JP2013032839A - Moving vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moving vessel capable of striking a balance between the improvement of a transportation capacity of a low-temperature liquefied gas and the improvement of the unloading workability of the low-temperature liquefied gas resulting from the improvement of a pressure evaporator.SOLUTION: In the moving vessel 1 having a tank 10 for storing the low-temperature liquefied gas and the pressure evaporator 40 having a heat transfer tube 41 into which the low-temperature liquefied gas stored in the tank 10 is introduced, the pressure evaporator 40 is forcibly fed with gas around the heat transfer tube 41. As a result, a wind speed around the heat transfer tube 41 can be accelerated, and heat transfer between the heat transfer tube 41 and air is progressed, thus reducing thermal resistance. Accordingly, a heat transfer coefficient of the pressure evaporator 40 can be increased. By this, a capacity of the pressure evaporator 40 can be improved without enlarging the pressure evaporator 40. As a result, the improvement of the transportation capacity of the low-temperature liquefied gas and the improvement of the unloading workability of the low-temperature liquefied gas resulting from the improvement of the capacity of the pressure evaporator 40 can be made compatible.

Description

  The present invention relates to a mobile container, and more particularly, to a mobile container that can achieve both an improvement in the ability to transport low-temperature liquefied gas and an improvement in workability for unloading low-temperature liquefied gas by improving the capacity of a pressurized evaporator.

  A low-temperature liquefied gas such as LNG is transported by a transport device such as a vehicle in a state where the tank (movable container) is filled. In a self-pressurization type mobile container in which a pressurized evaporator is mounted on a transport device or a mobile container, when it arrives at a transportation destination, as disclosed in Patent Document 1, the pressurized evaporator is used to lower the temperature. Unload liquefied gas. Specifically, the low-temperature liquefied gas in the tank is supplied to the pressure evaporator, and the low-pressure liquefied gas is evaporated and evaporated by the outside temperature in the pressure evaporator. The vaporized low-temperature liquefied gas (hereinafter referred to as “vaporized gas”) is refluxed to the tank to pressurize the inside of the tank, and the pressure causes the low-temperature liquefied gas to be discharged from the tank for unloading. For this reason, if the capacity of the pressurized evaporator (the ability to pressurize the inside of the tank by evaporating the low-temperature liquefied gas) can be increased, the discharge speed of the low-temperature liquefied gas from the tank can be increased. That is, the workability of unloading the low-temperature liquefied gas can be improved.

  Here, in the technique disclosed in Patent Document 1, the low-temperature liquefied gas is evaporated by the external temperature in the pressurized evaporator. The temperature difference between the low-temperature liquefied gas and the outside air temperature is one of the factors affecting the capacity of the pressurized evaporator, but is determined by the type of the low-temperature liquefied gas and the outside air temperature. Therefore, in order to improve the capacity of the pressure evaporator, it is effective to increase the heat transfer area of the pressure evaporator, which is a factor other than the temperature difference. If the pressure evaporator is enlarged, the heat transfer area can be increased, and the capacity of the pressure evaporator can be improved in proportion thereto.

JP 2007-255525 A (FIG. 4A, etc.)

  However, in the above-mentioned conventional technology, there is a limitation in the space for disposing the pressurized evaporator and the tank. Therefore, when the pressurized evaporator is increased in size, the tank must be relatively small, and the low temperature liquefied gas There was a problem that the loading capacity of the car was reduced. Moreover, since the mass of a pressure evaporator will increase if a pressurized evaporator is enlarged, the load amount of low-temperature liquefied gas will decrease by the mass, and as a result, the transport capability of low-temperature liquefied gas will decline. There was a problem. As described above, it has been difficult to achieve both improvement in the ability to transport the low-temperature liquefied gas and improvement in the unloading workability of the low-temperature liquefied gas by improving the capacity of the pressurized evaporator.

  The present invention has been made to solve the above-described problems, and can improve both the transportation capability of the low-temperature liquefied gas and the improvement in the workability of unloading the low-temperature liquefied gas by improving the capability of the pressurized evaporator. The object is to provide a mobile container.

Means for Solving the Problems and Effects of the Invention

  To achieve this object, according to the mobile container of claim 1, a pressurized evaporator having a tank for storing a low-temperature liquefied gas and a heat transfer tube into which the low-temperature liquefied gas stored in the tank is introduced. The gas is forcibly supplied around the heat transfer tube from the gas supply unit. As a result, the wind speed around the heat transfer tube can be increased, heat transfer between the heat transfer tube and gas can be promoted, and the thermal resistance can be reduced. Therefore, the heat passage rate of the pressure evaporator can be increased. Thereby, the capacity | capacitance of a pressure evaporator can be improved, without enlarging a pressure evaporator. As a result, there is an effect that it is possible to achieve both an improvement in the transport capability of the low-temperature liquefied gas and an improvement in the workability of unloading the low-temperature liquefied gas by improving the capability of the pressurized evaporator.

  Moreover, since a gas is forcibly supplied from the direction which cross | intersects a heat exchanger tube, the pressure evaporator can set independently the flow path length of a heat exchanger tube, and the flow path length of gas. Therefore, it is possible to effectively use the space while being restricted, and the pressurized evaporator provided in the tank can be made as large as possible. As a result, there is an effect that the capability of the pressure evaporator can be improved while effectively utilizing the limited space of the transportation equipment.

  According to the mobile container of the second aspect, the nitrogen gas cylinder is connected to the first connection portion, and the nitrogen gas is supplied from the gas supply portion around the heat transfer tube. Thereby, in addition to the effect of Claim 1, there exists an effect which can suppress the frost formation of a heat exchanger tube. That is, when the surface temperature of the heat transfer tube falls below 0 ° C., which is the freezing point of water, water vapor around the heat transfer tube is deprived of heat by the surface of the heat transfer tube and frosts on the heat transfer tube. When the formed frost grows and a frost layer is formed, the frost layer acts as a heat insulating layer, the heat transfer between the heat transfer tube and the air is reduced, and the thermal resistance is increased. Further, when the frost layer grows, the flow passage area around the heat transfer tube is reduced, the air volume is lowered, and the capacity of the pressurized evaporator may be greatly lowered.

  On the other hand, by forcibly supplying dry nitrogen gas from the nitrogen gas cylinder to the periphery of the heat transfer tube, the amount of water vapor that causes frost formation can be reduced. There is an effect of preventing the ability of the pressure evaporator from being lowered during the lowering operation.

  According to the mobile container according to claim 3, the pressure of the tank is introduced into the pressure guiding pipes connected to the top and bottom of the tank, respectively, and the low temperature liquefaction stored in the tank by the liquid level gauge from the pressure of the pressure guiding pipes The height of the gas level is detected.

  Here, if the low-temperature liquefied gas stored in the tank enters the pressure guiding tube due to the movement of the liquid in the tank, an error occurs in the liquid head, and the height of the liquid level cannot be measured accurately. In order to prevent this, when the low-temperature liquefied gas (drain) that has entered the pressure guiding tube is released to the atmosphere, there is a problem in safety when the low-temperature liquefied gas is a combustible gas.

  On the other hand, by connecting the nitrogen gas cylinder to the second connecting portion and supplying nitrogen gas from the pressure guiding tube toward the tank, the low-temperature liquefied gas that has entered the pressure guiding tube can be returned to the tank without being released into the atmosphere. . Since the low-temperature liquefied gas that has entered the pressure guiding tube is not released to the atmosphere, in addition to the effect of claim 1 or 2, safety can be ensured even when the low-temperature liquefied gas is a flammable gas, and the lead that causes the error of the liquid head By removing the drain in the pressure tube, there is an effect that the height of the liquid level can be accurately detected.

  According to the mobile container of the fourth aspect, the nitrogen gas is supplied from the nitrogen gas cylinder connected to the second connection portion to the communication pipe that transfers the low-temperature liquefied gas stored in the tank to the unloading facility. Therefore, after connecting the communication pipe to the piping of the unloading side facility and supplying nitrogen gas from the nitrogen gas cylinder to the communication pipe, the airtightness between the communication pipe and the piping of the unloading side facility can be confirmed, and the communication pipe In addition, air-nitrogen replacement in the piping of the unloading side facility can be performed. Thus, in addition to the effect of any one of claims 1 to 3, there is an effect that the airtightness confirmation and the air-nitrogen replacement can be performed even if the unloading facility does not have a nitrogen gas supply facility.

  According to the movable container of claim 5, since the intermittent supply device for intermittently forcibly supplying the gas from the gas supply unit to the periphery of the heat transfer tube is provided, the gas is intermittently supplied to the heat transfer tube. There is an effect which can suppress frost formation of a heat exchanger tube. That is, when the surface temperature of the heat transfer tube falls below 0 ° C., which is the freezing point of water, water vapor around the heat transfer tube is deprived of heat by the surface of the heat transfer tube and frosts on the heat transfer tube. When the formed frost grows and a frost layer is formed, the frost layer acts as a heat insulating layer, the heat transfer between the heat transfer tube and the air is reduced, and the thermal resistance is increased. Further, when the frost layer grows, the flow passage area around the heat transfer tube is reduced, the air volume is lowered, and the capacity of the pressurized evaporator may be greatly lowered.

  On the other hand, the wind speed of the gas around the heat transfer tube can be intermittently increased by the intermittent supply device that forcibly supplies the gas around the heat transfer tube. As a result, in addition to the effect of any one of claims 1 to 4, frosting of the heat transfer tube can be suppressed, and the ability of the pressurized evaporator can be prevented from being reduced during the unloading operation.

  According to the mobile container of claim 6, since the gas forcibly supplied from the gas supply unit to the pressurized evaporator is compressed air produced by a compressor that operates in conjunction with a transport device, the compressor It is possible to easily supply gas having a high wind speed to the pressurized evaporator by effectively utilizing the above. Thereby, in addition to the effect of Claim 1, there exists an effect which can improve the capability of a pressure evaporator easily.

  According to the mobile container of claim 7, since the compressed air is stored in the air tank, in addition to the effect of claim 6, the compressed air is operated without operating the compressor when the low temperature liquefied gas is unloaded. Can be supplied to the pressure evaporator.

  According to the mobile container of claim 8, since the gas forcedly supplied to the pressurized evaporator is supplied from the facility for unloading the low-temperature liquefied gas, in addition to the effect of claim 1, the compressor and air Even if a device for supplying gas such as a tank is not prepared on the movable container side, there is an effect that the ability of the pressure evaporator can be enhanced.

  According to the mobile container of claim 9, the gas forcedly supplied to the pressure evaporator is heated by the heater core or the condenser that operates in conjunction with the transportation equipment. In addition to this effect, the temperature difference between the low-temperature liquefied gas and the gas can be increased, and the ability of the pressurized evaporator can be improved. Moreover, since the temperature difference between the low-temperature liquefied gas and the gas can be increased, there is an effect that the surface temperature of the heat transfer tube can be increased and frost formation on the heat transfer tube can be prevented.

  According to the mobile container of claim 10, since the gas forcedly supplied to the pressure evaporator includes exhaust gas generated by the transportation equipment, in addition to the effect of any one of claims 1 to 9, The temperature difference between the low-temperature liquefied gas and the gas can be increased, and the capacity of the pressurized evaporator can be improved. Moreover, since the temperature difference between the low-temperature liquefied gas and the gas can be increased, there is an effect that the surface temperature of the heat transfer tube can be increased and frost formation on the heat transfer tube can be prevented.

It is a side view of the movable container in 1st Embodiment with which the apparatus for transportation was connected. It is a piping diagram which shows the piping structure of a mobile container. (A) is a top view of a pressure evaporator, (b) is a side view of a pressure evaporator, (c) is a front view of a pressure evaporator, (d) is FIG. It is sectional drawing of the heat exchanger tube in the IIId-IIId line | wire of). It is a partial schematic diagram of the movable container in 2nd Embodiment. (A) is a schematic diagram of a part of the mobile container in the third embodiment, and (b) is a schematic diagram of a part of the mobile container in the fourth embodiment. It is a piping diagram which shows the piping structure of the mobile container in 5th Embodiment.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. First, with reference to FIG. 1, the schematic structure of the mobile container 1 in 1st Embodiment with which the equipment T for transportation was connected is demonstrated. FIG. 1 is a side view of the mobile container 1 according to the first embodiment to which a transportation device T is connected. FIG. 1 illustrates a state in which a tank semi-trailer (movable container) is connected to a tractor (transport equipment).

  A mobile container (tank semi-trailer) 1 is a semi-trailer that is pulled by a transporting device (tractor) T to convey a low-temperature liquefied gas. As shown in FIG. 1, a tank 10 that contains a low-temperature liquefied gas (such as LNG). And a frame 20 that supports the tank 10 and a wheel 30 that supports the frame 20, and the frame 20 is configured to be connected to the transportation device T via a connecting device 21. The frame 20 below the tank 10 is provided with a pressurized evaporator 40 for vaporizing the low-temperature liquefied gas stored in the tank 10 by heat exchange with the outside and taking it out of the tank 10.

  Next, the piping structure of the mobile container 1 will be described with reference to FIG. FIG. 2 is a piping diagram showing the piping structure of the mobile container 1. As shown in FIG. 2, the tank 10 in which the low-temperature liquefied gas is stored includes a metal inner container 11, a metal outer container 12 that covers the entire outside thereof, and a spray disposed on the upper part of the inner container 11. And a tube 13. A space between the inner container 11 and the outer container 12 is filled with a heat insulating material such as pearlite and has a vacuum heat insulating structure. The spray tube 13 is a member for spraying a low-flowing low-temperature liquefied gas to the tank during cool-down.

  The communication port 51 is formed at one end of the communication pipe 52 and is a part used when filling the tank 10 with the low-temperature liquefied gas or sending out the low-temperature liquefied gas stored in the tank 10 to the outside. A piping of a loading facility (not shown) for supplying the cryogenic liquefied gas to the tank 10 and a piping of an unloading facility (not shown) for sending the cryogenic liquefied gas from the tank 10 are connected. A shutoff valve 53 is disposed in the communication pipe 52.

  The shut-off valve 53 is a device that can be immediately closed to shut off the flow path to prevent accidents when an abnormality occurs in the piping system or the like. The on-off valve 54 is a valve that is manually opened and closed. When the on-off valve 54 is opened, the working fluid is supplied from an air tank (not shown) to the shut-off valve 53 so that the shut-off valve 53 is opened. It is spoken. When the on-off valve 54 is closed, the shut-off valve 53 is quickly closed by the operation of a drive unit (not shown) such as a spring. The air tank (not shown) is communicated with a compressor 55 mounted on the transport equipment T (see FIG. 1). The air tank (not shown) also functions as a tank that stores compressed air, which is a working fluid of an air brake that brakes the suspension of the transport device T and the transport device T. Apart from this air tank (not shown), an air tank 56 communicating with the compressor 55 is disposed on the frame 20.

  The upper communication pipe 57 and the lower communication pipe 58 are pipes branched into two from the other end portion of the communication pipe 52. The upper communication pipe 57 is a pipe for introducing a low-temperature low-temperature liquefied gas from the upper part of the tank 10, and penetrates the outer container 12 and the inner container 11 and is disposed on the upper part of the inner container 11. It is connected to the. The upper communication pipe 57 is provided with an upper valve 59 configured so that the opening degree can be manually adjusted.

  The lower communication pipe 58 is a pipe used when introducing the low-temperature liquefied gas from the bottom of the tank 10 or sending out the low-temperature liquefied gas stored in the tank 10 to the outside, and penetrates the outer container 12. It communicates with the bottom of the inner container 11. The lower communication pipe 58 is provided with a lower valve 60 configured so that the opening degree can be manually adjusted.

  The vent pipe 61 is a pipe through which gas (boil-off gas) generated by vaporizing the low-temperature liquefied gas flows. One end of the vent pipe 61 communicates with the top of the inner container 11 and the other end is formed with a gas recovery port 62. Yes. The gas recovery port 62 is a part to which piping of a loading side facility or an unloading side facility (both not shown) is connected. The vent pipe 61 is provided with a vent valve 63 configured to adjust the opening degree.

  The pressurizing pipe 64 is a pipe for extracting the low-temperature liquefied gas from the bottom of the tank 10 and returning the evaporated low-temperature liquefied gas (vaporized gas) to the tank 10. Has been. One end of the pressurizing pipe 64 communicates with the bottom of the inner container 11, and the other end communicates with the vent pipe 61 upstream (on the tank 10 side) of the vent valve 63. A pressure valve 65 and a second pressure valve 66 are disposed downstream of the pressure evaporator 40.

  The gas supply pipe 67 is a pipe that guides gas (compressed air) to the pressurized evaporator 40, one end of which is connected to the air tank 56, and an open / close valve (not shown) that opens and closes the flow path of the gas supply pipe 67. ) And an intermittent supply device 68 are provided.

  The intermittent supply device 68 is a device that intermittently supplies fluid downstream, and in the present embodiment, is constituted by an intermittently operated valve that opens and closes the valve body intermittently. As the intermittent operation valve, for example, a known device disclosed in Japanese Patent No. 3978659 can be used. In the device (intermittently operated valve) disclosed in Japanese Patent No. 3978659, when the flow path of the gas supply pipe 67 is opened by an on-off valve (not shown) and gas is supplied from the air tank 56, the valve body is opened and closed. The operation is automatically repeated. In addition, the intermittent supply apparatus 68 is not limited to this, The apparatus comprised so that the opening / closing operation | movement of a valve body may be repeated by combining a speed controller etc. can also be used. The other end of the gas supply pipe 67 is in communication with the injection device (gas supply unit) 69, and the gas (compressed air) supplied from the air tank 56 through the gas supply pipe 67 via the intermittent supply device 68 is added. It is a device that injects toward the pressure evaporator 40.

  The unloading work performed in the unloading facility (not shown) by the mobile container 1 configured as described above will be described. The unloading operation is an operation for filling the storage tank (not shown) of the unloading side facility with the low-temperature liquefied gas filled in the tank 10. In the unloading operation, piping (not shown) of the unloading facility is connected to the communication port 51, the upper valve 59 and the vent valve 63 are closed, and the lower valve 60 is opened. When the first pressurization valve 65 and the second pressurization valve 66 are opened, the low-temperature liquefied gas in the tank 10 causes the pressurization pipe 64 to flow due to the difference in head pressure between the tank 10 and the pressurization evaporator 40 (level difference in liquid level). It is led to the pressure evaporator 40 through. When an on-off valve (not shown) disposed in the gas supply pipe 67 is opened, compressed air is supplied from the air tank 56 through the gas supply pipe 67 to the intermittent supply device 68, and the intermittent supply device 68 is compressed air. Is intermittently supplied to the injection device 69. Thereby, gas (compressed air) is forcibly supplied to the pressure evaporator 40.

  In the pressurized evaporator 40, the low-temperature liquefied gas is evaporated by heat exchange between the low-temperature liquefied gas and the gas, and the evaporated low-temperature liquefied gas (vaporized gas) passes from the vent pipe 61 to the tank 10 through the pressurized pipe 64. Refluxed. The tank 10 is pressurized by the refluxed vaporized gas, and the low-temperature liquefied gas in the tank 10 is sent to the lower communication pipe 58. The low-temperature liquefied gas sent from the tank 10 to the lower communication pipe 58 is supplied from the communication pipe 52 and the communication port 51 to piping (not shown) of the unloading side facility.

  As described above, the gas (compressed air) is forcibly supplied to the pressurized evaporator 40, so that heat transfer with the air of the pressurized evaporator 40 can be promoted and the thermal resistance of the pressurized evaporator 40 can be reduced. Therefore, the heat passage rate of the pressure evaporator 40 can be increased. Thereby, the capability of the pressure evaporator 40 can be improved without enlarging the pressure evaporator 40. As a result, it is possible to achieve both an improvement in the transporting capability of the low-temperature liquefied gas and an improvement in the unloading workability of the low-temperature liquefied gas by improving the capability of the pressurized evaporator 40.

  Here, it is possible to improve the capacity by supplying hot water or steam to the heat transfer tube 41 (see FIG. 3) of the pressurized evaporator 40. In this case, hot water or steam is supplied to the pressurized evaporator 40. There is a problem that the design of the flow path for distribution is complicated and the maintenance is also complicated. On the other hand, when the gas is forcibly supplied to the pressure evaporator 40, the existing air temperature type pressure evaporator that exchanges heat according to the outside temperature can be used as it is, and special maintenance is required. There is an advantage of not.

  Moreover, since the movable container 1 includes the intermittent supply device 68 disposed in the gas supply pipe 67, the gas can be intermittently supplied to the pressurized evaporator 40. Thereby, the wind speed of the gas around the heat exchanger tube 41 (refer FIG. 3) can be increased intermittently. As a result, since the gas staying around the heat transfer tube 41 can be replaced, frost formation on the heat transfer tube 41 can be suppressed. When the frost layer formed by frosting on the heat transfer tube 41 grows, the ability of the pressurized evaporator 40 is greatly reduced. Therefore, frost formation can be suppressed, so that the ability of the pressurized evaporator 40 is reduced during the unloading operation. It can be prevented from decreasing.

  In addition, intermittently supplying compressed air to the pressurized evaporator 40 suppresses frost formation on the heat transfer tubes 41 with a small volume of compressed air, compared with the case of supplying compressed air continuously. It is possible to prevent a decrease in the capacity of the pressure evaporator 40 during the lowering operation. Since only a small amount of compressed air is required, the consumption of compressed air stored in the air tank 56 can be suppressed. As a result, even when the capacity of the air tank 56 mounted on the mobile container 1 is small, it is possible to prevent problems such as the inability to supply compressed air to the pressurized evaporator 40 during unloading work. .

  Further, since compressed air is used, a gas having a high wind speed can be easily supplied to the pressurized evaporator 40. As a result, the capacity of the pressure evaporator 40 can be easily improved. Since the compressed air is produced by the compressor 55 that operates in conjunction with the transport equipment T, the compressor 55 of the transport equipment T can be used effectively.

  Further, since the compressed air is stored in the air tank 56, an operation of driving the engine of the transport equipment T or the like to operate the compressor 55 during the unloading operation can be made unnecessary. As a result, since the engine of the transport equipment T can be stopped during the unloading operation, it is possible to prevent ignition energy such as electric sparks from being generated. This makes it possible to handle combustible substances such as LNG and liquid hydrogen as a low-temperature liquefied gas.

  Further, since the air tank 56 is provided separately from an air tank (not shown) that stores compressed air that is a working fluid of the shut-off valve 53, the air stored in the air tank 56 is supplied to the pressurized evaporator 40. Even if it is supplied and consumed, the stability of the operation of the shutoff valve 53 can be secured.

  Next, the pressurized evaporator 40 will be described with reference to FIG. 3A is a plan view of the pressurized evaporator 40, FIG. 3B is a side view of the pressurized evaporator 40, and FIG. 3C is a front view of the pressurized evaporator 40. FIG. FIG. 3D is a cross-sectional view of the heat transfer tube 41 taken along line IIId-IIId in FIG.

  As shown in FIGS. 3 (a) to 3 (c), the pressurized evaporator 40 has a plurality of linear shapes arranged in the horizontal direction so as to be parallel to each other with a predetermined interval vertically and horizontally. A heat transfer tube (straight tube) 41, a bend tube (curved tube) 42 that connects the end portions of the heat transfer tubes 41 positioned above and below and communicates with each other so as to meander, and a heat transfer tube 41 arranged in a horizontal direction substantially orthogonal to the heat transfer tube 41 And provided with header pipes 43 and 45 through which a plurality of ends of the heat transfer pipe 41 communicate together, and connection ports 44 and 46 communicated with the header pipes 43 and 45, respectively. The connection ports 44 and 46 are connected to a pressure pipe 64 (see FIG. 2).

  In the present embodiment, the upstream side of the pressurization pipe 64 (first pressurization valve 65 side) is connected to the connection port 46, and the downstream side of the pressurization pipe 64 (second pressurization valve 66 side) is connected to the connection port 44. It is configured as follows. As a result, the low-temperature liquefied gas is guided from the connection port 46 to the pressurized evaporator 40, and is evaporated and evaporated while ascending the heat transfer tube 41 and the bend tube 42, and the vaporized gas is sent out from the connection port 44.

  As shown in FIGS. 3A and 3C, the heat transfer tube 41 is held by a plate-like support portion 47 erected in the vertical direction. A heat insulating material (not shown) that prevents heat conduction is interposed between the heat transfer tube 41 and the support portion 47. Moreover, as shown in FIG.3 (d), as for the heat exchanger tube 41, the fin 41a which expands a heat-transfer area protrudes on the surface. In the present embodiment, the fin 41 a is formed in a spiral shape around the heat transfer tube 41.

  As shown in FIG. 3, the pressurized evaporator 40 includes an extending portion 47 a that extends upward from the support portion 47. The extending portion 47 a is a member that supports both ends of the injection device 69. Accordingly, the injection device 69 is positioned above the heat transfer tube 41 and substantially parallel to the heat transfer tube 41.

  As shown in FIGS. 3A and 3C, the injection device 69 (gas supply unit) has a hole 69a formed so as to penetrate in the vertical direction. The injection device 69 is supplied with gas (compressed air) from the side by a gas supply pipe 67 (see FIG. 2) and injects it from below the hole 69a. The air flow in the injection device 69 sucks ambient air from above the hole 69a, amplifies the gas supplied from the gas supply pipe 67, and injects the gas toward the heat transfer pipe 41 from below the hole 69a. To do.

  Thus, the injection device 69 can inject a large flow rate gas into the heat transfer tube 41 by a small flow rate gas supplied from the gas supply tube 67. Since the gas supplied from the gas supply pipe 67 to the injection device 69 may be a small flow rate, the consumption of compressed air stored in the air tank 56 can be suppressed. As a result, even when the capacity of the air tank 56 mounted on the mobile container 1 is small, it is possible to prevent problems such as the inability to supply compressed air to the pressurized evaporator 40 during unloading work. .

  The pressurized evaporator 40 is forcibly supplied with gas from a direction (vertical direction) intersecting with the heat transfer tubes 41 arranged in the horizontal direction, and flows so that the low-temperature liquefied gas and the gas are orthogonal to each other. Since it is a cross flow type, the flow path length of gas (distance in the vertical direction of the heat transfer tube 41) and the flow path length of the heat transfer tube 41 can be set independently. Therefore, the space of the mobile container 1 can be used effectively, and the pressurized evaporator 40 provided in the tank 10 can be enlarged as long as the space permits. As a result, the capacity of the pressurized evaporator 40 can be improved by increasing the heat transfer area of the pressurized evaporator 40 as much as possible.

  The low-temperature liquefied gas is introduced into the heat transfer tube 41 from the lower part of the pressurized evaporator 40 and ascends the heat transfer tube 41 and the bend tube 42. On the other hand, the gas is injected downward from the injection device 69 and descends around the heat transfer tube 41. Therefore, the low-temperature liquefied gas can be heated to a temperature higher than the gas outlet temperature (the temperature of the gas when passing through the lower portion of the heat transfer tube 41). As a result, the volume of the vaporized gas can be increased, the tank 10 can be boosted efficiently, and the discharge efficiency of the low-temperature liquefied gas can be improved.

  The pressurized evaporator 40 has a low-temperature liquefied gas outlet (connection port 44) positioned upstream of the gas supplied from the injection device 69, while a low-temperature liquefied gas inlet (connection port 46) is supplied. It is located on the downstream side of the gas and is configured such that the low-temperature liquefied gas is opposed to the supplied gas. Therefore, the temperature of the low-temperature liquefied gas near the outlet (connection port 44) of the pressurized evaporator 40 can be made higher than the temperature of the low-temperature liquefied gas near the inlet (connection port 46) of the pressurized evaporator 40. As a result, even if icing or frost formation occurs in the upstream heat transfer tube 41 near the inlet (connection port 46) of the pressurized evaporator 40, the downstream side near the outlet (connection port 44) of the pressurized evaporator 40. It is possible to suppress icing or frost formation on the heat transfer tube 41. Therefore, it is possible to prevent the heat exchange efficiency from significantly decreasing due to icing or frost formation in all the heat transfer tubes 41.

  Further, as shown in FIG. 3 (d), the fin 41a is spirally formed around the heat transfer tube 41, so that the gas forcedly supplied around the heat transfer tube 41 from the top to the bottom causes a pressure drop. It can be prevented. As a result, the heat transfer between the heat transfer tube 41 and the air is prevented from deteriorating, and the capacity of the pressure evaporator 40 can be improved.

  Next, a second embodiment will be described with reference to FIG. In the first embodiment, compressed air produced by the compressor 55 is stored in the air tank 56, and the compressed air stored in the air tank 56 is forcibly supplied around the heat transfer tube 41 of the pressurized evaporator 40. did. On the other hand, in the second embodiment, the compressed air is forcibly supplied to the pressurized evaporator 140 without storing the compressed air in the air tank, and the forcibly supplied gas is heated by the heater core 82 (transport equipment T (see FIG. 1)). The case of heating in (part of) will be described.

  FIG. 4 is a schematic view of a part of the mobile container in the second embodiment. In FIG. 4, a part of the pressurized evaporator 140 of the mobile container is illustrated, and other tanks and piping are not shown. The same parts as those in the first embodiment are denoted by the same reference numerals, and the following description is omitted.

  The engine 71 of the transport equipment T (see FIG. 1) operates the compressor 75 via pulleys 72 and 74 and a belt 73. The engine 71 and the compressor 75 suck in air from the suction lines 77 and 78 through the air cleaner 76, and the compressor 75 compresses the sucked air and discharges it from the discharge line 79 to the hot air blowing device 80. The hot air blowing device 80 includes a blower 81 that introduces indoor or outdoor air of the transport equipment T into the hot air blowing device 80, and a heater core 82 that contacts the introduced air (including compressed air) and exchanges heat. Is arranged. Air (including compressed air) is heated by the heater core 82 and forcibly supplied from the hot air blowing device 80 to the pressurized evaporator 140.

  The engine 71 is provided with a water cooling jacket 83 through which cooling water flows, and the cooling water is cooled by a radiator 84. The first cooling water passage 85 is a water passage through which cooling water flows from the radiator 84 to the water cooling jacket 83, and a thermostat valve 86 and a cooling water pump 87 are provided. The second cooling water channel 88 is a water channel through which cooling water flows from the water cooling jacket 83 to the radiator 84, and communicates the water cooling jacket 83 and the radiator 84. The bypass pipe 89 is a water channel that connects the first cooling water channel 85 and the second cooling water channel 88 downstream of the cooling water pump 87.

  The first heating water channel 90 is a water channel through which cooling water flows from the water cooling jacket 83 to the heater core 82, and communicates with the water cooling jacket 83 and the heater core 82. The second heating water channel 91 is a water channel through which cooling water flows from the heater core 82 to the first cooling water channel 85, and connects the heater core 82 and the thermostat valve 86. The thermostat valve 86 is closed when the temperature of the cooling water is equal to or lower than a predetermined temperature, and communicates with the second heating water passage 91 and the first cooling water passage 85, and is opened when the temperature of the cooling water exceeds the predetermined temperature. This is a valve for communicating the radiator 84 and the water cooling jacket 83 to circulate the cooling water to the radiator 84.

  In the mobile container according to the second embodiment configured as described above, the compressor 75 is operated in conjunction with the operation of the engine 71, and compressed air is forcibly supplied from the hot air blowing device 80 to the pressurized evaporator 140. Is done. Since the temperature of the compressed air obtained by adiabatic compression by the compressor 75 rises with respect to the outside air temperature, the temperature difference between the low-temperature liquefied gas supplied to the pressurized evaporator 140 and the gas (compressed air) is increased. And the capacity of the pressure evaporator 140 can be improved. Furthermore, since the temperature difference between the low-temperature liquefied gas and the gas (compressed air) can be increased, the surface temperature of the heat transfer tube 41 (see FIG. 3) can be increased and frost formation on the heat transfer tube 41 can be prevented.

  Here, when the temperature of the cooling water is equal to or lower than the predetermined temperature, the thermostat valve 86 is closed, and the cooling water is circulated through the first heating water channel 90 and the second heating water channel 91. As a result, the cooling water heated by the water cooling jacket 83 is circulated through the heater core 82. When the temperature of the cooling water exceeds a predetermined temperature, the thermostat valve 86 is opened, and the cooling water is circulated through the first heating water channel 90 and the second heating water channel 91 while being cooled by the radiator 84. As a result, the cooling water heated by the water cooling jacket 83 is circulated through the heater core 82 and the heater core 82 is heated.

  Thus, the air introduced into the hot air blowing device 80 by the blower 81 is heated by the heater core 82 and is forcibly supplied from the hot air blowing device 80 to the pressurized evaporator 140. As a result, the temperature difference between the gas forcedly supplied to the pressurized evaporator 140 and the low-temperature liquefied gas can be increased, and the ability of the pressurized evaporator 140 can be improved. By increasing the surface temperature of the heat transfer tube 41 (see FIG. 3), frost formation on the heat transfer tube 41 can also be prevented.

  The gas (compressed air) introduced into the hot air blowing device 80 by the compressor 75 is heated by the heater core 82 and is forcibly supplied from the hot air blowing device 80 to the pressurized evaporator 140. Thereby, the temperature difference between the gas (compressed air) forcedly supplied to the pressurized evaporator 140 and the low-temperature liquefied gas can be increased, and the ability of the pressurized evaporator 140 can be improved. By increasing the surface temperature of the heat transfer tube 41 (see FIG. 3), frost formation on the heat transfer tube 41 can also be prevented.

  Next, a third embodiment and a fourth embodiment will be described with reference to FIG. In the second embodiment, the case where the gas heated by the heater core 82 (part of the heating device) is forcibly supplied to the pressurized evaporator 140 has been described. In contrast, in the third embodiment, a case will be described in which exhaust gas generated by the transportation device T (see FIG. 1) is forcibly supplied to the pressurized evaporator 240. In the fourth embodiment, a case where the gas to be forcibly supplied is heated by the condenser 101 (a part of the cooling device of the transport equipment T) will be described.

  FIG. 5A is a schematic diagram of a part of the mobile container in the third embodiment, and FIG. 5B is a schematic diagram of a part of the mobile container in the fourth embodiment. In FIG. 5, some of the pressurized evaporators 240 and 340 of the mobile container are illustrated, and other tanks and piping are not shown. The same parts as those in the first embodiment and the second embodiment are denoted by the same reference numerals, and the following description is omitted.

  First, a third embodiment will be described with reference to FIG. As shown in FIG. 5A, the engine 71 of the transportation device T (see FIG. 1) sucks air from the suction pipe 77 via the air cleaner 76 and burns the exhaust gas after exhausting the fuel into the exhaust pipe 92. To discharge from. By forcibly supplying the exhaust gas (gas) discharged from the exhaust gas pipe 92 to the pressurized evaporator 240, the temperature difference between the low-temperature liquefied gas supplied to the pressurized evaporator 240 and the gas can be increased, and the waste The capacity of the pressurized evaporator 240 can be improved by effectively using heat. Further, since the temperature difference between the low-temperature liquefied gas and the gas can be increased, the surface temperature of the heat transfer tube 41 (see FIG. 3) can be increased, and frost formation on the heat transfer tube 41 can be prevented.

  Next, a fourth embodiment will be described with reference to FIG. As shown in FIG. 5B, the cooling device 100 of the transport equipment T mainly includes a compressor 175, a condenser 101, an expansion valve 102, a cooler 103, and a blower 104.

  The compressor 175 is a device for compressing the refrigerant, and operates in conjunction with the engine 71 (see FIG. 4). The condenser 101 is a device for cooling the high-temperature and high-pressure refrigerant sent from the compressor 175, and is formed so that the refrigerant flows through the pipeline. The expansion valve 102 is a device for injecting refrigerant, and includes a nozzle and a diaphragm (both not shown). The cooler 103 is a device for cooling the air, and is formed so that the refrigerant flows through the pipeline. The blower 104 is a device for blowing air into the room of the transport device T (see FIG. 1).

  In the cooling device 100, the refrigerant is circulated according to the direction indicated by the solid line in FIG. 5B to compress and expand the refrigerant, thereby cooling the air around the cooler 103. On the other hand, since the air around the condenser 101 is heated by the high-temperature and high-pressure refrigerant, the heated air is sucked by the blower 105 and forcibly supplied to the pressure evaporator 340.

  As a result, the temperature difference between the gas forcedly supplied to the pressurized evaporator 340 and the low-temperature liquefied gas can be increased, and the capacity of the pressurized evaporator 340 can be improved by effectively using waste heat. By increasing the surface temperature of the heat transfer tube 41 (see FIG. 3), frost formation on the heat transfer tube 41 can also be prevented.

  Next, a fifth embodiment will be described with reference to FIG. In the first to fourth embodiments, the case where the atmospheric pressure is forcibly supplied to the pressurized evaporators 140, 240, and 340 has been described. On the other hand, in the fifth embodiment, a case will be described in which a nitrogen gas cylinder 423 is mounted on the mobile container 401 and nitrogen gas is forcibly supplied from the nitrogen gas cylinder 423 to the pressurized evaporator 40. In addition, about the part same as 1st Embodiment, the same code | symbol is attached | subjected and the following description is abbreviate | omitted. FIG. 6 is a piping diagram showing a piping structure of the mobile container 401 in the fifth embodiment.

  In FIG. 6, a mobile container (tank semi-trailer) 401 is a semi-trailer that carries a low-temperature liquefied gas by being pulled by a transportation device (tractor) T (see FIG. 1). The shutoff valve 402 (pressurization pipe shutoff valve) is a valve for shutting off the flow path of the pressurization pipe 64 when an abnormality occurs, and is downstream of the first pressurization valve 65 and from the pressurization evaporator 40. Arranged in the upstream pressure tube 64. The gas release valve 403 is a valve for lowering the internal pressure of the tank 10 to a specified pressure after the low temperature liquefied gas is unloaded, and the safety valve 405 is a valve for reducing the internal pressure of the tank 10 to a predetermined pressure or less. The gas release valve 403 and the safety valve 405 communicate with the ventilation pipe 61 downstream of the pressurization pipe 64, and the vaporized gas that has passed through the gas release valve 403 and the safety valve 405 is released to the atmosphere through the backfire preventer 404.

  The bypass pipe 406 communicates between the vent pipe 61 between the gas recovery port 62 and the vent valve 63 and the communication pipe 52 between the communication port 51 and the shutoff valve 53. A bypass valve 407 for opening and closing the flow path is provided. The drain valve 408 is a valve for confirming the presence or absence of drain in the vent pipe 61 and residual liquid (low-temperature liquefied gas) in the communication pipe 52, and communicates with the communication pipe 52 and the bypass pipe 406. The drain valve (third connection portion) 408 also functions as a joint to which a nitrogen gas cylinder 423 described later is detachably connected.

  The pressure guiding pipes 409 and 410 are pipes that communicate with the top and bottom of the inner tank 11 and introduce the pressure of the inner tank 11, respectively. The bypass pipe 411 is a pipe that communicates with the pressure guiding pipes 409 and 410, and a liquid level measuring base valve 412 that opens and closes the flow path of the bypass pipe 411 is provided. The liquid level gauge (differential pressure transmitter) 413 is a device for measuring the differential pressure of the pressure guiding tubes 409 and 410 and detecting the height (level) of the low temperature liquefied gas stored in the inner tank 11. Yes, the bypass pipe 411 is arranged in parallel with the liquid level measuring valve 412. Drain valves (second connection portions) 414 and 415 are valves respectively disposed at end portions of the pressure guiding tubes 409 and 410 and function as a joint to which a nitrogen gas cylinder 423 described later is detachably connected.

  The gas supply pipe 416 is a pipe that guides gas (nitrogen gas) to the pressure evaporator 40, and has one end connected to the injection device 69 and the other end connected to the first connection portion (first joint) 417. ing. The nitrogen gas pipe 418 is a pipe through which the nitrogen gas supplied from the nitrogen gas cylinder 423 flows, and one end of the nitrogen gas pipe 418 is detachably connected to the first connection portion 417. The nitrogen gas pipe 418 is connected to a drain valve 419 that discharges the drain in the nitrogen gas pipe 418 and a pressure gauge 420 that detects the pressure of the nitrogen gas pipe 418. The pressure reducing valve 421 is a device for opening and closing the flow path of the nitrogen gas pipe 418 and for reducing the pressure of the nitrogen gas supplied from the nitrogen gas cylinder 423 to the nitrogen gas pipe 418. The nitrogen gas pipe 418 is provided with a second joint 422 at the other end, and is connected to the nitrogen gas cylinder 423 through the second joint 422.

  The unloading work performed at the unloading facility (not shown) by the mobile container 401 configured as described above will be described. The unloading operation is an operation for filling the storage tank (not shown) of the unloading side facility with the low-temperature liquefied gas filled in the tank 10. In the unloading operation, first, piping (not shown) of the unloading facility is connected to the communication port 51 and the gas recovery port 62, and the upper valve 59, the lower valve 60, and the vent valve 63 are closed, and the bypass valve 407 is closed. Open the valve. Next, after removing the nitrogen gas pipe 418 and the nitrogen gas cylinder 423 connected to the first connection part 417, the nitrogen gas pipe 418 and the nitrogen gas cylinder 423 are connected to the drain valve (third connection part) 408. After closing a valve (not shown) disposed in the piping of the unloading facility near the communication port 51 and the gas recovery port 62, the pressure reducing valve 421 is opened and nitrogen gas is supplied from the drain valve 408. Thus, a leak check (confirmation of airtightness) between the communication port 51 and the gas recovery port 62 and the piping (not shown) of the unloading side facility can be performed.

  After the airtightness is confirmed, a valve (not shown) and a vent valve 63 provided in the piping of the unloading facility near the communication port 51 and the gas recovery port 62 are opened. As a result, the piping (not shown) of the unloading facility and the air in the ventilation pipe 61 are replaced with nitrogen supplied from the nitrogen gas cylinder 423, and air-nitrogen replacement in the piping is performed. Even if the unloading facility does not have a nitrogen gas supply facility, leak check (confirmation of airtightness) and air-nitrogen replacement in the pipe can be performed by the nitrogen gas cylinder 423 mounted on the mobile container 401.

  After the leak check (confirmation of airtightness) and air-nitrogen replacement in the pipe, the nitrogen gas pipe 418 and the nitrogen gas cylinder 423 connected to the drain valve (third connection part) 408 are connected to the first connection part 417. To do. Next, the upper valve 59 and the vent valve 63 are closed, and the lower valve 60 is opened. When the first pressurization valve 65 and the second pressurization valve 66 are opened, the low-temperature liquefied gas in the tank 10 causes the pressurization pipe 64 to flow due to the difference in head pressure between the tank 10 and the pressurization evaporator 40 (level difference in liquid level). It is led to the pressure evaporator 40 through. When the pressure reducing valve 421 is opened and adjusted to a predetermined pressure while looking at the pressure gauge 420, nitrogen gas is supplied from the nitrogen gas cylinder 423 to the injection device 69 through the nitrogen gas pipe 418 and the gas supply pipe 416. Since gas (nitrogen gas) is forcibly supplied to the pressurized evaporator 40, heat transfer between the heat transfer tube 41 and the gas can be promoted, and the heat passage rate of the pressurized evaporator 40 can be increased. Thereby, the capability of the pressure evaporator 40 can be improved without enlarging the pressure evaporator 40.

  Further, the humidity (water content) of the nitrogen gas supplied from the nitrogen gas cylinder 423 to the pressurized evaporator 40 is kept low (dried) compared to the humidity in the atmosphere, so the pressurized evaporator Compared with the case where air is forcibly supplied to 40, the amount of water vapor that causes frost formation can be reduced. As a result, frost formation on the heat transfer tube 41 (see FIG. 3) can be suppressed. When the frost layer formed by frosting on the heat transfer tube 41 grows, the ability of the pressurized evaporator 40 is greatly reduced. Therefore, frost formation can be suppressed, so that the ability of the pressurized evaporator 40 is reduced during the unloading operation. It can be prevented from decreasing.

  In addition, since the gas (nitrogen gas) can be forcibly supplied to the pressurized evaporator 40 using the pressure of the nitrogen gas (compressed gas) filled in the nitrogen gas cylinder 423, a large remodeling of the transportation equipment 401 is not required. The transportation device 401 can be manufactured by simply modifying the existing transportation device.

  Further, by mounting the nitrogen gas cylinder 423, the mass of the transportation equipment 401 is increased by the amount corresponding to the nitrogen gas cylinder 423, but it does not affect the loading amount of the low-temperature liquefied gas significantly. Therefore, it is possible to improve the unloading workability of the low-temperature liquefied gas by improving the capacity of the pressurized evaporator 40 while avoiding the problem that the transport capability of the low-temperature liquefied gas is reduced.

  Next, a method for eliminating an error factor in measuring the liquid level of the liquid level gauge 413 disposed in the movable container 401 will be described. The liquid level gauge 413 (differential pressure transmitter) measures the liquid level from the pressure proportional to the product of the density of the low-temperature liquefied gas (liquid) applied to the bottom surface of the inner tank 11 and the liquid level. It is a device. Since the inner tank 11 has an internal pressure due to the vaporized gas, in order to cancel the influence, the internal pressure due to the gas and the pressure of the low-temperature liquefied gas (liquid) are respectively introduced into the pressure guiding tubes 409 and 410, and the differential pressure between them is the liquid level. The height of the liquid level is detected by the total 413.

  Here, when the low-temperature liquefied gas stored in the inner tank 11 enters the pressure guiding pipes 409 and 410 due to the movement of the liquid in the tank 10, the measurement of the differential pressure becomes inaccurate and an error occurs in the liquid head. The height of the surface cannot be measured accurately. In order to prevent this, when the low-temperature liquefied gas (drain) that has entered the pressure guiding tubes 409 and 410 is released to the atmosphere, there is a problem in safety when the low-temperature liquefied gas is a combustible gas.

  In order to eliminate this, when measuring the height of the liquid level, the nitrogen gas pipe 418 and the nitrogen gas cylinder 423 are first connected to the drain valve (second connection portion) 414. Next, by opening the pressure reducing valve 421 and supplying nitrogen gas to the pressure guiding tube 409, the low-temperature liquefied gas that has entered the pressure guiding tube 409 can be returned to the inner tank 11 without being released to the atmosphere. Next, the nitrogen gas pipe 418 and the nitrogen gas cylinder 423 are connected to a drain valve (second connection part) 415, and similarly, by supplying nitrogen gas, the low-temperature liquefied gas that has entered the pressure guiding pipe 410 is not released into the atmosphere. It can be returned to the inner tank 11. Since the low-temperature liquefied gas (drain) in the pressure guiding tubes 409 and 410 can be removed without being released into the atmosphere, safety can be ensured even when the low-temperature liquefied gas is a flammable gas, and the cause of the liquid head error can be eliminated. The height of the liquid level of the low-temperature liquefied gas stored in the tank 10 can be accurately detected.

  As described above, the transportation apparatus 401 is mounted with the nitrogen gas cylinder 423 configured to be detachable from the first connection portion 417, the second connection portions 414, 415, and the third connection portion 408. As a result, the dried nitrogen gas is supplied from the nitrogen gas cylinder 423 to the pressure evaporator 40 to prevent freezing of the pressure evaporator 40 and to improve the heat exchange efficiency. In addition, by changing the connection position of the nitrogen gas cylinder 423, nonflammable nitrogen gas can be used for oxygen purge of piping, drain removal of the pressure guiding tubes 409 and 410, etc., so that even when the low temperature liquefied gas is flammable gas, it is safe Are better.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed.

  In each of the above-described embodiments, LNG has been exemplified and described as a low-temperature liquefied gas. However, the present invention is not necessarily limited thereto, and can naturally be applied to the mobile container 1, 401 that stores other low-temperature liquefied gas. It is. Examples of other low-temperature liquefied gas include liquid nitrogen, liquid oxygen, liquid argon, liquid helium, liquid hydrogen, and liquefied carbon dioxide gas.

  In each of the above-described embodiments, the mobile container 1, 401 (tank semi-trailer) connected to the transportation equipment (tractor) T has been described. However, the present invention is not necessarily limited to this and may be applied to other mobile containers. Is of course possible. Examples of other mobile containers include a tank lorry (moving a tank by a transportation device whose wheels are driven to rotate), a container, and the like.

  Although explanation is omitted in the above embodiment, the gas to be forcibly supplied to the pressurized evaporators 40, 140, 240, 340 can be supplied from the facility for unloading the low-temperature liquefied gas. The gas in this case can be used without particular limitation as long as it can be supplied from the unloading facility, and examples thereof include compressed air and nitrogen gas. By connecting the piping from the unloading facility to the injection device 69 (see FIG. 3), gas can be forcibly supplied to the pressurized evaporators 40, 140, 240, and 340.

  Thus, forced supply to the pressurized evaporators 40, 140, 240, and 340 is achieved without preparing a device for supplying gas such as the compressors 55, 75, and 175 and the air tank 56 on the movable container 1 and 401 side. The ability of the pressurized evaporators 40, 140, 240, 340 can be enhanced by supplying the gas to be supplied from the facility for unloading the low-temperature liquefied gas. Further, an operation of driving the engine of the transportation device T in order to operate the compressors 55, 75, and 175 during the unloading work can be eliminated. As a result, since the engine of the transport equipment T can be stopped during the unloading operation, it is possible to prevent ignition energy such as electric sparks from being generated. This makes it possible to handle combustible substances such as LNG and liquid hydrogen as a low-temperature liquefied gas.

  In each said embodiment, the injection apparatus 69 (gas supply part) utilizes the air current by the gas (air or nitrogen gas) supplied from the gas supply pipes 67 and 416, and sucks ambient air, and is a heat exchanger tube. Although what injected gas toward 41 was demonstrated, it is not necessarily restricted to this. For example, it is naturally possible to employ a gas supply unit (injection device) in which a large number of small holes are formed in the bottom or outer periphery of a bottomed tube. In this case, when gas is supplied to the gas supply unit, the gas is dispersed and sprayed from the small holes to the pressurized evaporators 40, 140, 240, and 340. When nitrogen gas is supplied from the nitrogen gas cylinder 423, it is difficult for the nitrogen gas to be diluted with ambient air, so that it is difficult to supply moisture in the atmosphere to the pressurized evaporators 40, 140, 240, and 340. As a result, the dried nitrogen gas can effectively prevent frost formation and icing of the heat transfer tube 41.

  Note that the case where the gas supplied from the facility for unloading the low-temperature liquefied gas or the nitrogen gas (gas) from the nitrogen gas cylinder 423 is forcibly supplied to the pressurized evaporators 40, 140, 240, 340 is described in the above embodiment. As described above, it is naturally possible to heat the gas or mix the exhaust gas with the gas. As a result, the temperature difference between the low-temperature liquefied gas and the gas can be expanded to improve the performance of the pressure evaporators 40, 140, 240, and 340, and the surface temperature of the heat transfer tube 41 can be increased above the gas dew point. It is possible to prevent frost formation on the heat pipe 41.

  In the fifth embodiment, the nitrogen gas pipe 418 communicating with the nitrogen gas cylinder 423 is removed from the first connection part 417, the second connection parts 414, 415, and the third connection part 408, and is connected to another according to the purpose. Although the case has been described, the present invention is not necessarily limited to this. It is naturally possible to connect the first connection portion 417, the second connection portions 414, 415, the third connection portion 408, and the nitrogen gas pipe 418 with a branch pipe and switch the flow path with a switching valve. Thereby, it is not necessary to remove and reconnect the nitrogen gas pipe 418, and the flow path can be switched only by operating the switching valve, so that the workability is excellent.

DESCRIPTION OF SYMBOLS 1,401 Mobile container 10 Tank 40, 140, 240, 340 Pressure evaporator 41 Heat transfer tube 55, 75, 175 Compressor 56 Air tank 68 Intermittent supply device 69 Injection device (gas supply part)
82 Heater core 101 Capacitor 408 Third connection portion 409, 410 Pressure guiding tube 413 Liquid level gauge 414, 415 Second connection portion 417 First connection portion 423 Nitrogen gas cylinder

Claims (10)

In a mobile container comprising a tank for storing a low-temperature liquefied gas and a pressure evaporator having a heat transfer tube into which the low-temperature liquefied gas stored in the tank is introduced.
A mobile container comprising a gas supply unit for forcibly supplying gas around the heat transfer tube from a direction intersecting the heat transfer tube.   The mobile container according to claim 1, further comprising a first connection part to which a nitrogen gas cylinder is connected in order to supply nitrogen gas from the gas supply part to the periphery of the heat transfer tube. A pressure guiding pipe connected to the top and bottom of the tank and introduced with the pressure of the tank;
A level gauge for detecting the height of the liquid level of the low-temperature liquefied gas stored in the tank from the pressure of the pressure guiding pipes;
3. The mobile container according to claim 1, further comprising a second connection portion to which a nitrogen gas cylinder is connected to the pressure guiding tube in order to supply nitrogen gas toward the tank. A communication pipe for transferring the low-temperature liquefied gas stored in the tank to the unloading facility;
The mobile container according to any one of claims 1 to 3, further comprising a third connection portion to which a nitrogen gas cylinder is connected in order to supply nitrogen gas to the communication pipe.   The mobile container according to any one of claims 1 to 4, further comprising an intermittent supply device that forcibly supplies gas intermittently from the gas supply unit to the periphery of the heat transfer tube.   The mobile container according to claim 1, wherein the gas forcibly supplied from the gas supply unit to the pressurized evaporator is compressed air produced by a compressor that operates in conjunction with the transportation device. .   The mobile container according to claim 6, wherein the compressed air is stored in an air tank.   The mobile container according to claim 1, wherein the gas forcibly supplied to the pressurized evaporator is supplied from a facility for unloading the low-temperature liquefied gas.   The mobile container according to any one of claims 1 to 8, wherein the gas forcibly supplied to the pressurized evaporator is heated by a heater core or a condenser that operates in conjunction with the transportation device. .   The mobile container according to any one of claims 1 to 9, wherein the gas forcibly supplied to the pressurized evaporator includes an exhaust gas generated by the transportation device.

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