WO2007040031A1

WO2007040031A1 - Liquid gas heat exchanger for air conditioner

Info

Publication number: WO2007040031A1
Application number: PCT/JP2006/318377
Authority: WO
Inventors: Takayuki Setoguchi; Makoto Kojima; Koji Nagasawa
Original assignee: Daikin Industries, Ltd.
Priority date: 2005-09-30
Filing date: 2006-09-15
Publication date: 2007-04-12
Also published as: JP2007093167A

Abstract

A liquid gas heat exchanger for an air conditioner capable of suppressing the rise of a suction pressure loss without adding a heat exchanger. In the liquid gas heat exchanger used in a refrigerating cycle for an air conditioner, a high pressure liquid pipe (7B) between a heat source side heat exchanger (3) and a user side heat exchanger (6) is formed by wrapping it around the outer periphery of the suction pipe (7A) of a compressor (1) to suppress the rise of the suction pressure loss.

Description

Specification

Liquid gas heat exchanger for air conditioner

Technical field

The present invention relates to a liquid gas heat exchanger for an air conditioner used in a refrigeration cycle for an air conditioner.

Background art

[0002] In a refrigeration cycle for an air conditioner in which a compressor, a heat source side heat exchanger, a pressure reducing mechanism, and a use side heat exchanger are sequentially connected by a refrigerant pipe, the heat source side heat exchanger and the use side A liquid-gas heat exchanger for air conditioners composed of a double-pipe heat exchanger consisting of a high-pressure liquid pipe between the heat exchanger ^^ and a compressor suction pipe has been proposed! reference). Patent Document 1: Japanese Patent Application Laid-Open No. 2005-83741.

Disclosure of the invention

Problems to be solved by the invention

By the way, as disclosed in Patent Document 1 above, a double pipe comprising a high pressure liquid pipe between a heat source side heat exchanger and the utilization side heat exchanger ^^ and a suction pipe of a compressor. When a heat exchanger is installed, the pressure loss of the heat exchanger itself increases the overall suction pressure loss, which may reduce the performance. In addition, a separate heat exchanger is added to the refrigerant circuit, and the machine room of the outdoor unit is compressed, resulting in a problem that the outdoor unit itself becomes large. The present invention has been made in view of the above points, and aims to be able to suppress an increase in suction pressure loss without adding new heat exchange.

Means for solving the problem

[0004] In the present invention, as a first means for solving the above-mentioned problem, air in which a compressor heat source side heat exchanger 3, a pressure reducing mechanism 4, and a use side heat exchanger 6 are sequentially connected by a refrigerant pipe 7 is used. The high-pressure liquid pipe 7B between the heat source side heat exchanger 3 and the use side heat exchanger 6 is compressed into the compressed air through the liquid gas heat exchanger for the air conditioner used in the refrigerating cycle for the air conditioner. It is constructed around the outer periphery of the suction pipe 7A of the machine 1.

By configuring as described above, the high pressure liquid pipe 7B is placed on the outer periphery of the suction pipe 7A of the compressor 1. By rotating, it is possible to suppress an increase in suction pressure loss. Therefore, it is possible to eliminate the COP drop as the entire refrigerant circuit. Since the existing suction pipe is also used, it is not necessary to install a separate heat exchanger and the outdoor unit can be compactly designed. Furthermore, by controlling the evaporator overheating in the liquid-gas heat exchanger, it is possible to take an accumulator, and further compact the outdoor unit.

[0005] In the present invention, as a second means for solving the above-mentioned problem, in the liquid gas heat exchanger provided with the first means, the cross-sectional area of the flow path of the high-pressure liquid pipe 7B. When the number of X passes is a and the flow path cross-sectional area of the suction pipe 7A is a, 0. OI K a / a <0.

1 2 1 2

It can also be set to 200, and in such a case, the liquid gas flow rate can be almost matched. As a result, by increasing the refrigerant flow rate and improving the condensation heat transfer rate, The performance of ^ can be improved, which contributes to the compactness of heat exchange ^^. In addition, since the refrigerant does not accumulate in the liquid gas heat exchanger, it is possible to suppress an increase in the amount of refrigerant charged in the system, and to provide an air conditioner that is environmentally friendly. This contributes to cost reduction. Here, 0.011 is the liquid gas density ratio of the refrigerant (eg, R410A) at −10 ° C., and 0.200 is the liquid gas density ratio of the refrigerant (eg, R410A) at 70 ° C. .

The invention's effect

[0006] According to the first means of the present invention, there is provided a refrigeration cycle for an air conditioner in which a compressor heat source side heat exchanger 3, a pressure reducing mechanism 4 and a use side heat exchanger 6 are sequentially connected by a refrigerant pipe 7. In the liquid gas heat exchanger for air conditioner used, the high-pressure liquid pipe 7B between the heat source side heat exchanger 3 and the use side heat exchange 6 is placed on the outer periphery of the suction pipe 7A of the compressor 1. Since it is configured to be wound so that the increase in suction pressure loss can be suppressed, there is an effect that it is possible to eliminate the COP decrease in the refrigerant circuit as a whole. However, since the existing suction pipe is used, there is no need to install a separate heat exchanger, and the outdoor unit can be compactly designed. Furthermore, by controlling the evaporator overheating in the liquid gas heat exchange, it is possible to take an accumulator, and there is an effect that further compaction of the outdoor unit is possible.

[0007] As in the second means of the present invention, a liquid gas heat exchanger provided with the first means is provided. The cross-sectional area of the high-pressure liquid pipe 7B is X, and the cross-sectional area of the suction pipe 7 断面

1

If the number of product X passes is α, it can be set to 0. OI K / a <0.200

2 1 2

In such a configuration, the liquid gas flow rate can be almost matched, and as a result, the heat exchange performance can be improved by increasing the refrigerant flow rate and improving the condensation heat transfer coefficient. This contributes to a compact heat exchange. In addition, since the refrigerant does not accumulate in the liquid-gas heat exchange, the increase in the amount of refrigerant charged in the system can be suppressed, and an environmentally friendly air conditioner can be provided. This also contributes to cost reduction.

Brief Description of Drawings

FIG. 1 is a front view showing a liquid gas heat exchanger according to an embodiment of the present invention.

FIG. 2 is a refrigerant circuit diagram showing a refrigeration system for an air conditioner according to the first embodiment of the present invention.

FIG. 3 is a refrigerant circuit diagram showing a refrigeration system for an air conditioner according to a second embodiment of the present invention.

FIG. 4 is a refrigerant circuit diagram showing a refrigeration system for an air conditioner according to a third embodiment of the present invention.

Explanation of symbols

[0009] 1 is a compressor

3 is the heat source side heat exchanger

4 is a decompression mechanism

4A is a heating decompression mechanism

4B is a cooling decompression mechanism

6 is the use side heat exchanger

7 is refrigerant piping

7A is the suction pipe

7B is a high-pressure liquid pipe

⁸ liquid-gas heat exchanger

BEST MODE FOR CARRYING OUT THE INVENTION [0010] Hereinafter, some preferred embodiments of the present invention will be described with reference to the accompanying drawings.

First embodiment

FIGS. 1 and 2 show a liquid gas heat exchanger useful for the first embodiment of the present invention and an air conditioner refrigeration cycle using the same.

As shown in FIG. 2, the air conditioner refrigeration cycle according to the present embodiment acts as a compressor 1, a four-way switching valve 2, a condenser during cooling operation, and as an evaporator during heating operation. Heat source side heat exchanger 3, heating decompression mechanism 4A, receiver 5, cooling decompression mechanism 4B and refrigerant on the use side heat exchange 6 that acts as an evaporator during cooling operation and acts as a condenser during heating operation 7 are sequentially connected. In this case, the compressor 1, the four-way switching valve 2, the heat source side heat exchanger 3, which acts as a condenser during cooling operation, and acts as an evaporator during heating operation, the decompression mechanism 4A for heating, the receiver 5, and the decompression for cooling The mechanism 4B is disposed in the outdoor unit, the use-side heat exchanger 6 is disposed in the indoor unit, and the heating decompression mechanism 4A and the cooling decompression mechanism 4B are fully opened during the cooling operation and the heating operation, respectively. It is constituted by an electronic expansion valve. A single pressure reducing mechanism 4 may be used instead of the heating pressure reducing mechanism 4A and the cooling pressure reducing mechanism 4B.

In the refrigeration cycle for an air conditioner having the above-described configuration, the refrigerant circulates as indicated by a solid line arrow during cooling operation and circulates as indicated by a dotted line arrow during heating operation. In the refrigeration cycle for an air conditioner having the above configuration, the heat source side heat exchange 3 that acts as a condenser during cooling operation or heating operation, respectively, 3 is the outlet of the use side heat exchanger 6 The refrigerant is subcooled, and the refrigerant circulation rate is increased by increasing the enthalpy difference on the use side heat exchange 6 or heat source side heat exchange 3 acting as an evaporator during cooling operation or heating operation, respectively. In order to improve the performance by reducing the pressure loss on the heat exchanger side acting as an evaporator, the suction pipe 7A of the compressor 1, the heat source side heat exchange 3 and the use side heat exchange 4 A liquid gas heat exchanger 8 for exchanging heat with the high-pressure liquid pipe 7B between the two is attached.

As shown in FIG. 1, the liquid gas heat exchanger 8 is connected directly to the suction pipe 7A of the compressor 1. The high pressure liquid pipe 7Β (in this embodiment, the heating decompressor

1 2

It is constructed by winding a high-pressure liquid pipe located between Structure 4 and Resino 5.

[0012] The flow passage cross-sectional area X of the high-pressure liquid pipe 7Β is a, and the flow passage cross-section X of the suction pipe 7Α is X

1

It is set so that 0. OI K a / a <0. 200, where α is the number of cells. In addition,

2 1 2

0.11 is the liquid gas density ratio of the refrigerant (eg, R410A) at −10 ° C., and 0.200 is the liquid gas density ratio of the refrigerant (eg, R410A) at 70 ° C.

In the liquid gas heat exchanger configured as described above, the following operation is obtained. That is, during the cooling operation, the gas refrigerant supplied from the compressor 1 through the four-way switching valve 2 to the heat source side heat exchanger 3 is condensed and liquefied in the heat source side heat exchange 3 and then fully opened. It enters the receiver 5 through the high pressure liquid pipe 7B constituting the pressure reducing mechanism 4A for heating and the liquid gas heat exchanger 8. The liquid refrigerant discharged from the receiver 5 is depressurized by the cooling decompression mechanism 4B to be in a gas-liquid mixed state, evaporated and vaporized by the use side heat exchanger 6, and constitutes the four-way switching valve 2 and the liquid gas heat exchanger 8. It is supposed to return to the compressor 1 through the suction pipe 7A. At this time, the cool air obtained by cooling the air blown to the use side heat exchanger 6 is provided for indoor cooling.

[0013] On the other hand, during heating operation, use side heat exchange from the compressor 1 through the four-way selector valve 2

The gas refrigerant supplied to 6 is condensed and liquefied in the use-side heat exchange 6 and then enters the receiver 5 via the cooling decompression mechanism 4B in the fully opened state. The liquid refrigerant coming out of the receiver 5 passes through the high-pressure liquid pipe 7B constituting the liquid gas heat exchanger 8 and is depressurized by the heating decompression mechanism 4A in the fully opened state to be in a gas-liquid mixed state, and the heat source side heat exchanger 3 Then, it evaporates and recirculates to the compressor 1 through the four-way switching valve 2 and the suction pipe 7A constituting the liquid gas heat exchanger 8. At this time, the warm air obtained by heating the air blown to the use-side heat exchanger 6 is used for indoor heating.

In the liquid gas heat exchanger 8 configured as described above, the high pressure liquid pipe 7Β is wound around the outer periphery of the suction pipe 7Α of the compressor 1 so as to function as a condenser during cooling operation or heating operation. Therefore, the heat on the side of the heat source 3 is used, and the refrigerant on the outlet side of the heat exchanger 6 on the use side is supercooled and used as an evaporator during cooling operation or heating operation. The heat exchanger on the heat source side heat exchanger 3 side increases the enthalpy difference on the heat source side and cools it. The performance can be improved by reducing the amount of circulating fluid and reducing the pressure loss on the heat exchange side that acts as an evaporator.

[0014] Further, since it is possible to suppress an increase in suction pressure loss, it is possible to eliminate a COP decrease as the entire refrigerant circuit. Since the existing suction pipe 7A is also used, there is no need to install a separate heat exchanger, and the outdoor unit can be compactly designed. Furthermore, by controlling the evaporator overheating in the liquid-gas heat exchanger 8, it is possible to remove the accumulator, and further compact the outdoor unit.

In the liquid gas heat exchanger 8, the cross-sectional area X of the high-pressure liquid pipe 7Β

1 Suction pipe cross-sectional area of 7mm When the number of passes X is α, 0. OI K a / a <0. 200

2 1 2

As a result, it is possible to almost match the liquid gas flow rate. As a result, it is possible to improve the heat exchange performance by increasing the refrigerant flow rate and improving the condensation heat transfer coefficient. This contributes to a compact heat exchange. Since the refrigerant does not accumulate in the liquid gas heat exchanger, the increase in the amount of refrigerant charged in the system can be suppressed, and an environmentally friendly air conditioner can be provided. It also contributes to cost reduction.

In the present embodiment, in the liquid gas heat exchanger 8, the straight pipe portion 7A of the suction pipe 7A,

1

The high pressure liquid pipe 7B is wound only around the outer circumference of 7A.

2

Of course, a high-pressure liquid pipe may be wound around the circumference.

Second embodiment

FIG. 3 shows a refrigeration system for an air conditioner that works well with the second embodiment of the present invention.

In this case, the high-pressure liquid pipe 7B constituting the liquid-gas heat exchanger 8 is a high-pressure liquid pipe between the receiver 5 and the cooling decompression mechanism 4 機構. Other configurations and operational effects are the same as those in the first embodiment, and thus description thereof is omitted.

Third embodiment

FIG. 4 shows a refrigeration system for an air conditioner that works well with the third embodiment of the present invention.

In this case, between the heat source side heat exchanger 3 and the use side heat exchanger 6, the heat source side heat exchanger 3 Alternatively, a flow path switching mechanism 9 is provided, which acts to flow the liquid refrigerant from the heat exchanger 6 on the use side to the receiver 5 and the decompression mechanism 7. The flow path switching mechanism 9 is configured by bridge-connecting four check valves 10, 11, 12, and 13. The liquid-gas heat exchanger 8 is configured by winding a high-pressure liquid pipe 7B between the flow path shelf structure 9 and the receiver 5 around a suction pipe 7A of the compressor 1. In this case, the high-pressure liquid refrigerant flowing in the high-pressure liquid pipe 7B constituting the liquid-gas heat exchanger 8 and the gas refrigerant flowing in the suction pipe 7Α are always in parallel flow. Since other configurations and operational effects are the same as those in the first embodiment, the description thereof is omitted. The present invention is not limited to the above-described embodiments, and does not depart from the gist of the invention. Of course, the design can be changed as appropriate.

Industrial applicability

The present invention can be widely used in the field of liquid gas heat exchangers for air conditioners used in refrigeration cycles for air conditioners.

Claims

The scope of the claims

[1] Refrigeration cycle for an air conditioner in which a compressor (1), a heat source side heat exchanger (3), a pressure reducing mechanism (4), and a use side heat exchanger (6) are sequentially connected by a refrigerant pipe (7) A liquid-gas heat exchanger for an air conditioner used in a high-pressure liquid pipe (7B) between the heat source side heat exchanger (3) and the use side heat exchanger (6). A liquid gas heat exchanger for an air conditioner, characterized by being wound around the outer periphery of the suction pipe (7A) of (1).

[2] Channel cross-sectional area of the high-pressure liquid pipe (7B) X is the number of passes, and channel cross-sectional area of the suction pipe (7A)

1

When the number of X passes is α, it is set so that 0. OI K / a <0.200.

2 1 2

The liquid gas heat exchanger for an air conditioner according to claim 2, wherein