JPS59197762A - Refrigeration cycle - 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 a refrigeration cycle used in, for example, quick-freezing refrigerators.

FIG. 1 is a circuit diagram of a refrigeration cycle used in a conventional quick-freezing refrigerator. In the figure, 1 is a compressor, 2 is a condenser, 3a is a first pressure reducing device, 3b is a second pressure reducing device, 4 is a solenoid valve connected in parallel to the first pressure reducing device 3a, and 5 is an evaporator. are shown respectively. This circuit has a single refrigerant,
For example, the refrigerant is filled with R12 having a boiling point of 130°C, and the arrow shown in the figure indicates the direction in which the refrigerant flows.

By the way, in a quick-freezing refrigerator, it is necessary to obtain an extremely low temperature of 140°C to -50°C during quick freezing and refrigeration, and a low temperature of 115°C to -20°C during normal freezing and refrigeration.

In the conventional refrigeration cycle having the above configuration, when the solenoid valve 4 is opened, the refrigerant gas that has become high temperature and high pressure in the compressor 1 is cooled by condensation 2 and liquefied. Thereafter, since the electromagnetic valve 4 is open, the refrigerant liquid does not pass through the first pressure reducing device 3a, but is directed to the second pressure reducing device 3b, where it is brought to a low temperature and low pressure and is led to the evaporator 5. When the refrigerant liquid is gasified in this evaporator 5, it absorbs heat from the surroundings and the temperature ranges from 0°C to -159°C.
Perform normal freezing. The refrigerant gas is then sucked into the compressor 1.

Next, when the electromagnetic valve 4 is closed, the refrigerant gas heated to high temperature and pressure by the compressor 1 is cooled by the condenser 2 and liquefied, as described above. After this, each of the first and second pressure reducing devices 3 a
Due to the action of + and 3b, the temperature and pressure become lower than in the above-mentioned case J), and the temperature is led to the evaporator 5. At this time, an ultra-low temperature of -40°C to -50°C is obtained.

As described above, in a refrigeration cycle such as a conventional quick-freezing refrigerator, during quick-freezing operation, the solenoid valve 4 is closed to further reduce the pressure of the refrigerant than during normal freezing operation, thereby bringing the refrigerant into a low-temperature state. However, as the temperature of the refrigeration cycle fd becomes lower, the pressure usually decreases, and the refrigeration capacity generally tends to decrease. Therefore, if an optimal single refrigerant (pure refrigerant mixture or azeotropic mixed refrigerant) is selected during normal refrigeration operation, the refrigeration capacity is insufficient during rapid refrigeration operation, resulting in a drawback that rapid refrigeration is difficult to achieve.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and in a refrigeration cycle having a condenser and a pressure reducing device, a branch pipe is provided to connect both the devices,
This branch pipe is equipped with a second pressure reducing device to fill the non-azeotropic mixed refrigerant to obtain a refrigerating cycle with high refrigerating capacity over a wide range of refrigerating temperatures.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows an embodiment of the present invention, in which 3a and 3b are first and second pressure reducing devices connected in parallel with each other, 6 is a refrigerant container, and the outlet of the condenser 2 is shown in FIG. A pipe from the pipe passes through the refrigerant container 6, and this pipe is separated at the lower part of the refrigerant container 6 to form a main pipe 2° and a main pipe 21, so that the refrigerant in the pipe flows out into the refrigerant container 6. 22 is the outlet of the condenser 2, the outlet of the first pressure reducing device 3a, and f:
A second pressure reducing device 3b is arranged in parallel with the first pressure reducing device 3a through a connecting branch pipe. 7 is the main manager 2 above
This is a solenoid valve provided downstream from the branch point of the branch pipe 22 of No. 0.

In the refrigeration cycle configured as above, 1f-7
j A non-azeotropic mixed refrigerant consisting of, for example, R12 having an astigmatism of 130° C. as a boiling point component and R13 having a boiling point of 181° C. as a low boiling point component is sealed. During ultra-low temperature operation, the solenoid valve 7 is closed. As a result, the circuit downstream of the electromagnetic valve 7 is cut off, and the non-azeotropic mixed refrigerant gas compressed by the compressor 1 is condensed and liquefied in the condenser 2, and is further transferred to the second pressure reducing device 3.
It is depressurized at step b, enters the evaporator 5, evaporates, becomes gas again, and returns to the compressor 1. With this kind of operation, Q'', evaporator 5
Since the boiling point of Ri, 3 is as low as 181° C. when evaporated inside the reactor, ultra-low temperatures can be obtained with a relatively high evaporation pressure using this non-azeotropic refrigerant mixture.

Next, during normal operation, when the solenoid valve 7 is opened, the non-azeotropic mixed refrigerant is compressed by the compressor 1 and condensed by the condenser 2 in the same manner as described above. Here, since the condensation temperatures of R12 and R13 are different, a liquid rich in R12 components and a gas rich in R13 components coexist. A part of the refrigerant flowing out from the condenser 2 enters the refrigerant container 6. Here, the gas rich in R13 components remains in the upper part of the refrigerant container 6, and only the liquid rich in R12 components is depressurized by the first pressure reducing device 3a and enters the evaporator 5.
It evaporates and returns to compressor 1. By repeating this process, R13 remains as a gas in the upper part of the refrigerant container 6, and substantially pure R12 alone circulates in the refrigeration cycle. Therefore, by evaporating R12 at this time, a temperature of -15°C to -20°C can be obtained with substantially the same evaporation pressure as in the ultra-low temperature operation. After normal refrigeration operation, when the electromagnetic valve 7 is closed and ultra-low temperature operation is performed, the gas rich in R13 components remaining in the refrigerant container 6 due to the pressure difference passes through the first pressure reducing device 3a and is returned to the refrigeration cycle. .

According to an embodiment of the present invention, during rapid cooling, a non-azeotropic mixed refrigerant of R12 and R13 is used, and during normal refrigeration, R13' (il-confined, R1
By using a single refrigerant, the evaporation pressures of both refrigerants can be kept approximately the same, and a wide range of temperatures can be obtained without reducing the refrigerating capacity.

Moreover, as shown in FIG. 3 as another embodiment of the present invention,
A first electromagnetic valve 7a is provided on the inlet side of the refrigerant container 6, and a second electromagnetic valve 7b is provided in the branch pipe 22 upstream of the second pressure reducing device 3b. By operating this second solenoid valve 7b to open during ultra-low temperature operation and close during normal refrigeration operation, the non-boiling mixed refrigerant flows through the second pressure reducing device 3b during ultra-low temperature operation, and the second electromagnetic valve 7b during normal refrigerant operation. Since the refrigerant does not flow to the pressure reducing device 3b but flows through the first pressure reducing device 3a, the high boiling point refrigerant and the low boiling point refrigerant can be efficiently separated.

In this embodiment, since the pressure reducing device used in each operation is different, the pressure reducing device can be easily designed. .

As a further embodiment of the present invention, as shown in FIG. 4, a third electromagnetic valve 7C is provided in the evaporator 5, and is closed when the operation is stopped and opened when the operation is stopped.

In the conventional example, when the operation is stopped, the refrigerant in the condenser 2 and the refrigerant container 6 flows into the evaporator 5 due to the pressure difference, but due to the action of the third electromagnetic valve 7C, the refrigerant does not flow into the evaporator 5 when the operation is stopped. , 0, which is kept in the state it was in before the operation was stopped.
As a result, when the normal refrigeration operation is stopped and the normal refrigeration operation is resumed, stable operation is possible because the high boiling point refrigerant and the low boiling point refrigerant are already separated. In addition, there is also the effect of preventing load on the compressor 1.

On the other hand, as shown in FIG. 5, the refrigerant container 6'! The penetrating main pipe 20 may be placed in the upper part.Also, as shown in FIG. The non-azeotropic refrigerant mixture is not limited to R1, 2 and R13, but may also include other high-boiling refrigerants and low-boiling refrigerants. The same effect can be expected even if the mixture is mixed.In addition, the main pipe 20.21 (d division) that penetrates inside the refrigerant container 6 has a 1" T configuration, but instead of this, -) j place hole '71: l; made] (can be made into i/f composition, cooled to 1 of cold N container 6) j, t: is?71.
3. “~Le Z deao L (the above”:”:
I'm looking forward to the same effect as //iQ Shi1].

That’s it! 7. According to the present invention, in a refrigeration cycle having a pressure reducing device, a refrigerant container is provided, and a 4" main pipe from the outlet of the condenser passes through the refrigerant container, and the lower part of the inside of the nuclear refrigerant container. A solenoid valve is connected between the condenser and the refrigerant, and is connected between the condenser outlet and the refrigerant outlet.
- A branch 6 Hz connecting the above pressure reducing device outlet and a second pressure reducing device 1a connected in the middle of the above branch pipe are provided to provide sufficient refrigerating capacity with the non-azeotropic mixture low temperature and 1i + room temperature. 4
4 It has the practical effect of being a dog.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a conventional refrigeration cycle using a single refrigerant, FIG. 2 is a circuit diagram showing a refrigeration cycle according to Example A, in which a part of the present invention is implemented, and FIG. 3 is a circuit diagram showing another embodiment of the present invention. 1+l
No. 41 is a circuit diagram showing a refrigeration cycle according to still another embodiment of the present invention, and FIGS. 5 and 6 are a circuit diagram showing a refrigerating cycle according to still another embodiment of the present invention. FIG. DESCRIPTION OF SYMBOLS 1... Compressor, 2... Condenser, 3a, 3b... Pressure reduction device, 5... Evaporator, 6... Refrigerant container, 7, 7a,
7b. 7c... Solenoid valve, 8... Fractional distillation filling, 20.21
...Main pipe, 22... Branch pipe. In the figures, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa Figure 1 Figure 2 Figure 3

Claims (4)

[Claims] (1) In a refrigeration cycle in which a compressor, a condenser, a pressure reducing device, and an evaporator are sequentially connected, and the outlet of the evaporator is connected to the inlet of the compressor, a refrigerant container is provided, and A main pipe passes through the refrigerant container and opens at least one place in the lower part of the refrigerant container, and includes a solenoid valve connected between the condenser and the refrigerant container, and a solenoid valve connected between the condenser outlet and the refrigerant container. A refrigeration cycle characterized in that a branch pipe connecting an outlet of a pressure reducing device and a second pressure reducing device connected in the middle of the branch pipe are provided, and the refrigeration cycle is filled with a non-azeotropic mixed refrigerant. (2) Refrigeration cycle 0 according to claim 1, characterized in that a second solenoid valve is provided in the branch pipe. (3) The refrigeration cycle according to claim 1 or 2, characterized in that a third solenoid valve is provided at the evaporator inlet. (4) The refrigeration cycle according to claim 1, 2, or 3, characterized in that a fractionating filler is inserted into the container.