JPH1019418A - Freezer refrigerator - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the energy consumption efficiency and to reduce the size and the size of the expansion device. Further, the cooling performance at the time of startup and the cooling efficiency at the time of operation are improved. SOLUTION: The refrigerant discharged from a compressor 1 constitutes a refrigeration cycle which returns to a compressor through a condenser 5, a throttle device 9, and an evaporator 11, and the refrigerant includes a hydrocarbon-based refrigerant or an HFC-based refrigerant. Use refrigerant. A double-pipe heat exchanger 23 is provided, in which heat exchange is performed by the high-pressure refrigerant discharged from the condenser 5 and the low-pressure refrigerant discharged from the evaporator 11 flowing inside and outside. Are provided with a pressure reducing function having a large throttle action and a refrigerant flow reducing function having a small throttle action.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator which uses a refrigerant other than the HCFC system, which is considered to adversely affect the global environment.

[0002]

2. Description of the Related Art Generally, a refrigerator comprises a refrigeration cycle in which refrigerant discharged from a compressor passes through a condenser, a throttle device, and an evaporator and returns to the compressor again. The refrigerant flowing through the refrigeration cycle exchanges heat with the air passing through the evaporator in the evaporator, and the cooled air is sent into the refrigerator.

[0003]

SUMMARY OF THE INVENTION In a refrigerator-freezer,
At present, high efficiency is required along with energy saving. For example,
In order to improve the energy consumption efficiency, a heat exchange section is formed to increase the amount of heat exchange between the condenser outlet refrigerant and the evaporator outlet refrigerant sent to the compressor. The heat exchange section is connected to the outlet side of the condenser, and has a structure in which a capillary tube serving as a throttle device and a suction pipe connected to the outlet side of the evaporator are soldered together.
Thereby, heat exchange is performed between the high-pressure refrigerant at the condenser outlet and the low-pressure refrigerant at the evaporator outlet via the pipe, so that energy consumption efficiency according to the amount of heat exchange can be expected. Become like

In this case, as shown in FIG.
Although the amount of heat exchange is recognized in the HCFC-based refrigerants such as the above, for example, the compressor suction temperature is almost horizontal from -30 ° C to 60 ° C, and it is not possible to expect a great improvement in energy consumption efficiency. It is.

[0005] Further, since the ratio of the liquid refrigerant in the depressurization process is high, if a normal capillary tube is used as the expansion device, the capillary tube becomes extremely long, resulting in an increase in size. On the other hand, when a thin capillary tube having a strong squeezing action is used, there has been a problem that clogging and rising of the tube are deteriorated.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a refrigerator-freezer which does not cause an increase in size or clogging, and which improves the cooling performance and cooling efficiency.

[0007]

In order to achieve the above object, the present invention provides a refrigeration cycle in which refrigerant discharged from a compressor passes through a condenser, a throttle device, and an evaporator, and returns to the compressor again. In a refrigerating refrigerator, a hydrocarbon-based refrigerant or an HFC-based refrigerant is used as the refrigerant, and the high-pressure refrigerant discharged from the condenser and the low-pressure refrigerant discharged from the evaporator flow inside and outside to exchange heat. While the double-pipe heat exchanger is performed, the expansion device has a structure having a large pressure reduction function and a small refrigerant flow reduction function.

In a preferred embodiment, the expansion device has a structure in which an expansion valve is arranged on the upstream side and a capillary tube is arranged in series on the downstream side.

Alternatively, a structure in which a thin capillary tube is arranged on the upstream side and a thick capillary tube is arranged in series on the downstream side.

Further, the double-pipe heat exchanger has a double structure of an inner pipe pipe and an outer pipe pipe, and the pipe diameter of one of the pipe pipes through which the low-pressure refrigerant flows in the double-pipe heat exchanger area. By increasing the thickness, the pressure loss caused by heating the refrigerant to increase the specific volume is reduced.

Alternatively, a liquid refrigerant is formed by forming a double structure of an inner pipe pipe and an outer pipe pipe, and reducing the pipe diameter of one of the pipe pipes through which the high-pressure refrigerant flows in the double pipe heat exchanger region. In this state, the pressure is reduced to increase the flow velocity without changing the temperature level of the refrigerant.

Alternatively, by adopting a double structure of an inner pipe pipe through which a high-pressure refrigerant flows and an outer pipe pipe through which a low-pressure refrigerant flows, it is possible to reduce the amount of refrigerant charged in the refrigerant and enhance safety.

[0013] Alternatively, by adopting a double structure of an inner pipe pipe through which a low-pressure refrigerant flows and an outer pipe through which a high-pressure refrigerant flows,
Reduces heat penetration into the refrigeration cycle.

Alternatively, a processing surface and a processing member for promoting heat transfer are provided inside and outside the inner pipe tube of the double tube heat exchanger.

According to such a refrigerator, the refrigerant discharged from the compressor constitutes a refrigeration cycle which returns to the compressor after passing through the condenser, the throttle device, and the evaporator. In this case, since a hydrocarbon-based refrigerant or an HFC-based refrigerant is used as the refrigerant, a large heat exchange amount is obtained in the double-tube heat exchanger, so that the energy consumption efficiency is greatly improved as compared with the conventional HCFC-based refrigerant. .

A portion occupying the liquid phase in the depressurization process, the upstream side is a thin capillary tube or an expansion valve having a large decompression effect, and the downstream side after entering the gas-liquid two-phase region is a thick capillary tube or a decompression portion. Due to the expansion valve having a small effect, the flow rate of the refrigerant at the time of rising is large, and the refrigerant flow is narrowed and small at the time of stable operation. In addition, the cooling performance at the time of startup and the cooling efficiency at the time of steady operation can be improved.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be specifically described below with reference to FIGS.

In FIG. 1, reference numeral 1 denotes a compressor of the refrigerator-freezer 3, and a refrigerant discharged from the compressor 1 is supplied to a condenser 5 having a dew-proof pipe 5a, a dryer 7, a throttle device 9,
A refrigeration cycle that returns to the compressor 1 through the evaporator 11 is configured.

The refrigerant may be a hydrocarbon-based refrigerant such as R290, R600a or H-type refrigerant such as R410A, R134a.
Use FC-based refrigerant.

The compressor 1 functions to discharge the refrigerant sent into the inlet 1a as a high-temperature and high-pressure gas from the outlet 1b.

The condenser 5 functions to convert the high-temperature and high-pressure gas from the compressor 1 from a gaseous state to a liquid refrigerant by performing heat exchange with air by a condensing fan 13.

The dryer 7 functions to remove water, separate into gas and liquid, and temporarily store them.

The expansion device 9 has a structure in which an expansion valve 15 having a large pressure reducing effect capable of being throttled to the minimum at the upstream side and a thick capillary tube 17 having a small diameter at the downstream side having a small pressure reducing effect are arranged in series. In this case, a thin capillary tube 18 may be used instead of the upstream expansion valve 15 as shown in FIG. Alternatively, as shown in FIG. 8, the expansion device 9 may be an electric expansion valve 18 that can control a small throttle amount to a large throttle amount.

The evaporator 11 exchanges heat with the refrigerant by the air from the evaporating fan 19, and the refrigerant has a low pressure.
The gas becomes a low-temperature gas, and the air is cooled and sent into the storage. The gaseous refrigerant sent out from the evaporator 11 is stored in the accumulator 21 with the liquid refrigerant flowing therewith, and only the gaseous refrigerant is taken out. In the double tube heat exchanger 23, heat exchange is performed. Muffler 2
The compressor 7 is fed into the suction port 1a of the compressor 1 through the same.

The double pipe heat exchanger 23 has an inner pipe pipe 29
And one end of the inner pipe 29 is connected to the outlet side of the condenser 5 via the dryer 7, and the other end is connected to the expansion valve 15. One end of the outer pipe tube 31 is connected to the evaporator 1 via the accumulator 21.
The other end of the compressor 1 is connected to the suction port 1a of the compressor 1 via a check valve 25 and a muffler 27.

According to the refrigerating refrigerator configured as described above, the refrigerant discharged from the compressor 1 forms a refrigeration cycle that returns to the compressor 1 through the condenser 5, the expansion device 9, and the evaporator 11 again. . In this case, since the hydrocarbon-based refrigerant or the HFC-based refrigerant is used as the refrigerant, the double-tube heat exchanger 23 has a right shoulder with respect to the compressor suction temperature that changes according to the heat exchange amount as shown in FIG. It can be seen that energy consumption efficiency indicating a rising slope can be obtained.

Thus, the energy consumption efficiency can be improved.

In this case, as shown in FIGS. 3 and 4, a processing surface provided with a processing groove 33 or a fin 35 for promoting heat transfer is provided on the outer periphery of the inner pipe tube 29, or as shown in FIGS. 5 and 6. By providing the processing groove 33 or the twisted heat transfer tape 37 serving as a heat transfer member on the inner surface of the inner pipe pipe 29, it is possible to further improve the heat transfer coefficient. Alternatively, in the double-pipe heat exchanger 23, the high-pressure refrigerant flows through the inner pipe pipe 29 and the low-pressure refrigerant flows through the outer pipe pipe 31, thereby reducing the amount of refrigerant in the refrigerant and improving safety. Enhanced. Alternatively, the intrusion of heat into the refrigeration cycle can be reduced by allowing the low-pressure refrigerant to flow through the inner pipe pipe 29 and the high-pressure refrigerant to flow through the outer pipe pipe 31, respectively.

In the expansion device 9, the upstream side of the gas-liquid two-phase, which is the portion occupied by the liquid refrigerant, is the expansion valve 1.
5, the pressure reduction effect is large, or the refrigerant flow reduction effect is small on the downstream side due to the thin capillary tube 17, so that the refrigerant flow rate at the start-up is large, and the refrigerant flow is narrowed and small at the time of stability, resulting in clogging. Will not be done. In addition, the cooling performance at the time of startup and the cooling efficiency at the time of steady operation can be improved.

On the other hand, in the condensing area α1, as in the refrigeration cycle shown in FIG. 9, the throttle device 9 is set so that the high-pressure side refrigerant inlet is almost saturated liquid, and in the evaporator area α2, the low-pressure side refrigerant inlet is almost saturated vapor. By setting, the refrigerant in the condenser 5 and the evaporator 11 can be kept in the two-phase region and the heat transfer coefficient on the refrigerant side can be improved, so that the energy consumption efficiency of the refrigeration cycle can be improved.

FIG. 10 shows another embodiment of the double tube heat exchanger 23. That is, the pipe diameter a of the outer pipe pipe 31 which is the outlet side of the evaporator 11 of the double pipe heat exchanger 23
And b are made thicker in the middle such that a> b.

The other components are the same as those shown in FIG. 1 and the same reference numerals are used, and detailed description is omitted.

Therefore, according to this embodiment, in addition to the above-described effects, since the pipe diameter of the outer pipe 31 on the outlet side of the evaporator 11 is increased from the middle, the specific volume is increased by heating the refrigerant vapor. Therefore, it is possible to reduce the pressure loss caused by increasing the flow velocity.

FIG. 11 shows another embodiment of the double tube heat exchanger 23. That is, the pipe diameters c and d of the inner pipe pipe 29 on the outlet side of the condenser 5 are reduced from the middle to c <d.
It has a shape that changes.

The other components are the same as those shown in FIG.

According to this embodiment, by reducing the inner pipe pipe 29 on the outlet side of the condenser 5 from the middle, the pressure drops in the state of the liquid refrigerant, and the flow velocity can be increased without changing the temperature level. Thereby, the heat transfer coefficient of the liquid refrigerant is improved, and the amount of heat transfer can be increased.

[0037]

As described above, according to the refrigerator-freezer of the present invention, the following effects can be obtained.

(1) The energy consumption efficiency of the refrigeration cycle can be improved.

(2) Liquid return to the compressor can be prevented, and efficient compression operation can be performed. (3) The size of the aperture device can be reduced.

(4) The cooling performance at the time of startup and the cooling efficiency at the time of operation can be improved.

(5) The compression loss of the gas refrigerant in the double tube heat exchanger can be reduced and the heat transfer coefficient can be improved.

(6) The heat transfer coefficient of the liquid refrigerant in the double tube heat exchanger can be improved.

[Brief description of the drawings]

FIG. 1 is an overall explanatory diagram showing a circuit diagram of a refrigerator-freezer according to the present invention.

FIG. 2 is an explanatory diagram of energy consumption efficiency with respect to a heat exchange amount of each refrigerant.

FIG. 3 is an explanatory view of a part in which a processing groove is provided on the outer periphery of an inner pipe tube.

FIG. 4 is an explanatory view of a part in which fins are provided on the outer periphery of an inner pipe tube.

FIG. 5 is an explanatory view of a part in which a processing groove is provided on the inner periphery of the inner pipe tube.

FIG. 6 is an explanatory view of a part in which a twisted heat transfer tape is provided inside the inner pipe tube.

FIG. 7 is an explanatory view similar to FIG. 1, showing another embodiment of the diaphragm device.

FIG. 8 is an explanatory view similar to FIG. 1, showing another embodiment of the aperture device.

FIG. 9 is an explanatory view showing a refrigeration cycle of a refrigerant.

FIG. 10 is an overall circuit explanatory diagram of a refrigerator-freezer showing another embodiment of the double-tube heat exchanger.

FIG. 11 shows another embodiment of the double tube heat exchanger.
Circuit explanatory diagram similar to FIG.

FIG. 12 is an explanatory diagram showing the energy consumption efficiency of the conventional refrigerant with respect to the amount of heat exchange.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 5 Condenser 9 Throttling device 11 Evaporator 23 Double tube heat exchanger

Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location F28D 7/10 F28D 7/10 A (72) Inventor Kazutoshi Myojin 3-3-9 Shimbashi, Minato-ku, Tokyo Toshiba Abu E Co., Ltd.

Claims (8)

[Claims] The refrigerant discharged from the compressor is supplied to a condenser,
In a refrigerating refrigerator constituting a refrigerating cycle passing through a throttle device and an evaporator and returning to a compressor again, a hydrocarbon-based refrigerant or an HFC-based refrigerant is used as the refrigerant, and a high-pressure refrigerant discharged from a condenser and an evaporator. A double-pipe heat exchanger in which heat exchange is performed by the low-pressure refrigerant discharged from the inside and the outside flowing therethrough, while the expansion device is provided with a large pressure reduction function and a small refrigerant flow reduction function. A refrigerator-freezer characterized by the following. 2. The refrigerator according to claim 1, wherein the expansion device has a structure in which an expansion valve is arranged in series on an upstream side and a capillary tube is arranged in series on a downstream side. 3. The refrigerator according to claim 3, wherein the expansion device has a structure in which a thin capillary tube is arranged in series on the upstream side and a thick capillary tube is arranged in series on the downstream side. 4. The double-pipe heat exchanger has a double structure of an inner pipe pipe and an outer pipe pipe, and in the area of the double-pipe heat exchanger, the pipe diameter of one of the pipe pipes through which the low-pressure refrigerant flows is halfway. 2. The refrigerator according to claim 1, wherein the thickness of the refrigerator is increased. 5. The double-pipe heat exchanger has a double structure of an inner pipe pipe and an outer pipe pipe, and in the double-pipe heat exchanger region, the pipe diameter of one of the pipe pipes through which the high-pressure refrigerant flows is halfway. 2. The refrigerator according to claim 1, wherein the thickness of the refrigerator is reduced. 6. The refrigerator according to claim 1, wherein the double-pipe heat exchanger has a double structure of an inner pipe pipe through which high-pressure refrigerant flows and an outer pipe pipe through which low-pressure refrigerant flows. 7. The refrigerator according to claim 1, wherein the double-pipe heat exchanger has a double structure of an inner pipe through which a low-pressure refrigerant flows and an outer pipe through which a high-pressure refrigerant flows. 8. A processing surface or a processing member for promoting heat transfer is provided inside and outside the inner pipe tube of the double tube heat exchanger. A refrigerator as described.