JP2005233470A - Gas-liquid separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas-liquid separator capable of reducing the speed energy loss of a refrigerant in a separation space. <P>SOLUTION: A liquid outflow port 19a is disposed so as to face a swing flow S when the two-phase refrigerant IN flowing into the separation space 18 is swung in the separation space 18 through an inner wall 18a. The liquid-phase refrigerant swinging along the swing flow S flows out at the lower part of the separation space 18. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a gas-liquid separator that separates a gas-liquid two-phase fluid into a gas-phase fluid and a liquid-phase fluid, and is effective when applied to a gas-liquid separator for an ejector cycle.

  Conventionally, a gas-liquid separator having a general structure that separates a gas-liquid two-phase refrigerant into a gas-phase refrigerant and a liquid-phase refrigerant and stores excess refrigerant therein is referred to as Patent Document 1 (hereinafter referred to as Conventional Example 1). ) And Patent Document 2 (hereinafter referred to as Conventional Example 2). In the gas-liquid separators 50 and 52 of the conventional example 1 in FIG. 7 and the conventional example 2 in FIG. 8, the liquid outlet 19a through which the liquid-phase refrigerant flows out is disposed at the lowermost part of the separation space 18, It opens toward the upper direction in the installation state of the containers 50 and 52. Reference numeral 51 denotes an outflow conduit 51 for oil supplied to the compressor.

Thereby, a liquid refrigerant can be made to flow out from the lowest part of separation space 18 where a liquid refrigerant accumulates.
JP 2002-349978 A Japanese Patent Laid-Open No. 2003-202168

  However, in the conventional example 1 and the conventional example 2, after the liquid refrigerant once has a velocity energy of approximately 0 in the separation space 18, the refrigerant's own weight (potential energy) and the refrigerant transport means downstream of the liquid outlet 19a. It flows out by the suction energy (for example, ejector etc.). For this reason, the outflow speed becomes low, and in the worst case, the refrigerant stays downstream of the liquid outlet 19a.

  In view of the above points, an object of the present invention is to reduce the flow rate of refrigerant flowing out of the gas-liquid separator, in other words, to reduce the loss of velocity energy of the refrigerant in the gas-liquid separator.

In order to achieve the above object, according to the first aspect of the present invention, in the gas-liquid separator, the inlet (17a) into which the fluid in the gas-liquid two-phase state flows and the fluid in the gas-liquid two-phase state are in the liquid phase. Separation space (18) for separating fluid and gas phase fluid, gas outlet (20a) from which gas phase fluid flows out from separation space (18), and liquid outlet from which liquid phase fluid flows out from separation space (18) (19a)
The gas-liquid two-phase fluid is swirled in the separation space (18), and the liquid outlet (19a) is below the separation space (18) and toward the swirling flow (S) of the fluid. It is characterized by being arranged to open.

  According to this, since the fluid in the gas-liquid two-phase state swirls in the separation space (18), the liquid-phase fluid accumulated in the lower portion of the separation space (18) also swirls together. Since the liquid outlet (19a) is arranged so as to open toward the swirling flow (S) of the fluid, the liquid phase fluid can be discharged from the liquid outlet (19a) without loss of velocity energy. . Accordingly, it is possible to reduce the decrease in the outflow speed of the liquid phase fluid flowing out from the liquid outlet (19a), that is, the loss of the velocity energy of the fluid in the gas-liquid separator. Thereby, it is possible to prevent the fluid from staying downstream of the liquid outlet (19a).

Moreover, in invention of Claim 2, it is an ejector cycle using the gas-liquid separator of Claim 1,
A compressor (11) that sucks and compresses the gas phase fluid, a radiator (12) that radiates heat of the gas phase fluid discharged from the compressor (11), and an endothermic effect by evaporating the liquid phase fluid. The depressurization means for decompressing and expanding the high-pressure gas-phase fluid flowing out from the evaporator (16) and the radiator (12), and the fluid evaporated in the evaporator (16) by the entrainment action of the high-speed working fluid An ejector (13) which is a momentum transporting pump for sucking and transporting,
The fluid flowing out from the ejector (13) flows into the inlet (17a).

  According to this, the fluid flowing out from the ejector (13), that is, the gas-liquid two-phase fluid, flows into the separation space (18), and is separated into the liquid phase fluid and the gas phase fluid in the separation space (18). And a liquid fluid can be made to flow in into an evaporator (16) from a liquid outlet (19a) in the state where there is little loss of velocity energy which it has at the time of inflow. For this reason, the speed of the liquid fluid flowing into the evaporator (16) is increased, and it is possible to prevent the fluid from staying in the evaporator (16). Furthermore, since the amount of fluid that can flow into the evaporator (16) increases, the evaporator (16) can exhibit a larger heat absorption effect, and the refrigeration efficiency of the ejector cycle can be improved.

  By the way, when the gas-liquid separators of the conventional example 1 and the conventional example 2 are applied to the ejector cycle, the velocity energy of the liquid-phase fluid that has once become substantially zero in the gas-liquid separator is converted to the fluid by the compressor (11). It must be lifted again, such as by compression suction. However, since the gas-liquid separator according to claim 1 is used in the ejector cycle according to claim 2, the loss of the velocity energy of the fluid in the gas-liquid separator is small. That is, since the fluid compression suction operation by the compressor (11) can be reduced, the energy efficiency of the entire ejector cycle can be increased.

  Further, as in the invention described in claim 3, in the ejector cycle described in claim 2, a fluid having a large density ratio may be used.

  Further, as in the invention according to claim 4, in the ejector cycle according to claim 3, any one of the refrigerants R404A, HC, R134a, R410A, and R407C is used as the fluid having a large density ratio. Also good.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
In the present embodiment, the gas-liquid separator according to the present invention is applied to an ejector (refrigeration) cycle of a vehicle air conditioner using an ejector, and FIG. 1 is a schematic diagram of the present embodiment. In FIG. 1, 11 is a compressor 11 that sucks and compresses refrigerant. The refrigerant that has become a high pressure state by the compressor 11 flows into the radiator 12. In the radiator 12, the refrigerant radiates heat to the outdoor air, in other words, the refrigerant is cooled by the outdoor air.

  The cooled refrigerant flows into the ejector 13. The ejector 13 functions as a refrigerant decompression unit and a refrigerant circulation unit in the refrigeration cycle. The refrigerant flowing into the ejector 13 is converted from pressure energy to velocity energy at the nozzle portion inside the ejector 13. And the gaseous-phase refrigerant | coolant evaporated by the evaporator 16 mentioned later by the entrainment effect | action of the working fluid ejected from a nozzle at high speed is attracted | sucked. Further, the expansion energy of the refrigerant is converted into pressure energy in the diffuser portion where the passage area of the refrigerant is increased, and the suction pressure of the compressor 11 downstream of the refrigerant flow of the ejector 13 is increased.

  The refrigerant that has flowed out of the ejector 13 flows through the refrigerant inflow conduit 17 and flows into the gas-liquid separator 14. At this time, the refrigerant flowing out of the ejector 13 is in a gas-liquid two-phase state due to the pressure reducing action of the ejector 13. In the gas-liquid separator 14, the refrigerant that has flowed is separated into a gas-phase refrigerant and a liquid-phase refrigerant and stored, and the separated gas-phase refrigerant is sucked into the compressor 11 and compressed again. The liquid refrigerant thus drawn is sucked to the evaporator 16 side. The gas-liquid separator 14 will be described later.

  The evaporator 16 exhibits cooling capability by heat-exchanging the liquid-phase refrigerant with the air blown into the room and evaporating. The first decompressor 15 disposed between the gas-liquid separator 14 and the evaporator 16 is a throttle (decompression) means for decompressing the liquid-phase refrigerant sucked from the gas-liquid separator 14 to the evaporator 16 side. The pressure in the evaporator 16 (evaporation pressure) is reliably reduced by the first decompressor 15.

In this embodiment, R404A, which is a fluid having a large density ratio obtained by dividing the liquid phase density by the gas phase density, is used as the refrigerant. Vapor density of R404A is about 42 kg / ^{m 3,} the liquid phase density is about 1134kg / ^{m 3.}

  Next, the details of the gas-liquid separator 14 will be described using the side view of FIG. 2 and the plan view of FIG. 3. The gas-liquid separator 14 has a substantially cylindrical separation space 18. In this separation space 18, an inflow port 17 a of an inflow conduit 17 through which the gas-liquid two-phase refrigerant flowing out from the ejector 13 flows (arrow IN in the figure) is disposed. The inflow port 17a is slightly above the middle of the vertical length of the separation space 18 and so that the two-phase refrigerant flow flowing into the separation space 18 is in the direction of the outer tangent to the separation space 18 in plan view (FIG. 3). It is open. In addition, the up and down arrows in the figure indicate the up and down direction in the installed state of the gas-liquid separator 14.

  The two-phase refrigerant flow IN flowing into the separation space 18 becomes a flow S that swirls in the separation space 18 by the inner wall 18 a that forms the separation space 18. Among the two-phase refrigerants, particularly the liquid-phase refrigerant has a high density, and therefore falls downward due to gravity while turning (see an arrow S in FIG. 2) and accumulates below the separation space 18. On the other hand, since the gas-phase refrigerant has a low density, it accumulates on the upper side of the separation space 18.

  A liquid outflow pipe 19 through which the separated liquid refrigerant flows out is disposed at the lowermost part of the separation space 18, and this liquid outflow pipe 19 has a liquid outflow port 19 a directed to the swirling flow S described later. . In other words, the tangential direction of the swirl flow S in a plan view (FIG. 3) and the direction of the liquid refrigerant flow Lout flowing out from the liquid outlet 19a through the liquid outlet pipe 19 coincide with each other. The liquid outlet 19 a is arranged so that the liquid refrigerant flow Lout flowing out from the separation space 18 is in the outer tangent direction of the separation space 18.

  On the other hand, the separated gas-phase refrigerant flows out from the gas outflow conduit 20. The gas outlet 20 a of the gas outlet pipe 20 is located above the inlet 17 a in the separation space 18. As a result, only the gas refrigerant accumulated on the upper side of the separation space 18 can be caused to flow out without causing the liquid-phase refrigerant in the two-phase flow flowing into the separation space 18 to flow out.

  Next, the effects of the first embodiment will be listed. (1) Since the liquid outlet 19a opens toward the swirling flow S, the liquid-phase refrigerant is allowed to flow out of the liquid outlet 19a without loss of velocity energy. be able to.

  More specifically, the two-phase refrigerant flowing into the separation space 18 becomes a swirl flow along the inner wall 18a, and the liquid-phase refrigerant that accumulates in the lower portion of the separation space 18 also swirls along the inner wall 18a. Since the liquid outlet 19a opens so that the tangential direction of the swirl flow S in a plan view (FIG. 3) and the direction of the liquid refrigerant flow Lout flowing out from the liquid outlet 19a coincide with each other, the liquid-phase refrigerant has a velocity. It flows out from the liquid outlet 19a without energy loss.

  Thereby, the loss of the kinetic energy of the refrigerant | coolant which flows in into the gas-liquid separator 14 can be reduced. That is, the speed of the liquid refrigerant flowing into the evaporator 16 arranged downstream of the liquid outflow pipe 19 can be increased. Thereby, the refrigerant | coolant inflow amount into the evaporator 16 can be increased, the heat exchange efficiency in the evaporator 16 can be made high, and the refrigerating capacity can be improved. According to the evaluation by the present inventors, in the refrigerator using R404A as the refrigerant, the effect of improving the refrigerating capacity by 60% is confirmed by the structure of the present embodiment.

  Further, when the speed of the liquid refrigerant flowing into the evaporator 16 increases, the refrigerant speed in the evaporator 16 also increases, so that the refrigerant in the evaporator 16 and the retention of oil contained in the refrigerant can be reduced. . According to the evaluation by the present inventors, it has been confirmed that in a refrigerator using R404A as a refrigerant, the required refrigerant amount at the same refrigeration capacity can be reduced by 30%.

  By the way, when the gas-liquid separators 50 and 52 of the conventional example 1 (FIG. 7) and the conventional example 2 (FIG. 8) are applied to the ejector cycle, the gas-liquid separators 50 and 52 once become substantially zero. The speed energy of the liquid refrigerant must be increased again by the compression and suction of the refrigerant by the compressor 11. However, in the present embodiment, the loss of the velocity energy of the refrigerant in the gas-liquid separator 14 is small, that is, the refrigerant compression / suction operation by the compressor 11 can be reduced, so that the energy efficiency of the entire ejector cycle is increased. Can do.

  (2) Since the liquid outlet 19a is arranged so that the liquid refrigerant flow Lout flowing out from the lowermost part of the separation space 18 and the separation space 18 is in the outer tangent direction of the separation space 18, the liquid outlet 19a It is possible to reduce the outflow of the phase refrigerant.

  By the way, in recent years, the amount of refrigerant used has been reduced to the bare minimum due to problems such as environmental impact. Accordingly, the refrigerant stored in the gas-liquid separator 14 is naturally reduced. FIG. 4 shows a state where the amount of the liquid refrigerant L in the present embodiment is small, and is a view as viewed from A in FIG.

  The two-phase refrigerant flow that has flowed into the separation space 18 from the inflow port 17a swirls in the separation space 18 as indicated by an arrow S by the inner wall 18a that forms the separation space 18. At this time, since the liquid-phase refrigerant L accumulated in the lower portion of the separation space 18 also rotates, the liquid level becomes higher as the inner wall 18a is approached due to centrifugal force. On the contrary, the liquid level becomes low near the center of the swirl flow S. The liquid outlet 19a of the present embodiment is disposed near the inner wall 18a where the liquid level is highest, that is, at a position where the liquid refrigerant flow Lout flowing out from the separation space 18 is substantially the same as the direction of the outer tangent line of the separation space 18. Yes. Therefore, the high liquid level can reduce the outflow of the gas-phase refrigerant from the liquid outlet 19a even when the amount of the liquid refrigerant is reduced.

  The difference in liquid level between the vicinity of the inner wall 18a and the vicinity of the center of the swirl flow S becomes larger as the fluid has a larger density ratio obtained by dividing the density of the liquid phase by the density of the gas phase. Therefore, it is possible to reduce the outflow of the gas-phase refrigerant from the liquid outlet 19a even if the amount of refrigerant is smaller as the density ratio is larger.

  (3) In plan view (FIG. 3), since the inflow port 17a is opened so that the two-phase refrigerant flow IN flowing into the separation space 18 is in the outer tangent direction of the separation space 18, a larger swirl flow S is generated. The energy loss in the gas-liquid separator 14 can be reduced.

(Second Embodiment)
In the first embodiment, the gas outflow pipe 20 is taken out from the lower part of the separation space 18 to the outside of the separation space 18, but in this embodiment, the gas flow pipe 20 is taken out from the side of the separation space 18 to the outside of the separation space 18. (See FIG. 5). If the gas outlet 20a is opened above the inlet 17a, the gas-phase refrigerant can be satisfactorily sucked. Therefore, even if the gas outlet 20 is taken out from the side surface of the separation space 18 as in the present embodiment, the gas outlet 20a is There is no influence on the separation performance of the liquid separator 14.

  Thereby, the design freedom degree of arrangement | positioning of the gas outflow pipeline 20 can be made high.

  In addition, also in this embodiment, the effect of (1)-(3) of 1st Embodiment can be exhibited.

(Third embodiment)
In the first and second embodiments, the inlet 17a is opened so that the two-phase refrigerant flow IN flowing into the separation space 18 is in a direction tangential to the outer periphery of the separation space 18 in plan view. You may arrange | position toward the center in the planar view of the separation space 18 (refer FIG. 6).

  Also by this, the swirling flow S is generated by the inner wall 18 a of the separation space 18. Therefore, the effects (1) and (2) of the first embodiment can be exhibited.

(Other embodiments)
In the first to third embodiments described above, the example in which the refrigerant is R404A has been described, but the refrigerant can be variously changed such as HC, R134a, R410A, and R407C. Further, the gas-liquid separator of the present invention is not limited to the refrigerant and can be applied to a fluid in a two-phase state.

  In the first to third embodiments described above, the example in which the gas-liquid separator of the present invention is applied to the ejector cycle of the vehicle air conditioner has been shown. However, the present invention is not limited to the vehicle air conditioner, and CO2 is used as a refrigerant. The ejector cycle used for other uses, such as the used heat pump cycle for hot water supply, may be used.

It is a schematic diagram which shows the ejector cycle of 1st Embodiment which applied the gas-liquid separator of this invention to the vehicle air conditioner. It is a side view of the gas-liquid separator which concerns on 1st Embodiment. It is a top view of the gas-liquid separator which concerns on 1st Embodiment. It is A view of the gas-liquid separator of FIG. It is a side view of the gas-liquid separator which concerns on 2nd Embodiment. It is a top view of the gas-liquid separator which concerns on 3rd Embodiment. It is a side view of the gas-liquid separator concerning patent documents 1. It is a side view of the gas-liquid separator concerning patent documents 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Compressor, 12 ... Radiator, 13 ... Ejector, 16 ... Evaporator, 17a ... Inlet,
18 ... Separation space, 19a ... Liquid outlet, 20a ... Gas outlet.

Claims (4)

A separation space (18) into which a gas-liquid two-phase fluid flows from the inlet (17a) and separates into a liquid-phase fluid and a gas-phase fluid;
A gas outlet (20a) through which the gaseous fluid flows out of the separation space (18);
A liquid outlet (19a) through which the liquid phase fluid flows out from the separation space (18),
The gas-liquid two-phase fluid swirls in the separation space (18),
The gas-liquid separator, wherein the liquid outlet (19a) is disposed below the separation space (18) and so as to open toward the swirling flow (S) of the fluid. An ejector cycle using the gas-liquid separator according to claim 1,
A compressor (11) for sucking and compressing the gas phase fluid;
A radiator (12) for radiating heat of the gas-phase fluid discharged from the compressor (11);
An evaporator (16) that exerts an endothermic effect by evaporating the liquid phase fluid;
A momentum for sucking and transporting the fluid evaporated by the evaporator (16) by the entrainment action of the high-speed working fluid as well as decompression means for decompressing and expanding the high-pressure gas-phase fluid flowing out from the radiator (12) Ejector (13) which is a transport pump,
The ejector cycle characterized in that the fluid flowing out from the ejector (13) flows into the inlet (17a). The ejector cycle according to claim 2, wherein the fluid is a fluid having a large density ratio obtained by dividing the density of the liquid phase by the density of the gas phase. The ejector cycle according to claim 3, wherein the fluid having a large density ratio is any one of R404A, HC, R134a, R410A, and R407C that are refrigerants.

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