JP2010266155A - Carbon dioxide liquefying apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carbon dioxide liquefying apparatus capable of saving energy. <P>SOLUTION: This carbon dioxide liquefying apparatus 1 includes a pressure-increase dehumidifying apparatus 10 for pressure-increase a gas mixture Gm, containing carbon dioxide as the main component and steam for removing moisture; a cooler 21 for cooling the gas mixture Gm by a cooling medium F; a moisture condenser 41; a dehumidifier system 50 for generating a dehumidified carbon dioxide gas Gdh; with the moisture concentration of the gas mixture Gm being reduced to a prescribed concentration; and a carbon dioxide condenser 42 for cooling-condensing the dehumidified carbon dioxide gas Gdh for generating liquefied carbon dioxide Ln. The moisture condenser 41 cools the gas mixture Gm to a prescribed temperature which is higher than the condensing temperature of carbon dioxide, and the moisture in the gas mixture Gm can be condensed. The moisture is removed by the moisture condenser 41, before introducing the gas mixture Gm into the dehumidifier system 50, and a dehumidifying load is thereby reduced in the dehumidifier system 50 and energy is saved. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a carbon dioxide liquefying apparatus, and more particularly to a carbon dioxide liquefying apparatus designed to save energy.

  The total amount of carbon dioxide, one of the greenhouse gases, is on the rise, and global climate change is feared. As an attempt to reduce carbon dioxide emissions into the atmosphere, a technology has been developed in which carbon dioxide separated and recovered from exhaust gas discharged from a thermal power plant or the like is liquefied and stored in the ground or deep sea. As an apparatus for recovering liquid carbon dioxide from a gas containing carbon dioxide, an apparatus for removing moisture from the gas containing carbon dioxide, an apparatus for concentrating carbon dioxide from the dehumidified gas, and an apparatus for compressing the carbon dioxide concentrated gas And what is equipped with the condenser which cools and compresses the compressed carbon dioxide gas to -20 degrees C or less is well-known (for example, refer patent document 1).

JP-A-4-359785 (paragraph 0005, FIG. 3 etc.)

  Since the carbon dioxide liquefaction apparatus consumes a great deal of energy, it is useful to take energy saving measures.

  An object of this invention is to provide the carbon dioxide liquefying apparatus aiming at energy saving in view of the above-mentioned subject.

  In order to achieve the above object, the carbon dioxide liquefying apparatus according to the first aspect of the present invention introduces a mixed gas Gm containing carbon dioxide as a main component and containing water vapor, for example, as shown in FIG. Pressure increase dehydration apparatus 10 for increasing the pressure to a first predetermined pressure P1 (for example, see FIG. 2) less than the critical pressure of carbon dioxide and removing a part of water in the mixed gas Gm; A cooler 21 that cools the mixed gas Gm with a cooling medium F that retains cold heat derived from air or water existing in a natural environment; and the mixed gas Gm that has passed through the cooler 21 is a first predetermined gas A water condenser 41 for condensing the water in the mixed gas Gm by cooling to a predetermined temperature higher than the condensation temperature of carbon dioxide at a pressure P1 (for example, see FIG. 2); and mixing after passing through the water condenser 41 In gas Gm A dehumidifying device 50 for removing moisture, which generates a dehumidified carbon dioxide gas Gdh in which the moisture concentration in the mixed gas Gm is reduced to a predetermined concentration; cooling and condensing the dehumidified carbon dioxide gas Gdh as a main component Includes a carbon dioxide condenser 42 that generates liquefied carbon dioxide Ln, which is a condensate of carbon dioxide.

  If comprised in this way, the mixed gas was cooled to the predetermined | prescribed temperature higher than the condensation temperature of the carbon dioxide in a 1st predetermined | prescribed pressure, the moisture condenser which condenses the water | moisture content in mixed gas, and the moisture condenser passed. Since the dehumidifying device that removes the water in the later mixed gas is provided, it is possible to reduce the dehumidifying load in the dehumidifying device and to save energy.

  Moreover, the carbon dioxide liquefying apparatus according to the second aspect of the present invention is, for example, as shown in FIG. 1, in the carbon dioxide liquefying apparatus 1 according to the first aspect of the present invention described above, a mixed gas is added to the water condenser 41. Cooling fluid flow paths 45 and 46 for introducing and deriving the cooling fluid C for cooling Gm; Introducing cooling heat amount adjusting means 48 and 49 for adjusting the cooling heat amount per unit time of the cooling fluid C introduced into the moisture condenser 41 And a temperature detector 65 for detecting the temperature of the mixed gas Gm derived from the water condenser 41; and controlling the introduction cold heat amount adjusting means 49 so that the temperature detected by the temperature detector 65 becomes the predetermined temperature. And a control device 80.

  If comprised in this way, it can suppress that the condensation of the carbon dioxide content in mixed gas resulting from mixed gas falling from predetermined temperature generate | occur | produces before mixed gas flows in into a dehumidifier. .

  Further, for example, as shown in FIG. 1, the carbon dioxide liquefying apparatus according to the third aspect of the present invention is a liquefied carbon dioxide in the carbon dioxide liquefying apparatus 1 according to the first aspect or the second aspect of the present invention. A pump 28 for increasing Ln to a second predetermined pressure P2 (for example, see FIG. 2) exceeding the critical pressure of carbon dioxide; and supercritical pressure liquefied carbon dioxide Lp which is liquefied carbon dioxide Ln boosted by the pump 28. And a mixed gas Gm before being introduced into the moisture condenser 41, and a heat exchanger 30 for performing heat exchange.

  If comprised in this way, since the heat exchanger which performs heat exchange with supercritical pressure liquefied carbon dioxide and the mixed gas before being introduced into the moisture condenser is provided, the mixed gas before being introduced into the moisture condenser is super Precooling with critical pressure liquefied carbon dioxide can reduce the refrigeration load of the water condenser, thereby saving energy.

  Moreover, the carbon dioxide liquefying apparatus according to the fourth aspect of the present invention is, for example, as shown in FIG. 3B, the dioxide dioxide according to any one of the first to third aspects of the present invention. In the carbon liquefaction apparatus 1B, the dehumidifying device regenerates the moisture deprivation medium 55, which deprives moisture, deprives the moisture in the mixed gas Gm, and the moisture deprivation medium Q, which heats the moisture deprivation medium Q and evaporates the moisture from the moisture deprivation medium Q. The regenerator 57 receives the heat H discharged from the pressurization dehydrator 10 (see, for example, FIG. 1) and heats the moisture deprivation medium Q.

  If comprised in this way, reproduction | regeneration of a water | moisture-content removal medium can be performed with the waste heat of a pressure | voltage rise dehydration apparatus, and energy saving can be aimed at.

  According to the present invention, the mixed gas is cooled to a predetermined temperature higher than the condensation temperature of carbon dioxide at the first predetermined pressure to condense the water in the mixed gas, and the moisture condenser is passed. Since the dehumidifying device that removes the water in the later mixed gas is provided, it is possible to reduce the dehumidifying load in the dehumidifying device and to save energy.

It is a systematic diagram which shows schematic structure of the carbon dioxide liquefying apparatus which concerns on embodiment of this invention. It is a ph diagram of carbon dioxide showing the state of carbon dioxide in a mixed gas. It is a partial systematic diagram which shows schematic structure around the dehumidifier of the carbon dioxide liquefying apparatus which concerns on the modification of embodiment of this invention. (A) shows a first modification, and (b) shows a second modification.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or similar members are denoted by the same or similar reference numerals, and redundant description is omitted.

  First, a carbon dioxide liquefying apparatus 1 according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a system diagram showing a schematic configuration of the carbon dioxide liquefying apparatus 1. The carbon dioxide liquefying apparatus 1 includes a pressure increase dehydration apparatus 10 as a pressure increase apparatus, a fourth cooler 21 as a cooler, a cold heat recovery apparatus 30 as a heat exchanger, moisture, from upstream to downstream in the flow direction of the mixed gas Gm. A condenser 41, a fourth gas-liquid separator 25, a dehumidifier 50 as a dehumidifier, and a carbon dioxide condenser 42 as a condenser are provided, and a carbon dioxide condenser is provided downstream of the carbon dioxide condenser 42. A booster pump 28 is further provided as a pump for boosting the liquefied carbon dioxide Ln produced at 42. Further, the carbon dioxide liquefying apparatus 1 includes a control device 80 that controls the operation.

  The mixed gas Gm is a form of carbon dioxide-containing gas containing carbon dioxide as a main component, and also contains water vapor. In the present embodiment, the mixed gas Gm is generated by absorbing the carbon dioxide gas in the exhaust gas after the fuel is burned into the absorbent, guiding it to the regenerator, and regenerating the absorbent with the regenerator. In the following description, it is assumed that the gas is a mixture of carbon dioxide and water vapor.

  The pressurizing and dehydrating device 10 is a device that pressurizes the mixed gas Gm. The pressurization dehydrator 10 is also a dehydrator that removes condensed water generated by cooling to reduce the specific enthalpy that increases when the mixed gas Gm is pressurized. The pressurized dehydration apparatus 10 includes a first cooler 11C that cools the introduced mixed gas Gm, a first gas-liquid separator 11S that separates condensed water from the mixed gas Gm, and a mixed gas Gm from which condensed water has been separated. The first compressor 11 </ b> P for boosting the pressure has a first pressurizing and dehydrating unit 11 configured in this order. Furthermore, in the subsequent stage of the first pressurizing and dehydrating unit 11, a first cooler 11C, a first gas-liquid separator 11S, a second cooler 12C corresponding to the first compressor 11P, a second gas-liquid separator 12S, The second pressurization and dehydration unit 12, the third cooler 13C, the third gas-liquid separator 13S, and the third compressor 13P are arranged in this order. The third pressurizing and dehydrating unit 13 is configured. The second pressurization dehydration unit 12 is configured to pressurize the mixed gas Gm to a pressure higher than that of the first pressurization dehydration unit 11. The third pressurizing and dehydrating unit 13 is provided in the subsequent stage of the second pressurizing and dehydrating unit 12 and is configured to pressurize the mixed gas Gm to a higher pressure than the second pressurizing and dehydrating unit 12. In addition, when condensed water accumulates in the lower part of each cooler 11C, 12C, 13C, condensed water may be extracted also from the lower part of each cooler 11C, 12C, 13C.

  The fourth cooler 21 is a device that cools the mixed gas Gm derived from the pressurization dehydration apparatus 10. The fourth cooler 21 is configured to cool the mixed gas Gm by the cold heat held by the cooling fluid F as a cooling medium. As the cooling fluid F, cooling water cooled to a temperature equal to or higher than the outside air wet bulb temperature by heat exchange with the outside air in the cooling tower, well water, seawater, or the like, or the outside air itself may be used. As described above, the cooling fluid F is a fluid that retains cold energy derived from air or water existing in the natural environment. When the cooling fluid F is a liquid, the fourth cooler 21 has fin tube heat exchange configured such that the cooling fluid F flows inside the finned tube arranged in parallel and the mixed gas Gm flows outside the tube. When the cooling fluid F is a gas, particularly outside air, a plate fin heat exchanger is used, and a configuration in which the mixed gas Gm is flowed into the tube and the outside air is flowed to the plate fin side is preferably used. In the present embodiment, the first cooler 11C, the second cooler 12C, and the third cooler 13C of the pressurizing dehydrator 10 are also configured in the same manner as the fourth cooler 21 and are introduced into the fourth cooler 21. The same cooling fluid F as that used is introduced to cool the mixed gas Gm.

  The cold heat recovery device 30 is a device that performs heat exchange between the mixed gas Gm derived from the fourth cooler 21 and the supercritical pressure liquefied carbon dioxide Lp pressurized by the booster pump 28. Typically, the cold heat recovery unit 30 has a plurality of finned tubes arranged in parallel to flow supercritical pressure liquefied carbon dioxide Lp, which is a liquid, inside, and the mixed gas Gm passes through the outside of the tube. The gas-liquid heat exchanger (fin tube heat exchanger) is configured to perform heat exchange between the mixed gas Gm and the supercritical pressure liquefied carbon dioxide Lp.

  The moisture condenser 41 is a device that cools the mixed gas Gm to a predetermined temperature with the cold heat held by the cold water C as a cold medium having a temperature lower than that of the cooling fluid F. The predetermined temperature is higher than the condensation temperature of carbon dioxide at the partial pressure of the carbon dioxide gas in the mixed gas Gm introduced into the moisture condenser 41 from the viewpoint of avoiding the condensation of the carbon dioxide gas in the mixed gas Gm. A temperature lower than the condensation temperature of water vapor in the partial pressure of water vapor in the mixed gas Gm introduced into the water condenser 41 from the viewpoint of condensing and removing the water in the mixed gas Gm, and a dehumidifier From the viewpoint of reducing the load of 50, it is preferable to set the temperature as low as possible (a temperature at which condensed water can be extracted as much as possible). The cold water C is manufactured (cooled) by the refrigerator 40. The water condenser 41 is typically a finned tube heat exchanger having a configuration similar to that of the cold heat recovery unit 30, and cold water C flows through the finned tube.

  The fourth gas-liquid separator 25 is a device that separates the moisture condensed by the moisture condenser 41 from the mixed gas Gm. By removing the condensed water accompanying the mixed gas Gm by the fourth gas-liquid separator 25, it is possible to reduce the load on the dehumidifier 50 disposed in the subsequent stage. The dehumidifier 50 is a device that removes moisture in the mixed gas Gm to obtain dehumidified carbon dioxide gas Gdh in which the moisture concentration in the mixed gas Gm is reduced to a predetermined concentration. The dehumidifier 50 is typically an adsorption type dehumidifier that adsorbs moisture to an adsorbent that is a solid that easily absorbs moisture, or an absorption type desorber that absorbs moisture to an absorbent that is a liquid that easily absorbs moisture. A dehumidifier is used. In this case, the adsorbent that has adsorbed moisture or the absorbent that has absorbed moisture is regenerated to a state before it is adsorbed or absorbed by being heated later. The predetermined concentration is a water concentration at which the flow of the liquefied carbon dioxide Ln is not inhibited by the generation of hydrate when the dehumidified carbon dioxide gas Gdh is condensed later to form liquefied carbon dioxide Ln. The concentration is several ppm by volume.

  The carbon dioxide condenser 42 is a device that cools the dehumidified carbon dioxide gas Gdh with the cold heat held by the cold water C as the cold medium and condenses it into liquefied carbon dioxide Ln. The cold water C is manufactured by a refrigerator 40 serving as a cold heat source common to the cold water C supplied to the moisture condenser 41. Although the carbon dioxide condenser 42 is simply shown in the figure, a shell and tube type in which a large number of tubes 42t are built in the shell 42b and a multi-pass configuration in the vertical direction is preferable. When the dehumidified carbon dioxide gas Gdh is caused to flow outside the tube 42t in the shell 42b and the cold water C is caused to flow inside the tube 42t, the cold water C is introduced from the lower side of the multipass and led out from the upper part. It becomes easy to supercool the liquefied carbon dioxide Ln. On the other hand, cold water C can be flowed outside the tube 42t in the shell 42b, and dehumidified carbon dioxide gas Gdh can be flowed into the tube 42t. In this case, the dehumidified carbon dioxide gas Gdh is introduced from the upper side of the multipass. Therefore, it is easy to supercool the liquefied carbon dioxide Ln. In the present embodiment, the carbon dioxide condenser 42 will be described as having a structure in which the dehumidified carbon dioxide gas Gdh flows outside the tube 42t in the shell 42b and the cold water C flows inside the tube 42t. A condenser pressure gauge 64 for detecting the pressure of the dehumidified carbon dioxide gas Gdh is provided in the flow path (shell 42b) of the dehumidified carbon dioxide gas Gdh.

  The tube 42 t of the carbon dioxide condenser 42 is connected to the cold water outlet 40 a of the refrigerator 40 through the cold water outgoing pipe 44, so that the supply of cold water C from the refrigerator 40 can be received. The chilled water outgoing pipe 44 is typically connected to a tube 42t that is disposed at the lowest vertical position. The tube 42t disposed on the upper side is connected to one end of the finned tube of the moisture condenser 41 through the cold water transfer pipe 45. The other end of the finned tube of the water condenser 41 is connected to the cold water inlet 40 b of the refrigerator 40 through a cold water return pipe 46. The refrigerator 40 is typically a water-cooled or air-cooled heat source device. A refrigerant (not shown) performs a refrigeration cycle (alternating evaporation and condensation), and the refrigerant is evaporated when the refrigerant evaporates. Is a device that removes (cools) heat from the cold water C passing through. As the refrigerator 40, a general-purpose turbo refrigerator, an absorption refrigerator, a chilling unit, or the like can be used. As the refrigerant that performs the refrigeration cycle of the refrigerator 40, it is preferable to use a refrigerant that can perform the refrigeration cycle with a smaller energy (for example, a low operating pressure) than the pressure of carbon dioxide gas increased by the compressor. . The refrigerator 40 produces chilled water C having a temperature at which the liquefied carbon dioxide Ln generated in the carbon dioxide condenser 42 can be used as a saturated liquid or supercooled liquid (compressed liquid) of carbon dioxide at the pressure in the shell 42b. It is configured to be able to. The refrigerator 40 is configured so that the temperature of the cold water C derived by adjusting the refrigerating capacity can be varied. A cold water bypass pipe 48 that bypasses the cold water C without introducing it into the moisture condenser 41 is connected to the cold water transfer pipe 45 and the cold water return pipe 46. The cold water bypass pipe 48 is provided with a flow rate adjusting valve 49 that can adjust the flow rate of the cold water C flowing inside. The chilled water bypass pipe 48 and the flow rate adjusting valve 49 make it possible to adjust the amount of cold per unit time introduced into the moisture condenser 41, and constitute an introduced cold heat amount adjusting means. Further, the chilled water outgoing pipe 44, the chilled water transition pipe 45, and the chilled water return pipe 46 are each an aspect of the cooling fluid flow path.

  The mixed gas Gm or dehumidified carbon dioxide of the pressurizing dehydrator 10, the fourth cooler 21, the cold heat recovery unit 30, the moisture condenser 41, the fourth gas-liquid separator 25, the dehumidifier 50, and the carbon dioxide condenser 42 described above. The flow paths through which the gas Gdh passes are connected by a gas pipe 61. A gas pipe 61 between the moisture condenser 41 and the fourth gas-liquid separator 25 is provided with a gas thermometer 65 as a temperature detector for detecting the temperature of the mixed gas Gm.

  One end of a liquid pipe 68 for flowing the liquefied carbon dioxide Ln is connected to the lower part, preferably the bottom part, of the shell 42b of the carbon dioxide condenser 42. The other end of the liquid pipe 68 is connected to one end of a finned tube of the cold heat recovery unit 30. A booster pump 28 is inserted into the liquid pipe 68. Connected to the other end of the finned tube of the cold heat recovery unit 30 is a lead-out liquid pipe 69 through which the supercritical pressure liquefied carbon dioxide Lp derived from the cold heat recovery device 30 flows. The supercritical pressure liquefied carbon dioxide Lp flowing through the outlet liquid pipe 69 is typically guided to the ground or the deep sea bottom. A liquid bypass pipe 32 that bypasses the supercritical pressure liquefied carbon dioxide Lp without introducing it into the cold heat recovery unit 30 is connected to the liquid pipe 68 and the outlet liquid pipe 69. The liquid bypass pipe 32 is provided with a flow rate adjustment valve 33 that can adjust the flow rate of the supercritical pressure liquefied carbon dioxide Lp flowing inside. The liquid bypass pipe 32 and the flow rate adjustment valve 33 make it possible to adjust the amount of exchange heat between the mixed gas Gm and the supercritical pressure liquefied carbon dioxide Lp in the cold heat recovery unit 30, and constitute an exchange heat amount adjustment means. . The lead-out liquid pipe 69 is provided with a liquid pressure gauge 34 for detecting the pressure of supercritical pressure liquefied carbon dioxide Lp flowing inside and a liquid thermometer 35 as a temperature detector for detecting temperature.

  The liquefied carbon dioxide Ln produced by the carbon dioxide condenser 42 is typically a saturated liquid or supercooled liquid of carbon dioxide, but is a supercooled liquid from the viewpoint of preventing the occurrence of cavitation in the booster pump 28. Is preferred. As a configuration in which the liquefied carbon dioxide Ln is used as a supercooled liquid, the carbon dioxide condenser 42 may be configured to be able to further lower the temperature after condensing the dehumidified carbon dioxide gas Gdh into a saturated liquid, A subcooler (not shown) may be provided separately from the carbon dioxide condenser 42. As another cavitation prevention measure, the discharge flow rate of the booster pump 28 is configured such that the rotational speed of the impeller of the booster pump 28 can be adjusted, or a valve whose opening degree can be adjusted is provided on the discharge side of the booster pump 28. By adjusting, the height of the liquid level of the liquefied carbon dioxide Ln stored in the lower part of the carbon dioxide condenser 42 may be secured to a predetermined height or more. If the tube 42t is submerged in the liquefied carbon dioxide Ln, the submerged portion of the tube 42t can function as a subcooler.

  The control device 80 is a device that controls the operation of the carbon dioxide liquefying device 1. The control device 80 is connected to the liquid pressure gauge 34 and the condenser pressure gauge 64 via signal cables, respectively, and is configured to receive a pressure signal. The control device 80 is connected to the liquid thermometer 35 and the gas thermometer 65 through signal cables, respectively, and is configured to receive a temperature signal. The control device 80 is connected to the flow rate adjustment valve 33 and the flow rate adjustment valve 49 via signal cables, respectively, and is configured to be able to adjust the opening degree of each of the flow rate adjustment valves 33 and 49. Moreover, the control apparatus 80 can transmit a command signal to each of the 1st compressor 11P, the 2nd compressor 12P, and the 3rd compressor 13P, and controls on / off of 11P, 12P, and 13P of each compressor. It is configured to be able to. Moreover, the control apparatus 80 can transmit a command signal to the refrigerator 40, and is comprised so that the refrigerating capacity | capacitance (and temperature of the cold water C manufactured) of the refrigerator 40 can be controlled.

  The operation of the carbon dioxide liquefier 1 will be described with reference to FIGS. FIG. 2 is a ph (pressure-specific enthalpy) diagram of carbon dioxide showing the state of carbon dioxide in the mixed gas Gm. The state of carbon dioxide mentioned below (represented by the symbol “SX” with a serial number X (X is a natural number) after the letter S on the ph diagram) is a mixed gas Gm or dehumidified carbon dioxide gas Gdh or The state of carbon dioxide in the liquefied carbon dioxide Ln or the supercritical pressure liquefied carbon dioxide Lp is represented.

  When the mixed gas Gm in the state S1 is introduced into the pressure increasing dehydrator 10, first, the mixed gas Gm is cooled by the first cooler 11C to be in the state S2, and then the condensation generated with the cooling of the mixed gas Gm in the first cooler 11C. After the water is removed by the first gas-liquid separator 11S, the pressure is increased by the first compressor 11P to enter the state S3. Subsequently, it cools with the 2nd cooler 12C, and it will be in state S4, and after the condensed water accompanying cooling is removed by the 2nd gas-liquid separator 12S, it will be pressure | voltage-risen by 2nd compressor 12P and will be in state S5. Further, after being cooled by the third cooler 13C to become the state S6, the condensed water accompanying the cooling is removed by the third gas-liquid separator 13S, and then the pressure is increased to the first predetermined pressure P1 by the third compressor 13P. State S7. Here, the first predetermined pressure P1 is lower than the critical pressure of carbon dioxide (about 7.4 MPa (absolute pressure)), and the dehumidified carbon dioxide gas Gdh contains allowable moisture. However, from the viewpoint of avoiding freezing of moisture, a pressure higher than the pressure at which the saturation temperature of carbon dioxide is 0 ° C. is preferable, and typically a general-purpose refrigerator can be used as the refrigerator 40. The temperature of the cold water C introduced into the carbon dioxide condenser 42 (for example, about 7 to 13 ° C.) is a pressure equal to or higher than the pressure at which the carbon dioxide saturation temperature is reached. As described above, in the pressurizing and dehydrating apparatus 10, the mixed gas Gm in the state S1 is boosted to the state S7 that is the first predetermined pressure.

  The mixed gas Gm whose pressure has been increased to the state S7 by the pressure increasing dehydration apparatus 10 is introduced into the fourth cooler 21 and cooled, and the specific enthalpy is decreased and the temperature is decreased to the state S8. The state S8 depends on the state of the cooling fluid F that changes depending on the conditions of the place where the carbon dioxide liquefying apparatus 1 is installed and natural conditions such as seasonal changes. For example, when the cooling fluid F is cooled by a cooling tower, the temperature of the cooling water in Japan is about 32 ° C. in the city center and about 24 ° C. in the cold district. As in the present embodiment, when the temperature of the mixed gas Gm in the state S7 is 169 ° C., if the temperature of the cooling fluid F is 32 ° C. and the temperature efficiency of the fourth cooler 21 is 80%, The mixed gas Gm that is in the state S8 due to the cooling in the fourth cooler 21 is about 60 ° C. The mixed gas Gm cooled to the state S8 by the fourth cooler 21 is introduced into the cold heat recovery device 30 and is cooled by heat exchange with the supercritical pressure liquefied carbon dioxide Lp to be in the state S9. By providing the cold heat recovery device 30, it is possible to recover the cold heat held by the supercritical pressure liquefied carbon dioxide Lp, so that compared with the case of cooling from the state S8 to the state S9 using external energy. It becomes energy saving.

  The mixed gas Gm cooled to the state S9 by the cold heat recovery device 30 is introduced into the moisture condenser 41 and cooled by the cold water C to be in the state S10. At this time, the control device 80 receives the temperature of the mixed gas Gm after being cooled by the moisture condenser 41 detected by the gas thermometer 65 as a signal, and the temperature detected by the gas thermometer 65 is the predetermined value described above. The flow rate of the cold water C flowing into the water condenser 41 by adjusting the opening degree of the flow rate control valve 49 so that the temperature is higher than the condensation temperature of carbon dioxide at the pressure P1 and can extract condensed water as much as possible. To control. By setting the mixed gas Gm cooled by the moisture condenser 41 to a predetermined temperature higher than the condensation temperature of carbon dioxide, it can be avoided that the carbon dioxide in the mixed gas Gm is condensed and mixed with condensed water. As a result, it is possible to avoid that carbon dioxide is discharged out of the system together with the condensed water. In other words, by making the surface temperature of the finned tube of the moisture condenser 41 higher than the condensation temperature of carbon dioxide, that is, the dew point, it is possible to avoid the condensation of carbon dioxide and mixing with the condensed water. However, instead of directly detecting the tube surface temperature, the tube surface temperature is estimated and controlled by the temperature of the mixed gas Gm at the outlet of the water condenser 41.

  The mixed gas Gm cooled to the state S10 by the moisture condenser 41 is guided to the fourth gas-liquid separator 25, and after the condensed water generated by the moisture condenser 41 is removed, the mixed gas Gm is introduced into the dehumidifier 50 and mixed. The moisture in the gas Gm is removed until it reaches the above-mentioned predetermined concentration (concentration that does not hinder the flow when it is condensed to the liquefied carbon dioxide Ln later) to obtain the dehumidified carbon dioxide gas Gdh. The state of carbon dioxide in the dehumidified carbon dioxide gas Gdh is generally the state S10. Before the mixed gas Gm is introduced into the dehumidifier 50, the moisture in the mixed gas Gm is cooled and condensed by the moisture condenser 41 and removed by the fourth gas-liquid separator 25. Therefore, the moisture removed by the dehumidifier 50 Can be minimized, and the energy required to regenerate the adsorbent or absorbent of the dehumidifier 50 can be reduced.

  The dehumidified carbon dioxide gas Gdh is then introduced into the carbon dioxide condenser 42 and cooled by the cold water C to become the liquefied carbon dioxide Ln in the state S11. Here, it is assumed that the state S11 is a liquid supercooled by about 1 ° C. from the state of the saturated liquid carbon dioxide at the pressure P1. The supercooling of 1 ° C. is a supercooling of about 145 kPa high pressure with respect to the saturation pressure of the carbon dioxide condenser 42, and is about 16.5 m when converted to an effective NPSH for the booster pump 28. The liquefied carbon dioxide Ln is once stored in the lower part of the shell 42 b and then flows into the booster pump 28 due to gravity and suction of the booster pump 28. The liquefied carbon dioxide Ln flowing into the booster pump 28 is boosted to the second predetermined pressure P2 by the booster pump 28 and becomes the supercritical pressure liquefied carbon dioxide Lp in the state S12. Here, the second predetermined pressure P2 is, for example, a pressure necessary for embedding the supercritical pressure liquefied carbon dioxide Lp in the ground or in the deep sea, that is, the supercritical pressure liquefied carbon dioxide Lp is processed. This is the pressure required. The supercritical pressure liquefied carbon dioxide Lp boosted to the state S12 by the booster pump 28 is pumped through the liquid pipe 68.

  The supercritical pressure liquefied carbon dioxide Lp flowing through the liquid pipe 68 flows into the cold heat recovery unit 30 and exchanges heat with the mixed gas Gm in the state S8 to increase the specific enthalpy and enter the state S13 (as described above, the mixed gas Gm goes from state S8 to state S9.) Thus, in the carbon dioxide liquefying apparatus 1, the cold heat held by the supercritical pressure liquefied carbon dioxide Lp can be collected in the cold heat recovery device 30, and energy saving can be achieved. Conventionally, for example, in liquefied natural gas, steam is generated when the temperature of the liquid is increased after the natural gas is liquefied. Therefore, it has not been considered to collect cold heat from the liquid in the liquefaction apparatus. On the other hand, in the carbon dioxide liquefying apparatus 1, in consideration of later transport, carbon dioxide is supercritical pressure liquefied carbon dioxide Lp which is a supercritical fluid exceeding the critical pressure. Even if the temperature of Lp rises to some extent (several degrees to several tens of degrees Celsius), a two-phase flow due to the generation of steam does not occur, and there is no concern about so-called vapor lock. Can be recovered. Moreover, when storing carbon dioxide in the ground or deep sea bottom, the supercritical pressure liquefied carbon dioxide Lp being pumped eventually becomes the ambient temperature of the ground or seawater, in other words, the cold energy is lost. . Therefore, by recovering the cold before being pumped to the ground or the deep sea floor, the energy of the cold lost due to the ambient temperature can be reduced.

  At this time, the specific volume of the supercritical pressure liquefied carbon dioxide Lp also increases with an increase in specific enthalpy (temperature increase) due to heat exchange with the mixed gas Gm. When the specific volume is increased, the flow rate when the supercritical pressure liquefied carbon dioxide Lp flows through the outlet liquid pipe 69 and the conduit (not shown) to the previous use point increases, and the pressure loss also increases. In order to suppress the increase in the specific volume of the supercritical pressure liquefied carbon dioxide Lp, the control device 80 receives the temperature of the supercritical pressure liquefied carbon dioxide Lp detected by the liquid thermometer 35 as a signal, and the liquid thermometer 35 The supercritical flow that flows into the cold heat recovery unit 30 by adjusting the opening degree of the flow rate control valve 33 so that the temperature to be detected is equal to or lower than the temperature that becomes the specific volume allowed by the pressure detected by the liquid pressure gauge 34. The flow rate of the pressure liquefied carbon dioxide Lp is controlled. By setting the temperature of the supercritical pressure liquefied carbon dioxide Lp flowing through the outlet liquid pipe 69 to be equal to or lower than the temperature that allows the specific volume, an increase in pressure loss when flowing in the pipe can be suppressed, and energy saving can be achieved. Can do.

  As described above, in the carbon dioxide liquefying apparatus 1 according to the present embodiment, the carbon dioxide gas is condensed at the first predetermined pressure and then increased to the second predetermined pressure in a liquid state. Therefore, carbon dioxide can be used as a supercritical fluid with less energy than in the case where the pressure is increased to the second predetermined pressure in a gas state. For example, without using the refrigerator 40 and the booster pump 28 for the moisture condenser 41 and the carbon dioxide condenser 42, the power required when the pressure is increased from the state S8 to the pressure P2 by the compressor, The power for generating the supercritical pressure liquefied carbon dioxide Lp by the carbon dioxide liquefying apparatus 1 according to the present embodiment is only 93%. Further, since the cold heat recovery device 30 is provided to recover the cold heat of the supercritical pressure liquefied carbon dioxide Lp and use it for cooling the mixed gas Gm, energy is saved correspondingly, and 91% of the cold heat is not recovered. It only takes power. Furthermore, since the moisture in the mixed gas Gm introduced into the dehumidifier 50 is removed as much as possible by providing the moisture condenser 41 and the fourth gas-liquid separator 25, the load on the dehumidifier 50 can be reduced, Less energy is required for regeneration, saving energy. In order to further save energy, the dehumidifier 50 may be configured as follows.

  FIG. 3 is a partial system diagram showing a schematic configuration around the dehumidifier of the carbon dioxide liquefying apparatus according to the modification of the embodiment of the present invention, and (a) is a carbon dioxide liquefying apparatus 1A according to the first modification. (B) is a partial systematic diagram of the carbon dioxide liquefier 1B concerning the 2nd modification. The configurations of the carbon dioxide liquefier 1A and the carbon dioxide liquefier 1B other than those around the dehumidifier are the same as those of the carbon dioxide liquefier 1 (see FIG. 1).

  A carbon dioxide liquefying apparatus 1A shown in FIG. 3A replaces the dehumidifier 50 (see FIG. 1) in the carbon dioxide liquefier 1 (see FIG. 1), and is a solid adsorbent as a moisture deprivation medium that adsorbs moisture. And a second dehumidifying / reproducing device 51B having the same configuration as the first dehumidifying / reproducing device 51A. The gas pipe 61 is connected to the first dehumidifying regenerator 51A. One end of the branch gas introduction pipe 73 is connected to the gas pipe 61 between the fourth gas-liquid separator 25 and the first dehumidification regenerator 51A, and the other end of the branch gas introduction pipe 73 is the second dehumidification regenerator. 51B. One end of a branch gas outlet pipe 74 is connected to the second dehumidifying regenerator 51B opposite to the side to which the branch gas inlet pipe 73 is connected, and the other end of the branch gas outlet pipe 74 is connected to the first dehumidifying regeneration. The gas pipe 61 between the vessel 51A and the carbon dioxide condenser 42 is connected. A three-way valve 83 for switching between introducing the mixed gas Gm into the first dehumidifying regenerator 51A and introducing the mixed gas Gm into the second dehumidifying regenerator 51B is disposed at the connecting portion between the gas pipe 61 and the branch gas introducing pipe 73. Has been. At the connecting portion between the gas pipe 61 and the branch gas outlet pipe 74, it is assumed that the dehumidified carbon dioxide gas Gdh introduced into the carbon dioxide condenser 42 is derived from the first dehumidifying regenerator 51A or the second dehumidifying regeneration. A three-way valve 84 is provided for switching whether to derive from the vessel 51B.

  One end of a regeneration gas pipe 71 for extracting the dehumidified carbon dioxide gas Gdh as the regeneration gas Gr is connected to the gas pipe 61 on the carbon dioxide condenser 42 side from the position where the three-way valve 84 is provided. After the other end of the regeneration gas pipe 71 is branched into a first regeneration gas pipe 71A and a second regeneration gas pipe 71B, the first regeneration gas pipe 71A is supplied to the first dehumidifying regenerator 51A for the second regeneration. The gas pipe 71B is connected to the second dehumidifying regenerator 51B. At the branch portion between the first regeneration gas pipe 71A and the second regeneration gas pipe 71B, switching between introducing the regeneration gas Gr into the first dehumidifying regenerator 51A and introducing it into the second dehumidifying regenerator 51B is performed. A three-way valve 81 is provided. In the regeneration gas pipe 71, a heat exchanger 52 for preheating the regeneration gas Gr and a heater 53 for heating the regeneration gas Gr are arranged in this order along the flow direction of the regeneration gas Gr. The heater 53 typically introduces a discharge gas H (typically a gas from which a part of the mixed gas Gm has been extracted) discharged from the compressors 11P, 12P, 13P of the pressurization dehydration apparatus 10. It is configured as follows. The discharge gas H has a high temperature due to the heat generated with the compression work of the compressors 11P, 12P, and 13P. The regeneration gas Gr is heated by the energy of the high temperature discharge gas H. However, if there is other high temperature exhaust heat, it may be used to save energy.

  Further, a first post-regeneration gas pipe 72A is connected to the first dehumidification regenerator 51A, and a second post-regeneration gas pipe 72B is connected to the second dehumidification regenerator 51B. The first post-regeneration gas pipe 72A and the second post-regeneration gas pipe 72B are connected to the post-regeneration gas pipe 72, respectively. A connection between the first post-regeneration gas pipe 72A and the second post-regeneration gas pipe 72B and the post-regeneration gas pipe 72 allows the post-regeneration gas pipe 72 to communicate with the first post-regeneration gas pipe 72A and the second regeneration. A three-way valve 82 for switching between communication with the rear gas pipe 72B is provided. The post-regeneration gas pipe 72 after the three-way valve 82 is connected to the gas pipe 61 between the second compressor 12P and the third cooler 13C of the pressurization dehydration apparatus 10 after passing through the heat exchanger 52. Each of the three-way valves 81, 82, 83, 84 is configured such that the fluid flow is switched by a signal from the control device 80.

  In the carbon dioxide liquefying apparatus 1A configured as described above, the two three-way valves 83 and 84 are initially controlled in the direction in which the mixed gas Gm is introduced and led out from the first dehumidifying regenerator 51A, while the other 2 The three three-way valves 81 and 82 are controlled so that the regeneration gas Gr is introduced into the second dehumidifying regenerator 51B, and the moisture-containing gas Gk including water vapor exiting from the adsorbent is derived. When the carbon dioxide liquefier 1A is operated in this state, the mixed gas Gm from which the moisture has been removed by the fourth gas-liquid separator 25 is introduced into the first dehumidifying regenerator 51A, and the moisture in the mixed gas Gm is changed to the first. The first dehumidifying regenerator 51A is adsorbed by the adsorbent filled into the dehumidifying carbon dioxide gas Gdh, and is derived from the first dehumidifying regenerator 51A. Most of the dehumidified carbon dioxide gas Gdh derived from the first dehumidifying regenerator 51A is introduced into the carbon dioxide condenser 42, but a part thereof is introduced into the regeneration gas pipe 71 (to facilitate discrimination). This is referred to as “regenerative gas Gr”). The regeneration gas Gr flowing through the regeneration gas pipe 71 is first introduced into the heat exchanger 52, heat-exchanged with the moisture-containing gas Gk, and the temperature rises. Then, the heater 53 adsorbs the adsorbent by the discharge gas H. Heated to a temperature at which moisture can be evaporated. The regeneration gas Gr heated by the heater 53 is introduced into the second dehumidifying regenerator 51B in which the mixed gas Gm is not introduced.

  The regeneration gas Gr introduced into the second dehumidifying regenerator 51B evaporates the moisture adsorbed by the adsorbent with the heat it has. The regeneration gas Gr is derived from the second dehumidification regenerator 51B as a water-containing gas Gk mixed with the water vapor released from the adsorbent. After that, the moisture-containing gas Gk is introduced into the heat exchanger 52 to give heat to the regeneration gas Gr, and the temperature of the moisture-containing gas Gk itself decreases, flows through the gas pipe 72 after regeneration, and the second compressor 12P and the third cooler 13C. Is introduced into the gas pipe 61 between the two, and merges with the mixed gas Gm.

  If such an operation is continued, the adsorption capacity of the adsorbent of the first dehumidifying regenerator 51A decreases. Then, the control device 80 switches the three-way valves 81, 82, 83, 84 so that the mixed gas Gm is introduced into the second dehumidifying regenerator 51B, and the regenerating gas Gr is supplied to the first dehumidifying regenerator 51A. To be introduced. Thereby, the mixed gas Gm is dehumidified by the second dehumidifying regenerator 51B in which the adsorbent has been regenerated by the regenerating gas Gr and the adsorption capacity has been recovered, and the dehumidified carbon dioxide gas Gdh is generated, while the first dehumidifying regeneration is performed. In the vessel 51A, the adsorbent is regenerated by introducing the regeneration gas Gr. Thus, both the first dehumidifying regenerator 51A and the second dehumidifying regenerator 51B function as a moisture depriving unit that deprives moisture in the mixed gas Gm, and as a regenerating unit that heats the adsorbent and evaporates the moisture. In addition, it has a configuration in which the moisture capturing unit and the regenerating unit are switched over time. At the time of switching, heating of the regeneration gas Gr is stopped before switching, and the dehumidifying regenerators 51A and 51B are cooled with the regeneration gas Gr, so that the adsorption action after the switching can be continued smoothly.

  Next, a carbon dioxide liquefying apparatus 1B shown in FIG. 3B replaces the dehumidifier 50 (see FIG. 1) in the carbon dioxide liquefying apparatus 1 (see FIG. 1) with an absorbing liquid as a moisture deprivation medium that absorbs moisture. A dehumidifying part 55 is provided as a moisture depriving part from which moisture in the mixed gas Gm is absorbed and removed by Q (liquid absorbent). As the absorbing liquid Q, for example, ethylene glycol is used. One end of an absorption liquid introduction pipe 75 for introducing the absorption liquid Q is connected to the upper portion of the dehumidifying part 55, and one end of an absorption liquid outlet pipe 76 for deriving the absorption liquid Q after absorbing moisture is connected to the lower part. Yes. The other end of the absorption liquid outlet tube 76 is connected to a rectifier 58. Further, a heat exchanger 56 that preheats the absorbing liquid Q and a heater 57 that heats the absorbing liquid Q are arranged in this order along the flow direction of the absorbing liquid Q in the absorbing liquid outlet pipe 76. Typically, the heater 57 is supplied with the discharge gas H discharged from the compressors 11P, 12P, and 13P of the pressurization dehydration apparatus 10, and the absorption liquid Q is heated by the energy of the high-temperature discharge gas H. However, if there is other high-temperature exhaust heat, it may be used to save energy.

  The other end of the absorption liquid introduction pipe 75 is connected to the lower part of the rectifier 58. The absorbing liquid introduction pipe 75 is configured to pass through the heat exchanger 56 between the rectifier 58 and the dehumidifying unit 55. The heat exchanger 56 is a device that performs heat exchange between the concentrated absorbent Qs, which is the absorbent Q having a relatively high concentration, and the diluted absorbent Qw, which is the absorbent Q that has been reduced in concentration by absorbing moisture. . The upper part of the rectifier 58 communicates with the partial condenser 59A and the water condenser 59B through steam pipes 77A and 77B through which steam flows. The partial condenser 59 </ b> A is a device that condenses a part of the introduced water vapor and returns the condensed water to the rectifier 58 via the condensed water pipe 78. The water condenser 59B is a device that cools and condenses the introduced water vapor. The dehumidifying unit 55 is provided with a spray nozzle (not shown) for spraying the absorbing liquid Q. In addition, the dehumidifying unit 55 has a portion of the cold water transition pipe 45 disposed therein so that cold water C can be introduced to remove the heat of absorption generated when the absorbing liquid Q absorbs moisture. Has been.

  In the carbon dioxide liquefier 1B configured as described above, when the mixed gas Gm is introduced into the dehumidifying unit 55 via the gas pipe 61 and the concentrated absorbent Qs is introduced via the absorbent introduction pipe 75. The water in the mixed gas Gm is absorbed by the concentrated absorbent Qs, the mixed gas Gm becomes the dehumidified carbon dioxide gas Gdh, and the concentrated absorbent Qs becomes the diluted absorbent Qw. Absorption heat generated when the concentrated absorbent Qs absorbs moisture is removed by the cold water C. The dehumidified carbon dioxide gas Gdh flows through the gas pipe 61 toward the carbon dioxide condenser 42. On the other hand, the diluted absorbing liquid Qw flows through the absorbing liquid lead-out pipe 76, is first introduced into the heat exchanger 56, heat-exchanges with the concentrated absorbing liquid Qs, rises in temperature, and then heated by the discharge gas H in the heater 57, The water contained in the diluted absorbent Qw is introduced into the rectifier 58 in a state where the water is evaporated and separated (mixed flow of water vapor and concentrated absorbent Qs). In this way, the diluted absorbent Qw is heated by the heat exchanger 56 and the heater 57 to remove moisture, and is regenerated to the concentrated absorbent Qs that can absorb moisture again. Therefore, the heat exchanger 56 and the heater 57 are regenerated. Will constitute the part.

  In the mixed flow of water vapor and concentrated absorbent Qs introduced into the rectifier 58, the water vapor rises in the upper part and the concentrated absorbent Qs is stored in the lower part. The raised steam is introduced into the partial condenser 59A and the water condenser 59B through the steam pipes 77A and 77B. The partial condenser 59A condenses a part of the introduced steam and returns to the rectifier 58, The remainder of the water vapor introduced through the condenser 59A through the water condenser 59B is cooled and condensed here and then discharged out of the carbon dioxide liquefier 1B. On the other hand, after the concentrated absorbent Qs stored in the lower part of the rectifier 58 is introduced into the heat exchanger 56 through the absorbent introduction pipe 75 and heats the diluted absorbent Qw, the temperature itself decreases. Then, it flows through the absorption liquid introduction pipe 75 and is again introduced into the dehumidifying unit 55. The cooler 59A may be cooled with cooling water or with the diluted absorbent Qw before being introduced into the heat exchanger 56. The water condenser 59B is typically cooled with cooling water.

  In the above description, the pressurizing and dehydrating apparatus 10 is configured to perform three-stage boosting. However, depending on the state of the mixed gas Gm, the set value of the first predetermined pressure P1, etc., two-stage boosting or four-stage or more multistage boosting is performed. For example, the number of steps may be appropriately increased or decreased. For example, it suffices to have at least one of the first pressurization dehydration unit 11 to the third pressurization dehydration unit 13 (for example, the first pressurization dehydration unit 11) depending on the pressure of the inflowing mixed gas Gm. Further, depending on the temperature of the inflowing mixed gas Gm, the first boost dewatering unit 11 may be omitted. Further, the first gas-liquid separator 11S may be omitted depending on the water vapor content of the mixed gas Gm that flows in. That is, the pressurization dehydration apparatus 10 can determine the number of stages of the pressurization dehydration unit so that the state of the mixed gas Gm at the outlet can be set to a desired state. The gas-liquid separator can be omitted as appropriate.

  In the above description, it is assumed that the fourth cooler 21, the cold heat recovery unit 30, and the water condenser 41 of the configuration (gas-liquid heat exchanger) that exchanges heat between gas and liquid are fin tube heat exchangers. A gas-liquid heat exchanger having other configurations may be used.

  In the above description, the cold water C produced by the refrigerator 40 is supplied to the moisture condenser 41 and the carbon dioxide condenser 42. However, the refrigerant from the brine or the refrigerator may be supplied, or liquefied natural You may comprise so that gas may be supplied and this cold energy may be utilized. However, if the cold water C manufactured by the refrigerator 40 is supplied, a general-purpose refrigerator can be used, which is advantageous in terms of maintenance and initial cost. Further, the cold water C, which is the same cold medium, is supplied to the water condenser 41 and the carbon dioxide condenser 42, but the cold medium from different cold sources may be supplied to each of them.

  In the above description, the introduction cold heat amount adjusting means is constituted by the cold water bypass pipe 48 and the flow rate adjusting valve 49. For example, the system of the cold water C introduced into the water condenser 41 is the carbon dioxide condenser 42. In the case where it is different from the system of the cold water C introduced into the water condenser 41, it may be constituted by a flow rate adjusting valve or an inverter pump that makes the discharge flow rate of the pump that pumps the cold water C introduced into the moisture condenser 41 variable. Or you may comprise the refrigerator which manufactures the cold water C introduce | transduced into the water | moisture content condenser 41 with the cold water temperature setting apparatus (for example, control apparatus etc. which perform capacity control) which makes the temperature of the cold water C variable. When the mixed gas Gm is cooled by the refrigerant from the refrigerator 40, the refrigerant is supplied in parallel to the moisture condenser 41 and the carbon dioxide condenser 42, and the flow rate control valve 49 directly controls the refrigerant supply amount. It may be configured.

  In the above description, the exchange heat amount adjusting means is constituted by the liquid bypass pipe 32 and the flow rate adjusting valve 33, but the bypass for bypassing the cold heat recovery device 30 toward the mixed gas Gm flow path (gas pipe 61). The flow rate of the mixed gas Gm introduced into the cold heat recovery unit 30 may be changed by providing a pipe and a flow rate adjusting valve in the bypass pipe, or the refrigerator that produces the cold water C is cold water. Supercritical pressure liquefied carbon dioxide introduced into the cold heat recovery unit 30 by adjusting the temperature of the liquefied carbon dioxide Ln with a chilled water temperature setting device (for example, a control device that performs capacity control) that makes the temperature of C variable. It is good also as adjusting the holding | maintenance amount of cold heat of Lp.

  In the above description, the liquefied carbon dioxide Ln is the supercritical pressure liquefied carbon dioxide Lp that has been boosted to exceed the critical pressure of carbon dioxide. It is not necessary to provide 30.

DESCRIPTION OF SYMBOLS 1, 1A, 1B Carbon dioxide liquefaction device 10 Pressure dehydration device 21 Fourth cooler 28 Booster pump 30 Cold heat recovery device 41 Water condenser 42 Carbon dioxide condenser 45 Cold water crossover pipe 46 Cold water return pipe 48 Cold water bypass pipe 49 Flow control valve 50 Dehumidifier 51A First Dehumidifier / Regenerator 51B Second Dehumidifier / Regenerator 52 Heat Exchanger 53 Heater 55 Dehumidifier 56 Heat Exchanger 57 Heater 65 Gas Thermometer 80 Controller C Cold Water F Cooling Medium Gm Mixed Gas Gdh Dehumidified Carbon Dioxide Gas Ln Liquefied carbon dioxide Lp Supercritical pressure liquefied carbon dioxide Q Absorbing liquid

Claims (4)

Introducing a mixed gas containing carbon dioxide as a main component and containing water vapor, increasing the pressure of the mixed gas to a first predetermined pressure lower than the critical pressure of carbon dioxide, and removing part of moisture in the mixed gas With the device;
A cooler that cools the mixed gas derived from the pressurizing and dehydrating apparatus with a cooling medium that retains cold energy derived from air or water existing in a natural environment;
A water condenser that cools the mixed gas after passing through the cooler to a predetermined temperature higher than a condensation temperature of carbon dioxide at the first predetermined pressure to condense water in the mixed gas;
A dehumidifying device for removing moisture in the mixed gas after passing through the moisture condenser, wherein the dehumidifying device generates dehumidified carbon dioxide gas in which the moisture concentration in the mixed gas is reduced to a predetermined concentration;
A carbon dioxide condenser that cools and condenses the dehumidified carbon dioxide gas to produce liquefied carbon dioxide whose main component is a condensate of carbon dioxide;
Carbon dioxide liquefaction equipment. A cooling fluid flow path for introducing and deriving a cooling fluid for cooling the mixed gas to the moisture condenser;
Introduced cold heat amount adjusting means for adjusting a cold heat amount per unit time of the cooling fluid introduced into the moisture condenser;
A temperature detector for detecting the temperature of the mixed gas derived from the moisture condenser;
A control device that controls the introduction cold heat amount adjusting means so that the temperature detected by the temperature detector becomes the predetermined temperature;
The carbon dioxide liquefying apparatus according to claim 1. A pump that boosts the liquefied carbon dioxide to a second predetermined pressure that exceeds a critical pressure of carbon dioxide;
A heat exchanger for exchanging heat between the supercritical pressure liquefied carbon dioxide, which is the liquefied carbon dioxide boosted by the pump, and the mixed gas before being introduced into the moisture condenser;
The carbon dioxide liquefying apparatus according to claim 1 or 2. The dehumidifying device includes a moisture deprivation medium that deprives moisture of a moisture deprivation medium that deprives moisture in the mixed gas, and a regeneration unit that heats the moisture deprivation medium and evaporates the moisture from the moisture deprivation medium. The regeneration unit accepts the heat discharged from the pressurization dehydrator and heats the moisture deprivation medium;
The carbon dioxide liquefying apparatus according to any one of claims 1 to 3.