JP2001336844A - Cryogenic refrigerating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cryogenic refrigerating device that is capable of preventing the occurrence of troubles without enlarging an air-cooled heat exchanger and has a compressor unit installed outdoors. SOLUTION: In a cryogenic refrigerating device having a compressor unit 1 installed outdoors with a compressor 3 compressing helium gas, an air-cooled heat exchanger 5 and a supply fan 7 of this heat exchanger built in, there are provided a discharge temperature sensor 41 detecting the temperature of discharge gas of the compressor 3 and a controlling means 43 controlling the number of revolutions of the supply fan 7 on the basis of the detected temperature of this discharge temperature sensor 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cryogenic refrigerator including a compressor unit and a cryopump, a 4K refrigerator or a pulse tube refrigerator connected thereto.

[0002]

2. Description of the Related Art Generally, a compressor for compressing helium gas, an air-cooled heat exchanger, a compressor unit installed outdoors having a built-in fan for the heat exchanger, and a refrigerator installed indoors are provided. Cryogenic refrigeration systems are known.

In this type, when the compressor unit is installed outdoors, the air-cooled heat exchanger is directly affected by the outside air temperature.

[0004]

In the above configuration, when the outside air temperature is high, the capacity of the heat exchanger must be increased so that the operation can be performed without any trouble even at about 50 ° C., for example. On the other hand, when the outside air temperature is low, if a large-capacity heat exchanger is installed, the helium gas is excessively cooled by this heat exchanger, and helium gas at a minus temperature is supplied to the indoor refrigerator, Condensation occurs in the indoor equipment including pipes, and the oil becomes too cool and becomes too viscous, the fluidity decreases extremely, the compressor is not cooled, and as a result, the discharge gas temperature rises and the operation stops. And other problems occur.

Accordingly, an object of the present invention is to provide a cryogenic refrigeration apparatus having a compressor unit installed outdoors, which can prevent the above-mentioned trouble from occurring without increasing the size of an air-cooled heat exchanger. To provide.

[0006]

According to the first aspect of the present invention,
In a cryogenic refrigeration apparatus having a compressor for compressing helium gas, an air-cooled heat exchanger, and an outdoor compressor unit having a built-in fan for the heat exchanger, the discharge gas temperature of the compressor is detected. A discharge temperature sensor; and control means for controlling a rotation speed of the blower fan based on a temperature detected by the discharge temperature sensor.

According to a second aspect of the present invention, in the first aspect, an outlet temperature sensor for detecting a gas temperature at an outlet of the compressor unit and a gas pipe at an outlet of the compressor unit are provided. An electric heater which is turned on based on the temperature detected by the outlet temperature sensor and heats the helium gas.

According to a third aspect of the present invention, there is provided a cryogenic refrigeration apparatus having a compressor for compressing a helium gas, an air-cooled heat exchanger, and an outdoor compressor unit having a built-in fan for the heat exchanger. An outlet temperature sensor for detecting a gas temperature at an outlet of the compressor unit, and a power supply which is installed in a gas pipe at an outlet of the compressor unit and is turned on based on a temperature detected by the outlet temperature sensor to heat helium gas. And an electric heater.

In these inventions, since the compressor unit is installed outdoors, the indoor space can be effectively used, and the indoor heat load can be reduced. Further, even if the compressor unit is installed outdoors, it is possible to sufficiently cope with fluctuations in the outside air temperature without increasing the capacity of the air-cooled heat exchanger.

[0010]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a compressor unit installed outdoors. The compressor unit 1 includes a compressor 3 for compressing helium gas in its housing, an air-cooled heat exchanger 5, and a blower fan 7 for blowing the heat exchanger 5,
An oil separator 9 and an adsorber 11 are provided. The blower fan 7 has a fan motor 13 driven by an inverter.

A compressor such as a cryopump, a 4K refrigerator, or a pulse tube refrigerator, not shown, is connected to the compressor unit 1. This refrigerator expands helium gas to generate cold. .

The helium gas worked by the refrigerator is returned to the return port 1A of the compressor unit 1 and reaches the compressor 3 via the pipe 21 and the accumulator 22, as shown by the solid arrow. And it is compressed by the compressor 3 and the pipe 2
3, flows into the heat exchanger 5, and further flows through the pipe 24 into the oil separator 9.

In the oil separator 9, helium gas and oil are separated, and the helium gas reaches the adsorber 11 through the pipe 25 as shown by the solid line arrow, and from there, passes through the outlet 1B of the compressor unit 1 to the indoor. It is supplied to a refrigerator whose installation is not shown. A part of the helium gas that has passed through the oil separator 9 passes through a pipe 26, a differential pressure valve 27, a pipe 28, and an accumulator 22, and
Is returned to. Further, helium gas flows through a pipe 29 connected between the compressor 3 and the heat exchanger 5, and the helium gas is cooled.

The oil separated by the oil separator 9 is returned to the compressor 3 via a pipe 31, a capillary tube 32, and a pipe 33, as indicated by dotted arrows. The oil flows from the compressor 3 to the heat exchanger 5 via a pipe 34, and the oil is returned to the compressor 3 via a pipe 35, a capillary tube 36, and a pipe 37. During this time, the oil is cooled.

Since the compressor unit 1 is installed outdoors, the indoor space is effectively used, and the heat load in the room is reduced. However, on the other hand, the air-cooled heat exchanger 5 is directly affected by the outside air temperature.

Generally, when the outside air temperature is high, for example, 50
The capacity of the heat exchanger 5 is designed to be large so that the operation can be performed without any trouble even at about ° C. However, when the heat exchanger 5 is designed to be large, when the outside air temperature is low, the helium gas is excessively cooled by the heat exchanger 5, and helium gas having a minus temperature is supplied to a refrigerator (not shown) installed indoors. Supplied, dew condensation occurs in indoor equipment including pipes, and oil is excessively cooled to increase the viscosity, the fluidity thereof is extremely reduced, the compressor 3 is not cooled, and as a result, the discharge gas temperature increases. , The operation may be stopped.

In this embodiment, the outside air temperature is, for example, -30.
Even if the temperature fluctuates in the range of ° C to + 50 ° C, the above trouble can be prevented beforehand.

That is, an inverter-driven motor operable at, for example, 120 Hz or 80 Hz is used as the fan motor 13. And the discharge pipe 3A of the compressor 3
Is provided with a discharge temperature sensor 41 for detecting the temperature of the discharged helium gas, and control means 43 for controlling the number of revolutions of the fan motor 13 based on the temperature detected by the discharge temperature sensor 41.

For example, when the compressor 3 has a discharge temperature of 130 ° C.
Up to 125 ° C
The control unit 43 controls the rotation speed of the fan motor 13 so that Further, when the fan motor 13 is driven at, for example, 180 Hz, the heat transfer area of the heat exchanger 5 is designed so that the discharge temperature of the helium gas becomes 125 ° C.

According to this, the commercial frequency is 50 Hz or 60 Hz.
The size of the heat exchanger 5 can be reduced as compared with the case where the fan motor 13 is driven at Hz.

Since the size of the heat exchanger 5 can be reduced,
Even when the outside air temperature decreases, the helium gas is cooled too much compared with the case of using a large-capacity heat exchanger, and helium gas of minus temperature is supplied to a refrigerator (not shown) installed indoors, and Condensation may occur on indoor equipment including
The oil is cooled too much and the viscosity increases, the fluidity of the oil is extremely reduced, and the compressor 3 is not cooled. As a result, troubles such as an increase in the discharge gas temperature and a stoppage of the operation are eliminated. You.

Next, in the present embodiment, an outlet temperature sensor 45 for detecting the gas temperature at the outlet 1B of the compressor unit 1.
And an electric heater 47 installed in the gas pipe 46 at the outlet 1B of the compressor unit 1 and powered on based on the temperature detected by the outlet temperature sensor 45 to heat the helium gas.
And these controllers 48 are provided.

According to this, the outlet 1 of the compressor unit 1
The controller 48 controls the power supply to the electric heater 47 so that the helium gas temperature of B does not become a minus temperature, so that the temperature of the gas flowing downstream of the electric heater 47 is increased, and the temperature of the gas is reduced to the indoor equipment including the piping. Dew condensation can be prevented.

Although the present invention has been described based on one embodiment, it is apparent that the present invention is not limited to this.

For example, the control means 43 and the electric heater 4
7 can be combined. According to this,
The capacity of the electric heater 47 can be reduced as compared with the case where only the electric heater 47 is attached.

[0027]

According to the present invention, since the compressor unit is installed outdoors, the indoor space can be effectively used, and the heat load in the room can be reduced. Further, even if the compressor unit is installed outdoors, it is possible to sufficiently cope with fluctuations in the outside air temperature without increasing the capacity of the air-cooled heat exchanger.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of a cryogenic refrigeration apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor unit 1B outlet 3 Compressor 5 Heat exchanger 7 Blower fan 9 Oil separator 11 Adsorber 13 Fan motor 41 Discharge temperature sensor 43 Control means 45 Exit temperature sensor 47 Electric heater

Claims (3)

[Claims] 1. A cryogenic refrigeration system having a compressor for compressing helium gas, an air-cooled heat exchanger, and an outdoor compressor unit having a built-in fan for the heat exchanger. A cryogenic refrigeration apparatus comprising: a discharge temperature sensor for detecting a gas temperature; and control means for controlling a rotation speed of the blower fan based on a temperature detected by the discharge temperature sensor. 2. An outlet temperature sensor for detecting a gas temperature at an outlet of the compressor unit, and a helium switch installed at a gas pipe at an outlet of the compressor unit, which is turned on based on a temperature detected by the outlet temperature sensor and is turned on. 2. The cryogenic refrigeration system according to claim 1, further comprising an electric heater for heating the gas. 3. A cryogenic refrigeration system having a compressor for compressing helium gas, an air-cooled heat exchanger, and a compressor unit installed outdoors having a built-in blower fan of the heat exchanger. An outlet temperature sensor for detecting a gas temperature at an outlet; and an electric heater installed in a gas pipe at an outlet of the compressor unit and turned on based on a temperature detected by the outlet temperature sensor to heat helium gas. A cryogenic refrigeration apparatus characterized by the above-mentioned.