JPH0875276A - Freezer device with hfc system non-azeotropic refrigerant mixture - Google Patents

Abstract

PURPOSE: To provide a freezer device which has no possibility to damage an ozone layer and a composition of refrigerant mixture is less deteriorated during a freezing cycle by a method wherein there is provided a bypass pipe passage having a check valve with its one end being connected to a part near an inlet of a heat exchanging coil of a condensor and/or an evaporator and the other end being connected to a part near its outlet. CONSTITUTION: This device comprises a bypassing pipe passage 10 with its one end being connected to a part near an inlet port of a heat exchanging coil 7 of a condensor of a freezing device having HFC system non-azeotropic refrigerant mixture and the other end being connected to a part near an outlet port of the coil. This bypassing pipe passage 10 is provided with a check valve 11. That is, refrigerant mixture gas entered from an inlet 8 into the heat exchanging coil 7 flows through the coil, is heat exchanged there to become liquid refrigerant mixture and then the mixture flow out of an outlet 9. Refrigerant mixture of main gaseous phase is bypassed through the bypassing pipe passage, thereby it is possible to mix gaseous phase and liquid phase of the refrigerant mixture to each other. In addition, since the check valve 11 is arranged, the refrigerant mixture of liquid phase does not flow back through the bypassing pipe passage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus using an HFC-based non-azeotropic refrigerant mixture, and more specifically to a non-flammable HFC which does not have a risk of depleting the ozone layer.
The present invention relates to a refrigerating apparatus which can be stably operated for a long period of time because the composition change of the refrigerant mixture in the refrigeration cycle can be reduced even when a non-azeotropic refrigerant mixture is used.

[0002]

2. Description of the Related Art Conventionally, a refrigerant used in a refrigerator is composed of dichlorodifluoromethane (hereinafter referred to as R-12) or an azeotropic mixed refrigerant R-12 and 1,1-difluoroethane (R-152a). There are many R-500s. R
The boiling point of −12 is −29.65 ° C. at atmospheric pressure, and the boiling point of R500 is −33.45 ° C., which is suitable for a normal refrigeration system and is a mineral compatible with a CFC-based refrigerant such as R-12. Refrigeration cycles that use refrigerating machine oils such as oils and alkylbenzene-based oils have reached high quality levels such as reliability and durability.

However, due to their high ozone depletion potential, each of the above refrigerants destroys the ozone layer when it reaches the ozone layer above the earth by being released into the atmosphere.
The destruction of the ozone layer is caused by chlorine groups (Cl) in the refrigerant. Therefore, a refrigerant having a low chlorine group content, for example, chlorodifluoromethane (HCFC-22,
R-22), chlorine-free refrigerants such as difluoromethane (HFC-32, hereinafter R-32), pentafluoroethane (HFC-125, hereinafter R)
-125) or 1,1,1,2-tetrafluoroethane (HFC-134a, hereinafter R-134a),
Alternatively, mixtures of these are considered as alternative refrigerants for these. The boiling point of R-22 is -40.
At 82 ° C., the boiling point of R-32 is −51.7 ° C. and R-1.
The boiling point of 25 is -48.5 ° C, and the boiling point of R-134a is
It is -26.5 degreeC.

The HFC-based refrigerant mixture is a mixture of HFC-based refrigerants.
It is a mixture of three or more kinds, and usually, there are many combinations in which the boiling point and the dew point of the mixture are different. In the present invention, these mixtures are referred to as HFC-based non-azeotropic refrigerant mixture. The HFC-based non-azeotropic refrigerant mixture is specifically, for example,
R125 / R143a / 134a (weight ratio 44/52 /
4) (R404A, boiling point -46.78 ° C, dew point -46.
08 ° C, trade name: HP62, manufactured by DuPont, hereinafter HP6
2), R32 / R125 / 134a (weight ratio 20)
/ 40/40) (R407A, boiling point −45.4 ° C., dew point −38.8 ° C., trade name: KLEA60G2, manufactured by ICI, hereinafter referred to as KLEA60).

FIG. 2 shows an example of a typical refrigeration circuit. 1 is a compressor, 2 is a condenser, 3 is a dryer, 4 is a capillary tube, 5 is an evaporator, and 6 is an accumulator.
The arrow indicates the flow direction of the refrigerant. Since the refrigeration cycle using the HFC-based non-azeotropic refrigerant mixture is a non-azeotropic mixture, the composition of the refrigerant mixture changes in each part of the refrigeration cycle, and for example, the inlet of the heat exchange coil of the condenser 2 changes depending on the day of operation. Between the outlet and the outlet, or between the inlet and the outlet of the heat exchange coil of the evaporator 5, the composition of the refrigerant mixture is large, and the temperature change is large, and the refrigerating capacity and the refrigerating capacity are not uniform, so that it is stable for a long time. There is a drawback that you can not drive.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to use an HFC-based non-azeotropic refrigerant mixture which is non-flammable and has no risk of depleting the ozone layer, and the inlet and outlet of the heat exchange coil of the condenser. It is to provide a refrigerating apparatus which can be operated stably over a long period of time by making the composition of the refrigerant mixture uniform between the two or between the inlet and outlet of the heat exchange coil of the evaporator and reducing the temperature change. .

[0007]

Means for Solving the Problems As a result of intensive studies in view of the above-mentioned problems, the present inventor has provided a bypass conduit connecting the inlet and outlet vicinity of a heat exchange coil, and a refrigerant mixture is passed through the bypass conduit. The inventors have found that the above problems can be solved by bypassing and mixing the gas phase and the liquid phase of the refrigerant mixture, and have completed the present invention.

According to the first aspect of the present invention, a condenser for condensing and liquefying a refrigerant, a dryer for removing water in a refrigeration circuit, a capillary tube, an evaporator for evaporating a liquefied refrigerant, an accumulator, and an evaporated vaporized refrigerant. In a refrigerating apparatus including a compressor for compressing and discharging the refrigerant to a condenser, and using a HFC-based non-azeotropic refrigerant mixture as a refrigerant compressed by the compressor, a heat exchange coil of the condenser and / or the evaporation HFC system having a bypass pipe, one end of which is connected to the vicinity of the inlet of the heat exchange coil of the reactor and the other end of which is connected to the vicinity of the outlet, and a check valve provided on the bypass pipe. It is a refrigeration system using a non-azeotropic refrigerant mixture.

According to the second aspect of the present invention, the refrigerant mixture in the coil near the inlet is mainly in the gas phase, and the refrigerant mixture in the coil near the outlet is mainly in the liquid phase. The refrigeration apparatus according to claim 1, wherein the refrigerant mixture is bypassed through the bypass pipe line to mix the gas phase and the liquid phase of the refrigerant mixture.

According to a third aspect of the present invention, the refrigerant mixture in the coil near the inlet is mainly in the liquid phase, and the refrigerant mixture in the coil near the outlet is mainly in the gas phase. The refrigerating apparatus according to claim 1, wherein the refrigerant mixture is bypassed through the bypass pipe line to mix the liquid phase and the gas phase of the refrigerant mixture.

The invention according to claim 4 of the present invention is characterized in that the bypass line is provided so as to minimize the composition change of the refrigerant mixture at the inlet and the outlet of the heat exchange coil. The refrigeration apparatus according to claim 3.

According to a fifth aspect of the present invention, the bypass line is provided so that the temperature difference between the inlet and the outlet of the heat exchange coil is minimized.
It is the described refrigeration apparatus.

According to a sixth aspect of the present invention, the refrigerating machine oil is a mineral oil type lubricating oil, an alkylbenzene type lubricating oil, an ester type lubricating oil, an ether type lubricating oil or a mixture thereof. It is a refrigerator.

[0014]

[Function] A bypass pipe line provided with a check valve is provided to connect the vicinity of the inlet and the vicinity of the outlet of the heat exchange coil of the condenser and the heat exchange coil of the evaporator, and the refrigerant mixture is allowed to flow through the bypass pipe. By mixing the vapor phase and the liquid phase of the refrigerant mixture with each other, the composition change of the refrigerant mixture at the inlet and the outlet of the heat exchange coil can be minimized and the temperature change can be minimized. In the present invention, the vicinity of the inlet of the heat exchange coil refers to the portion from the central portion of the entire length from the inlet of the refrigerant of the heat exchange coil to the outlet of the refrigerant, and the outlet vicinity of the heat exchange coil, The part from the central portion of the entire length of the heat exchange coil from the refrigerant inlet to the refrigerant outlet to the outlet is referred to.

In the present invention, there is no particular limitation as to where the bypass pipe connecting the inlet vicinity and the outlet vicinity of the heat exchange coil is installed near the inlet or the outlet.
The temperature, pressure, and refrigerant composition of the heat exchange coil can be appropriately determined so as to minimize the composition change of the refrigerant mixture between the inlet and the outlet of the heat exchange coil and minimize the temperature change. It is preferable that the portion of the refrigerant mixture flowing through the heat exchange coil, which is mainly in the gas phase, and the portion that is mainly in the liquid phase are connected by a bypass line to mix them.

In the present invention, the amount of the refrigerant mixture to be bypassed through the bypass line is also not particularly limited. The amount of the refrigerant mixture to be bypassed can be appropriately determined so as to minimize the composition change of the refrigerant mixture between the inlet and the outlet of the heat exchange coil and minimize the temperature change. In the present invention,
The refrigerating machine oil is not particularly limited. Mineral oil-based lubricating oil, alkylbenzene-based lubricating oil, ester-based lubricating oil, ether-based lubricating oil, or a mixture thereof can be preferably used.

[0017]

EXAMPLES The contents of the present invention will be described more specifically below with reference to examples, but the present invention is not limited to these contents. In FIG. 1, a bypass line 10 is provided, one end of which is connected to the inlet vicinity of the heat exchange coil 7 of the condenser of the refrigeration system using the HFC-based non-azeotropic refrigerant mixture, and the other end of which is connected to the outlet vicinity. And the check valve 1 in the bypass line 10.
1 shows a heat exchange coil 7 provided with 1. The arrow indicates the flow direction of the mixed refrigerant. The refrigerant mixture gas that has entered the heat exchange coil 7 from the inlet 8 flows through the coil and undergoes heat exchange to become a liquid refrigerant mixture and exits from the outlet 9. The refrigerant mixture is mainly in the gas phase near the inlet of the heat exchange coil 7, and the refrigerant mixture is mainly in the liquid phase near the outlet of the heat exchange coil 7, and is mainly in the gas phase through the bypass pipe line. Bypassing the mixture allows the vapor phase and the liquid phase of the refrigerant mixture to be mixed. Since the check valve 11 is provided, the refrigerant mixture in the liquid phase does not flow backward through the bypass line. By mixing the gas phase and the liquid phase of the refrigerant mixture, the composition change of the refrigerant mixture at the inlet 8 and the outlet 9 of the heat exchange coil 7 can be minimized and the temperature change can be minimized.

[0018]

INDUSTRIAL APPLICABILITY The refrigerating apparatus using the HFC-based non-azeotropic refrigerant mixture according to the present invention has no risk of depleting the ozone layer, and the non-flammable HFC-based non-azeotropic refrigerant mixture is used in the refrigeration cycle. Since the change in composition of the refrigerant mixture can be reduced, stable operation can be achieved for a long period of time. Since the composition change of the refrigerant mixture at the inlet and the outlet of the heat exchange coil of the condenser or the heat exchange coil of the evaporator can be minimized and the temperature change can be minimized, the design and performance of the heat exchange coil can be easily set.
Even if the refrigerant mixture leaks to the outside of the system during the refrigeration cycle operation, the composition of the refrigerant mixture is uniform regardless of the leak location, so that maintenance management is easy. The refrigerating apparatus of the present invention is economical because it has a simple structure, and has a large effect as described above and a high industrial utility value.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a heat exchange coil provided with a bypass line.

FIG. 2 is an example of a refrigeration circuit of a typical refrigeration system.

[Explanation of symbols]

 1 Compressor 2 Condenser 3 Dryer 4 Capillary tube 5 Evaporator 6 Accumulator 7 Heat exchange coil 8 Inlet 9 Outlet 10 Bypass line 12 Check valve

Claims (6)

[Claims] 1. A condenser for condensing and liquefying a refrigerant, a dryer for removing water in a refrigeration circuit, a capillary tube, an evaporator for evaporating a liquefied refrigerant, an accumulator, and a refrigerant which has been evaporated and vaporized is discharged to a condenser. In a refrigerating apparatus including a compressor, etc., using an HFC-based non-azeotropic refrigerant mixture as a refrigerant compressed by the compressor, in the vicinity of an inlet of the heat exchange coil of the condenser and / or the heat exchange coil of the evaporator. An HFC-based non-azeotropic refrigerant mixture is used, characterized in that a bypass pipe having one end connected to the section and the other end connected to the vicinity of the outlet is provided, and a check valve is provided at the bypass pipe. Refrigeration equipment. 2. The refrigerant mixture in the coil near the inlet is predominantly in the vapor phase, the refrigerant mixture in the coil near the outlet is predominantly in the liquid phase, and the refrigerant is passed through the bypass line. The refrigeration system of claim 1, wherein the gas phase and the liquid phase of the refrigerant mixture are mixed by bypassing the mixture. 3. The refrigerant mixture in the coil near the inlet is mainly in a liquid phase, the refrigerant mixture in the coil near the outlet is mainly in a gas phase, and the refrigerant is passed through the bypass line. The refrigeration system according to claim 1, wherein the liquid phase and the gas phase of the refrigerant mixture are mixed by bypassing the mixture. 4. The refrigerating apparatus according to claim 1, wherein the bypass pipe line is provided so that a change in the composition of the refrigerant mixture at the inlet and the outlet of the heat exchange coil is minimized. 5. The refrigerating apparatus according to claim 1, wherein the bypass pipe line is provided so that a temperature difference between an inlet and an outlet of the heat exchange coil is minimized. 6. The refrigerating apparatus according to claim 1, wherein the refrigerating machine oil is a mineral oil type lubricating oil, an alkylbenzene type lubricating oil, an ester type lubricating oil, an ether type lubricating oil or a mixture thereof.