JPH05215297A - Heating and decompressing system commonly used for gaseous phase of liquefied gas - Google Patents

Abstract

PURPOSE:To lengthen the service life of a vaporizing cylinder and a solenoid valve as well as to prevent fluid outflow if the power should fail by constituting a system such that a first pressure regulator is set higher in operating pressure than a second pressure regulator while the opening pressure of the solenoid valve positioned upstream of the vaporizing cylinder in a first flow path is set lower than its closing pressure, and the solenoid valve is closed when electricity is off. CONSTITUTION:This system is constituted such that a first pressure regulator 1 is set higher in operating pressure than a second pressure regulator 15, a pressure switch 4 and a solenoid valve 5 opened/closed by the output signal of the pressure switch 4 are provided upstream of a vaporizing cylinder 7 in a first flow path 3, the opening pressure of the solenoid valve 5 is set higher than its closing pressure, and the solenoid valve 5 is designed to be closed when electricity is off. By this constitution, since the solenoid valve 5 is closed when the pressure of a container 1 is high, the vaporizing cylinder is not used, and gas mainly flows from the gaseous phase take-off port 13 of the container 1 through a second flow path 14 so as to be supplied to a gas consumption side 16 through the second pressure regulator 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor phase heating and depressurizing system for liquefied gas, and more particularly, to extend the life of a vaporizing cylinder, prevent malfunction of a solenoid valve, and suppress pressure fluctuation of supply gas. The present invention relates to a suitable liquefied gas vapor phase heating and decompression system.

[0002]

2. Description of the Related Art A heating and depressurizing method for vapor phase combined use of liquefied gas such as liquefied petroleum gas is derived from the vapor phase in a liquefied gas container (hereinafter referred to as "container") as the pressure in the container rises and falls. A method of supplying gas from one of a gas gas flow path and a flow path that gasifies and guides a gas liquid led from a liquid phase in the container by a heating medium to vaporize it through a vaporization cylinder. is there.

In the conventional liquefied gas vapor phase combined heating and depressurization system, the set pressure of the first pressure regulator provided downstream of the vaporization cylinder of the first flow path from the liquid phase of the container is equal to that of the container. The back pressure valve, which is set to a value slightly higher than the set pressure of the second pressure regulator provided in the second flow path introduced from the gas phase, and which is provided in the upstream flow path of the vaporization cylinder, Is designed to open when the pressure falls below the set pressure of the back pressure valve.

When the pressure in the container is high, the vaporization cylinder is not used because the back pressure valve is closed, and the gas is taken out from the gas phase of the container and supplied after being decompressed by the second pressure regulator. When the gas supply from the gas phase of the container continues, the liquid temperature decreases due to the latent heat of vaporization of the liquid phase, and the internal pressure of the container also decreases accordingly. In this way, when the pressure in the first flow path becomes equal to or lower than the set value of the back pressure valve, the back pressure valve opens and the liquid flows into the vaporization cylinder and is vaporized,
Gas is supplied after being decompressed by the first pressure regulator.

At this time, in the container, the temperature of the liquid in the container rises due to heat absorption from the outside air, and the outlet pressure of the vaporizing cylinder also rises accordingly. When the pressure in the container becomes higher than the set pressure of the back pressure valve, the back pressure valve closes, and the initial state of gas phase gas supply is entered. The above-mentioned states are alternately repeated, but in any state, the outlet pressure of the vaporizing cylinder is maintained so as not to exceed the set pressure of the back pressure valve.

[0006]

However, when the internal pressure of the container drops to the set pressure of the back pressure valve, the back pressure valve repeatedly opens and closes frequently thereafter, so that the internal pressure of the vaporizing cylinder frequently changes and the vaporizing cylinder is repeatedly stressed. Will occur. Moreover, the frequent operation also shortens the life of the back pressure valve. Furthermore, the gas pressure at the vaporization cylinder outlet continues to fluctuate.

Further, if the heat source for heating the heating medium in the vaporization cylinder is stopped during a power failure, there is a risk that the liquid from the liquid phase of the container will not be gasified and will flow out to the gas consuming side. It is necessary to provide a thermo-valve that detects the drop in medium temperature and closes the liquid inlet side.

In order to solve the above problems, the object of the present invention is to suppress the pressure fluctuation in the vaporizing cylinder, prolong the life of the vaporizing cylinder and the solenoid valve, and prevent the outflow of liquid at the time of power failure. It is to provide a heating / depressurizing system capable of using a liquefied gas in a vapor phase.

[0009]

In order to achieve the above-mentioned object, the present invention is a vaporization in which a liquefied gas container and a liquefied gas liquid introduced from a liquid phase portion of the liquefied gas container are heated and vaporized by a heating medium. A cylinder and a first flow path for guiding the liquefied gas liquid from the liquid phase part of the liquefied gas container, decompressing the liquefied gas gas vaporized in the vaporization cylinder with a first pressure regulator and supplying it to the gas consumption side, A liquefied gas vapor phase combined heating and depressurization system comprising: a second flow path for guiding a liquefied gas gas from a vapor phase portion of a liquefied gas container and decompressing it by a second pressure regulator to supply it to a gas consuming side.
The pressure regulator is set to an operating pressure higher than that of the second pressure regulator, and a solenoid valve that opens and closes according to the output signal of the pressure switch and the pressure switch is provided on the upstream side of the vaporization cylinder of the first flow path,
Provided is a liquefied gas vapor phase combined heating and depressurization system having a structure in which an opening pressure of a solenoid valve is set lower than a closing pressure and the solenoid valve is closed when not energized.

[0010]

According to the above construction, the pressure of the first pressure regulator is set to be higher than that of the second pressure regulator, and the solenoid valve provided on the inlet side of the vaporizing cylinder is opened / closed by the output signal of the pressure switch on the upstream side thereof. However, since the solenoid valve is set to have a lower opening pressure than a closing pressure, when the pressure in the container is high, the solenoid valve is closed and the vaporizer is not used. It is supplied to the gas consuming side through the second flow path and the second pressure regulator. At this time, since the first pressure regulator is open, the vaporizing cylinder internal pressure becomes the same as the gas supply pressure.

When the gas is continuously supplied from the vapor phase outlet of the container, the liquid temperature is lowered by the latent heat of vaporization of the liquefied gas liquid in the container, and the internal pressure of the container is reduced accordingly. In this way, when the pressure inside the container drops below the set pressure for opening the solenoid valve,
The solenoid valve opens and the liquefied gas liquid is introduced into the vaporization cylinder through the first flow path, and is vaporized by the heat medium in the vaporization cylinder heated by the heat source and supplied to the gas consumption side through the first pressure regulator. To be done. Since the set pressure of the first pressure regulator is higher than that of the second pressure regulator, when the first pressure regulator operates, the second pressure regulator is closed and the gas supply from the vapor phase outlet of the container is stopped.

Then, in the container, the liquid temperature rises with the heat absorption from the outside air, and the vaporizing cylinder pressure gradually rises accordingly. Then, when the pressure in the container becomes higher than the pressure for closing the solenoid valve, the solenoid valve closes, and the state of gas supply from the initial gas phase is restored.

Thus, the pressure from the opening of the solenoid valve to the pressure of closing the solenoid valve (for example, the opening pressure of 6 kgf / cm ² to the closing pressure of 9 kgf).
Since the solenoid valve remains open while the pressure in the container rises to / cm ² ), the frequency of opening and closing the valve is significantly reduced compared to the conventional system.

Further, since the electromagnetic valve which is closed when not energized is used, there is no possibility that the liquefied gas liquid will flow into the vaporizing cylinder at the time of power failure. Therefore, it is not necessary to provide a liquid inflow prevention device.

[0015]

Embodiments of the present invention will be described with reference to FIGS. The liquid of the liquefied gas taken out from the liquid phase take-out port 2 of the liquefied gas container 1 enters the vaporization cylinder 7 through the first flow path 3, and is vaporized by the heat source 10 while passing through the coiled conduit 8. It is heated and vaporized by the heat medium 9 in the cylinder, becomes a gas, exits the vaporization cylinder 7, is decompressed by the first pressure regulator 11, and is supplied to the gas consuming side 16.

A pressure switch 4 on the upstream side of the vaporization cylinder 7 of the first flow path 3, a solenoid valve 5 which is opened and closed by a signal generated by the pressure switch 4 and is closed when not energized, and a check valve for bypassing them. 12 are provided. The signal of the pressure switch 4 is transmitted to the solenoid valve 5 via the control panel 6.

On the other hand, the gas of the liquefied gas taken out from the vapor-phase take-out port 13 of the container 1 passes through the second flow path 14 and is decompressed by the second pressure regulator 15 and supplied to the gas consuming side 16. ..

The set pressure of the first pressure regulator 11 is 0.8k.
Setting pressure of the second pressure regulator 15 is 0.7 kgf at gf / cm ^2.
It is set higher than / cm ^{2 and} the second flow passage 14 is closed while the gas is being supplied from the first flow passage 3.

The operating pressure of the solenoid valve 5 from being set so as to close at 9 kgf / cm ² open at 6 kgf / cm ^2, while the pressure in the vessel 1 is higher than 9 kgf / cm ² electromagnetic valve 5 is closed The vaporization cylinder 7 is not used, and the gas is supplied from the vapor phase outlet 13 of the container to the gas consumption side 16 through the second flow path 14.

If this state continues, the temperature of the liquid in the container 1 is gradually lowered and the pressure in the container is lowered to 6 kgf /
When it becomes less than cm ² , the solenoid valve 5 opens and the use of the vaporizing cylinder 7 starts. Thus, the gas supply is transferred to the first flow path 3.

In the container 1, the liquid temperature rises due to heat absorption from the outside air, and the internal pressure also rises gradually. And the pressure is 9kgf /
When it becomes higher than cm ² , the solenoid valve 15 is closed and the state of gas supply from the gas phase is changed.

The solenoid valve actuation and the container of FIG. 2, as shown in the diagram showing the time course of vaporization cylinder pressure, while the container 1 in the pressure is increased from 6 kgf / cm ² to 9 kgf / cm ² solenoid valve 15
Since the valve is open, the opening / closing frequency of the solenoid valve 15 is significantly reduced as compared with the conventional system using the back pressure valve 21 shown in the diagram of FIG.

Further, since the solenoid valve 15 has a structure which is closed when it is not energized, it is closed when there is a power failure, so that the liquid flows into the vaporizing cylinder 7 and is not vaporized by heating but flows to the gas consuming side 16 in a liquid state. That's not it. By using such an electromagnetic valve 15, it is not necessary to provide a liquid inflow prevention device by the thermo valve 22 unlike the conventional system shown in FIG.

[0024]

According to the present invention, since the electromagnetic valve that opens in a predetermined pressure fluctuation range of the internal pressure of the liquefied gas container is provided in the liquid flow path from the liquid phase outlet of the container to the vaporizer, the frequency of opening and closing the electromagnetic valve is increased. Is reduced, pressure fluctuations in the vaporization cylinder are slowed down, occurrence of failures in the vaporization cylinder and the solenoid valve can be suppressed, and the life can be extended.

Further, since the solenoid valve has a structure which is closed when not energized, it is possible to prevent the risk that the liquid flow path is closed at the time of power failure and the liquid flows to the gas consuming side.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of a liquefied gas vapor phase combined heating and depressurizing system of the present invention.

FIG. 2 is a diagram showing changes over time in solenoid valve operation, container internal pressure, and vaporization cylinder internal pressure according to an embodiment of the present invention.

FIG. 3 is an overall configuration diagram of a conventional liquefied gas vapor phase combined heating and decompression system.

FIG. 4 is a diagram showing changes over time in back pressure valve operation, container pressure, and vaporization cylinder pressure in the conventional system of FIG.

[Explanation of symbols]

 1 Liquefied gas container 2 Liquid phase outlet 3 First flow path 4 Pressure switch 5 Solenoid valve 6 Control panel 7 Vaporization cylinder 8 Coiled conduit 9 Heat medium 10 Heat source 11 First pressure regulator 12 Check valve 13 Gas phase extraction Port 14 Second flow path 15 Second pressure regulator 16 Gas consumption side 21 Back pressure valve 22 Thermo valve

Claims (1)

[Claims] 1. A liquefied gas container, a vaporization cylinder that heats and vaporizes a liquefied gas liquid introduced from a liquid phase portion of the liquefied gas container by a heating medium, and a liquid from the liquid phase portion of the liquefied gas container. A first flow path for guiding the liquefied gas gas vaporized in the vaporization cylinder by the first pressure regulator to supply it to the gas consuming side, and for guiding the liquefied gas gas from the gas phase portion of the liquefied gas container. In a liquefied gas vapor phase combined warming depressurization system including a second flow path that is depressurized by two pressure regulators and supplied to the gas consuming side, the first pressure regulator is higher than the second pressure regulator. A pressure switch and a solenoid valve that opens and closes according to an output signal of the pressure switch are provided on the upstream side of the vaporization cylinder in the first flow path, and the opening pressure of the solenoid valve is set to be lower than the closing pressure. In addition, the solenoid valve has a structure that closes when it is not energized. A heating and decompression system for combined use with a liquefied gas and a vapor phase.