JP2003214777A - Liquefied gas evaporator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquefied gas evaporator possible to be miniaturized and possible to restrict the lowering of supply stability when supplying the liquefied gas having a gaseous phase. <P>SOLUTION: In this liquefied gas evaporator, a plurality of liquefied gas flow passages 3 extended in the vertical direction are arranged with a space in the lateral direction, and each space between these plurality of liquefied gas flow passages 3 is used as a heating medium flow passage 5, and the heated heating medium flowing the heating medium passage 5 heats the liquefied gas flowing in the liquefied gas flow passage 3. The adjacent liquefied gas flow passages 3 are communicated with each other in both of upstream side ends and downstream side ends of the liquefied gas flow passages 3. A flow-in part 9, through which the liquefied gas flows into the liquefied gas flow passage 3, is provided in the downstream side end of the liquefied gas flow passage 3, and a flow-out part 11, through which the liquefied gas flows out of the liquefied gas flow passage 3, is provided in the upstream side end of the liquefied gas flow passage 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquefied gas evaporator, and more particularly to a liquefied gas evaporator formed by a plate heat exchanger.

[0002]

2. Description of the Related Art Hitherto, as a liquefied gas vaporizer, Japanese Patent Laid-Open Nos. 10-30794 and 2000-1710 have been used.
As disclosed in Japanese Patent No. 29, etc., a heat exchange pipe line through which a liquefied gas flows is arranged in a tank containing a heat medium, and the heat medium in this tank is heated to generate heat by the heat of the heat medium. The liquid phase liquefied gas in the exchange pipe is heated and evaporated to generate the gas phase liquefied gas.

By the way, in the conventional liquefied gas evaporator,
Since a tank containing the heat medium is required, the size of the device may be limited by this tank, and it is difficult to reduce the size. On the other hand, the inventors of the present application arranged a plurality of liquefied gas flow paths extending in one direction at intervals in a direction intersecting the extending direction, and provided spaces between the plurality of liquefied gas flow paths. Considering the miniaturization of the liquefied gas evaporator by forming the liquefied gas evaporator with a heat exchanger configured as a heat medium flow path, that is, a heat exchanger called a plate type or plate type heat exchanger. ing.

Here, in the liquefied gas evaporation device formed by the plate heat exchanger, the liquefied gas in the liquid phase is the consumption amount of the liquefied gas in the gas phase and the evaporation amount of the liquefied gas in the liquid phase. Flow into the liquefied gas flow path until they are balanced.
Therefore, depending on the consumption amount of the liquefied gas, among the plurality of liquefied gas flow paths, only the liquefied gas flow path provided with the inflow part for flowing the liquefied gas in the liquid phase into the liquefied gas flow path A state in which the liquefied gas is flowing in, a state in which the liquefied gas in the liquid phase is also flowing into a liquefied gas flow path other than the liquefied gas flow path in which the inflow part is provided, and the like occur.

When the inflow part of the liquefied gas flow path of the liquefied gas evaporator and the container containing the liquefied gas are connected via a liquid pipe line not provided with a pressure reducing valve, the inflow part is provided. If the liquefied gas in the liquefied gas stops flowing when the liquefied gas in the liquefied gas flows into the liquefied gas flow path, the liquefied gas in the liquefied gas flow path evaporates. The pressure inside is about to rise. Therefore, the liquefied gas in the liquid phase in the liquefied gas channel provided with the inflow portion is returned toward the container. At this time, the liquefied gas in the liquid phase returns to the connection part of the liquid pipeline with the liquefied gas flow path, that is, in the vicinity of the inflow part, and when there is no liquefied gas in the liquid phase in the liquefied gas flow path, liquefaction of the liquid phase Evaporation of gas disappears. As a result, the force for returning the liquefied gas in the liquid phase to the container is lost, and the liquefied gas in the liquid phase remains in the vicinity of the connecting portion of the liquid pipeline with the liquefied gas flow path.

On the other hand, when the liquefied gas in the liquid phase is flowing into the liquefied gas passages other than the liquefied gas passage provided with the inflow portion, the liquefied gas passage is installed when the consumption of the liquefied gas is stopped. Depending on the direction and the communication position of a plurality of liquefied gas channels, the liquefied gas in the liquid phase in the liquefied gas channels other than the liquefied gas channel provided with the inflow part may not be able to return to the container direction. is there. At this time, even if the liquid phase liquefied gas in the liquefied gas flow path provided with the inflow part is returned to the container direction and the liquid phase liquefied gas in the liquefied gas flow path provided with the inflow part disappears, By the evaporation of the liquefied gas in the liquid phase remaining in the liquefied gas channel other than the liquefied gas channel in which the section is provided,
The pressure in the liquefied gas channel tends to rise. For this reason,
The liquefied gas in the liquid phase between the container and the liquefied gas flow path provided with the inflow portion does not remain in the vicinity of the connection part of the liquid pipeline with the liquefied gas flow path, and is further returned in the container direction. However, most of the liquefied gas in the liquid pipeline may be returned to the container, and the interior of the liquid pipeline may be in a vapor phase state.

[0006] When the consumption of the liquefied gas in the gas phase is restarted when the liquid pipeline does not remain in the vicinity of the connecting portion with the liquefied gas flow path or when the inside of the liquid pipeline is in the gas phase state. ,
The liquefied gas in the liquid phase will flow into the liquefied gas evaporator after the liquefied gas in the gas phase in the pipeline is introduced. Therefore, until the liquefied gas in the liquid phase flows in, there is no evaporation of the liquefied gas in the liquid phase in the liquefied gas flow path, and the pressure of the liquefied gas in the gas phase supplied from the liquefied gas evaporator decreases. In some cases, the gas phase liquefied gas supply stability is reduced.

A first object of the present invention is to reduce the size of the liquefied gas vaporizer and to prevent the deterioration of the supply stability of liquefied gas in the gas phase.

Further, when the liquefied gas vaporizer and the container containing the liquefied gas are connected via a liquid pipe provided with the pressure reducing valve, when the consumption of the liquefied gas in the gas phase is stopped, the pressure reducing valve Becomes resistance, and it is difficult for the liquefied gas in the liquid phase in the liquefied gas channel to return toward the container. In addition, the plate heat exchanger is
The internal volume of the liquefied gas passage is smaller than that of the heat exchange pipe of the conventional liquefied gas evaporator. Therefore, depending on the amount of the liquefied gas in the liquefied gas in the liquefied gas channel, the pressure in the liquefied gas channel rises, and for example, a gas pipeline for supplying the liquefied gas in the vapor phase or liquefied gas evaporation. In some cases, a safety valve or the like provided to prevent the pressure in the liquefied gas passage of the device from rising above a preset pressure may be activated.

Here, in a state where the liquefied gas vaporizer starts to vaporize the liquefied gas in the liquid phase, that is, in the initial state of operation of the liquefied gas vaporizer, the liquefied gas and the liquefied gas flow passage of the liquefied gas vaporizer are liquefied. The temperature difference from the surface temperature of the contact surface with the gas may be a temperature difference that causes film boiling. Film boiling has a lower heat exchange efficiency than nucleate boiling and a smaller amount of liquefied gas is evaporated. For this reason, in the film boiling state in the initial operation of the liquefied gas evaporator, the amount of the liquefied gas in the liquid phase in the liquefied gas flow path is larger than that in the nucleate boiling state. In this way, if a certain amount of time elapses after the operation of the liquefied gas evaporator is started and the temperature of the inner surface of the liquefied gas flow path, that is, the heat transfer surface is lowered to the nucleate boiling state, the gas phase liquefied gas Even if the consumption of gas is stopped, the pressure in the liquefied gas flow channel rises, and it is difficult for the safety valve to operate. However, when the consumption of the liquefied gas in the vapor phase is stopped during the film boiling state, the liquid phase remaining in the liquefied gas flow channel may be changed depending on the installation direction of the liquefied gas flow channel and the communication position of the plurality of liquefied gas flow channels. The amount of the liquefied gas is larger than that in the nucleate boiling state, and the pressure in the liquefied gas passage increases, and the safety valve or the like may be activated.

On the other hand, it is conceivable to provide an accumulator in order to reduce the increase in the pressure in the liquefied gas passage when the consumption of the gas phase liquefied gas is stopped. However, when the liquefied gas vaporizer is provided with an accumulator, the size of the liquefied gas vaporizer is limited by the accumulator, and the liquefied gas vaporizer cannot be downsized.

A second object of the present invention is to reduce the size of the liquefied gas evaporator and reduce the increase in the pressure in the liquefied gas flow channel when the consumption of the vaporized liquefied gas is stopped.

[0012]

In the liquefied gas evaporation apparatus of the present invention, a plurality of liquefied gas passages extending in the vertical direction are arranged at intervals in the lateral direction, and spaces between the plurality of liquefied gas passages are arranged. Is used as a heat medium flow path, and the liquefied gas flowing through the liquefied gas flow path is heated by the heated heat medium flowing through this heat medium flow path. The inflow part, which communicates with each other at both the upper end and the lower end of the gas flow passage, and through which the liquefied gas flows into the liquefied gas flow passage, is provided at the lower end of the liquefied gas flow passage, The first problem can be solved by providing the outflow portion, through which the liquefied gas flows out from the gas passage, at the upper end of the liquefied gas passage.

When the pressure reducing valve is not provided in the liquid pipe for guiding the liquefied gas in the liquid phase stored in the container to the liquefied gas evaporator, the liquefied gas evaporator having such a structure is used. According to the liquefied gas evaporation device having such a configuration, a plurality of liquefied gas flow channels extending in the vertical direction, that is, the vertical direction are arranged at intervals in the horizontal direction, and adjacent liquefied gas flow channels are located at the upper end portion. Since it is communicated with the lower end portion, a plurality of liquefied gas flow paths are connected in parallel.

Therefore, when the consumption of the liquefied gas in the gas phase is stopped, even if the liquefied gas in the liquid phase is flowing into the liquefied gas passages other than the liquefied gas passage provided with the inflow portion, When the pressure in the liquefied gas flow channel rises due to the evaporation of the liquefied gas, the liquefied gas in the liquid phase in the liquefied gas flow channels other than the liquefied gas flow channel in which the inflow part is provided is connected to the lower end portion. Through the portion, it is returned to the liquefied gas flow path side where the inflow portion is provided. Then, the liquefied gas in the liquid phase in the liquefied gas flow path provided with the inflow part returns to the portion near the connection part of the liquid pipeline with the liquefied gas flow path, that is, the part near the inflow part, and in each liquefied gas flow path When the liquefied gas in the liquid phase disappears, the evaporation of the liquefied gas in the liquid phase disappears. Therefore, even if the liquefied gas evaporation device is formed by the plate heat exchanger, the supply stability of the liquefied gas in the gas phase does not easily deteriorate, the liquefied gas evaporation device can be downsized, and the supply of the liquefied gas in the gas phase is stable. It is possible to suppress deterioration of sex.

Further, in the liquefied gas evaporation apparatus of the present invention, a plurality of liquefied gas passages extending in the lateral direction are arranged at intervals in the vertical direction, and a space between the plurality of liquefied gas passages is used as a heat transfer medium. As a passage, the liquefied gas flowing in the liquefied gas channel is heated by the heated heat medium flowing in the heat medium channel, and the inflow part where the liquefied gas flows into the liquefied gas channel is A pipe provided with a pressure reducing valve is connected, and a plurality of liquefied gas flow paths communicate with each other at the ends of these liquefied gas flow paths and are connected in series to form a meandering flow path. However, the inflow part where the liquefied gas flows into the liquefied gas flow path and the outflow part where the liquefied gas flows out from the liquefied gas flow path are located at the ends of the liquefied gas flow paths that are not in communication with the adjacent liquefied gas flow paths. The inflow parts, which are respectively provided and through which the liquefied gas flows into the liquefied gas channel, are connected to the liquefied gas channel located on the upper side. Outflow portion liquefied gas flows out of the liquefied gas flow path, which achieves the second object by a structure that is provided in the liquefied gas channel located on the lower side.

In the case where a pressure reducing valve is provided in the liquid pipe for guiding the liquefied gas in the liquid phase contained in the container to the liquefied gas evaporator, the liquefied gas evaporator has such a structure. According to the liquefied gas evaporation device having such a configuration, a plurality of liquefied gas flow channels extending in the horizontal direction are vertically stacked to form a meandering flow channel. Furthermore, the inflow part is provided in the liquefied gas flow path located on the upper side, and the outflow part is provided in the liquefied gas flow path located in the lower side.

Therefore, the liquefied gas in the film boiling state in the liquefied gas channel flows while sliding on the lower inner surface of the liquefied gas channel from one end to the other end. Furthermore, even if the liquefied gas in the liquid phase is not evaporated in this process,
Since the flow path through which the liquefied gas flows is arranged in a meandering pattern in the vertical direction, the liquefied gas in the liquid phase flows into the liquefied gas flow path of the next stage, It flows while sliding from one end to the other. Therefore,
Since the chances of the liquefied gas coming into contact with the inner surface of the liquefied gas flow path, that is, the heat transfer surface are increased, the heat exchange efficiency is improved and the evaporation amount can be increased. Therefore, when the consumption of the liquefied gas in the gas phase is stopped, the amount of the liquefied gas in the liquid phase remaining in the liquefied gas flow channel can be reduced, so that the evaporation amount of the liquefied gas in the liquid phase can be reduced. It is possible to reduce the rise in pressure in the flow path. As a result, even if the liquefied gas evaporator is formed by the plate heat exchanger, it is possible to reduce the increase in the pressure in the liquefied gas flow channel when the consumption of the vaporized liquefied gas is stopped. It is possible to reduce the size and reduce an increase in the pressure in the liquefied gas flow channel when the consumption of the vaporized liquefied gas is stopped.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A first embodiment of a liquefied gas evaporation apparatus to which the present invention is applied will be described below with reference to FIGS. 1 and 2. FIG. 1 is a sectional view schematically showing the schematic configuration and operation of a liquefied gas evaporation device to which the present invention is applied. FIG. 2 is a block diagram showing an installation example and operation of a liquefied gas evaporation device to which the present invention is applied. In addition, in FIG. 1, a liquefied gas evaporation device formed by what is called a plate type or a plate type heat exchanger is schematically shown, but a plate type for forming the liquefied gas evaporation device of the present invention is shown. As the heat exchanger, for example, a plurality of heat transfer plates are overlapped in a state where a peripheral portion is watertightly sealed, and a heat medium flow path and a liquefied gas in which a heat medium alternately flows through a space between the heat transfer plates. Uses a plate heat exchanger with various configurations such as a liquefied gas flow path that flows through, or a structure in which multiple liquefied gas flow paths formed by hollow plates are connected and the surroundings are housed in a shell be able to.

The liquefied gas evaporation apparatus 1 of this embodiment is shown in FIG.
Liquefied gas, such as liquefied petroleum gas (LP
G), liquefied natural gas (LNG), and the like, and a liquefied gas channel 3 and a heat medium channel 5 through which a heat medium flows. The liquefied gas flow path 3 is formed by, for example, a space between two heat transfer plates, which is formed by stacking two heat transfer plates with a space therebetween at a peripheral edge portion in a sealed state. A plurality of liquefied gas flow paths 3 are arranged at intervals in the horizontal direction with the heat transfer plates arranged in the vertical direction, that is, in a state of extending in the vertical direction. The adjacent liquefied gas flow paths 3 communicate with each other at both the upper end and the lower end of the liquefied gas flow paths 3 via connecting flow paths 7a and 7b, respectively.

Further, of the liquefied gas flow paths 3 located at both ends, one liquefied gas flow path 3 is provided with an inflow portion 9 through which the liquefied gas flows, and the other liquefied gas flow path 3 is provided. The passage 3 is provided with an outflow portion 11 through which the liquefied gas flows out from the liquefied gas passage 3. The inflow part 9 is provided at the lower end of the liquefied gas flow path 3 in which the inflow part 9 is provided, and the inflow part 9 supplies the liquefied gas in the liquid phase to the liquefied gas flow path of the liquefied gas evaporator 1. A liquid pipe line 13 for leading to 3 is connected. The outflow part 11 is provided at the upper end of the liquefied gas flow path 3 in which the outflow part 11 is provided, and the outflow part 11 is passed through by the gas phase liquefied gas generated in the liquefied gas flow path 3. The flowing gas line 15 is connected. The heat medium passage 5 is formed by a space between the plurality of liquefied gas passages 3, that is, a space between the outer surfaces of the heat transfer plates facing each other forming the adjacent liquefied gas passages 3. At the upper end of the heat medium flow path 5, a heat medium supply pipeline 17 for supplying the heated heat medium to the heat medium flow path 5,
A heat medium discharge conduit 19 for discharging the heat medium from the heat medium flow path 5 is connected to the lower end of the heat medium flow path 5.

As described above, the liquefied gas evaporation device 1 is formed by the plate heat exchanger, and the heat of the heated heat medium flowing through the heat medium flow path 5 passes through the heat transfer plate to the liquefied gas flow path. The liquefied gas in the liquid phase in 3 is heated and evaporated by being transmitted to the liquefied gas in the liquid phase to generate the liquefied gas in the gas phase. In the present embodiment, the liquefied gas evaporation device 1
A pressure reducing valve is not provided in the liquid pipe line 13 connected to.

The liquid conduit 13 connected to the inflow portion 9 provided in the liquefied gas flow path 3 of the liquefied gas evaporator 1 has an end opening at the bottom of the container 21 in which the liquefied gas 20 in the liquid phase is contained. Is in a state of being inserted into the container 21. The other end of the gas pipeline 15 connected to the outflow portion 11 provided in the liquefied gas flow path 3 of the liquefied gas vaporizer 1 is connected to a device, equipment, equipment, or the like that uses liquefied gas in the gas phase as fuel. It is connected to the liquefied gas consumption unit 23. The gas pipe 15 is provided with a pressure regulator 24 for adjusting the pressure of the vaporized liquefied gas to the pressure required by the liquefied gas consuming unit 23.

The heat medium supply line 17 and the heat medium discharge line 19 are
Both are connected to the heat source device 25. In the present embodiment, a water heater having a pump 27, a burner 29, etc. built therein is used as the heat source device 25. Therefore, as the heat medium,
Water is used. The heat medium discharge pipe line 19 is connected to a burner 29 in the heat source device 25, and the heat medium supply pipe line 17 is a pump 27 provided downstream of the burner 29 with respect to the flow of the heat medium. Are linked to. By the pump 27 in the heat source device 25, the burner 2 in the heat source device 25
The heat medium heated in 9 is supplied to the heat medium flow path 5 of the liquefied gas evaporation device 1 via the heat medium supply pipe 17, and the liquefied gas in the liquefied gas flow path 3 in the liquefied gas evaporation device 1 The heat medium in the heat medium flow path 5 that has undergone heat exchange is discharged to the heat medium discharge pipeline 19, and returns to the heat source device 25 via the heat medium discharge pipeline 19.

In the present embodiment, the heat source device 25 is used as the heating medium heating means for heating the heating medium and the heating medium feeding means for feeding the heating medium. It is not necessary to use the heat source device 25 as the medium feeding means. For example, the heat medium heating means and the heat medium liquid feeding means can be provided separately, and further various configurations can be used as the heat medium heating means and the heat medium liquid feeding means. Further, the heat medium is not limited to water, and various fluids serving as the heat medium can be used.

The operation of the liquefied gas evaporator having such a structure and the features of the present invention will be described. As shown in FIG. 2, the heat source device 25 heats water serving as a heat medium to, for example, 70 ° C.
It is supplied to the heat medium flow path 5 of the liquefied gas evaporation device 1 as warm water of a certain degree. When the consumption of the liquefied gas in the liquefied gas consuming portion 23 is started in this state, the inside of the container 21 inside the container 21 is passed through the liquid pipeline 13 and the inflow portion 9 provided in the liquefied gas flow path 3 of the liquefied gas evaporator 1. The liquefied gas in the liquid phase flows into the liquefied gas channel 3 of the liquefied gas evaporator 1, and is heated and evaporated by the heat of the heated heating medium flowing through the heating medium channel 5. At this time, the inflow amount of the liquefied gas in the liquid phase into the liquefied gas flow path 3 of the liquefied gas evaporator 1 depends on the consumption amount of the liquefied gas in the gas phase and the evaporation amount of the liquefied gas in the liquefied gas in the liquefied gas flow path 3. It depends on and. That is, the liquefied gas in the liquid phase flows in until the consumption amount of the liquefied gas in the gas phase and the evaporation amount of the liquefied gas in the liquid phase in the liquefied gas channel 3 are balanced.

Therefore, as shown in FIG. 1, the liquid level of the liquefied gas 20 in the liquid phase flowing into each liquefied gas flow path 3 is the inflow amount of the liquefied gas in the liquid phase, that is, the consumption amount of the liquefied gas in the gas phase. Depends on When the consumption amount of the liquefied gas in the gas phase decreases, the inflow amount of the liquefied gas in the liquid phase decreases, so that the liquid level of the liquefied gas 20 in the liquefied gas in each liquefied gas channel 3 decreases. On the other hand, when the consumption amount of the liquefied gas in the gas phase increases, the inflow amount of the liquefied gas in the liquid phase increases, so that each liquefied gas flow path 3
The liquid level of the liquefied gas 20 in the liquid phase inside rises.

Here, when the consumption of the vaporized liquid gas is stopped, the liquid gas 20 in the liquid gas channels 3 is heated by the heat of the heat medium and evaporated, so that the flow of each liquid gas is increased. Suppose the pressure in the path 3 tries to rise. This allows
The liquefied gas 20 in the liquid phase in the liquefied gas channel 3 other than the liquefied gas channel 3 provided with the inflow portion 9 is
It is returned to the direction of the liquefied gas flow path 3 in which the inflow part 9 is provided via the connection flow path 7b provided in the lower end part. That is, the liquefied gas 20 in the liquid phase in the liquefied gas channel 3 other than the liquefied gas channel 3 in which the inflow portion 9 is provided flows in the direction of the arrow shown by the broken line in FIG. Further, the liquid phase liquefied gas 20 in the liquefied gas flow path 3 provided with the inflow portion 9 is returned to the liquid pipe line 13 direction, that is, the container 21 direction, and as shown in FIG.
Flows in the direction of the arrow indicated by the broken line in FIG.

The liquid phase liquefied gas 20 in the liquefied gas channel 3 other than the liquefied gas channel 3 provided with the inflow portion 9 is returned to the liquefied gas channel 3 provided with the inflow portion 9, Liquid phase liquefied gas 2 in liquefied gas channel 3 provided with inflow part 9
0 returns to a portion near the connecting portion of the liquid pipeline 13 with the liquefied gas flow passage 3, that is, a portion near the inflow portion 9, and when the liquefied gas 20 in the liquid phase disappears in each liquefied gas flow passage 3, the liquid phase is liquefied. Gas 2
Evaporation of 0 disappears. When the evaporation of the liquefied gas 20 in the liquid phase is stopped, the pressure in the liquefied gas flow path 3 does not rise, so that the force for returning the liquefied gas 20 in the liquid phase in the liquid conduit 13 to the container 21 direction does not occur, Liquid phase liquefied gas 2 in the liquid conduit 13
0 remains in the vicinity of the connecting portion of the liquid pipe 13 with the liquefied gas flow path 3.

As described above, in the liquefied gas vaporizer 1 of the present embodiment, the liquefied gas flow path 3 is placed vertically, and the plurality of liquefied gas flow paths 3 are connected to each other at both the upper end and the lower end. And a plurality of liquefied gas flow paths 3 are connected in parallel. Therefore, when the consumption of the gas phase liquefied gas is stopped, even if the liquid phase liquefied gas 20 is flowing into the liquefied gas channel 3 other than the liquefied gas channel 3 provided with the inflow portion 9,
When the pressure in the liquefied gas passage 3 is attempted to rise due to the evaporation of the liquefied gas 20 in the liquid phase, the liquefied gas in the liquefied gas in the liquefied gas passages 3 other than the liquefied gas passage 3 in which the inflow portion 9 is provided. 20 is returned to the liquefied gas flow path 3 side in which the inflow part 9 is provided via the connection flow path 7b provided in the lower end part. Then, the liquefied gas 20 in the liquid phase in the liquefied gas flow path 3 provided with the inflow portion 9 returns to the vicinity of the connecting portion of the liquid pipeline 13 with the liquefied gas flow path 3, and the liquefied gas flow path 3 is liquefied. When the liquefied gas 20 in the phase disappears, the liquefied gas in the liquid phase does not evaporate.

Therefore, the liquid phase liquefied gas 20 in the liquid conduit 13 remains in the vicinity of the connection portion of the liquid conduit 13 with the liquefied gas flow path 3, and the liquid phase liquefied gas 20 is Thirteen
When the consumption of the vaporized liquefied gas is resumed without further returning from the vicinity of the connection portion with the liquefied gas flow path 3 in the direction of the container 21 or the inside of the liquid pipeline 13 being in the vapor phase state. The pressure drop of the liquefied gas in the phase can be suppressed. That is, the liquefied gas evaporator 1 of the present embodiment is formed of a plate heat exchanger, but the supply stability of the gas phase liquefied gas is less likely to decrease, and the liquefied gas evaporator can be downsized and It is possible to suppress a decrease in the supply stability of the liquefied gas in the phase.

Further, depending on the installation direction of the liquefied gas flow path or the communication position of the plurality of liquefied gas flow paths, it is difficult to drain the drain accumulated in the liquefied gas flow path 3, and if the drain cannot be discharged, the liquefied gas flow The drain accumulated in the passage hinders the flow of the gas phase liquefied gas, and in some cases,
The supply of the vapor phase liquefied gas may be stopped. But,
In the liquefied gas vaporization device 1 of the present embodiment, since the lower end of each liquefied gas flow path 3 is communicated with the connection flow path 7b, the drain accumulated in each liquefied gas flow path 3 is easily discharged. be able to.

In addition, generally in the plate type heat exchanger,
It is difficult to increase the passage area of the flow path and reduce pressure loss. However, in the liquefied gas vaporization device 1 of the present embodiment, since the liquefied gas flow paths 3 are connected in parallel, the passage area can be increased, and thus the pressure loss can be reduced.

(Second Embodiment) A second embodiment of the liquefied gas evaporation apparatus to which the present invention is applied will be described below with reference to FIG.
And FIG. 4 will be described. FIG. 3 is a cross-sectional view schematically showing the schematic configuration and operation of a liquefied gas evaporation device to which the present invention is applied. FIG. 4 is a block diagram showing an installation example and operation of a liquefied gas evaporation device to which the present invention is applied. In the present embodiment, the same components and operations as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. The configuration and the characteristic portion different from those in the first embodiment will be described. Further, although FIG. 3 schematically shows a liquefied gas evaporation device formed by what is called a plate type or plate type heat exchanger, a plate type for forming the liquefied gas evaporation device of the present invention is shown. As in the first embodiment, plate heat exchangers having various configurations can be used as the heat exchanger.

The liquefied gas evaporation device of this embodiment is different from that of the first embodiment in that it is connected to a liquid pipe line provided with a pressure reducing valve, and the liquefied gas flow path is set horizontally. This is because a plurality of liquefied gas flow paths were connected in series.
That is, the liquefied gas evaporation device 31 of the present embodiment is shown in FIG.
As shown in FIG. 5, the liquefied gas flow paths 3 are arranged in the vertical direction, that is, in the vertical direction at intervals with the heat transfer plates arranged in the horizontal direction, that is, in the state of extending in the horizontal direction. In the liquefied gas flow passage 3 located at the upper end of the plurality of liquefied gas flow passages 3, an inflow portion 9 is formed on the upper surface of one end portion and a connecting flow is formed in the other end portion in a direction opposite to the inflow portion 9. A path 7 is provided. On the other hand, in the liquefied gas channel 3 located at the lower end, the outflow portion 11 is provided on the lower surface of one end portion, and the connection passage 7 is provided at the other end portion in the direction opposite to the outflow portion 11.

Of the plurality of liquefied gas flow paths 3, the end portions on both sides of the liquefied gas flow path 3 located in the middle are vertically adjacent to each other via connection flow paths 7 provided in mutually opposite directions. It is connected to the corresponding end of the liquefied gas channel 3. That is, the connection flow paths 7 are alternately provided at both ends of the plurality of liquefied gas flow paths 3, and the plurality of liquefied gas flow paths 3 are connected in series to form a meandering flow path. is doing. In addition,
A pressure reducing valve 33 is provided in the liquid conduit 13 connected to the inflow portion 9. In addition, at one side end of the heat medium channel 5,
The heat medium supply pipe 17 for supplying the heat medium heated to the lower side portion to the heat medium flow passage 5 is provided at the other side end portion of the heat medium flow passage 5 from the heat medium flow passage 5 to the upper side portion. A heat medium discharge conduit 19 for discharging the medium is connected.

As described above, the liquefied gas evaporator 31 of the present embodiment is also formed by the plate heat exchanger as in the first embodiment, and the heated heat medium flowing through the heat medium passage 5 is The heat is transferred to the liquefied gas in the liquefied gas in the liquefied gas flow path 3 through the heat transfer plate to heat and evaporate the liquefied gas in the liquid phase to generate the liquefied gas in the gas phase.

As shown in FIG. 4, the pressure reducing valve 33 provided in the liquid conduit 13 of the present embodiment is provided with a pressure detecting pipe 35 for transmitting the pressure in the gas conduit 15 to the pressure reducing valve 33. . Then, the pressure reducing valve 33 causes the flow rate of the liquid phase liquefied gas 20 introduced from the container 21 such that the pressure in the gas pipeline 15 detected through the pressure detection pipe 35 becomes a preset pressure. Is adjusted to reduce the pressure, and the liquefied gas in a gas-liquid mixed state is sent to the liquefied gas evaporator 31. For example,
If a liquefied gas in a liquid phase having a pressure equal to or higher than a predetermined pressure is directly introduced into the liquefied gas evaporator by legal regulation, high pressure gas is produced. Therefore, in such a case, a pressure reducing valve is used. If the liquefied gas depressurized below the pressure determined by the pressure reducing valve is introduced into the liquefied gas evaporation device, it becomes a consumable evaporator, and the production permission of the high pressure gas becomes unnecessary.

The operation of the liquefied gas evaporator having such a configuration and the features of the present invention will be described. As shown in FIG. 4, the heat source device 25 heats water serving as a heat medium to, for example, 70 ° C.
It is supplied to the heat medium flow path 5 of the liquefied gas evaporation device 1 as warm water of a certain degree. When the consumption of the liquefied gas in the liquefied gas consuming portion 23 is started in this state, the inside of the container 21 inside the container 21 is passed through the liquid pipeline 13 and the inflow portion 9 provided in the liquefied gas flow path 3 of the liquefied gas evaporator 1. The liquefied gas in the liquid phase flows into the liquefied gas channel 3 of the liquefied gas evaporator 1, and is heated and evaporated by the heat of the heated heating medium flowing through the heating medium channel 5. At this time, the liquid-phase liquefied gas 20 flowing through the liquid conduit 13 is depressurized by the decompression valve 33 to, for example, about 0.2 MPa, and then flows into the liquefied gas flow path 3 from the inflow portion 9. The liquid phase liquefied gas 20 decompressed by the decompression valve 33 is adiabatically expanded and its temperature is lowered, and becomes a liquefied gas in a gas-liquid mixed state at a temperature of, for example, about −15 ° C.

In this way, in the state where the liquefied gas vaporizer 31 has started to vaporize the liquefied gas in the liquid phase, that is, in the initial state of operation of the liquefied gas vaporizer 31, the liquefied gas and the liquefied gas vaporizer 31 The temperature difference from the surface temperature of the contact surface of the flow path 3 with the liquefied gas is a temperature difference that causes film boiling, for example, the temperature difference ΔT = 85 ° C. In the present embodiment, FIG.
As shown in FIG. 3, since the liquefied gas flow path 3 extends in the lateral direction, the liquefied gas in a gas-liquid mixed state, which is in the film boiling state, flows on the inner surface of the lower part of the liquefied gas flow path 3. It slides from the end on the side where the inflow portion 9 is provided toward the end on the side where the connecting flow path 7 is provided. Furthermore, a plurality of liquefied gas flow paths 3
When the liquefied gas is still in a gas-liquid mixed state, which has been slid to the end portion on the side where the connection flow path 7 is provided, since there is still a state in which they are vertically stacked and connected in a meandering series. In this case, the liquefied gas in the gas-liquid mixed state falls from the connecting flow path 7 to the liquefied gas flow path 3 of the next stage, and as described above, from one end to the other end of the liquefied gas flow path 3. Liquid gas flow path 3
Slide in contact with the inner surface of.

Therefore, it is possible to increase the chances of contact between the liquefied gas in the gas-liquid mixed state in the film boiling state and the inner surface of the liquefied gas flow path 3 and improve the heat exchange efficiency. Each liquefied gas flow path 3 when the consumption of the liquefied gas in the gas phase is stopped in the film boiling state at the beginning of operation
The amount of liquefied gas in the liquid phase remaining inside can be reduced. As a result, the evaporation amount of the liquefied gas in the liquid phase after the consumption of the liquefied gas in the gas phase is stopped is reduced, so that the rise in the pressure in the liquefied gas flow path 3 is reduced. In addition, the liquefied gas evaporator 31
In the initial stage of the operation, the consumption of the liquefied gas in the gas phase did not stop when the film was in a boiling state, the liquefied gas continued to flow into the liquefied gas channel and vaporized, and the temperature of the inner surface of the liquefied gas channel decreased. When you come
The boiling state of the liquefied gas is nucleate boiling having higher heat exchange efficiency than film boiling.

As described above, in the liquefied gas vaporizer 31 of the present embodiment, the liquefied gas flow path 3 is placed horizontally and a plurality of liquefied gas flow paths 3 are connected in a meandering manner in series. Therefore, the liquefied gas in the film boiling state in the initial stage of the operation of the liquefied gas vaporizer 31 moves while sliding in the liquefied gas flow path 3 and is in the film boiling state that could not be evaporated in the liquefied gas flow path 3 of one stage. The liquefied gas flows into the liquefied gas channel 3 in the next stage. Therefore, the chances of contact between the liquefied gas in the film boiling state and the inner surface of the liquefied gas flow path 3, that is, the heat transfer surface are increased, so that the heat exchange efficiency can be improved. By improving the heat exchange efficiency, it is possible to reduce the amount of the liquid phase liquefied gas in each liquefied gas channel 3 when the consumption of the gas phase liquefied gas is stopped in the film boiling state. Since the evaporation amount of the liquefied gas is reduced, the increase in the pressure in the liquefied gas flow path 3 is reduced. Therefore, the liquefied gas evaporation device 3 of the present embodiment
Although No. 1 is formed of a plate heat exchanger, it is possible to reduce an increase in the pressure in the liquefied gas flow channel when the consumption of the gas phase liquefied gas is stopped. That is, the liquefied gas evaporation device can be downsized, and the rise in the pressure in the liquefied gas flow path when the consumption of the vaporized liquefied gas is stopped can be reduced.

Furthermore, since the chances of contact between the liquefied gas and the heat transfer surface of the liquefied gas channel are increased and the heat exchange efficiency is improved,
The liquefied gas evaporator can be further downsized.

In addition, since the drain generated in the liquefied gas flow path 3 flows down to the liquefied gas flow path 3 in the lowermost stage, a drain removing means or the like may be provided in the outflow portion 11 of the liquefied gas flow path 3. , The drain can be easily discharged. Therefore, the drain accumulated in the liquefied gas flow passage prevents the flow of the liquefied gas in the gas phase, and in some cases, the supply of the liquefied gas in the gas phase does not stop.

[0044]

According to the present invention, the liquefied gas vaporizer can be downsized and the deterioration of the supply stability of the liquefied gas in the vapor phase can be suppressed.

Further, according to the present invention, the liquefied gas evaporation device can be downsized, and the rise in the pressure in the liquefied gas flow channel when the consumption of the vaporized liquefied gas is stopped can be reduced.

[Brief description of drawings]

FIG. 1 is a first liquefied gas evaporator according to the present invention.
3 is a cross-sectional view schematically showing the schematic configuration and operation of the embodiment of FIG.

FIG. 2 is a block diagram showing an installation example and operation of the liquefied gas evaporation device of the first embodiment to which the present invention is applied.

FIG. 3 is a second liquefied gas evaporation device to which the present invention is applied.
3 is a cross-sectional view schematically showing the schematic configuration and operation of the embodiment of FIG.

FIG. 4 is a block diagram showing an installation example and operation of a liquefied gas evaporation device according to a second embodiment to which the present invention is applied.

[Explanation of symbols]

1 Liquefied gas evaporator 3 Liquefied gas flow path 5 Heat medium flow path 7 connection channels 9 Inflow section 11 Outflow part

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Claims (2)

[Claims] 1. A plurality of liquefied gas passages extending in the longitudinal direction are arranged at intervals in the lateral direction, and a space between the plurality of liquefied gas passages is used as a heat medium passage, and the heat medium passage is It is a liquefied gas vaporization device formed by heating a liquefied gas flowing in the liquefied gas channel with a heated heating medium flowing through, and the adjacent liquefied gas channels are the upper end of the liquefied gas channel. Part and the lower end part are in communication with each other, the inflow part where the liquefied gas flows into the liquefied gas flow path is provided at the lower end part of the liquefied gas flow path, and from the liquefied gas flow path. The liquefied gas evaporation device is characterized in that an outflow portion through which the liquefied gas flows out is provided at an upper end portion of the liquefied gas flow path. 2. A plurality of liquefied gas passages extending in the lateral direction are arranged at intervals in the vertical direction, and a space between the plurality of liquefied gas passages is used as a heat medium passage, and the heat medium passage is A liquid provided with a pressure reducing valve at the inflow portion where the liquefied gas flowing in the liquefied gas flow channel is heated by the heated heating medium flowing therethrough, and the liquefied gas flows into the liquefied gas flow channel. A liquefied gas evaporation device in which pipes through which liquefied gas of a phase flows is connected, wherein the plurality of liquefied gas flow paths communicate with each other at the end of each liquefied gas flow path and are connected in series to meander. -Shaped flow paths are formed, and an inflow part where the liquefied gas flows into the liquefied gas flow path and an outflow part where the liquefied gas flows out from the liquefied gas flow path are adjacent to the liquefied gas flow paths. The inflow portion, which is respectively provided at the end portion on the side not communicating with, and through which the liquefied gas flows into the liquefied gas channel, A liquefied gas evaporation device, characterized in that the liquefied gas passage located on the side of the liquefied gas passage has an outflow portion through which liquefied gas flows out of the liquefied gas passage. .