JPS6120798B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides that the non-azeotropic mixed refrigerant is
The present invention relates to refrigerators, and particularly to a defrosting device for this freezer/refrigerator.

Conventionally, as shown in FIGS. 1 and 2, this type of freezer/refrigerator condenses refrigerant compressed by a compressor a through heat exchange in a condenser b, and transfers this liquid refrigerant to a capillary reach tube. The refrigerant is evaporated and cooled in the evaporators f and g disposed in the refrigerator compartment d and the freezer compartment e through a pressure regulator (throttle mechanism) c, etc., and the refrigerant that has completed its work is returned to the compressor a. I'm starting to do that.

However, the freezer compartment e of this type of freezer/refrigerator has an evaporator g disposed on the inner circumferential wall surface _e1 , and further,
Since the defrosting heater h is provided, the frost that has formed on the entire circumferential wall of the inner circumferential wall surface _e1 is defrosted by the defrosting heater h, so that the frost that has formed on the entire circumferential wall of the inner circumferential wall surface _e1 is defrosted. It is necessary to defrost the refrigerator by heating it over a period of time, and this causes the temperature of the freezer compartment e to rise, causing a decrease in the refrigeration efficiency.

In view of the above-mentioned points, the present invention utilizes the characteristics of a non-azeotropic mixed refrigerant (hereinafter simply referred to as mixed refrigerant) and the local low-temperature generation characteristics of frost, and arranges two evaporators with different temperatures in the freezing compartment. The frost that has formed on the high temperature evaporator is transferred to the low temperature evaporator by sublimation, where it is collected and defrosted using a heater, thereby eliminating the need to heat the entire wall surface of the freezer compartment. A refrigeration system that aims to improve refrigeration efficiency by
There is a refrigerator provided.

Hereinafter, the present invention will be described with reference to an illustrated embodiment.

In FIGS. 3 to 4, reference numeral 1 denotes the main body of a freezer/refrigerator incorporating a refrigeration cycle using a mixed refrigerant, and a refrigerating compartment 2 and a freezing compartment 3 are formed in the main body 1. Doors 4 and 5 are hinged to the openings of the refrigerator compartment 2 and the freezer compartment 3 so as to be openable and closable. Further, a compressor 6 is installed at the lower part of the outer side of the main body 1, and the mixed refrigerant pressurized by the compressor 6 is discharged into a discharge pipe (refrigerant pipe) as shown in FIG. The refrigerant is transferred from the refrigerant 7 to the condenser 8, where it undergoes heat exchange and becomes a two-phase flow refrigerant. Further, the two-phase flow refrigerant in the condenser 8 is separated into gas refrigerant and liquid refrigerant by a gas-liquid separator 9, and this gas refrigerant is sent to the first heat exchanger 11 through the pneumatic pipe 10. The above gas-liquid separator 9
The separated liquid refrigerant is transferred to a first throttling mechanism (pressure regulator) 13 disposed on the liquid feed pipe 12, a freezing evaporator 14 disposed within the freezing compartment 3, and a freezing evaporator 14 disposed within the refrigerating compartment 2. The heat is exchanged with the first heat exchanger 11 through the refrigerating evaporator 15, and then sent out. Further, the first heat exchanger 11 exchanges heat between the gas refrigerant and the two-phase refrigerant, and the gas refrigerant is liquefied by removing heat from it by the evaporation action of the liquid refrigerant. Further, the evaporated and gasified refrigerant returns directly to the supply port 6a of the compressor 6 through the reflux pipe 16, but the remaining liquefied refrigerant passes through the continuous pipe 17 to the second heat exchanger 18 and the second throttle. It is sent to a low temperature evaporator 20 through a mechanism 19, and is sent to each of the above-mentioned evaporators 14, 15.
It is designed to be cooled to a lower temperature. Since the refrigerant after heat exchange in the low-temperature evaporator 20 is still at a low temperature, it is returned to the second heat exchanger 18 through the connecting pipe 21 and exchanges heat with the liquid refrigerant to subcool the liquid refrigerant. After increasing the temperature, the refrigerant becomes a gas refrigerant and is returned to the compressor 6 through a return pipe 22 connected to the return pipe 16. Note that a defrosting heater 23 is provided near the low-temperature evaporator 20, and these are disposed within the freezer compartment 3.

Thus, for example, R ₁₃ versus R ₁₂ as a mixed refrigerant.
When mixed at a weight ratio of about 40%, if the outlet temperature of the condenser 8 is about 35°C and the inlet temperature of the low-temperature evaporator 20 is about -40°C, the i- It is represented by a p-diagram. The condensation pressure is approximately
23ata, evaporation pressure about 2ata, the above low temperature evaporator 20
The average evaporation temperature of the refrigerating evaporator 14 is about -35°C, and the average evaporation temperature of the freezing evaporator 14 is about -25°C.

On the other hand, if the temperature of the low-temperature evaporator is controlled to be approximately -35°C, and the average evaporation temperature of the freezing evaporator 14 is controlled to be approximately -25°C, the air inside the refrigerator will be This replaces the high temperature outside air, and the internal air temperature becomes approximately 25℃. In this case, because there is a large temperature difference between the evaporator 14 in chamber 3 and the inflowing air, the evaporator 14 and low-temperature evaporator 20 are frosted in the same way, but the frost increases and the temperature in chamber 3 decreases. When the temperature becomes stable, the freezing evaporator 1 whose temperature is higher than that of the low-temperature evaporator 20 due to the temperature difference between the frosted surfaces of the low-temperature evaporator 20 and the freezing evaporator 14
4, frost moves to the low-temperature evaporator 20 due to a diffusion phenomenon and forms frost.

That is, G=ρ _D 1/1−w·dw/dy.

However, G is the amount of movement of frost (Kg/m ² h), ρ is the specific gravity of humid air (Kg/m ³ ), D is the diffusion coefficient (m ³ /h), w is the absolute humidity of humid air, and y is cooling. Let the representative length between surfaces be (m).

Note that the cooling area A of the low temperature evaporator 20 is 0.04.
Assuming that m ² , the relationship between the temperature difference on the cooling surface and the amount of frost movement is shown by the graph in FIG. 6 using the above equation.

Also, if the temperature difference is about -10℃, the amount of frost transferred per day is about 100g, and the amount of frost formed per day is about
Since the amount is about 15 g, the frost generated in the freezer compartment 3 can be collected in the low temperature evaporator 20 and the stored food can be quickly defrosted by the defrosting heater 23 without raising the temperature. can.

As described above, according to the present invention, in a refrigeration cycle using a non-azeotropic mixed refrigerant, the compressor 6
A compressor 8 and a gas-liquid separator 9 are installed on the refrigerant pipe connected to the gas-liquid separator 9.
A heat exchanger 11 is connected to the gas-liquid separator 9.
The first heat exchanger 11 is connected to the liquid feed pipe 12 via a first throttle mechanism 13, a freezing evaporator 14, and a refrigeration evaporator 15, and a second heat exchanger is connected to the first heat exchanger 11. 18, second throttle mechanism 19 and low temperature evaporator 20
Since the defrosting heater 23 is installed near the low-temperature evaporator 20, the high-temperature evaporator 1
Not only can the frost that has formed in the refrigerator compartment 4 be moved to the low-temperature evaporator 20 by diffusion phenomenon to collect the frost and defrost it without raising the temperature, but it can also be defrosted in a short time without heating the entire peripheral wall of the freezer compartment. Therefore, it has excellent effects such as being able to increase refrigeration efficiency.

[Brief explanation of the drawing]

1 and 2 are diagrams for explaining a conventional freezer/refrigerator, FIG. 3 is a sectional view of the freezer/refrigerator according to the present invention, FIG. 4 is a line diagram of the present invention, and FIGS. Figure 6 is each graph for explaining the present invention. DESCRIPTION OF SYMBOLS 1... Main body, 2... Refrigeration compartment, 3... Freezer compartment, 6... Compressor, 8... Condenser, 9... Gas-liquid separator, 13... First throttling mechanism, 14... Refrigeration evaporator, 15... Refrigeration evaporator 18... second heat exchanger, 19... second throttle mechanism,
20...Low temperature evaporator, 23...Defrosting heater.

Claims (1)

[Claims] 1. In a refrigerator-freezer in a refrigeration cycle that uses a non-azeotropic mixed refrigeration medium, a condenser and a gas-liquid separator are connected in sequence to the discharge pipe of the compressor, and a first heat exchanger is connected to the pneumatic pipe of the gas-liquid separator. A first throttling mechanism, a freezing evaporator, a refrigeration evaporator, and a first heat exchanger are connected in this order to the liquid feed pipe of the gas-liquid separator, and the pneumatic feed pipe is A compressor is connected to a reflux pipe of the first heat exchanger that communicates with the pneumatic pipe through the first heat exchanger, and a compressor is connected to the reflux pipe of the first heat exchanger that communicates with the pneumatic pipe through the first heat exchanger. A second heat exchanger is connected to a connecting pipe of the first heat exchanger that communicates with the liquid feed pipe via the heat exchanger, and a second heat exchanger that communicates with the connecting pipe via the second heat exchanger. A second throttle mechanism, a low-temperature evaporator equipped with a defrosting heater, and a second heat exchanger are sequentially connected to the connecting pipe, and the second heat exchanger allows the refrigerant passing through the connecting pipe and the refrigerant passing through the connecting pipe to be connected in sequence. The return pipe of the second heat exchanger, which communicates with the connecting pipe through the second heat exchanger, is connected to the reflux pipe, and the low-temperature evaporator is connected to the freezing chamber formed in the main body. Freezer/refrigerator characterized by being installed in.