JP2002349978A - Ejector cycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply sufficient amount of lubrication oil to a compressor, even when an ejector cycle continues to be operated continuously for a long time. SOLUTION: An oil return piping 510, which returns the lubrication oil separated from a refrigerant inside a gas-liquid separator 500 to the suction side of the compressor 100, is installed. Herewith, since sufficient amount of lubrication oil can be supplied to the compressor 100, even when the ejector cycle continues to be operated continuously over a long time, the compressor 100 can be prevented from seizing due to shortage of the lubrication oil. Also, since a liquid refrigerant, which must be normally sucked into the side of an evaporator 300, can be prevented from being sucked into the side of the compressor 100 and the amount of the lubrication oil sucked into the evaporator 300 can be reduced, resulting reduction in the amount of the liquid refrigerant sucked into the evaporator 300 is prevented and lowering of the refrigeration capacity (endothermic amount) generated in the evaporator 300 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ejector cycle.

[0002]

2. Description of the Related Art An ejector cycle is described in, for example, Japanese Patent Application Laid-Open No. 6-11197, in which a refrigerant is decompressed and expanded to suck a vapor-phase refrigerant evaporated in an evaporator, and expansion energy (normal vapor compression The refrigeration cycle is a refrigeration cycle having an ejector that converts kinetic energy (discarded by a decompressor such as an expansion valve) into pressure energy to increase the suction pressure of a compressor.

[0003]

Incidentally, not only in the ejector cycle, but in a refrigeration cycle in general, lubrication in a compressor is performed by mixing lubricating oil (refrigeration oil) in a refrigerant.

On the other hand, since the refrigerant evaporates in the evaporator,
Lubricating oil and refrigerant are easily separated. For this reason, in the invention described in the above publication, if the ejector cycle is continuously operated for a long time, lubricating oil is accumulated in the evaporator side,
Due to the lubricating oil adhering to the inner surface of the evaporator, as shown in FIG. 27, the heat exchange capacity (refrigeration capacity) of the evaporator is reduced, and the amount of lubricating oil returning to the compressor is reduced. Lubrication may not be possible.

In view of the above, an object of the present invention is to supply a sufficient amount of lubricating oil to a compressor even when an ejector cycle is continuously operated for a long time.

[0006]

According to the present invention, in order to achieve the above object, according to the first aspect of the present invention, a compressor (100) for sucking and compressing a refrigerant and a compressor discharged from the compressor (100) are provided. A radiator (200) for radiating heat of the refrigerant, and an evaporator (30) for exhibiting an endothermic effect by evaporating the refrigerant.
0), a nozzle (410) for converting the pressure energy of the high-pressure refrigerant flowing out of the radiator (200) into velocity energy to decompress and expand the refrigerant, and a high-speed refrigerant flow jetted from the nozzle (410). A mixing unit (420) for sucking the vapor-phase refrigerant evaporated in (300), and converting the velocity energy into pressure energy while mixing the refrigerant injected from the nozzle (410) with the refrigerant sucked from the evaporator (300). (400) having a diffuser (430) for increasing the pressure of the refrigerant, a gas-liquid separator (500) for storing the refrigerant by separating the refrigerant into a gaseous refrigerant and a liquid-phase refrigerant, and a lubrication device separated from the refrigerant. Compress oil (1
00), an oil return circuit (510) for returning to the suction side.

[0007] Thus, even when the ejector cycle is continuously operated for a long time, a sufficient amount of lubricating oil can be supplied to the compressor (100). The compressor (100) can be prevented from seizing due to insufficient lubricating oil while preventing a large amount of lubricating oil from accumulating in the compressor.

Here, "lubricating oil separated from refrigerant" does not mean 100% lubricating oil, but a large amount of lubricating oil in a mixed fluid of lubricating oil and refrigerant (the concentration of lubricating oil is high). It means mixed fluid.

In addition, the liquid refrigerant, which should be drawn into the evaporator (300), can be prevented from being drawn into the compressor (100).
It is possible to prevent the amount of liquid refrigerant sucked into the tank from decreasing. As a result, it is possible to prevent the refrigerating capacity (heat absorption amount) generated in the evaporator (300) from being reduced.

[0010] The oil return circuit (510) is connected to the gas-liquid separator (500) as in the second aspect of the present invention, and supplies the lubricating oil separated from the refrigerant to the compressor (100).
It is desirable to return to the suction side.

The oil return circuit (510) is configured to return lubricating oil accumulated in the evaporator (300) to the suction side of the compressor (100), as in the third aspect of the present invention. Is also good.

Since the fluid flowing through the oil return circuit (510) is not 100% lubricating oil as described above, a liquid refrigerant is mixed in the fluid.

Therefore, the invention according to claim 4 is characterized in that a heating means (520, 530, 540) for heating the fluid flowing in the oil return circuit (510) is provided.

Thus, the liquid refrigerant in the fluid flowing through the oil return circuit (510) can be vaporized (evaporated), so that the liquid refrigerant can be reliably sucked into the compressor (100). Can be prevented.

Therefore, the compression work of the compressor (100) can be prevented from being unnecessarily increased, so that the coefficient of performance of the ejector cycle can be prevented from being lowered.

According to the invention described in claim 5, the evaporator (30)
0) and the oil return circuit (51) before the heat is absorbed.
0) heat exchanger (53) for exchanging heat with the fluid flowing in
0).

Thus, the liquid refrigerant in the fluid flowing through the oil return circuit (510) can be vaporized (evaporated) as in the fourth aspect of the invention, so that the coefficient of performance of the ejector cycle is reduced. It can be prevented from lowering.

In the invention according to claim 6, the compressor (10
High pressure refrigerant discharged from 0) and oil return circuit (510)
A heat exchanger (540) for exchanging heat with a fluid flowing through the inside is provided.

As a result, the liquid refrigerant in the fluid flowing through the oil return circuit (510) can be vaporized (evaporated) in the same manner as in the fourth aspect of the invention, so that the coefficient of performance of the ejector cycle is reduced. It can be prevented from lowering.

It is to be noted that the gas-liquid separator (500) side of the oil return circuit (510) is,
In the gas-liquid separator (500), the gas-liquid separator (500) is connected to a portion where the lubricating oil concentration is higher than the refrigerant concentration.

According to an eighth aspect of the present invention, there is provided the gas-liquid separator for an ejector cycle according to the first aspect, wherein a lubricating oil having a density greater than a density of the liquid-phase refrigerant is used. It has a tank part (501) for storing, in the tank part (501), a liquid-phase refrigerant outlet (504) for supplying a liquid-phase refrigerant to the evaporator (300) side, and a gas-phase refrigerant for the compressor (100). The gas-phase refrigerant outlet (50
3) and an oil return port (505) to which an oil return circuit (510) is connected. Further, an ejector (40) is provided above the liquid-phase refrigerant outlet (504).
0), the inflow suppressing member (5) for suppressing the refrigerant flowing directly into the liquid-phase refrigerant outlet (504).
06) is provided.

In a gas-liquid separator not provided with the inflow suppressing member (506), the dynamic pressure (force) of the refrigerant flowing from the ejector (400) into the tank (501).
Accordingly, the refrigerant flowing into the tank (501) flows into the liquid refrigerant outlet (504) as it is.

At this time, since the refrigerant flowing out of the ejector (400) is mixed in an immiscible state in which the refrigerant and the lubricating oil are not dissolved, the refrigerant in the immiscible state (having a high concentration of the lubricating oil) When the refrigerant flows into the liquid refrigerant outlet (504), the liquid refrigerant having a high lubricating oil concentration flows into the evaporator (300), and the refrigerating capacity (heat exchange capacity) generated in the evaporator (300). Will decrease.

On the other hand, in the present embodiment, the refrigerant that has flowed into the tank portion (501) by the inflow suppressing member (506) can be prevented from flowing into the liquid refrigerant outflow port (504) as it is, so that evaporation can be prevented. The liquid refrigerant having a high lubricating oil concentration can be prevented from flowing into the evaporator (300), and the refrigerating capacity (heat exchange capacity) generated in the evaporator (300) can be prevented from being reduced.

It is desirable that the inflow suppressing member (506) is formed in an umbrella shape such that the upper side is convex, as in the ninth aspect of the present invention.

Further, according to the invention as set forth in claim 10,
It is desirable to provide a through hole (506a) at the upper end of the inflow suppressing member (506).

According to the eleventh aspect of the present invention, there is provided the gas-liquid separator for an ejector cycle according to the first aspect, wherein a lubricating oil having a density larger than a density of the liquid-phase refrigerant is used. A liquid-phase refrigerant outflow pipe (504) for supplying the liquid-phase refrigerant in the tank (501) to the evaporator (300) side; Gas phase refrigerant outflow pipe (50) for supplying the gas phase refrigerant in the section (501) to the suction side of the compressor (100).
3) and an oil return port (505) to which an oil return circuit (510) is connected, and a refrigerant suction port opened in the tank portion (501) of the liquid-phase refrigerant outflow pipe (504). (504a) is characterized in that it is open horizontally or upward.

[0028] Thus, in the vicinity of the refrigerant suction port (504a), from the upper side to the lower side (the refrigerant suction port (504a)).
Side), the lubricating oil is entrained in the flow of the liquid-phase refrigerant and the flow of the liquid-phase refrigerant outflow pipe (50).
4) It is possible to prevent the lubricating oil from flowing in.

According to the twelfth aspect of the present invention,
The refrigerant suction port (504) of the liquid-phase refrigerant outflow pipe (504)
The refrigerant suction port (504a) may be configured to open horizontally or upward by bending the side a) in the tank portion (501).

Further, according to the invention of claim 13,
If the refrigerant suction port (504a) is provided on the side surface of the tubular pipe portion (504b) of the liquid-phase refrigerant outflow pipe (504), the liquid-phase refrigerant outflow pipe (504) is bent as compared with the case where the liquid-phase refrigerant outflow pipe (504) is bent. Since the space occupied by the outflow pipe (504) in the tank (501) is reduced, the size of the gas-liquid separator can be reduced.

Further, according to the invention of claim 14,
The liquid-phase refrigerant outflow pipe (504) is a tubular pipe part (504).
b) and a suction port forming member (504c) connected to the pipe section (504b) to form a refrigerant suction port (504a).

According to the fifteenth aspect of the present invention, if an oil discharge port (504d) opened downward is provided below the suction port forming member (504c), the suction port forming member (504c) can be provided. Since the lubricating oil accumulated inside can be discharged from the oil discharge port (504d), it is possible to reliably prevent a large amount of lubricating oil from being sucked into the liquid refrigerant outflow pipe (504) together with the liquid refrigerant.

Further, according to the invention of claim 16,
Foreign matter is present in the liquid refrigerant outflow pipe (5) on the refrigerant suction port (504a) side.
04) to prevent the filter means (5) from being inhaled.
04e) is desirably provided.

By the way, the reference numerals in parentheses of the above means are examples showing the correspondence with specific means described in the embodiments described later.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment)
The ejector cycle according to the present invention is applied to a vehicle air conditioner using carbon dioxide as a refrigerant, and FIG. 1 is a schematic view of an ejector cycle according to the present embodiment.

Numeral 100 denotes a compressor that draws a driving force from a driving source (not shown) such as a running engine to suck and compress the refrigerant, and 200 heat-exchanges the refrigerant discharged from the compressor 100 with outdoor air. Radiator (gas cooler) that cools the refrigerant
It is.

Reference numeral 300 denotes an evaporator which exhibits a refrigerating ability by absorbing heat from the air blown into the room and evaporating the liquid-phase refrigerant, and 400 denotes an evaporator 300 which decompresses and expands the refrigerant flowing out of the radiator 200 and expands the refrigerant. This is an ejector that sucks the evaporated gas-phase refrigerant and converts expansion energy into pressure energy to increase the suction pressure of the compressor 100.

As shown in FIG. 2, the ejector 400 converts the pressure energy (pressure head) of the high-pressure refrigerant flowing out of the radiator 200 into velocity energy (velocity head).
A nozzle 410 for converting the pressure into a refrigerant and decompressing and expanding the refrigerant, a mixing section 420 for sucking the vapor-phase refrigerant evaporated in the evaporator 300 by a high-speed refrigerant flow (jet flow) jetted from the nozzle 410, and jetting from the nozzle 410 It is composed of a diffuser 430 or the like that converts velocity energy into pressure energy while increasing the pressure of the refrigerant while mixing the refrigerant and the refrigerant sucked from the evaporator 300.

In FIG. 1, reference numeral 500 denotes an ejector 400.
Is a gas-liquid separator that stores the refrigerant by separating the inflowing refrigerant into a gas-phase refrigerant and a liquid-phase refrigerant, and the separated gas-phase refrigerant is sucked into the compressor 100, The separated liquid-phase refrigerant is sucked into the evaporator 300 side.

The lubricating oil separated from the refrigerant in the gas-liquid separator 500 is supplied to the compressor 100.
Oil return pipe (oil return circuit) 51 to return to the suction side of oil
0, and in this embodiment, a mineral oil such as polyglycol (PAG) having a liquid density higher than the liquid density of the refrigerant is used as the lubricating oil. It is connected to the lowest part of the vessel 500.

The refrigerant passage connecting the gas-liquid separator 500 and the evaporator 300 is used to reduce the pressure of the refrigerant sucked into the evaporator 300 and reduce the pressure in the evaporator 300 (evaporation pressure). Like a capillary tube or fixed aperture,
It is set so that a predetermined pressure loss is generated by the circulation of the refrigerant.

FIG. 4 is a ph diagram showing the operation of the ejector cycle according to the present embodiment. The numbers shown in FIG. 4 indicate the state of the refrigerant at the positions indicated by the numbers in FIG.

Then, the suction pressure increase ΔP of the compressor 100
Although the absolute value changes depending on the efficiency in the mixing unit 420 and the diffuser 430, the refrigerant inlet of the nozzle 410 (point 6 in FIG. 4) and the refrigerant inlet of the diffuser 430 (point 3 in FIG. 4). Becomes larger as the specific enthalpy difference (adiabatic heat drop) becomes larger.

Next, the features of this embodiment will be described.

In this embodiment, since the oil return pipe 510 for returning the lubricating oil separated from the refrigerant in the gas-liquid separator 500 to the suction side of the compressor 100 is provided, the ejector cycle can be continuously performed for a long time. Even when the operation is continued, a sufficient amount of lubricating oil can be supplied to the compressor 100.

Therefore, it is possible to prevent the compressor 100 from burning due to insufficient lubricating oil, so that the reliability (durability) of the ejector cycle can be improved.

Incidentally, since the amount of lubricating oil present in the ejector cycle is constant, the fact that a sufficient amount of lubricating oil returns to the compressor 100 means that the amount of lubricating oil retained in the evaporator 300 is small. Means decrease. Therefore, it is possible to prevent the heat exchange capacity (refrigeration capacity) of the evaporator 300 from being reduced.

Further, since the oil return pipe 510 is connected to the lowermost part of the gas-liquid separator 500, in the present embodiment using a lubricating oil having a liquid density higher than the liquid density of the refrigerant, Since the oil return pipe 510 is connected to a portion where the lubricating oil concentration is higher than the refrigerant concentration, the lubricating oil can be reliably returned to the compressor 100.

In addition, since the liquid refrigerant that should be drawn into the evaporator 300 can be prevented from being drawn into the compressor 100, the amount of the liquid refrigerant drawn into the evaporator 300 is reduced. Can be prevented. As a result, it is possible to prevent the refrigerating capacity (heat absorption amount) generated in the evaporator 300 from being reduced.

As described above, according to the present embodiment,
While preventing the seizure of the compressor 100 and improving the reliability (durability) of the ejector cycle, the evaporator 30
It is possible to prevent the refrigeration capacity (heat absorption amount) generated at 0 from being reduced.

(Second Embodiment) In the first embodiment, the lubricating oil separated from the refrigerant in the gas-liquid separator 500 is supplied to the compressor 1
In this embodiment, as shown in FIG. 5, the oil return pipe 510 is connected to the refrigerant outlet side of the evaporator 300 to separate the refrigerant from the refrigerant in the evaporator 300 (evaporation). Lubricating oil collected in the compressor 300
It is configured to return to the suction side of 00.

This utilizes the fact that a relatively large amount of lubricating oil accumulates on the refrigerant outlet side of the evaporator 300 since the vaporized refrigerant and the lubricating oil in the liquid phase are relatively easily separated. .

Although the oil return pipe 510 is connected to the refrigerant outlet side of the evaporator 300 in the present embodiment, the oil return pipe 510 is connected to the refrigerant inlet of the evaporator 300 or between the refrigerant inlet and the refrigerant outlet (in the evaporator 300). The oil return pipe 510 may be connected.

(Third Embodiment) Since the fluid flowing through the oil return pipe 510 is not a 100% lubricating oil but a mixed fluid with a liquid refrigerant containing a large amount of lubricating oil, the compressor 100 If the fluid is sucked as it is, the compressor 100 performs liquid compression, and the compression work of the compressor 100 may be excessively increased.

Therefore, in this embodiment, as shown in FIG. 6, an electric heater (heating means) for heating a fluid (a refrigerant containing a large amount of lubricating oil) flowing in the oil return pipe 510.
520 are provided.

Thus, the liquid refrigerant in the fluid flowing through the oil return pipe 510 can be vaporized (evaporated), so that the liquid refrigerant can be reliably prevented from being sucked into the compressor 100. Therefore, it is possible to prevent the compression work of the compressor 100 from unnecessarily increasing.
It is possible to prevent the coefficient of performance of the ejector cycle from decreasing.

(Fourth Embodiment) In the third embodiment, the heating means for heating the fluid flowing through the oil return pipe 510 by the electric heater 520 is configured.
As shown in FIG. 7, a heat exchanger 530 that exchanges heat between air (fluid) before being absorbed by the evaporator 300 and fluid flowing through the oil return pipe 510 on the upstream side of the air flow of the evaporator 300. This constitutes a heating means for heating the fluid flowing through the oil return pipe 510.

(Fifth Embodiment) In the third embodiment, the heating means for heating the fluid flowing through the oil return pipe 510 by the electric heater 520 is formed.
As shown in FIG. 8, the high-pressure refrigerant (the refrigerant on the outlet side of the radiator 200 in the present embodiment) discharged from the compressor 100 and the fluid flowing through the oil return pipe 510 exchange heat with the heat exchanger 540. This constitutes a heating means for heating the fluid flowing through the return pipe 510.

(Sixth Embodiment) In the above embodiment, carbon dioxide was used as the refrigerant. However, this embodiment uses Freon (R404a) as the refrigerant and mineral oil such as polyglycol (PAG) as the lubricating oil. Is used.

In this embodiment, since the liquid density of the lubricating oil in the gas-liquid separator 500 is lower than that of the liquid refrigerant, the lubricating oil is opened in the gas-liquid separator 500 and the oil return pipe 51 is opened.
The oil suction port 511 communicating with 0 is located at a predetermined depth with respect to the liquid level.

More specifically, as shown in FIGS. 9 and 10, a pipe portion in the gas-liquid separator 500 provided with an oil suction port 511 (hereinafter, this portion is referred to as a movable pipe portion) can be displaced. The movable pipe portion 512 is connected to a float 513 floating on the liquid surface.

Thus, even if the liquid level fluctuates, the oil suction port 511 operates so as to always be located at a predetermined depth based on the liquid level.

FIG. 9 shows a movable pipe section 512 (512) connected to a float 513 on a fixed-side pipe section 512a.
b) is a telescopic type in which the movable piping section 512 is formed by inserting the movable piping section 512. FIG.
12 is a flexible type made of a deformable material such as rubber.

(Seventh Embodiment) This embodiment relates to a gas-liquid separator 500 for an ejector cycle according to the first embodiment, and FIG. 11 is a schematic sectional view of a gas-liquid separator according to the present embodiment. It is.

In FIG. 11, reference numeral 501 denotes a tank portion made of a metal (in this embodiment, an aluminum alloy) for storing a refrigerant, into which the gas-liquid two-layer refrigerant flowing out of the ejector 400 flows. Incoming pipe 50
2. A gas-phase refrigerant outlet pipe (gas-phase refrigerant outlet) 503 for supplying the separated gas-phase refrigerant to the suction side of the compressor 100, and a liquid-phase refrigerant outlet pipe (for supplying the separated liquid-phase refrigerant to the evaporator 300 side) A liquid refrigerant outlet 504 and an oil return port 505 to which an oil return pipe 510 is connected are provided.

Then, above the liquid-phase refrigerant outflow pipe 504 and above the interface (oil surface) between the lubricating oil and the liquid-phase refrigerant, the inflow pipe 502 flows into the tank 501. An umbrella-shaped (cone-shaped) metal (in the present embodiment, an aluminum alloy) inflow suppression plate (inflow suppression) formed to prevent the gas-liquid two-layer refrigerant from directly flowing into the liquid-phase refrigerant outflow pipe 504. Member 506 is provided.

As shown in FIG. 12, the inflow suppression plate 506 is formed with a through hole (gas vent hole) 506a penetrating the inflow suppression plate 506 at its upper end (top). The inflow prevention plate 506 is connected to the liquid-phase refrigerant outflow pipe 50.
4 is welded to a stay 506b for fixing to the front end side.

Next, the features (effects) of this embodiment will be described.

FIG. 13A shows a gas-liquid separator without the inflow suppressing plate 506, and FIG. 13B shows a gas-liquid separator 500 according to the present embodiment.
Among them, the region A indicates a layer having a lubricating oil concentration of about 0%, and the region B indicates a layer having a lubricating oil concentration of about 45% or more.

As shown in FIG. 13, in the gas-liquid separator not provided with the inflow suppressing plate 506, the dynamic pressure (force) of the refrigerant flowing into the tank 501 from the inflow pipe 502 causes the tank to flow from the inflow pipe 502 to the tank. The refrigerant flowing into the portion 501 flows into the liquid refrigerant outflow pipe 504 as it is.

At this time, the refrigerant flowing out of the ejector 400 (immediately after flowing out of the inflow pipe 502) is mixed in an immiscible state in which the refrigerant and the lubricating oil are not melted. When a refrigerant (a refrigerant having a high lubricating oil concentration) flows into the liquid refrigerant outflow pipe 504, the evaporator 3
A liquid refrigerant having a high concentration of lubricating oil flows into 00,
The refrigerating capacity (heat exchange capacity) generated in the evaporator 300 is reduced.

On the other hand, in the present embodiment, the refrigerant flowing from the inflow pipe 502 into the tank 501 can be prevented from flowing into the liquid refrigerant outflow pipe 504 as it is by the inflow suppression plate 506, and thus the evaporator 300 can be prevented. The liquid refrigerant having a high lubricating oil concentration can be prevented from flowing into the evaporator 300, and the refrigeration capacity (heat exchange capacity) generated in the evaporator 300 can be prevented from being reduced.

FIG. 14 shows the ratio of the lubricating oil in the refrigerant flowing into the evaporator 300 (evaporator inlet oil rate) and the lubricating oil in the refrigerant flowing into the compressor 100 using the presence or absence of the inflow suppressing plate 506 as a parameter. Is a result obtained by a test with respect to the ratio (compressor suction oil rate).
It can be seen that the inflow to the side is suppressed.

By the way, the portion below the inflow suppression plate 506 is hardly affected by the dynamic pressure (power) of the refrigerant flowing into the tank portion 501 from the inflow pipe 502, and the flow of the liquid-phase refrigerant is gentle and less turbulent. In the present embodiment, the refrigerant inlet 504a (see FIG. 11) of the liquid refrigerant outflow pipe 504 that opens in the tank 501 is connected to the inflow suppression plate 50.
6, the liquid refrigerant outflow pipe 5
It is possible to prevent the flow of the liquid-phase refrigerant flowing into the liquid 04 from being disturbed, and to reduce the occurrence of unnecessary pressure loss due to the disturbance of the flow.

Further, since the refrigerant inlet 504a of the liquid refrigerant outflow pipe 504 is located at the upper end side of the conical (umbrella) inflow suppression plate 506, the liquid refrigerant having a low lubricating oil concentration can be reliably sucked. Can be.

Further, since the through hole 506 a penetrating the inflow suppression plate 506 is formed at the upper end (top) of the inflow suppression plate 506, the gas-phase refrigerant generated below the inflow suppression plate 506 is supplied to the tank 501. It can flow to the upper gas phase refrigerant layer.

(Eighth Embodiment) This embodiment is different from FIG.
As shown in FIG. 16, the refrigerant inlet (refrigerant inlet) 504a of the liquid refrigerant outflow pipe (liquid phase refrigerant outflow pipe) 504 is located on the upper side in a portion where a large amount of liquid phase refrigerant exists (between the liquid surface and the oil surface). It is designed to open toward.

FIG. 15 shows an example in which the liquid refrigerant outflow pipe 504 is inserted into the tank 501 from above the tank 501 and the refrigerant inlet 504a is bent in a U-shape.
FIG. 16 shows an example in which the liquid refrigerant outflow pipe 504 is inserted into the tank portion 501 from the side of the tank portion 501 and the refrigerant inlet 504a side is bent in an L (J) shape.

In this embodiment, the oil return port 5
05 is provided at the bottom of a gas-phase refrigerant outflow pipe (gas-phase refrigerant outflow pipe) 503 bent in a U-shape so that the lower side is convex. In the present embodiment, the gas-liquid separator 500 The separated lubricating oil is mixed with the gas phase refrigerant in the gas phase refrigerant outflow pipe 503 and supplied to the compressor 100 together with the gas phase refrigerant.

Next, the features of this embodiment will be described.

FIG. 17 is a characteristic diagram showing the compatibility between the lubricating oil (PAG) and the refrigerant (carbon dioxide).
In FIG. 18, the pressure and temperature are lower than the critical point, and the oil fraction (= lubricating oil amount / (lubricating oil amount + refrigerant amount)) in the gas-liquid separator 500 is, as shown in FIG. The lubricating oil and the refrigerant are separated such that the water accumulates below the refrigerant.

FIG. 18A shows a state where the compressor 100 is stopped, and FIG. 18B shows a state where the compressor 100 is operating. When the compressor 100 is stopped, the lubricating oil and the refrigerant are not clearly separated from each other when the compressor 100 is stopped, but when the compressor 100 is stopped at a predetermined liquid level or less. A high concentration of lubricating oil is present as well.

When the lubricating oil flows into the evaporator 300, the lubricating oil adheres to the inner wall of the evaporator 300 and lowers the heat transfer coefficient. Is desirable. For this purpose, the refrigerant inlet 50
It is desirable to dispose 4a near the liquid level (the interface between the liquid-phase refrigerant and the gas-phase refrigerant). However, since the liquid level fluctuates due to the heat load of the air conditioner, the lowest level when the liquid level fluctuates is actually It is necessary to arrange the refrigerant inlet 504a below the liquid level.

However, if the refrigerant inlet 504a is arranged below the lowermost liquid level, as described above, the refrigerant inlet 504a
Since a approaches the oil surface (the interface between the refrigerant and the lubricating oil),
If the refrigerant inlet 504a is opened downward,
As shown in FIG. 19A, the flow of the liquid refrigerant from the lower side to the upper side (the refrigerant inlet 504a side) is generated near the refrigerant inlet 504a, so that the lubricating oil is involved in the flow of the liquid refrigerant. Therefore, there is a high possibility that a large amount of lubricating oil is sucked into the liquid refrigerant outflow pipe 504 together with the liquid refrigerant.

Further, in order to set the lowest liquid level when the liquid level fluctuates to be located at a height sufficiently distant from the oil level, the vertical dimension of the tank section 501 is enlarged to increase the liquid level. The gas-liquid separator 500
Causes an increase in the vertical dimension.

On the other hand, in the present embodiment, since the refrigerant inlet 504a is open upward, FIG.
As shown in (b), in the vicinity of the refrigerant inlet 504a,
Since the flow of the liquid-phase refrigerant from the upper side to the lower side (the refrigerant inlet 504a side) is generated, the possibility that the lubricating oil is involved in the flow of the liquid-phase refrigerant is extremely low.

Therefore, it is possible to prevent a large amount of lubricating oil from being sucked into the liquid refrigerant outflow pipe 504 together with the liquid refrigerant, and to prevent the vertical dimension of the gas-liquid separator 500 from increasing.

FIG. 20 shows the case where the refrigerant inlet 504a is opened downward (FIG. 19A) and the case where the refrigerant inlet 504a is opened upward (FIG. 19).
It is a test result which shows the lubricating oil amount in the refrigerant | coolant supplied to the evaporator 300 in (b)), and according to this embodiment, as is clear from FIG. The amount of lubricating oil can be reduced.

(Ninth Embodiment) This embodiment is a modification of the eighth embodiment. Specifically, as shown in FIG.
Tubular pipe portion 504 of liquid-phase refrigerant outflow pipe 504
b from the side of the tank 501 substantially horizontally.
1 and a coolant inlet 504a is provided on the side surface of the pipe portion 504b. Note that the inner end of the pipe portion 504b inside the tank portion 501 is closed.

As a result, the liquid-phase refrigerant outflow pipe 504
The space occupied by the liquid-phase refrigerant outflow pipe 504 in the tank portion 501 is smaller than when the (pipe portion 504b) is bent into a U-shape or an L (J) shape, so that the gas-liquid separator 500 is small. Can be

(Tenth Embodiment) This embodiment is a modification of the eighth embodiment. Specifically, as shown in FIG. 22, a liquid-phase refrigerant outflow pipe 504 (pipe section 504b) is connected to a tank section 501. From the lower side of the tank 50 in a substantially vertical direction.
1. The refrigerant inlet 504a is inserted and mounted in the inside 1 so that the refrigerant inlet 504a is opened upward.

(Eleventh Embodiment) This embodiment is a modification of the eighth embodiment. Specifically, as shown in FIG. 23, a liquid-phase refrigerant outflow pipe 504 (pipe section 504b) is connected to a tank section 501. From above the tank 50 in a substantially vertical direction.
1, and a refrigerant inlet 504a is provided on the side surface of the pipe portion 504b to open the refrigerant inlet 504a in the horizontal direction. The inner end of the pipe portion 504b inside the tank portion 501 is closed.

In this embodiment, as in the eighth embodiment, the flow of the liquid-phase refrigerant from the lower side toward the refrigerant inlet 504a can be suppressed, so that the refrigerant inlet 504a is moved downward. The possibility that the lubricating oil is caught in the flow of the liquid-phase refrigerant can be reduced as compared with the case where the opening is directed toward the liquid-phase refrigerant.

Therefore, it is possible to prevent a large amount of lubricating oil from being sucked into the liquid-phase refrigerant outflow pipe 504 together with the liquid-phase refrigerant, and to prevent the vertical dimension of the gas-liquid separator 500 from increasing.

(Twelfth Embodiment) This embodiment is a modification of the eighth embodiment. Specifically, as shown in FIGS. 24 and 25, a refrigerant inlet 504a is provided at the tip end of a pipe portion 504b.
Is provided with a suction port forming member 504c that opens horizontally or upwards to form a refrigerant inlet 504a, and an oil discharge port 504d that opens downward is provided below the suction port forming member 504c. Things.

At this time, in this embodiment, by setting the pressure loss at the oil outlet 504d to be greater than the pressure loss at the refrigerant inlet 504a, the lubricating oil is formed from the oil outlet 504d. It is prevented from being sucked into the member 504c.

As a result, the lubricating oil accumulated in the suction port forming member 504c can be discharged from the oil discharge port 504d while preventing the lubricating oil from being entrained in the flow of the liquid phase refrigerant and flowing into the refrigerant inlet 504a. Therefore, it is possible to reliably prevent a large amount of lubricating oil from being sucked into the liquid refrigerant outflow pipe 504 together with the liquid refrigerant.

FIG. 24 shows an example in which the suction port forming member 504c is a cube, and FIG.
c is an umbrella.

(Thirteenth Embodiment) This embodiment is different from the thirteenth embodiment shown in FIG.
As shown in FIG. 7, a mesh filter 504e for preventing foreign substances from being sucked into the liquid-phase refrigerant outflow pipe 504 is provided on the refrigerant inlet 504a side.

FIG. 26 shows a case where the present embodiment is applied to the gas-liquid separator 500 according to the eighth embodiment. However, the present embodiment is not limited to this, and may be applied to other embodiments. Can be applied.

(Other Embodiments) In the above-described embodiment, the lubricating oil is returned from the gas-liquid separator 500 or the evaporator 300 to the compressor 100. However, the present invention is not limited to this. The lubricating oil may be returned to the compressor 100 from another portion such as a portion between the refrigerant outlet and the gas-liquid separator 500.

In the third to fifth embodiments, the heating means is provided based on the ejector cycle according to the first embodiment. However, the present invention is not limited to this, and is applicable to the second embodiment and the like. May be.

In the above embodiments, carbon dioxide or chlorofluorocarbon is used as the refrigerant. However, the present invention is not limited to this. For example, hydrocarbon refrigerants such as ethylene, ethane, nitrogen oxide, and propane may be used. Other refrigerants may be used.

The lubricating oil is polyglycol (PA
The mineral oil such as G) is not limited to the above, and other oils may be used. At this time, the oil return pipe 5
The connection position of 10 needs to be appropriately selected in consideration of the difference between the liquid density of the refrigerant and the liquid density of the lubricating oil.

In the sixth embodiment, the oil inlet 5
11, the oil suction port 511 was displaced in accordance with the liquid level fluctuation so as to be located at a predetermined depth with respect to the liquid level. On the basis of the surface fluctuation range, the oil suction port 51 is set so that the oil suction port 511 is located at a predetermined depth range with respect to the liquid level.
1 may be fixedly arranged.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an ejector cycle according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of an ejector applied to the ejector cycle according to the first embodiment of the present invention.

FIG. 3 is a schematic diagram of a gas-liquid separator applied to an ejector cycle according to the first embodiment of the present invention.

FIG. 4 is a ph (Mollier) diagram of an ejector cycle according to the first embodiment of the present invention.

FIG. 5 is a schematic view of an ejector cycle according to a second embodiment of the present invention.

FIG. 6 is a schematic diagram of an ejector cycle according to a third embodiment of the present invention.

FIG. 7 is a schematic view of an ejector cycle according to a fourth embodiment of the present invention.

FIG. 8 is a schematic view of an ejector cycle according to a fifth embodiment of the present invention.

FIG. 9 is a schematic view of a gas-liquid separator applied to an ejector cycle according to a sixth embodiment of the present invention.

FIG. 10 is a schematic diagram of a gas-liquid separator applied to an ejector cycle according to a sixth embodiment of the present invention.

FIG. 11 is a schematic diagram of a gas-liquid separator applied to an ejector cycle according to a seventh embodiment of the present invention.

FIG. 12 is a perspective view of an inflow prevention plate applied to a gas-liquid separator according to a seventh embodiment of the present invention.

13A is a schematic diagram of a gas-liquid separator without an inflow prevention plate, and FIG. 13B is a schematic diagram of a gas-liquid separator according to a seventh embodiment.

FIG. 14 shows the proportion of lubricating oil in the refrigerant flowing into the evaporator (evaporator inlet oil rate) and the proportion of lubricating oil in the refrigerant flowing into the compressor (compressor suction oil rate).
6 is a graph showing a relationship with the graph.

FIG. 15 is a schematic diagram of a gas-liquid separator applied to an ejector cycle according to an eighth embodiment of the present invention.

FIG. 16 is a schematic diagram of a gas-liquid separator applied to an ejector cycle according to an eighth embodiment of the present invention.

FIG. 17 is a characteristic diagram showing compatibility between a lubricating oil (PAG) and a refrigerant (carbon dioxide).

FIG. 18A is a schematic diagram illustrating a state of lubricating oil and a refrigerant in the gas-liquid separator when the compressor is stopped,
(B) is a schematic diagram showing a state of the lubricating oil and the refrigerant in the gas-liquid separator when the compressor is operating.

FIG. 19A is a schematic diagram illustrating a gas-liquid separator in which a refrigerant inlet faces downward, and FIG. 19B is a schematic diagram illustrating a gas-liquid separator in which a refrigerant inlet faces upward.

FIG. 20 is a bar graph showing an effect of the gas-liquid separator according to the eighth embodiment of the present invention.

FIG. 21 is a schematic view of a gas-liquid separator according to an eighth embodiment of the present invention.

FIG. 22 is a schematic view of a gas-liquid separator according to a ninth embodiment of the present invention.

FIG. 23 is a schematic view of a gas-liquid separator according to a tenth embodiment of the present invention.

FIG. 24 is a schematic view of a gas-liquid separator according to an eleventh embodiment of the present invention.

FIG. 25 is a schematic view of a gas-liquid separator according to an eleventh embodiment of the present invention.

FIG. 26 is a schematic view of a gas-liquid separator according to a twelfth embodiment of the present invention.

FIG. 27 is a graph showing the relationship between the refrigeration capacity, the amount of oil in the evaporator, and the elapsed time.

[Explanation of symbols]

100: compressor, 200: radiator, 300: evaporator, 4
00: ejector, 500: gas-liquid separator, 510: oil return circuit.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kazuhisa Makita 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside Denso Corporation (72) Inventor Masayuki Takeuchi 1-1-1, Showa-cho, Kariya City, Aichi Prefecture Denso Corporation (72) Inventor Hiroshi Ishikawa 1-1-1 Showa-cho, Kariya-shi, Aichi Prefecture Inside DENSO Corporation

Claims (16)

[Claims] 1. A compressor (100) for sucking and compressing a refrigerant.
A radiator (200) for radiating heat of the refrigerant discharged from the compressor (100); an evaporator (300) for exhibiting a heat absorbing effect by evaporating the refrigerant; and an outflow from the radiator (200). A nozzle (410) for converting the pressure energy of the high-pressure refrigerant into velocity energy to decompress and expand the refrigerant, and a gas-phase refrigerant evaporated in the evaporator (300) by the high-speed refrigerant flow injected from the nozzle (410). A mixing section (420) for sucking the air, and a refrigerant injected from the nozzle (410) and the evaporator (30).
Ejector (400) having a diffuser (430) that converts velocity energy into pressure energy while increasing the pressure of the refrigerant while mixing the refrigerant sucked from 0).
A gas-liquid separator (500) that stores the refrigerant by separating the refrigerant into a gaseous refrigerant and a liquid-phase refrigerant, and an oil return circuit ( 510). 2. The oil return circuit (510) is connected to the gas-liquid separator (500) and is configured to return lubricating oil separated from refrigerant to a suction side of the compressor (100). The ejector cycle according to claim 1, wherein 3. The oil return circuit (510) removes lubricating oil accumulated in the evaporator (300) to the compressor (1).
2. The ejector cycle according to claim 1, wherein the ejector cycle is configured to return to a suction side of the ejector. 4. Heating means (520, 530, 54) for heating a fluid flowing in the oil return circuit (510).
The ejector cycle according to any one of claims 1 to 3, wherein 0) is provided. 5. A heat exchanger (530) for exchanging heat between a fluid before being absorbed by the evaporator (300) and a fluid flowing in the oil return circuit (510). An ejector cycle according to any one of claims 1 to 3. 6. A heat exchanger (540) for exchanging heat between high-pressure refrigerant discharged from the compressor (100) and fluid flowing in the oil return circuit (510). The ejector cycle according to any one of claims 1 to 3. 7. The gas-liquid separator (500) side of the oil return circuit (510) is connected to a portion of the gas-liquid separator (500) where the lubricating oil concentration is higher than the refrigerant concentration. The ejector cycle according to claim 2, wherein: 8. The gas-liquid separator for an ejector cycle according to claim 1, wherein a lubricating oil having a density greater than a density of the liquid-phase refrigerant is used, wherein a tank (501) for storing the refrigerant and the lubricating oil is provided. A liquid-phase refrigerant outlet (504) for supplying a liquid-phase refrigerant to the evaporator (300) side, and a gas-phase refrigerant to a suction side of the compressor (100) in the tank section (501). And the oil return circuit (51).
An oil return port (505) to which the ejector (400) is connected is provided above the liquid-phase refrigerant outlet port (504). A gas-liquid separator, further comprising an inflow suppressing member (506) for suppressing the inflow to the liquid-phase refrigerant outlet (504). 9. The gas-liquid separator according to claim 8, wherein the inflow suppressing member (506) is formed in an umbrella shape such that an upper side is convex. 10. The gas-liquid separator according to claim 9, wherein a through hole (506a) is provided at an upper end of the inflow suppressing member (506). 11. The gas-liquid separator for an ejector cycle according to claim 1, wherein a lubricating oil having a density higher than a density of the liquid-phase refrigerant is used, wherein a tank (501) for storing the refrigerant and the lubricating oil is provided. The tank unit (501) includes the tank unit (501).
Liquid-phase refrigerant outlet pipe (504) for supplying the liquid-phase refrigerant inside to the evaporator (300) side, the tank part (501)
A gas-phase refrigerant outlet pipe (503) for supplying a gas-phase refrigerant inside the compressor to the suction side of the compressor (100); and an oil return port (505) to which the oil return circuit (510) is connected. Further, a refrigerant suction port (504a) of the liquid-phase refrigerant outflow pipe (504) opened in the tank section (501).
Is a gas-liquid separator characterized by being open horizontally or upward. 12. The liquid-phase refrigerant outflow pipe (504) having the refrigerant suction port (504a) facing the tank portion (50).
1), the refrigerant inlet (50) is bent.
The gas-liquid separator according to claim 11, wherein 4a) is configured to open horizontally or upward. 13. The liquid refrigerant outflow pipe (504) has a tubular pipe part (50).
The gas-liquid separator according to claim 11, wherein the gas-liquid separator is provided on a side surface of 4b). 14. The liquid-phase refrigerant outflow pipe (504) includes a tubular pipe part (504b) and the pipe part (504).
The gas-liquid separator according to claim 11, further comprising a suction port forming member (504c) connected to b) to form the refrigerant suction port (504a). 15. An oil discharge port (50) opening downward is provided below the suction port forming member (504c).
The gas-liquid separator according to claim 11, wherein 4d) is provided. 16. The refrigerant suction port (504a) includes:
16. A filter means (504e) for preventing foreign matter from being sucked into the liquid-phase refrigerant outflow pipe (504).
The gas-liquid separator according to any one of the first to third aspects.