JP5965281B2 - Flowing film evaporation heat exchanger - Google Patents

Description

  The present invention relates to a falling liquid film evaporation type heat exchanger for exchanging latent heat of vaporization for vaporizing a liquefied gas fluid on the low temperature side and sensible heat of the high temperature side liquid fluid, and in particular, a circulating refrigerant for equipment that needs to maintain a low temperature. A heat exchanger that uses the latent heat of vaporization of the liquefied gas fluid in the cooling device, or the liquefied natural gas vaporization and supply device that vaporizes liquefied natural gas and supplies it as fuel, with the purpose of heat exchange being the opposite. The present invention relates to a heat exchanger to be used and a falling liquid film evaporation heat exchanger used as a refrigerant evaporator placed as a component of a refrigerator.

  Conventionally, in a small gas supply base, a hot water tank type vaporizer using warm water as a heating source is known as a heat exchanger for vaporizing liquefied natural gas (see, for example, Patent Document 1). This vaporizer has a structure in which a long tube for flowing liquefied natural gas is accommodated in the water of a hot water tank, and vaporizes liquefied natural gas flowing in the tube from the hot water outside the tube by heat transfer heating. However, in this system, the heat transfer efficiency is poor because the warm water outside the tube is almost stationary and the flow is gentle. Furthermore, since the liquefied natural gas in the pipe is a gas-liquid mixed phase two-phase flow, the heat transfer efficiency is still poor. For this reason, the overall heat transfer coefficient representing the overall heat transfer efficiency is extremely small, and a large heat transfer area, that is, a long heat transfer tube is required to obtain a complete vaporized gas up to the liquid droplets in the gas-liquid two-phase flow. And As a result, the heat exchanger has a very large volume and weight in order to accommodate long heat transfer tubes.

  Moreover, a falling liquid film evaporator is known as a heat exchanger that evaporates liquid and has good heat transfer efficiency (see, for example, Patent Document 2). This evaporator causes liquid to flow down from above along the inner surface of a vertically arranged straight pipe, and evaporates the falling liquid by heating from the outer surface of the pipe. The heat source outside the tube is generally based on the latent heat of steam, but is also known to be based on sensible heat. These conventional falling film evaporation type heat exchangers are used under the condition that the temperature difference between the high temperature side and the low temperature side is small, and the upper and lower ends of the straight pipe are fixed by a body tube plate. On the other hand, when the liquid to be evaporated is a liquefied gas, for example, the boiling point of liquefied nitrogen is -196 ° C and the boiling point of liquefied natural gas is -161 ° C, which is very low, and the temperature difference from the high temperature liquid outside the tube is very large due to thermal distortion Difficulties arise.

JP 2001-201279 A. JP 2007-178034 A.

  As described above, the conventional tank type vaporizer has a problem that it becomes a large structure. That is, since only a small heat transfer coefficient can be obtained, a large heat transfer area is required.

  On the other hand, there is a conventional falling film evaporation as a heat exchange method with good heat transfer efficiency, but in the case of a liquefied gas vaporizer, there is a large temperature difference between the high temperature heating side near ambient temperature and the ultra low temperature liquefied gas from -100 to -200 ° C. It is difficult to use as it is because of thermal distortion caused by

  Therefore, by using an efficient heat transfer method, it is possible to make a small structure with a small heat transfer area, eliminate the problem of thermal distortion when using an ultra-low temperature liquefied gas fluid, and the structure is simple and manufactured. The technical problem which should be solved in order to obtain an easy falling film evaporation type heat exchanger arises, and this invention aims at solving this problem.

  The present invention has been proposed in order to achieve the above-mentioned object, and the invention according to claim 1 is a flow which evaporates a low-temperature liquefied gas into a low-temperature vaporized gas by heat transfer heating from the high-temperature liquid fluid to the low-temperature liquefied gas fluid. In the liquid film evaporation type heat exchanger, the heat exchanger includes an inner cylinder heat transfer tube having a closed bottom surface, an outer cylinder jacket accommodating and arranging the inner cylinder heat transfer tube, the inner cylinder heat transfer tube, and the A flow path formed by the gap between the outer wall of the inner cylinder heat transfer tube and the inner wall of the outer cylinder jacket. And the low temperature liquefied gas fluid is caused to flow down from the upper liquid reservoir housing along the inner wall surface of the inner tube heat transfer tube, and the inner tube heat transfer tube serves as a heat transfer surface. The low-temperature vaporized gas that evaporates by heat heating Providing falling film evaporator heat exchanger to be discharged upward heat transfer tube.

  According to this configuration, when using a low-temperature liquefied gas fluid in a falling film heat exchanger with good heat transfer efficiency, there is a problem of thermal distortion, but as a means to avoid thermal distortion, the lower end surface is closed as an inner tube heat transfer tube. The inner tube heat transfer tube is used, and the outer tube jacket is supported by one end fixed only by the upper liquid reservoir housing, thereby eliminating the problem of thermal distortion due to the temperature difference between the inner tube heat transfer tube and the outer tube jacket. . Also, the low-temperature liquefied gas fluid to be vaporized is caused to flow vertically from the upper liquid reservoir housing along the inner wall surface of the inner tube heat transfer tube in the same manner as the conventional falling film method, and is vaporized by heating from the outer wall surface of the inner tube heat transfer tube. The gas thus vaporized is discharged from above. As described above, the invention according to claim 1 enables a falling liquid film evaporation type heat exchanger that avoids the problem of thermal distortion.

  The overall heat transfer coefficient that represents the overall heat transfer efficiency of the heat exchanger is the combined value of the heat transfer coefficient in the tube of the inner tube heat transfer tube and the heat transfer coefficient outside the tube. Since boiling evaporation in the liquid film type can obtain a very large heat transfer coefficient, the heat transfer coefficient on the high-temperature liquid flow side outside the inner tube heat transfer tube becomes the rate-determining factor, and the problem of how to secure this value continues. It becomes. In order to increase the heat transfer coefficient in the liquid flow on the tube surface, it is necessary to sufficiently increase the liquid flow rate. Accordingly, in claim 2, a partition plate is provided in a gap between the inner tube heat transfer tube through which the high temperature side liquid fluid is passed and the outer tube jacket so that the liquid flow passes through the flow path of the high temperature side liquid flow. By dividing so as to narrow the cross-sectional area, a high flow rate is ensured uniformly while avoiding uneven flow over the entire heat transfer surface. As described above, it is possible to achieve a small falling liquid film evaporation heat exchanger for liquefied gas evaporation, achieving a small heat transfer area with a high heat transfer coefficient while avoiding the problem of thermal distortion.

  Furthermore, for the partition plate for finely dividing the flow path of the high-temperature side liquid flow, the flow path of the liquid flow is surrounded by the outer wall of the inner tube heat transfer tube, the inner wall of the outer tube jacket, and the partition plate. The mutual contact portions of the outer wall of the tube heat transfer tube, the inner wall of the outer tube jacket, and the partition plate do not necessarily need to be in close contact with each other, and even if there is a slight gap, there is almost no influence on achieving the intended purpose. Most of the liquid flow flows in the direction of the formed flow path, and a very small amount of liquid leaks through the gap where the pressure difference is only small. Therefore, the structure in which the partition plate is supported and fixed by the support rod from the inner tube heat transfer tube, the outer tube jacket, or the upper upper liquid reservoir housing is presented as claims 3, 4 and 5. As a result, the inner tube heat transfer tube and the outer tube jacket, where the temperature difference is large and thermal distortion becomes a problem, are not constrained to each other except at the upper end, and the partition plate can be easily and freely arranged. The simple structure of inserting and assembling the inner tube heat transfer tube into the outer tube jacket can achieve the problem of realizing easy production.

  The falling liquid film evaporation type heat exchanger of the present invention is very compact as compared with the conventional heat exchange for vaporizing a low-temperature liquefied gas fluid, so that the installation area and space can be reduced. Is obtained. Moreover, since it is lightweight, the foundation or mount for installing this heat exchanger can be obtained simply and inexpensively. Furthermore, since it is easy to manufacture with a simple structure, it is possible to obtain an effect that the material cost and design / manufacturing cost of the heat exchanger can be reduced.

The 1st Example of the falling liquid film evaporation type heat exchanger which concerns on embodiment of this invention is shown, (a) is sectional drawing of the heat exchanger, (b) is the flow of the high temperature side liquid flow in the heat exchanger The schematic diagram explaining a path. The principal part decomposition | disassembly sectional drawing of the falling liquid film evaporation type heat exchanger which is 1st Example same as the above. Operation | movement explanatory drawing of the falling liquid film evaporation type heat exchanger which is 1st Example same as the above. The schematic diagram explaining the 1st modification of the flow path of the high temperature side liquid flow in the falling liquid film evaporation type heat exchanger which is 1st Example same as the above. The schematic diagram explaining the 2nd modification of the flow path of a high temperature side liquid flow same as the above. The schematic diagram explaining the 3rd modification of the flow path of a high temperature side liquid flow same as the above. Sectional drawing of the falling liquid film evaporation type heat exchanger shown as 2nd Example of embodiment of this invention. The schematic diagram of the AA cross section of FIG. Operation | movement explanatory drawing of the falling liquid film evaporation type heat exchanger which is 2nd Example same as the above.

  The present invention can be made into a small structure with a small heat transfer area by adopting an efficient heat transfer system, eliminates the problem of thermal distortion when using ultra-low temperature liquefied gas, and has a simple structure and can be manufactured. In order to achieve the object of providing an easy falling liquid film evaporation heat exchanger, the following is considered.

  In order to reduce the size, it is important to first increase the heat transfer efficiency and reduce the necessary heat transfer area for the heat transfer load. In order to increase the overall heat transfer coefficient representing the degree of the overall heat transfer efficiency of the heat exchanger, it is necessary to adopt a method or a measure for increasing the film heat transfer coefficient on both the high temperature side and the low temperature side.

  First, falling film boiling heat transfer is known as a method for ensuring a large film heat transfer coefficient on the low temperature liquefied gas evaporation side. Furthermore, the falling liquid film boiling heat transfer includes a method in which the liquid flows down from the top to the outer surface of the heat transfer tube arranged horizontally, and a method in which the liquid flows from the top to the outer surface of the heat transfer tube arranged vertically. In the present invention, a method is adopted in which the liquid flows from the top to the inner surface of the heat transfer tubes arranged vertically as the simplest and most stable falling liquid film.

  As described in paragraph 0003, in the falling film evaporation heat exchanger using low-temperature liquefied gas, the temperature difference between the inner tube heat transfer tube and the outer tube jacket is very large, so the upper and lower ends are fixed due to thermal distortion problems. There are difficulties. Therefore, in the falling liquid film evaporation heat exchanger of the present invention using a low-temperature liquefied gas, the inner cylinder heat transfer tube whose lower end face is closed and the outer cylinder jacket are joined and held only at the upper end in the upper liquid reservoir housing. The side surface and the bottom surface were made non-bonded with each other to avoid the problem of thermal distortion. In this case, the low-temperature vaporized gas evaporated in the inner cylinder heat transfer tube is exhausted above the inner cylinder. The embodiment of claim 1 as described above.

  Subsequently, in order to ensure a large film heat transfer coefficient on the high temperature liquid fluid side, it is important to increase the degree of turbulence of the high temperature liquid in contact with the heat transfer surface, that is, to increase the flow velocity. In order to increase the flow velocity at a predetermined liquid flow rate, it is necessary to reduce the flow path cross-sectional area. As a measure for achieving this in the configuration of the first aspect, it may be possible to simply narrow the gap between the inner tube heat transfer tube and the outer tube jacket, but there is a difficulty in manufacturing work, and a drift is likely to occur. There is also concern that it will not be effective. Therefore, the best measure is not to narrow the gap, but to finely divide the gap to narrow the liquid flow passage cross-sectional area in the flow path of the high temperature side liquid flow, that is, to create a so-called elongated flow path, so that a wide range of heat transfer tube surface A high flow rate can be realized uniformly over the entire area. The embodiment of claim 2 as described above.

  Therefore, according to the first and second aspects, a compact heat exchanger with a small required heat transfer area can be achieved.

  Subsequently, regarding the installation of the partition plate for forming the flow path, the partition plate provided in the gap between the inner tube heat transfer tube and the outer tube jacket is not necessarily completely fixed to the inner tube heat transfer tube and the outer tube jacket. There is no need to keep it. Even if there is a minute gap between the inner wall of the outer cylinder jacket or the outer cylinder wall of the inner cylinder heat transfer tube and the partition plate, the amount of liquid that leaks through the minute gap because the differential pressure between the adjacent flow paths partitioned by the partition plate is small Since most of the liquid fluid flows according to the flow path formed by the partition plate, the object of securing a large heat transfer coefficient with a high liquid flow rate is achieved. Therefore, as a method of installing the partition plate, a method of supporting and fixing from the inner cylinder heat transfer tube toward the outside thereof, a method of supporting and fixing from the outer tube jacket toward the inside thereof, or an upper liquid reservoir housing above the inner cylinder heat transfer tube A method of extending a support like a bar from below to thereby support and fix the partition plate is presented. With these installation methods, when the apparatus is completed, an arbitrary flow path shape is easily formed in advance by the above method with a partition plate disposed in a closed space surrounded by the inner tube heat transfer tube and the outer tube jacket. After installation, the inner tube heat transfer tube can be inserted into the outer tube jacket and assembled, and the object of easy production with a simple structure is also achieved. The embodiments of claims 3, 4 and 5 as described above.

  Regarding the size and shape of the falling film evaporation heat exchanger described above, the simplest form is that one inner tube heat transfer tube is arranged concentrically with the outer tube jacket, and a partition plate is provided on the outer surface from the inner tube heat transfer tube. It can be supported and fixed, or it can be slightly difficult to work, but it can also be supported and fixed from the outer jacket to the inner surface of the partition plate. Further, depending on the use conditions such as the required heat transfer load and the environmental conditions such as the allowable space shape of the installation place, a form in which a plurality of inner cylinder heat transfer tubes are accommodated in one outer cylinder jacket is possible. In that case, the partition plate can take a form supported and fixed by a support body from the upper liquid reservoir housing. The embodiments of claims 6 and 7 as described above.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “embodiments”) will be described in detail with reference to the accompanying drawings.

  1 to 3 show a first example of a falling liquid film evaporation heat exchanger according to an embodiment of the present invention. In the figure, a falling liquid film evaporation heat exchanger 10 includes an inner cylinder heat transfer tube 11, an outer cylinder jacket 12, and an upper liquid reservoir housing 13 that holds the inner cylinder heat transfer tube 11 and the outer cylinder jacket 12 together. have.

  The inner cylinder heat transfer tube 11 is a cylindrical tube having a lower surface closed and an upper surface opened. The upper liquid reservoir housing 13 formed by bonding and holding the inner tube heat transfer tube 11 and the outer tube jacket 12 is provided on the outer periphery of the upper end of the inner tube heat transfer tube 11 so as to cover the upper side of the inner tube heat transfer tube 11. Yes. Further, a partition plate 14 is provided on the outer peripheral surface of the inner tube heat transfer tube 11, that is, on the outer wall 11a of the inner tube heat transfer tube (hereinafter simply referred to as “outer wall 11a”).

  The partition plate 14 is, for example, a single elongated plate, and the elongated plate is erected so as to spiral around the outer peripheral surface (outer wall 11a) of the inner tube heat transfer tube 11, and the center is the outer tube. It is supported and fixed on the outer wall 11a so as to coincide with the concentric cylinder of the jacket 12. The partition plate 14 is in contact with the inner peripheral surface of the outer cylinder jacket 12, that is, the outer cylinder jacket inner wall 12 a (hereinafter simply referred to as “inner wall 12 a”) of the outer cylinder jacket 12, and the outer wall 11 a of the inner cylinder heat transfer tube 11. 1 and the inner wall 12a of the outer cylinder jacket 12a, a spiral high-temperature side liquid flow passage 15 schematically shown in FIG. 1B is formed. Note that the partition plate 14 and the outer wall 11a of the inner tube heat transfer tube 11 and the inner wall 12a of the outer tube jacket 12 do not necessarily need to be completely in close contact, and a gap may be provided. Further, the partition plate 14 may be provided on the inner surface of the outer cylinder jacket 12, that is, on the inner wall 12a so as to be concentric with the inner cylinder heat transfer pipe 11 without being provided on the outer wall 11a of the inner cylinder heat transfer pipe 11.

  The upper liquid reservoir housing 13 is formed in an annular container shape having an upper surface opened, and a housing portion 13a capable of storing a low-temperature liquefied gas fluid therein, and the upper surface of the housing portion 13a being closed. And a lid 13b attached to the portion 13a. The upper end portion of the inner tube heat transfer tube 11 is attached to the bottom surface of the housing portion 13a so as to penetrate the bottom surface toward the upper surface opening side and protrude to a position in the housing portion 13a. On the other hand, the lid 13b includes a low-temperature liquefied gas fluid supply port 13c connected to a low-temperature liquefied gas fluid path through which a low-temperature liquefied gas fluid, for example, liquid nitrogen (LN2) and liquefied natural gas is sent, and an inner cylinder heat transfer tube. A low-temperature vaporized gas discharge port 13d for releasing the low-temperature vaporized gas evaporated in 11a into the atmosphere is provided. And the other end side of the low temperature liquefied gas fluid supply pipe (not shown) which one end side is connected to the low temperature liquefied gas fluid which is not shown in figure is connected to the low temperature liquefied gas fluid supply port 13c.

  The outer cylinder jacket 12 is a cylindrical tube having a lower surface closed and an upper surface opened. Further, a high-temperature liquid fluid inlet 17 is provided on the outer periphery of the lower end of the outer cylinder jacket 12, and a high-temperature liquid fluid outlet 18 is provided on the outer periphery of the upper end.

  The inner diameter of the outer cylinder jacket 12 is substantially equal to the outer diameter of the partition plate 14 provided on the outer wall 11 a of the inner cylinder heat transfer tube 11, and the lower surface side of the outer cylinder jacket 12 extends from the upper surface side of the outer cylinder jacket 12. It can be inserted into the jacket 12. Further, the length (depth) of the outer cylinder jacket 12 on the inner wall 12a side is larger than the length from the lower surface of the upper liquid reservoir housing 13 provided in the inner cylinder heat transfer tube 11 to the lower surface of the inner cylinder heat transfer tube 11. Is formed. That is, when the inner tube heat transfer tube 11 is inserted into the outer tube jacket 12 until the upper end of the outer tube jacket 12 contacts the lower surface of the upper liquid reservoir housing 13, as shown in FIG. The gap α is set between the lower surface of the outer cylinder 12 and the lower surface of the outer cylinder jacket 12.

  As shown in FIG. 2, the falling liquid film evaporation heat exchanger 10 is configured so that the outer side of the inner tube heat transfer tube 11 having the upper liquid reservoir housing 13 attached to the upper portion is covered with an outer tube jacket 12. The inner tube heat transfer tube 11 is inserted into the outer tube jacket 12 until the upper end of the tube jacket 12 comes into contact with the lower surface of the upper liquid reservoir housing 13. The cylinder jackets 12 are assembled and held in a single-end supported state while being joined and held. Moreover, the opening of the housing part 13a faces upward, and the inner cylinder heat transfer tube 11 and the outer cylinder jacket 12 are installed in a state where they stand vertically.

  Further, in the falling liquid film evaporation type heat exchanger 10 assembled in this way, a spiral partition plate 14 is provided in the gap between the outer wall 11a of the inner tube heat transfer tube 11 and the inner wall 12a of the outer tube jacket 12. A defined flow path 15 for the high-temperature side liquid flow is formed, which is continuously connected from the high-temperature liquid fluid inlet port 17 at the lower end to the high-temperature liquid fluid outlet port 18 at the upper end. As shown in FIGS. 1 and 3, a slight gap is provided between the partition plate 14 and the outer cylinder jacket 12 in consideration of the assembling property and thermal distortion of the inner cylinder heat transfer tube 11 and the outer cylinder jacket 12. .

  Next, the operation of the falling film evaporation heat exchanger 10 formed in this way will be described with reference to FIG. First, on the high-temperature liquid fluid side, the high-temperature liquid fluid enters the flow path 15 of the high-temperature-side liquid flow from the high-temperature liquid-fluid inlet 17 and exits from the high-temperature liquid-fluid outlet 18 toward a high-temperature liquid-fluid storage tank (not shown). It flows while touching the outer wall 11a of the inner tube heat transfer tube 11 as a hot surface.

  On the other hand, on the low-temperature liquefied gas fluid side, the low-temperature liquefied gas fluid N (liquid nitrogen in this example) is supplied from a liquid low-temperature liquefied gas fluid storage tank (not shown) through the low-temperature liquefied gas fluid supply port 13c. Supplied in. Further, when the amount of the low temperature liquefied gas fluid N accumulated in the housing portion 13a exceeds the height position of the upper end opening edge 11c of the inner cylinder heat transfer tube 11, the low temperature liquefied gas fluid N is transferred from the housing portion 13a to the inner cylinder heat transfer tube 11. The low-temperature liquefied gas fluid N overflowing into the inside forms a liquid film and forms the inner peripheral surface of the inner cylinder heat transfer tube 11, that is, the inner wall heat transfer tube inner wall 11b (hereinafter simply referred to as “inner wall 11b”). Flow down. When the low-temperature liquefied gas fluid N overflowing from the housing portion 13 a flows down the inner wall 11 b of the inner cylinder heat transfer tube 11, the low-temperature liquefied gas fluid N is transferred to the high-temperature liquid fluid through the inner cylinder heat transfer tube 11. Heat is exchanged by heating to warm, and evaporates and vaporizes in the middle of the flow to become low-temperature vaporized gas. Further, the temperature of the high-temperature liquid fluid from the high-temperature liquid fluid outlet 18 to the high-temperature liquid fluid storage tank is finally changed by heat exchange between the heat of vaporization (latent heat of evaporation) by the low-temperature liquefied gas fluid N and the sensible heat of the high-temperature side liquid fluid. Lower. Further, the low-temperature vaporized gas vaporized in the inner tube heat transfer tube 11 is exhausted through the low-temperature vaporized gas discharge port 13d.

  Therefore, according to the falling liquid film evaporation type heat exchanger 10 according to the first embodiment, a gap α is provided between the bottom surface of the inner cylinder heat transfer tube 11 and the bottom surface of the outer cylinder jacket 12 to form a double tube. Therefore, when a thermal strain occurs between the inner tube heat transfer tube 11 and the outer tube jacket 12, the strain α can absorb the strain.

  Further, since the inner tube heat transfer tube 11 and the outer tube jacket 12 are separately formed and joined and held by the upper liquid reservoir housing, a double structure can be easily formed.

  Further, the gap is partitioned by the partition plate 14 so as to narrow the cross-sectional area of the flow path 15 of the high-temperature side liquid flow formed in the gap between the inner cylinder heat transfer tube 11 and the outer cylinder jacket 12. The flow rate of the high-temperature liquid fluid flowing through the flow path 15 of the high-temperature side liquid flow is increased. Thus, when the flow velocity of the high-temperature liquid fluid is increased, heat transfer is generally improved.

  In addition, although the flow path 15 of the high temperature side liquid flow was described as a simple spiral (spiral) flow path by the partition plate 14 formed in a spiral shape, other than this, it was formed in a staircase shape. For example, a flow path as schematically shown in FIGS. 4 to 6 may be used.

  That is, FIG. 4 shows a first modification of the flow path 15 for the high-temperature side liquid flow. The high-temperature liquid fluid entering from the high-temperature liquid fluid inlet 17 is counterclockwise in the drawing along the outer wall 11a of the inner tube heat transfer tube 11. , And then moved a predetermined distance straight up along the outer wall 11a, and then made a full left turn along the outer wall 11a again, and then moved again a predetermined distance straight up along the outer wall 11a. The process proceeds to the high temperature liquid fluid outlet 18 while repeating the above, and is formed so as to go from the high temperature liquid fluid outlet 18 to a high temperature liquid fluid storage tank (not shown).

  FIG. 5 shows a second modification of the flow path 15 for the high-temperature side liquid flow. The high-temperature liquid fluid entering from the high-temperature liquid fluid inlet 17 is approximately clockwise in the figure along the outer wall 11a of the inner tube heat transfer tube 11. The outlet of the high-temperature liquid fluid repeats the flow of making a round, then moving a predetermined distance straight up along the outer wall 11a, and making a round once clockwise around the outer wall 11a again, and then moving again a predetermined distance straight up again. The high temperature liquid fluid outlet 18 is formed so as to go to a high temperature liquid fluid storage tank (not shown).

  FIG. 6 shows a third modification of the flow path 15 for the high temperature side liquid flow. The low temperature liquid fluid entering from the low temperature liquid fluid inlet 17 is straight along the outer wall 11a of the inner tube heat transfer tube 11 to the vicinity of the upper end. And then move clockwise along the outer wall 11a for a predetermined distance, then move straight to the vicinity of the lower end, then move clockwise for a predetermined distance, and again move straight to the vicinity of the upper end. The flow is repeated, and finally, it proceeds from the vicinity of the upper end portion to the low temperature liquid fluid outlet 18 and is formed so as to go from the low temperature liquid fluid outlet 18 to a high temperature liquid fluid storage tank (not shown).

  7 to 9 show a second example of the falling liquid film evaporation heat exchanger according to the embodiment of the present invention. In the first embodiment, a structure in which one inner cylinder heat transfer tube 11 is provided in one outer cylinder jacket 12 is disclosed. However, in the second embodiment, a plurality of (one book) are provided in one outer cylinder jacket. In the embodiment, 9) inner tube heat transfer tubes are provided. The same components as those in the embodiment of FIGS. 1 to 3 are described with the same reference numerals.

  In the figure, a falling liquid film evaporation type heat exchanger 20 holds nine inner tube heat transfer tubes 21, one outer tube jacket 12, and inner tube heat transfer tube 21 and outer tube jacket 12. And an upper liquid reservoir housing 23.

  Each of the inner tube heat transfer tubes 21 is a cylindrical tube having a lower surface closed and an upper surface opened. The nine inner tube heat transfer tubes 11 are attached to the upper liquid reservoir housing 23 in such a state that they are suspended from the upper liquid reservoir housing 23 in parallel. In addition, a plurality of disc-shaped partition plates 24 (eight in this example) are arranged between the inner tube heat transfer tubes 21 and separated from each other in the vertical direction. Each partition plate 24 is formed with a plurality of (9 in this example) holes 24a that penetrate the nine inner tube heat transfer tubes 21 and a part of the high-temperature side liquid flow passage 25. A half-moon-shaped notch 24b shown in FIG. 8 is formed.

  The partition plates 24 are arranged so that the inner tube heat transfer tubes 21 are inserted into the corresponding holes 24a, are separated from each other in the vertical direction, and the notches 24b are shifted from each other by 180 degrees. Further, a plurality of (four in this example) support rods 26 suspended from the lower surface of the upper liquid reservoir housing 23 are supported and fixed in a single-end supported state suspended from the lower surface of the upper liquid reservoir housing 23. Yes.

  The partition plate 24 is disposed with a gap between the inner peripheral surface of the outer cylinder jacket 12, that is, the outer cylinder jacket inner wall 12 a of the outer cylinder jacket 12, and the inner cylinder heat transfer tube 21. The flow path 25 of the high temperature side liquid flow which flows a high temperature liquid fluid between the outer wall 21a of this and the inner wall 12a of this outer cylinder jacket 12a is defined. In the flow path 25 of the high temperature side liquid flow, the upper side communicates with the upper side at the position where the notch 24b is provided, and the position where the notch 24b is provided is shifted by 180 degrees from each other. The high-temperature liquid fluid that has flowed from the liquid-fluid inlet 17 reaches the upper high-temperature liquid-fluid outlet 18 while meandering in a zigzag manner, and flows out from the high-temperature liquid-fluid outlet 18.

  The upper liquid reservoir housing 23 is formed in an annular container shape having an upper surface opened, and a housing portion 23a capable of storing a low-temperature liquefied gas fluid therein, and the upper surface of the housing portion 23a being closed. And a lid 23b attached to the portion 23a. The upper end portion of each of the inner tube heat transfer tubes 21 is attached to the bottom surface of the housing portion 23a so as to penetrate the bottom surface toward the top opening side and protrude to a position in the housing portion 23a. Yes. On the other hand, the lid body 23b has a low-temperature liquefied gas fluid supply port 23c connected to a low-temperature liquefied gas fluid path through which a low-temperature liquefied gas fluid, for example, liquid nitrogen (LN2) or liquefied natural gas is sent, and an inner cylinder heat transfer tube. A low-temperature vaporized gas discharge port 23d for releasing the low-temperature liquefied gas evaporated in the air 21 into the atmosphere is provided. And the other end side of the low temperature liquefied gas fluid supply pipe (not shown) which one end side is connected to the low temperature liquefied gas fluid storage tank which is not illustrated is connected to the low temperature liquefied gas fluid supply port 23c.

  As in the case of the first embodiment, the outer cylinder jacket 12 is a cylindrical tube whose lower surface is closed and whose upper surface is opened. Further, a high-temperature liquid fluid inlet 17 is provided on the outer periphery of the lower end of the outer cylinder jacket 12, and a high-temperature liquid fluid outlet 18 is provided on the outer periphery of the upper end. The high temperature liquid fluid inlet 17 and the high temperature liquid fluid outlet 18 are connected to, for example, a high temperature liquid fluid pipe (not shown) for flowing a high temperature liquid fluid, for example.

  The outer cylinder jacket 12 has an inner diameter substantially equal to the outer diameter of the partition plate 24, and the inner cylinder heat transfer tube 11 integrated with the partition plate 24, the upper liquid reservoir housing 13 and the support rod 26 is connected to the outer cylinder jacket 12. It can be inserted into the outer jacket jacket 12 from the upper surface side. Also in the case of the second embodiment, the length (depth) of the outer cylinder jacket 12 on the inner wall 12a side is longer than the length from the lower surface of the upper liquid reservoir housing 23 to the lower surface of each of the inner cylinder heat transfer tubes 21. When the inner tube heat transfer tube 21 is inserted into the outer tube jacket 12 until the upper end of the outer tube jacket 12 comes into contact with the lower surface of the upper liquid reservoir housing 23, as shown in FIG. A gap α is set between the lower surface of the tube heat transfer tube 11 and the lower surface of the outer tube jacket 12.

  The falling liquid film evaporation type heat exchanger 20 is configured such that the outer cylinder jacket 12 covers the entire outside of the inner cylinder heat transfer tube 21 and the partition plate 24 with the upper liquid reservoir housing 13 attached to the upper part thereof. The inner tube heat transfer tube 21 and the partition plate 24 are inserted into the outer cylinder jacket 12 until the upper end of the upper liquid reservoir abuts the lower surface of the upper liquid reservoir housing 23, and then the upper liquid reservoir housing 23 and the outer cylinder jacket 12 are fixed. The housing portion 23a is installed in a state where the opening of the housing portion 23a faces vertically upward.

  Further, the falling liquid film type heat exchanger 20 assembled in this way is provided between the outer wall 21a of the inner tube heat transfer tube 21 and the inner wall 12a of the outer tube jacket 12 by the partition plate 24 and the notch 24b. One zigzag-shaped flow path 25 of the high-temperature side liquid flow is formed continuously from the low-temperature liquid fluid inlet 17 at the lower end to the low-temperature liquid fluid outlet 18 at the upper end.

  Next, the operation of the falling film evaporation heat exchanger 20 formed in this way will be described with reference to FIG. First, in the high-temperature refrigerant circulation path, the high-temperature liquid fluid enters the flow path 25 of the high-temperature side liquid flow from the high-temperature liquid fluid inlet 17 and exits from the high-temperature liquid fluid outlet 18 toward the high-temperature liquid fluid storage tank (not shown). It flows while touching the outer wall 21a of the inner tube heat transfer tube 21 as a hot surface.

  On the other hand, on the low-temperature liquefied gas fluid side, a low-temperature liquefied gas fluid N (liquid nitrogen in this example) from a liquid low-temperature liquefied gas fluid storage tank (not shown) passes through the low-temperature liquefied gas fluid supply port 23c and the housing portion of the upper liquid reservoir housing 23 23a is supplied. When the amount of the low-temperature liquefied gas fluid N accumulated in the housing portion 23a exceeds the height position of the upper end opening edge 21b of the inner cylinder heat transfer tube 21, the low-temperature liquefied gas fluid N is transferred from the housing portion 23a to the inner cylinder heat transfer tube 21. The low-temperature liquefied gas fluid N overflowing into the inside forms a liquid film and forms the inner peripheral surface of each inner cylinder heat transfer tube 21, that is, the inner wall heat transfer tube inner wall 21b (hereinafter simply referred to as “inner wall 21b”). Flow down. When the low-temperature liquefied gas fluid N overflowing from the housing portion 23 a flows down the inner wall 21 b of the inner cylinder heat transfer tube 21, the low-temperature liquefied gas fluid N is transferred to the high-temperature liquid fluid via the inner cylinder heat transfer tube 21. Heat is exchanged by heating to warm, and evaporates and vaporizes in the middle of the flow to become low-temperature vaporized gas. In addition, by the heat exchange between the heat of vaporization (latent heat of vaporization) by the low-temperature liquefied gas fluid N and the sensible heat of the high-temperature side liquid fluid, the temperature of the high-temperature liquid fluid finally flowing from the high-temperature liquid fluid outlet 18 to the high-temperature liquid fluid storage tank Lower. Moreover, the low temperature vaporization gas vaporized in the inner cylinder heat exchanger tube 21 is exhausted through the low temperature vaporization gas discharge port 23d.

  Therefore, even in the case of the falling liquid film evaporation type heat exchanger 20 according to the second embodiment, a gap α is provided between the bottom surface of the inner tube heat transfer tube 21 and the bottom surface of the outer tube jacket 12 to form a double tube. Therefore, when a thermal strain is generated between the inner tube heat transfer tube 21 and the outer tube jacket 12, the strain α can be absorbed.

  Further, the inner tube heat transfer tube 21 and the outer tube jacket 12 are separately formed, and the plurality of inner tube heat transfer tubes 21 are bundled together by a plurality of partition plates 24, an upper liquid reservoir housing 23 and a support rod 26, A double structure can be easily formed by inserting this inside the outer cylinder jacket 12 and joining and holding the outer cylinder jacket 12 so as to cover the outside.

  Further, the gap is partitioned by the partition plate 14 so as to narrow the cross-sectional area of the flow path 25 of the high-temperature side liquid flow formed in the gap between the inner cylinder heat transfer tube 21 and the outer cylinder jacket 12. The flow rate of the high-temperature liquid fluid flowing in the flow path 15 of the high-temperature side liquid flow is increased, and the heat transfer efficiency is generally improved.

  The present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

  The heat exchanger of the present invention can be used when it is desired to exchange heat between the sensible heat of the high temperature side liquid fluid and the latent heat of vaporization of the low temperature side liquefied gas. Heat exchangers built in the tank, heat exchangers built into the liquefied gas vaporization equipment that is gasified and supplied to consume the stored liquefied gas as fuel, etc., heat exchangers for refrigerant evaporation built into mechanical refrigerators using compressors It is applicable to.

DESCRIPTION OF SYMBOLS 10 Falling liquid film evaporation type heat exchanger 11 Inner cylinder heat exchanger tube 11a Inner cylinder heat exchanger tube outer wall 11b Inner cylinder heat exchanger tube inner wall 11c Upper end opening edge 12 Outer cylinder jacket 12a Outer cylinder jacket inner wall 13 Upper liquid reservoir housing 13a Housing part 13b Cover 13c Low-temperature liquefied gas fluid supply port 13d Low-temperature vaporized gas discharge port 14 Partition plate 15 High-temperature side liquid flow passage 16 Upper end opening 17 High-temperature liquid fluid inlet 18 High-temperature liquid fluid outlet 20 Falling liquid film evaporation heat exchanger 21 Inner cylinder Heat transfer tube 21a Inner tube heat transfer tube outer wall 23 Upper liquid reservoir housing 23a Housing part 23b Lid 23c Liquefied gas supply port 23d Vaporized gas discharge port 24 Partition plate 24a Hole 24b Notch 25 High temperature side liquid flow channel 26 Support rod N Low temperature Liquefied gas fluid α Clearance

Claims (7)

  In the falling liquid film evaporation heat exchanger that evaporates the low-temperature liquefied gas into the low-temperature vaporized gas by heat transfer heating from the high-temperature liquid fluid to the low-temperature liquefied gas fluid, the heat exchanger includes an inner cylindrical heat transfer tube whose bottom surface is closed, An outer cylinder jacket in which the inner cylinder heat transfer tube is accommodated and disposed, and an upper liquid reservoir housing in which the inner cylinder heat transfer tube and the outer cylinder jacket are joined and held vertically with a gap therebetween, The high-temperature liquid fluid is passed through a flow path formed by the gap between the outer wall of the inner cylinder heat transfer tube and the inner wall of the outer cylinder jacket, and the low-temperature liquefied gas fluid is passed from the upper liquid reservoir housing to the inner wall. Flowing down along the inner wall surface of the tube heat transfer tube, and discharging the low-temperature vaporized gas generated by heat transfer heating using the inner tube heat transfer tube as a heat transfer surface above the inner tube heat transfer tube Liquid film evaporation heat exchanger.   2. The falling liquid film evaporation according to claim 1, wherein a partition plate for narrowing a liquid flow passage cross-sectional area in the flow path is provided in the gap between the inner cylinder heat transfer tube and the outer cylinder jacket. Type heat exchanger.   3. The falling liquid film evaporation heat exchanger according to claim 2, wherein the partition plate is supported and fixed to the outer surface of the inner tube heat transfer tube.   3. The falling liquid film evaporation heat exchanger according to claim 2, wherein the partition plate is supported and fixed to the inner surface of the outer cylinder jacket.   3. The falling liquid film evaporation heat exchanger according to claim 2, wherein the partition plate is supported and fixed by a support from the upper liquid reservoir housing.   6. The falling film evaporation heat exchanger according to claim 1, 2, 3, 4 or 5, characterized in that there is only one inner tube heat transfer tube and the tube is arranged concentrically with the outer tube jacket.   6. The falling liquid film evaporation type heat exchanger according to claim 1, 2 or 5, wherein the inner tube heat transfer tube has a plurality of two or more.

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