JPH1068560A - Refrigeration cycle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the operating efficiency of a refrigeration cycle device by a method wherein a condenser is constituted so as to effect counterflow heat exchange and a refrigerant side flow passage is formed so that the number of outlet paths of refrigerant, which flows from a compressor into the condenser, becomes smaller than the number of inlet paths while mixed refrigerant is sealed into the refrigeration cycle device SOLUTION: During cooling operation, gas refrigerant, compressed by a scroll compressor 1 so as to have a high temperature and a high pressure, is introduced into an outdoor heat exchanger 3 through a four-way valve 2. In this case, the heat exchange of the gas refrigerant is effected with outdoor air through counterflow heat exchange while the refrigerant, branched into a larger number of inlet paths is being joined together into a smaller number of outlet paths, whereby the gas refrigerant dissipates heat and is condensed into liquid refrigerant. Further, the refrigerant, changed into liquid state by the condensing in the outdoor heat exchanger 3, is reduced in pressure in a throttling device 4 and, thereafter, is introduced into an indoor heat exchanger 5. The heat exchange of the refrigerant is effected in the indoor heat exchanger 5 with indoor air through parallel flow heat exchange while the refrigerant, branched into the smaller number of the inlet paths is being joined into the larger number of the outlet paths, whereby the refrigerant absorbs heat and is evaporated into the gas refrigerant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a refrigeration cycle apparatus using a mixed refrigerant as a refrigerant.

[0002]

2. Description of the Related Art Conventionally, HCFC22 has been widely used as a refrigerant for a refrigeration cycle apparatus including a compressor such as an air conditioner, a four-way valve, an outdoor heat exchanger, a throttle device, and an indoor heat exchanger. Its use is regulated to slightly destroy the stratospheric ozone layer, and a mixed refrigerant comprising a refrigerant containing no chlorine in the molecule has been attracting attention as an alternative refrigerant. Specifically, HFC32 / HFC125
HFC32 / HFC125
/ HFC134a is considered as a candidate.

[0003] The mixed refrigerant has a large or small temperature gradient under equal pressure in the two-phase region, and furthermore, in an actual refrigeration cycle apparatus, especially in a condenser, due to a pressure loss in the two-phase region, the mixed refrigerant has an equal temperature. The temperature drops during condensation with a large temperature gradient compared to the ideal temperature gradient under pressure. In the evaporator, the temperature rises smaller than the ideal temperature gradient due to the pressure loss.

[0004] Therefore, in a heat exchanger of a refrigeration cycle apparatus using a mixed refrigerant, it is a well-known technique to perform counter-flow heat exchange. There is a device in which the flow path on the refrigerant side is switched so that the refrigerant in the heat exchanger and the air exchange heat in opposite directions.

[0005]

However, the above-described device in an air conditioner having a four-way valve requires a complicated flow path on the refrigerant side, and strictly requires a heat exchanger with a small number of rows such as an air conditioner. The configuration cannot be such that the refrigerant and the air exchange heat in the opposite flow.

[0006] In any of the cooling and heating operations, when the flow path on the refrigerant side is configured so that the refrigerant and the air exchange heat in the opposite flow in any of the indoor and outdoor heat exchangers, the indoor and outdoor heat exchangers are operated in the opposite operation mode. In any of the exchangers, since the refrigerant and the air exchange heat in parallel, the operation efficiency may be extremely reduced.

That is, when a mixed refrigerant having a temperature gradient is used, there is no appropriate design method in designing a refrigeration cycle apparatus and a heat exchanger, and the actual situation is that it is configured by trial and error.

The present invention has been made in view of such a conventional refrigeration cycle apparatus, and in a refrigeration cycle apparatus using a mixed refrigerant, improvement of the operation efficiency of a refrigeration cycle apparatus having a scroll compressor has been realized. It is intended to do so.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and comprises a scroll compressor, a condenser having a plurality of rows, a throttle device, and an evaporator. In the refrigeration cycle device, the condenser is counterflow heat exchange, and the refrigerant-side flow path is configured such that the number of outlet paths of the refrigerant flowing from the compressor is smaller than the number of inlet paths,
The mixed refrigerant is sealed.

The present invention also provides a refrigeration cycle apparatus including a scroll compressor, a four-way valve, an outdoor heat exchanger, a throttle device, and an indoor heat exchanger. When the indoor heat exchanger is operated as a condenser, counterflow heat exchange is not performed, and the refrigerant-side flow path is configured so that the number of outlet paths of the refrigerant flowing from the compressor is smaller than the number of inlet paths, and mixing is performed. It is characterized in that a refrigerant is sealed.

Further, the present invention relates to a refrigeration cycle apparatus including a scroll compressor, a four-way valve, an outdoor heat exchanger, a throttle device, and an indoor heat exchanger. When operating the outdoor heat exchanger having fins as a condenser, counterflow heat exchange is performed, and the refrigerant-side flow path is configured so that the number of outlet paths of the refrigerant flowing from the compressor is smaller than the number of inlet paths, The mixed refrigerant is sealed.

That is, in the condenser in which the counter-flow heat exchange is performed, the flow path on the refrigerant side is configured so that the number of the outlet paths of the refrigerant flowing from the compressor is smaller than the number of the inlet paths. The temperature decreases from the inlet to the outlet of the condenser, and the temperature gradient from the inlet to the outlet of the condenser becomes convex upward. And the temperature difference between the refrigerant and the refrigerant can be minimized, which is effective in lowering the condensation pressure. Here, regardless of the high-pressure shell type and the low-pressure shell type, the scroll compressor has the characteristic that as the condensing pressure is lower, the compressor input can be reduced, so that it is possible to improve the operating efficiency. is there.

In a refrigeration cycle apparatus having a four-way valve, an outdoor heat exchanger serving as a condenser during cooling operation, and an indoor heat exchanger serving as a condenser during heating operation. it can. Therefore, it is possible to improve the operation efficiency of the cooling and heating operation by utilizing the characteristics of the scroll compressor.

Further, in the outdoor heat exchanger which becomes a condenser during the cooling operation, a plurality of rows and independent fins are formed for each row, so that the effect of the counter-flow heat exchange is enhanced during the cooling operation, and the condensing pressure is increased. In the outdoor heat exchanger that becomes an evaporator during the heating operation, the number of inlet paths of the refrigerant flowing from the expansion device during the heating operation is small. In addition, it is possible to form the evaporation temperature as uniform as possible from the tendency of the pressure loss, and there is also a secondary effect of realizing uniform frost formation during the heating operation.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an air conditioner according to an embodiment of the present invention. In FIG. 1, 1 is a scroll compressor, 2
Is a four-way valve for switching between cooling operation and heating operation, 3 is an outdoor heat exchanger, 4 is a throttle device, and constitutes an outdoor unit A together with these and an outdoor fan (not shown). Reference numeral 5 denotes an indoor heat exchanger, which forms an indoor unit B from an indoor fan (not shown) and the like. As the refrigerant, a mixed refrigerant composed of a refrigerant containing no chlorine in the molecule is sealed. Here, the finned outdoor heat exchanger 3 having a plurality of rows is
Fins attached to a plurality of rows are cut off independently, and outdoor air is introduced into the outdoor heat exchanger 3 by an outdoor fan (not shown) in a direction indicated by a dashed line in FIG. The pipe connected to the four-way valve 2 is connected to the side, the pipe connected to the expansion device 4 is connected to the air inlet side,
Thus, during the cooling operation, the refrigerant introduced into the outdoor heat exchanger 3 in the direction of the solid line arrow in FIG. 1 and the air introduced into the outdoor heat exchanger 3 in the direction of the alternate long and short dash line in FIG. The refrigerant-side flow path is configured so that the number of outlet passes of the refrigerant flowing from the scroll compressor 1 is smaller than the number of inlet passes. Further, in the indoor heat exchanger 5 with fins having a plurality of rows, the fins provided for the plurality of rows are separated independently, and an indoor fan (not shown) shown in FIG.
The indoor air flows into the indoor heat exchanger 5 in the
The pipe connected to the four-way valve 2 is connected to the outlet side of the air, and the pipe connected to the expansion device 4 is connected to the inlet side of the air. Thus, during the heating operation, in the direction of the dotted arrow in FIG. The refrigerant introduced into the indoor heat exchanger 5 and the air introduced into the indoor heat exchanger 5 in the direction of an alternate long and short dash line in FIG. The refrigerant-side flow path is configured to be larger than the number of inlet paths.

The operation of the air conditioner having the above configuration will be described. First, during the cooling operation, the four-way valve 2 is set as shown by the solid line in FIG. Then, the gas refrigerant which has been compressed by the scroll compressor 1 to have a high temperature and a high pressure is introduced into the outdoor heat exchanger 3 through the four-way valve 2. Here, the gas refrigerant is counter-flow heat-exchanged with outdoor air while the refrigerant branched into a large inlet path is joined to a small outlet path, and radiates heat to condense into a liquid refrigerant. Further, the refrigerant condensed in the outdoor heat exchanger 3 to be in a liquid state is decompressed by the expansion device 4 to be in a low-temperature and low-pressure two-phase state, and is introduced into the indoor heat exchanger 5. In the indoor heat exchanger 5, the low-temperature and low-pressure two-phase refrigerant is exchanged with the indoor air in parallel flow while being joined to the outlet path containing a large amount of refrigerant branched from the small number of inlet paths. It becomes a refrigerant. Further, the refrigerant evaporated into a gas state in the indoor heat exchanger 5 is introduced into the scroll compressor 1 through the four-way valve 2.

Next, during the heating operation, the four-way valve 2 is set as shown by a dotted line in FIG. Then, the gas refrigerant which has been compressed by the scroll compressor 1 to have a high temperature and a high pressure is introduced into the indoor heat exchanger 5 through the four-way valve 2. Here, the gas refrigerant undergoes counter-current heat exchange with the indoor air while being joined to the outlet path where the refrigerant branched into the large inlet path and the small refrigerant is diverted, condenses and becomes a liquid refrigerant. Further, the refrigerant condensed in the indoor heat exchanger 5 to be in a liquid state is decompressed by the expansion device 4 to be in a low-temperature and low-pressure two-phase state, and is introduced into the outdoor heat exchanger 3. In the outdoor heat exchanger 3, the low-temperature and low-pressure two-phase refrigerant is exchanged with the outdoor air in parallel flow while being joined to the outlet path where the refrigerant branched from the small inlet path is large. It becomes a low-pressure gas refrigerant. Furthermore, the outdoor heat exchanger 3
The refrigerant which has been evaporated to a low-temperature and low-pressure gas state through the four-way valve 2 is introduced into the scroll compressor 1.

The operation state when the mixed refrigerant is used will be described with reference to the temperature-entropy diagram of FIG. The operating state during the cooling operation is shown in FIG. 2- (a), and the operating state during the heating operation is shown in FIG. 2- (b). In both cooling and heating operations, during the condensation process, due to pressure loss,
The temperature drops with a large temperature gradient. In the evaporation process, when the ideal temperature gradient is large, the temperature rises even if there is a pressure loss, and conversely, when the ideal temperature gradient is small, the temperature decreases due to the pressure loss. The former example is shown.

In the outdoor heat exchanger 3 during the cooling operation, the number of passes is branched at the inlet side, so that the pressure loss at the inlet side is reduced, and the temperature drop at the inlet side of the condenser is suppressed. The temperature gradient from the inlet to the outlet of the condenser has an upwardly convex shape, and in the outdoor heat exchanger 3 in which the counterflow heat is exchanged in the independent fins, the temperature difference between the air and the refrigerant at the refrigerant outlet side can be minimized. . Here, the reason for merging into a small number of passes on the outlet side of the outdoor heat exchanger 3 is that although the pressure loss increases on the outlet side, the refrigerant-side condensation heat transfer rate decreases on the outlet side and increases the flow rate of the refrigerant. This is to improve the heat exchange efficiency as uniformly as possible throughout the condenser. For this reason, the condensing pressure can be greatly reduced, and this contributes particularly to an improvement in the operation efficiency of the refrigeration cycle apparatus having the scroll compressor 1.

On the other hand, in the indoor heat exchanger 5 during the cooling operation,
Since the number of passes on the inlet side is small, the pressure loss on the inlet side increases, the temperature rise on the inlet side of the evaporator is suppressed, and the temperature gradient from the inlet to the outlet of the evaporator becomes concave upward, In the indoor heat exchanger 5 where parallel flow heat exchange is performed in the independent fins, the temperature difference between the air and the refrigerant at the outlet side of the refrigerant is the smallest. Here, the reason for branching into a large number of passes at the outlet side of the indoor heat exchanger 5 is to reduce the pressure loss at the outlet side and increase the refrigerant-side evaporation transmissibility at the inlet side to increase the flow rate of the refrigerant, thereby evaporating the refrigerant. This is to improve the heat exchange efficiency as uniformly as possible over the entire vessel. Here, since the evaporating pressure is slightly lower than in the case of the counter-flow heat exchange, the operation efficiency becomes a negative factor.

Conversely, in the indoor heat exchanger 5 during the heating operation, the number of passes is branched at the inlet side, so that the pressure loss at the inlet side is reduced and the temperature drop at the inlet side of the condenser is suppressed. The temperature gradient from the inlet to the outlet of the condenser has an upwardly convex shape, and in the indoor heat exchanger 5 in which counterflow heat exchange is performed in independent fins, the temperature difference between the air and the refrigerant at the refrigerant outlet side is minimized. Can be smaller. Here, the reason for merging with a small number of passes on the outlet side of the indoor heat exchanger 5 is that although the pressure loss increases on the outlet side, the refrigerant-side condensation heat transfer rate decreases on the outlet side and increases the flow rate of the refrigerant. This is to improve the heat exchange efficiency as uniformly as possible throughout the condenser. For this reason, the condensing pressure can be greatly reduced, and this contributes particularly to an improvement in the operation efficiency of the refrigeration cycle apparatus having the scroll compressor 1.

On the other hand, in the outdoor heat exchanger 3 during the heating operation,
Since the number of passes on the inlet side is small, the pressure loss on the inlet side increases, the temperature rise on the inlet side of the evaporator is suppressed, and the temperature gradient from the inlet to the outlet of the evaporator becomes concave upward, In the outdoor heat exchanger 3 in which the independent fins exchange heat in parallel, the temperature difference between the air and the refrigerant at the refrigerant outlet side is the smallest. Here, the reason for branching into a large number of passes on the outlet side of the outdoor heat exchanger 3 is that the pressure loss is reduced on the outlet side, the refrigerant-side evaporation transmissibility that decreases on the inlet side is increased, and the flow rate of the refrigerant is increased. This is to improve the heat exchange efficiency as uniformly as possible over the entire vessel. Here, since the evaporating pressure is slightly lower than in the case of the counter-flow heat exchange, the operation efficiency becomes a negative factor.

In the example of FIG. 2, the case where the ideal temperature gradient is large in the evaporation process is shown, so that the temperature rises even if there is a pressure loss, and the inlet side of the outdoor heat exchanger 3 during the heating operation has the lowest temperature. Becomes Conversely, when the ideal temperature gradient is small, although not shown, the temperature drops due to pressure loss, and the outlet side of the outdoor heat exchanger 3 during the heating operation has the lowest temperature. Since the outdoor heat exchanger 3 is configured such that the number of outlet paths of the refrigerant flowing from the scroll compressor 1 during the cooling operation is smaller than the number of inlet paths, the outdoor heat exchanger 3 flows in from the expansion device 4 during the heating operation. Since the number of refrigerant inlet paths is small, it is possible to form as uniform an evaporation temperature as possible due to the tendency of pressure loss, and also has a secondary effect of realizing uniform frost formation during heating operation.

FIG. 3 shows the characteristics of the scroll compressor 1 in which the abscissa represents the evaporating pressure, the ordinate represents the compressor input, and the condensing pressure as a parameter. The scroll compressor 1 has a characteristic that it hardly depends on the evaporation pressure regardless of the high-pressure shell type and the low-pressure shell type, and the compressor input can be reduced as the condensation pressure is lower. For this reason, as the refrigeration cycle device, the operating characteristics that the condensing pressure is greatly reduced and the evaporating pressure is slightly reduced are effective in reducing the input of the scroll compressor 1, and the operating efficiency is improved. Is possible.

[0026]

As described above, in the refrigeration cycle apparatus according to the present invention, the condenser is provided with counter-flow heat exchange, and the number of outlet paths of the refrigerant flowing from the compressor is made smaller than the number of inlet paths. Since the flow path is formed and the mixed refrigerant is sealed, the pressure loss at the inlet side is reduced, the temperature drop at the inlet side of the condenser is suppressed, and the temperature gradient from the inlet to the outlet of the condenser is convex. In the condenser in which counterflow heat exchange is performed, the temperature difference between the air and the refrigerant at the refrigerant outlet side can be minimized, the condensing pressure can be greatly reduced, and the operation efficiency can be improved. Things.

In the refrigeration cycle apparatus according to the present invention,
When the outdoor heat exchanger having a plurality of rows and / or the indoor heat exchanger is operated as a condenser, counterflow heat exchange is not performed, and the number of outlet passes of the refrigerant flowing from the compressor is smaller than the number of inlet passes. Since the refrigerant-side flow path is formed and the mixed refrigerant is sealed, the outdoor heat exchanger serving as a condenser during the cooling operation, and the indoor heat exchanger serving as the condenser during the heating operation. This can greatly reduce the temperature, and can improve the operation efficiency of the cooling and heating operation.

Further, in the refrigeration cycle apparatus according to the present invention, when an outdoor heat exchanger having a plurality of rows and independent fins for each row is operated as a condenser, counterflow heat exchange is not performed, and refrigerant flowing from the compressor is used. The flow path on the refrigerant side is configured so that the number of outlet passes is smaller than the number of inlet passes, and the mixed refrigerant is sealed, so that during cooling operation, the effect of counterflow heat exchange can be enhanced and the condensing pressure can be greatly reduced. Becomes
In the outdoor heat exchanger that improves the operation efficiency during the cooling operation and becomes the evaporator during the heating operation, the number of inlet paths of the refrigerant flowing from the expansion device during the heating operation is small, and as much as possible due to the tendency of pressure loss, It is possible to form the evaporation temperature, and also has a secondary effect of realizing uniform frost during the heating operation.

[Brief description of the drawings]

FIG. 1 is a schematic circuit diagram of a refrigeration cycle device according to an embodiment of the present invention.

FIG. 2 is a temperature-entropy diagram in the refrigeration cycle apparatus according to one embodiment of the present invention.

FIG. 3 is an explanatory diagram of input characteristics of a scroll compressor which is a component of the refrigeration cycle device according to one embodiment of the present invention.

[Explanation of symbols]

 1: scroll compressor 2: four-way valve 3: outdoor heat exchanger 4: throttle device 5: indoor heat exchanger A: outdoor unit B: indoor unit

Claims (3)

[Claims] A scroll compressor, a condenser having a plurality of rows, a throttling device, and an evaporator, wherein the condenser performs counter-flow heat exchange, and an outlet for a refrigerant flowing from the compressor. A refrigeration cycle apparatus, wherein a refrigerant-side flow path is configured so that the number of passes is smaller than the number of inlet passes, and a mixed refrigerant is sealed. 2. A scroll compressor, a four-way valve, an outdoor heat exchanger having a plurality of rows, a throttle device, and an indoor heat exchanger, wherein the outdoor heat exchanger and / or the indoor heat exchanger is provided. When operating as a condenser, there is no countercurrent heat exchange,
A refrigeration cycle apparatus wherein a refrigerant-side flow path is configured so that the number of outlet passes of the refrigerant flowing from the compressor is smaller than the number of inlet passes, and a mixed refrigerant is sealed. 3. An outdoor heat exchanger comprising a scroll compressor, a four-way valve, an outdoor heat exchanger having a plurality of rows and independent fins for each row, a throttle device, and an indoor heat exchanger. When operating as a condenser, counterflow heat exchange is performed, the refrigerant side flow path is configured so that the number of outlet paths of the refrigerant flowing from the compressor is smaller than the number of inlet paths, and the mixed refrigerant is sealed. A refrigeration cycle device characterized by the above-mentioned.