JP4333556B2 - Gas-liquid separator for ejector cycle - Google Patents

Description

  The present invention relates to a gas-liquid separator for an ejector cycle.

In the ejector cycle, the refrigerant and refrigeration oil are separated by the specific gravity difference in the gas-liquid separator, and the heat exchange amount of the low-pressure side heat exchanger is prevented from decreasing due to the refrigeration oil flowing into the low-pressure side heat exchanger. (For example, refer to Patent Document 1).
JP 2002-130874 A

  However, in the ejector cycle described in Patent Document 1, since the volume of the liquid storage part in the gas-liquid separator is small, a sufficient separation time cannot be obtained. Since it will flow out to the exchanger side, the oil circulation rate to the low pressure side heat exchanger will become high. As a result, the heat transfer coefficient of the low-pressure side heat exchanger is reduced and the pressure loss is increased, which leads to a problem that the coefficient of performance (COP) of the cycle is lowered.

  In view of the above points, an object of the present invention is to suppress the refrigerating machine oil from flowing out to the low pressure side heat exchanger side together with the liquid phase refrigerant in the ejector cycle gas-liquid separator.

In order to achieve the above object, according to the first aspect of the present invention, the compressor (1) for increasing the pressure of the refrigerant mixed with refrigerating machine oil and the high pressure for allowing the high-pressure refrigerant flowing out from the compressor (1) to cool. The side heat exchanger (2), the low pressure side heat exchanger (3) for evaporating the low pressure refrigerant, the refrigerant flowing out from the high pressure side heat exchanger (2) is decompressed and expanded, and the decompressed refrigerant and the low pressure This is applied to an ejector cycle that includes an ejector (4) that mixes and boosts the refrigerant sucked from the side heat exchanger (3), and separates the refrigerant that has flowed out of the ejector (4) into a gas-phase refrigerant and a liquid-phase refrigerant. A gas-liquid separator (5) for supplying the gas-phase refrigerant to the suction side of the compressor (1) and supplying the liquid-phase refrigerant to the low-pressure side heat exchanger (3),
An inlet (52) through which refrigerant flowing out from the ejector (4) flows in, a gas phase refrigerant outlet (53) through which gas phase refrigerant flows out, a liquid phase refrigerant outlet (54) through which liquid phase refrigerant flows out, and refrigeration It has an oil return port (55) through which machine oil flows out, and the inlet (52) and the gas-phase refrigerant outlet (53) are located above the liquid-phase refrigerant outlet (54) and the oil return port (55). And a coarsening member (56) for increasing the particle size of the refrigerating machine oil as compared with that before passing when the liquid-phase refrigerant passes , and the coarsening member (56) includes the inlet (52) and Arranged between the gas-phase refrigerant outlet (53), the liquid-phase refrigerant outlet (54), and the oil return port (55) and below the liquid level of the mixed-phase fluid of the liquid-phase refrigerant and the refrigerating machine oil. It is characterized by being.

  According to this, since the settling speed of the refrigeration oil coarsened by passing through the coarsening member is increased, the separation efficiency between the liquid refrigerant and the refrigeration oil is improved. Therefore, the refrigerating machine oil can be prevented from flowing out to the low pressure side heat exchanger side together with the liquid phase refrigerant, thereby improving the heat transfer coefficient in the heat exchanger and reducing the pressure loss in the pipe. Thus, the coefficient of performance (COP) of the cycle can be improved.

  The invention according to claim 2 is characterized in that, in the gas-liquid separator for an ejector cycle according to claim 1, the coarsening member (56) is a fibrous member.

  According to this, when the fine oil particles in the liquid phase refrigerant adhere to the surface of the fibrous member, the adhered oil particles coalesce and aggregate, and when the oil particles are scattered from the fibrous member, the particle size is large. Therefore, the effect of the invention of claim 1 can be obtained with certainty.

  According to a third aspect of the present invention, in the gas-liquid separator for an ejector cycle according to the first aspect, the coarsening member (56) is a porous member.

  According to this, when fine oil particles in the liquid phase refrigerant adhere to the surface of the porous member, the adhering oil particles coalesce and aggregate, and when the oil particles are scattered from the porous member, the particle size Therefore, the effect of the invention of claim 1 can be obtained with certainty.

According to a fourth aspect of the present invention, in the gas-liquid separator for an ejector cycle according to any one of the first to third aspects, the liquid-phase refrigerant outlet (54) is located above the oil return port (55). and wherein it has been positioned with al.

  According to this, after separating the liquid phase refrigerant that passed through the coarsening member and the mixed fluid of the refrigeration oil due to the difference in specific gravity, the separated low-concentration liquid phase refrigerant is discharged to the low-pressure side heat exchanger side and separated. The subsequent refrigeration oil can be discharged to the compressor side.

  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.

  An embodiment of the present invention will be described. 1 is a configuration diagram of an ejector cycle including a gas-liquid separator according to an embodiment, FIG. 2 is a cross-sectional view of the gas-liquid separator of FIG. 1, and FIG. 3 is a schematic diagram for explaining the operation of the gas-liquid separator of FIG. FIG.

  In the ejector cycle of this embodiment, carbon dioxide is used as a refrigerant, and refrigerant oil for lubricating the compressor 1 is mixed in the refrigerant. As the refrigerating machine oil, polyalkyl group glycol (PAG) refrigerating machine oil is used.

  As shown in FIG. 1, in the ejector cycle, the compressor 1 that sucks and compresses the refrigerant to increase the pressure, and the high-temperature and high-pressure refrigerant discharged from the compressor 1 exchanges heat with an external fluid to radiate the heat of the refrigerant to the outside. A high-pressure side heat exchanger 2; a low-pressure side heat exchanger 3 that absorbs heat from the external fluid by evaporating the low-temperature and low-pressure refrigerant by exchanging heat with the external fluid; and a high-pressure side heat exchanger 2 and a low-pressure side heat exchanger 3, an ejector 4 for mixing and increasing the pressure of the refrigerant, a gas-liquid separator 5 for separating the gas-liquid two-phase refrigerant flowing out from the ejector 4 into a gas-phase refrigerant, a liquid-phase refrigerant, and refrigeration oil, and a compressor oil as a compressor And an oil return circuit 6 for returning to 1.

  The ejector 4 sucks the gas-phase refrigerant evaporated in the low-pressure side heat exchanger 3 and the nozzle that decompresses and expands the refrigerant flowing out from the high-pressure side heat exchanger 2, and converts the expansion energy into pressure energy to compress the compressor 10. A mixing part for increasing the suction pressure of the gas and a pressure increasing part composed of a diffuser.

  As shown in FIG. 2, the tank body 51 of the gas-liquid separator 5 includes an inlet 52 through which the refrigerant flowing out from the ejector 40 flows in, a gas-phase refrigerant outlet 53 through which the separated gas-phase refrigerant flows into the compressor 1, A liquid-phase refrigerant outlet 54 through which the separated liquid-phase refrigerant flows out to the low-pressure side heat exchanger 3 and an oil return hole 55 through which the separated refrigerator oil flows into the compressor 1 are provided.

  The tank-side openings of the inlet 52 and the gas-phase refrigerant outlet 53 are positioned higher than the tank-side openings of the liquid-phase refrigerant outlet 54 and the oil return port 55, and the tank-side opening of the liquid-phase refrigerant outlet 54. The part is provided above the tank side opening of the oil return hole 55.

  In addition, the tank side opening of the inflow port 52 is positioned above a later-described coarsening member, and the tank side opening of the gas-phase refrigerant outlet 53 is located at the top of the tank body 51, and the liquid phase refrigerant outlet The tank side opening 54 is positioned below the coarsening member described later, and the tank side opening of the oil return hole 55 is positioned at the bottom of the tank body 51.

  In the tank body 51, when a mixed phase fluid of the liquid phase refrigerant and the refrigerating machine oil passes, the coarse particles that aggregate the particles of the refrigerating machine oil floating in the liquid phase refrigerant and expand the particle diameter of the refrigerating machine oil. A granulating member 56 is provided.

  The coarse member 56 is disposed between the inlet 52 and the gas-phase refrigerant outlet 53, and the liquid-phase refrigerant outlet 54 and the oil return port 55. The coarse member 56 is made of polyethylene terephthalate (PET) in the form of a fiber or a porous body, and the gap or hole diameter between the fibers is set to 20 to 50 μm.

  Next, based on FIG. 2, FIG. 3, the effect | action of the oil separation in the gas-liquid separator 5 is demonstrated.

  2 and 3, the mixed phase fluid a in which the liquid phase refrigerant separated in the gas-liquid separator 5 and the refrigerating machine oil are mixed is a state in which fine oil particles x are suspended in the liquid phase refrigerant. When the mixed phase fluid a passes through the coarsening member 56, the oil particles x adhere to the surface of the fiber or porous body. When the adhering oil particles x coalesce and agglomerate and scatter from the coarse member 56, the particle diameter increases.

  Since the oil particles x having a larger particle diameter increase in the free settling speed, the separation of the refrigerating machine oil in the liquid-phase refrigerant is promoted, and the oil separation capacity of the gas-liquid separator 5 is improved. And the liquid phase refrigerant which passed the coarsening member 56, and the mixed phase fluid of refrigeration oil are isolate | separated by specific gravity difference, and the low-phase side heat exchanger from the liquid phase refrigerant | coolant outflow port 54 liquid phase refrigerant b of the low oil density | concentration after isolation | separation The refrigeration oil c after separation is caused to flow out to the compressor 1 side from the oil return hole 55.

  As described above, the oil separation capacity of the gas-liquid separator 5 is improved, so that the oil circulation rate in the refrigerant circulated from the liquid-phase refrigerant outlet 54 to the low-pressure side heat exchanger 3 is reduced. By reducing the oil circulation rate, the heat transfer rate of the low-pressure side heat exchanger 3 is improved, the pressure loss in the piping is reduced, and the coefficient of performance (COP) of the cycle is improved.

(Other embodiments)
The above-described ejector cycle can be applied to a water heater or an air conditioner.

  Further, the refrigerant is not limited to carbon dioxide, and may be other refrigerants such as Freon.

  The refrigerating machine oil is not limited to the PAG refrigerating machine oil, and other refrigerating machine oils such as POE refrigerating machine oil may be used.

It is a block diagram of an ejector cycle provided with the gas-liquid separator which concerns on one Embodiment of this invention. It is sectional drawing of the gas-liquid separator of FIG. It is a schematic diagram with which it uses for description of an effect | action of the gas-liquid separator of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... High pressure side heat exchanger, 3 ... Low pressure side heat exchanger, 4 ... Ejector, 5 ... Gas-liquid separator, 56 ... Coarse grain member.

Claims (4)

A compressor (1) for increasing the pressure of refrigerant mixed with refrigerating machine oil;
A high-pressure side heat exchanger (2) for cooling the high-pressure refrigerant flowing out of the compressor (1);
A low pressure side heat exchanger (3) for evaporating the low pressure refrigerant;
An ejector (4) for decompressing and expanding the refrigerant that has flowed out of the high-pressure side heat exchanger (2) and increasing the pressure by mixing the decompressed and expanded refrigerant and the refrigerant sucked from the low-pressure side heat exchanger (3); Applied to ejector cycle with
It said ejector (4) the refrigerant flow out to separate into a gas phase refrigerant and liquid-phase refrigerant from supplying the gas refrigerant to the suction side of the compressor (1), the low-pressure side heat exchanger the liquid refrigerant A gas-liquid separator (5) to be supplied to the vessel (3),
An inlet (52) through which the refrigerant flowing out from the ejector (4) flows, a gas phase refrigerant outlet (53) through which the gas phase refrigerant flows out, a liquid phase refrigerant outlet (54) through which the liquid phase refrigerant flows out, And an oil return port (55) through which the refrigerator oil flows out,
The inlet (52) and the gas-phase refrigerant outlet (53) are located above the liquid-phase refrigerant outlet (54) and the oil return port (55),
And a coarsening member (56) for increasing the particle size of the refrigerating machine oil before passing through when the liquid-phase refrigerant passes through ,
The coarse member (56) is between the inlet (52) and the gas-phase refrigerant outlet (53), and between the liquid-phase refrigerant outlet (54) and the oil return port (55). And the gas-liquid separator for ejector cycles is arrange | positioned below the liquid level of the mixed phase fluid of the said liquid phase refrigerant | coolant and the said refrigerator oil .   The gas-liquid separator for an ejector cycle according to claim 1, wherein the coarsening member (56) is a fibrous member.   The gas-liquid separator for an ejector cycle according to claim 1, wherein the coarse member (56) is a porous member. Gas ejector cycle according to any one of claims 1 to 3, wherein are positioned with al above the previous SL liquid refrigerant outlet (54) the oil return openings (55) Liquid separator.

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