US20070180853A1

US20070180853A1 - Refrigerator

Info

Publication number: US20070180853A1
Application number: US11/618,982
Authority: US
Inventors: Hyoung Lim; Sung Jhee; Nam Cho
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2006-01-03
Filing date: 2007-01-02
Publication date: 2007-08-09
Also published as: EP1804011A3; CN1995877A; EP1804011A2; KR20070089260A; KR100785116B1

Abstract

There is provided a refrigerator. The refrigerator includes a compressor for compressing a refrigerant, a condenser for heat-exchanging the compressed refrigerant with ambient air, an expansion member for expanding the heat-exchanged refrigerant, a condensing pipe interconnecting the condenser and the expansion member, a vaporizer for heat-exchanging the expanded refrigerant with a cooling air in a freezing or cooling chamber, and a suction pipe interconnecting the vaporizer and the compressor and associated with the condensing pipe to allow a heat exchange between the suction pipe and the condensing pipe.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a refrigerator, and more particularly, to a refrigerator having an improved cooling cycle that can reduce the power consumption and improve a coefficient of performance (COP) by efficiently using thermal energy wasted during a refrigerant is introduced into an expansion valve through a condenser.
2. Description of the Related Art
A refrigerator is an electrical appliance for cooling or freezing food to preserve the food.
Generally, the refrigerator can be classified into a top mount refrigerator in which a freezing chamber and a chilling chamber are partitioned up and down, a bottom freezer refrigerator in which a freezing chamber and a cooling chamber are partitioned down and up, a side-by-side refrigerator in which a freezing chamber and a cooling chamber are partitioned left and right.
Especially, the side-by-side refrigerator has a freezing and cooling chamber doors that are opened toward both sides. The side-by-side has a relatively volume compared with other types and a variety of functions. Therefore, the side-by-side refrigerators have been widely used in recent years.
Many of the prior art refrigerators are an exposure type where a condenser is exposed to an external side. That is, A refrigerant flowing along a pipe connecting the condenser to a capillary maintains a temperature of about 40-45° C. while a refrigerant flowing along a suction pipe connecting a vaporizer to a compressor maintains a temperature of about −25-−30° C. In addition, in the prior art refrigerator, in order to improve the COP, a portion of the suction pipe is designed to contact the capillary. That is, when the heat is transferred from the capillary to the suction pipe, a temperature of the suction pipe increases to pre-heat the refrigerant directing toward the compressor, thereby reducing the compressing work. The reduction of the compressing work increases the COP and reduces the electric power consumption.
However, in the cooling cycle, the heat generated from the refrigerant flowing from the condenser toward the capillary is wasted to the ambient air. That is, the heat discharged during the refrigerant passed through the condenser flows toward the capillary cannot be efficiently used, thereby generating a cyclic minor loss.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a refrigerator that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a refrigerator having an improved cooling cycle that can reduce the power consumption and improve a coefficient of performance (COP) by efficiently using thermal energy wasted during a refrigerant is introduced into an expansion valve through a condenser.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a refrigerator including: a compressor for compressing a refrigerant; a condenser for heat-exchanging the compressed refrigerant with ambient air; an expansion member for expanding the heat-exchanged refrigerant; a condensing pipe interconnecting the condenser and the expansion member; a vaporizer for heat-exchanging the expanded refrigerant with a cool air in a freezing or cooling chamber; and a suction pipe interconnecting the vaporizer and the compressor and associated with the condensing pipe to allow a heat exchange between the suction pipe and the condensing pipe.
In another aspect of the present invention, there is provided a refrigerator including: a compressor for compressing a refrigerant; a condenser for condensing the compressed refrigerant with ambient air; an expanding valve for expanding the condensed refrigerant; and a vaporizer for heat-exchanging the expanded refrigerant with cool air of a freezing or cooling chamber, wherein a portion of a suction pipe corrected to an inlet of the compressor contacts a portion of a condensing pipe connected to an outlet of the condenser to allow for a heat exchange between the suction pipe and the condensing pipe.
In still another aspect of the present invention, there is provided a refrigerator comprising: a suction pipe interconnecting a vaporizer and a compressor; an expansion member heat-exchanging with a refrigerant flowing along the suction pipe; and a condensing pipe heat-exchanging with the refrigerant flowing along the suction pipe at an inlet of the expansion member.
In still yet another aspect of the present invention, there is provided a refrigerator comprising: pipes connected to each other such that a refrigerant flowing toward an inlet of a compressor after passing through a vaporizer can be heat-exchanged but not mixed with a refrigerant passing through an expansion member and/or a refrigerant passed through a condenser.
According to the present invention, the waste heat discharged from the refrigerant passed through the condenser is efficiently used during the compression process, thereby reducing the compressing work and increasing the COP.
Furthermore, since the compressing work is reduced, the electric power consumption for driving the compressor can be reduced.
In addition, since the pipe interconnecting the condenser and the capillary and the suction pipe is bonded in a helix shape, the heat exchange area increases to improve the space efficiency of the machine room, thereby reducing the overall volume of the refrigerator.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment (s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
FIG. 1 is a schematic view of a cooling system of a refrigerator according to an embodiment of the present invention;
FIG. 2 is a perspective view of a second heat-exchanging portion formed on a portion of a suction pipe contacting a condensing pipe in a cooling cycle according to an embodiment of the present invention; and
FIG. 3 is a P-H diagram illustrating a phase variation of a refrigerant during the cooling system of the present invention is operated.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.
FIG. 1 is a schematic view of a cooling system of a refrigerator according to an embodiment of the present invention.
Referring to FIG. 1, a refrigerator 10 having a cooling system according to an embodiment of the present invention includes a condensing pipe along which a refrigerant passed through a condenser flows and a suction pipe along which a refrigerant introduced into the compressor flows. The condensing pipe and a suction pipe contact each other to perform the heat exchange.
The refrigerator 10 includes a compressor 11 for compressing the refrigerant, a condenser 12 into which the refrigerant compressed with a high temperature and a high pressure by the compressor 11 is introduced, a capillary 14 for cooling the high temperature and high pressure refrigerant passed through the condenser 12 to a low temperature and a low pressure, a vaporizer 15 into which the refrigerant, which is converted into a two-phase state (a liquid phase and a vapor phase) while passing through the capillary 14, is introduced to heat-exchange with cool air of the freezing and cooling chambers, and a phase separator 16 for separating the refrigerant passed through the vaporizer 15 into vapor and liquid.
In addition, the refrigerator 10 further includes a dryer 13 interposed between the condenser 12 and the capillary 14, a condensing pipe 17 interconnecting the condenser 11 to the dryer 13, and a suction pipe 18 connecting the phase separator 16 to the compressor 11. In addition, the suction pipe 18 has a first heat-exchanging portion 191 contacting the capillary 14 for the heat-exchange and a second heat-exchanging portion 192 contacting the condensing pipe 17 for the heat-exchange.
With the above-described refrigerator, the suction pipe 18 receives heat from the capillary 14 and the condenser pipe 17 to increase the temperature of the refrigerant flowing toward the compressor 11. As the temperature of the refrigerant flowing toward the compressor 11 increases, the compressing work of the compressor is reduced. At this point, as the heat is transferred from the capillary 14 to the suction pipe 18, the temperature of the refrigerant is reduced at the inlet of the vaporizer 15. Therefore, an amount of the heat-exchange between the cool air in the refrigerator and the refrigerant in the vaporizer 15 increases. As a result, the time for reducing the cool air to a target temperature is reduced. In addition, the refrigerant flowing along the condensing pipe 17 releases its heat to the suction pipe 18, thereby increasing an amount of the refrigerant that is liquefied. Therefore, the change of success for introducing air into the capillary 14 is reduced as compared to the prior art refrigerator.
The refrigerant phase that varies by the above-described cooling cycle and the COP in the refrigerator of the present invention will now be described in more detail.
FIG. 2 is a perspective view of a second heat-exchanging portion formed on a portion of the suction pipe contacting the condensing pipe in the cooling cycle according to an embodiment of the present invention.
Referring to FIG. 2, the second heat exchange portion 192 is formed by a helix or spiral contact between the condensing pipe 17 and the suction pipe 18.
That is, since the condensing pipe 17 and the suction pipe 18 contact each other, the waste heat discharged from the condensing pipe 17 is transferred to the suction pipe 18. Here, likewise the contact between the capillary 14 and the suction pipe 18, the condensing pipe 17 may linearly contact the suction pipe. However, in order to reduce the electric power consumption, it is preferable that each length of the condensing and suction pipes 17 and 18 is about 80-100 cm. Therefore, when the condensing pipe 17 contacts the suction pipe linearly, it is difficult to take a space for the pipes 17 and 18 in a machine room. To solve this problem, the pipes 17 and 18 are coiled in the helix or spiral shape. In this case, the length of the pipes 17 and 18 is reduced to 10-12 cm that is almost identical to that of the dryer 13. Therefore, the space for receiving the second heat-exchanging portion 192 in the machine room can be sufficiently obtained. Here, the contacting portion between the condensing pipe 17 and the suction pipe 18 may be spirally coiled or bent or curved at a plurality of locations.
Instead of making the condensing and suction pipes 17 and 18 contact each other, the condensing pipe 17 may extends through the inside of the suction pipe 18. In this case, it is preferable that the refrigerant of the suction pipe 18 flows in a direction opposite to that where the refrigerant of the condensing pipe 17 flows to enhance the heat exchange efficiency.
That is, as the condensing pipe 17 extends through the inside of the suction pipe 18, the waste heat discharged through the condensing pipe 17 is fully transferred to the refrigerant flowing along the suction pipe 18, thereby increasing the thermal transfer rate up to 100% and thus dramatically reducing the electric power consumption as compared to the case where the suction and condensing pipe contact each other at their outer surfaces.
In addition, when the condensing and suction pipes 17 and 18 are coiled in the helix shape, the contacting area between the condensing and suction pipes 17 and 18 can increase to the maximum level in the limited machine room by properly adjusting a diameter of the helix.
FIG. 3 is a P-H diagram illustrating a phase variation of the refrigerant during the cooling system of the present invention is operated.
Referring to FIG. 3, in an ideal cooling cycle, the refrigerant going through compressing, condensing, expanding, and vaporizing processes goes through a-b-c-d.
Describing a refrigerant circulation in the cooling cycle, the refrigerant is compressed to a high temperature and high pressure by the compressor 11. The compressed refrigerant flows into the condenser 12 to be phase-changed into liquid by heat exchange with ambient air. The liquid refrigerant passed through the condenser 12 is directed to the capillary 14 via the dryer 13. Here, moisture contained in the refrigerant flowing into the capillary 14 is eliminated by the dryer.
Meanwhile, the refrigerant introduced into the capillary 14 is phase-changed into two-phase state (i.e., vapor and liquid states) with a low temperature and low pressure through a throttling process. Then, the two-phase refrigerant is introduced into the vaporizer 15 and heat-exchanged with the cool air of the freezing or cooling chambers. A part of the refrigerant is phase-changed from a liquid-phase into a vapor-phase by the heat transferred from the cool air in the freezing or cooling chambers. Then, the refrigerant passed through the vaporizer 15 passes through the phase-separator, in the course of which the liquid is filtered. Therefore, only the liquid refrigerant is reintroduced into the compressor 11.
A heat exchange between the refrigerants is realized by the heat conduction at the first heat-exchanging portion 191 where the suction pipe 18 contacts the capillary 14. In addition, an additional heat exchange between the refrigerants is realized by the heat conduction at the second heat-exchanging portion 192 where the suction pipe 18 contacts the condensing pipe 17.
That is, in the ideal cooling cycle,
Compressing Work [(w_c)_ideal]=h_b−h_a,
Condensing Heat [(q_out)_ideal]=h_b−h_c,
Expanding Heat=0, and
Vaporizing Heat [(q_in)_ideal]=h_a−h_d.
In addition, in a real cooling cycle that is actually applied to a refrigerator, since the heat is transferred from the capillary 14 to the suction pipe 18 by allowing the capillary 14 to contact the suction pipe 18, the refrigerant goes through e-b-c-g.
That is, in the real cooling cycle,
Compressing Work [(w_c)_real]=h_b−h_e,
Condensing Heat [(q_out)_real]=h_b−h_c,
Expanding Heat=h_c−h_g, and
Vaporizing Heat [(q_in)_real]=h_a−h_g
Meanwhile, in the cooling cycle according to the present invention, since there is a heat exchange between the condensing pipe 17 and the suction pipe 18 that contact each other, the temperature of the refrigerant flowing toward the compressor 11 further increases while the temperature of the refrigerant flowing toward the vaporizer further decreases. Therefore, in the cooling cycle according to the present invention,
Compressing Work [(w_c)_present]=h_b−h_f,
Condensing Heat [(q_out)_present]=h_b−h_c,
Expanding Heat=h_s−h_k, and
Vaporizing Heat [(q_in)_present]=h_a−h_k.
That is, since there are heat exchanges between the capillary 14 and the suction pipe 18 and between the condensing pipe 17 and the suction pipe 18, the sum of the discharged expanding heat (h_s−h_k) and the condensing heat (hc0hs) is to be identical to a heat value absorbed by the suction pipe 18. Therefore, the compression work is reduced as compared to that of the prior art cooling cycle.
Furthermore, the compression work can be dramatically reduced depending on a contacting length of the condensing pipe 17 and the suction pipe 18 as compared to the prior art cooling cycle.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

1. A refrigerator comprising:

a compressor for compressing a refrigerant;

a condenser for heat-exchanging the compressed refrigerant with ambient air;

an expansion member for expanding the heat-exchanged refrigerant;

a condensing pipe interconnecting the condenser and the expansion member;

a vaporizer for heat-exchanging the expanded refrigerant with a cool air in a freezing or cooling chamber; and

a suction pipe interconnecting the vaporizer and the compressor and associated with the condensing pipe to allow a heat exchange between the suction pipe and the condensing pipe.

2. The refrigerator according to claim 1, wherein an outer circumference of the condensing pipe contacts an outer circumference of the suction pipe by a predetermined length.

3. The refrigerator according to claim 1, wherein the condensing pipe and the suction pipe are coiled in a helix shape.

4. The refrigerator according to claim 1, wherein the condensing pipe extends through an inside of the suction pipe.

5. The refrigerator according to claim 1, wherein a part of the suction pipe contacts the expansion member.

6. The refrigerator according to claim 1, wherein the refrigerant flows along the suction pipe in a direction opposite to that where the refrigerant flows along the condensing pipe.

7. A refrigerator comprising:

a compressor for compressing a refrigerant;

a condenser for condensing the compressed refrigerant with ambient air;

an expanding valve for expanding the condensed refrigerant; and

a vaporizer for heat-exchanging the expanded refrigerant with cool air of a freezing or cooling chamber,

wherein a portion of a suction pipe connected to an inlet of the compressor contacts a portion of a condensing pipe connected to an outlet of the condenser to allow for a heat exchange between the suction pipe and the condensing pipe.

8. The refrigerator according to claim 7, wherein the portion where the suction pipe contacts the condensing pipe is coiled with a predetermined curvature.

9. The refrigerator according to claim 7, wherein the contact portion between the suction pipe and the condensing pipe is bent or curved at a plurality of locations to increase a heat-exchange area between the suction pipe and the condensing pipe.

10. The refrigerator according to claim 7, wherein the suction pipe contacts the condensing pipe in a way that the refrigerants in the pipes mutually flow in an opposite direction.

11. The refrigerator according to claim 7, wherein the suction pipe contacts a part of an outer circumference of the expansion valve to allow for the heat exchange between refrigerants flowing the suction pipe and the expansion valve.

12. The refrigerator according to claim 7, wherein the suction pipe contacts the expansion valve to realize a primary heat exchange between the refrigerants flowing along the suction pipe and the expansion valve and the suction pipe further contacts the condensing pipe to realize the secondary heat exchange between the refrigerants flowing along the suction pipe and the condensing pipe.

13. A refrigerator comprising

a suction pipe interconnecting a vaporizer and a compressor;

an expansion member heat-exchanging with a refrigerant flowing along the suction pipe; and

a condensing pipe heat-exchanging with the refrigerant flowing along the suction pipe at an inlet of the expansion member.

14. The refrigerator according to claim 13, wherein the refrigerant flowing along the suction pipe after passing through the vaporizer primarily absorbs heat from the expansion member and secondarily absorbs heat from the refrigerant flowing along the condensing pipe.

15. The refrigerator according to claim 13, wherein the refrigerant flowing along the suction pipe is heat-exchanged but not mixed with a refrigerant flowing along the expansion member or the condensing pipe.

16. The refrigerator according to claim 13, where a part of an outer circumference of the expansion member contacts a part of an outer circumference of the suction pipe for a heat exchange therebetween.

17. The refrigerator according to claim 13, wherein the suction pipe and the condensing pipe partly contact each other at their outer circumferences or the suction pipe extends through the inside of the condensing pipe.

18. The refrigerator according to claim 13, wherein a part of the suction pipe contacts the expansion member or the condensing pipe and is coiled together at a predetermined curvature.

19. A refrigerator comprising:

pipes connected to each other such that a refrigerant flowing toward an inlet of a compressor after passing through a vaporizer can be heat-exchanged but not mixed with a refrigerant passing through an expansion member and/or a refrigerant passed through a condenser.