JP3031802B2 - Refrigeration equipment - Google Patents

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 shows, for example, a conventional refrigeration system, 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 sending liquid refrigerant to the apparatus 5, 6 an evaporator, 7 an injection circuit branched from the main liquid pipe 4, 8 a discharge gas pipe provided with a detected discharge gas temperature equal to or higher than a first predetermined temperature. And a discharge temperature switch 9 which operates when the temperature reaches a predetermined temperature and stops the compressor. The discharge temperature switch 9 is provided in the same discharge gas pipe and provided in the injection circuit 7 when the detected discharge gas temperature reaches a second predetermined temperature or higher. Injection temperature switches 10 and 11 for opening the switching device 13 are capillary tubes, 12 is a main switching device provided in the injection circuit 7, and is always open when the refrigerant compressor 1 is operating. . Reference numeral 14 denotes a compression chamber of the refrigerant compressor.

[0003] The conventional refrigeration system is configured as described above,
For example, high-temperature and high-pressure refrigerant compressed by the refrigerant compressor 1 is condensed and liquefied in 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 to be in a gas-liquid two-phase state, and is gasified by exchanging heat with the heat-exchanged air in the evaporator 6 and again. Return to the compressor and repeat the above cycle. In addition, main liquid piping 4
The injection circuit 7 branched from is connected to 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 increases,
The refrigerant is injected into the compression chamber 14 of the compressor 1. The temperature of the gas sucked into the refrigerant compressor 1 decreases due to the liquid refrigerant flowing through the injection circuit 7, and the discharge gas temperature and the oil temperature of the refrigerant compressor 1 decrease.

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 from the discharge gas pipe of the refrigeration system. When the discharge gas temperature of the refrigerant compressor 1 rises to a first predetermined temperature (135 ° C.), the discharge gas temperature switch 8 stops the operation to protect the internal components of the refrigerant compressor 1. In addition, the temperature switch for injection 9
Detects the temperature of the gas discharged from the refrigerant compressor 1 and, if the discharge temperature is higher than a second predetermined temperature (117 ° C.), opens the switchgear 13 to provide a circuit for allowing a larger amount of liquid refrigerant to flow therethrough; If it is lower, the switching device 13 is closed and the resistance is given by the capillary tube 11 so as to switch to a circuit in which a small flow rate flows.

[0005]

In the conventional refrigeration system as described above, a part of the liquid refrigerant is branched off from the liquid circuit to avoid an excessive rise in the discharge gas temperature and the oil temperature of the refrigerant compressor 1. Since the refrigerant is injected into the compression chamber 14 of the compressor 1, the amount of liquid in the liquid reservoir 3 changes due to a change 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 is reduced, the temperature of the discharge gas of the refrigerant compressor 1 increases, and the discharge gas temperature switch 8 may be operated to prevent proper operation. Also,
There is also a risk that oil in the refrigeration system will be severely deteriorated with an increase in the temperature of the discharge gas. In addition, the discharge gas temperature switch 8 and the injection temperature switch 9 are provided separately, and the discharge gas radiates heat to the outside air. Therefore, when the outside air temperature is extremely low and the refrigerant circulation amount is small, During the flow, the temperature drops and the temperature switch for injection 9
Until the detected temperature reaches the second predetermined temperature (117 ° C.), the discharge gas temperature switch 8 operates and the refrigerant compressor 1 may be stopped.

The present invention has been made to solve such a problem. Even if the amount of liquid refrigerant in a liquid reservoir changes due to a change in operating conditions or the like, an appropriate amount of refrigerant always remains in the compression chamber of the refrigerant compressor. It is an object of the present invention to obtain a refrigeration system that injects a liquid refrigerant and allows a refrigerant compressor to operate properly.

[0007]

In a refrigerating apparatus according to the present invention, a discharge gas temperature switch of a refrigerant compressor and an injector are provided.
Control the opening and closing of the switchgear provided in the
Set the mounting position of the temperature switch for injection to the discharge gas path.
They are mounted close to each other . Also vomit
Outlet gas temperature switch mounted near discharge gas path of compressor
Injection temperature switch for injection gas temperature switching
Ru der those mounted in proximity to the downstream vessels.

[0008] Further , the liquid refrigerant is taken out of the injection circuit.
The outlet is provided in the lower part of the liquid reservoir .

Further, a liquid refrigerant is supplied from the liquid reservoir to the expansion device.
Inject from the liquid refrigerant outlet in the liquid reservoir of the main liquid pipe.
With the liquid refrigerant outlet of the suction circuit at a lower position
It is .

[0010]

In the refrigerating apparatus configured as described above, the refrigerant pressure
Installed in the discharge gas temperature switch of the compressor and the injection circuit.
Injection temperature for opening and closing the gage switchgear
The switch is mounted close to the discharge gas path.
Large changes in outside air temperature and operating conditions
However, both temperature switches are always detecting the same discharge gas temperature.
To the continuously rising discharge gas temperature.
The injection temperature switch is activated first, and the discharge gas temperature
Suppress the rise .

Also, the liquid to be sent to the injection circuit
Refrigerant is taken out from the lower part of the reservoir to ensure refrigerant pressure
Since it can be injected into the compression chamber of the compressor,
Can be operated without abnormal stop .

[0012]

[Embodiment 1] FIG. 1 is a view showing an embodiment of the present invention. Conventionally, the injection circuit 7 branches from the main liquid pipe 4 and
In this embodiment, the liquid is taken out from the lower part of the liquid reservoir 3.

In the refrigeration system configured 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 The liquid refrigerant can be reliably injected into the refrigerant compressor 1 even if the surface changes. Therefore, an excessive rise in the discharge gas temperature can be avoided, the internal components in the refrigerant compressor 1 can be protected, and deterioration of the oil in the refrigerating device can be suppressed. Then, an appropriate operation state can be secured without abnormally stopping the refrigeration apparatus.

Embodiment 2 FIG. In the first embodiment, the liquid refrigerant outlet 7a of the injection circuit 7 is provided in the lower portion of the liquid reservoir 3, so that even if the amount of liquid refrigerant (liquid level) in the liquid reservoir changes due to a change in operating conditions, etc. Although the structure is such that the liquid refrigerant can be injected into the refrigerant compressor 1, as shown in FIG. 2, the liquid refrigerant in the main liquid pipe 4 that supplies the liquid refrigerant from the liquid reservoir 3 of the main refrigerant circuit to the expansion device 5 is provided. Similar functions and effects can be expected even if the liquid refrigerant outlet 7a of the injection circuit 7 is provided at a position lower than the liquid refrigerant outlet 4a.

Embodiment 3 FIG. FIG. 3 is a view showing an embodiment in which the discharge gas temperature switch 8 and the injection temperature switch 9 are mounted close to the vicinity of the discharge gas path of the compressor 1. In this example,
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, and serves to stop the compressor 1 to protect it. The injection temperature switch 9 is linked with the switch 13, and opens and closes when the discharge gas temperature of the refrigerant compressor 1 reaches about 117 ° C. or more as the second predetermined temperature.
At a temperature of 17 ° C. or lower, the opening / closing device 13 functions to be closed. That is, when the discharge gas temperature is relatively high, the opening and 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 and closing device 13 is closed to reduce the flow rate of the liquid refrigerant. I am trying to do it. A refrigerating apparatus has a wide operating range, for example, about -45 ° C to + 10 ° C in terms of evaporation temperature. Therefore, when the refrigerant circulation amount is small such as the evaporation temperature is −45 ° C. and the condensing temperature is 40 ° C., the discharge gas temperature rises compared with the case where the refrigerant circulation amount is high when the evaporation temperature is high, and the discharge gas temperature switch 8
Approaches the operating area. 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 in the circuit. Therefore, when the outside air temperature is low, the temperature detected by the injection temperature switch 9 is 1
The temperature does not reach 17 ° C., and the opening / closing device 13 is not opened. Therefore, a sufficient amount of liquid refrigerant to lower the discharge temperature cannot be injected into the refrigerant compressor 1, and the discharge gas temperature switch 8 operates earlier and stops the compressor. Therefore, in the vicinity of the discharge gas passage of both temperature switch, by attaching each proximity to, also, the discharge gas temperature
Install a switch near the discharge gas path of the compressor,
Near the downstream of the discharge gas temperature switch
By mounting in contact with each other, each temperature switch always detects substantially the same discharge gas temperature, and the temperature switch for injection always has a low operating temperature in the process of increasing the discharge gas temperature. 9 operates first to make the injection circuit 7 function, so that the operation of the refrigerant compressor can be continued without abnormal stop.

[0016]

According to the refrigerating apparatus of the present invention, the discharge gas
Gas discharge temperature switch and temperature switch for injection
Provision of operating conditions by providing
Changes in the discharge gas temperature
As the temperature rises, both temperature switches always have the same discharge gas temperature.
Is detected, the injection temperature is low.
The temperature switch for the gasket operates properly first,
Suppress excessive temperature rise of the compressor to prevent abnormal stop of the refrigerant compressor
To prevent deterioration of the refrigerating machine oil and to improve the reliability of the refrigerant compressor.
It is possible to maintain high quality .

Also, the liquid refrigerant is taken out of the injection circuit.
By setting the outlet at the bottom of the liquid reservoir, always use the proper amount of liquid cooling.
Medium can be injected into the compression chamber of the refrigerant compressor, and
Stable operation without stopping the refrigeration system abnormally
Can be .

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of a refrigeration apparatus 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 refrigeration apparatus according to Embodiment 2 of the present invention.

FIG. 3 is a mounting diagram of a discharge temperature switch and an injection temperature switch provided in a discharge gas passage (discharge gas pipe) of a refrigeration apparatus according to Embodiment 3 of the present invention.

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

[Explanation of symbols]

REFERENCE SIGNS LIST 1 refrigerant compressor, 2 condenser, 3 liquid reservoir, 4 main liquid pipe, 4a main liquid pipe, 4 liquid refrigerant outlet, 5 throttle device, 6 evaporator, 7 injection circuit, 7a liquid refrigerant discharge from 7a injection circuit 7 Mouth, 8 discharge gas temperature switch, 9 injection temperature switch, 10,
11 Capillary tube, 13 Opening / closing device, 14 Compression chamber of compressor.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-116345 (JP, A) JP-A-2-5313 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 1/00 311 F25B 43/00 F25B 49/02 510

Claims (4)

(57) [Claims] 1. A main refrigerant circuit comprising a refrigerant compressor, a condenser, a liquid reservoir containing a liquid refrigerant condensed by the condenser, a throttle device, and an evaporator; and a refrigerant circuit condensing the liquid refrigerant condensed by the condenser. In a refrigeration system having an injection circuit for injecting the refrigerant into a compression chamber of the compressor, the detected discharge gas of the refrigerant compressor is provided.
When the compressor temperature rises above the first predetermined temperature,
Discharge gas temperature switch to stop operation and detected discharge
The gas temperature is equal to or higher than a second predetermined temperature lower than the first predetermined temperature
The switchgear provided in the injection circuit is opened
Temperature switch for injection
The switch position near the discharge gas path of the compressor.
A refrigeration device which is mounted close to each other . 2. A main refrigerant circuit comprising a refrigerant compressor, a condenser, a liquid reservoir for containing the liquid refrigerant condensed by the condenser, a throttle device, and an evaporator; and a refrigerant for condensing the liquid refrigerant condensed by the condenser. In a refrigeration system having an injection circuit for injecting the refrigerant into a compression chamber of the compressor, the detected discharge gas of the refrigerant compressor is provided.
When the compressor temperature rises above the first predetermined temperature,
Discharge gas temperature switch to stop operation and detected discharge
The gas temperature is equal to or higher than a second predetermined temperature lower than the first predetermined temperature
The switchgear provided in the injection circuit is opened
Temperature switch for injection
A gas temperature switch is installed near the discharge gas path of the compressor.
The temperature switch for injection to the discharge gas
A refrigeration apparatus, which is mounted adjacent to and downstream of a temperature switch . 3. A liquid refrigerant discharge of said injection circuit.
2. A spout is provided below the liquid reservoir.
Or the refrigeration apparatus according to 2 . 4. A liquid refrigerant discharge of said injection circuit.
Provide a spout in the reservoir and squeeze it from the reservoir.
From the liquid refrigerant outlet of the main liquid pipe that supplies liquid refrigerant to the
3. The device according to claim 1, wherein the device is provided at a low position.
On-board refrigeration equipment .