JP2003214597A - Hydrogen supply device using lng - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an efficient and serviceable hydrogen supply device. <P>SOLUTION: This hydrogen supply device uses LNG, and manufactures hydrogen from the LNG, and comprises an LNG tank for storing the LNG, a vaporizer connected to the LNG tank, a pump for sending out the LNG to the vaporizer from the LNG tank, a hydrogen manufacturing device for manufacturing the hydrogen by using the gas from the vaporizer, a gas flowmeter for measuring a gas flow rate sent out to the hydrogen manufacturing device, a return valve for returning the LNG from the pump to the LNG tank, and a control device for opening-closing the return valve according to the flow rate measured by the gas flowmeter. <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 hydrogen supply device, and more particularly to a hydrogen supply device using LNG (liquefied natural gas) as a raw material.

[0002]

2. Description of the Related Art Conventionally, hydrogen has been generally produced from city gas by using a membrane reformer or the like.

For example, a hydrogen gas station for filling a hydrogen automobile with hydrogen is equipped with a pipe for supplying city gas, a membrane reformer, etc., city gas is sent to the membrane reformer to produce hydrogen, and the produced hydrogen is produced. Was stored in a hydrogen storage alloy, a tank, or the like, and hydrogen was appropriately supplied from a storage facility to a hydrogen automobile or the like as needed.

[0004]

When a hydrogen automobile is filled with hydrogen at a hydrogen gas station or the like, cold heat is required on the side of the hydrogen automobile. Conventionally, the refrigerant is cooled by a radiator, a compressor, etc. It was sent to a hydrogen vehicle and the storage device of the hydrogen vehicle was cooled to a predetermined state.

Further, since the membrane reformer has a property that the higher the primary pressure is, the more easily it can permeate through the membrane, in order to produce hydrogen from city gas using the membrane reformer,
The pressure of city gas to the membrane reformer must be increased, and conventionally, a compressor is installed to pressurize the city gas, and the compressor is operated to increase the supply pressure of city gas. Therefore, the facility cost was large, and it cost much to install the hydrogen supply base.

Since city gas is used as a raw material, LNG
Costs increased due to the use of storage equipment, vaporization equipment, odor equipment, etc. at the base, as well as gas conduits, governor stations, etc., and in some cases, desulfurization equipment, etc., for removing sulfur content was required.

[0007]

According to the present invention, in order to solve the above problems, a hydrogen supply device using LNG is constructed as follows.

That is, in a hydrogen supply apparatus for producing and supplying hydrogen from LNG, an LNG tank for storing LNG, a vaporizer connected to the LNG tank, a pump for sending LNG from the LNG tank to the vaporizer, and A hydrogen production apparatus for producing hydrogen using gas from the vaporizer, a gas flow meter for measuring the flow rate of gas delivered to the hydrogen production apparatus, a return valve for returning LNG from the pump to the LNG tank, And a control device for opening and closing the return valve according to the flow rate measured by the gas flow meter.
A hydrogen supply device using was constructed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a hydrogen supply device using LNG according to the present invention will be described.

FIG. 1 shows the overall structure of the hydrogen supply device.
As shown in FIG. 1, the hydrogen supply device 2 includes an LNG tank 4
It comprises a vaporizer 6, a compressor 8, a hydrogen production device 10, a hydrogen storage device 12, a control device 14 and the like.

The LNG tank 4 is a storage device for inflowing and storing LNG carried by a tank truck or the like.
The vaporizer 6 is a device that is connected to the LNG tank 4 via the pump 21 and vaporizes the LNG liquefied gas sent from the LNG tank 4 by the pump 21. The pump 21 constantly delivers a constant LNG. The compressor 8 compresses the gas vaporized by the vaporizer 6 to a predetermined pressure and CNG as CNG.
Supply to stations, etc.

The hydrogen production apparatus 10 is composed of a membrane reformer or the like and converts natural gas into hydrogen. The hydrogen production device 10 is not limited to the membrane reformer, and may be other means. The hydrogen storage device 12 is a hydrogen storage alloy, a liquefied hydrogen storage tank, or the like, and stores the hydrogen produced by the hydrogen production device 10. The hydrogen storage device 12 is connected to a hydrogen gas station or the like. In addition, LNG tank 4
A return pipe for returning LNG to the LNG tank 4 and an adjusting device 19 for adjusting the flow rate of the return pipe are installed between the and the vaporizer 6.

The control device 14 is connected to the adjusting device 19 and sends a control signal to the adjusting device 19 to adjust the return amount of the LNG to the LNG tank 4. Also, the vaporizer 6 and the compressor 8
Flowmeters 7 and 9 are connected between the vaporizer 6 and the hydrogen production apparatus 10, and the flow rate is measured by these and sent to the controller 14. Thereby, the inflow amount of LNG to the hydrogen production device 10 and the compressor 8 is monitored, and the return amount of the adjustment device 19 is adjusted to adjust the LNG from the LNG tank 4.
The amount can be controlled so that it can be delivered exactly.

Further, according to the hydrogen supply device 2 using the above LNG, since the LNG is vaporized on the spot, it is easy to raise the pressure, and when the hydrogen production device 10 is a membrane reformer, the membrane reformer is the primary one. The higher the pressure, the easier it is for the membrane to permeate, so the efficiency of the membrane reformer can be increased. Further, since LNG does not contain a sulfur content, a desulfurization device is unnecessary, and further, by introducing CNG (compressed natural gas) from the compressor 8 into a CNG stand or the like and using CNG, efficiency can be increased.

Further, the cold heat of LNG is utilized in the hydrogen production device 10 and the hydrogen storage device 12 in the production and storage processes, and the refrigerant is further cooled by the cold heat to be used for cooling when supplying hydrogen to the natural gas vehicle. be able to. Further, BOG (vaporized gas) in the LNG tank 4 can be directly used for the burner of the hydrogen production device 10, and the BOG processing device can be omitted.

Further, by utilizing the exhaust heat from the hydrogen production device 10,
It can be used as a heat fence for the LNG tank 4, and the running cost can be reduced.

Another example is shown in FIG.

This is the outflow pump 21 of the LNG tank 4.
An inverter 23 for controlling the rotation speed is attached to the.
In this case, the inflow amount of LNG to the compressor 8 and the hydrogen production device 10 is monitored, and the outflow amount from the LNG tank 4 is controlled by adjusting the outflow amount of the outflow pump 21 according to the increase / decrease. Even in this case, it is possible to control the total LNG transmission amount without excess or deficiency.

In FIG. 3, adjusting valves are provided on the inflow sides of the hydrogen producing device 10 and the compressor 8, respectively, and an adjusting device 19 is also provided on the return pipe. Further, a buffer tank 24 is installed in the latter stage of the vaporizer 6, and the buffer tank 24
Internal pressure is sent to the controller 14. Hydrogen storage device 1
A flow meter is attached to each of the outflow pipes of the compressor 2 and the compressor 8.

According to this, the adjusting device 19 is controlled so that the internal pressure of the buffer tank 24 becomes constant, and the adjusting valve is adjusted according to the outflow amount from the hydrogen storage device 12 and the compressor 8. Therefore, the hydrogen storage device 12 and the compressor 8
The adjusting valve can be adjusted according to the outflow amount from the tank, and appropriate control can be performed, and the buffer tank 24 can cope with such a variation in the used amount.

FIG. 4 shows an example in which the refrigerant cooled by utilizing the cold heat of the vaporizer 6 is sent out from the vaporizer 6. The temperature and flow rate of the refrigerant to be sent out are measured and sent to the control device 14. The controller 14 adjusts the return amount of the return valve based on the refrigerant temperature and the flow rate value.

In this case, the temperature and flow rate of the refrigerant can be measured, and the amount of return to the LNG tank 4 can be adjusted according to the amount of recovered cold heat to keep the cooling capacity of the refrigerant constant. Further, when the buffer tank 24 is provided, even if the required amount of the refrigerant is increased and the outflow amount from the LNG tank 4 is increased, LNG can be temporarily stored in the buffer tank 24, so that the operation can be performed more efficiently.

FIG. 5 is an example in which a refrigerant utilizing the cold heat of the vaporizer 6 is sent out from the vaporizer 6 as in FIG. 4, and the control device 14 measures the temperature and flow rate of the refrigerant to be sent out.
Send to. The controller 14 adjusts the LNG flow rate from the LNG tank 4 to the required amount of the refrigerant by increasing or decreasing the rotation speed of the outflow pump based on the refrigerant temperature and the flow rate value.

FIG. 6 shows an example in which the valve is opened and closed so that the internal pressure in the LNG tank 4 becomes constant, and the gas is discharged. At the upper part of the LNG tank 4, a pipe for flowing out gas vaporized in the LNG tank 4 and an on-off valve 25 for the pipe are provided.
A measuring unit 27 that measures the internal pressure and opens and closes the on-off valve at a predetermined pressure is provided. For example, LNG tank 4
The internal pressure of is maintained at about 0.1 to 0.12 MPa. Then, the operation of the hydrogen production apparatus 10 is controlled in accordance with the combustion amount of the gas taken out to adjust the internal pressure by the burner.

According to this, the internal pressure of the LNG tank 4 does not become excessive, the wall surface of the tank can be made thin, and the design,
Construction becomes easy. Further, instead of the internal pressure of the LNG tank 4, a flow meter may be provided in the pipe and the on-off valve may be controlled so that the outflow amount of gas is constant.

In FIG. 7, as in FIG. 4, a refrigerant utilizing the cold heat of the vaporizer 6 is sent from the vaporizer 6 to the hydrogen storage device 12 for cooling the hydrogen storage alloy in the hydrogen storage device 12. This is the example used. As a result, the hydrogen storage device 12
The hydrogen storage alloy can be cooled and a large amount of hydrogen can be stored. It should be noted that the temperature and flow rate of the refrigerant to be sent out are respectively measured, and the LNG flow rate is adjusted to the required amount of the refrigerant based on the temperature and flow rate value of the refrigerant.

FIG. 8 shows an example in which the refrigerant of FIG. 7 is sent to the compressor 16 to be cooled. The compressor 16 increases the pressure of hydrogen to F
This is a device for sending to a CV or the like, and heat generated by compression is cooled by a refrigerant. As a result, it is possible to prevent the compressor 16 from overheating and prevent burns and damage to the device.

[0028]

According to the hydrogen supply device using LNG of the present invention, the cold heat and vaporization pressure possessed by LNG can be effectively utilized, and the number of times switching is stopped can be reduced to enable stable continuous operation. A hydrogen supply device with high operating efficiency can be provided.

Further, it is possible to efficiently supply hydrogen to a hydrogen automobile or the like by using the cold heat or the like of LNG.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a hydrogen supply device using LNG of the present invention.

FIG. 2 is a diagram showing another embodiment of a hydrogen supply device using LNG of the present invention.

FIG. 3 is a diagram showing another embodiment of a hydrogen supply device using LNG of the present invention.

FIG. 4 is a diagram showing another embodiment of a hydrogen supply device using LNG of the present invention.

FIG. 5 is a diagram showing another embodiment of a hydrogen supply device using LNG of the present invention.

FIG. 6 is a diagram showing another embodiment of a hydrogen supply device using LNG of the present invention.

FIG. 7 is a diagram showing another embodiment of a hydrogen supply device using LNG of the present invention.

FIG. 8 is a diagram showing another embodiment of the hydrogen supply device using LNG of the present invention.

[Explanation of symbols]

2 Hydrogen supply device 4 LNG tank 6 vaporizer 8, 16 compressor 10 Hydrogen production equipment 12 Hydrogen storage device 14 Control device

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kunihiro Nishizaki             1-5-20 Kaigan, Minato-ku, Tokyo Tokyo Gas             Within the corporation F-term (reference) 3E073 DB05                 3J071 AA23 BB02 BB03 BB11 BB14                       CC03 CC11 CC16 EE02 EE24                       EE25 FF03

Claims (8)

[Claims] 1. A hydrogen supply device for producing and supplying hydrogen from LNG, an LNG tank for storing LNG, a vaporizer connected to the LNG tank, a pump for sending LNG from the LNG tank to the vaporizer, and the vaporization A hydrogen production device for producing hydrogen using gas from a gas vessel, a gas flow meter for measuring the flow rate of gas delivered to the hydrogen production device, a return valve for returning LNG from the pump to the LNG tank, A hydrogen supply device using LNG, comprising a control device for opening and closing the return valve according to a flow rate measured by a gas flow meter. 2. A hydrogen storage device is connected to the hydrogen production device, hydrogen produced by the hydrogen production device is stored in the hydrogen storage device, and hydrogen is supplied from the hydrogen storage device. A hydrogen supply device using the LNG according to Item 1. 3. The hydrogen supply device using LNG according to claim 1, wherein a compressor is connected to the vaporizer to supply compressed natural gas. 4. The hydrogen supply device using LNG according to claim 1, wherein the outflow amount of the pump is adjusted. 5. A buffer tank is provided on the downstream side of the vaporizer, the pressure in the buffer tank is measured, the return valve is controlled so that the internal pressure becomes a constant value, and the hydrogen storage device and The LNG according to claim 4, wherein the outflow amount from the compressor is measured, and the inflow amount of LNG to the hydrogen production device and the compressor is adjusted based on the outflow values. Hydrogen supply device. 6. The LNG according to claim 4, wherein the vaporizer is provided with a heat exchanger for cooling the refrigerant, and the return valve is adjusted so that the temperature and the flow rate of the refrigerant are constant. There was a hydrogen supply device. 7. The hydrogen supply device using LNG according to claim 6, wherein the rotation speed of the pump is adjusted to keep the temperature and the flow rate of the refrigerant constant. 8. The vaporized gas in the LNG tank is sent to the hydrogen production device via a heat exchanger, and a regulating valve for adjusting the outflow amount of the vaporized gas is adjusted so that the pressure inside the LNG tank becomes constant. The hydrogen supply device using LNG according to claim 3, characterized in that the hydrogen supply device is controlled according to the above.