JPH109718A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need of particular provision of a pressure reduce by providing with a pressure reducing function a site-laid refrigerant piping connecting between an outdoor heat exchanger and an indoor heat exchanger. SOLUTION: In cooling operation, a four-way valve 2 is operated into a state where connection ports A and D, B and C thereof are interlly connected. High temperature high pressure refrigerant vapor discharged from the compressor 1 flows onto the outdoor heat exchanger 3 after passage through the connection ports A, D, and radiates heat to outdoor air sent form an outdoor fan 8. The refrigerant which has radiated the heat is condensed and liquefied into a liquid refrigerant, and enters a refrigerant liquid connection piping 4. Herein, the refrigerant liquid connection piping 4 is reduced in pressure under the indications that the piping 4 is provided with a pressure reducing function, and becomes a two phase flow of gas/liquid mixture. The low temperature low pressure refrigerant as the two phase flow is guided to an indoor machine, and enters an indoor heat exchanger 6 to effect heat exchange with indoor air sent from the indoor fan 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an air conditioner.

[0002]

2. Description of the Related Art Heretofore, it has been general that an air conditioner is configured by using a cheapest capillary tube as a decompression device of a refrigeration cycle. Another conventional air conditioner has a function of adjusting the pressure reduction amount using an electric expansion valve as described in Japanese Patent Application Laid-Open No. 60-226667. In another conventional air conditioner, as described in Japanese Patent Application No. 5-2570, the pressure of the liquid refrigerant is temporarily reduced by a capillary tube as a first pressure reducing device to convert the liquid refrigerant into a gas-liquid two-phase flow. There is also a refrigeration cycle that can reduce the amount of refrigerant even if the refrigerant pipe connected locally is long by reducing the pressure with an electric expansion valve that is a pressure reducing device.

[0003]

When the pressure reducing device is constituted by a capillary tube, it is relatively inexpensive, but on the other hand, the diameter of the refrigerant liquid connection pipe at the site is increased in order to keep the state of the refrigerant at the inlet of the capillary tube in the liquid phase. There is a need to. As a result, the amount of refrigerant in the connection pipe becomes large, and it cannot be said that the whole system including the local construction is inexpensive. In addition, since the amount of the refrigerant corresponding to the length of the connection pipe at the site is charged, a large error in the amount of the charged refrigerant is likely to occur, and the refrigeration cycle tends to be unstable due to the influence.

In order to stabilize the refrigerating cycle, there is a structure in which the pressure reducing device can change the flow rate of the refrigerant by an electric expansion valve or the like instead of the capillary tube. However, this has a significant cost problem. I will.

In order to reduce the amount of the refrigerant, there is also a configuration in which the refrigerant is once depressurized by a capillary tube to form a gas-liquid two-phase flow, thereby reducing the amount of the refrigerant in the local refrigerant liquid connection pipe. In the case of the cooling / heating machine, a check valve is required to bypass the capillary tube during the heating operation.

[0006]

In order to solve the above-mentioned problems, the present invention provides an air conditioner including a refrigeration cycle in which a compressor, an outdoor heat exchanger, an indoor heat exchanger, and an accumulator are connected in order by a refrigerant pipe. The apparatus is characterized in that a refrigerant pipe on the site connecting the outdoor heat exchanger and the indoor heat exchanger has a pressure reducing function.

Further, by using an electric expansion valve together, the flow rate of the refrigerant may be adjusted so as to absorb the difference in the refrigerant pipe at the site.

Further, the present invention is characterized in that the pressure is reduced under the influence of the refrigerant pipe only when the local refrigerant pipe is long, and the amount of refrigerant in the liquid refrigerant pipe is reduced.

[0009] The configuration in which the local refrigerant pipe has a decompression function includes, for example: (1) connecting a rapidly reduced pipe in the middle of the local refrigerant liquid connection pipe (locally supplied or attached to the product);

[0010] The diameter of the on-site refrigerant liquid connection pipe is changed according to the length of the pipe.

[0011] These are not specified here.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a system diagram of an air conditioner showing a first embodiment of the present invention. Although not particularly specified, an example of a cooling / heating device will be described here. The illustrated refrigeration cycle includes an indoor unit including the compressor 1 and an outdoor unit connected to the indoor unit.

The indoor unit comprises a compressor 1 for compressing refrigerant vapor.
A four-way valve 2 arranged with its first connection port A connected to a discharge port of the compressor 1; and an indoor heat exchanger 6 having one end connected to a second connection port B of the four-way valve 2. It is composed of On the other hand, the suction side of the compressor 1 is
And an indoor blower 9 that connects the inlet side to the third connection port C of the four-way valve 2 and blows indoor air to the indoor heat exchanger 6.

The outdoor unit includes an outdoor blower 8 for blowing outside air to the outdoor heat exchanger 3.

The indoor unit and the outdoor unit are locally connected to the indoor heat exchanger 6 and the outdoor heat exchanger 3 by the refrigerant liquid connection pipe 4, and the outdoor heat exchanger 3 and the fourth connection port D of the four-way valve 2 are connected to each other. Each is connected by a refrigerant gas connection pipe 5.

Next, the operation of this embodiment will be described.

During the cooling operation, the four-way valve 2 is operated such that the connection ports A and D, and B and C respectively communicate internally. The solid arrows in the drawing indicate the direction of the flow of the refrigerant during the cooling operation. The high-temperature and high-pressure refrigerant vapor discharged from the compressor 1 flows into the outdoor heat exchanger 3 through the connection ports A and D of the four-way valve 2 and releases heat to the outdoor air blown by the outdoor blower 8. The refrigerant that has released heat to the outdoor air is condensed and liquefied to become a liquid refrigerant, and flows into the refrigerant liquid connection pipe 4.
At this time, the refrigerant liquid connection pipe 4 is decompressed on condition that a pipe having a decompression function is adopted, and becomes a two-phase flow of gas-liquid mixing. The decompression function is, for example, (1) connecting a rapidly reduced pipe in the middle of the on-site refrigerant liquid connection pipe 4. This has the function of an orifice.

(2) As an alternative to (1), the entire diameter of the on-site refrigerant liquid connection pipe 4 is reduced. This also provides the same effect as (1). Further, it is also possible to select the pipe diameter according to the installation location of the indoor unit and the outdoor unit (pipe connection length and height difference).

There are no particular restrictions here.

The low-temperature, low-pressure refrigerant that has become a two-phase flow of gas-liquid mixture is guided to the indoor unit, flows into the indoor heat exchanger 6, and exchanges heat with the indoor air blown by the indoor blower 9. The refrigerant that has been cooled by cooling the indoor air by heat exchange with the indoor air is evaporated by the heat of the indoor air into refrigerant vapor, and the four-way valve 2
And enters the accumulator 7 through the connection ports B and C, and then returns to the compressor 1.

During the heating operation, the four-way valve 2 is operated such that the connection ports A and B, and C and D respectively communicate internally. As a result, the refrigerant flows in the opposite direction to that during the cooling operation, and heat is released by releasing heat to the indoor air blown by the indoor blower 9. The dashed arrow in the figure indicates the direction of the flow of the refrigerant during the heating operation.

Next, FIG. 2 is a system diagram of an air conditioner showing a second embodiment of the present invention.

In the second embodiment shown in this figure, of the refrigerant pipes connecting the indoor unit and the outdoor unit on site, the refrigerant liquid connection pipe 4 has a decompression function, and the capillary tube 10 is installed as a decompression device. It is configured to be.

In the second embodiment, during the cooling operation, the pressure is reduced by the on-site refrigerant liquid connection pipe 4 and further reduced by the capillary tube 10 of the indoor unit. In the case of distance, refrigerant will flow into two phases,
Works to reduce refrigerant holdings. Conversely, when the refrigerant liquid connection pipe 4 is short, the amount of refrigerant to be charged at the site can be adjusted. However, the chargeless cycle (the required amount of refrigerant at the longest distance is charged in advance and the In a refrigeration cycle that does not require a filling operation, the amount of gas-phase refrigerant occupying the refrigerant liquid connection pipe 4 is small due to the short distance even if the pipe diameter is the same as or larger than that in the case of long distance, and conversely surplus A refrigerant can be held in the refrigerant liquid connection pipe 4. This is an effective means that can reduce the capacity of the container (accumulator 7 in the present embodiment) that holds the surplus refrigerant.

The other structure and operation of the second embodiment are the same as those of the first embodiment.

FIG. 3 is a system diagram of an air conditioner showing a third embodiment of the present invention.

In the third embodiment shown in this figure, the refrigerant liquid connecting pipe 4 among the refrigerant pipes connecting the indoor unit and the outdoor unit on site has a pressure reducing function, and the electric expansion valve 11 is used as a pressure reducing device. Is configured to be installed.

In the third embodiment, the pressure is reduced at the local refrigerant liquid connection pipe 4 during the cooling operation, and further reduced by the electric expansion valve 11 of the indoor unit. This is because when the refrigerant liquid connection pipe 4 is a long distance, the refrigerant flows into two phases and works to reduce the refrigerant holding amount.
Work to make fine adjustments. In the case of a short distance, as in the second embodiment, the amount of pressure reduction by the refrigerant liquid connection pipe 4 decreases, and the amount of refrigerant occupying the refrigerant liquid connection pipe 4 increases. The amount of reduced pressure can be adjusted. Also, it may be adjusted by the amount of refrigerant charged locally,
In the chargeless cycle, the same effect as in the second embodiment can be obtained. Further, in the present embodiment, in addition to the difference in the length of the refrigerant pipe at the site, the difference in the amount of refrigerant required for the cooling operation and the heating operation can be adjusted by the electric expansion valve 11. Further, the electric expansion valve 11 can adjust fluctuations in the operating state during cooling or heating, for example, fluctuations in the pressure of the refrigeration cycle caused by fluctuations in the indoor or outdoor air temperature and the air flow rate. Further, in the defrosting operation at the time of the heating operation, it is general to perform the reverse cycle defrosting that returns the operation of the four-way valve 2 at the time of the cooling operation, but the optimal pressure reduction amount at this time is determined by the electric expansion valve 11. It can also be adjusted.

The other structure and operation of the third embodiment are the same as those of the first embodiment.

[0031]

According to the first aspect of the present invention, the decompression mechanism in the refrigeration cycle of the air conditioner is provided on the site to the refrigerant liquid pipe connecting the indoor unit and the outdoor unit, and the decompression device is specially provided. There is no need to equip.

According to the second aspect of the present invention, the state of the refrigerant in the refrigerant liquid pipe connecting the indoor unit and the outdoor unit is changed to a gas-liquid two-phase flow, and the amount of the required refrigerant is reduced. The conditioner can be achieved without specially requiring a pressure reducing device for two-phase flow (including a check valve which bypasses the device during heating in the case of a cooling / heating device).

Further, according to the third aspect of the present invention, if an electric expansion valve whose opening can be freely changed is used, the distance of the refrigerant pipe connecting the indoor unit and the outdoor unit can be reduced. In addition, a stable refrigeration cycle can be configured even in a chargeless cycle that does not require refrigerant charging on site,
Since the excess refrigerant in the case where the distance of the refrigerant pipe is short can be stored in the liquid pipe, it is possible to reduce the capacity of a vessel that conventionally has the refrigerant.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a refrigeration cycle of an air conditioner according to a first embodiment of the present invention.

FIG. 2 is a system diagram showing a refrigeration cycle of an air conditioner according to a second embodiment of the present invention.

FIG. 3 is a system diagram showing a refrigeration cycle of an air conditioner according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Four-way valve, 3 ... Outdoor heat exchanger, 4 ... Refrigerant liquid connection piping, 5 ... Refrigerant gas connection piping, 6 ... Indoor heat exchanger, 7 ... Accumulator, 8 ... Outdoor blower, 9 ... indoor side blower, 11 ... electric expansion valve.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiromi Kawaguchi 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Within Hitachi Shimizu Engineering Co., Ltd.

Claims (1)

[Claims] 1. An air conditioner comprising a refrigeration cycle in which a compressor, an outdoor heat exchanger, an indoor heat exchanger, and an accumulator are sequentially connected by a refrigerant pipe, wherein the outdoor heat exchanger and the indoor heat exchanger are provided. An air conditioner characterized by having a decompression function in a local refrigerant pipe connecting the air conditioner.