JPH07133964A - Refrigerating apparatus - Google Patents

Abstract

PURPOSE:To provide a refrigerating apparatus, in which a proper amount of liquid refrigerant can always be poured into a compression chamber in a refrigerant compressor and the refrigerant compressor can operate properly even when an amount of liquid refrigerant in a liquid reservoir is varied due to a change in an operating condition. CONSTITUTION:Provided in a lower portion in a liquid reservoir 3 is a liquid refrigerant takeoff port 7a of an injection circuit 7 whereby a liquid refrigerant can be positively poured into a refrigerant compressor 1 even when an amount of liquid refrigerant in the liquid reservoir is varied due to a change in an operating condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvements in refrigerators used in supermarkets, refrigerators, freezers and the like.

[0002]

2. Description of the Related Art FIG. 4 is a view showing, for example, a conventional refrigerating apparatus, in which 1 is a refrigerant compressor, 2 is a condenser, 3 is a liquid reservoir for containing a liquid refrigerant, and 4 is a throttle from the liquid reservoir 3. A main liquid pipe for delivering a liquid refrigerant to the device 5, 6 is an evaporator, 7 is an injection circuit branched from the main liquid pipe 4, 8 is a discharge gas pipe, and the detected discharge gas temperature is equal to or higher than a first predetermined temperature. A discharge temperature switch that operates when the temperature reaches a predetermined value and stops the compressor, and 9 is provided in the same discharge gas pipe and provided in the injection circuit 7 when the detected discharge gas temperature reaches or exceeds the second predetermined temperature. An injection temperature switch for opening the switch device 13, 10 and 11 are capillary tubes, 12 is a main switch device provided in the injection circuit 7, and is always open when the refrigerant compressor 1 is operating. . Reference numeral 14 is a compression chamber of the refrigerant compressor.

The conventional refrigeration system is constructed as described above,
For example, the high-temperature and high-pressure refrigerant compressed by the refrigerant compressor 1 is condensed and liquefied by the condenser 2, and the liquid refrigerant is stored in the liquid reservoir 3.
The liquid refrigerant sent from the liquid reservoir 3 through the main liquid pipe 4 is decompressed by the expansion device 5 into a gas-liquid two-phase state, and is heat-exchanged with the heat-exchanged air in the evaporator 6 to be gasified, and again. Return to the compressor and repeat the above cycle. In addition, the main liquid piping 4
The injection circuit 7 branched from is communicated with the inside of the compression chamber 14 of the refrigerant compressor 1 via the capillary tubes 10 and 11. The liquid refrigerant flowing through the injection circuit 7 is decompressed by the capillary tube 10 or the capillary tubes 10 and 11, becomes a low-pressure gas-liquid two-phase refrigerant, exchanges heat with the surrounding air, and the dryness of the refrigerant becomes high.
It is injected into the compression chamber 14 of the refrigerant compressor 1. The temperature of the gas sucked into the refrigerant compressor 1 is lowered by the liquid refrigerant flowing through the injection circuit 7, and the discharge gas temperature and the oil temperature of the refrigerant compressor 1 are lowered.

A discharge gas temperature switch 8 and an injection temperature switch 9 for controlling the opening and closing of the injection circuit 7 are provided separately in the discharge gas pipe of the refrigeration system. The discharge gas temperature switch 8 functions to stop the operation of the refrigerant compressor 1 in order to protect the internal components of the refrigerant compressor 1 when the discharge gas temperature of the refrigerant compressor 1 rises to a first predetermined temperature (135 ° C.). In addition, the temperature switch for injection 9
Detects the discharge gas temperature of the refrigerant compressor 1, and when the discharge temperature is higher than the second predetermined temperature (117 ° C.), opens the switch device 13 to form a circuit in which a large amount of liquid refrigerant flows, If it is lower, the opening / closing device 13 is closed and resistance is given by the capillary tube 11 to switch to a circuit in which a small flow rate flows.

[0005]

In the conventional refrigerating apparatus as described above, in order to prevent the discharge gas temperature and the oil temperature of the refrigerant compressor 1 from rising excessively, a part of the liquid refrigerant is branched off from the liquid circuit. Since the liquid is injected into the compression chamber 14 of the compressor 1, the amount of liquid in the liquid reservoir 3 changes due to changes in operating conditions and the like, and the amount of refrigerant flowing through the main liquid pipe 4 decreases. When the amount of the refrigerant to be injected into the chamber 14 decreases, the discharge gas temperature of the refrigerant compressor 1 rises, and the discharge gas temperature switch 8 may operate to prevent proper operation. Also,
There is also a possibility that the oil inside the refrigeration system may be severely deteriorated as the discharge gas temperature rises. Further, since the discharge gas temperature switch 8 and the injection temperature switch 9 are installed separately from each other, the discharge gas radiates heat to the outside air so that the outside air temperature is extremely low and the refrigerant circulation amount is small, the inside of the pipe is During the flow, the temperature drops and the injection temperature switch 9
The discharge gas temperature switch 8 is activated and the refrigerant compressor 1 may be stopped before the detected temperature reaches the second predetermined temperature (117 ° C.).

The present invention has been made in order to solve such problems, and even if the amount of liquid refrigerant in the liquid reservoir changes due to changes in operating conditions, etc., an appropriate amount is always provided in the compression chamber of the refrigerant compressor. It is an object of the present invention to obtain a refrigerating device that can inject a liquid refrigerant and can operate the refrigerant compressor properly.

[0007]

In the refrigerating apparatus according to the present invention, the liquid refrigerant outlet of the injection circuit is provided in the lower part of the liquid reservoir.

Further, the liquid refrigerant outlet of the injection circuit is provided at a position lower than the liquid refrigerant outlet of the liquid reservoir of the main liquid pipe for supplying the liquid refrigerant from the reservoir to the expansion device.

Further, the discharge gas temperature switch of the refrigerant compressor and the injection temperature switch for controlling the opening and closing of the switch device provided in the injection circuit are mounted in the vicinity of the discharge gas passage.

[0010]

In the refrigerating apparatus configured as described above, the liquid refrigerant to be sent to the injection circuit can be reliably injected into the compression chamber of the refrigerant compressor by taking out the liquid refrigerant from the lower part of the liquid reservoir. You can drive without letting it go.

Further, by mounting a discharge gas temperature switch of the refrigerant compressor and an injection temperature switch for controlling the opening and closing of the switch provided in the injection circuit in the vicinity of the discharge gas passage, a large change in the outside air temperature,
Even if there is a change in operating conditions, both temperature switches are always detecting the same discharge gas temperature, and the injection temperature switch operates accurately first against the continuously rising discharge gas temperature. Suppress the rise in discharge gas temperature.

[0012]

【Example】

Example 1. FIG. 1 is a diagram showing an embodiment of the present invention,
1 to 14 are exactly the same as the above-mentioned conventional device. The injection circuit 7 has conventionally been branched from the main liquid pipe 4 and communicated with the refrigerant compressor 1. However, in this embodiment, the injection circuit 7 is taken out from the lower part inside the liquid reservoir 3.

In the refrigerating apparatus constructed as described above, the liquid refrigerant outlet 7a of the injection circuit 7 is provided below the liquid reservoir 3, so that the amount of liquid refrigerant in the liquid reservoir (liquid Even if the (face) changes, the liquid refrigerant can be surely injected into the refrigerant compressor 1. Therefore, it is possible to prevent the discharge gas temperature from rising excessively, protect the internal components in the refrigerant compressor 1, and suppress the deterioration of the oil in the refrigeration system. And an appropriate operating state can be secured without abnormally stopping the refrigeration system.

Example 2. In the first embodiment, since the liquid refrigerant outlet 7a of the injection circuit 7 is provided in the lower portion of the liquid reservoir 3, even if the amount of liquid refrigerant (liquid level) in the liquid reservoir changes due to a change in operating conditions or the like, it is possible to reliably perform the operation. The structure is such that the liquid refrigerant can be injected into the refrigerant compressor 1.
As described above, the liquid refrigerant outlet port 4 in the liquid reservoir portion of the main liquid pipe 4 for supplying the liquid refrigerant from the liquid reservoir 3 of the main refrigerant circuit to the expansion device 5
Even if the liquid refrigerant outlet 7a of the injection circuit 7 is provided at a position lower than a, the same action and effect can be expected.

Example 3. FIG. 3 is a view showing an embodiment in which the discharge gas temperature switch 8 and the injection temperature switch 9 are mounted near the discharge gas passage of the compressor 1 in the vicinity thereof.
In this embodiment, when the discharge gas temperature of the refrigerant compressor 1 reaches about 135 ° C. as the first predetermined temperature, the discharge gas temperature switch 8 operates to stop the compressor 1 in order to protect it. To do. Further, the injection temperature switch 9 is linked to the switch device 13, and opens the switch device 13 when the discharge gas temperature of the refrigerant compressor 1 is about 117 ° C. or higher as the second predetermined temperature, and opens the switch device at 117 ° C. or lower. It works like closing 13. That is, when the discharge gas temperature is relatively high, the opening / closing device 13 is opened to increase the flow rate of the liquid refrigerant to lower the discharge gas temperature, and when the discharge gas temperature is relatively low, the opening / closing device 13 is closed to reduce the liquid refrigerant flow rate. I am trying to do it. The operating range of the refrigeration system is wide, and for example, the evaporation temperature is about -45 ° C to + 10 ° C. Therefore, in the case where the refrigerant circulation amount such as the evaporation temperature is −45 ° C. and the condensation temperature is 40 ° C., the discharge gas temperature rises as compared with the case where the evaporation temperature is high and the refrigerant circulation amount is large, and the discharge gas temperature switch 8 Approaches the area where On the other hand, at this time, the high temperature gas discharged from the refrigerant compressor 1 radiates heat to the outside air when flowing through the circuit. Therefore, when the outside air temperature is low, the temperature detected by the injection temperature switch 9 is The temperature does not reach 117 ° C., and the opening / closing device 13 is not opened. Therefore, a sufficient amount of liquid refrigerant for lowering the discharge temperature cannot be injected into the refrigerant compressor 1, and the discharge gas temperature switch 8 may operate earlier and the compressor may stop. Therefore, by installing both temperature switches near the discharge gas path, respectively,
Since each temperature switch always detects substantially the same discharge gas temperature, the injection temperature switch 9 having a low operating temperature is inevitably in the process of increasing the discharge gas temperature.
Operates earlier to cause the injection circuit 7 to function, so that the operation can be continued without abnormal stoppage of the refrigerant compressor.

[0016]

EFFECTS OF THE INVENTION By making the liquid refrigerant outlet of the injection circuit the lower part of the liquid reservoir, a proper amount of liquid refrigerant can be constantly injected into the compression chamber of the refrigerant compressor, and the refrigeration system can be stopped abnormally. It is possible to drive stably without.

Further, the discharge gas temperature switch and the injection temperature switch are provided close to the vicinity of the discharge gas passage, so that the discharge gas temperature rises sequentially even if the operating conditions change or the outside air temperature changes. Both temperature switches always detect the same discharge gas temperature during the process, and the injection temperature switch with a low operating temperature operates accurately first to suppress the excessive rise in discharge gas temperature. Then
The refrigerant compressor is prevented from abnormally stopping and the refrigerating machine oil is prevented from being deteriorated to maintain high reliability of the refrigerant compressor.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram of a refrigeration system according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a positional relationship among a liquid reservoir, a main liquid pipe, and an injection circuit of a refrigerating apparatus according to Embodiment 2 of the present invention.

FIG. 3 is a mounting view of a discharge temperature switch and an injection temperature switch provided in a discharge gas passage (discharge gas pipe) of a refrigeration system according to a third embodiment of the present invention.

FIG. 4 is a refrigerant circuit diagram of a conventional refrigeration system.

[Explanation of symbols]

 1 Refrigerant Compressor 2 Condenser 3 Liquid Reservoir 4 Main Liquid Pipe 4a Liquid Refrigerant Outlet of Main Liquid Pipe 4 5 Throttle Device 6 Evaporator 7 Injection Circuit 7a Liquid Refrigerant Outlet of Injection Circuit 7 8 Discharge Gas Temperature Switch 9 Injection Temperature switch 10, 11 Capillary tube 13 Switchgear 14 Compressor compression chamber

Claims (3)

[Claims] 1. A main refrigerant circuit comprising a refrigerant compressor, a condenser, a liquid reservoir for accommodating the liquid refrigerant condensed by the condenser, an expansion device, and an evaporator, and a liquid refrigerant condensed by the condenser. A refrigerating apparatus having an injection circuit for injecting into a compression chamber of a compressor, wherein the liquid refrigerant outlet of the injection circuit is provided in the lower portion of the liquid reservoir. 2. A main refrigerant circuit comprising a refrigerant compressor, a condenser, a liquid reservoir for accommodating the liquid refrigerant condensed by the condenser, an expansion device, and an evaporator, and a liquid refrigerant condensed by the condenser. In a refrigerating apparatus having an injection circuit for injecting into the compression chamber of a compressor, a liquid refrigerant outlet of the injection circuit is provided in the liquid reservoir, and the liquid of the main liquid pipe that supplies the liquid refrigerant to the expansion device from the liquid reservoir. A refrigerating device provided at a position lower than a refrigerant outlet. 3. A main refrigerant circuit comprising a refrigerant compressor, a condenser, a liquid reservoir for accommodating the liquid refrigerant condensed by the condenser, a throttle device, and an evaporator, and a liquid refrigerant condensed by the condenser. In a refrigeration system equipped with an injection circuit for injecting into a compression chamber of a compressor, a discharge gas temperature opening and closing that operates when the detected discharge gas temperature of the refrigerant compressor exceeds a first predetermined temperature and stops the operation of the compressor. And a temperature switch for injection that opens the switch device provided in the injection circuit when the detected discharge gas temperature becomes equal to or higher than a second predetermined temperature that is lower than the first predetermined temperature. The refrigerating apparatus is characterized in that the respective positions are mounted close to the vicinity of the discharge gas passage.