JPH09324958A - Cryogenic temperature refrigerating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cryogenic temperature refrigerating machine capable of using the compressor of a low flow rate. SOLUTION: A compressor unit 1 is connected to a cold generating unit 2 through a passage selector valve 12. The passage selector valve 12 is formed with a four-way valve. The first port 14 of the passage selector valve 12 formed with the four-way valve is connected to and communicates with the high pressure gas passage 5 of the compressor unit 1, a second port 15 is connected to and communicates with the low pressure gas passage 11 of the compressor unit 1, a third port 16 is connected and communicates with the cold generating unit 2 and a fourth port 17 is connected and communicate with a buffer tank 18, respectively. The cold generating unit 2 selectively communicates with the high pressure gas passage 5 of the compressor unit 1, the low pressure gas passage 11 or the buffer tank 18 in accordance with the switching operation of the passage selector valve 12.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a cryogenic refrigerator using gas as a refrigerant.

[0002]

2. Description of the Related Art Conventionally, in a cryogenic refrigerator using gas as a working fluid, as shown in FIG.
(50) and the cold generation unit (51) are connected via a flow path switching valve (52) constituted by a rotary valve, and the cold generation unit (51) is compressed by a switching operation of the flow path switching valve (52). Unit (50)
And a state in which the cold generation unit (51) communicates with the low pressure gas passage (54) of the compressor unit (50).

[0003]

However, in the conventional cryogenic refrigerator, the cold generation unit (51) is provided with a flow path switching valve.
(52) is connected to the high pressure gas passage (53) and the low pressure gas passage (54) of the compressor unit (52). Since a large amount of gas enters and exits when suctioning high-pressure gas from the generating unit (51), there is a problem that a compressor having a large flow rate must be used even with a compressor having the same discharge pressure. It is an object of the present invention to provide a cryogenic refrigerator capable of using a compressor with a small flow rate, focusing on such a point.

[0004]

In order to achieve the above object, according to the present invention, a buffer tank is disposed so as to be able to communicate with a cold generation unit, and gas supply / discharge to / from this buffer tank is switched by a switching operation of a flow path switching valve. In this case, the working fluid (refrigerant gas) is stored in the buffer tank at an intermediate pressure between the discharge pressure of the compressor and the return pressure to the compressor.

[0005]

According to the present invention, the buffer tank is arranged so as to be able to communicate with the cold generation unit, and the supply and discharge of gas to and from this buffer tank are performed in conjunction with the switching operation of the flow path switching valve. When the flow path switching valve is positioned so as not to communicate with any of the gas passages, the cold generation unit and the buffer tank are communicated. Thus, the working fluid (refrigerant gas) can be stored in the buffer tank at an intermediate pressure between the discharge pressure of the compressor and the return pressure to the compressor. Then, before the cold generation unit communicates with the compressor unit, the gas stored in the buffer tank flows into the cold generation unit to raise the inside of the cold generation unit to an intermediate pressure. The cold generating unit in the state of the intermediate pressure communicates with the high pressure gas passage of the compressor unit, and the pressure is increased to the discharge pressure of the compressor. Next, the buffer tank and the cold generating unit communicate with each other in a state where the communication between the cold generating unit and the high-pressure gas passage is interrupted, and the pressure gas in the cold generating unit flows into the buffer tank, and Is reduced to an intermediate pressure. Next, the cold generation unit and the low-pressure gas passage of the compressor unit communicate with each other, and the working gas in the cold generation unit is sucked by the compressor.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention, and FIG. 2 is a conceptual diagram thereof.
(1) is a compressor unit, (2) is a cold generating unit composed of a piston elevating cold head, and the compressor unit (1) and the cold generating unit (2) are connected via a valve unit (3). Connected.

The compressor unit (1) includes a cooler (6), an oil separator (7), and an oil adsorber (8) connected in series to a high-pressure gas passage (5) derived from a discharge port of the compressor (4). And a bypass passage (9) branching out from between the oil separator (7) and the oil adsorber (8) is connected to the suction port of the compressor (4) through the pressure regulating valve (10). Connected to the low pressure gas passage (11).

The valve unit (3) comprises a flow path switching valve (12) formed of a rotary type four-way valve and an electric motor (13) for driving the flow path switching valve (12). The first port (14) of the switching valve (12) is connected to the high-pressure gas passage of the compressor unit (1).
In (5), the second port (15) is connected to the low-pressure gas passage (11) of the compressor unit (1), and the third port (16) is connected to the cold generation unit (2).
The fourth port (17) is connected to the buffer tank (18).

The passage switching valve (12) is connected to a high-pressure gas passage (5) by the rotation of a rotor (not shown).
(2), the buffer tank (18) communicates with the cold generating unit (2), the low-pressure gas passage (11) communicates with the cold generating unit (2), the buffer tank (18) cools The four states of communicating with the generating unit (2) are sequentially repeated.

FIG. 3 shows a conceptual diagram of another embodiment of the present invention, in which the flow path switching valve (12) is constituted by a rotary three-way valve, and the first port of the flow path switching valve (12) is provided. (14) is a high pressure gas passage (5) of the compressor unit (1), a second port (15) is a low pressure gas passage (11) of the compressor unit (1), and a third port (16) is a cold generation unit. (2)
The buffer tank (1) is connected to a refrigerant gas passage (19) connecting the flow path switching valve (12) and the cold generation unit (2) via an on-off valve (20).
8), and the on-off valve (20) is configured to open and close in conjunction with the operation of the flow path switching valve (12). Operation unit generates cold
(2) High or low pressure gas passage of the compressor unit (1)
(5) The valve is opened without communicating with (11), and the cold generation unit (2) is in communication with either the high or low pressure gas passage (5) (11) of the compressor unit (1). Is configured to close.

In the cryogenic refrigerator configured as described above,
When the cold generating unit (2) and the compressor unit (1) are in communication, the buffer tank (18) and the cold generating unit (2)
When the cold generation unit (2) and the compressor unit (1) are not in communication, the buffer tank (1) is disconnected.
8) and the cold generation unit (2) are electrically connected to each other, so that the working fluid flows into the buffer tank (18) at an intermediate pressure between the discharge pressure of the compressor (4) and the return pressure to the compressor (4). (Refrigerant gas) is enclosed or the working fluid of the intermediate pressure is supplied to the cold generation unit (2).
The amount of working fluid that passes through the
(4) The pressure fluctuation width in the cold generation unit (2) can be made large.

FIGS. 4 to 6 show a case where a pulse tube type cold head is used as the cold generation unit (2),
This cold generation unit (2) comprises a regenerator (21) and a pulse tube (2).
2) and a heat absorbing connecting path (23) connecting the regenerator (21) and the pulse tube (22).

4 and 5, the flow path switching valve (12) arranged in the connection path between the compressor unit (1) and the cold generation unit (2) is constituted by a rotary five-way valve. Flow path switching valve
The first port (14) of (12) is connected to the high-pressure gas passage (5) of the compressor unit (1), the second port (15) is connected to the low-pressure gas passage (11) of the compressor unit (1), and the third port is connected to the third port. Port (16) for cold generation unit
Connect the fourth port (17) to the buffer tank in the regenerator (21) of (2).
In (18), the fifth port (24) is connected to each of the pulse tubes (22).

The flow path switching valve (12) is in a state in which the high pressure gas passage (5) communicates with the regenerator (21) by rotation of a rotor (not shown), and the buffer tank (18) is connected to the pulse tube (22). Communicating, the low-pressure gas passage (11) communicating with the regenerator (21),
4 when the buffer tank (18) is in communication with the pulse tube (22)
The two states are sequentially repeated.

FIG. 6 shows a conceptual diagram of another embodiment, in which the flow path switching valve (12) is constituted by a rotary three-way valve, and the first port (14) of the flow path switching valve (12) is provided. ) The compressor unit
The second port (15) is connected to the high-pressure gas passage (5) of (1), the third port (16) is connected to the low-pressure gas passage (11) of the compressor unit (1), and the regenerator (2) of the cold generation unit (2). And the buffer tank (18) is connected to the high-temperature end of the pulse tube (22) of the cold generation unit (2) via the on-off valve (20), and the on-off valve (20) is connected. The on-off valve (20) is configured to open and close in conjunction with the operation of the flow path switching valve (12).
The valve is opened without being connected to either the high or low pressure gas passage (5) or (11) of (1), and the cold generation unit (2) is connected to either the high or low pressure gas passage of the compressor unit (1). 5) It is configured to close the valve when it is in communication with (11).

[0016]

According to the present invention, the buffer tank is arranged so as to be able to communicate with the cold generation unit, and the supply and discharge of gas to and from this buffer tank are performed in conjunction with the switching operation of the flow path switching valve. Since the configuration is such that the cold generation unit and the buffer tank are communicated only in a state that does not communicate with any of the gas passages of the unit, the intermediate pressure between the discharge pressure of the compressor and the return pressure to the compressor in the buffer tank. The working fluid (refrigerant gas) can be stored under pressure. As a result, the gas stored in the buffer tank flows into the cold generation unit before the cold generation unit communicates with the compressor unit, raises the cold generation unit to an intermediate pressure, and in the intermediate pressure state. Since the cold generation unit of is communicated with the high pressure gas passage of the compressor unit and the pressure is increased to the discharge pressure of the compressor, the pressure in the cold generation unit is reduced within a short time after switching the flow path switching valve. A predetermined high pressure state can be achieved.

After the internal pressure of the cold generating unit becomes high, the communication between the cold generating unit and the high-pressure gas passage is cut off. The pressure gas in the generating unit flows into the buffer tank, the pressure in the cold generating unit is reduced to the intermediate pressure, and then the cold generating unit communicates with the low-pressure gas passage of the compressor unit to operate the cold generating unit. The gas is sucked by the compressor, and the inside of the cold generation unit becomes a predetermined low pressure state.In this case, too, the pressure difference between the pressure (intermediate pressure) in the cold generation unit and the suction pressure of the compressor is small. The inside of the cold generation unit can be brought into a predetermined low pressure state in a short time.

As a result, the capacity of the compressor constituting the cryogenic refrigerator can be reduced, the pressure switching cycle in the cold generation unit can be shortened, and the performance of the refrigerator can be improved. be able to.

Further, when the flow path switching valve is constituted by a rotary valve, it is possible to easily control the switching between the cold generating unit and the compressor unit and the switching between the cold generating unit and the buffer tank. .

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment.

FIG. 2 is a conceptual diagram thereof.

FIG. 3 is a conceptual diagram showing a different embodiment.

FIG. 4 is a schematic configuration diagram showing another embodiment.

FIG. 5 is a conceptual diagram thereof.

FIG. 6 is a conceptual diagram showing a different embodiment.

FIG. 7 is a conceptual diagram of a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Compressor unit, 2 ... Cold generation unit, 5 ... High pressure gas passage, 11 ... Low pressure gas passage, 12 ... Flow switching valve, 14 ... First port of flow switching valve, 15 ... Flow switching valve 2 ports,
16: third port of the flow path switching valve, 17: fourth port of the flow path switching valve, 18: buffer tank, 19: refrigerant gas passage, 20: open / close valve, 21: regenerator, 22: pulse tube, 23 ... Endothermic connection path,
24… Fifth port of the flow path switching valve.

Claims (8)

[Claims] 1. Compressor unit (1) and cold generation unit
(2) is connected via a flow path switching valve (12), and the switching operation of the flow path switching valve (12) causes the cold generation unit (2) to be connected to the high pressure gas passage (5) of the compressor unit (1). And the cold generation unit (2) is connected to the low pressure gas passage (1) of the compressor unit (1).
In a cryogenic refrigerator configured to switch to the state of communicating with (1), the flow path switching valve (12) is a four-way valve, and the flow path switching valve (12) with a four-way valve 1 port (14) to the high pressure gas passage (5) of the compressor unit (1), 2nd port (15) to the compressor unit
In the low-pressure gas passage (11) of (1), the third port (16) is connected to the cold generation unit (2), and the fourth port (17) is connected to the buffer tank (18).
The cold generating unit (2) is connected to the high pressure gas passage (5), the low pressure gas passage (11) and the buffer tank (1) of the compressor unit (1) by the switching operation of the flow path switching valve (12).
8) A cryogenic refrigerator characterized in that the cryogenic refrigerator is configured to selectively communicate with 8). 2. The cryogenic refrigerator according to claim 1, wherein the flow path switching valve (12) is constituted by a rotary valve. 3. A compressor unit (1) and a cold generation unit
(2) is connected via a flow path switching valve (12), and the switching operation of the flow path switching valve (12) causes the cold generation unit (2) to be connected to the high pressure gas passage (5) of the compressor unit (1). And the cold generation unit (2) is connected to the low pressure gas passage (1) of the compressor unit (1).
In a cryogenic refrigerator configured to be able to switch to a state communicating with (1), a buffer tank (19) is connected to a refrigerant gas passage (19) connecting the flow path switching valve (12) and the cold generation unit (2). 18) is branched and connected via an on-off valve (20), and this on-off valve (20) is connected to the flow path switching valve (12).
By opening and closing in conjunction with the switching operation of the compressor, the cold generation unit (2) is connected to the high pressure gas passage of the compressor unit (1).
(5), the cold generating unit (2) is in communication with the low pressure gas passage (11) of the compressor unit (1), and the cold generating unit (2) is in communication with the buffer tank (18). A cryogenic refrigerator characterized by being switched to a state. 4. The cryogenic refrigerator according to claim 3, wherein the flow path switching valve (12) and the on-off valve (20) are each constituted by a rotary valve. 5. A compressor unit (1) and a cold generation unit
(2) is connected via a flow path switching valve (12), and the switching operation of the flow path switching valve (12) causes the cold generation unit (2) to be connected to the high pressure gas passage (5) of the compressor unit (1). And the cold generation unit (2) is connected to the low pressure gas passage (1) of the compressor unit (1).
In the cryogenic refrigerator configured to be switched to the state communicating with 1), cold is generated by connecting the regenerator (21) and the pulse tube (22) via the heat absorption connection path (23). Unit (2) comprising a flow path switching valve
The first port (14) of (12) is connected to the high-pressure gas passage (5) of the compressor unit (1), the second port (15) is connected to the low-pressure gas passage (11) of the compressor unit (1), and the third port is connected to the third port. Port (16) for cold generation unit
Connect the fourth port (17) to the buffer tank in the regenerator (21) of (2).
(18), the fifth port (24) is connected to the pulse tube (22), respectively, and the operation of the flow path switching valve (12) causes the cold generation unit (2) to operate.
The regenerator (21) of the compressor is the high pressure gas passage (5) of the compressor unit (1).
To the low pressure gas passage (11) of the compressor unit (1), the pulse tube (22) of the cold generation unit (2) is a buffer. A cryogenic refrigerator characterized in that it is configured to selectively switch the state of communication with the tank (18). 6. The cryogenic refrigerator according to claim 5, wherein the flow path switching valve (12) is constituted by a rotary valve. 7. A compressor unit (1) and a cold generation unit
(2) is connected via a flow path switching valve (12), and the switching operation of the flow path switching valve (12) causes the cold generation unit (2) to be connected to the high pressure gas passage (5) of the compressor unit (1). And the cold generation unit (2) is connected to the low pressure gas passage (1) of the compressor unit (1).
In the cryogenic refrigerator configured to be switched to the state communicating with 1), cold is generated by connecting the regenerator (21) and the pulse tube (22) via the heat absorption connection path (23). Unit (2) comprising a flow path switching valve
(12) is connected to the regenerator (21) and the pulse tube (2
A buffer tank (18) is connected to the high-temperature end of 2) through an on-off valve (25), and the on-off valve (25) is opened and closed in conjunction with the switching operation of the flow path switching valve (12). By regenerator
A state where (21) communicates with the high pressure gas passage (5) of the compressor unit (1), a state where the regenerator (21) communicates with the low pressure gas passage (11) of the compressor unit (1), and a pulse tube A cryogenic refrigerator characterized in that (22) is switched to a state of communicating with the buffer tank (18). 8. The cryogenic refrigerator according to claim 7, wherein each of the flow path switching valve (12) and the on-off valve (20) is constituted by a rotary valve.