KR20100127359A - Carbon dioxide liquefaction equipment using internal heat exchange - Google Patents

Abstract

PURPOSE: A carbon dioxide of the bulk using the inside heat exchange for increasing the efficiency of the carbon dioxide liquefaction process is provided to perform carrying and discard of the carbon dioxide and increase high efficiency carbon dioxide liquefaction plant using the inside heat exchange. CONSTITUTION: A high efficiency carbon dioxide liquefaction plant(100) using inside heat exchange includes a heat exchanger(110) for respective inflow and the exhausted carbon dioxide. The carbon dioxide heat exchanger passes through the atmospheric carbon dioxide of the low pressure low temperature. A carbon dioxide compressor(120) compresses the atmospheric carbon dioxide of the pressure high temperature. The liquid carbon dioxide of the pressure super low temperature passes through the liquefier of carbon dioxide.

Description

Carbon Dioxide Liquefaction Equipment Using Internal Heat Exchange

The present invention relates to a high efficiency carbon dioxide liquefaction apparatus using internal heat exchange.

Greenhouse gases are gases that absorb and radiate solar radiation with a specific wavelength in the range of thermal infrared radiation emitted by the Earth's surface, the atmosphere, and clouds to space. The greenhouse effect occurs due to the characteristics of these greenhouse gases, and mainly water vapor, carbon dioxide, nitrous oxide, methane, ozone, CFCs, etc. are the greenhouse gas components of the general global atmosphere that cause the greenhouse effect. Among these components, water vapor is produced primarily by the natural greenhouse effect, which is essential for maintaining global temperature.

Meanwhile, many industrial equipment currently use fossil fuels such as petroleum, natural gas, and coal as energy sources, and a large amount of carbon dioxide is emitted in the process of converting fossil fuel energy into other forms of energy. However, global warming problems have arisen due to artificially generated greenhouse gases such as carbon dioxide resulting from excessive use of fossil fuels caused by industrialization. According to the IPCC's 2007 report on climate change, 'global greenhouse gas emissions from human activities have been increasing since industrialization, and have increased 70% between 1970 and 2004.' One of the most important components of greenhouse gases is carbon dioxide, with anthropogenic emissions of carbon dioxide increasing by 80% between 1970 and 2004.

Conventionally, there have been various processes for collecting carbon dioxide generated in industrial sites, but as the risks such as the above-mentioned global warming problems are increasing, there is a need to collect and dispose of large amounts of carbon dioxide. Conventional carbon dioxide collection process was mostly a process that collects carbon dioxide at atmospheric pressure, it is not suitable for use in collecting a large amount of carbon dioxide.

A typical example of the process of collecting carbon dioxide is a process using an amine as a carbon dioxide absorbent. Figure 1 (A) is a simplified illustration of such a conventional carbon dioxide collection process system, in which atmospheric gas phase carbon dioxide is produced. However, atmospheric carbon dioxide has a low density, so when a large amount of carbon dioxide is generated, it is not easy to collect or transport it. Conventionally, since the carbon dioxide is collected for the purpose of reusing carbon dioxide, not for the purpose of collecting and disposing of carbon dioxide, the design conditions include that the amount of carbon dioxide obtained through the process is not large. There was no problem even if it was collected.

In addition, it was not necessary to consider the economics of the liquefaction process because of the small amount of carbon dioxide to be collected for reuse. That is, liquefied carbon dioxide was obtained by, for example, conventionally compressing carbon dioxide at room temperature and atmospheric pressure to a high pressure and then lowering the temperature. Figure 1 (B) is a simplified illustration of a conventional carbon dioxide liquefaction process system, conventionally used a process of liquefying carbon dioxide using a heat exchanger for the compressor and cooling.

However, as described above, due to factors such as the severity of the current global warming problem, the need and demand for an efficient process of collecting, transporting and discarding a large amount of carbon dioxide generated in industrial sites, etc. are gradually increasing. That is, carbon dioxide at low pressure is low in density and thus insufficient for the purpose of removing a large amount of greenhouse gases. Therefore, when carbon dioxide is liquefied to increase the density, storage, transportation, and disposal of a large amount of carbon dioxide is economical.

However, in the conventional carbon dioxide liquefaction process as shown in FIG. 1 (B), the carbon dioxide compressor not only consumes a large amount of power, but also requires an external cooling fluid to liquefy carbon dioxide. Therefore, there have been many problems in using the conventional carbon dioxide liquefaction process to treat a large amount of carbon dioxide.

Accordingly, the present invention has been made to solve the problems of the prior art as described above, an object of the present invention is to provide a high-efficiency carbon dioxide liquefaction apparatus using the internal heat exchange, to increase the efficiency of the carbon dioxide liquefaction process through the internal heat exchange. .

The high-efficiency carbon dioxide liquefaction apparatus using the internal heat exchange of the present invention for achieving the above object, in the carbon dioxide liquefaction apparatus 100 for liquefying gaseous carbon dioxide at low pressure room temperature into liquid carbon dioxide at a high pressure low temperature, gaseous carbon dioxide at low pressure room temperature And carbon dioxide heat exchange in which the low pressure ambient temperature gaseous carbon dioxide and the high pressure ultra low temperature liquid carbon dioxide are adjacent to each other but are introduced into and separated from each other so as to cool the gaseous carbon dioxide at low pressure and room temperature to the low pressure and low temperature by heat-exchanging the high pressure cryogenic liquid carbon dioxide to each other. Group 110; A carbon dioxide compressor (120) for compressing the low pressure low temperature gaseous carbon dioxide passed through the carbon dioxide heat exchanger (110) into the medium pressure high temperature gaseous carbon dioxide; The medium pressure high temperature gaseous carbon dioxide and the cooling fluid are adjacent to each other so as to liquefy the medium pressure high temperature gaseous carbon dioxide and the cooling fluid which have passed through the carbon dioxide compressor 120 to the medium pressure ultra low temperature liquid carbon dioxide. Carbon dioxide liquefier 130 is introduced and discharged into the isolated space, respectively; A carbon dioxide pressurizing pump 150 for pressurizing the medium pressure cryogenic liquid carbon dioxide released through the carbon dioxide liquefier 130 into the high pressure cryogenic liquid carbon dioxide; It is made, including, the high pressure cryogenic liquid carbon dioxide from the high pressure cryogenic pump 150 passed through the carbon dioxide heat exchanger (110) while passing through the carbon dioxide heat exchanger (110), the low pressure room temperature gaseous carbon dioxide introduced into the initial pressure by the low pressure liquid carbon dioxide of low temperature Characterized in that it is discharged as. At this time, the carbon dioxide liquefaction apparatus 100 is provided on the carbon dioxide flow path between the carbon dioxide liquefier 130 and the carbon dioxide pressure pump 150, the medium pressure cryogenic liquid phase passed through the carbon dioxide liquefier 130 A carbon dioxide gas-liquid separator 140 for separating gaseous carbon dioxide remaining in carbon dioxide from liquid carbon dioxide and introducing only liquid carbon dioxide into the carbon dioxide pressurizing pump 150; It is preferred to further comprise a.

In addition, the carbon dioxide liquefaction apparatus 100 is provided on the carbon dioxide flow path between the carbon dioxide compressor 120 and the carbon dioxide liquefier 130, the medium-pressure high temperature gaseous carbon dioxide and high pressure passed through the carbon dioxide compressor 120. The carbon dioxide-refrigerant heat exchanger 210 in which medium-pressure high-temperature gaseous carbon dioxide and high-pressure low-temperature liquid phase refrigerant flows into and out of the adjacent space, respectively, so as to cool the medium pressure high temperature gaseous carbon dioxide by exchanging the low temperature liquid refrigerants with each other. ), A refrigerant turbine 220 for compressing the high pressure and high temperature gaseous refrigerant passed through the carbon dioxide-refrigerant heat exchanger 210 into a low pressure and low temperature gaseous refrigerant, and the carbon dioxide pressure pump 150 and the carbon dioxide heat exchanger ( It is provided on the carbon dioxide flow path between the 110, and passed through the carbon dioxide pressure pump 150 The high pressure ultra low temperature liquid carbon dioxide and the low pressure low temperature low temperature low temperature low temperature low temperature liquid phase refrigerant to condense the low pressure low temperature low temperature low temperature liquid phase refrigerant by heat-exchanging the low temperature low temperature low temperature low temperature low temperature low temperature low temperature low temperature low temperature low temperature low temperature low temperature liquid phase carbon dioxide A refrigerant pressure pump for pressurizing the low pressure low temperature liquid refrigerant passing through the refrigerant condenser 230 and the low pressure low temperature liquid refrigerant passing through the refrigerant condenser 230 with the gaseous refrigerants adjacent to each other but in an isolated space, respectively. Refrigerant power generation cycle (200) is made, including a high-temperature, low-temperature liquid refrigerant flowing through the refrigerant pressure pump 250 flows into the carbon dioxide- refrigerant heat exchanger 210, the cooling cycle is made; And further comprising: At this time, the refrigerant power generation cycle 200 is provided on the refrigerant passage between the refrigerant condenser 230 and the refrigerant pressure pump 250, the low pressure low temperature liquid refrigerant passing through the refrigerant condenser 230 The gas phase separator 240 may further include a refrigerant gas-liquid separator 240 that separates the remaining gaseous refrigerant from the liquid refrigerant to introduce only the liquid refrigerant into the refrigerant pressure pump 250.

In this case, the carbon dioxide liquefaction apparatus 100 includes the carbon dioxide liquefier 130 and the carbon dioxide-refrigerant heat exchanger 210 integrally as the first plate heat exchanger 310, and thus, the first plate heat exchanger ( A portion 310A of 310 may serve as the carbon dioxide liquefier 130, and the other portion 310B may serve as the carbon dioxide-refrigerant heat exchanger 210. In addition, the carbon dioxide liquefaction apparatus 100 comprises the carbon dioxide heat exchanger 110 and the refrigerant condenser 230 integrally as the second plate heat exchanger 320, a part of the second plate heat exchanger 320 ( 320A may serve as the carbon dioxide heat exchanger 110, and the remaining portion 320B may serve as the refrigerant condenser 230.

In addition, the cooling fluid is characterized in that the LNG.

According to the present invention, it is possible to solve the problem that it is difficult to treat a large amount of carbon dioxide generated in a large amount of industrial sites and the like, thereby liquefying a large amount of carbon dioxide much more economically and efficiently than conventional. More specifically, according to the present invention, since the efficiency of the carbon dioxide liquefaction process is increased through internal heat exchange, the energy consumption of the entire process is greatly reduced.

In addition, according to the present invention, since a large amount of carbon dioxide can be easily liquefied economically and efficiently, there is an effect that the transportation and disposal of carbon dioxide can be easily performed. Accordingly, it is possible to prevent the carbon dioxide generated at the industrial site from being thrown into the atmosphere, and as a result, there is also an environmentally friendly effect that can significantly reduce the greenhouse gas emissions.

Hereinafter, with reference to the accompanying drawings a high-efficiency carbon dioxide liquefaction apparatus using the internal heat exchange according to the present invention having the configuration as described above will be described in detail.

First, the cooling system will be briefly described. A heat exchanger is a device that absorbs heat from one side and dissipates heat to the other between two environments having a temperature difference. A heat exchange system including a heat exchanger is a cooling system that absorbs heat from a room and releases it to the outside. When heat is absorbed and released into the room, it acts as a heating system. Basically, the heat exchanger is composed of an evaporator that absorbs heat from the surroundings, a compressor compressing the heat exchange medium, a condenser that releases heat to the surroundings, and a turbine (or expansion valve) that expands the heat exchange medium. In the cooling system, the actual cooling action is caused by the evaporator in which the liquid refrigerant absorbs the amount of heat as vaporized heat from the surroundings and vaporizes. The gaseous refrigerant flowing from the evaporator into the compressor is compressed at a high temperature and high pressure in the compressor, and liquefied heat is released to the surroundings in the process of liquefying the compressed gaseous refrigerant through the condenser, and the liquefied refrigerant is again By passing through the turbine (or expansion valve) is a low-temperature and low-pressure wetted vapor state and then flows back into the evaporator to vaporize to form a cycle.

At this time, as described above, in the condenser, a refrigerant having a high temperature and high pressure gas flows in and condenses into a liquid state while releasing liquefied heat by heat exchange. The refrigerant in the gas phase and the liquid refrigerant are mixed. However, when the gaseous refrigerant and the liquid phase refrigerant are mixed, only equilibrium conditions can be obtained in temperature and pressure. Therefore, in order to increase the condenser efficiency, it is desirable to separate the liquid phase refrigerant that has already been condensed and the gaseous phase refrigerant that has not yet condensed. Do.

The basic forms of heat exchangers (ie evaporators and condensers) used in such cooling systems are well known, for example tube-fin heat exchangers consisting of header tanks, tubes and fins, or plate heat exchangers in which a plurality of plates are stacked. Heat exchangers of the type are known, and of course compressors, turbines, expansion valves and the like are also known in various forms. In addition, the operating principle of such a heat exchanger, a compressor, a turbine, an expansion valve is also well known. The present invention is a technology related to the heat exchange system itself, the following detailed description of the detailed form and operation principle of each part, such as heat exchanger, compressor, turbine, expansion valve, and the like will be omitted.

Figure 2 shows a carbon dioxide liquefaction apparatus of the present invention. As shown, the carbon dioxide liquefaction apparatus 100 of the present invention for liquefying gaseous carbon dioxide at low pressure and room temperature into liquid carbon dioxide at high pressure and low temperature includes a carbon dioxide heat exchanger 110, a carbon dioxide compressor 120, a carbon dioxide liquefier 130, and carbon dioxide. It consists of a pressure pump 150. The carbon dioxide liquefaction apparatus of the present invention uses some of the principles of the general cooling system as described above, but unlike the general cooling system in a simple cycle of sequentially passing through an evaporator-compressor-condenser-turbine, the carbon dioxide heat exchanger ( To pass the low pressure room temperature gaseous carbon dioxide (without the liquefaction process) as well as the high pressure ultra low temperature liquid carbon dioxide (near the last stage of the liquefaction process), thereby exchanging the low pressure room temperature gaseous carbon dioxide and the high pressure cryogenic liquid carbon dioxide with each other. This increases the heat exchange efficiency. Hereinafter, each part will be described in more detail.

The carbon dioxide heat exchanger 110 cools gaseous carbon dioxide at low pressure and room temperature to low pressure and low temperature by exchanging gaseous carbon dioxide at low pressure and room temperature and liquid carbon dioxide at high pressure and ultra low temperature. Therefore, the carbon dioxide heat exchanger 110, as shown in Figure 2 is to pass both the gaseous carbon dioxide of low pressure room temperature and the liquid carbon dioxide of high pressure ultra low temperature. Of course, the carbon dioxide in the two states should not be mixed with each other, the carbon dioxide heat exchanger 110 is formed so that the gaseous carbon dioxide at low pressure and room temperature and the liquid carbon dioxide at high pressure and ultra low temperature are adjacent to each other but introduced and discharged into an isolated space, respectively. As described above, technologies related to the form of heat exchangers for exchanging heat exchange media by allowing different types of heat exchange media to be adjacent to each other but enter and discharge into an isolated space are widely known, and thus, the detailed form of the carbon dioxide heat exchanger 110 itself is known. Description of the description is omitted.

The carbon dioxide compressor 120 compresses gaseous carbon dioxide having low pressure and low temperature obtained through the carbon dioxide heat exchanger 110 into gaseous carbon dioxide having a medium pressure and high temperature.

The carbon dioxide liquefier 130 heats the medium pressure high temperature gaseous carbon dioxide and the cooling fluid which have passed through the carbon dioxide compressor 120 to liquefy the medium pressure high temperature gaseous carbon dioxide into the medium pressure ultra low temperature liquid carbon dioxide. Therefore, the carbon dioxide liquefier 130, similar to the carbon dioxide heat exchanger 110, as shown in Figure 2 is to pass both the low pressure atmospheric gas phase carbon dioxide and the high pressure cryogenic liquid carbon dioxide. Also similar to the carbon dioxide heat exchanger 110, since the carbon dioxide in these two states should not be mixed with each other, the carbon dioxide liquefier 130 is a medium pressure high temperature gaseous carbon dioxide and cooling fluid are introduced into the adjacent space, but adjacent to each other And to be discharged. The cooling fluid may be any material as long as it is a low temperature fluid capable of cooling the medium pressure high temperature gaseous carbon dioxide.

In this case, the energy efficiency can be further increased by connecting to the LNG vaporization process in a facility that requires LNG vaporization, such as an LNG power plant. That is, when LNG is used as the cooling fluid, energy required for LNG vaporization can be reduced. FIG. 5 is a conventional LNG vaporization process, in which a vaporizer at the lower right of FIG. 5 vaporizes LNG. If the vaporizer is configured to act as a carbon dioxide liquefier, it is possible to perform liquefaction of carbon dioxide and vaporization of LNG at the same time with high efficiency.

The carbon dioxide pressurizing pump 150 pressurizes the medium pressure cryogenic liquid carbon dioxide that has passed through the carbon dioxide liquefier 130 to the high pressure cryogenic liquid carbon dioxide.

As described above, the high pressure cryogenic liquid carbon dioxide that has passed through the carbon dioxide pressure pump 150 is introduced into the carbon dioxide heat exchanger 110 as illustrated in FIG. 2. As the high pressure cryogenic liquid carbon dioxide passes through the carbon dioxide heat exchanger 110, it causes heat exchange with the gaseous carbon dioxide at low pressure and room temperature, which is initially introduced, and thus the high pressure cryogenic liquid carbon dioxide is finally discharged as high pressure and low temperature liquid carbon dioxide. . (Of course, in this process, the initially introduced low pressure atmospheric gaseous carbon dioxide is cooled by heat exchange with high pressure cryogenic liquid carbon dioxide to become low pressure low temperature gaseous carbon dioxide.)

At this time, the carbon dioxide liquefaction apparatus 100 of the present invention preferably further comprises a carbon dioxide gas liquid separator (140). As shown in FIG. 2, the carbon dioxide gas-liquid separator 140 is provided on a carbon dioxide flow path between the carbon dioxide liquefier 130 and the carbon dioxide pressurizing pump 150, and passes through the carbon dioxide liquefier 130. The gaseous carbon dioxide remaining in the liquid carbon dioxide in the medium pressure cryogenic temperature is separated from the liquid carbon dioxide, and only the liquid carbon dioxide is introduced into the carbon dioxide pressure pump 150.

In the conventional carbon dioxide liquefaction apparatus, as shown in FIG. 1 (B), only the low pressure room temperature gaseous carbon dioxide is passed through a carbon dioxide compressor and compressed (to become a high pressure high temperature gaseous carbon dioxide), which is cooled in a carbon dioxide liquefier. It was cooled and liquefied by heat exchange with and made into liquid carbon dioxide at high pressure and room temperature. On the other hand, in the present invention, it is possible to reduce the energy consumption of the carbon dioxide compressor by primarily cooling it by heat-exchanging with the high pressure ultra low temperature liquid carbon dioxide (nearly passed through the liquefaction apparatus) before introducing the gaseous carbon dioxide at low pressure and room temperature into the carbon dioxide compressor. give. In addition, by pressurizing the medium pressure cryogenic liquid carbon dioxide cooled and liquefied in the carbon dioxide liquefier once again, it also reduces energy consumption and attains high pressure cryogenic liquid carbon dioxide. That is, unlike the conventional high-pressure room temperature liquid carbon dioxide can be obtained, by using the carbon dioxide liquefaction apparatus of the present invention, it is possible to obtain a high-temperature, low-temperature liquid carbon dioxide while reducing energy consumption, thus the volume of carbon dioxide by much higher volume Will be reduced. In addition, the carbon dioxide liquefaction apparatus of the present invention does not require a separate energy to vaporize the high-pressure cryogenic carbon dioxide, and ultimately can greatly increase the overall efficiency of the system.

3 illustrates another embodiment of the carbon dioxide liquefaction apparatus of the present invention, in which a cooling power generation system is further provided in the apparatus of FIG. 2. The cooling power generation system 200 may further increase the liquefaction and cooling efficiency. The cooling power generation system 200 is a carbon dioxide-cooling heat exchanger 210 and a refrigerant turbine 220 as shown in FIG. 3. And a refrigerant condenser 230 and a refrigerant pressurizing pump 250, and a high-temperature, low-temperature liquid refrigerant passing through the refrigerant pressurizing pump 250 flows into the carbon dioxide-cooling heat exchanger 210, thereby providing a cooling cycle. This is done. Hereinafter, each part will be described in more detail.

The carbon dioxide-refrigerant heat exchanger 210 is provided on the carbon dioxide flow path between the carbon dioxide compressor 120 and the carbon dioxide liquefier 130, as shown in FIG. 3, and passes through the carbon dioxide compressor 120. The medium pressure high temperature gaseous carbon dioxide and the high pressure low temperature liquid phase refrigerant are heat-exchanged with each other, thereby cooling the medium pressure high temperature gaseous carbon dioxide. Thus, similar to the carbon dioxide heat exchanger 110 or the carbon dioxide liquefier 130, the carbon dioxide-refrigerant heat exchanger 210 is a medium pressure high temperature gaseous carbon dioxide and a high pressure low temperature liquid refrigerant adjacent to each other in an isolated space Respectively inlet and outlet.

The refrigerant turbine 220 compresses the high pressure and high temperature gaseous refrigerant passed through the carbon dioxide-refrigerant heat exchanger 210 into the low pressure and low temperature gaseous refrigerant. The refrigerant turbine 220 is to work through the expansion of the refrigerant, it is possible to supply a power source by connecting the refrigerant turbine 220 to the generator 260.

The refrigerant condenser 230 is provided on the carbon dioxide flow path between the carbon dioxide pressurizing pump 150 and the carbon dioxide heat exchanger 110, as shown in FIG. 3, and exits through the carbon dioxide pressurizing pump 150. By heat-exchanging the high-pressure ultra-low temperature liquid carbon dioxide and the low-pressure low-temperature gaseous refrigerant passing through the refrigerant turbine 220, the low-pressure low-temperature gaseous refrigerant is condensed into the low-pressure low-temperature liquid refrigerant. Therefore, the refrigerant condenser 230, also similar to the carbon dioxide heat exchanger 110 or the carbon dioxide liquefier 130, the high pressure ultra low temperature liquid carbon dioxide and the low pressure low temperature gaseous refrigerants are adjacent to each other but introduced into the isolated space, respectively And to be discharged.

The refrigerant pressurizing pump 250 pressurizes the low pressure low temperature liquid refrigerant that has passed through the refrigerant condenser 230 to the high pressure low temperature liquid refrigerant.

As described above, the refrigerant of the cooling power generation system 200 is vaporized or liquefied by heat exchange with carbon dioxide in some stages of the liquefaction process, and in this process, liquefaction of carbon dioxide is made more efficient. That is, by lowering the carbon dioxide gas temperature before the compressor through the internal heat exchange, it is possible to increase the density to reduce the compression energy consumption. In addition, the internal heat exchange can reduce the energy consumption required to increase the high-pressure carbon dioxide temperature. In addition, according to the present invention, by installing a closed-circuit refrigerant generation system to generate electricity or power energy, it is possible to maximize the overall efficiency of the system.

At this time, the carbon dioxide liquefaction apparatus 100 preferably further comprises a carbon dioxide gas liquid separator (140). As shown in FIG. 3, the carbon dioxide gas-liquid separator 140 is provided on a carbon dioxide flow path between the carbon dioxide liquefier 130 and the carbon dioxide pressurizing pump 150 and the carbon dioxide liquefier 130. The gaseous carbon dioxide remaining in the medium pressure cryogenic liquid carbon dioxide that has passed through is separated from the liquid carbon dioxide, and only the liquid carbon dioxide is introduced into the carbon dioxide pressure pump 150.

FIG. 4 shows another embodiment of the cooling power generation system of FIG. 3 as another embodiment of the carbon dioxide liquefaction apparatus of the present invention. As shown in FIG. 4, the carbon dioxide liquefier 130 and the carbon dioxide-refrigerant heat exchanger 210 may be integrally formed as the first plate heat exchanger 310. That is, a portion 310A of the first plate heat exchanger 310 serves as the carbon dioxide liquefier 130, and the remaining portion 310B serves as the carbon dioxide-cooling heat exchanger 210. Also, as shown in FIG. 4, the carbon dioxide heat exchanger 110 and the refrigerant condenser 230 are integrally formed as the second plate heat exchanger 320, thereby forming a part of the second plate heat exchanger 320 ( 320A may serve as the carbon dioxide heat exchanger 110, and the remaining portion 320B may serve as the refrigerant condenser 230.

The first and second plate heat exchangers 310 and 320 may use a plate heat exchanger having a plurality of inlets and outlets which are generally used in cryogenic gas liquefaction process, thereby simplifying the process. . That is, the carbon dioxide liquefaction, the refrigerant vaporization, and the cooling fluid temperature rise in the first plate heat exchanger 310, and the high pressure carbon dioxide temperature rise, the refrigerant condensation, and the low pressure carbon dioxide cooling occur simultaneously in the second plate heat exchanger 320.

The present invention is not limited to the above-described embodiments, and the scope of application of the present invention is not limited to those of ordinary skill in the art to which the present invention pertains without departing from the gist of the present invention as claimed in the claims. Of course, various modifications can be made.

1 is a system diagram of a conventional carbon dioxide collection and liquefaction process.

2 is a carbon dioxide liquefaction apparatus of the present invention.

3 is another embodiment of the carbon dioxide liquefaction apparatus of the present invention.

4 is another embodiment of the carbon dioxide liquefaction apparatus of the present invention.

5 illustrates an LNG vaporization process.

DESCRIPTION OF REFERENCE NUMERALS

100: carbon dioxide liquefaction apparatus 110: carbon dioxide heat exchanger

120: carbon dioxide compressor 130: carbon dioxide liquefier

140: carbon dioxide gas liquid separator 150: carbon dioxide pressure pump

200: refrigerant power generation cycle 210: carbon dioxide- refrigerant heat exchanger

220: refrigerant turbine 230: refrigerant condenser

240: refrigerant gas-liquid separator 250: refrigerant pressurized pump

Claims (7)

In the carbon dioxide liquefaction apparatus 100 for liquefying gaseous carbon dioxide at low pressure and room temperature into liquid carbon dioxide at high pressure and low temperature, By heat-exchanging the low pressure room temperature gaseous carbon dioxide and the high pressure ultra low temperature liquid carbon dioxide to each other, the low pressure room temperature gas phase carbon dioxide and the high pressure ultra low temperature liquid carbon dioxide are introduced into the adjacent spaces, respectively, to cool the low pressure low temperature and low temperature gas phase carbon dioxide. And carbon dioxide heat exchanger 110 discharged; A carbon dioxide compressor (120) for compressing the low pressure low temperature gaseous carbon dioxide passed through the carbon dioxide heat exchanger (110) into the medium pressure high temperature gaseous carbon dioxide; The medium pressure high temperature gaseous carbon dioxide and the cooling fluid are adjacent to each other so as to liquefy the medium pressure high temperature gaseous carbon dioxide and the cooling fluid which have passed through the carbon dioxide compressor 120 to the medium pressure ultra low temperature liquid carbon dioxide. Carbon dioxide liquefier 130 is introduced and discharged into the isolated space, respectively; A carbon dioxide pressurizing pump 150 for pressurizing the medium pressure cryogenic liquid carbon dioxide released through the carbon dioxide liquefier 130 into the high pressure cryogenic liquid carbon dioxide; And, The high pressure ultra low temperature liquid carbon dioxide which has passed through the carbon dioxide pressurizing pump 150 is discharged as high pressure low temperature liquid carbon dioxide by heat-exchanging with gaseous carbon dioxide of low pressure room temperature initially introduced while passing through the carbon dioxide heat exchanger 110. High efficiency carbon dioxide liquefaction apparatus using internal heat exchange. According to claim 1, wherein the carbon dioxide liquefaction apparatus 100 The gaseous carbon dioxide provided on the carbon dioxide flow path between the carbon dioxide liquefier 130 and the carbon dioxide pressure pump 150 and separated from the liquid carbon dioxide remaining in the medium pressure cryogenic liquid carbon dioxide passed through the carbon dioxide liquefier 130 is separated from the liquid carbon dioxide. A carbon dioxide gas-liquid separator 140 for introducing only liquid carbon dioxide into the carbon dioxide pressurizing pump 150; High efficiency carbon dioxide liquefaction apparatus using internal heat exchange, characterized in that further comprising. According to claim 1, wherein the carbon dioxide liquefaction apparatus 100 Medium pressure is provided on the carbon dioxide flow path between the carbon dioxide compressor 120 and the carbon dioxide liquefier 130, by heat-exchanging medium pressure high temperature gaseous carbon dioxide and high pressure low temperature liquid refrigerant passing through the carbon dioxide compressor 120, A carbon dioxide-refrigerant heat exchanger 210 into which medium-pressure high-temperature gaseous carbon dioxide and high-pressure low-temperature liquid phase refrigerant are introduced into and discharged into adjacent spaces, respectively, to cool the high-temperature gaseous carbon dioxide; Refrigerant turbine 220 for compressing the high-pressure high-temperature gaseous refrigerant passed through the carbon dioxide-refrigerant heat exchanger 210 to a low-pressure low-temperature gaseous refrigerant, It is provided on the carbon dioxide flow path between the carbon dioxide pressure pump 150 and the carbon dioxide heat exchanger 110, and passes through the high pressure ultra low temperature liquid carbon dioxide and the refrigerant turbine 220 that pass through the carbon dioxide pressure pump 150. The high pressure ultra low temperature liquid carbon dioxide and the low pressure low temperature gas phase refrigerant flow into and out of the adjacent space, respectively, so as to condense the low pressure low temperature gas phase refrigerants to each other, thereby condensing the low pressure low temperature gas phase refrigerants to the low pressure low temperature liquid phase refrigerant. Being a refrigerant condenser 230, A refrigerant pressure pump 250 for pressurizing the low pressure low temperature liquid refrigerant that has passed through the refrigerant condenser 230 to the high pressure low temperature liquid refrigerant And, A refrigerant power generation cycle 200 in which a high pressure low temperature liquid refrigerant, which has passed through the refrigerant pressurization pump 250, is introduced into the carbon dioxide-refrigerant heat exchanger 210 so that a cooling cycle is performed; High efficiency carbon dioxide liquefaction apparatus using internal heat exchange, characterized in that further comprising. The method of claim 3, wherein the refrigerant power generation cycle 200 It is provided on the refrigerant flow path between the refrigerant condenser 230 and the refrigerant pressure pump 250, the gaseous refrigerant remaining in the low pressure low temperature liquid refrigerant passed through the refrigerant condenser 230 is separated from the liquid refrigerant liquid Refrigerant gas-liquid separator 240 for introducing only refrigerant into the refrigerant pressure pump 250. High efficiency carbon dioxide liquefaction apparatus using internal heat exchange, characterized in that further comprising. The method of claim 3, wherein the carbon dioxide liquefaction apparatus 100 The carbon dioxide liquefier 130 and the carbon dioxide-refrigerant heat exchanger 210 are integrally formed as the first plate heat exchanger 310, so that a portion 310A of the first plate heat exchanger 310 is the carbon dioxide liquefier. 130, the high efficiency carbon dioxide liquefaction apparatus using internal heat exchange, characterized in that the remaining portion 310B is formed to serve as the carbon dioxide- refrigerant heat exchanger (210). The method of claim 3, wherein the carbon dioxide liquefaction apparatus 100 The carbon dioxide heat exchanger 110 and the refrigerant condenser 230 are integrally formed as the second plate heat exchanger 320, so that part 320A of the second plate heat exchanger 320 is the carbon dioxide heat exchanger 110. High efficiency carbon dioxide liquefaction apparatus using internal heat exchange, characterized in that the remaining portion (320B) is formed to serve as the refrigerant condenser (230). The method of claim 1, wherein the cooling fluid High efficiency carbon dioxide liquefaction apparatus using internal heat exchange, characterized in that the LNG.

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