JPH10132402A - Helium compression device - Google Patents

Abstract

(57) Abstract: A helium gas compressed by a compressor 11 is cooled through a heat exchanger 12, and then is passed through an oil separator 13 that separates gas and oil from the main body 90 of the cryogenic refrigerator. A helium compression device that feeds in and returns the helium gas that has flowed out of the return path of the main body 90 to the suction side of the compressor 11, which prevents oil from accumulating in the helium gas pipeline 22 inside the heat exchanger 12 during operation stop. And a device that can start operation smoothly upon restart. SOLUTION: A helium gas inlet 13a provided at an upper part of an oil separator 13 is disposed below a helium gas outlet 12b provided at a lower part of the heat exchanger 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a helium compression device. More specifically, the present invention relates to a helium compression device for sending helium gas into a cryogenic refrigerator.

[0002]

2. Description of the Related Art As shown in FIG. 4, a cryogenic refrigerator has a helium gas connected to the refrigerator main body 90 via a forward pipe 127 and a return pipe 128 in order to feed helium gas into the refrigerator main body 90. It often has a compression device 100. Note that reference numerals 118 and 119 indicate joints. The helium gas (including oil, moisture, etc.) compressed by the compressor 111 is cooled by the heat exchanger 112, and passes through an oil separator 113, which separates gas and oil, and an adsorber 114, which adsorbs moisture and the like. , 22kgf / cm through outgoing pipe 127
^It is sent to the refrigerator main body 90 in about ^two . Refrigerator body 9
Inside zero, the helium gas is cooled by several stages of isothermal compression and adiabatic expansion. In the return path inside the refrigerator main body 90, the temperature is raised by performing heat exchange with the helium gas on the outward path,
It returns to kgf / cm ² and returns to the helium compression device 100 through the return line 128. Then, the gas enters the compressor 111 from the suction side 111b through the pipe 129, the accumulator 115, and the pipe 130, and is compressed again. The discharge-side pipe 121 of the compressor 111 exits the discharge port 111a provided at the upper part of the compressor 111, and then falls downward on the way to the helium gas inlet 112a provided at the upper part of the heat exchanger 112.
It is connected to the. The helium gas outlet 112b provided at the lower part of the heat exchanger 112 and the helium gas inlet 113a provided at the upper part of the oil separator 113 are connected horizontally by a pipe 123. The gas outlet side pipe 125 of the oil separator 113 once rises upward from the gas outlet 113b,
It is bent in the middle and extends downward, and is connected to a gas inlet 114 a provided at a lower part of the adsorber 114. Adsorber 11
The gas outlet 114b provided at the upper part of the fourth and the joint 118 are directly connected horizontally by a pipe 126. With such an arrangement, the oil discharged from the compressor 111 during operation is discharged from the compressor 111 on the discharge side pipe 121, the coiled helium gas pipe 122 inside the heat exchanger 112, and the helium gas outlet side of the heat exchanger 112. Oil separator 113 through pipe 123
Oil outlet 1 provided in the lower part of the oil separator 113
From 13c, the oil returns to the oil return port 111c of the compressor 111 through an oil return pipe 124 through a filter 116 and an orifice 117 provided below the filter 13c. In addition, the compressor 1
The ratio of the amount of oil existing in the oil separator 11, the oil separator 113, and the oil return pipe 124 is set to a constant ratio, for example, 6: 3: 1. The main reason for using oil in this way is that helium gas is a monatomic gas and has a specific heat ratio κ (constant pressure specific heat c _p
And since the ratio of the constant volume specific heat _{c v (c p / c v} )) is large, the heat generation is large at the time of compression, because the compressor 111 is large must be cooled.

[0003]

However, when the conventional helium compression device 100 is shut down for a long period of time, especially when the ambient temperature is low such as in winter, the helium gas line 122 inside the heat exchanger 112 is oiled. There is a problem that accumulates. For this reason, the oil amount may not be balanced at the time of restart, and an operation failure may occur.

Accordingly, an object of the present invention is to provide a helium compression device capable of preventing oil from accumulating in a helium gas pipe inside a heat exchanger during operation stop and smoothly starting operation at restart. It is in. The object of the present invention is to
It is an object of the present invention to provide a helium compression device that can start operation smoothly upon restart even if oil is accumulated in a helium gas pipeline inside a heat exchanger during operation stop.

[0005]

In order to achieve the above object, a helium compression apparatus according to claim 1 separates gas and oil after cooling helium gas compressed by a compressor through a heat exchanger. In a helium compression device which feeds the helium gas flowing out of the return path of the main body of the cryogenic refrigerator to the outward path of the main body of the cryogenic refrigerator through the oil separator, The helium gas inlet provided above the oil separator is located below the gas outlet.

In the helium compression device according to the first aspect, the helium gas inlet provided at the upper part of the oil separator is disposed below the helium gas outlet provided at the lower part of the heat exchanger. During shutdown, the oil in the helium gas line inside the heat exchanger moves from the heat exchanger side to the oil separator by gravity. Therefore, when the operation is stopped for a long period of time, especially when the ambient temperature is low such as in winter, the accumulation of oil in the helium gas pipeline inside the heat exchanger is prevented. As a result, the operation can be started smoothly at the time of restart, and the reliability of the entire system is improved.

In the helium compression device according to the second aspect, after the helium gas compressed by the compressor is cooled through the heat exchanger, the helium gas passes through the oil separator that separates the gas and the oil, and the outward passage of the main body of the cryogenic refrigerator. In the helium compression device, which returns the helium gas that has flowed out of the return path of the main body to the suction side of the compressor, an oil return provided in the compressor from a helium gas outlet provided in a lower portion of the heat exchanger. A port is disposed below, and between the helium gas outlet of the heat exchanger and the oil return port of the compressor, an oil return channel in which a valve is inserted is provided. I do.

In the helium compression device according to the second aspect of the invention, the valve in the helium gas line inside the heat exchanger is returned from the heat exchanger side by gravity due to gravity by keeping the valve open during operation stop. It moves to the oil return port of the compressor through the flow path. Therefore, when the operation is stopped for a long period of time, especially when the ambient temperature is low such as in winter, the accumulation of oil in the helium gas pipeline inside the heat exchanger is prevented. As a result, the operation can be started smoothly at the time of restart, and the reliability of the entire system is improved. The above valve is
During operation of the device, it is closed.

According to a third aspect of the present invention, in the helium compression apparatus according to the second aspect, the oil return port of the compressor is formed above an oil reservoir of the compressor. And

In the helium compression device according to the third aspect, the oil return port is formed above the oil reservoir.
During operation stoppage, the oil returned from the heat exchanger through the oil return passage easily enters the oil reservoir from the oil return port. Therefore, at the time of restart, the compressor operates immediately and smoothly.

According to a fourth aspect of the present invention, in the helium compression device, the helium gas compressed by the compressor is cooled through a heat exchanger, and then is passed through an oil separator for separating gas and oil. In a helium compression device that returns helium gas that has flowed out of the return path of the main body to the suction side of the compressor, a main flow path that connects the helium gas outlet of the heat exchanger and the helium gas inlet of the oil separator, A three-way valve capable of forming a bypass flow path between the helium gas outlet of the heat exchanger and the oil return port of the compressor by interrupting the main flow path is interposed.

In the helium compression device according to the fourth aspect, when the operation is stopped and restarted, the helium compression device temporarily (for example, only for a few seconds)
The three-way valve is switched to shut off the main flow path and form a bypass flow path connecting the helium gas outlet of the heat exchanger and the oil return port of the compressor. This allows
Even if oil is accumulated in the helium gas line inside the heat exchanger during operation stop, the oil is forced by the operation of the compressor together with the helium gas from the heat exchanger side to the compressor side through the bypass flow path. Is returned. Subsequently, the three-way valve is switched to shut off the bypass flow path and open the main flow path, and the original operation is started. In this way, when restarting, the oil is forcibly returned to the oil sump of the compressor regardless of the height difference of the compressor, heat exchanger, and oil separator, so the helium gas pipeline inside the heat exchanger during operation stop Even if oil accumulates, the operation is started smoothly at restart. As a result, the reliability of the entire system increases.

[0013]

Embodiments of the present invention will be described below in detail.

FIG. 1 shows a helium compression device 1 according to a first embodiment.
1 shows a schematic arrangement of a cryogenic refrigerator with zeros when viewed from the side. The helium compression device 10 is provided with an outgoing pipe 2
7, connected to the refrigerator main body 90 via the return pipe 28. Reference numerals 18 and 19 indicate joints.

The helium compression device 10 is similar to the conventional helium compression device 100 shown in FIG.
, Heat exchanger 12, and oil separator 1 for separating gas and oil
3 and an adsorber 14 for adsorbing moisture and the like. The helium gas (including oil and moisture) compressed by the compressor 11 is cooled by the heat exchanger 12, passes through the oil separator 13 and the adsorber 14 in order, and passes through the outgoing pipe 27.
It is fed into the refrigerator main body 90 at about 2 kgf / cm ² . Inside the refrigerator main body 90, the temperature of the helium gas is lowered by several stages of isothermal compression and adiabatic expansion. The refrigerator main body 90
The temperature is increased by performing heat exchange with the helium gas on the outward path in the internal return path, and is returned to the helium compression device 10 through the return pipe 28 at 9 kgf / cm ² . Then, the air enters the compressor 11 from the suction side 11b through the pipe 29, the accumulator 15, and the pipe 30, and is compressed again.

The helium compression device 10 has a heat exchanger 1 compared to the conventional helium compression device 100 shown in FIG.
2 are located above. As a result, the helium gas inlet 12a provided above the heat exchanger 12 is disposed above the discharge port 11a provided above the compressor 11. Further, a helium gas inlet 13a provided above the oil separator 13 is disposed below a helium gas outlet 12b provided below the heat exchanger 12. Accordingly, the discharge-side pipe 21 of the compressor 11 is
After leaving the discharge port 11a provided at the upper part of the heat exchanger 12, it rises on the way and is connected to the helium gas inlet 12a provided at the upper part of the heat exchanger 12. The helium gas outlet-side pipe 23 of the heat exchanger 12 exits the helium gas outlet 12b and then goes down on the way to be connected to the helium gas inlet 13a provided at the upper part of the oil separator 13. The gas outlet side pipe 25 of the oil separator 13 rises once from the gas outlet 13b, bends in the middle and extends downward, and is connected to a gas inlet 14a provided at a lower part of the adsorber 14. Gas outlet 14b provided above adsorber 14
And the joint 18 are directly connected horizontally by a pipe 26.

With such an arrangement, oil discharged from the compressor 11 during operation is discharged from the discharge-side pipe 21 of the compressor 11,
A coiled helium gas line 22 inside the heat exchanger 12,
The oil accumulates in the oil separator 13 through the helium gas outlet pipe 23 of the heat exchanger 12, and is returned from the oil outlet 13c provided at the lower part of the oil separator 13 via the filter 16 and the orifice 17 provided therebelow. To the oil return port 11c of the compressor 11 through the use pipe 24.

The helium gas inlet 13a provided above the oil separator 13 is located below the helium gas outlet 12b provided below the heat exchanger 12. Oil in the helium gas pipeline 22 inside the exchanger 12 moves from the heat exchanger 12 side to the oil separator 13 through the pipe 23 by gravity. Therefore, when the operation is stopped for a long period of time, especially when the ambient temperature is low such as in winter, it is possible to prevent the accumulation of oil in the helium gas pipeline 22 inside the heat exchanger 12. As a result, the operation can be started smoothly at the time of restart, and the reliability of the entire system can be improved.

FIG. 2 shows a helium compression device 4 according to a second embodiment.
1 shows a schematic arrangement of a cryogenic refrigerator with zeros when viewed from the side. The helium compression device 40 is provided with an outgoing pipe 2
7, connected to the refrigerator main body 90 via the return pipe 28. The same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

In the helium compression device 40, in addition to the oil return port 11c described above, an oil return port 11d is formed at a position corresponding to the upper part of the oil reservoir (provided inside the compressor) of the compressor 11. Have been. This oil return port 11d is provided with a helium gas outlet 12b provided at the lower part of the heat exchanger 12.
Lower than the gas inlet 13a of the oil separator 13.
At the same height level as. Further, a pipe 31 extending vertically downward from the vicinity of the helium gas outlet 12b in the helium gas outlet side pipe 23 of the heat exchanger 12 is branched. The vertical pipe 31 is connected to a pipe 32 that is connected to the oil return port 11d of the compressor 11 and extends horizontally. The helium gas outlet 12b of the heat exchanger 12 and the oil return port 11d of the compressor 11 are formed by the vertical pipe 31 and the horizontal pipe 32.
And an oil return flow path is formed between them. Horizontal piping 32
An electromagnetic valve 35 capable of opening and closing the oil return flow path is interposed in the valve. The end of the horizontal pipe 32 on the side of the vertical pipe 31 and the gas inlet 13a of the oil separator 13 are connected by a horizontal pipe 33 in which a solenoid valve 36 is inserted.

During operation, the solenoid valves 35 and 36 are closed. Thus, the helium compression device 40 operates in exactly the same manner as the helium compression device 10 shown in FIG. That is, the helium gas (including oil, moisture, and the like) compressed by the compressor 11 is cooled by the heat exchanger 12, passes through the oil separator 13 and the adsorber 14 in order, and passes through the outgoing pipe 27 to the refrigerator main body 90. It is sent and returned to the helium compression device 10 through the return line 28. Then, the air enters the compressor 11 from the suction side 11b through the pipe 29, the accumulator 15, and the pipe 30, and is compressed again.

When the operation is stopped, the solenoid valve 35 is opened (the solenoid valve 36 will be described later, but is normally closed). Helium gas line 2 inside heat exchanger 12
The oil of No. 2 is moved from the heat exchanger 12 side by gravity to the vertical pipe 3
1. It moves to the compressor 11 side through the horizontal pipe 32. Since the oil return port 11d is formed above the oil reservoir of the compressor 11, the returned oil easily enters the oil reservoir through the oil return port 11d. Therefore, when the operation is stopped for a long period of time, especially when the ambient temperature is low such as in winter, it is possible to prevent the accumulation of oil in the helium gas pipeline 22 inside the heat exchanger 12. As a result, the operation can be started smoothly immediately upon restart, and the reliability of the entire system can be improved.

By setting the solenoid valve 35 and the solenoid valve 36 to an open state when the operation is stopped, the helium gas is removed from the oil separator 13 while the refrigerator main body 90 is not operated.
A path for returning from the compressor to the compressor 11 can be formed.

FIG. 3 shows a helium compression device 5 according to a third embodiment.
1 shows a schematic arrangement of a cryogenic refrigerator with zeros when viewed from the side. The helium compression device 50 is provided with an outgoing pipe 2
7, connected to the refrigerator main body 90 via the return pipe 28. The same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

In the helium compression device 50, a pipe 23 forming a main flow path connecting the helium gas outlet 12 b of the heat exchanger 12 and the helium gas inlet 13 a of the oil separator 13 is
A three-way valve 37 is inserted. Two of the three ports of the three-way valve 37 are connected to the pipes 23 on both sides. The remaining one port of the three-way valve 37 and the compressor 1
A pipe 34 forming a bypass flow path is provided between the first oil return port 11d. Note that the oil return port 11d is formed at a position corresponding to an upper portion of an oil reservoir (provided inside the compressor) of the compressor 11.

During operation, the three-way valve 37 is set to a switching position in which the pipe 23 is opened to allow the main flow path to flow, and the port on the pipe 34 side is closed. Thereby, the helium compression device 40 is connected to the helium compression device 10 shown in FIG.
Works exactly the same as That is, the helium gas (including oil, moisture, and the like) compressed by the compressor 11 is cooled by the heat exchanger 12, and is cooled by the oil separator 13 and the adsorber 14.
Through the outgoing pipe 27 to the refrigerator main body 90, and the helium compression device 10 through the return pipe 28.
Is returned to. And the pipe 29, the accumulator 15,
It enters the compressor 11 from the suction side 11b through the pipe 30,
It is compressed again.

When the operation is stopped, the three-way valve 37 is set to the switching position in which the pipe 23 is opened to allow the main flow path to flow, and the port on the pipe 34 side is closed.

At the time of restart after the operation is stopped, the three-way valve 37 shuts off the port on the downstream side of the pipe 23 temporarily (for example, only for a few seconds) to allow the upstream side of the pipe 23 to flow through the pipe 34. The switching position is set. As a result, the helium gas outlet 12b of the heat exchanger 12 is temporarily connected to the compressor 1
A bypass flow passage is formed between the first oil return port 11d. In this case, even if oil is accumulated in the helium gas pipeline 22 inside the heat exchanger 12 during the stop of operation, the oil is bypassed from the heat exchanger 12 side together with the helium gas by the operation of the compressor 11. The gas is forcibly returned to the compressor 11 through the flow path, specifically, a part of the pipe 23 upstream of the three-way valve 37 and the pipe 34. Subsequently, the three-way valve 37 is set to a switching position where the pipe 23 is opened to allow the main flow path to flow, and the port on the pipe 34 side is closed. Thereby, the original operation is started.

As described above, when the compressor is restarted, the oil is forcibly returned to the oil sump of the compressor 11 regardless of the height difference between the compressor 11, the heat exchanger 12, and the oil separator 13. Even if oil is accumulated in the helium gas pipeline 22 inside the vessel 12, the operation can be started smoothly at the time of restart. As a result, the reliability of the entire system can be improved.

In the helium gas compression device 50, like the helium gas compression device 10 shown in FIG.
Helium gas outlet 12 provided below heat exchanger 12
Since the helium gas inlet 13a provided above the oil separator 13 is disposed below the b, the oil in the helium gas pipe 22 inside the heat exchanger 12 passes through the pipe 23 by gravity during operation stop. It moves to the oil separator 13 from the heat exchanger 12 side. Therefore, the reliability of the entire system can be further improved.

[0031]

As is clear from the above, in the helium compression device according to the first aspect, the helium gas inlet provided at the upper part of the oil separator is lower than the helium gas outlet provided at the lower part of the heat exchanger. During operation shutdown, oil in the helium gas pipeline inside the heat exchanger moves from the heat exchanger side to the oil separator by gravity. Therefore,
When the operation is stopped for a long period of time, especially when the ambient temperature is low such as in winter, it is possible to prevent the accumulation of oil in the helium gas pipeline inside the heat exchanger. As a result,
The operation can be started smoothly at the time of restart, and the reliability of the entire system can be improved.

[0032] In the helium compression device according to the second aspect, the oil return port provided in the compressor is disposed below the helium gas outlet provided in the lower part of the heat exchanger, and the helium of the heat exchanger is provided. Since an oil return flow path in which a valve is interposed is provided between the gas outlet and the oil return port of the compressor, the valve is kept open during operation stop, so The oil in the helium gas pipeline inside the exchanger moves from the heat exchanger side to the oil return port of the compressor through the oil return channel due to gravity. Therefore, when the operation is stopped for a long period of time, especially when the ambient temperature is low such as in winter, it is possible to prevent the accumulation of oil in the helium gas pipeline inside the heat exchanger. As a result, the operation can be started smoothly at the time of restart, and the reliability of the entire system can be improved.

In the helium compression device according to the third aspect,
Since the oil return port of the compressor is formed above the oil sump of the compressor, the oil returned from the heat exchanger side through the oil return flow path during the operation stop is discharged from the oil return port through the oil return port. Easily enters the sump. Therefore, at the time of restart, the compressor operates immediately and smoothly.

According to a fourth aspect of the present invention, in the helium compression device, a helium gas outlet of the heat exchanger is connected to a helium gas inlet of the oil separator, and the helium gas outlet of the heat exchanger is cut off. Since a three-way valve capable of forming a bypass flow path is interposed between the outlet and the oil return port of the compressor, when the operation is stopped and restarted, the three-way valve is temporarily (for example, only several seconds). Shut off the main flow path with a three-way valve,
By switching so as to form a bypass flow path connecting the helium gas outlet of the heat exchanger and the oil return port of the compressor, the oil is forcibly applied regardless of the height difference between the compressor, the heat exchanger, and the oil separator. Can be returned to the compressor sump. Therefore, even if oil accumulates in the helium gas pipeline inside the heat exchanger during operation stop, operation can be started smoothly at restart. As a result, the reliability of the entire system can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic arrangement of a cryogenic refrigerator including a helium compression device according to a first embodiment of the present invention when viewed from a side.

FIG. 2 is a diagram showing a schematic arrangement of a cryogenic refrigerator including a helium compression device according to a second embodiment of the present invention when viewed from the side.

FIG. 3 is a diagram showing a schematic arrangement of a cryogenic refrigerator including a helium compression device according to a third embodiment of the present invention when viewed from the side.

FIG. 4 is a diagram showing a schematic arrangement of a cryogenic refrigerator equipped with a conventional helium compression device when viewed from the side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Compressor 12 Heat exchanger 13 Oil separator 10, 40, 50 Helium compressor 90 Refrigerator main body

Claims (4)

[Claims] The helium gas compressed by a compressor (11) is cooled through a heat exchanger (12) and then passed through an oil separator (13) for separating gas and oil. ) And sent to the main body (90)
In the helium compression device for returning the helium gas flowing out of the return path to the suction side of the compressor (11), the helium gas outlet (12b) provided at the lower part of the heat exchanger (12) is connected to the oil separator ( A helium compression device, characterized in that a helium gas inlet (13a) provided at the upper part of (13) is arranged below. 2. The helium gas compressed by the compressor (11) is cooled through a heat exchanger (12) and then passed through an oil separator (13) for separating gas and oil. ) And sent to the main body (90)
In the helium compression device for returning the helium gas flowing out of the return path to the suction side of the compressor (11), the helium gas outlet (12b) provided at the lower part of the heat exchanger (12) is connected to the compressor (11). ) Is provided below, and the helium gas outlet (12) of the heat exchanger (12) is disposed below the oil return port (11d).
b) and the oil return port (11d) of the compressor (11), the oil return flow path (31,
32) A helium compression device characterized by comprising: 3. The helium compression device according to claim 2, wherein the oil return port (11d) of the compressor (11) is formed above an oil reservoir of the compressor (11). Helium compression device. 4. The helium gas compressed by the compressor (11) is cooled through a heat exchanger (12) and then passed through an oil separator (13) for separating gas and oil. ) And sent to the main body (90)
A helium gas outlet (12b) of the heat exchanger (12) and a helium gas inlet of the oil separator (13) in the helium compression device for returning the helium gas discharged from the return path to the suction side of the compressor (11). (13a), the main flow path (23) is cut off and the helium gas outlet (12b) of the heat exchanger (12) and the oil return port (11d) of the compressor (11) are cut off. ), Wherein a three-way valve (37) capable of forming a bypass flow path is interposed therebetween.