. The control unit 4 operates a circulation fan (not shown) to draw in a gas containing carbon dioxide (for example, the outside atmosphere). The drawn-in gas passes through the adsorbent material 11 within module 2. At this time, the temperature inside the cooled module 2 is, for example, the same as the ambient temperature, and the carbon dioxide in the drawn-in gas is adsorbed onto the adsorbent material 11. Gases other than carbon dioxide, such as nitrogen and oxygen, are exhausted to the outside of the carbon dioxide recovery device 1.
[0052] In the adsorption process (cooling process), the cold water from the cold water tank 22 is supplied to the module 2 as cooling water from the cold water supply line 31 via the three-way valve 50a. The cold water that has cooled the module 2 returns to the cold water tank 22 via the outlet flow path 14, the three-way valve 50b, and the cold water double line 32.
[0053] During the adsorption process (cooling process), the auxiliary equipment 61 is also cooled simultaneously by the low-temperature water cooling switching mechanism 6. During the cooling process of the auxiliary equipment 61, the auxiliary equipment connection switching valve 63 is selectively opened and closed.
[0054] The cooling process for module 2 with the auxiliary equipment connection switching valve 63 closed is the first cooling process, which will be described later. In the first cooling process, cooling water from the low-temperature water tank 22 is supplied to the auxiliary equipment 61 through the auxiliary cooling switching line 60. The cooling water from the low-temperature water tank 22 is supplied to the auxiliary equipment 61 by the operation of the auxiliary equipment cooling pump 62. The low-temperature water that has cooled the auxiliary equipment 61 returns to the low-temperature water tank 22 through the auxiliary cooling switching line 60. The cooling process for module 2 with the auxiliary equipment connection switching valve 63 open is the second cooling process, which will be described later. In the second cooling process, the temperature sensor 64 measures the ambient temperature (outside air temperature) around the auxiliary equipment 61. In response to the rise or fall in temperature around the auxiliary equipment 61, the control unit 4 controls the auxiliary equipment cooling pump 62 to increase or decrease the amount of low-temperature water (cooling water) supplied from the low-temperature water tank 22 to the auxiliary equipment 61.
[0055] The desorption process is a process of desorbing carbon dioxide from the adsorbent 11 in module 2. In the desorption process, the control unit 4 operates a vacuum pump (not shown) to draw air into the inside of module 2, reducing the pressure to a vacuum or near-vacuum state. The control unit 4 also appropriately controls the operation of the three-way valves 50a and 50b of the heat exchanger 3 so that the heat transfer medium of the heat exchanger 3 flows through module 2, supplying thermal energy and raising the temperature of the adsorbent 11 in module 2. Through the temperature rise control of the adsorbent 11 by the control unit 4, the adsorbent 11 is heated to a predetermined temperature (for example, 80°C) sufficient for the desorption process, and the carbon dioxide adsorbed on the adsorbent 11 is desorbed. In addition, in the desorption process, the control unit 4 opens a valve provided in the piping for carbon dioxide recovery, and a recovery pump for carbon dioxide recovery is operated so that the carbon dioxide desorbed in module 2 is stored in a carbon dioxide tank (not shown). During the desorption process, the auxiliary equipment 61 is simultaneously cooled by the low-temperature water cooling switching mechanism 6. The cooling of the auxiliary equipment 61 in the desorption process is carried out in the same manner as the first cooling of the auxiliary equipment 61 in the adsorption process.
[0056] Next, a detailed temperature control of the low-temperature water auxiliary cooling switching mechanism 6 implemented by the control unit 4 in the cooling step of the auxiliary device 61 will be described. FIG. 2 is a flowchart showing the control of the low-temperature water auxiliary cooling switching mechanism 6 implemented by the control unit 4 in the cooling step.
[0057] As shown in FIG. 2, in the cooling step of the module 2, the control unit 4 closes the auxiliary device connection switching valve 63, and supplies low-temperature water from the low-temperature water tank 22 to the auxiliary device 61 directly via the auxiliary cooling switching line 60 in a first cooling step (step S21), and opens the auxiliary device connection switching valve 63, and supplies low-temperature water from the low-temperature water tank 22 to the auxiliary device 61 via the module 2 in a second cooling step (step S22), and selectively implements either one of the first cooling step and the second cooling step. In the control unit 4, implementation of the first cooling step or the second cooling step is selected according to temperature conditions. Hereinafter, the cooling control of the auxiliary device 61 will be specifically described along the flowchart of FIG. 2.
[0058] When the cooling step of the module 2 is started, the control unit 4 acquires the actual temperature T of the module 2 measured by the temperature sensor 12 ＭＭ (hereinafter referred to as measured module temperature T ＭＭ ), and compares it with the temperature T around the auxiliary device 61 measured by the temperature sensor 64 ｏｕｔ (hereinafter referred to as waste heat environment temperature T ｏｕｔ ). The control unit 4 judges switching of cooling for the auxiliary device 61 after these values become equal, that is, after the measured module temperature T ＭＭ becomes equal to the waste heat environment temperature T ｏｕｔ . Here, the waste heat environment temperature T ｏｕｔ is the outside air temperature. It is considered that the waste heat environment temperature T ｏｕｔ is not significantly affected by the waste heat from the auxiliary device 61 and substantially maintains room temperature. The waste heat environment temperature T ｏｕｔ fluctuates depending on factors such as seasons. The measured module temperature T ｏｕｔ that has become equal to the waste heat environment temperature T ＭＭ is the temperature T of the gas sucked into the module 2 ｏｕｔ .
[0059] Note that before the cooling process for module 2 begins, module 2 is either stopped or in the detachment process. Therefore, immediately after the cooling process for module 2 begins, the module measurement temperature T ＭＭ and exhaust heat environment temperature T ｏｕｔ This may differ. Immediately after the cooling process of module 2 begins, the module measurement temperature T is after the desorption process. ＭＭ The exhaust heat environment temperature T ｏｕｔ The temperature is often higher than this. Therefore, the first cooling process may be performed before the cooling process for module 2 begins.
[0060] First, in step S11, the control unit 4 determines the exhaust heat environment temperature T ｏｕｔ and the temperature T of the cold water in the cold water tank 22, as measured by the temperature sensor 27. ＬＴ Compare the following: Temperature T of cold water. ＬＴ From the exhaust heat environment temperature T ｏｕｔ If the control unit 4 determines that the difference obtained by subtracting is smaller than the first temperature condition T1, it proceeds to step S21 and performs the first cooling process. Here, the first temperature condition T1 is stored in the memory unit 5 and read by the control unit 4. In step S11, the control unit 4 makes the above temperature difference determination with respect to the first temperature condition T1 stored in the memory unit 5. The first temperature condition T1 may be any value, but for example it may be 5°C.
[0061] In step S11, the control unit 4 determines the exhaust heat environment temperature T ｏｕｔ and the temperature T of cold water ＬＴ This involves a comparison with the ambient temperature T, in other words, determining whether outside air cooling is possible. ｏｕｔ From the temperature of the cold water T ＬＴ If the difference after subtracting is small, meaning that outside air cooling is not possible, the process proceeds to step S21, where the cooling of the auxiliary equipment 61 and the cooling of module 2 are separated into different lines. In other words, the temperature T of the cold water in the cold water tank 22 ＬＴ The exhaust heat environment temperature T ｏｕｔ Because it is close to the source, the heat discharged from the auxiliary equipment 61 is recovered into the low-temperature water tank 22. If the process proceeds to step S21, the following cases are possible.
[0062] • Temperature T of cold water ＬＴ The exhaust heat environment temperature T ｏｕｔ It is close to that. In other words, the temperature T of cold water ＬＴ The temperature is high, and there is excess heat dissipation from the supplemental cooling switching line 60. At the same time, the ambient temperature of the heat dissipation is high. ｏｕｔ The ambient temperature indicated is high, making it impossible to cool the auxiliary equipment 61. Therefore, cooling is not performed by connecting the auxiliary cooling switching line 60 to module 2. • Temperature T of the low-temperature water ＬＴ The exhaust heat environment temperature T ｏｕｔ It is close to that. In other words, the temperature T of cold water ＬＴ The temperature is low, and at the same time, the exhaust heat environment temperature T ｏｕｔ The ambient temperature shown is low. In this case, the temperature T of the cold water is low. ＬＴ If the temperature is too low, the energy efficiency of the heat exchanger 3 will deteriorate, so the sensible heat of the auxiliary equipment 61 is used to raise the temperature of the cold water T ＬＴ It is necessary to increase the temperature. In other words, the sensible heat possessed by the auxiliary equipment 61 is recovered in order to use it as a heat source for the heat source unit 21. For this reason, cooling is not performed by connecting the auxiliary cooling switching line 60 to module 2.
[0063] • Temperature T of cold water ＬＴ The exhaust heat environment temperature T ｏｕｔ It is close to that. In other words, the exhaust heat environment temperature T ｏｕｔ The ambient temperature is high, and cooling of the auxiliary equipment 61 is possible, but it is necessary to recover the sensible heat possessed by the auxiliary equipment 61 in order to use it as a heat source for the heat source unit 21. For this reason, cooling by connecting the auxiliary cooling switching line 60 to module 2 is not performed. • Temperature T of the low-temperature water ＬＴ The exhaust heat environment temperature T ｏｕｔ It is close to that. In other words, the exhaust heat environment temperature T ｏｕｔ The ambient temperature is high, and the auxiliary equipment 61 cannot be cooled.
[0064] In the above case, the process proceeds to step S21 to perform the first cooling process. In the first cooling process performed in step S21, the low-temperature water supplemental cooling switching mechanism 6 closes the auxiliary equipment connection switching valve 63 and drives the auxiliary equipment cooling pump 62, and the waste heat from the auxiliary equipment 61 is recovered into the low-temperature water tank 22 via the supplemental cooling switching line 60. In the low-temperature water tank 22, the low-temperature water in the low-temperature water tank 22 is cooled via the heat source 21, and the temperature of the high-temperature water in the high-temperature water tank 23 is raised. In step S21, the heat exchanger 3 drives the circulating water pump to flow low-temperature water from the low-temperature water tank 22 towards the module 2, and the module 2 cooling process is performed. In this case, the waste heat ambient temperature T ｏｕｔ and the temperature T of cold water ＬＴ Although the difference is small, it falls within a predetermined range, thus suppressing or preventing the operation of the heat source 21 from being disrupted due to the temperature of the low-temperature water.
[0065] On the other hand, in step S11, the control unit 4 determines the temperature T of the cold water. ＬＴ From the exhaust heat environment temperature T ｏｕｔ If the difference obtained by subtracting is determined to be greater than the first temperature condition T1, the process proceeds to step S12. In step S12, the control unit 4 determines that the temperature T of the low-temperature water in the low-temperature water tank 22, measured by the temperature sensor 27, is greater than the first temperature condition T1. ＬＴ However, it is determined whether or not it is greater (higher) than the second temperature condition T2. The second temperature condition T2 is a reference value for whether or not there is excess exhaust heat. That is, the second temperature condition T2 is a reference value for whether or not cooling is possible by connecting the supplemental cooling switching line 60 to module 2. In step S12, the control unit 4 makes the above determination on the second temperature condition T2 stored in the storage unit 5. The second temperature condition T2 may be any value, but for example it may be 25°C. Then, the control unit 4 determines whether the temperature T of the low-temperature water ＬＴ If it is determined that the temperature is lower than the second temperature condition T2, the process proceeds to step S21 to perform the first cooling process. In this case, the following situations are possible when proceeding to step S21.
[0066] • Temperature T of cold water ＬＴ The exhaust heat environment temperature T ｏｕｔ It is relatively high compared to the temperature T of cold water.ＬＴ The exhaust heat from the supplemental cooling switching line 60 is high enough that there is excess heat. At the same time, the exhaust heat ambient temperature T ｏｕｔ The ambient temperature shown is high, but it is within the range where the auxiliary equipment 61 can be cooled. However, the temperature T of the cold water ＬＴ Since the temperature is still too low, the energy efficiency of the heat exchanger 3 deteriorates, so the sensible heat of the auxiliary equipment 61 is used to raise the temperature of the low-temperature water T ＬＴ The temperature needs to be increased. In other words, the sensible heat possessed by the auxiliary equipment 61 is recovered in order to use it as a heat source for the heat source unit 21. For this reason, cooling is not performed by connecting the auxiliary cooling switching line 60 to module 2. • Temperature T of the low-temperature water ＬＴ The exhaust heat environment temperature T ｏｕｔ It is relatively high compared to the temperature T of cold water. ＬＴ The exhaust heat from the supplemental cooling switching line 60 is high enough that there is excess heat. At the same time, the exhaust heat ambient temperature T ｏｕｔ The ambient temperature shown is high, making it impossible to cool the auxiliary equipment 61. Therefore, cooling is not performed by connecting the auxiliary cooling switching line 60 to module 2.
[0067] In the above case, proceed to step S21 and perform the first cooling process.
[0068] On the other hand, in step S12, the control unit 4 determines the temperature T of the cold water. ＬＴ If it is determined that the temperature is higher than the second temperature condition T2, the process proceeds to step S22 to perform the second cooling process. If the control unit 4 determines that outside air cooling is possible, the process proceeds to step S22, and the auxiliary cooling switching line 60 for cooling the auxiliary equipment 61 is switched to the line for cooling the module 2 which is currently adsorbing. In other words, the heat discharged from the auxiliary equipment 61 is discharged to the outside via the module 2 through the low-temperature water tank 22. In this cooling process where the auxiliary cooling switching line 60 is connected to the module 2, i.e., the second cooling process, no heat recovery is performed because the sensible heat of the auxiliary equipment 61 is released into the outside air. The following cases are possible when proceeding to step S22.
[0069] • Temperature T of cold water ＬＴ The exhaust heat environment temperature T ｏｕｔ It is sufficiently high compared to that. In other words, the temperature T of cold water ＬＴTherefore, there is excess heat dissipated from the supplemental cooling switching line 60. At the same time, the heat dissipation ambient temperature T ｏｕｔ The ambient temperature shown is high, but it is within a range where the auxiliary equipment 61 can be cooled.
[0070] In the above case, the process proceeds to step S22 to perform the second cooling process. In the second cooling process performed in step S22, the low-temperature water supplemental cooling switching mechanism 6 opens the auxiliary equipment connection switching valve 63 to stop the auxiliary equipment cooling pump 62, and the waste heat from the auxiliary equipment 61 is discharged to the outside in module 2 via the low-temperature water through the low-temperature water tank 22 via the supplemental cooling switching line 60. At the same time, the waste heat from the auxiliary equipment 61 is discharged via the low-temperature water tank 22 via the low-temperature water tank 21 via the supplemental cooling switching line 60 to raise the temperature of the high-temperature water in the high-temperature water tank 23. The low-temperature water circulates sequentially through the auxiliary equipment 61, supplemental cooling switching line 60, low-temperature water tank 22, low-temperature water supply line 31, three-way valve 50a, inlet side flow path 13, module 2, low-temperature water return line 32, outlet side flow path 14, auxiliary equipment connection switching valve 63, and supplemental cooling switching line 60 as a single line, driven by the circulation water pump. In the second cooling process, the temperature of the cold water in the cold water tank 22 is high, which can suppress or prevent the operation of the heat source 21 from being disrupted due to the temperature of the cold water. After the cooling process to cool module 2, a desorption process and an adsorption process are carried out in order.
[0071] Note that the temperature T of the low-temperature water in the low-temperature tank 22 during the first cooling process. ＬＴ For example, the temperature T of the low-temperature water in the low-temperature tank 22 during the second cooling process. ＬＴ The temperature T of the low-temperature water in the low-temperature tank 22 during the first cooling process is... ＬＴ It is higher than that, for example, 40°C. The temperature of the high-temperature water in the high-temperature water tank 23 during the desorption process is, for example, 80°C. The target temperature of module 2 during the desorption process is, for example, 80°C. In the first and second cooling processes, the temperature of the low-temperature water supplied to the auxiliary equipment 61 is, for example, 30°C. In the first and second cooling processes, the temperature of the low-temperature water returned from the auxiliary equipment 61 to the low-temperature tank 22 is, for example, 35°C.
[0072] Furthermore, the operating state of the circulating water pump can be lower in the first cooling process compared to the second cooling process. In other words, in the second cooling process, the operating state of the circulating water pump can be higher than in the first cooling process.
[0073] As described above, in the carbon dioxide recovery apparatus 1 according to this embodiment, when the module 2 performs the adsorption process, the control unit 4 supplies cold water from the cold water tank 22 to the module 2 and selectively performs a first cooling process in which cold water is supplied from the cold water tank 22 to the auxiliary equipment 61 on a separate line, and a second cooling process in which cold water is supplied from the cold water tank 22 to the auxiliary equipment 61 via the module 2 on the same line.
[0074] The control unit 4 then controls the temperature T of the cold water in the cold water tank 22. ＬＴ From the exhaust heat environment temperature T ｏｕｔ If the difference obtained by subtracting is smaller than the first temperature condition T1, the first cooling process is performed, and the temperature of the low-temperature water in the low-temperature water tank 22 T ＬＴ From the exhaust heat environment temperature T ｏｕｔ The difference obtained by subtracting is greater than that of the first temperature condition T1, and the temperature of the cold water T ＬＴ The first cooling process is performed when the temperature of the cold water in the cold water tank 22 is smaller than the second temperature condition T2. ＬＴ From the exhaust heat environment temperature T ｏｕｔ The difference obtained by subtracting is greater than that of the first temperature condition T1, and the temperature of the cold water T ＬＴ The second cooling process is performed when the second temperature condition T2 is greater than the second temperature condition T2.
[0075] Therefore, the exhaust heat environment temperature T fluctuates due to seasonal factors. ｏｕｔ Without being affected, when performing the cooling process of module 2, the temperature of the cold water in the cold water tank 22 T ＬＴ In contrast, the cooling of the auxiliary equipment 61 can be performed in a predetermined process. This makes it possible to suppress the amount of energy used in cooling the module 2 by the heat exchanger 3.
[0076] Heating module 2 with cold water from cold water tank 22 is useful from an energy-saving perspective when the outside temperature is low (for example, 5°C) such as in winter. When the outside temperature is low, the temperature T of the cold water in cold water tank 22 depends on the operating conditions of the heat source 21. ＬＴ Although it fluctuates with respect to the ambient temperature, it is not affected by this fluctuation range, and the exhaust heat environment temperature (ambient temperature) T ｏｕｔ The measurement temperature T of module 2 in the adsorption process is approximately the same. ＭＭ Without being affected by fluctuations, the module 2 can be sufficiently cooled by the low-temperature water in the low-temperature water tank 22.
[0077] Furthermore, in the carbon dioxide recovery apparatus 1 according to this embodiment, when the module 2 performs the adsorption process and the desorption process, the waste heat environment temperature T fluctuates due to seasonal factors. ｏｕｔ Without being affected by the external factors, the control unit 4, which performs the cooling process for the auxiliary equipment 61, supplies low-temperature water from the low-temperature water tank 22 directly to the auxiliary equipment 61, or via module 2. This allows the auxiliary equipment 61 to be cooled by a low-temperature heat transfer medium without interfering with the operation of the heat source unit 21.
[0078] Temperature T of the cold water in the cold water tank 22 ＬＴ From the exhaust heat environment temperature T ｏｕｔ If the difference obtained by subtracting is greater than the first temperature condition T1, and the temperature of the cold water in the cold water tank 22 is T ＬＴ Performing the second cooling process (supplying cold water from the cold water tank 22 to the auxiliary equipment 61 via module 2) only when the temperature of the cold water is greater than the second temperature condition T2 is particularly useful when the outside temperature is low (for example, 5°C), such as in winter. This point will be explained below. When the outside temperature is high, such as in summer, the amount of heat dissipated into the outside air from the various auxiliary equipment is small, so much of the heat discharged from module 2 and auxiliary equipment 61 (waste heat) is recovered by the cold water supplied from the cold water tank 22. For this reason, the temperature of the cold water in the cold water tank 22 T ＬＴ The temperature becomes relatively high. Therefore, the temperature T of the cold water in the cold water tank 22 ＬＴ The heat dissipated from module 2 and auxiliary equipment 61 reduces the ambient temperature T. ｏｕｔis often higher than that.
[0079] On the other hand, when the outside air temperature is low, such as in winter, a large amount of heat is dissipated from the auxiliary device 61 to the outside air. Therefore, among the heat (waste heat) discharged from the module 2 and the auxiliary device 61, the amount of heat recovered by the low-temperature water supplied from the low-temperature water tank 22 is small. For this reason, the temperature T of the low-temperature water in the low-temperature water tank 22 ＬＴ becomes relatively low. Thereby, the temperature T of the low-temperature water in the low-temperature water tank 22 ＬＴ is highly likely to reach a temperature close to the waste heat environment temperature T ｏｕｔ . From the above, it is useful to implement the second cooling step only when the temperature T of the low-temperature water in the low-temperature water tank 22 ＬＴ satisfies the above condition with respect to the waste heat environment temperature T ｏｕｔ , and implement the first cooling step otherwise.
[0080] In other words, in the carbon dioxide capture device 1 according to the present embodiment: - the outside air temperature is lower than the low-temperature water temperature T ＬＴ ; - there is sufficient surplus waste heat on the side of the low-temperature water temperature T ＬＴ . When these two conditions are satisfied, the second cooling step is implemented, and the first cooling step is implemented otherwise. This satisfies the following two requirements: - to increase the low-temperature water temperature T ＬＴ and reduce the temperature difference between the low-temperature water temperature T ＬＴ and the high-temperature water temperature, so as to reduce the energy consumption of the heat exchange device 3; - to keep the low-temperature water temperature T ＬＴ low, so as to maintain high cooling efficiency for the auxiliary device 61. Thereby, reduction of energy consumption and protective cooling of the auxiliary device 61 can be achieved at the same time. In addition, when the module measurement temperature T ＭＭ and the waste heat environment temperature T ｏｕｔ are different, the cooling step can be performed by replacing the first temperature condition T1 with the third temperature condition and replacing the second temperature condition T2 with the fourth temperature condition.
[0081] The embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments and modifications. In addition, the effects described in the above embodiments are merely enumerations of preferred effects, and the present invention is not limited to those described in the above embodiments.
[0082] For example, the carbon dioxide recovery device 1 may comprise multiple modules 2. In this case, for example, the low-temperature water line 30 and the high-temperature water line 40 may be branched and configured to be connected in parallel to multiple modules 2. In this case, the low-temperature water cooling switching mechanism 6 can be connected to any module 2, provided that the necessary auxiliary equipment 61 can be cooled. Furthermore, the low-temperature water cooling switching mechanism 6 can be provided for each of the multiple auxiliary equipment 61, enabling simultaneous cooling.
[0083] The present invention is not limited to being applied to carbon dioxide recovery devices, but may also be applied to gas recovery devices that recover a specific gas (specific gas) contained in any gas (mixed gas). In this case, the adsorbent placed in the module to adsorb the specific gas only needs to have the property of adsorbing the specific gas at low temperatures and desorbing (releasing) the specific gas at high temperatures and when the concentration of the specific gas in the surrounding environment is low.
[0084] 1...Carbon dioxide capture device 2...Module 3...Heat exchange device 4...Control unit 5...Memory unit 11...Adsorbent 21...Heat source 22...Low temperature water tank (low temperature heat transfer fluid tank) 23...High temperature water tank (high temperature heat transfer fluid tank) 6...Low temperature water supplemental cooling switching mechanism (low temperature heat transfer fluid supplemental cooling switching mechanism) 61...Auxiliary equipment 62...Auxiliary equipment cooling pump 63...Auxiliary equipment connection switching valve T1...First temperature condition T2...Second temperature condition T ＬＴ ...Temperature T of the cold water in the cold water tank 22 ｏｕｔ ...Exhaust heat environmental temperature T ＭＭ ...module measurement temperature
Claims
1. A module having an adsorbent inside, which performs an adsorption step of drawing a gas containing carbon dioxide onto the adsorbent to adsorb the carbon dioxide, and a desorption step of heating the area around the adsorbent to desorb the carbon dioxide from the adsorbent; a heat exchanger having a heat pump type heat source that heats a high-temperature heat transfer medium and cools a low-temperature heat transfer medium, a high-temperature heat transfer medium tank that stores the high-temperature heat transfer medium heated by the heat source, and a low-temperature heat transfer medium tank that stores the low-temperature heat transfer medium cooled by the heat source, which performs a heating step of supplying the high-temperature heat transfer medium to heat the module and a cooling step of supplying the low-temperature heat transfer medium to cool the module; an auxiliary component capable of supplying the low-temperature heat transfer medium for cooling; an auxiliary component connection switching valve that can switch the low-temperature heat transfer medium returning from the module to the low-temperature heat transfer medium tank to the auxiliary component; and a control unit, wherein the control unit, when performing the cooling step of the module, A carbon dioxide recovery device, wherein if the difference between the temperature of the low-temperature heat transfer medium in the low-temperature heat transfer medium tank and the exhaust heat environment temperature around the auxiliary equipment is smaller than a first temperature condition, the auxiliary equipment connection switching valve is switched to perform a first cooling step in which the low-temperature heat transfer medium is returned from the module to the low-temperature heat transfer medium tank and the low-temperature heat transfer medium is supplied from the low-temperature heat transfer medium tank to the auxiliary equipment; and if the difference between the temperature of the low-temperature heat transfer medium in the low-temperature heat transfer medium tank and the exhaust heat environment temperature around the auxiliary equipment is larger than the first temperature condition, the auxiliary equipment connection switching valve is switched to perform a second cooling step in which the low-temperature heat transfer medium is returned from the module to the low-temperature heat transfer medium tank via the auxiliary equipment, or the first cooling step is performed.
2. When the control unit performs the cooling step of the module, it performs the second cooling step if the difference between the temperature of the low-temperature heat medium in the low-temperature heat medium tank and the exhaust heat environment temperature around the auxiliary equipment is greater than the first temperature condition, and the temperature of the low-temperature heat medium in the low-temperature heat medium tank is equal to or greater than the second temperature condition; and it performs the first cooling step if the difference between the temperature of the low-temperature heat medium in the low-temperature heat medium tank and the exhaust heat environment temperature around the auxiliary equipment is greater than the first temperature condition, and the temperature of the low-temperature heat medium in the low-temperature heat medium tank is equal to or less than the second temperature condition, the carbon dioxide recovery apparatus according to claim 1.
3. A module having an adsorbent inside, which performs an adsorption step of drawing a gas containing carbon dioxide onto the adsorbent to adsorb the carbon dioxide, and a desorption step of heating the area around the adsorbent to desorb the carbon dioxide from the adsorbent; a heat exchanger having a heat pump type heat source that heats a high-temperature heat transfer medium and cools a low-temperature heat transfer medium, a high-temperature heat transfer medium tank that stores the high-temperature heat transfer medium heated by the heat source, and a low-temperature heat transfer medium tank that stores the low-temperature heat transfer medium cooled by the heat source, which performs a heating step of supplying the high-temperature heat transfer medium to heat the module and a cooling step of supplying the low-temperature heat transfer medium to cool the module; an auxiliary component capable of supplying the low-temperature heat transfer medium for cooling; an auxiliary component connection switching valve that can switch the low-temperature heat transfer medium returning from the module to the low-temperature heat transfer medium tank to the auxiliary component; and a control unit, wherein the control unit, when performing the cooling step of the module, A carbon dioxide recovery device, wherein if the difference between the temperature of the low-temperature heat transfer medium in the low-temperature heat transfer medium tank and the temperature of the gas drawn into the module is smaller than a third temperature condition, the auxiliary equipment connection switching valve is switched to perform a first cooling step in which the low-temperature heat transfer medium is returned from the module to the low-temperature heat transfer medium tank and the low-temperature heat transfer medium is supplied from the low-temperature heat transfer medium tank to the auxiliary equipment; and if the difference between the temperature of the low-temperature heat transfer medium in the low-temperature heat transfer medium tank and the temperature of the gas drawn into the module is larger than the third temperature condition, the auxiliary equipment connection switching valve is switched to perform a second cooling step in which the low-temperature heat transfer medium is returned from the module to the low-temperature heat transfer medium tank via the auxiliary equipment, or the first cooling step.
4. When the control unit performs the cooling step of the module, it performs the second cooling step if the difference between the temperature of the low-temperature heat medium in the low-temperature heat medium tank and the temperature of the gas drawn into the module is greater than the third temperature condition, and the temperature of the low-temperature heat medium in the low-temperature heat medium tank is at or above the fourth temperature condition; and it performs the first cooling step if the difference between the temperature of the low-temperature heat medium in the low-temperature heat medium tank and the temperature of the gas drawn into the module is greater than the third temperature condition, and the temperature of the low-temperature heat medium in the low-temperature heat medium tank is at or below the fourth temperature condition, the carbon dioxide recovery apparatus according to claim 3.
5. A carbon dioxide recovery apparatus according to any one of claims 1 to 4, comprising an auxiliary cooling pump capable of supplying the low-temperature heat transfer medium from the low-temperature heat transfer medium tank to the auxiliary equipment, wherein the control unit drives the auxiliary cooling pump when executing the second cooling step.