JP2611351B2 - Refrigeration cycle - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a refrigerating cycle used for a cooling device or a refrigerating device such as a car air conditioner or a room air conditioner.

[Prior Art] Conventionally, in order to improve the performance of a heat exchanger used in a refrigeration cycle, a heat exchanger including a gas-liquid separator having a double pipe structure has been devised.

In this gas-liquid separator, since the flow of the refrigerant becomes an annular flow during the heat exchange of the heat exchanger, the annular flow portion is formed into a double pipe structure, and the gas refrigerant flowing through the inner passage and the liquid flowing through the outer passage are formed. It separates from the refrigerant.

Therefore, when the gas-liquid separator is provided in the refrigerant condenser,
The liquid refrigerant condensed and liquefied during the heat exchange of the refrigerant condenser is extracted by the gas-liquid separator, and the heat exchange efficiency of the refrigerant condenser can be improved by using only the gas refrigerant before condensation in the refrigerant condenser. .

The liquid refrigerant extracted by the gas-liquid separator is guided to the receiver together with the liquid refrigerant condensed and liquefied by the refrigerant condenser.

Further, when the gas-liquid separator is provided in the refrigerant evaporator, the gas refrigerant evaporated during the heat exchange of the refrigerant evaporator is extracted by the gas-liquid separator, and the inside of the refrigerant evaporator is combined with only the liquid refrigerant before evaporation. By doing so, the heat exchange efficiency of the refrigerant evaporator can be improved.

The gas refrigerant extracted by the gas-liquid separator is sucked into the refrigerant compressor together with the gas refrigerant evaporated by the refrigerant evaporator.

Thus, the performance of the heat exchanger can be improved by providing the gas-liquid separator during the heat exchange of the heat exchanger. As a result, it is possible to reduce the size of the heat exchanger or to increase the capacity of the heat exchanger if the size is the same.

[Problems to be Solved by the Invention] However, in the gas-liquid separator as described above, it is difficult to completely separate the gas refrigerant and the liquid refrigerant due to the structure of the gas-liquid separator. Therefore, on the refrigerant condenser side, the superheated gas is mixed with the liquid refrigerant extracted by the gas-liquid separator and guided to the receiver, and the liquid refrigerant in the receiver is re-evaporated.

Also, on the refrigerant evaporator side, the liquid refrigerant is mixed with the gas refrigerant extracted from the gas-liquid separator and is sucked into the refrigerant compressor, and the refrigerant compressor may be damaged by liquid compression, and at the same time,
There was a problem that the cycle efficiency was reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a refrigeration cycle in which liquid refrigerant and gas refrigerant extracted by a gas-liquid separator are completely liquefied and gasified to improve cycle efficiency. It is in.

[Means for Solving the Problems] In order to achieve the above object, the present invention employs the following technical means.

A refrigerant compressor that compresses and discharges the sucked gas refrigerant;
A refrigerant condenser for condensing and liquefying the high-pressure refrigerant discharged from the refrigerant compressor, a decompression device for adiabatically expanding the refrigerant supplied from the refrigerant condenser, and a refrigerant for evaporating the refrigerant adiabatically expanded by the decompression device An evaporator, which is provided in the middle of heat exchange between the refrigerant condenser, separates a gas refrigerant before condensation and a liquid refrigerant after condensation, extracts the separated liquid refrigerant, supplies the separated liquid refrigerant to the decompression device, and separates the liquid refrigerant. A first gas-liquid separator that allows the discharged gas refrigerant to flow into a downstream portion of the refrigerant condenser, and is provided in the middle of heat exchange between the refrigerant evaporator and separates the liquid refrigerant before evaporation from the gas refrigerant after evaporation. A second gas-liquid separator that extracts the separated gas refrigerant and supplies it to the refrigerant compressor, and allows the separated liquid refrigerant to flow into a downstream portion of the refrigerant evaporator; and the first gas-liquid separator. Liquid cooling which is extracted and led to the decompression device Characterized by comprising the said second gas-liquid separator refrigerant heat exchanger for heat exchange between the gas refrigerant is extracted guided to the refrigerant compressor through.

[Operation] The liquid refrigerant separated by the first gas-liquid separator is supplied from the first gas-liquid separator to the pressure reducing device, and the separated gas refrigerant is transferred from the first gas-liquid separator to a downstream portion of the refrigerant condenser. Inflow. On the other hand, the gas refrigerant separated by the second gas-liquid separator is supplied from the second gas-liquid separator to the refrigerant compressor, and the separated liquid refrigerant is transferred from the second gas-liquid separator to a downstream portion of the refrigerant evaporator. Inflow.

The liquid refrigerant introduced from the first gas-liquid separator to the pressure reducing device and the second refrigerant
The gas refrigerant guided from the gas-liquid separator to the refrigerant compressor undergoes heat exchange in the refrigerant heat exchanger. Here, the liquid refrigerant extracted by the first gas-liquid separator includes a superheated gas that is not liquefied, and the gas refrigerant extracted by the second gas-liquid separator includes an unevaporated liquid refrigerant. In addition, the temperature of the liquid refrigerant extracted by the first gas-liquid separator is higher than that of the gas refrigerant extracted by the second gas-liquid separator. Therefore, the liquid refrigerant extracted by the first gas-liquid separator and the gas refrigerant extracted by the second gas-liquid separator undergo heat exchange in the refrigerant heat exchanger, so that the superheated gas contained in the liquid refrigerant becomes The liquid refrigerant which is condensed and liquefied, and which is not evaporated, contained in the gas refrigerant evaporates and is gasified.

As a result, the liquid refrigerant containing the superheated gas extracted from the refrigerant condenser by the first gas-liquid separator is completely liquefied and supplied to the decompression device, and is not extracted from the refrigerant evaporator by the second gas-liquid separator. The gas refrigerant including the liquid refrigerant for evaporation is completely gasified and sucked into the refrigerant compressor.

On the other hand, the gas refrigerant separated by the first gas-liquid separator is
After flowing in the refrigerant condenser downstream of the gas-liquid separator and being condensed and liquefied, the liquid refrigerant supplied to the decompression device and separated by the second gas-liquid separator is downstream of the second gas-liquid separator. After flowing through the refrigerant evaporator and evaporating, the refrigerant is sucked into the refrigerant compressor.

[Effects of the Invention] According to the present invention, the liquid refrigerant containing the superheated gas extracted by the first gas-liquid separator and the gas refrigerant containing the unevaporated liquid refrigerant extracted by the second gas-liquid separator are cooled by the refrigerant heat. By performing heat exchange in the exchanger, the liquid refrigerant containing the superheated gas can be completely liquefied, and the gas refrigerant containing the unevaporated liquid refrigerant can be completely gasified. Thereby, it is possible to prevent the superheated gas from flowing into the receiver, to prevent the liquid refrigerant in the receiver from being re-evaporated, and to prevent the liquid refrigerant from being sucked into the refrigerant compressor, Damage to the refrigerant compressor due to liquid compression can be prevented.

Further, the liquid refrigerant extracted from the refrigerant condenser by the first gas-liquid separator and the gas refrigerant extracted from the refrigerant evaporator by the second gas-liquid separator can be completely liquefied and gasified, thereby reducing the efficiency of the refrigeration cycle. Can be prevented.

Embodiment Next, a refrigeration cycle of the present invention applied to an air conditioner for a vehicle will be described based on an embodiment shown in the drawings.

 FIG. 1 shows a refrigerant circuit diagram of a refrigeration cycle.

The refrigeration cycle 1 of the present embodiment includes a refrigerant compressor 2, a refrigerant condenser 3, a receiver 4, an expansion valve 5, which is a decompression device of the present invention, and a refrigerant evaporator 6;
A first gas-liquid separator 7 for extracting a liquid refrigerant during the heat exchange of the second and a second gas-liquid separator 8 for extracting a gas refrigerant during the heat exchange of the refrigerant evaporator 6, and a liquid refrigerant extracted from the refrigerant condenser 3. And a refrigerant heat exchanger 9 for exchanging heat with the gas refrigerant extracted from the refrigerant evaporator 6, and each is connected by a refrigerant pipe 10.

The refrigerant compressor 2 is driven by a traveling engine 12 of the vehicle via an electromagnetic clutch 11, compresses the drawn gas refrigerant to a high temperature and a high pressure, and discharges it.

The refrigerant condenser 3 condenses and liquefies the refrigerant discharged from the refrigerant compressor 2 by exchanging heat with air.

The receiver 4 temporarily stores the refrigerant guided from the refrigerant condenser 3 and discharges the refrigerant to the expansion valve 5 according to the load.

The expansion valve 5 adiabatically expands the refrigerant supplied from the receiver 4 and discharges the refrigerant to the refrigerant evaporator 6.

The refrigerant evaporator 6 evaporates the supplied liquid refrigerant by exchanging heat with the air and cools the air. The evaporated gas refrigerant is sucked into the refrigerant compressor 2.

The first gas-liquid separator 7 is provided in the refrigerant passage 13 during the heat exchange of the refrigerant condenser 3, and separates the condensed and liquefied liquid refrigerant from the gas refrigerant before condensation to extract the liquid refrigerant. Things.

The second gas-liquid separator 8 is provided in the refrigerant passage 14 during the heat exchange of the refrigerant evaporator 6, and separates the evaporated gas refrigerant and the unevaporated liquid refrigerant to extract the gas refrigerant. is there.

As shown in FIG. 2, the first gas-liquid separator 7 is composed of a large-diameter outer tube 15 and a small-diameter inner tube 16, and has a double-tube structure. It is crimped on the outer periphery of the tube 16.

In the first gas-liquid separator 7, the other end 15b of the outer peripheral tube 15 serving as the refrigerant inlet is connected to the lower end of the upstream refrigerant passage 13a of the refrigerant condenser 3, and the inner periphery serving as the extraction outlet of the separated gas refrigerant is provided. One end 16a of the tube 16 is connected to the upper end of a downstream refrigerant passage 13b (a downstream portion of the refrigerant condenser of the present invention) of the refrigerant condenser 3. The other end 16b of the inner peripheral tube 16 is open at the center of the outer peripheral tube 15 in the flow direction of the refrigerant.

An extraction outlet 15c for extracting the separated liquid refrigerant is provided at one end of the outer peripheral tube 15, and a refrigerant pipe 10a
Is connected to the receiver 4 via the.

On the other hand, the second gas-liquid separator 8 shown in FIG. 3 is composed of a large-diameter outer tube 17 and a small-diameter inner tube 18 like the first gas-liquid separator 7, and has a double tube structure. One end 17a of the outer peripheral tube 17 is caulked to the outer peripheral portion of the inner peripheral tube 18.

In the second gas-liquid separator 8, the other end 17b of the outer peripheral tube 17 serving as the inlet of the refrigerant is connected to the lower end of the upstream refrigerant passage 14a of the refrigerant evaporator 6, and the inner periphery serving as the extraction outlet of the separated gas refrigerant is provided. One end 18a of the tube 18 is connected to the refrigerant compressor 2 via the refrigerant pipe 10b. The other end 18 of the inner peripheral tube 18
“b” is open toward the flow direction of the refrigerant at the center in the outer peripheral tube 17.

An extraction outlet 17c for extracting the separated liquid refrigerant is provided on one end side of the outer peripheral tube 17, and is provided in a downstream refrigerant passage 14b of the refrigerant evaporator 6 (a downstream portion of the refrigerant evaporator of the present invention). Connected to the upper end.

The first gas-liquid separator 7 and the second gas-liquid separator 8 described above include:
The gas-liquid two-phase refrigerant flowing through the refrigerant passages 13 and 14 is provided at a location where the refrigerant flows into an annular flow (substantially at the center between the upstream and downstream of the refrigerant passages 13 and 14).

Therefore, the refrigerant guided to the first gas-liquid separator 7 is such that the liquid refrigerant flows near the outer periphery in the outer tube 15 and the gas refrigerant flows in the central portion. Liquid refrigerant is extracted from 15c, and gas refrigerant is extracted through the inner peripheral tube 16. The liquid refrigerant extracted from the extraction outlet 15c is supplied to the receiver 4 through the refrigerant pipe 10a connected to the extraction outlet 15c, and the gas refrigerant extracted through the inner peripheral tube 16 is connected to the inner peripheral tube 16. Into the downstream refrigerant passage 13b of the refrigerant condenser 3 to be cooled.

Further, the refrigerant guided to the second gas-liquid separator 8 is such that the liquid refrigerant flows near the outer periphery in the outer tube 17 and the gas refrigerant flows in the central portion, so that the extraction outlet provided at one end of the outer tube 17 is provided. Liquid refrigerant is extracted from 17c, and gas refrigerant is extracted through the inner peripheral tube 18. The gas refrigerant extracted through the inner peripheral tube 18 is sucked into the refrigerant compressor 2 through the refrigerant pipe 10b connected to the inner peripheral tube 18, and the liquid refrigerant extracted from the extraction outlet 17c is extracted by the extraction outlet 17c. Flows into the downstream side refrigerant passage 14b of the refrigerant evaporator 6 connected to the refrigerant evaporator 6.

The refrigerant heat exchanger 9 exchanges heat between the liquid refrigerant extracted by the first gas-liquid separator 7 and guided to the receiver 4 and the gas refrigerant extracted by the second gas-liquid separator 8 and guided to the refrigerant compressor 2. For example, as shown in FIG.
The refrigerant pipe 10b is configured to spirally turn around the outer circumference of 10a.

This refrigerant heat exchanger 9 is the first gas-liquid separator 7 of the present embodiment.
In addition, since the second gas-liquid separator 8 cannot completely separate the liquid refrigerant and the gas refrigerant, heat exchange is performed between the liquid refrigerant extracted from the refrigerant condenser 3 and the gas refrigerant extracted from the refrigerant evaporator 6. Thus, the liquid refrigerant containing the superheated gas extracted from the refrigerant condenser 3 is completely liquefied, and the gas refrigerant containing the unevaporated liquid refrigerant extracted from the refrigerant evaporator 6 is completely gasified.

 Next, the operation of the refrigeration cycle 1 will be described.

The refrigerant compressor 2 is driven by receiving the power of the engine 12 when the electromagnetic clutch 11 is energized.

The refrigerant compressor 2 compresses the sucked gas refrigerant to a high temperature and a high pressure, discharges the compressed gas refrigerant, and supplies the refrigerant to the refrigerant condenser 3.

In the refrigerant condenser 3, the supplied gas refrigerant is supplied to the refrigerant passage 13.
When it flows through it, it exchanges heat with the air outside the cabin and condenses and liquefies.

At this time, when the gas-liquid two-phase refrigerant flowing through the refrigerant passage 13 while being liquefied reaches the first gas-liquid separator 7, the refrigerant flows in an annular flow, since the refrigerant flows in an annular flow. The liquid refrigerant is extracted through the refrigerant pipe 10a from the extraction outlet 15c provided in the outer peripheral tube 15 of the first gas-liquid separator 7, and heat-exchanges with the gas refrigerant extracted from the refrigerant evaporator 6 in the refrigerant heat exchanger 9. After that, it is guided to the receiver 4.

On the other hand, the gas refrigerant flowing in the center of the refrigerant passage 13 is the first refrigerant.
Flow through the inner tube 16 of the gas-liquid separator 7
Of the refrigerant condenser 3 from the one end 16a.

As a result, the liquid refrigerant is removed downstream of the first gas-liquid separator 7 and becomes only the gas refrigerant.
The heat exchange efficiency on the downstream side is improved.

The refrigerant condensed and liquefied in the refrigerant condenser 3 is guided to the receiver 4 and then supplied to the expansion valve 5 according to the load.

The refrigerant supplied to the expansion valve 5 is adiabatically expanded and discharged to the refrigerant evaporator 6.

In the refrigerant evaporator 6, the liquid refrigerant flowing through the refrigerant passage 14 evaporates by taking latent heat from the air blown into the vehicle interior, and is sucked into the refrigerant compressor 2 as a gas refrigerant.

At this time, when the gas-liquid two-phase refrigerant flowing through the refrigerant passage 14 while being gasified reaches the second gas-liquid separator 8, the flow of the refrigerant is an annular flow. The flowing mist refrigerant passes through an extraction outlet 17 c provided in the outer peripheral tube 17 of the second gas-liquid separator 8 and is connected to the refrigerant passage 1 on the downstream side of the refrigerant evaporator 6.
Supplied to 4b.

On the other hand, the gas refrigerant flowing in the central portion of the refrigerant passage 14 is the second refrigerant.
Flow through the inner tube 18 of the gas-liquid separator 8
The refrigerant is extracted from one end 18a through the refrigerant pipe 10b, exchanges heat with the liquid refrigerant extracted from the refrigerant condenser 3 in the refrigerant heat exchanger 9, and is then sucked into the refrigerant compressor 2.

As a result, the gas refrigerant is removed downstream of the second gas-liquid separator 8 so that only the atomized refrigerant is present, so that the heat exchange efficiency downstream of the refrigerant evaporator 6 is improved.

Further, in the operation of the refrigeration cycle 1, the refrigerant heat exchanger 9 causes heat exchange between the liquid refrigerant extracted from the refrigerant condenser 3 and the gas refrigerant extracted from the refrigerant evaporator 6.
The superheated gas contained in the liquid refrigerant is condensed and liquefied, and the unevaporated liquid refrigerant contained in the gas refrigerant is vaporized and gasified.

As a result, the liquid refrigerant containing the superheated gas extracted from the refrigerant condenser 3 by the first gas-liquid separator 7 is completely liquefied and guided to the receiver 4, and the second gas-liquid separator 8 outputs the liquid refrigerant from the refrigerant evaporator 6. The extracted gas refrigerant including the unevaporated liquid refrigerant is completely gasified and guided to the refrigerant compressor 2.

Therefore, it is possible to prevent the superheated gas from flowing into the receiver 4 and re-evaporating the liquid refrigerant into the receiver 4, and the liquid refrigerant is sucked into the refrigerant compressor 2 to damage the refrigerant compressor 2 due to the liquid compression. Can be prevented.

Further, since the liquid refrigerant extracted from the refrigerant condenser 3 and the gas refrigerant extracted from the refrigerant evaporator 6 can be completely liquefied and gasified, a decrease in the efficiency of the refrigeration cycle 1 can be prevented.

 FIG. 4 shows a second embodiment of the present invention.

In the present embodiment, the refrigeration cycle 1 of the present invention employs an accumulator cycle.

Accordingly, the refrigeration cycle 1 of the present embodiment includes the refrigerant compressor 2, the refrigerant condenser 3, the refrigerant evaporator 6, the first gas-liquid separator 7, the second gas-liquid separator 8, and the refrigerant compressor 2 shown in the first embodiment. In addition to the refrigerant heat exchanger 9, a capillary tube 19, which is a decompression device of the present invention, is provided upstream of the refrigerant evaporator 6, and an accumulator 20 is provided upstream of the refrigerant compressor 2.

 FIG. 5 shows a third embodiment of the present invention.

In the present embodiment, the refrigerant heat exchanger 9 is arranged upstream of the refrigerant compressor 2, and the refrigerant extracted from the refrigerant evaporator 6 by the second gas-liquid separator 8 joins with the gas refrigerant evaporated by the refrigerant evaporator 6. After that, it is guided to the refrigerant heat exchanger 9.

(Modifications) The case where the refrigeration cycle 1 of the present invention is applied to an air conditioner for a vehicle has been exemplified. However, air conditioners for home use, commercial use, industrial use, air conditioners for railways and ships, refrigeration units,
It may be applied to a refrigerating device or the like.

In addition, as the refrigerant heat exchanger 9, the refrigerant heat exchanger 9 is configured such that the refrigerant pipe 10b spirally turns around the outer circumference of the refrigerant pipe 10a, but the refrigerant pipe 10a turns spirally around the outer circumference of the refrigerant pipe 10b. The refrigerant heat exchanger may have a double-tube structure, in which a small-diameter heat exchange passage is provided inside a large-diameter heat exchange passage.

[Brief description of the drawings]

FIGS. 1 to 3 show a first embodiment of the present invention. FIG. 1 is a refrigerant circuit diagram of a refrigeration cycle of the present invention.
FIG. 3 is a sectional view of a first gas-liquid separator, FIG. 3 is a sectional view of a second gas-liquid separator, FIG. 4 is a refrigerant circuit diagram of a refrigeration cycle showing a second embodiment of the present invention, and FIG. FIG. 7 is a refrigerant circuit diagram of a refrigeration cycle showing a third embodiment of the present invention. In the drawing, 1 ... refrigeration cycle, 2 ... refrigerant compressor 3 ... refrigerant condenser, 5 ... expansion valve (decompression device) 6 ... refrigerant evaporator, 7 ... first gas-liquid separator 8 ... 2b gas-liquid separator 13b ... downstream refrigerant passage (downstream part of refrigerant condenser) 14b ... downstream refrigerant passage (downstream part of refrigerant evaporator) 19 ... capillary tube (pressure reducing device)

Claims (1)

(57) [Claims] (A) a refrigerant compressor for compressing and discharging a sucked gas refrigerant; (b) a refrigerant condenser for condensing and liquefying a high-pressure refrigerant discharged from the refrigerant compressor; A decompression device for adiabatically expanding the refrigerant supplied from the refrigerant condenser; (d) a refrigerant evaporator for evaporating the refrigerant adiabatically expanded by the decompression device; and (e) a heat exchanger provided between the refrigerant condensers. Separating the gas refrigerant before condensation and the liquid refrigerant after condensation, extracting the separated liquid refrigerant, supplying the separated liquid refrigerant to the pressure reducing device, and allowing the separated gas refrigerant to flow into a downstream portion of the refrigerant condenser. (F) a gas-liquid separator provided between heat exchangers of the refrigerant evaporator, for separating liquid refrigerant before evaporation and gas refrigerant after evaporation, extracting the separated gas refrigerant, The liquid refrigerant supplied to the compressor and separated is supplied to the refrigerant evaporator. (G) a liquid refrigerant extracted by the first gas-liquid separator and guided to the pressure reducing device, and a refrigerant extracted by the second gas-liquid separator and extracted by the second gas-liquid separator. A refrigerant heat exchanger for exchanging heat with a gas refrigerant guided to the compressor.