JPH09273817A - Low temperature generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To economically produce cold-heat by a method wherein liquid hydrogen cooled by a heat exchanger is stored in a liquid hydrogen storage tank, sent to an evaporator through an expansion valve, where the hydrogen is used for direct cooling or for cooling an indirect refrigerant, and then sent to a compressor to pressurize it. SOLUTION: Hydrogen absorbs heat and evaporates to gas in an evaporator 18 and the hydrogen gas is sucked and compressed by a compressor 3 up to a pressure at which the hydrogen gas can be liquefied when cooled down to a cooling temperature of a heat exchanger 2. The Compressed hydrogen gas is stored in a pressure accumulator 5 of a pressure vessel. The compressed hydrogen gas having a specified pressure is released through an automatic valve 7. A low temperature generator is provided with the heat exchanger 2 to cool and liquefy the compressed hydrogen gas, a cryogenic liquefied gas storage tank where refrigerant to cool the heat exchanger 2 is stored, and a liquid hydrogen storage tank 14 to store liquid hydrogen. The liquefied high- pressure liquid hydrogen is depressurized by an expansion valve 16 and absorbs heat from the surroundings via the evaporator 18 when the liquid hydrogen evaporates.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a low temperature generator such as a compression type refrigerating device.

[0002]

2. Description of the Related Art Conventionally, a compression refrigerating apparatus uses freon gas as a refrigerant, compresses the freon gas and liquefies it in a condenser, and sends it to an evaporator from an expansion valve to obtain a low temperature by evaporating the freon liquid.

Freon gas, ammonia gas, carbon dioxide gas, and sulfurous acid gas are known as conventional refrigerants. Among them, Freon gas has dominated most because of its excellent performance.

[0004]

However, because Freon gas is an environmental pollution that causes the destruction of the ozone layer,
It is being banned globally. Alternative CFCs have also been researched, but none have been developed that satisfy their performance. Ammonia gas and sulfurous acid gas are toxic and dangerous to the human body, and carbon dioxide gas is difficult to use because it has a low liquefaction temperature and is difficult to liquefy at room temperature.

The present invention solves the above-mentioned conventional problems, and is a low-temperature cooling type heat exchange device for hydrogen gas (Public utility model No. 2764 published in 1995, and Japanese Patent No. 294162 published in 1995). A large amount of hydrogen is liquefied safely and economically by passing it through (as described), and the latent heat of vaporization of the liquid hydrogen is used to replace the conventional refrigerant such as Freon gas. Nitrogen, LNG, etc. can be used as the refrigerant for cooling the heat exchange device, and the evaporated nitrogen gas, natural gas, etc. are sent to the user side with the latent heat removed as they are. It can also be used. Therefore, using liquid hydrogen produced at low cost,
It is an object of the present invention to provide a low temperature generator such as a refrigerating device that can economically extract cold heat.

[0006]

To achieve the above object, the present invention provides a heat exchange container for supplying and discharging a heat transfer medium,
A plurality of circumferential flow passages provided in the heat transfer medium in the heat exchange container and arranged in parallel and communicating in the circumferential direction, and the positions of the inlet and the outlet in each circumferential flow passage are displaced in the circumferential direction. A heat exchange flow path for a heat exchange device, which comprises an inflow port and an outflow port provided in the circumferential flow path, and a communication flow path communicating the inflow port and the outflow port between the circumferential flow paths, and the heat exchange flow. This is a low-temperature generator including a heat exchange device having a fluid supply passage and a discharge passage that are in communication with the passage, a compressor, an expansion valve, and an evaporator.

It is preferable to provide a liquid hydrogen storage tank or connect a pressure accumulator.

A heat transfer medium discharge pipe connected to the heat exchange container for discharging a heat transfer medium used for cooling liquid hydrogen, and a cooling device for the pressure accumulator and the liquid hydrogen storage tank connected to the pipe. May be included.

[0009]

The liquid hydrogen cooled by the heat exchange device is the second aspect.
In the described invention, it is stored in a liquid hydrogen storage tank, which liquid hydrogen is sent via an expansion valve to an evaporator where it is used for direct cooling or for cooling an indirect refrigerant. The hydrogen gas that has passed through the evaporator is sent to a compressor where it is pressurized, and further,
In the described invention, after being accumulated in the pressure accumulator, it is sent to the heat exchange device and cooled by the heat transfer medium.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of an essential part showing a heat exchange device in one embodiment of the present invention, and FIG. 2 is a schematic system diagram showing an example of use when the heat exchange device is immersed in a liquid nitrogen refrigerant.

In this embodiment, the compressor 3 absorbs heat by the evaporator 18 to absorb the evaporated hydrogen gas and compresses the hydrogen gas to a pressure at which the hydrogen gas can be liquefied at the cooling temperature of the heat exchanger 2. Accumulator 5 which is a pressure vessel for storing hydrogen gas, automatic valve 7 for releasing hydrogen gas at a predetermined pressure, heat exchange device 2 for cooling and liquefying compressed hydrogen gas, and refrigerant for cooling this heat exchange device. For storing ultra-low temperature liquefied gas (liquid hydrogen storage tank 1 in this embodiment), liquid hydrogen storage tank 14 for storing liquefied liquid hydrogen, and expansion for depressurizing liquefied high-pressure liquid hydrogen to a pressure at which evaporation can be caused by a throttling action. It is provided with a valve 16 and an evaporator 18 that absorbs ambient heat when liquid hydrogen evaporates.

The refrigerant for cooling the hydrogen gas must be a refrigerant having a Joule-Thomson inversion temperature of hydrogen gas of -80 ° C or lower, and liquid nitrogen (-196 ° C), liquid oxygen (-183 ° C), Liquid argon (-186 ° C), L
Ultra low temperature liquefied gas such as NG (-162 ° C) is considered.
In this embodiment, an example using liquid nitrogen is shown.

As shown in FIG. 2, the liquid nitrogen storage tank 1 can store liquefied nitrogen at -196.degree. C., and the liquid nitrogen storage tank 1 has an internal utility model No. 2764 published in 1995 and a public application in 1995. The heat exchange device 2 described in Japanese Patent No. 294162 is installed. This heat exchange device 2 has a liquid hydrogen storage tank 14
And a pipe (discharging passage) 13, and an automatic valve 7 and a pipe (supplying passage) 8. The hydrogen gas compressed by the compressor 3 is accumulated in the pressure accumulator 5 via the pipe 4. The pressure accumulator 5 is connected to an automatic valve 7 by a pipe 6. Liquid nitrogen is supplied into the liquid nitrogen storage tank 1 through the pipe 10 by the valve 9.

Liquid hydrogen cooled and liquefied by the heat exchange device 2 is sent to a liquid hydrogen storage tank 14 through a pipe 1 (exhaust path) 13. Liquid hydrogen is stored in the liquid hydrogen storage tank 14. The liquid hydrogen storage tank 14 is connected to the expansion valve 16 by a pipe 15. The expansion valve 16 is connected to the evaporator 18 by a pipe 17. As the evaporator, there are a bare tube coil type, a fin coil type, a vertical tube type evaporator, a Herringhorn evaporator, etc. for cooling gas, and a cell tube type, a cell coil type for liquid cooling. There are formulas. Liquid hydrogen evaporates in the evaporator 18 through the expansion valve 16. Evaporator 18 is piping 1
It is communicated with the compressor 3 by 9, and the evaporated hydrogen gas is sent to the compressor 3.

Liquid nitrogen storage tank 1, liquid hydrogen storage tank 14, heat exchange device 2, compressor 3, indirect refrigerant material compressor 23, pressure accumulator 5, pressure accumulator sealed container 12, valve 9, expansion valve 16, automatic valve 7, Evaporator 18, cooler 21, pipes 4, 6, 8 (supply passage), pipes 10, 11, 13 (discharge passage), pipes 15, 1
7, 19, 20, 22, 24 are materials that can withstand low temperatures,
For example, it is formed of stainless steel, aluminum, copper or the like.

The operation of the above configuration will be described below. As shown in FIG. 2, the liquid nitrogen storage tank 1 can store liquid nitrogen at −196 ° C., and the heat exchange device 2 described in 1995 Patent Publication No. 2764 is provided inside the liquid nitrogen storage tank 1. is set up. This heat exchange device 2 communicates with a liquid hydrogen storage tank 14 for storing liquid hydrogen and a pipe (discharging passage) 13, and with an automatic valve 7 for discharging pressurized hydrogen gas and a pipe (supplying passage) 8. Has been done.

The hydrogen gas compressed by the compressor 3 is accumulated in the pressure accumulator 5. The pressure accumulator 5 is covered with a pressure accumulator airtight container 12, and is cooled by the just evaporated low temperature nitrogen gas sent through the pipe 11. The hydrogen gas cooled by the low temperature nitrogen gas in the pressure accumulator is liquefied when it is continuously pressurized by the compressor and supplied to the heat exchange device 2 cooled at the cooling temperature of liquid nitrogen (-196 ° C.). When the pressure reaches, the automatic valve 7 is opened, so that the heat exchange device 2 is supplied through the pipe 6 and the pipe (supply passage) 8. Since the heat exchange device 2 is cooled at the liquid nitrogen temperature of −196 ° C., the hydrogen gas is liquefied by the heat exchange device 2. The liquid nitrogen deprived of latent heat is evaporated into low-temperature nitrogen gas, which is sent to the use side after cooling the pressure accumulator 5 through the pipe 11, but since it is heated, the use condition of the nitrogen gas on the use side is used. Will be easier. The liquid nitrogen storage tank 1 has a pipe 10
And a valve 9 is provided in the pipe. The refrigerant (liquid nitrogen) is supplied to the liquid nitrogen storage tank 1 through the valve 9. The liquid hydrogen liquefied in the heat exchange device 2 is sent to the liquid hydrogen storage tank 14 through the pipe (discharging path) 13.
The liquid hydrogen stored in the liquid hydrogen storage tank 14 is sent to the expansion valve 16 through the pipe 15. The liquid hydrogen is depressurized by the expansion valve 16 to a pressure that causes vaporization, and is sent to the evaporator 18 through the pipe 17. The liquid hydrogen, which has been reduced in pressure and has reached an ultra-low temperature, causes an evaporation action in the evaporator 18 to absorb ambient heat. The hydrogen gas heated by the evaporator 18 is connected to the pipe 19
Through to the compressor 3. Since the hydrogen gas returned to the compressor 3 is a low temperature gas, it has a small specific volume and reduces the load on the compressor.

Since the temperature of the evaporated hydrogen gas is an ultra-low temperature of -250 ° C. or less, cold heat is absorbed and transferred through the indirect refrigerant in the evaporator 18. Indirect refrigerant materials include helium gas, hydrogen gas, argon gas, nitrogen gas, air,
A gas having a low boiling point such as methane gas may be considered. Evaporator 1
The indirect refrigerant material cooled in 8 is sent to the cooler 21 in the freezer compartment 25 by the pipe 20. After cooling the inside of the freezer compartment 25 by the cooler 21, the heated indirect refrigerant material passes through the pipe 24 by the indirect refrigerant material compressor 23 and the evaporator 1
It is returned to 8 and cooled again. The cooled indirect refrigerant material is sent again to the cooler 21 through the pipe 20, and the refrigeration cycle is repeated.

Since the hydrogen gas leaving the evaporator 18 and returning to the compressor 3 is still a very low temperature hydrogen gas, the specific volume of the gas is small and the power of the compressor can be reduced. The low-temperature hydrogen gas discharged from the compressor 3 is cooled in the turbulent expansion process by the heat exchange device 2 cooled to -196 ° C. of liquid nitrogen, but the thermal conductivity of the hydrogen gas is 415.5 (Cal / cm / S /
Also due to C), the transfer of cold heat is large and the liquefaction rate is large. Further, the liquid temperature of hydrogen gas as a refrigerant is −250 ° C. or lower, and the range of cold heat to be taken out is large and the utilization is large. By filling the heat exchange device with a refrigerant and replenishing the amount used for the liquefaction of hydrogen and evaporating, liquid hydrogen can be produced without a problem in the structure of the device. Further, the liquefied gas as the evaporating refrigerant can be sent to the place of use in the state where the latent heat is removed and consumed, so that the economical production of liquid hydrogen can be performed.

The only power used is the hydrogen gas compressor and the power of the indirect refrigerant material compressor, and liquid nitrogen gas for cooling hydrogen gas can be reused as nitrogen gas, so it is an economical refrigerator. it can.

The embodiments of the present invention are not limited to those described above. For example, the present invention may be applied not only to the indirect cooling method as described above but also to a direct cooling method in which direct cooling is performed by an evaporator. It is also possible to provide a pipe from the liquid nitrogen storage tank to the liquid hydrogen storage tank, cover the liquid hydrogen storage tank with a closed container, and cool the liquid hydrogen storage tank with the low temperature nitrogen gas from the liquid nitrogen storage tank.

[0022]

EFFECTS OF THE INVENTION Since the present invention is configured as described above, it has an excellent effect that an efficient low temperature generator such as a refrigerator can be economically provided.

[Brief description of drawings]

FIG. 1 is a perspective view of essential parts showing a heat exchange device according to an embodiment of the present invention.

FIG. 2 is a schematic system diagram of a refrigerator that uses liquid hydrogen as a refrigerant.

[Explanation of symbols]

 1 Liquid Nitrogen Storage Tank 2 Heat Exchanger 3 Compressor 4 Piping 5 Accumulator 6 Piping 7 Automatic Valve 8 Supply Path 9 Valve 10 Piping 11 Piping 12 Accumulator Closed Container 13 Discharge Path 14 Liquid Hydrogen Storage Tank 15 Piping 16 Expansion Valve 17 Piping 18 Evaporator 19 Piping 20 Piping 21 Cooler 22 Piping 23 Indirect refrigerant material compressor 24 Piping 25 Freezer

Claims (5)

[Claims] 1. A heat exchange container for supplying and discharging a heat transfer medium, and a plurality of circumferential flow passages provided in the heat transfer medium in the heat exchange container and arranged in parallel so as to communicate in the circumferential direction. Inlet and outlet provided in the circumferential flow passage such that the positions of the inlet and the outlet in the circumferential flow passage are displaced in the circumferential direction, and a communication flow in which the inlet and the outlet between the circumferential flow passages communicate with each other. A heat exchange flow path for a heat exchange device, and a heat exchange device having a fluid supply path and a discharge path communicating with the heat exchange flow path, a compressor, an expansion valve, and an evaporator. Low temperature generator consisting of. 2. The low temperature generator according to claim 1, further comprising a liquid hydrogen storage tank. 3. The low temperature generator according to claim 1, wherein a pressure accumulator is connected. 4. A heat transfer medium discharge pipe connected to the heat exchange container for discharging a heat transfer medium used for cooling liquid hydrogen, and a cooling device for the pressure accumulator connected to the pipe. Item 1. A low temperature generator according to item 1, 2 or 3. 5. A heat transfer medium discharge pipe connected to the heat exchange container for discharging a heat transfer medium used for cooling liquid hydrogen, and a cooling device for the liquid hydrogen storage tank connected to the pipe. The low temperature generator according to claim 1, 2, 3 or 4.