JP2019035453A - Intermediate medium type carburetor - Google Patents

Abstract

To provide an intermediate medium type carburetor capable of preventing freezing of intermediate medium and improving efficiency of vaporization process for low-temperature liquefied gas, in a simple device configuration.SOLUTION: An intermediate medium type carburetor (1) is configured to transmit heat of heat source fluid (3) to low-temperature liquid gas through intermediate medium (2), to vapor the low-temperature liquid gas. The intermediate medium type carburetor (1) comprises an intermediate medium heating unit (E1) configured to heat liquid intermediate medium (2) by the heat of the heat source fluid (3), and a gas vaporization unit (E2) configured to vapor low-temperature liquid gas by the heat of the intermediate medium (2) heated at the intermediate medium heating unit (E1). The intermediate medium (2) contains antifreeze protein (4) having a freezing point higher than a temperature of the low-temperature liquid gas.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an intermediate medium vaporizer.

  Conventionally, as disclosed in Patent Document 1, as a device for vaporizing a low-temperature liquefied gas such as liquefied natural gas (LNG), heat of a heat source fluid such as seawater or air is liquefied through an intermediate medium. An intermediate-medium vaporizer is known that vaporizes a low-temperature liquefied gas by transmitting it to a gas.

  The vaporizer disclosed in Patent Document 1 includes an intermediate medium evaporation section that vaporizes a liquid intermediate medium by the heat of seawater that is a heat source fluid, and an LNG evaporation section that vaporizes LNG by the heat of the gaseous intermediate medium. I have. In this vaporizer, propane having a freezing point lower than the temperature of LNG (about −160 ° C.) is used as an intermediate medium. In Patent Document 2, as a means for preventing freezing of the liquid medium flowing in the heat exchanger, a fine particle removing unit that removes metal fine particles in the medium serving as a freezing nucleus with an electromagnet is provided on the upstream side of the heat exchanger. Is disclosed.

Japanese Patent Laid-Open No. 2014-219047 JP-A-5-332584

  In the vaporizer disclosed in Patent Document 1, in order to prevent the intermediate medium from freezing during heat exchange with LNG, the usable intermediate medium is a refrigerant such as propane having a freezing point lower than the temperature of LNG. Limited to In this case, the freezing of the intermediate medium by LNG can be prevented, but since propane is a medium having a low heat transport amount, there is a problem that the efficiency of the LNG vaporization process is low. In addition, as in Patent Document 2, in the case where metal fine particles that become frozen nuclei are removed by an electromagnet, complication of the apparatus configuration becomes a problem.

  The present invention has been made in view of the above problems, and an object of the present invention is to prevent the intermediate medium from freezing and improve the efficiency of the low-temperature liquefied gas vaporization process with a simple apparatus configuration. It is to provide a type vaporizer.

  An intermediate medium type vaporizer according to one aspect of the present invention vaporizes the low temperature liquefied gas by transferring heat of a heat source fluid to the low temperature liquefied gas through the intermediate medium. This intermediate medium type vaporizer vaporizes the low-temperature liquefied gas by the intermediate medium heating unit that heats the liquid intermediate medium by the heat of the heat source fluid, and the heat of the intermediate medium heated in the intermediate medium heating unit. And a gas vaporization unit. The intermediate medium has a freezing point higher than the temperature of the low-temperature liquefied gas and contains antifreeze protein.

  In this intermediate medium type vaporizer, an intermediate medium having a freezing point higher than the temperature of the low-temperature liquefied gas is used, so that a refrigerant (such as propane) having a freezing point lower than the temperature of the low-temperature liquefied gas is used as the intermediate medium. Compared to the case, the amount of heat transported by the intermediate medium can be increased. Therefore, the efficiency of the vaporization process of the low-temperature liquefied gas can be improved. In addition, since the antifreeze protein is contained in the intermediate medium, it is possible to prevent the intermediate medium from being cooled and frozen by the low temperature liquefied gas even when an intermediate medium having a higher freezing point than the temperature of the low temperature liquefied gas is used. it can. Therefore, according to the intermediate medium type vaporizer, the intermediate medium can be prevented from freezing and the efficiency of the vaporization process of the low-temperature liquefied gas can be improved by a simple configuration in which the intermediate medium contains the antifreeze protein.

  In the intermediate medium type vaporizer, the intermediate medium may be a medium having a boiling point higher than the temperature of the heat source fluid.

  According to this configuration, since the intermediate medium does not evaporate in the intermediate medium heating unit, it is possible to maintain a state where the antifreeze protein exists in the liquid intermediate medium. Therefore, antifreeze protein can flow together with the liquid intermediate medium, and unlike the case where antifreeze protein exists in the gaseous intermediate medium, antifreeze protein is prevented from sticking to the flow path wall of the intermediate medium. can do.

  In the intermediate medium type vaporizer, the intermediate medium heating unit may be configured to evaporate at least a part of the liquid intermediate medium. Further, the intermediate medium type vaporizer has a dryness measuring unit that measures the dryness of the intermediate medium flowing out from the intermediate medium heating unit, and the dryness measured by the dryness measuring unit is less than 1. And a flow rate adjusting unit that adjusts at least one of a flow rate of the intermediate medium flowing into the intermediate medium heating unit and a flow rate of the heat source fluid in the intermediate medium heating unit.

  According to this configuration, since the dryness of the intermediate medium flowing out from the intermediate medium heating unit is controlled to be less than 1, the liquid intermediate medium can remain even after flowing out from the intermediate medium heating unit. For this reason, it becomes possible to maintain the state in which antifreeze protein exists in a liquid intermediate medium, and it can prevent that antifreeze protein adheres to the channel wall etc. of an intermediate medium as mentioned above.

  The intermediate medium type vaporizer may further include a container having a space in which the intermediate medium can be filled. The intermediate medium heating unit may be configured by a heat source pipe arranged in the space and through which the heat source fluid flows. The gas vaporization unit may be configured by a liquefied gas pipe that is disposed in the space and is positioned above the heat source pipe and into which the low-temperature liquefied gas is introduced.

  According to this configuration, since the natural convection of the intermediate medium can be generated between the high-temperature side heat source pipe and the low-temperature side liquefied gas pipe in the space of the container, the low-temperature from the heat source fluid via the intermediate medium The efficiency of heat transfer to the liquefied gas can be improved. In addition, since the antifreeze protein can be circulated between the heat source pipe and the liquefied gas pipe by the flow of the intermediate medium, the antifreeze protein always exists near the liquefied gas pipe where the intermediate medium can freeze. it can. Thereby, freezing of the intermediate medium by the low-temperature liquefied gas can be reliably prevented.

  The intermediate medium type vaporizer may further include a partition portion that partitions the space into a plurality of regions. The heat source pipe and the liquefied gas pipe may be arranged in each of the plurality of regions.

  According to this configuration, natural convection of the intermediate medium can be generated between the heat source pipe and the liquefied gas pipe in each region partitioned by the partition portion. That is, natural convection can be generated in a narrower region than when natural convection is generated in the entire space of the container, so that natural convection can be promoted.

  The intermediate medium vaporizer may further include a separation unit that allows the intermediate medium to permeate and prevents the antifreeze protein from permeating. The separation unit may be disposed between the heat source pipe and the liquefied gas pipe in the space. The antifreeze protein may be contained in the intermediate medium on the liquefied gas piping side with respect to the separation part.

  According to this configuration, it is possible to cause natural convection of the intermediate medium between the heat source pipe and the liquefied gas pipe, and to prevent the antifreeze protein from flowing toward the heat source pipe by the separation unit. Therefore, since the antifreeze protein can be present only in the vicinity of the liquefied gas pipe, the amount of antifreeze protein added can be reduced.

  The intermediate medium type vaporizer may further include a stirring unit that is disposed in the space and stirs the intermediate medium.

  According to this configuration, since the intermediate medium can be forcibly circulated in the space of the container by stirring, the heat transfer efficiency from the heat source fluid via the intermediate medium to the low-temperature liquefied gas can be improved. Moreover, since the antifreeze protein can be forcedly circulated by the flow of the intermediate medium, it is possible to prevent the antifreeze protein from settling on the bottom of the container.

  In the intermediate medium vaporizer, the intermediate medium may be a nonflammable refrigerant.

  According to this configuration, even when the intermediate medium leaks out of the apparatus, the risk of fire can be avoided.

  As is apparent from the above description, according to the present invention, there is provided an intermediate medium type vaporizer capable of preventing freezing of the intermediate medium and improving the efficiency of the low temperature liquefied gas vaporization process with a simple apparatus configuration. Can be provided.

It is a figure which shows typically the structure of the intermediate medium type vaporizer | carburetor which concerns on Embodiment 1 of this invention. It is a schematic diagram for demonstrating the process in which an ice crystal grows when an antifreeze protein is not contained in an intermediate medium. It is a schematic diagram for demonstrating a mode that the growth of an ice crystal is suppressed when an antifreeze protein is contained in an intermediate medium. It is a schematic diagram which shows partially the structure of the intermediate medium type vaporizer | carburetor which concerns on Embodiment 2 of this invention. It is a flowchart which shows the flow of the dryness control of the intermediate medium performed in the intermediate medium vaporizer | carburetor which concerns on Embodiment 2 of this invention. It is a figure which shows typically the structure of the intermediate medium type vaporizer | carburetor which concerns on Embodiment 3 of this invention. It is a figure which shows typically the structure of the intermediate-medium type vaporizer | carburetor which concerns on the modification 1 of Embodiment 3 of this invention. It is a figure which shows typically the structure of the intermediate medium type vaporizer which concerns on the modification 2 of Embodiment 3 of this invention. It is a figure which shows typically the structure of the intermediate-medium type vaporizer | carburetor which concerns on the modification 3 of Embodiment 3 of this invention. It is a figure which shows typically the structure of the intermediate medium type vaporizer | carburetor which concerns on the modification 4 of Embodiment 3 of this invention.

  Hereinafter, an intermediate medium type vaporizer according to an embodiment of the present invention will be described in detail based on the drawings.

(Embodiment 1)
First, the configuration of the intermediate medium vaporizer 1 according to Embodiment 1 of the present invention will be described with reference mainly to FIG. FIG. 1 schematically shows main components in the intermediate medium type vaporizer 1. The intermediate medium type vaporizer 1 vaporizes the low temperature liquefied gas by transferring the heat of the heat source fluid 3 to the low temperature liquefied gas via the intermediate medium 2. In the present embodiment, the case where the heat source fluid 3 is air and the low-temperature liquefied gas is LNG will be described as an example of the present invention.

  As shown in FIG. 1, the intermediate medium type vaporizer 1 includes an intermediate medium heating unit E1, a gas vaporizing unit E2, a gas heating unit E3, an intermediate medium heating unit E1, and a gas vaporizing unit E2. A circulation path 20 for circulating the medium 2, an LNG introduction path 30 for guiding LNG to the gas vaporization section E2, an NG introduction path 40 for guiding NG flowing out from the gas vaporization section E2 to the gas heating section E3, and a gas heating section NG supply path 50 that mainly guides NG flowing out from E3 to a predetermined demand destination. The circulation path 20 includes a feed-side flow path 23 that sends the liquid intermediate medium 2 from the gas vaporization section E2 to the intermediate medium heating section E1, and a return-side flow path that returns the intermediate medium 2 from the intermediate medium heating section E1 to the gas vaporization section E2. 24.

  The intermediate medium heating unit E1 is a part that heats the liquid intermediate medium 2 with the heat of the heat source fluid 3. The intermediate medium heating unit E1 includes a heat transfer tube 12 in which the intermediate medium 2 flows and a plurality of fins (not shown) are provided along the axial direction.

  The heat transfer tube 12 is connected to the downstream end of the feed-side flow path 23 and is disposed in a posture extending in the horizontal direction or in a direction slightly inclined with respect to the horizontal direction. A blower 11 made of a propeller fan is disposed on the upper side of the heat transfer tube 12. The blower 11 is a push fan, for example, and generates an air flow of the heat source fluid 3 from the blower 11 toward the heat transfer tube 12. The blower 11 operates by driving a motor (not shown) connected to the rotating shaft. The blower 11 and the heat transfer tube 12 are each disposed in a duct in which a flow path of the heat source fluid 3 is formed.

  In addition, the air blower 11 is not limited to the case where it is comprised with a pushing fan, You may be comprised with the suction fan. In this case, an air flow of the heat source fluid 3 is generated from the heat transfer tube 12 toward the blower 11.

  The intermediate medium 2 flows in the heat transfer tube 12 from upstream to downstream, and the heat source fluid 3 is applied to the outer surface of the heat transfer tube 12. As a result, the intermediate medium 2 exchanges heat with the heat source fluid 3 through the heat transfer tube 12 and is heated by the heat of the heat source fluid 3. The heated intermediate medium 2 flows out from the downstream end of the heat transfer tube 12 to the return side flow path 24. In the intermediate medium heating unit E1, seawater may be used as the heat source fluid instead of air.

  The gas vaporization part E2 is a part that vaporizes LNG by the heat of the intermediate medium 2 heated in the intermediate medium heating part E1. The gas vaporizing section E2 is disposed in the space of the shell 21 and is configured by a tube 22 (heat transfer tube) having a U-shaped bent shape. The space of the shell 21 is filled with the intermediate medium 2. In addition, the tube 22 is not limited to the shape bent in the U shape, For example, the tube 22 may have a shape extending linearly.

  An inlet 20A for the intermediate medium 2 is provided on one side wall (right side in FIG. 1) of the shell 21, and an outlet 20B for the intermediate medium 2 is provided on the bottom wall of the shell 21. The downstream end of the return side flow path 24 is connected to the inflow port 20A, and the upstream end of the feed side flow path 23 is connected to the outflow port 20B.

  The tube 22 is arranged so that the upstream end and the downstream end are located on the other side wall (left side in FIG. 1) of the shell 21. The upstream end of the tube 22 is connected to the downstream end of the LNG introduction path 30, and the downstream end of the tube 22 is connected to the upstream end of the NG introduction path 40.

  LNG flows in the tube 22 from upstream to downstream, and the intermediate medium 2 that has flowed into the space of the shell 21 contacts the outer surface of the tube 22. The LNG exchanges heat with the intermediate medium 2 through the tube 22, and the LNG is vaporized by the heat of the intermediate medium 2. Thereby, LNG becomes NG in the middle of flowing through the tube 22. Then, NG flows out from the downstream end of the tube 22 to the NG introduction path 40.

  The gas heating unit E3 is a part that heats the NG obtained in the gas vaporization unit E2 by the heat of the air 5. The gas heating unit E3 is configured by a heat transfer tube 32 that is arranged in a posture extending in a substantially horizontal direction while NG flows. On the upper side of the heat transfer tube 32, a blower 31 composed of a push-in fan or a suction fan is arranged. The downstream end of the NG introduction path 40 is connected to the upstream end of the heat transfer pipe 32, and the upstream end of the NG supply path 50 is connected to the downstream end of the heat transfer pipe 32.

  NG flows in the heat transfer tube 32 from upstream to downstream, and air 5 is applied to the outer surface of the heat transfer tube 32. Thus, the NG is heated by exchanging heat with the air 5 via the heat transfer tube 32. In the intermediate medium type vaporizer of the present invention, the gas heating unit E3 is not an essential component and may be omitted.

The intermediate medium 2 is a refrigerant having a freezing point higher than the temperature of LNG (low temperature liquefied gas). As such an intermediate medium 2, for example, CH ₂ F ₂ (freezing point −136 ° C., boiling point −51.8 ° C., heat transport amount 52.02), C ₂ HF ₅ (freezing point −103 ° C., boiling point −48.6). ° C., heat transport amount 120.03), CH ₃ CF ₃ (freezing point −112 ° C., boiling point −47.2 ° C., heat transport amount 84.00), CF ₃ CH ₂ F (freezing point −103 ° C., boiling point −29. 8 ° C., heat transport amount 102.03), CF ₃ CF═CH ₂ (freezing point −53 ° C., boiling point −29.5 ° C., heat transport amount 114.04), CF ₃ CH═CFH (freezing point −105 ° C., boiling point) -19.0 ° C, heat transport amount 114.04), CF ₃ CHFCF ₃ (freezing point -131 ° C, boiling point -15.6 ° C, heat transport amount 170.03), n-C ₄ H ₈ (freezing point -138 ° C) , boiling point -0.5 ° C., the heat transfer rate 58.13) or _CF 3 C ₃ CHF ₂ (freezing point -103 ° C., boiling point 15.3 ° C., amount of heat transport 134.08) and organic medium such as water (freezing point 0 ° C., boiling point 100 ° C., the heat transfer rate 133.5) be used as the Can do. Since these intermediate media 2 have a higher heat transport amount than the refrigerant having a freezing point lower than the temperature of LNG such as propane (the heat transport amount of propane is 44.10), the efficiency of the LNG vaporization process is improved. Can do.

  Many of the organic media have a boiling point lower than the temperature of the air that is the heat source fluid 3, and water has a boiling point that is higher than the temperature of the air that is the heat source fluid 3. For this reason, when the organic medium is used as the intermediate medium 2, in many cases, at least a part of the intermediate medium 2 evaporates in the intermediate medium heating unit E1. On the other hand, when water is used as the intermediate medium 2, the intermediate medium 2 does not evaporate in the intermediate medium heating section E1.

Of the refrigerants listed above, C ₂ HF ₅ , CF ₃ CH ₂ F, CF ₃ CHFCF ₃ , CF ₃ CH ₃ CHF ₂ and water are all non-flammable refrigerants. When a flammable refrigerant such as propane is used as an intermediate medium, there is a risk of fire when the intermediate medium leaks out of the shell 21, whereas by using the nonflammable refrigerant as described above, the apparatus Can be secured.

  Here, when a refrigerant having a higher freezing point than the temperature of LNG is used as the intermediate medium 2 as described above, freezing of the intermediate medium 2 becomes a problem when the intermediate medium 2 is cooled by LNG in the gas vaporization section E2. . FIG. 2 shows a process in which ice crystals grow when the intermediate medium 2 is cooled by the LNG 6 when water is used as the intermediate medium 2. As shown in FIG. 2, the intermediate medium 2 is cooled by exchanging heat with the LNG 6 via the tube 22, whereby ice nuclei 2 </ b> A are generated in the water. The number of ice nuclei 2A gradually increases, and the ice nuclei 2A are combined to produce ice 2B. As a result, the intermediate medium 2 may be completely frozen, and problems such as channel blockage may occur.

  On the other hand, in the intermediate medium vaporizer 1 according to the present embodiment, the intermediate medium 2 includes antifreeze protein 4 (AFP; Anti Freeze Protein) having an action of suppressing the growth of ice crystals as described above. It is. Therefore, as shown in FIG. 3, although ice nuclei 2A are generated as in the case where antifreeze protein 4 is not included (FIG. 2), the growth of ice nuclei 2A by the action of antifreeze protein 4 (ice nuclei 2A) (Bonding between each other) is suppressed. That is, it is possible to prevent the minute ice nuclei 2A from growing into the huge ice 2B. Therefore, even when a refrigerant having a freezing point higher than the temperature of LNG is used as the intermediate medium 2, it is possible to prevent the intermediate medium 2 from completely freezing and avoid problems such as flow path blockage. Moreover, although the intermediate medium 2 is not completely frozen, the ice nucleus 2A itself is generated, so that the latent heat accompanying the phase change from the liquid to the solid can be used for heat exchange with the LNG. Accordingly, high heat exchange efficiency between the LNG and the intermediate medium 2 can be obtained.

  Antifreeze protein 4 is extracted from various organisms inhabiting cold regions. The types of antifreeze protein 4 include AFGP (antifreeze glycoprotein, protein having a repetitive structure of Ala (alanine) -Ala-Thr (threonine)), type I AFP (single chain consisting of continuous Ala residues). A protein having a helical structure), a type II AFP (a protein having a disulfide molecule having a molecular weight of about 14,000), a type III AFP (a globular protein having a molecular weight of about 6000) and a type IV AFP (a molecular weight of about 12000) Non-helical protein). In addition, the antifreeze protein 4 is not limited to the natural thing extracted from a living body, The artificially synthesized thing may be used.

  Here, the features and operational effects of the intermediate medium type vaporizer 1 according to the first embodiment described above will be listed.

  The intermediate medium type vaporizer 1 according to the first embodiment vaporizes LNG by transferring heat of the heat source fluid 3 to the LNG (low temperature liquefied gas) through the intermediate medium 2. The intermediate medium type vaporizer 1 includes an intermediate medium heating unit E1 that heats the liquid intermediate medium 2 by the heat of the heat source fluid 3, and a gas vaporization that vaporizes LNG by the heat of the intermediate medium 2 heated in the intermediate medium heating unit E1. Part E2. The intermediate medium 2 has a freezing point higher than the temperature of LNG and contains antifreeze protein 4.

  In this intermediate medium type vaporizer 1, since the intermediate medium 2 having a freezing point higher than the temperature of LNG is used, compared with a case where a refrigerant (for example, propane) having a freezing point lower than the temperature of LNG is used as the intermediate medium, The amount of heat transport by the intermediate medium can be increased. Therefore, the efficiency of the LNG vaporization process can be improved. In addition, by including the antifreeze protein 4 in the intermediate medium 2, even when the intermediate medium 2 having a higher freezing point than the temperature of LNG is used, the intermediate medium 2 can be prevented from being cooled and frozen by the LNG. it can. Therefore, according to the intermediate medium type vaporizer 1, the intermediate medium 2 can be prevented from freezing and the efficiency of the LNG vaporization process can be improved by a simple configuration in which the intermediate medium 2 contains the antifreeze protein 4. .

  In the intermediate medium type vaporizer 1, the intermediate medium 2 may be a medium (for example, water) having a boiling point higher than the temperature of the heat source fluid 3 that is air. In this case, since the intermediate medium 2 does not evaporate in the intermediate medium heating part E1, the state where the antifreeze protein 4 exists in the liquid intermediate medium 2 can be maintained. Therefore, since the antifreeze protein 4 can flow together with the liquid intermediate medium 2, unlike the case where the antifreeze protein 4 exists in the gaseous intermediate medium, the antifreeze protein 4 adheres to the flow path wall of the intermediate medium. Can be prevented.

  In the intermediate medium type vaporizer 1, the intermediate medium 2 may be a nonflammable refrigerant. Thereby, even if it is a case where the intermediate medium 2 leaks out of the shell 21, the circulation path 20, or the heat exchanger tube 12, the danger of a fire can be avoided.

(Embodiment 2)
Next, an intermediate medium vaporizer 1A according to Embodiment 2 of the present invention will be described with reference mainly to FIG. The intermediate medium type vaporizer 1A according to the second embodiment basically has the same configuration as the intermediate medium type vaporizer 1 according to the first embodiment, but flows out from the intermediate medium heating unit E1 (heat transfer tube 12). This is different from the first embodiment in that a mechanism for controlling the dryness of the intermediate medium is provided. Only differences from the first embodiment will be described below.

In the second embodiment, a medium having a boiling point lower than the temperature of the heat source fluid 3 that is air is used as the intermediate medium. Specifically, as listed in the first embodiment, for example, CH ₂ F ₂ , C ₂ HF ₅ , CH ₃ CF ₃ , CF ₃ CH ₂ F, CF ₃ CF═CH ₂ , CF ₃ CH═CFH, CF Organic media such as ₃ CHFCF ₃ , n-C ₄ H ₈ or CF ₃ CH ₃ CHF ₂ are used. For this reason, at least a part of the liquid intermediate medium evaporates due to heat exchange between the liquid intermediate medium and the heat source fluid 3 in the intermediate medium heating section E1.

  As shown in FIG. 4, an intermediate medium pump 25 that feeds the liquid intermediate medium toward the intermediate medium heating unit E <b> 1 is provided in the feed side flow path 23. A gas-liquid separator 80 for gas-liquid separation of the intermediate medium flowing out from the intermediate medium heating unit E1 is disposed in the return side flow path 24. The gas-liquid separator 80 is provided with an intermediate medium inlet 80A, a gas side outlet 80B through which the gaseous intermediate medium flows out, and a liquid side outlet 80C through which the liquid intermediate medium flows out. Yes. The return-side channel 24 includes an outflow channel 26 connected to the downstream end of the heat transfer tube 12 and the inlet 80A of the gas-liquid separator 80, a gas-side channel 27 connected to the gas-side outlet 80B, And a liquid side channel 28 connected to the liquid side outlet 80C. The gas side flow path 27 and the liquid side flow path 28 are connected to the gas vaporization section E2 after joining into one flow path.

  The intermediate medium vaporizer 1A includes a dryness measuring unit 60 that measures the dryness of the intermediate medium flowing out from the intermediate medium heating unit E1. The dryness measurement unit 60 measures the flow rate of the liquid intermediate medium flowing through the feed side flow path 23 and the first flow rate measurement unit 61 that measures the flow rate of the gaseous intermediate medium flowing through the gas side flow path 27. 2 stores flow rate measurement unit 62, third flow rate measurement unit 63 that measures the flow rate of the liquid intermediate medium flowing through liquid side flow path 28, and information of measurement results by first to third flow rate measurement units 61 to 63. A storage unit 29 and a calculation unit 29A that calculates the dryness of the intermediate medium based on each measurement result stored in the storage unit 29 are included.

  The first to third flow rate measuring units 61 to 63 are flow meters, and are respectively disposed in the feed side channel 23, the gas side channel 27, and the liquid side channel 28 as shown in FIG. Hereinafter, the flow rate of the liquid intermediate medium on the inlet side of the intermediate medium heating unit E1 measured by the first flow rate measuring unit 61 is “Q1”, and the outlet side of the intermediate medium heating unit E1 measured by the second flow rate measuring unit 62 The flow rate of the gaseous intermediate medium at “Q2” and the flow rate of the liquid intermediate medium at the outlet side of the intermediate medium heating unit E1 measured by the third flow rate measuring unit 63 will be described as “Q3”.

  Data of measurement results from the first to third flow rate measuring units 61 to 63 is transmitted to the storage unit 29. The calculation unit 29A obtains data of Q1 to Q3 by accessing the storage unit 29, and calculates the value of “Q2 / Q1”, thereby calculating the dryness of the intermediate medium flowing out from the intermediate medium heating unit E1. To do.

  The intermediate medium type vaporizer 1A has a flow rate of the liquid intermediate medium flowing into the intermediate medium heating unit E1 and an intermediate medium heating unit E1 so that the dryness of the intermediate medium measured by the dryness measuring unit 60 is less than 1. Is provided with a flow rate adjusting unit 70 for adjusting at least one of the flow rates of the heat source fluid 3. The flow rate adjusting unit 70 is a controller capable of controlling the power of the intermediate medium pump 25 and the rotation speed of the blower 11 in the intermediate medium heating unit E1, and controls each device based on the dryness of the intermediate medium calculated by the calculation unit 29A. Control.

  Specifically, when the dryness of the intermediate medium flowing out from the intermediate medium heating unit E1 is 1, the flow rate adjusting unit 70 flows into the intermediate medium heating unit E1 by increasing the power of the intermediate medium pump 25. The flow rate of the heat source fluid 3 in the intermediate medium heating unit E1 is decreased by increasing the flow rate of the intermediate medium or decreasing the fan rotation speed of the blower 11. This reduces the dryness of the intermediate medium. On the other hand, when the dryness of the intermediate medium flowing out from the intermediate medium heating unit E1 is less than a predetermined lower limit (for example, 0.8), the flow rate adjusting unit 70 reduces the power of the intermediate medium pump 25 to reduce the intermediate medium pump 25. The flow rate of the heat source fluid 3 in the intermediate medium heating unit E1 is increased by decreasing the flow rate of the intermediate medium flowing into the medium heating unit E1 or increasing the fan rotation speed of the blower 11. This prevents the evaporation amount of the intermediate medium from being excessively reduced.

  FIG. 5 shows an example of a control flow of the dryness of the intermediate medium flowing out from the intermediate medium heating unit E1. First, by operating the intermediate medium pump 25, the liquid intermediate medium is caused to flow into the intermediate medium heating part E1 through the feed side flow path 23 (ST1).

  Next, the flow rates Q1 and Q3 are stored in the storage unit 29 (ST2). Subsequently, it is determined whether or not the flow rate Q3 is larger than 0 (ST3). Here, when the flow rate Q3 is larger than 0, the dryness of the intermediate medium flowing out from the intermediate medium heating unit E1 is less than 1, and when the flow rate Q3 is 0, the intermediate medium flowing out from the intermediate medium heating unit E1 is dried. The degree is 1 or overheated.

  When Q3 = 0 (“NO” in ST3), it is determined whether or not the flow rate of the intermediate medium flowing into the intermediate medium heating unit E1 is maximum (ST4). If the flow rate of the intermediate medium is not maximum (“NO” in ST4), the flow rate of the intermediate medium is increased by increasing the power of the intermediate medium pump 25 (ST5). On the other hand, when the flow rate of the intermediate medium is maximum (YES in ST4), the flow rate of the heat source fluid 3 in the intermediate medium heating unit E1 is decreased by lowering the fan rotation speed of the blower 11 (ST6).

  On the other hand, if Q3> 0 (“YES” in ST3), the flow rates Q1 and Q2 are stored in the storage unit 29 (ST7). Subsequently, the calculation unit 29A calculates the value of the dryness (Q2 / Q1) of the intermediate medium, and determines whether this value is equal to or greater than a predetermined lower limit (for example, 0.8) (ST8).

  If Q2 / Q1 <0.8 (“NO” in ST8), it is determined whether or not the flow rate of the intermediate medium flowing into the intermediate medium heating unit E1 is the minimum (ST9). If the flow rate of the intermediate medium is not minimum (“NO” in ST9), the flow rate of the intermediate medium is decreased by reducing the power of the intermediate medium pump 25 (ST10). On the other hand, when the flow rate of the intermediate medium is minimum (YES in ST9), the flow rate of the heat source fluid 3 in the intermediate medium heating unit E1 is increased by increasing the fan rotation speed of the blower 11 (ST11).

  As described above, in the intermediate medium vaporizer 1A according to the second embodiment, at least a part of the liquid intermediate medium is evaporated in the intermediate medium heating unit E1, and the dryness of the intermediate medium flowing out from the intermediate medium heating unit E1 is determined. Can be controlled to be less than 1. As a result, the liquid intermediate medium can remain even after flowing out from the intermediate medium heating section E1. For this reason, it becomes possible to maintain the state in which the antifreeze protein 4 exists in the liquid intermediate medium, and the antifreeze protein 4 adheres to the flow path wall (for example, the inner wall surface of the return side flow path 24) of the intermediate medium. Can be prevented. Further, by controlling the lower limit value of the dryness of the intermediate medium, it is possible to maintain high heat exchange efficiency in the intermediate medium heating unit E1.

The dryness of the intermediate medium is not limited to the case where it is calculated using the flow rates Q1 and Q2 as described above, and can also be calculated using the following equations (1) and (2). In the following formula (1), “Q” indicates the exchange heat quantity (W) between the heat source fluid 3 (air) and the intermediate medium, and “ha” indicates the heat transfer coefficient (W / m ² · K) of air. , “Ta” indicates air temperature (K), “T1” indicates intermediate medium inlet temperature (K), “T2” indicates intermediate medium outlet temperature (K), and “A” indicates heat transfer tube A surface area (m ² ) of 12 is shown. In the following formula (2), “Q2” indicates the dryness of the intermediate medium, “Qp” indicates the mass flow rate (kg / s) of the intermediate medium flowing through the outflow passage 26, and “L” indicates the intermediate medium. Latent heat (J / kg) is shown.

(Embodiment 3)
Next, an intermediate medium vaporizer 1B according to Embodiment 3 of the present invention will be described with reference to FIG. As shown in FIG. 6, the intermediate medium type vaporizer 1 </ b> B includes a container 91 having a space 91 </ b> A that can be filled with a liquid intermediate medium 2, and a heat source pipe 92 that is disposed in the space 91 </ b> A and through which seawater as a heat source fluid flows. (Heat transfer pipe) and a liquefied gas pipe 93 (heat transfer pipe) that is disposed in the space 91A and positioned above the heat source pipe 92 and into which LNG (low temperature liquefied gas) is introduced.

  The heat source pipe 92 extends linearly from one side wall 91B of the container 91 toward the other side wall 91C. The liquefied gas pipe 93 has a U-shaped bent shape, and is arranged with a space from the heat source pipe 92. As shown in FIG. 6, the liquefied gas pipe 93 includes first and second pipe portions 93A and 93B extending linearly in a direction in which both side walls 91B and 91C of the container 91 are opposed (lateral direction in FIG. 6). 1 and the connection part 93C which connects the edge parts of 2nd piping part 93A, 93B. In the first piping portion 93A, LNG before vaporization mainly flows from left to right in FIG. The second piping portion 93B is located above the first piping portion 93A. In the second pipe portion 93B, NG mainly vaporized flows from the right to the left in FIG. Note that the liquefied gas pipe 93 is not limited to a U-shaped bent pipe as shown in FIG. 6, and may be a single pipe that extends in a straight line like the heat source pipe 92.

  In this intermediate medium type vaporizer 1 </ b> B, the intermediate medium heating part E <b> 1 is constituted by a heat source pipe 92, and the gas vaporization part E <b> 2 is constituted by a liquefied gas pipe 93. In the intermediate medium heating unit E1, the liquid intermediate medium 2 in the space 91A is heated by the heat of seawater (heat source fluid) flowing in the heat source pipe 92. On the other hand, in the gas vaporizing section E2, LNG flowing through the liquefied gas pipe 93 is vaporized by the heat of the intermediate medium 2 heated by the heat of seawater, and NG is obtained.

  In the intermediate medium type vaporizer 1B, natural convection of the intermediate medium 2 can be generated in the space 91A due to a temperature difference between the heat source pipe 92 and the liquefied gas pipe 93. That is, as shown by an arrow in FIG. 6, the liquid intermediate medium 2 can be circulated between the heat source pipe 92 and the liquefied gas pipe 93. Thereby, the heat transfer efficiency from the heat source fluid (seawater) through the intermediate medium 2 to the LNG can be improved without forcibly circulating the intermediate medium 2.

  Moreover, since the antifreeze protein 4 can be circulated between the heat source pipe 92 and the liquefied gas pipe 93 along with the flow of the intermediate medium 2, the antifreeze protein is located near the liquefied gas pipe 93 where the intermediate medium 2 can be frozen. 4 can always be present. Thereby, it is possible to reliably prevent the intermediate medium 2 from being frozen by LNG.

  Hereinafter, various modifications of the intermediate medium type vaporizer according to the third embodiment will be described with reference to FIGS.

(Modification 1)
As shown in FIG. 7, the intermediate medium type vaporizer 1C according to Modification 1 includes a partition portion 94 that partitions the space 91A of the container 91 into a plurality of regions 91AA, 91AB, 91AC. The partition portion 94 is composed of a first partition portion 94A composed of a wall body that connects the upper wall 91D and the bottom wall 91E of the container 91, and a wall body that connects the upper wall 91D and the bottom wall 91E. And a second partition portion 94B that is disposed at an interval from the first partition portion 94A in the direction in which the side walls 91B and 91C face each other.

  By arranging these first and second partition portions 94A and 94B, the space 91A of the container 91 is divided into three regions 91AA, 91AB, and 91AC. As shown in FIG. 7, the first region 91AA is a region surrounded by the upper wall 91D, the bottom wall 91E, the other side wall 91C, and the first partition portion 94A. The second region 91AB is a region surrounded by the upper wall 91D, the bottom wall 91E, the first partition portion 94A, and the second partition portion 94B. The third region 91AC is a region surrounded by the upper wall 91D, the bottom wall 91E, the second partition portion 94B, and the one side wall 91B.

  As shown in FIG. 7, a heat source pipe 92 and a liquefied gas pipe 93 are arranged in each of the plurality of regions 91AA, 91AB, 91AC. In other words, the heat source pipe 92 and the liquefied gas pipe 93 are arranged in the space 91A so as to cover all of the plurality of regions 91AA, 91AB, 91AC. For this reason, natural convection of the intermediate medium 2 is generated in each of the regions 91AA, 91AB, 91AC, and the antifreeze protein 4 can be circulated between the heat source pipe 92 and the liquefied gas pipe 93. That is, as shown in FIG. 6, natural convection can be generated in a narrower region than in the case where one natural convection is generated over the entire space 91 </ b> A, and thus natural convection can be promoted. Become.

  Note that the first and second partition portions 94A and 94B are not limited to the case where the first partition portion 94A and the second partition portion 94B are made of a wall as in the present modification. For example, a plurality of flow resistors that provide resistance to the flow of the liquid intermediate medium 2 (Not shown) may be arranged in the vertical direction of the container 91. Even in this case, natural convection of the intermediate medium 2 can be caused in each of the plurality of regions 91AA, 91AB, 91AC as shown in FIG. Further, the space 91A is not limited to the case where it is divided into three regions as in the present modification, and may be divided into two regions or may be divided into four or more regions.

(Modification 2)
As shown in FIG. 8, the intermediate medium type vaporizer 1D according to the modification 2 includes a separation unit 95 disposed between the heat source pipe 92 and the liquefied gas pipe 93 in the space 91A. The separation unit 95 divides the space 91A into a heat source side space 91AD in which the heat source pipe 92 is disposed and a liquefied gas side space 91AE in which the liquefied gas pipe 93 is disposed.

  The separation unit 95 is, for example, an ultrafiltration membrane, and has a function of allowing permeation of the liquid intermediate medium 2 and preventing permeation of the antifreeze protein 4. That is, the filtration membrane constituting the separation unit 95 can pass liquid and has a pore diameter smaller than that of the antifreeze protein 4. Separation part 95 connects one side wall 91B of container 91 and the other side wall 91C. As shown in FIG. 8, the antifreeze protein 4 is contained in the intermediate medium 2 in the space on the liquefied gas pipe 93 side (liquefied gas side space 91 AE) with respect to the separation unit 95, and is separated from the separation unit 95. Therefore, it is not included in the intermediate medium 2 in the space on the heat source pipe 92 side (the heat source side space 91AD).

  In this modified example, natural convection of the intermediate medium 2 can be generated between the heat source pipe 92 and the liquefied gas pipe 93 and the antifreeze protein 4 flows toward the heat source pipe 92 by the separation unit 95. Can be blocked. Accordingly, since the antifreeze protein 4 can be present only in the vicinity of the liquefied gas pipe 93 where freezing of the intermediate medium 2 is a problem, the amount of antifreeze protein 4 added can be reduced. Since the antifreeze protein 4 is expensive, there is a great advantage in providing the separation part 95 as in this modification and adding the antifreeze protein 4 only to the necessary space region.

(Modification 3)
FIG. 9 shows a configuration of an intermediate medium vaporizer 1E according to the third modification. As shown in FIG. 9, the intermediate medium type vaporizer 1 </ b> E has a configuration in which the partition portion 94 described in the first modification example and the separation unit 95 described in the second modification example are combined. For this reason, in the modified example 3, the effect of promoting the natural convection of the intermediate medium 2 and the effect of reducing the addition amount of the antifreeze protein 4 are obtained.

(Modification 4)
As shown in FIG. 10, the intermediate medium type vaporizer 1 </ b> F according to the modification 4 is disposed in the space 91 </ b> A of the container 91 and includes a stirring unit 96 that stirs the intermediate medium 2. The stirring unit 96 includes a rotating shaft 96A and a plurality of stirring blades 96B attached to the rotating shaft 96A. By rotating the rotary shaft 96A with a motor (not shown) or the like, the intermediate medium 2 filled in the space 91A can be stirred by the stirring blade 96B.

  By stirring the intermediate medium 2 with the stirring blade 96B, in addition to the effect of natural convection due to the temperature difference between the heat source pipe 92 and the liquefied gas pipe 93, the intermediate medium 2 can be forcibly circulated in the space 91A. . Thereby, the heat transfer efficiency from the heat source fluid through the intermediate medium 2 to the LNG can be further improved. In addition, since the antifreeze protein 4 can be forcibly circulated by the flow of the intermediate medium 2, it is possible to prevent the antifreeze protein 4 from sinking to the bottom of the container 91.

  In addition, it is not limited to the case where only one stirring unit 96 is arranged in the container 91 as in the present modification, and the space 91A is divided into a plurality of regions 91AA, 91AB, and 91AC as in the first modification (FIG. 7). In addition to the division, the agitator 96 may be disposed in each of the regions 91AA, 91AB, 91AC. And you may further combine the isolation | separation part 95 demonstrated in the said modification 2 (FIG. 8).

(Other embodiments)
Finally, other embodiments of the present invention will be described.

  In the first to third embodiments, the case where LNG is vaporized as an example of the low-temperature liquefied gas has been described. However, the present invention is not limited to this. The intermediate medium vaporizer of the present invention may be used to vaporize other low temperature liquefied gases such as ethylene, liquefied oxygen or liquefied nitrogen.

  In the first embodiment, the case where the gas vaporization section E2 is formed of a shell and tube heat exchanger has been described. However, the present invention is not limited to this, and may be formed of, for example, a plate heat exchanger. In this case, the gas vaporization part E2 can be made more compact.

  It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1, 1A, 1B, 1C, 1D, 1E, 1F Intermediate medium type vaporizer 2 Intermediate medium 3 Heat source fluid 4 Antifreeze protein 60 Dryness measuring unit 70 Flow rate adjusting unit 91 Container 91A Space 91AA First region 91AB Second region 91AC Third region 92 Heat source piping 93 Liquefied gas piping 94 Partition portion 94A First partition portion 94B Second partition portion 95 Separating portion 96 Stirring portion E1 Intermediate medium heating portion E2 Gas vaporizing portion

Claims (8)

An intermediate medium type vaporizer that vaporizes the low temperature liquefied gas by transferring heat of the heat source fluid to the low temperature liquefied gas through the intermediate medium,
An intermediate medium heating unit that heats the liquid intermediate medium by the heat of the heat source fluid;
A gas vaporization unit that vaporizes the low-temperature liquefied gas by heat of the intermediate medium heated in the intermediate medium heating unit,
The intermediate medium type vaporizer characterized in that the intermediate medium has a freezing point higher than the temperature of the low-temperature liquefied gas and contains antifreeze protein.   The intermediate medium vaporizer according to claim 1, wherein the intermediate medium has a boiling point higher than a temperature of the heat source fluid. The intermediate medium heating unit is configured to evaporate at least a part of the liquid intermediate medium,
A dryness measuring unit for measuring the dryness of the intermediate medium flowing out of the intermediate medium heating unit;
Adjust at least one of the flow rate of the intermediate medium flowing into the intermediate medium heating unit and the flow rate of the heat source fluid in the intermediate medium heating unit so that the dryness measured by the dryness measurement unit is less than 1 The intermediate medium type vaporizer according to claim 1, further comprising a flow rate adjusting unit that performs the operation. A container having a space capable of being filled with the intermediate medium;
The intermediate medium heating unit is arranged in the space and is configured by a heat source pipe through which the heat source fluid flows,
The gas vaporization unit is disposed in the space and is located above the heat source pipe, and is configured by a liquefied gas pipe into which the low-temperature liquefied gas is introduced. The intermediate medium type vaporizer according to 2. Further comprising a partition for partitioning the space into a plurality of regions;
The intermediate medium vaporizer according to claim 4, wherein the heat source pipe and the liquefied gas pipe are arranged in each of the plurality of regions. A separation unit that allows permeation of the intermediate medium and prevents permeation of the antifreeze protein;
The separation unit is disposed between the heat source pipe and the liquefied gas pipe in the space,
The intermediate medium vaporizer according to claim 4 or 5, wherein the antifreeze protein is contained in the intermediate medium on the liquefied gas piping side with respect to the separation part.   The intermediate medium type vaporizer according to any one of claims 4 to 6, further comprising a stirring unit that is disposed in the space and stirs the intermediate medium.   The intermediate medium vaporizer according to claim 1, wherein the intermediate medium is a nonflammable refrigerant.

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