JP2005090554A - System for transferring and filling liquefied gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system capable of stably transferring and filling LP gas (liquid), while restricting equipment cost as much as possible, and facilitating maintenance thereof. <P>SOLUTION: This system for transferring and filling liquefied gas is formed of a reservoir device 1 for storing LP gas in the liquid condition and capable of feeding the LP gas liquid with head pressure or/and dead weight thereof, a LP gas heater 2 for receiving the predetermined quantity of the LP gas liquid from the reservoir device and, thereafter, capable of feeding the LP gas liquid by pressurizing a gas phase part in the sealed condition, a heat source 5 for heating the LP gas liquid inside the LP gas heater to generate the steam pressure to pressurize the gas phase part of the LP gas heater, and a transferring and filling device 3, to which the LP gas liquid is fed from the LP gas heater. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a series of systems for transferring and filling liquefied gas liquid stored in a bulk storage tank to an LP gas vehicle using liquefied gas as fuel. A series of systems for transferring and filling the LP gas liquid from the tank truck to the bulk storage tank is also disclosed.

  Currently, the spread of LP gas vehicles is desired for the purpose of saving oil resources and preserving the global environment. It is a well-known fact that, in implementing this technology, it is important not only to develop an LP gas vehicle but also to establish a fuel supply method, that is, an LP gas stand system technology.

  Therefore, a conventional example of the system will be described. There are roughly two LP gas transfer and filling systems. First, the first is a method of transferring LP gas in a bulk storage tank in a liquid state (LP gas liquid) dispenser using a liquid feed pump using electricity as a power source. Still, the second is equipped with a bulk storage tank of propane vaporized gas, nitrogen or natural gas (CNG) (hereinafter simply referred to as propane vaporized gas, etc.) separately from the bulk storage tank of butane gas (liquid) as fuel. The bulk tank of butane gas (liquid) is pressurized by the vaporization pressure of propane vaporized gas and the like, and the structure of transferring the butane gas (liquid) to the dispenser is adopted.

  Next, problems of the conventional system will be described. First, in the first system, cavitation will occur if NPSH (Net Positive Suction Head / suction head) between the storage tank and the liquid feed pump is not secured, and transfer and filling cannot be performed smoothly. There was a connected problem. In order to avoid this problem, the installation height of the liquefied gas storage tank needs to be considerably increased. However, if this is the case, it will be necessary to take strong measures against earthquakes. Occurs. In addition, an electrically driven liquid feed pump requires a high-voltage power supply of 200 V or more, and the pump falls under the High-Pressure Gas Safety Law, and corresponds to a treatment facility. It is no exaggeration to say that various legal obligations, such as resident residence, have caused the spread of the LP gas stand system.

  On the other hand, in the second system, a bulk storage tank of propane vaporized gas or the like for obtaining a transfer pressure is required separately from the butane bulk storage tank that serves as fuel, and at least two storage tanks are required. For this reason, it is necessary to secure a large installation area for the installation of the system. In particular, in this system, propane vaporized gas or the like may enter the butane side, leading to a reduction in the combustion rate. Therefore, in order to keep the butane component constant, a supplemental butane gas (liquid) storage tank may be added. In this case, the problem of expansion of the installation area and a rise in equipment costs is further promoted. In addition, since this system employs a method of vaporizing propane, etc., depending on the outside temperature, the vaporization pressure of propane, etc., and the amount of butane transferred, which is easily affected by changes in the outside temperature, is stable. There is also a problem that it is difficult to do.

  The present invention has been made to solve the above-described problems of the prior art, and the object of the present invention is to suppress the equipment cost as much as possible, facilitate the safety management, and stably transfer the LP gas (liquid). A system that can be filled is disclosed.

  In order to achieve the above-described object, the present invention stores a LP gas in a liquid state and can send out the LP gas liquid by a head pressure or / and its own weight, and a predetermined amount of LP gas liquid from the tank device. Then, the gas phase is pressurized in a sealed state, and the LP gas warmer capable of delivering the LP gas liquid is heated, and the LP gas liquid in the LP gas warmer is heated to reduce the vapor pressure. The system was composed of a heat source that pressurizes the gas phase portion of the LP gas warmer by generating it, and a transfer filling destination means for sending the LP gas liquid from the LP gas warmer. In claim 2, hot water heated by a heater is used as a heat source.

  According to a third aspect of the present invention, a liquid delivery valve is provided on the transfer gas filling means side of the LP gas heater, and the liquid delivery valve is configured to supply the liquid delivery pressure to the transfer filling means, the vapor pressure of the storage tank device, and the heater The means for controlling the opening and closing by the differential pressure with the pressure in the LP gas heater heated by the pressure was used. Specifically, for example, the liquid delivery valve is achieved by means of opening / closing control by a differential pressure sensor that electrically compares the gas phase pressure of the storage tank device and the set pressure in the LP gas heater by the heater. .

  On the other hand, according to the fourth aspect of the present invention, there is used a means in which a liquid delivery valve is provided on the transfer gas filling destination means side of the LP gas heater, and the liquid delivery valve is constituted by an air valve. Further, according to a fifth aspect of the present invention, means is used in which the liquid delivery valve is constituted by an electromagnetic valve.

  Further, in claim 6, two LPG gas heaters are provided in parallel, each heater is provided with a liquid level gauge, the gas phase portions of both heaters are connected by a delivery valve, and the delivery valve Is controlled by the LP gas liquid lowering signal of one heater detected by the liquid level gauge, and the gas phase pressure of one heater is applied to the LP gas liquid delivery pressure of the other heater. I used the means.

  Further, in claim 7, the storage device is a bulk storage tank of LP gas liquid, and the transfer and filling destination means is an LP gas vehicle via a dispenser, whereas in claim 8, the storage device is a tank tank of LP gas liquid. It was a car, and the transfer and filling destination was a bulk storage tank of LP gas liquid. Further, in the means of claim 9, the heater is a tank lorry radiator.

  As described above, according to the present invention, since no liquid feed pump is used, cavitation does not occur and no power source is required, so that the equipment cost for system construction can be greatly reduced. . In addition, there is no legal obligation such as resident security personnel due to the structure, which contributes to the spread of this kind of system. In addition, since a bulk storage tank for propane is not required, the storage tank only needs to be an LP gas liquid, and the equipment cost can be reduced as the installation area is reduced. Further, since propane is not required at all, impurities are not mixed in butane which is an LP gas liquid fuel, and an inadvertent reduction in the combustion rate is avoided. Furthermore, since the forced heating means by the heater is provided, the LP gas liquid can be stably supplied without being influenced by the outside air temperature.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a circuit diagram of a liquefied gas transfer and filling system according to a first embodiment of the present invention, which is applied to an auto gas stand that supplies LP gas (liquid) to an LP gas vehicle. In the figure, 1 is a bulk storage tank that stores LP gas (liquid), 2 is LP gas that receives LP gas from the bulk storage tank 1 in a liquid state, pressurizes it, and supplies the LP gas (liquid) to a later-described dispenser 3. The warmer 3 fills the LP gas vehicle with LP gas (liquid) through a nozzle or the like, and is an LP gas (liquid) dispenser having substantially the same function as a dispenser in a conventional gas station. Reference numeral 4 denotes a heating-only heat source unit, which is configured to generate warm water and circulate the warm water to the heater 5. The heater 5 pressurizes the gas phase portion in the LP gas heater 2 by heating the LP gas (liquid) in the heat exchanger 5 ′ that communicates with the LP gas heater 2, and thereby the LP gas heater. LP gas (liquid) is fed from 2 to the dispenser 3.

  When the connection of each part is explained in detail, in the case of this embodiment, the bulk storage tank 1 stores about 1 t of LP gas (liquid) in the embodiment, and an LP gas (liquid) outlet 1a is provided at the bottom thereof. The LP gas heater 2 is connected via a shutoff valve 1b and a liquid receiving automatic valve 1c. Similarly, the upper gas phase portion of the bulk storage tank 1 is also connected to the LP gas heater 2 through the shutoff valve 1d and the vapor return automatic valve 1e. Here, the bulk storage tank 1 has a higher installation position than the LP gas heater 2, and the LP gas (liquid) in the bulk storage tank 1 is sent to the LP gas heater 2 by the head pressure and its own weight. .

  On the other hand, a liquid delivery valve 6 a operated by an electric differential pressure sensor 6 is provided in the path from the LP gas heater 2 to the dispenser 3, and the LP gas heater is provided by the liquid phase line 7. The liquid phase part 2 and the dispenser 3 are connected. The sensor 6 is configured to supply liquid pressure of the LP gas warmer 2 heated with hot water and a pressure in the gas phase portion of the LP gas warmer 2 generated by hot water heating to the head pressure of the bulk storage tank 1 (for example, 0. 3MP) is electrically compared, and when the liquid delivery pressure becomes equal to or higher than the total pressure, the liquid delivery valve 6a is opened, and the LP gas (from the LP gas heater 2 to the dispenser 3) Liquid) is configured to allow delivery. The line in the direction opposite to the dispenser 3 in the liquid phase line 7 is joined via the relief valve 8 with the connection line of the bulk storage tank 1 and the LP gas heater 2 where the liquid receiving automatic valve 1c described above exists. .

  In addition, 9 is a hot water automatic valve for circulating the hot water of the heating-only heat source 4 to the LP gas heater 2 side. Moreover, in this apparatus, 75-80 degreeC warm water is generated.

  Further, the liquid reception automatic valve 1c, the vapor return automatic valve 1e, and the hot water automatic valve 9 described above input the pressure generated by the pressure (control pressure) generator 10 such as an air compressor as the control pressure, and operate the on-off valve. is there.

  The operation of the auto gas stand type liquefied gas transfer / filling system having the above configuration will be described. First, the LP gas warmer 2 receives the liquefied gas (liquid) from the bulk storage tank 1, and the shut-off valve 1b of the bulk storage tank 1 is opened. In this state, by simultaneously opening the liquid reception automatic valve 1c and the vapor return automatic valve 1e on the LP gas heater 2 side, the LP gas (liquid) in the bulk storage tank 1 is heated by the head pressure and its own weight. Transferred to vessel 2.

  Then, the liquid phase level of the LP gas heater 2 is monitored by a level detector such as a float type liquid level device, and when the level reaches a predetermined level, the automatic liquid reception valve 1c and the automatic vapor return valve 1e. Close at the same time. By doing so, the LP gas heater 2 is in a sealed state with a predetermined amount of LP gas (liquid) stored. The amount of liquid flowing into the LP gas heater 2 is controlled by the two automatic valves 1c and 1e so as not to become excessive. However, in this embodiment, in order to further improve safety, the vapor return automatic The pipe on the valve 1e side is set longer than the liquid receiving automatic valve 1c side. Thereby, if the liquid level of the LP gas heater 2 comes into contact with the pipe end on the vapor return automatic valve 1e side, the internal pressures of the bulk storage tank 1 and the LP gas heater 2 are balanced and the liquid from the bulk storage tank 1 is balanced. Sending stops.

  Next, means for sending LP gas (liquid) from the LP gas heater 2 to the dispenser 3 will be described. The heating-only heat source 4 is always operated, and 75 to 80 ° C. hot water is constantly circulated in the hot water pipe. When the nozzle switch of the dispenser 3 is turned on, the hot water automatic valve 9 is opened, and the hot water circulates in the heat exchanger 5 ′ communicating with the LP gas heater 2. Then, the liquefied gas (liquid) sealed in the heat exchanger 5 ′ and the LP gas heater 2 is evaporated by the hot water, and the liquefied gas (liquid) is sent to the dispenser 3 by the self-evaporation pressure. . At this time, it goes without saying that the differential pressure sensor 6 controls the liquid delivery 6a to open according to the above conditions and procedures.

  In this embodiment, hot water is circulated outside the LP gas heater 2 to indirectly heat the LP gas (liquid) in the LP gas heater 2. This is because, when heated directly, vapor is generated when LP gas (liquid) evaporates. If this vapor is mixed into LP gas (liquid) delivered to the dispenser 3, the dispenser 3 accurately detects the vapor. This is because the liquid transfer and filling amount cannot be measured. That is, in this embodiment, the LP gas heater is divided into a warm water warming part (heater 5) including a heat exchanger 5 'and a pressurized container part to prevent vapor from entering.

  Furthermore, in this embodiment, a liquid delivery valve 6a is provided as a relief valve between the LP gas heater 2 and the dispenser 3, and the valve 6a is controlled to be opened and closed by an electric differential pressure sensor 6 (comparator). However, it is also possible to employ a valve structure that is mechanically controlled to open and close by a control pressure in the same manner as the liquid receiving automatic valve 1c and the like.

  FIG. 2 shows a second embodiment of the present invention, in which a system for transferring and filling LP gas (liquid) from the tank truck 20 to the bulk storage tank 20a is constructed. The LP gas (liquid) is transferred from the tank truck 20 to the LP gas heater 20b by its own weight, and the LP gas (liquid) in the LP gas heater 20b is pressurized by hot water heating and transferred to the bulk storage tank 20a. The main principle is not different from the first embodiment described above. Therefore, there is a difference in configuration from the above embodiment, whether the supply source is the tank truck 20 or the bulk storage tank, the supply destination is the bulk storage tank 21 or the dispenser (LP gas car). The difference that should be noted is that a radiator of a tank truck is used as a means for generating hot water. Since other circuit configurations are the same as those in the first embodiment and the operation principle is the same, those skilled in the art can understand even if the detailed description of the second embodiment is omitted. Will.

  Furthermore, when the modification accompanying this invention is demonstrated, the number of a bulk storage tank and LP gas heater is not limited to 1 unit | set, Two or more units | sets may be sufficient. In particular, when two or more LP gas heaters are provided, all of them can be operated simultaneously or exclusively depending on the arrangement of the switching valves.

  Therefore, according to FIG. 3, a third embodiment of the present invention in which two LP gas heaters are provided will be described. In this embodiment, LP gas heaters 21 and 22 are connected to the bulk storage tank 11 in parallel, a pressure equalization bypass valve 31 is connected to the gas phase side, and a hot water bypass valve 32 is connected to the hot water circulation path. Both LP gas heaters 21 and 22 are switched by the bypass valves 31 and 32. The LP gas heaters 21 and 22 are respectively provided with gas phase side pressure equalizing valves 41 and 42, liquid inlet valves 51 and 52, hot water inlet valves 61 and 62, and liquid outlet valves 71 and 72, respectively. The surface gauges 81 and 82 always detect the liquid level drop of the LP gas heaters 21 and 22. Reference numerals 91 and 92 denote hot water heaters installed outside the LP gas heaters 21 and 22 for indirectly heating the LP gas liquid in the LP gas heaters 21 and 22.

  The operation of the system having the above configuration will be described. First, in the standby state, the pressure equalizing valves 41 and 42 and the liquid inlet valves 51 and 52 of the LP gas liquid heaters 21 and 22 are opened, and the bulk storage tank 11 sequentially With the LP gas liquid dropped into the LP gas liquid heaters 21 and 22, all the valves connected to the heaters 21 and 22 other than the hot water bypass valve 32 are closed. Next, as preparation for filling, the dispenser 100 is turned on, and the hot water inlet valve 61 on the LP gas heater 21 side is opened to heat the LP gas liquid in the heater 21, and the vapor pressure thereof is increased. To increase to a predetermined pressure. At this time, the hot water bypass valve 32 is closed. Then, by opening the liquid outlet valve 71, the LP gas heater 21 starts filling the LP gas liquid into the LP gas wheel (not shown), and the liquid level of the heater 21 is lowered by the liquid level gauge 81. Is detected, the other LP gas warmer 22 is prepared for pressurization. That is, in this case, the pressure equalization bypass valve 31 is opened, and the pressure-increased gas phase of the LP gas heater 21 is communicated with the gas phase of the other heater 22, thereby equalizing the gas pressures of both. To. The advantage of this configuration is that one gas phase pressure is used as the other liquid delivery pressure when the heater is switched, and therefore the LP gas liquid heating time is short. When the pressure equalization bypass valve 31 is opened, the vapor pressures of the two heaters 21 and 22 are almost instantaneously equalized. Thereafter, the pressure equalization bypass valve 31 is closed and one LP gas heater 21 is closed. The warm water inlet valve 61 is closed, and at the same time, the warm water inlet valve 62 and the liquid outlet valve 72 of the other LP gas warmer 22 are opened, whereby the LP gas liquid by the other LP gas warmer 22 is opened. The filling operation is started. At this time, with respect to one of the heaters 21, the LP gas liquid dropping from the bulk storage tank 11 is also performed in parallel by opening the pressure equalizing valve 41 and the liquid inlet valve 51. When the liquid level of the LP gas warmer 22 is detected as Low by the liquid level gauge 82, the pressure equalization bypass valve 31 is opened again, and the gas phase of the other warmer 22 whose liquid has been lowered this time. The pressure is used as the liquid delivery pressure of one heater 21.

  Thereafter, the above switching operation is repeated until a predetermined amount of LP gas liquid, such as a full tank, is supplied to the LP gas vehicle. When the supply is completed, a flow meter stop signal from the dispenser 100 is received, The operation of stopping the pressurization of each warmer and dropping the liquid from the bulk storage tank 11 to each warmer is performed.

  In the above operation flow, the filling by one heater 21 and the pressure equalization operation with the other heater 22, the filling start operation with the other heater 22, and the LP gas liquid dropping into the one heater 21. It is preferable that the operation, the completion of filling by the other heater 22 and the operation of dropping the LP gas liquid into the heater 22 are performed almost simultaneously. Further, in order to keep the filling flow rate at the time of switching the heater from changing, even if the liquid level gauge 81 of one heater 21 detects Low, the other heater 22 starts filling. It is preferable to continue filling with one of the heaters 21.

Circuit diagram of the system of the present invention according to the first embodiment Circuit diagram of the system of the present invention according to the second embodiment Circuit diagram of the system of the present invention according to the third embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bulk storage tank 2 LP gas heater 3 Dispenser 4 Heating exclusive machine 5 Heater 6 Electric differential pressure sensor 7 Liquid phase line 8 Relief valve 9 Hot water automatic valve 10 Control pressure generator

Claims (9)

The LP gas is stored in a liquid state, and the LP gas liquid can be sent out by head pressure or / and its own weight, and a predetermined amount of LP gas liquid is received from the tank device, and then the gas phase portion is added in a sealed state. The LP gas warmer capable of delivering LP gas liquid by being pressurized, and the LP gas warmer in the LP gas warmer by heating the LP gas liquid in the LP gas warmer and generating vapor pressure. A liquefied gas transfer and filling system comprising a heat source for pressurizing a phase portion and a transfer and filling destination device to which an LP gas liquid is delivered from an LP gas heater.   The liquefied gas transfer and filling system according to claim 1, wherein the heat source is warm water heated by a heater.   A liquid delivery valve is provided on the transfer gas filling means side of the LP gas heater, and the liquid delivery valve is controlled to open and close by the differential pressure between the gas phase pressure of the storage tank device and the LP gas heater pressure pressurized by the heater. The liquefied gas transfer and filling system according to claim 1 or 2.   The liquefied gas transfer / filling system according to claim 1, wherein a liquid delivery valve is provided on the transfer / filling destination means side of the LP gas heater, and the liquid delivery valve is controlled to be opened and closed by an air valve.   The liquefied gas transfer and filling system according to claim 1 or 2, wherein a liquid delivery valve is provided on the transfer and filling destination means side of the LP gas heater, and the liquid delivery valve is controlled to be opened and closed by an electromagnetic valve.   Two LPG gas warmers are provided in parallel, each warmer is provided with a liquid level gauge, the gas phase portions of both warmers are connected by a delivery valve, and the delivery valve is connected by the liquid level gauge. Opening / closing control is performed by a detected LP gas liquid lowering signal of one heater, and the gas phase pressure of one heater is applied to the delivery pressure of the LP gas liquid of the other heater. The liquefied gas transfilling system according to 3, 4 or 5.   The liquefied gas transfer and filling system according to any one of claims 1 to 6, wherein the storage tank device is an LP gas liquid bulk storage tank and the transfer and filling destination device is an LP gas vehicle via a dispenser.   The liquefied gas transfer and filling system according to any one of claims 1 to 6, wherein the storage tank device is an LP gas liquid tank lorry vehicle, and the transfer and filling destination device is an LP gas liquid bulk storage tank.   The liquefied gas transfer and filling system according to claim 8, wherein the heater is a radiator of a tank truck.

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