JPH05312423A - Double inlet type freezer device - Google Patents

Abstract

PURPOSE:To provide a double inlet type cryogenic freezer device utilizing a pulse tube in which an increase in temperature at a high temperature end of a cold heat accumulation device is prevented and a reduction in freezing capability is prevented. CONSTITUTION:There are provided a compressor 1. filled with gaseous refrigerant, a cold heat accumulator 4 connected to the compressor 1 through the first pipe 5 and filled with cold heat accumulation material 6, a hollow pulse tube 7 connected by a pipe to the cold heat accumulation device 4 through the second pipe 8, a low temperature extracting exchanger 9 arranged in the midway part of the second pipe 8, a buffer tank 10 connected to the pulse tube 7 through the third pipe 11, and the fourth pipe 16 connected between the first pipe 5 and the third pipe 11 through the pipe. A radiation heat exchanger 21 is arranged around a circumferential surface of the high temperature end 18 of the cold heat accumulation device 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus which uses a pulse tube to realize an extremely low temperature of 100 (-173 ° C) or lower.

[0002]

2. Description of the Related Art Conventionally, there is a refrigerating apparatus of this type shown in FIG.

In FIG. 1, reference numeral 1 denotes a compressor filled with a gaseous refrigerant, such as helium, which is in a liquid state at an extremely low temperature of 20 K or less, and a piston 3 is movably provided in a cylinder 2. Reference numeral 4 denotes a regenerator connected to the compressor 1 via a first pipe 5, and the inside thereof is filled with a regenerator material 6 such as copper or lead. 7 is this regenerator 4
Is a pulse tube connected to the second pipe 8 via a second pipe 8 and is made of stainless steel. Reference numeral 9 denotes a low-temperature extraction heat exchanger for extracting an extremely low temperature of 100 K or less, which is made of a material having high thermal conductivity such as copper and is provided in the middle of the second pipe 8. 10 is the pulse tube 7
Is a buffer tank connected via a third pipe 11, and an orifice valve 12 such as a needle valve is provided in the middle of the third pipe 11. Reference numeral 13 denotes a heat radiating heat exchanger provided at the end of the regenerator 4 on the compressor 1 side, and 14 denotes a heat radiating heat exchanger provided at the end of the pulse tube 7 on the buffer tank 10 side. Radiating fins are used. Further, copper or the like having high thermal conductivity is used as these materials.

The regenerator 4, the heat exchanger 9 for low temperature extraction, the pulse tube 7, and the second pipe 8 connecting them are vacuum chambers (vacuum degree 10 ^-4 torr or less) 1 for heat insulation.
It is stored in 5.

In the above structure, the gaseous refrigerant compressed by the compressor 1 in the compression process by the downward movement of the piston 3 of the compressor 1 in FIG. 3 is cooled while passing through the heat radiating heat exchanger 13 and the regenerator 4. The residual refrigerant in the pulse tube 7 is compressed and the residual refrigerant in the pulse tube 7 is compressed and the compression heat is radiated to the heat radiating heat exchanger 14 to flow into the buffer tank 10.

After that, during the expansion process by moving the piston 3 in the upward direction in FIG. 3, the gaseous refrigerant in the pulse tube 7 is returned and moved by sucking the gaseous refrigerant into the compressor 1 to move in the pulse tube 7. Adiabatic expansion is performed and the temperature is further lowered to cool the low temperature extraction heat exchanger 9 and the regenerator 4 and return to the compressor 1.

By repeating the reciprocating movement cycle of the gaseous refrigerant in this way, a cryogenic temperature is obtained in the low temperature take-out heat exchanger 9.

However, in this refrigerating apparatus, when the low-temperature extraction heat exchanger 9 becomes low temperature (about 100K) to some extent, the buffer tank 10 and the room temperature at the high temperature end in the pulse tube 7 are expanded during the expansion process. There is a problem that a high temperature gaseous refrigerant in the vicinity flows into the low temperature extraction heat exchanger 9 and the temperature obtained in the low temperature extraction heat exchanger 9 is limited.

As a countermeasure against this, Cryogenics, vol 30, P2
57-261, 1990, the double inlet type refrigerating apparatus shown in FIG. 2 is proposed. In this refrigeration system, the third pipe 11 between the orifice valve 12 and the heat radiating heat exchanger 14 and the first pipe 5 are newly connected by the fourth pipe 16, and the flow rate is adjusted to the intermediate portion. The orifice valve 17 is provided.

In this double inlet type refrigerating apparatus, the gaseous refrigerant compressed by the compressor 1 in the compression process by the downward movement of the piston 3 of the compressor 1 in FIG. 2 is used as a heat radiating heat exchanger 13 and a regenerator 4. And a part thereof flows into the buffer tank 10 and the heat radiating heat exchanger 14 through the fourth pipe 16 and the orifice valve 17.

At this time, the gaseous refrigerant compressed by the compressor 1 is cooled while passing through the heat radiating heat exchanger 13 and the regenerator 4 and flows into the pulse tube 7, and the residual refrigerant in the pulse tube 7 is cooled. Is compressed and its compression heat is radiated to the heat radiation heat exchanger 14, and flows into the buffer tank 10.

After that, in the expansion process by moving the piston 3 in the upward direction in FIG. 2, the gaseous refrigerant in the pulse tube 7 is moved back by moving the gaseous refrigerant in the pulse tube 7 by suctioning the gaseous refrigerant into the compressor 1. Adiabatic expansion is performed and the temperature is further lowered to cool the low temperature extraction heat exchanger 9 and the regenerator 4 and return to the compressor 1. At this time, the high temperature gaseous refrigerant near the room temperature at the high temperature end in the buffer tank 10 and the pulse tube 7 is the fourth pipe 1
6, it will be returned to the compressor 1 via the orifice valve 17.

As a result, during the expansion process, the high-temperature gaseous refrigerant near the room temperature at the high temperature end of the buffer tank 10 and the pulse tube 7 flows into the low temperature extraction heat exchanger 9 into the low temperature extraction heat exchanger 9. It was possible to prevent this from happening and to further lower the temperature of the low temperature extraction heat exchanger 9.

[0014]

However, in the above double inlet type refrigerating apparatus, in the expansion process, the high temperature gaseous refrigerant near the room temperature in the buffer tank 10 and the heat radiating heat exchanger 14 is discharged to the fourth pipe 16. , Flows into the compressor 1 and the regenerator 4 via the orifice valve 17, and as a result, the gaseous refrigerant stays at the high temperature end 18 of the regenerator 4 and raises the temperature of the high temperature end 18 of the regenerator 4. I was letting it.

Therefore, when the refrigeration system is operated for a long time, the heat of the high temperature end 18 of the regenerator 4 is transmitted to the low temperature extraction heat exchanger 9 and the obtained refrigeration temperature is about 40 to 50K. , Included new problems that reduce refrigeration capacity.

The present invention has been made in view of the above problems of the prior art, and in the above double inlet type refrigerating apparatus, the temperature rise at the high temperature end of the regenerator is prevented, and the reduction of the refrigerating capacity is prevented. The present invention provides a cryogenic refrigeration device.

[0017]

DISCLOSURE OF THE INVENTION The present invention relates to a compressor having a gaseous refrigerant filled therein, a regenerator connected to the compressor through a first pipe and filled with a regenerator material, and the regenerator. A hollow pulse tube pipe-connected to the container via a second pipe, a low temperature take-out exchanger provided in the middle of the second pipe, and a third part to the pulse tube.
A heat exchanger for radiating heat is provided on a peripheral surface of a high temperature end of the regenerator, the buffer tank being pipe-connected through a pipe, and the fourth pipe being pipe-connected between the first pipe and the third pipe. Is provided.

[0018]

According to the present invention, the heat radiating heat exchanger provided on the peripheral surface of the high temperature end of the regenerator surely radiates the heat generated at the high temperature end.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the refrigerating apparatus of the present invention will be described below with reference to FIG. The same components as those of the above-mentioned FIG. 2 device are designated by the same reference numerals.

In the figure, a water-cooling type heat-radiating heat exchanger 21 is provided on the peripheral surface of the high temperature end portion 18 of the regenerator 4.

The heat radiating heat exchanger 21, the regenerator 4, the low temperature extracting heat exchanger 9, the pulse tube 7, and the second pipe 8 connecting them are vacuum chambers (vacuum degree 10 ^-4) for heat insulation. (Torr or less) 15 is housed in the heat radiation heat exchanger 2
1, cooling water is supplied from the outside of the vacuum chamber 15.

Therefore, in the expansion process by the upward movement of the piston 3 of the compressor 1 in FIG. 1, the high-temperature gaseous refrigerant flowing from the fourth pipe 16 stays at the high-temperature end 18 of the regenerator 4 and heat is generated. Although generated, it is prevented that the temperature of the high temperature end portion 18 rises due to water cooling by the heat radiating heat exchanger 21 provided on the peripheral surface of the high temperature end portion 18.

Therefore, when the refrigeration system is operated for a long time, the heat at the high temperature end 18 of the regenerator 4 is not transferred to the low temperature extraction heat exchanger 9 and the refrigerating capacity is not lowered.

By repeating the reciprocating movement cycle of the gaseous refrigerant in this way, an extremely low temperature can be obtained in the low temperature taking-out heat exchanger 9, and as a result, the low temperature taking-out heat exchanger 9 has a temperature of 30-40K. It was confirmed that a very low temperature of

In the above embodiment, the heat radiating heat exchanger 21 is used.
Although the case where the water-cooled heat exchanger is used has been described as above, the same effect can be obtained by using an air-cooled heat exchanger in addition to this.

However, when an air-cooled heat exchanger is provided,
Only the high temperature end 18 of the regenerator 4 is provided outside the vacuum chamber 15, and an air-cooled heat exchanger is attached to the peripheral surface of the high temperature end.
It is necessary to be air-cooled by the outside air.

[0027]

As described above, according to the present invention, the heat radiating heat exchanger provided on the peripheral surface of the high temperature end of the regenerator surely radiates the heat generated at the high temperature end.

Therefore, when the refrigeration system is operated for a long time, it is possible to realize a cryogenic refrigeration system in which the temperature rise at the high temperature end of the regenerator is prevented and the refrigeration capacity is prevented from being lowered.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a double inlet type refrigerating apparatus showing an embodiment of the present invention.

FIG. 2 is a system configuration diagram of a conventional double inlet refrigeration system.

FIG. 3 is a system configuration diagram of a conventional refrigeration system.

[Explanation of symbols]

 1 Compressor 4 Regenerator 5 1st pipe 7 Pulse tube 8 2nd pipe 9 Low temperature extraction heat exchanger 10 Buffer tank 11 3rd pipe 12 Orifice valve 16 4th pipe 17 Orifice valve 18 High temperature end 21 Radiation heat exchanger

Claims (1)

[Claims] 1. A compressor having a gaseous refrigerant filled therein, a regenerator connected to the compressor through a first pipe and filled with a regenerator material, and a regenerator through a second pipe. A hollow pulse tube connected by piping, a low temperature extraction exchanger provided in the middle of the second pipe, a buffer tank connected by piping to the pulse tube via a third pipe, the first pipe, And a fourth pipe connected between the third pipe and a third pipe, and a heat radiating heat exchanger is provided on the peripheral surface of the high temperature end of the regenerator.