JPS60264A - Low-temperature refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a low temperature refrigeration system for obtaining a low temperature of, for example, around -90°C, and in particular to one that reduces the power required at startup and makes its characteristics variable. .

As such refrigeration devices, those with a multi-component refrigeration cycle, those using special refrigerants, etc. are well known. However, in such a low-temperature refrigeration system, each part is at room temperature when it is started, so due to the nature of the refrigerant, the pressure of the refrigerant increases significantly when compressed by a compressor.
Conventionally, there has been a drawback that the load on the compressor increases abnormally. In addition, in the conventional system, the rate of temperature drop over time after startup has remained unreliable, and no consideration has been given to making this variable.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a refrigeration system that solves the above-mentioned problems by providing a refrigerant reservoir in the compressor outlet piping of the conventional refrigeration system via an on-off valve.

An embodiment of this invention will be described in detail below with reference to the drawings.

1 is a refrigerant compressor, 2 is a condenser, 3 is a pressure reducer (capillary tube in this embodiment), and 4 is a cooler, and the discharge side of the compressor 1 - condenser 2 - pressure reducer 3 - cooler 4 - Compressor 1
A refrigeration system R is constructed by connecting these in an annular manner to the suction side of the refrigeration system R. This refrigeration device R uses R503 or R as its refrigerant.
1B was used, and the temperature in the cooler 4 was set to about -90°C.

A refrigerant reservoir 5 is connected to a pipe P between the discharge side of the compressor 1 and the condenser 2 via an electromagnetic on-off valve 6.

Reference numeral 7 denotes an electromagnetically operated on-off valve interposed between the refrigerant reservoir 5 and a pipe P2 between the suction side of the compressor 1 and the outlet of the cooler 4.

Reference numeral 8 denotes a known pressure gauge intended to measure the pressure in the pipe P1.

9 is a motor as a power source for the compressor 1.

Reference numeral 10 denotes a control device that controls starting and stopping of the valves 6 and 7 and the motor 9 by known means. The control device 10 also inputs the output information of the pressure gauge 8.

The operation of the above embodiment will be described below.

It is assumed that this refrigeration apparatus R has been inactive for a long time and the entirety is at room temperature.

The operator operates a start switch (not shown) provided on the control unit 10. The side hearing device 10 starts the motor 9. At the same time, the control device 10 opens the valve 6. Further, the control device 10 detects that the output information from the pressure gauge 8 has reached the maximum and closes the valve 6. Therefore, when the refrigerant is at room temperature (when valve 6 is closed), compressor 1
Since the density of the room-temperature refrigerant flowing through the compressor 1 is small, the shaft power required to rotate the compressor 1 becomes excessive, and the motor 9 should be overloaded, but the valve 6 is opened until the discharge pressure reaches its maximum as described above. By doing so, some of the refrigerant is transferred to the refrigerant reservoir 5.
As the density of the refrigerant decreases, the load of the motor 9 becomes smaller.

According to an example, the refrigerant is R503 and the refrigerant reservoir 5 is 90
When it was set to 0cc, the maximum load at startup of the motor 9 was approximately 2/3.

Thereafter, the refrigeration system will operate in a normal and well-known manner, and if the valve 7 is opened by the operator's manual operation on the control device 10 or by the automatic operation of the control device 10 during this operation, the contents of the reservoir 5 will be reduced. Refrigerant is pipe P2
Due to the low pressure, most of the water returns to the pipe P2 and circulates through the refrigeration system R.

It is also possible to change the rate of temperature drop in the refrigeration system R by adjusting the amount of refrigerant returned.

In the above-mentioned embodiment, the timing for closing the valve 6 was set at the peak of the output of the pressure gauge 8, but the valve 6 may be closed at a predetermined time after activation using this timer or a timer. Alternatively, the valve 6 may be kept open. The shunted refrigerant may be returned to the refrigeration system R by opening the valve 6 instead of opening the valve 7. Other replacements of each component with equivalents within the scope of the technical idea of this invention are also included within the technical scope of this invention.

As described above, this invention connects a refrigerant reservoir to the piping between the compressor discharge side and the condenser inlet via an on-off valve, so that by operating this on-off valve, a refrigerant filled with low-temperature refrigerant can be used. Not only can the load at startup be reduced, but the temperature drop characteristics of the refrigeration system can also be changed by adjusting the amount of working refrigerant.
It can produce unique and remarkable effects.

[Brief explanation of drawings]

The drawing is a block diagram of one embodiment of this invention. 1 compressor, 2 condenser, 3 pressure reducer, 4 cooler,
5... Refrigerant reservoir, 6... Solenoid operated on-off valve, Pl... Piping. Applicant ShinMaywa Industries Co., Ltd.

Claims (2)

[Claims] (1) In a low-temperature refrigeration system in which a compressor, a condenser, a pressure reducer, and a cooler are connected in a ring, a refrigerant reservoir is connected to the piping between the compressor discharge side and the condenser inlet via an on-off valve. The refrigeration device is characterized by: (2) The refrigeration system according to claim 1, wherein the on-off valve is an electromagnetically operated on-off valve.