JP2000310455A - Helium compression device - Google Patents

Abstract

(57) [Summary] [Problem] To obtain a refrigeration capacity without variation. A high pressure line and a low pressure line are connected by a bypass line. In the bypass line 14,
The capillary tube 15 and the solenoid valve 16 are interposed in series. The differential pressure switch 17 detects a differential pressure between the high voltage line 12 and the low voltage line 13, and outputs a detection signal when the pressure exceeds a predetermined value. When receiving the detection signal, the solenoid valve control unit 18 opens the solenoid valve 16 to allow the high-pressure helium gas in the high-pressure line 12 to escape to the low-pressure line 13. Thus, the capillary tube 1 that operates accurately with little product variation
5. By using the solenoid valve 16 and the differential pressure switch 17 to adjust the differential pressure between the high-pressure line 12 and the low-pressure line 13 at the time of startup, a stable refrigeration capacity without variation is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a helium compression device for supplying high-pressure helium gas to a helium refrigerator.

[0002]

2. Description of the Related Art As a helium compression device for supplying high-pressure helium gas to a helium refrigerator, there is one as shown in FIG. This helium compression device is schematically composed of a compressor 1, a heat exchanger 2, an oil separator 3, and an adsorber 4. The helium gas compressed by the compressor 1 is cooled by a water-cooled heat exchanger 2 while circulating around the compressor 1, lubricating oil is separated by an oil separator 3, and an oil separator is separated by an adsorber 4. The lubricating oil which cannot be completely separated in 3 is adsorbed. Then, the high-pressure helium gas from which the oil has been removed is supplied to a refrigerator (not shown) via the high-pressure line 5.

On the other hand, the low-pressure helium gas from the refrigerator is combined with the lubricating oil separated by the oil separator 3 via the low-pressure line 6 and returned to the compressor 1.

Meanwhile, the helium gas has a large density change depending on the temperature. Therefore, at the time of start-up, the density of the helium gas discharged from the compressor 1 (that is, the helium gas supplied to the refrigerator) is larger than at the time of steady operation. Therefore, the pressure difference between the high-pressure line 5 and the low-pressure line 6 becomes larger than that in the normal operation, and if left as it is, it may cause a failure of the compressor 1.

Therefore, the high-pressure line 5 and the low-pressure line 6
And a bypass pressure control valve 8 is interposed in the bypass line 7. As the differential pressure control valve 8, for example, a spring offset type two-port valve that uses both the high pressure line 5 and the low pressure line 6 as pilot pressure is used. When the pressure difference between the high pressure line 5 and the low pressure line 6 exceeds the spring force of the spring,
By opening the bypass line 7, the high-pressure helium gas on the high-pressure line 5 is allowed to escape to the low-pressure line 6 at a predetermined flow rate.

[0006]

However, the above conventional helium compression apparatus has the following problems. That is, as described above, the high pressure line 5 and the low pressure line 6 are connected to the bypass line 7 in which the differential pressure control valve 8 is provided.
When the pressure difference between the high pressure line 5 and the low pressure line 6 at the time of startup exceeds a predetermined pressure, the operation of the differential pressure control valve 8 causes the high pressure helium gas on the high pressure line 5 side to move to the low pressure line 6 side. I try to escape.

However, in the differential pressure control valve 8 described above,
Since there is a variation in the spring constant of the spring used, there is also variation in the differential pressure control ability between the high-pressure line 5 and the low-pressure line 6 between the helium compression devices. As a result, there is a problem that the refrigerating capacity between the refrigerators varies.

An object of the present invention is to provide a helium compression device capable of obtaining a refrigeration capacity with no variation.

[0009]

According to a first aspect of the present invention, there is provided a helium compression apparatus comprising: a high-pressure line for supplying high-pressure helium gas discharged from a compressor to a refrigerator; A bypass line that communicates with the low-pressure line that returns the discharged low-pressure helium gas to the compressor; a flow control unit and a switching unit that are provided in series with the bypass line; and a differential pressure between the high-pressure line and the low-pressure line. And a control means for opening the opening / closing means when a differential pressure between the high-pressure line and the low-pressure line becomes a predetermined value or more based on a signal from the differential pressure detecting means. Features.

According to the above configuration, at the time of startup, since the density of the helium gas discharged from the compressor is higher than in the normal operation, the differential pressure between the high-pressure line and the low-pressure line is higher than in the normal operation. When the differential pressure becomes equal to or more than a predetermined value, the control means opens the opening / closing means provided on the bypass line connecting the high pressure line and the low pressure line based on a signal from the differential pressure sensing means. .
Thus, the high-pressure helium gas in the high-pressure line is released to the low-pressure line at a predetermined flow rate through the flow rate adjusting means.

The invention according to claim 2 comprises a high-pressure line for supplying high-pressure helium gas discharged from the compressor to the refrigerator and a low-pressure line for returning low-pressure helium gas discharged from the refrigerator to the compressor. , A flow adjusting means and an opening / closing means interposed in series with the bypass line, a first pressure detecting means for detecting the pressure of the high pressure line, and a second pressure detecting means for detecting the pressure of the low pressure line. When the pressure of the high-pressure line becomes equal to or higher than a first predetermined pressure and the pressure of the low-pressure line becomes equal to or lower than a second predetermined pressure based on signals from the pressure detecting means and the first and second pressure detecting means, A control means for opening the opening / closing means is provided.

According to the above configuration, at the time of startup, the density of the helium gas discharged from the compressor is higher than that in the steady operation, so that the differential pressure between the high pressure line and the low pressure line becomes larger than that in the steady operation. When the pressure in the high-pressure line becomes equal to or higher than a first predetermined pressure, and when the pressure in the low-pressure line becomes equal to or lower than a second predetermined pressure, the control unit, based on a signal from the first and second pressure detection units, Opening / closing means interposed in a bypass line communicating the high pressure line and the low pressure line is opened. Thus, the high-pressure helium gas in the high-pressure line is released to the low-pressure line at a predetermined flow rate through the flow rate adjusting means.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. <First Embodiment> FIG. 1 is a partial configuration diagram of a helium compression device of the present embodiment. The helium compressor of the present embodiment also has a compressor, a heat exchanger, and an oil separator, and is compressed by the compressor, as in the case of the conventional compressor helium compressor shown in FIG. Helium gas is cooled by a water-cooled heat exchanger, and lubricating oil is separated by the oil separator. However, in FIG. 1, the compressor, the heat exchanger, and the oil separator are omitted.

The high-pressure helium gas from which the lubricating oil has been separated by the oil separator as described above is supplied to the adsorber 11.
Supplied to Then, after the lubricating oil that cannot be separated by the oil separator is adsorbed by the adsorber 11, the lubricating oil is supplied to a refrigerator (not shown) via the high-pressure line 12. On the other hand, the low pressure helium gas from the compressor is supplied to the low pressure line 1
3 to the compressor.

In the present embodiment, the high pressure line 12 and the low pressure line 13 are connected by a bypass line 14,
In the bypass line 14, a capillary tube 15 as the flow rate adjusting means and the solenoid valve 1 as the opening / closing means are provided.
6 are interposed in series. Note that an orifice may be used as the flow rate adjusting means. Further, a differential pressure switch 17 as the differential pressure detecting means for detecting a differential pressure between the high pressure line 12 and the low pressure line 13, and the opening and closing of the solenoid valve 16 based on a detection signal from the differential pressure switch 17. An electromagnetic valve control unit 18 is provided as control means.

The helium compression device having the above configuration operates as follows. When the compressor is started, the density of the helium gas discharged from the compressor becomes larger than in the normal operation. Therefore, the high pressure line 12 and the low pressure line 13
Is greater than during steady-state operation. Then, the pressure difference is detected by the differential pressure switch 17,
When the detected pressure difference reaches a preset pressure difference, a detection signal is output to the solenoid valve control unit 18. Then, the solenoid valve control unit 18 outputs a control signal to the solenoid valve 16 to open the solenoid valve 16. Then, part of the high-pressure helium gas flowing through the high-pressure line 12 is released to the low-pressure line 13 via the bypass line 14. In this case, the bypass flow rate is adjusted to a predetermined flow rate by the capillary tube 15 as the flow rate adjusting means.

As a result, the pressure in the high pressure line 12 starts to decrease, and the pressure difference between the high pressure line 12 and the low pressure line 13 decreases. Then, when the pressure difference reaches the set differential pressure, the detection signal from the differential pressure switch 17 is stopped. Then, the electromagnetic valve control unit 18 controls the electromagnetic valve 1
6 to output a control signal, and the solenoid valve 16 is closed. Thereafter, the above-described operation is repeated, and the pressure difference between the high-pressure line 12 and the low-pressure line 13 is controlled so as not to exceed the set differential pressure.

Thus, when the operation of the compressor is continued while the pressure difference is controlled not to exceed the set pressure difference, the density of the helium gas discharged from the compressor with the elapse of the operation time is increased. Is getting smaller. Thus, the pressure difference between the high-pressure line 12 and the low-pressure line 13 eventually falls within the pressure difference in the steady operation state within the above-mentioned set differential pressure. Then, thereafter, the differential pressure switch 17
The operation of the solenoid valve control unit 18 is stopped until the next startup.

As described above, in the present embodiment,
A capillary tube 15 and a solenoid valve 16 are connected to a bypass line 14 connecting the high pressure line 12 and the low pressure line 13.
And are interposed in series. Further, a differential pressure switch 17 for detecting a differential pressure between the high pressure line 12 and the low pressure line 13 is provided. When the compressor is started, the differential pressure switch 17 detects that the differential pressure between the high-pressure line 12 and the low-pressure line 13 exceeds a predetermined value, and based on a detection signal from the differential pressure switch 17, the electromagnetic valve 16 To release the high-pressure helium gas from the high-pressure line 12 to the low-pressure line 13.

That is, according to the present embodiment, the capillary tube 1 that operates accurately with little product variation.
5 and the orifice, solenoid valve 16 and differential pressure switch 17, the high pressure line 12 and the low pressure line 1
3 can be adjusted. Therefore, a stable refrigeration capacity without variation can be obtained.

<Second Embodiment> In the first embodiment, the differential pressure between the high voltage line 12 and the low voltage line 13 is detected by the differential pressure switch 17. By the way, the differential pressure switch 17 detects the high pressure side and the low pressure side pressure and detects the differential pressure, so that the structure is complicated and expensive. Therefore, in the present embodiment, the configuration of the differential pressure detecting means is further simplified to reduce the cost.

FIG. 2 is a partial configuration diagram of the helium compression device according to the present embodiment. The helium compression device of the present embodiment also has a compressor, a heat exchanger, an oil separator, and an adsorber 21 as in the case of the conventional compressor helium compression device shown in FIG. The compressed helium gas is cooled by a water-cooled heat exchanger, the lubricating oil is separated by the oil separator, and the adsorber 21 adsorbs residual oil. However, in FIG. 2, the compressor, the heat exchanger, and the oil separator are omitted.

In this embodiment, similarly to the first embodiment, the high pressure line 22 and the low pressure line 23 are connected by a bypass line 24, and a capillary tube 25 and a solenoid valve 26 are connected in series to the bypass line 24. It is interposed in. Further, a high pressure line 22 is used as the differential pressure detecting means.
Pressure switch 27 and low pressure line 2 for detecting the pressure of
And a second pressure switch 28 for detecting the pressure of the third pressure. An electromagnetic valve control unit 2 that controls opening and closing of the electromagnetic valve 26 based on detection signals from the two pressure switches 27 and 28.
9 are provided.

The helium compression device having the above configuration operates as follows. When the compressor is started, the high pressure line 12
The pressure difference between the low pressure line 13 and the low pressure line 13 is larger than that during normal operation. Then, the pressure of the high pressure line 22 detected by the first pressure switch 27 is set to a predetermined first pressure.
When the pressure value is reached, a detection signal is output from the first pressure switch 27 to the solenoid valve controller 29. Further, when the pressure of the low pressure line 23 detected by the second pressure switch 28 reaches a preset second pressure value, a detection signal is output from the second pressure switch 28 to the solenoid valve control unit 29. Then, the solenoid valve control unit 29
, And the solenoid valve 26 is opened. Thus, the pressure difference between the high-pressure line 22 and the low-pressure line 23 is controlled so as not to exceed the pressure difference between the pressures set by the pressure switches 27 and 28.

As described above, in the present embodiment,
A capillary tube 25 and a solenoid valve 26 are connected to a bypass line 24 connecting the high pressure line 22 and the low pressure line 23.
And are interposed in series. Further, a first pressure switch 27 for detecting the pressure of the high-pressure line 22 and a low-pressure line 23
And a second pressure switch 28 for detecting the pressure of the pressure. When the compressor is started, the high-pressure line 22
That the pressure exceeds the first set value, the first pressure switch 2
7, and when the second pressure switch 28 detects that the pressure of the low pressure line 23 has exceeded the second set value, the solenoid valve 26 is opened based on the detection signals from both pressure switches 27 and 28. Thus, the high-pressure helium gas in the high-pressure line 22 is allowed to escape to the low-pressure line 23.

That is, according to the present embodiment, the function of the differential pressure switch 17 in the first embodiment is different from that of the differential pressure switch 17 in that the high pressure first pressure switch 27 and the low pressure Since the two pressure switches 28 are provided, a stable refrigeration capacity without variation can be obtained at lower cost.

[0027]

As is apparent from the above description, the helium compression device according to the first aspect of the present invention has a flow rate adjusting means and an opening / closing means interposed in series with a bypass line which connects a high pressure line and a low pressure line. Based on a signal from the pressure detecting means, the control means opens the opening / closing means when the differential pressure between the high-pressure line and the low-pressure line becomes equal to or greater than a predetermined value. When the differential pressure between the high-pressure line and the low-pressure line is larger than that during the steady operation and the differential pressure is equal to or more than a predetermined value, the opening / closing means is opened, and the high-pressure line High-pressure helium gas can be released to the low-pressure line at a predetermined flow rate through the flow rate adjusting means.

In this case, since the function of detecting the differential pressure is not required for the flow rate adjusting means, a capillary tube or an orifice or the like which has a simple mechanism but does not vary in accuracy can be applied. It enables adjustment without variation in the differential pressure between the high pressure line and the low pressure line. Therefore, according to the present invention, a stable refrigeration capacity without variation can be obtained.

According to a second aspect of the present invention, a flow rate adjusting means and an opening / closing means are provided in series with a bypass line connecting the high pressure line and the low pressure line. Based on the signal, the control means causes the opening / closing means to open when the pressure of the high-pressure line becomes equal to or higher than a first predetermined pressure and the pressure of the low-pressure line becomes equal to or lower than a second predetermined pressure. Since the density of the helium gas discharged from the compressor is higher than that during the steady operation, when the differential pressure between the high pressure line and the low pressure line becomes larger than that during the steady operation, the opening / closing means is opened to open the high pressure line. The high-pressure helium gas can escape to the low-pressure line at a predetermined flow rate through the flow rate adjusting means.

In this case, the first and second pressure detecting means only need to have a function of detecting a certain pressure.
Does not require a function to detect the differential pressure between two pressures,
Simple structure and low cost. Therefore, according to the present invention, a stable refrigeration capacity without variation can be obtained at lower cost than in the case of the invention according to claim 1.

[Brief description of the drawings]

FIG. 1 is a partial configuration diagram of a helium compression device according to the present invention.

FIG. 2 is a partial configuration diagram of a helium compression device different from FIG.

FIG. 3 is a configuration diagram of a conventional helium compression device.

[Explanation of symbols]

11,21 ... Adsorber, 12,22 ... High pressure line,
13, 23: low pressure line, 14, 24: bypass line, 15, 25: capillary tube,
16, 26: solenoid valve, 17: differential pressure switch, 18, 29: solenoid valve control unit, 27: first pressure switch, 28: second pressure switch.

Claims (2)

[Claims] 1. A high-pressure line (12) for supplying high-pressure helium gas discharged from a compressor to a refrigerator and a low-pressure line (13) for returning low-pressure helium gas discharged from the refrigerator to the compressor. A flow control means (15) and an opening / closing means (16) provided in series with the bypass line (14); and a differential pressure between the high pressure line (12) and the low pressure line (13). And a low pressure line (13) based on a signal from the differential pressure detection means (17) when the pressure difference between the high pressure line (12) and the low pressure line (13) is equal to or greater than a predetermined value. Control means for opening the opening / closing means (16)
A helium compression device comprising (18). 2. A high pressure line (22) for supplying high pressure helium gas discharged from a compressor to a refrigerator and a low pressure line (23) for returning low pressure helium gas discharged from the refrigerator to the compressor. A bypass line (24), a flow control means (25) and an opening / closing means (26) provided in series with the bypass line (24), and a first pressure detection for detecting the pressure of the high pressure line (22). Means (27); second pressure detecting means (28) for detecting the pressure of the low pressure line (23); and the high pressure based on signals from the first and second pressure detecting means (27, 28). A control means (29) for opening the opening / closing means (26) when the pressure of the line (22) becomes equal to or higher than the first predetermined pressure and the pressure of the low pressure line (23) becomes equal to or lower than the second predetermined pressure. A helium compression device, characterized in that: