JP2002039638A - Cryogenic freezer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cryogenic freezer which can be installed easily. SOLUTION: In the main line 33 for connecting an outdoor compressor unit 1 which has a compressor 11 and a heat exchanger 12 with a cryogenic expander 5, the supply pope 31 and the return pipe 32 of the main line 33 are connected with each other by connection pipe 42 wherein an electrically operated valve 41 is interposed. A controller 46 controls the electrically operated valve 41 so that helium may flow at a specified flow rate to the cryogenic expander 5, based on the length and shape of the main line 33 and the helium gas pressure on the suction side of the compressor 11. By doing it so, there is no necessity to compute the charge pressure corresponding to the length and shape of the main line 33 and charge a freezer with helium gas so that it may come to the charge pressure when the user installs the cryogenic freezer, so the installation work of the cryogenic freezer can be facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cryogenic refrigeration system using a refrigerant gas such as helium.

[0002]

2. Description of the Related Art Conventionally, there is a cryogenic refrigeration system of this type as shown in FIG. This cryogenic refrigeration apparatus includes an outdoor compressor unit 1 arranged outdoors and a cryogenic expander 5 arranged indoors.

The outdoor compressor unit 1 includes a helium gas compressor 11, a heat exchanger 12 interposed in a discharge pipe 21 of the compressor 11, and a discharge side at an outlet side of the heat exchanger 12. The oil separator 13 is provided on the pipe 21. A gas supply pipe 31 is connected to a distal end of the discharge-side pipe 21 connected to a discharge side of the compressor 11, and a suction-side pipe 2 connected to a suction side of the compressor 11.
A gas return pipe 32 is connected to the tip of the second. The gas supply pipe 31 is connected to a high-pressure side communication pipe 51 that communicates with the cryogenic expander 5, and the gas return pipe 32 is connected to a low-pressure side communication pipe 52 that communicates with the cryogenic expander 5. . A main line 33 is formed by the gas supply pipe 31 and the gas return pipe 32, and the main line 33 is arranged behind the ceiling of a building or the like. Cryogenic expander 5 to be connected.

In the cryogenic refrigeration system having the above-described structure, the high-temperature and high-pressure helium gas compressed by the compressor 11 of the outdoor compressor unit 1 is cooled by exchanging heat with outdoor air in the heat exchanger 12. After the oil is removed by the oil separator 13, the oil is guided to the cryogenic expander 5 through the discharge-side pipe 21, the gas supply pipe 31, and the high-pressure-side communication pipe 51. Then, the high-pressure helium gas cooled by the cold storage material (not shown) in the cryogenic expander 5 is connected to a low-pressure chamber (not shown) and expands at a stretch to lower the gas temperature. The helium gas expanded in the cryogenic expander 5 is supplied to the low-pressure side communication pipe 52.
Through the cryogenic expander 5 through the gas return pipe 3
2. Return to the suction side of the compressor 11 via the suction side pipe 22. Helium gas circulates through such a refrigeration path, and cool heat is accumulated in a cold storage material (not shown) provided in the cryogenic expander 5, and a cryogenic temperature is obtained in the cryogenic refrigeration apparatus 5.

When the cryogenic refrigeration system is installed, helium gas is filled into the outdoor compressor unit 1, the cryogenic expander 5, and the main line 33 which form the refrigeration path. At this time, in order to make the helium gas flow rate in the cryogenic expander 5 during the operation of the cryogenic refrigeration apparatus a predetermined flow rate, the filling pressure of the helium gas must be adjusted according to the length and shape of the main line 33. Must.
Because if the length of the main line 33 changes,
This is because the volume of helium gas charged in the refrigeration path changes. Further, if the length, the bending angle, and the number of bending of the main line 33 change, the pressure loss of helium gas during the operation of the cryogenic refrigeration apparatus changes. That is, every time the cryogenic refrigeration apparatus is installed, the helium gas filling pressure corresponding to the pressure loss due to the length, the bending angle, and the number of bends of the main line 33 is calculated, and the cryogenic refrigeration is adjusted to the filling pressure. The inside of the device is filled with helium gas.

[0006]

However, in the conventional cryogenic refrigerator described above, every time the cryogenic refrigerator is installed, the filling pressure is calculated based on the length, the bending angle and the number of bending of the main line 33. However, there is a problem that it takes a lot of trouble to fill the helium gas to the filling pressure.

Accordingly, an object of the present invention is to provide a cryogenic refrigeration apparatus which can be easily installed without having to set the filling pressure of helium gas according to the length and shape of the main line when installing the cryogenic refrigeration apparatus. To provide.

[0008]

According to a first aspect of the present invention, there is provided a cryogenic refrigeration apparatus comprising: an outdoor compressor unit having a compressor and a heat exchanger; and a cryogenic expander. In a cryogenic refrigeration system connected by a main line consisting of a pipe and a return pipe, a connection pipe that connects between a supply pipe and a return pipe of the main line, and a motor-operated valve is interposed, and the outdoor compressor An opening of the motor-operated valve based on a pressure sensor for detecting a pressure of the refrigerant gas sucked by the compressor of the unit, at least one of a length and a shape of the main line, and a pressure detected by the pressure sensor; And control means for adjusting the

According to the cryogenic refrigeration system of the first aspect, the control means determines the cryogenic temperature based on at least one of the length and shape of the main line and the refrigerant gas pressure on the suction side of the compressor. Calculate the flow rate of the refrigerant gas to flow through the connection pipe in order to make the flow rate of the refrigerant gas in the expander a predetermined flow rate. Then, the opening degree of the motor-operated valve of the connection pipe is adjusted so that the refrigerant gas having this flow rate flows into the connection pipe. Then, the flow rate in the cryogenic expander becomes a predetermined flow rate. That is, even if the cryogenic refrigeration apparatus is charged with the refrigerant gas at a constant filling pressure without corresponding to the length and shape of the main line when the cryogenic refrigeration apparatus is installed, the cryogenic expander is controlled by the control means. An appropriate flow rate of the refrigerant gas flows. Therefore, when installing the cryogenic refrigeration system, it is not necessary to calculate the filling pressure of the refrigerant gas corresponding to the length and shape of the main line and to fill the refrigerant gas to reach the filling pressure. Installation work of the low-temperature refrigeration equipment becomes easy.

According to a second aspect of the present invention, there is provided the cryogenic refrigeration apparatus according to the first aspect, wherein a fan for cooling a heat exchanger of the outdoor compressor unit and an outdoor in which the outdoor compressor unit is disposed. A temperature sensor for detecting the air temperature of at least one of the length and the shape of the main line.
And control means for adjusting the opening of the electric valve and the number of revolutions of the fan based on the pressure detected by the pressure sensor and the temperature detected by the temperature sensor. I have.

According to the cryogenic refrigeration system of the second aspect, the control means controls the outdoor air temperature in addition to one of the length and shape of the main line and the refrigerant gas pressure on the suction side of the compressor. Based on the above, the flow rate of the refrigerant gas to be flown through the connection pipe in order to flow the predetermined flow rate of the refrigerant gas through the cryogenic expander is calculated. Then, the opening degree of the motor-operated valve of the connection pipe is adjusted and the rotation speed of the fan for cooling the heat exchanger of the outdoor compressor unit is adjusted so that the refrigerant gas having this flow rate flows into the connection pipe. Then, the flow rate in the cryogenic expander becomes a predetermined flow rate according to the outdoor temperature in addition to the length and shape of the main line. That is,
This cryogenic refrigeration system ensures that an appropriate flow rate flows through the cryogenic expander at any mainline length, shape and outdoor temperature. Therefore, when installing the cryogenic refrigeration system, it is not necessary to calculate the filling pressure of the refrigerant gas corresponding to the length and shape of the main line and to fill the refrigerant gas to reach the filling pressure. Installation work of the low-temperature refrigeration equipment becomes easy.

[0012]

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 refrigerant circuit diagram of the cryogenic refrigeration apparatus according to the first embodiment. The cryogenic refrigeration system includes a connection pipe 42 provided with an electric valve 41 and a pressure sensor 44.
The configuration is the same as that of the cryogenic refrigeration apparatus shown in FIG. 3 except that the cryogenic refrigeration apparatus shown in FIG. 3 is provided, and the same parts as those in FIG.

The cryogenic refrigeration system includes a main line 33
A connection pipe 42 for connecting between the gas supply pipe 31 and the gas return pipe 42 is provided, and an electric valve 41 is interposed in the connection pipe 42. In the outdoor compressor unit 1, a compressor 11 is connected to a suction pipe 22 connected to a suction side of the compressor 11.
A pressure sensor 44 for detecting the pressure of the helium gas sucked into the helium gas. Further, the cryogenic refrigeration apparatus includes a control device 46 including a CPU (Central Processing Unit) as control means. The control device 46 is connected to the pressure sensor 44 and the motor-operated valve 41. The control device 46 is configured to input the length L (m) of the main line 33 and the number of bent portions as the shape of the main line 33 from the input section. The number of the bent portions is
"No bend" and "One to three bends"
And three choices of "four or more bends". Further, the control device 46 stores a table indicating the opening degree of the electric valve 41 corresponding to the length of the main line 33, the number of bent portions, and the helium gas pressure. This table is determined in advance by experiments.

At the time of installing the cryogenic refrigeration system having the above-described configuration, the outdoor compressor unit 1, the cryogenic expander 5, and the main line 33 forming the refrigeration path are filled with helium gas. The filling pressure of the helium gas is a predetermined filling pressure regardless of the length of the main line 33. After that, the above-mentioned control device 6 is input to the above-mentioned
The length L (m) of the main line 33 and the number of bent portions of the main line are input. After the installation of the cryogenic refrigerator is completed, the cryogenic refrigerator is operated. That is, the compressor 11 of the outdoor compressor unit 1 is started, and circulation of helium gas inside the outdoor compressor unit 1, the main line 33, and the inside of the cryogenic expander 5 is started. Then, the controller 46 determines the table L based on the input length L (m) of the main line 33, the number of bent portions of the main line, and the pressure of the helium gas detected by the pressure sensor 44. , The opening of the electric valve 41 is obtained. Then, the control device 46 controls the electric valve 41 so that the opening degree is obtained from the table. Then, an appropriate amount of helium gas flows through the connection pipe 42 and a predetermined helium gas flow flows through the cryogenic expander 5, so that the cryogenic expander 5 appropriately performs a refrigeration operation.

The above cryogenic refrigeration system can be used even if helium gas is filled at a constant filling pressure without considering the length of the main line 33 and the number of bent portions when installing the cryogenic refrigeration system. An appropriate flow rate of helium gas flows through the cryogenic expander 5 by the controller 46.
Therefore, this cryogenic refrigeration apparatus calculates the filling pressure of helium gas in accordance with the length of the main line 33 and the number of bends when installing the cryogenic refrigeration apparatus as in the related art, and calculates the filling pressure. It is not necessary to fill helium gas so that Therefore, the cryogenic refrigerator can be easily installed.

FIG. 2 is a refrigerant circuit diagram of the cryogenic refrigeration apparatus according to the second embodiment. The cryogenic refrigeration system includes a connection pipe 42 provided with an electric valve 41 and a pressure sensor 44.
3 has the same configuration as that of the cryogenic refrigeration apparatus shown in FIG. 3 except that it has a temperature sensor 48, a fan 49, and a control device 51, and the same parts as those in FIG. And a detailed description is omitted.

This cryogenic refrigeration system is the first type shown in FIG.
In addition to the cryogenic refrigeration system of the embodiment, the outdoor compressor unit 1 is provided with a temperature sensor 48 for detecting an outdoor temperature and a fan 49 for cooling the heat exchanger 12. The control device 51 receives a signal from the temperature sensor 48 in addition to a signal from the pressure sensor 44. Then, based on these signals and the length of the main line 33 and the number of bent portions input from an input unit (not shown), the opening degree of the electric valve 41 of the connection pipe 42 and the rotation speed of the fan 49 are controlled. It is supposed to. That is, the control device 46 receives the input of the length and the number of bent portions of the main line 33, the helium gas pressure on the suction side of the compressor 11, and the outdoor temperature, and controls the electric valve 41 corresponding to this input. Referring to a table that outputs the opening degree and the rotation speed of the fan 49, the opening degree of the motor-operated valve 41 and the fan 49
Find the number of rotations. Then, the electric valve 41 is controlled so as to have the determined opening degree, and the fan 49 is controlled so as to have the determined rotation speed.

The cryogenic refrigeration system having the above-described structure refers to the outside air temperature in addition to the length of the main line 33 and the helium gas pressure on the suction side of the compressor 11 and the electric valve 41 of the connection pipe 42. The fan 44 is controlled. Then, the flow rate of the helium gas flowing through the connection pipe 42 becomes appropriate, and the heat exchanger 12 of the outdoor compressor unit 1 is appropriately cooled. As a result, the helium gas flow rate of the cryogenic expander 5 can be properly adjusted in accordance with the outdoor temperature in addition to the length and the amount of bending of the main line 33. Therefore, when installing the cryogenic refrigeration apparatus, it is not necessary to calculate the filling pressure of helium gas according to the length of the main line 33 and fill the helium gas to reach the filling pressure as in the related art. Therefore, the work of installing the cryogenic refrigeration apparatus can be facilitated.

In the above embodiment, the pressure sensor 44 is arranged on the suction side of the compressor 11, but may be arranged on the discharge side of the compressor 11.

In the above embodiment, the control devices 46 and 5
Although the length of the main line 33 and the number of bent portions are input to 1, the values input to the control devices 46 and 51 may be any one of the length, the bending angle, and the number of bends of the main line 33. Further, although the number of bent portions is input as the shape of the main line 33, the input shape of the main line 33 may be another shape such as the bending angle or the number of bendings of the main line 33. Alternatively, the amount of helium gas pressure loss due to the length and shape of the main line 33 may be input.

Further, the control devices 46 and 51 refer to predetermined tables based on the length of the main line 33 and the number of bent portions and signals from the pressure sensor 44 and the temperature sensor 48, and The opening of the valve 41 and the number of revolutions of the fan 44 were obtained, but without using a table,
The opening degree of the electric valve 41 and the rotation speed of the fan 44 may be obtained by substituting the length of the main line 33 into a function.

[0023]

As is clear from the above, according to the cryogenic refrigeration system of the first aspect of the present invention, the cryogenic refrigeration system is based on at least one of the length and shape of the main line and the refrigerant gas pressure on the suction side of the compressor. Therefore, since it has control means for controlling an electric valve interposed in a connection pipe connecting the supply pipe and the return pipe of the main line, the length and shape of the main line and the refrigerant gas pressure correspond to A predetermined flow rate of the refrigerant gas can flow through the cryogenic expander. Therefore, when installing the cryogenic refrigeration apparatus, it is not necessary to fill the refrigerant gas with a filling pressure based on the length and shape of the main line, and the installation operation of the cryogenic refrigeration apparatus can be facilitated.

According to the cryogenic refrigeration apparatus of the second aspect of the present invention, the main line is conditioned based on at least one of the length and shape of the main line, the refrigerant gas pressure on the suction side of the compressor, and the outdoor temperature. Since it has control means for controlling a motor-operated valve provided in a connection pipe connecting the supply pipe and the return pipe, and a fan for cooling the heat exchanger, the length and shape of the main line, the refrigerant gas pressure and In response to outdoor temperature,
A predetermined flow rate of the refrigerant gas can be reliably passed through the cryogenic expander. Therefore, when installing the cryogenic refrigeration apparatus, it is not necessary to fill the refrigerant gas with a filling pressure based on the length and shape of the main line, and the installation operation of the cryogenic refrigeration apparatus can be facilitated.

[Brief description of the drawings]

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

FIG. 2 is a refrigerant circuit diagram of a cryogenic refrigeration apparatus according to a second embodiment of the present invention.

FIG. 3 is a refrigerant circuit diagram of a conventional cryogenic refrigerator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outdoor compressor unit 5 Cryogenic expander 11 Compressor 12 Heat exchanger 13 Oil separator 21 Discharge side pipe 22 Suction side pipe 31 Gas supply pipe 32 Gas return pipe 33 Main line 41 Motorized valve 42 Connection pipe 44 Pressure sensor 46 Control device

Claims (2)

[Claims] An outdoor compressor unit (1) having a compressor (11) and a heat exchanger (12) and a cryogenic expander (5) are provided with a supply pipe (31) and a return pipe (32). A cryogenic refrigeration system connected by a main line (33) consisting of: a connection between a supply pipe (31) and a return pipe (32) of the main line (33), and an electric valve (41) interposed. Connection pipe (42), a pressure sensor (44) for detecting the pressure of the refrigerant gas sucked by the compressor (11) of the outdoor compressor unit (1), the length of the main line (33) and Cryogenic temperature control means for controlling the opening of the electric valve (41) based on at least one of the shapes and the pressure detected by the pressure sensor (44). Refrigeration equipment. 2. The cryogenic refrigeration apparatus according to claim 1, wherein a fan (49) for cooling a heat exchanger (12) of the outdoor compressor unit (1) and the outdoor compressor unit (1) are arranged. A temperature sensor (48) for detecting an outside air temperature, at least one of a length and a shape of the main line (33), a pressure detected by the pressure sensor (44), and a temperature sensor (48). A cryogenic refrigeration system comprising: control means (51) for adjusting the opening of the electric valve (41) and the number of revolutions of the fan (49) based on the detected temperature.