JPS5840102B2 - Refrigeration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cryogenic refrigeration system using, for example, helium gas as a refrigerant.In particular, this invention aims to downsize a gas holder that stores refrigerant gas required at the time of starting a compressor. The aim is to provide a refrigeration system with

Figure 1 is a piping diagram showing a conventional cryogenic refrigeration system of this type.
Reference numeral 1 denotes a refrigerator that has a built-in compressor 2 that pressurizes an inhaled low-temperature, low-pressure gas refrigerant to a high-temperature, high-pressure refrigerant gas of about 15 atmospheres, a filter 3, a condenser, an evaporator, etc. (none of which are shown). A refrigeration cycle consisting of a main body 4, a pressure regulating valve 5, etc., and 6 a variable internal volume gas holder (gas tank) that replenishes refrigerant gas such as helium to the refrigeration cycle 1 when the compressor 2 is started, etc. When the refrigerant gas capacity stored at atmospheric pressure falls below a predetermined value, this gas holder 6 detects this, sends a signal to the control device 7, and opens the gas supply solenoid valve 8. A gas capacity detector 11 is provided for supplying refrigerant gas from a gas cylinder 10 to the gas holder 6 via a pressure regulating valve 9.

Since the conventional cryogenic refrigeration system is configured as described above, the discharge pressure of the refrigerant gas at the time of starting the compressor 2 is:
As shown in Figure 2, approximately 1
Since the pressure rises linearly to 5 atm (point a), it is necessary to replenish a considerable amount of refrigerant gas from the suction side of the compressor 2 (or from the gas holder 6).

Therefore, in preparation for this, the gas holder 6 needs to store a considerable amount of gas refrigerant at atmospheric pressure, so it is inevitably large and extremely expensive, and it also requires a large installation space. There are drawbacks.

The present invention has been made with attention to this point, and an object thereof is to provide a refrigeration system in which a gas holder for storing refrigerant gas when a compressor is started is miniaturized.

Furthermore, although FIG. 3 shows one embodiment of the present invention, the same reference numerals as those in the conventional system (FIG. 1) mentioned above refer to the same constituent members, and the explanation thereof will be omitted.

Reference numerals 12A and 12B are bypass valve devices that are connected in parallel across the discharge side and suction side of the compressor 2, respectively, and are made up of a plurality of electromagnetic valves that are opened when the compressor 2 is started. 12A.

12B is a flow rate regulating valve 13 which is set to a predetermined opening degree in advance.
A and 13B are connected in series.

Therefore, each of the above-mentioned bypass valve devices 12A.

12B are respectively connected to a control device 7 operated by a signal from the gas capacity detector 11 of the gas holder 6, and are sequentially closed by a signal from the control device 7 when the compressor 2 is started. , this compressor 2
At startup, the gas supply solenoid valve 8 is opened so that the refrigerant gas in the gas cylinder 10 is supplied to the gas holder 6.

Since the refrigeration system of the present invention is configured as described above, when the compressor 2 is started, its discharge pressure increases in three stages as shown in FIG. 4.

That is, in the first stage (between c and b in FIG. 4), since both bypass valve devices 12A and 12B are open, most of the discharged gas refrigerant flows through both bypass valve devices 1.
Bypassed by passing through 2A, 12B, 5
Equilibrium occurs at approximately atmospheric pressure (Figure 4, a-b).

Next, in the second stage (between b and c in FIG. 4), the gas holder 6
Since only one bypass valve device 12A is closed by the first full signal from the gas capacity detector 11,
The amount of bypass of the compressor 2 decreases, and the discharge pressure is balanced at about 10 atm (between c and d in Fig. 4).

Next, in the third stage (between d and e in Figure 4), the gas holder 6
The second full tank signal from the gas capacity detector 11 closes the other bypass valve device 12B, so the bypass amount of the compressor 2 becomes zero and rises to the normal operating level of 15 atmospheres (the fourth Figure e).

As described above, the refrigeration system of the present invention includes a plurality of bypass valve devices 12A spanning the discharge side and the suction side of the compressor 2.
, 12B are connected in parallel, and each bypass valve device 12A is activated by a signal from the gas capacity detector 11 of the gas holder 6 when the compressor 2 is started.

12B are closed in order to increase the discharge pressure of the compressor 2 in stages, so there is no need to replenish a large amount of gas refrigerant from the gas holder 6 when starting the compressor 2, unlike in conventional refrigeration systems of this type. However, by making the gas holder 6 smaller, there is an excellent effect of reducing cost and installation space.

In the above embodiment, a pair of bypass electromagnetic valves 12A and 12B are used as the bypass valve device, but it goes without saying that three or more valves may be used.

In addition, as the bypass valve device, instead of using only a plurality of solenoid valves, it is also possible to use a single automatic valve whose opening degree is automatically and steplessly adjusted based on the signal from the gas capacity detector 11 of the gas holder 6. It goes without saying that similar effects can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a piping diagram showing a conventional refrigeration system, and FIG. 2 is a discharge pressure characteristic diagram of a compressor in the conventional refrigeration system. FIG. 3 is a piping diagram showing an embodiment of the present invention, and FIG. 4 is a discharge pressure characteristic diagram of the compressor in the refrigeration system of the present invention. In the drawing, 1 is a refrigeration cycle, 2 is a compressor, 6 is a gas holder, 11 is a gas capacity detector, and 12A. 12B is a bypass valve device. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A compressor that compresses gas refrigerant, a pressure regulating valve connected across the discharge side and suction side of the compressor, and a pressure regulating valve connected to the discharge side and suction side of the compressor. In a refrigeration cycle comprising a refrigerator main body, a gas cylinder for storing gas refrigerant and replenishing the compressor, and a gas holder with a capacity detector connected to the suction side of the compressor, the discharge side of the compressor and a bypass valve device connected in parallel with the pressure regulating valve on the suction side, and the bypass valve device is controlled by a signal from the capacity detector of the gas holder when the compressor is started to control the discharge of the compressor. A refrigeration device characterized by increasing pressure in stages. 2. The refrigeration system according to claim 1, characterized in that a plurality of electromagnetic valves are used as the bypass valve device.