JP2000310453A - Oil cooler for helium compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a heat exchange efficiency of a lubricant while reducing a pulsation of a pressure. SOLUTION: A single route 19 for an oil single phase fluid connected in series with a plurality of path routes, and a plurality of branched routes 18 for two phase flow fluids are provided in a heat exchanger 12. Thus, the route for the oil single phase fluid is formed in a single route to eliminate lowering of a flowing velocity, thereby improving a heat exchange efficiency. A surge volume 21 for alleviating a pressure pulsation is provided at oil pouring piping 20 for pouring an oil content from an oil separator 13 in a compressor 11. Thus, a damper of the pulsation due to a discontinuous flow is provided to absorb a pressure change affecting the piping 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a helium compressor oil cooling device provided in a helium compressor unit for cooling lubricating oil of the helium compressor.

[0002]

2. Description of the Related Art Conventionally, there is an air-cooled helium compressor unit as shown in FIG. In this helium compressor unit, the first discharge port 4
And a second discharge port 5. And the first discharge port 4
A mixed fluid (hereinafter, referred to as a two-phase flow fluid) in which high-pressure helium gas and lubricating oil are supplied to a helium refrigerator unit (not shown) is discharged. On the other hand, a single-phase fluid of the lubricating oil cooled by the heat exchanger 2 (hereinafter, referred to as an oil single-phase fluid) is discharged from the second discharge port 5.
Then, the two-phase flow fluid and the oil single-phase fluid discharged from the compressor 1 are both supplied to the heat exchanger 2 and cooled.

Here, in the case of the two-phase flow fluid, in order to reduce the pressure loss, the fluid path in the heat exchanger 2 needs to have a plurality of branch path structures rather than a single path structure. . Therefore, in the conventional heat exchanger 2, not only the two-phase flow fluid but also the oil single-phase fluid has a plurality of branch paths in order to reduce costs and improve productivity. .

[0004] The two-phase flow fluid discharged from the first discharge port 4 of the compressor 1 is cooled by branching and passing through a plurality of branch paths 6 in the heat exchanger 2. At high pressure to separate into high-pressure helium gas and oil. The high-pressure helium gas is supplied to the helium refrigerator unit, while the oil is injected into the compressor 1 from the oil inlet 9 through the oil injection pipe 8. The oil single-phase fluid discharged from the second discharge port 5 of the compressor 1 is cooled by branching and passing through a plurality of branch paths 7 in the heat exchanger 2, and is joined to the oil injection pipe 8. Oil is injected into the compressor 1 from an oil inlet 9.

[0005]

However, the conventional oil cooling device for a helium compressor has the following problems. That is, the fluid path of the heat exchanger 2 is
In order to reduce costs and improve productivity, not only the two-phase fluid but also the oil single-phase fluid has a branch path structure. Therefore, the flow rate of the oil single-phase fluid is reduced due to the effect of the plurality of branched paths 7, and the heat exchange efficiency is reduced. Therefore, the temperature of the oil returned to the compressor 1 becomes high, that is, the temperature of the entire compressor 1 becomes high, so that there is a problem that reliability is reduced.

Therefore, in order to improve the heat exchange efficiency by eliminating the decrease in the flow velocity of the oil single-phase fluid in the fluid path in the heat exchanger 2, the fluid path of the oil single-phase fluid is changed to a single path. Although the flow velocity increases, the compressor 1
There is a problem that a phenomenon similar to a water hammer occurs in the oil injection pipe 8 that returns oil to the pipe, and the pipe is broken due to pressure pulsation. The water hammer is a compressor 1
Is a phenomenon that the fluid flows intermittently instead of continuously because the oil inlet 9 repeatedly opens and closes in the compression process.

It is an object of the present invention to provide an oil cooling device for a helium compressor which can improve the heat exchange efficiency of lubricating oil while reducing pressure pulsation.

[0008]

In order to achieve the above object, an invention according to claim 1 comprises a compressor for compressing helium gas and a heat exchanger for cooling helium gas and oil discharged from the compressor. In the oil cooling device for a helium compressor having a helium compressor, the heat exchanger is provided with a series path for an oil single-phase fluid formed by connecting a plurality of one-path paths in series, and passes through the series path of the heat exchanger. An oil injection pipe for guiding an oil single-phase fluid to an oil injection port of the compressor, and a surge volume provided in the oil injection pipe are provided.

According to the above construction, the oil single-phase fluid of the lubricating oil discharged from the compressor is cooled by passing through the series path of the heat exchanger, and is injected into the compressor from the oil inlet through the oil injection pipe. Is done. In this case, the oil single-phase fluid does not decrease in flow velocity because it passes through the series path, and is compared to a case where a branch path heat exchanger having the same number of branches as the number of one-path paths connected in series is used. Heat exchange efficiency is improved. Further, since the oil injection pipe is provided with a surge volume, the surge volume plays a role of a damper for pressure pulsation due to a discontinuous flow. Therefore, the stress fluctuation exerted on the oil injection pipe is absorbed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. FIG. 1 is a diagram showing a schematic configuration of an oil cooling device of a helium compressor according to the present embodiment. In FIG. 1, a compressor 11 is provided with a first discharge port 14, a second discharge port 15, an oil injection port 16, and a suction port 17. Then, a two-phase flow fluid in which high-pressure helium gas and lubricating oil supplied to a helium refrigerator unit (not shown) are mixed is discharged from the first discharge port 14. On the other hand, the second
From the discharge port 15, an oil single-phase fluid cooled by the heat exchanger 12 is discharged. The lubricating oil separated by the oil separator 13 is injected from the oil inlet 16. Helium gas decompressed by the helium refrigerator unit is sucked from the suction port 17.

The fluid path of the two-phase flow fluid in the heat exchanger 12 is a multiple branch path 18 having a plurality of branch path structures to reduce pressure loss. On the other hand, the fluid path of the oil single-phase fluid is a single path 19 formed by connecting a plurality of one-pass paths in series in order to reduce a decrease in flow velocity.

The first discharge port 14 of the compressor 11
Is cooled by branching and passing through a plurality of branch paths 18 in the heat exchanger 12, and separated into high-pressure helium gas and oil by the oil separator 13. The high-pressure helium gas is supplied to the helium refrigerator unit, while the oil is injected into the compressor 11 from the oil inlet 16 through the oil injection pipe 20. Also,
The oil single-phase fluid discharged from the second discharge port 15 of the compressor 11 is cooled by passing through the single path 19 in the heat exchanger 12, merges with the oil injection pipe 20, and flows from the oil injection port 16. It is injected into the compressor 11. Here, in the present embodiment, a surge volume 21 is interposed in the oil injection pipe 20.

In this case, the single path 19 through which the oil single-phase fluid passes in the heat exchanger 12 is configured by connecting a plurality of one-path paths in series. Therefore,
If the number of one-path paths connected in series is the same as the number of branches of the plurality of branch paths in the above-described conventional heat exchanger, the heat of the single-phase fluid does not decrease because the flow rate is not reduced because of the single path. The exchange efficiency can be improved as compared with the conventional heat exchanger.

In the present embodiment, a surge volume 21 for reducing pressure pulsation is provided in the oil injection pipe 20. In this way, the oil is temporarily
The surge volume 21 plays a role of a damper for pressure pulsation due to a discontinuous flow by being injected into the compressor 11 after being stored in the compressor. Accordingly, the pressure pulsation of the oil injection pipe 20 accompanying the improvement of the flow rate of the single-phase fluid is absorbed, and the stress fluctuation exerted on the oil injection pipe 20 is reduced. As a result, defects such as breakage of the oil injection pipe 20 are eliminated. The surge volume 21 may be installed anywhere on the oil injection pipe 20.

[0015]

As is apparent from the above description, the oil cooling system for a helium compressor according to the first aspect of the present invention is a series connection for a single-phase oil fluid in which a plurality of one-pass paths are connected in series to a heat exchanger. A surge volume is provided in the oil injection pipe that guides the oil single-phase fluid that has passed through the serial path to the oil inlet of the compressor, so that a decrease in the flow velocity of the oil single-phase fluid that passes through the serial path can be reduced. . Therefore, if the number of one-pass paths constituting the series path is equal to the number of branches of the branch path in the conventional heat exchanger, the heat exchange efficiency of the oil single-phase fluid is improved as compared with the conventional heat exchanger. it can.

Further, since the cooled oil single-phase fluid is injected into the compressor through the surge volume provided in the oil injection pipe, the surge volume can function as a damper for pressure pulsation due to a discontinuous flow. it can. Therefore, according to the present invention, the pressure pulsation of the oil injection pipe due to the improvement of the flow velocity of the single-phase fluid can be absorbed by the surge volume, and the fluctuation of the stress applied to the oil injection pipe can be reduced to eliminate a problem such as breakage. It is.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an oil cooling device for a helium compressor according to the present invention.

FIG. 2 is a diagram showing a schematic configuration of a conventional oil cooling device of a helium compressor.

[Explanation of symbols]

11: compressor, 12: heat exchanger, 13: oil separator,
14: first discharge port, 15: second discharge port, 16: oil injection port, 17: suction port, 18: multiple branch path, 19
... single path, 20 ... oil injection pipe,
21 ... Surge volume.

Claims (1)

[Claims] A compressor for compressing a helium gas.
And a helium compressor oil cooling device having a heat exchanger (12) for cooling helium gas and oil discharged from the compressor (11), wherein the heat exchanger (12) includes a plurality of one-pass paths. Are connected in series, and a serial path (19) for an oil single-phase fluid is provided. The oil single-phase fluid that has passed through the serial path (19) of the heat exchanger (12) is supplied to the oil injection of the compressor (11). An oil injection pipe (20) leading to the inlet (16); and a surge volume (2) provided in the oil injection pipe (20).
An oil cooling device for a helium compressor, comprising: