JP4609388B2 - Gas-liquid two-phase fluid distributor - Google Patents

Description

  The present invention relates to a distributor that is disposed in a refrigerant circuit such as an air conditioner and distributes a two-phase refrigerant to a plurality of heat exchangers, and more particularly to a structure that equally divides a two-phase refrigerant having a uniform mixing ratio. .

  Conventionally, as shown in FIG. 4, the refrigerant compressor 102, the refrigerant condenser 103, the ejector 104, the first refrigerant evaporator 113 and the gas-liquid separator 106 of the indoor heat exchanger 105 are sequentially connected in an annular manner by a refrigerant pipe 107. In addition, the refrigeration cycle 100 in which the liquid-phase refrigerant side of the gas-liquid separator 106 and the suction part 108 of the ejector 104 are connected by a bypass pipe 109 in which the second refrigerant evaporator 114 of the indoor heat exchanger 105 is arranged. Has been proposed (Patent Document 1).

Here, the ejector 4 is attached to the side surface of the indoor heat exchanger 105 as shown in FIG. As shown in FIG. 6, the ejector 4 sucks the gas-phase refrigerant from the suction unit 108 by ejecting the liquid-phase refrigerant condensed and liquefied by the refrigerant condenser 103 from the nozzle 110, and the liquid-phase refrigerant in the diffuser 111. after boosting with mixed refrigerant and gas-phase refrigerant, a first refrigerant evaporator 1 13 to the gas-liquid two-phase state refrigerant (hereinafter, referred to as "two-phase refrigerant") via the distributor 112 to be described later to send those It is. As shown in FIG. 12, the distributor 112 is a pipe that evenly distributes the gas-liquid two-phase refrigerant flowing out from the ejector 104 to each of the plurality of tubes of the first refrigerant evaporator 113.

  The role of the distributor 112 is to uniformly supply the two-phase refrigerant flowing in various flow states (slag flow, mist flow, annular flow, etc.) to each pipe. However, depending on the gas-liquid ratio and flow velocity, the refrigerant ejected from the nozzle 110 passes through the lower distribution pipe 112a through the lower distribution pipe 112a due to the influence of gravity, and the upper distribution pipe 112b has a larger gas phase. The refrigerant passes through. As a result, the distributor 112 did not fully fulfill its role.

Further, when a pressure loss occurs downstream of the ejector, the pressure increasing effect by the ejector is diminished. For this reason, pressure loss downstream of the ejector should be avoided as much as possible. Nevertheless, since it flows directly from the diffuser 111 to the distribution pipe 112, the flow passage cross-sectional area changes in a direction that is greatly reduced, and pressure loss occurs due to this restriction effect. As is well known, the expansion valve cycle is less affected by the pressure loss than the ejector cycle because the pressure loss in the distributor is adjusted by the throttle amount of the expansion valve.
On the other hand, there are two-phase refrigerant distributors disclosed in Patent Documents 2 and 3. However, after separating the gas and liquid, the liquid is lifted and conveyed, resulting in energy loss. In addition, these require a circular upper surface on the downstream side having a diameter larger than the diameter of the swivel part, and a gently inclined circular surface for holding the liquid film, which makes the container extremely large and impractical. It was incomplete to fulfill.

Japanese Patent No. 3265649 JP-A-6-201225 JP-A-5-340648

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a distributor that can evenly supply two-phase refrigerant flowing in various flow modes to each pipe without pressure loss. That is.

The present invention provides a gas-liquid two-phase fluid distributor according to each of the claims as means for solving the problems.
According to the first aspect of the present invention, the gas-liquid two-phase fluid distributor is connected in a tangential direction to a cylindrical container having a cylindrical upper part and a circular cross section of the upper part of the cylindrical container. An inlet pipe, and an end of the distribution pipe connected to a lower side wall of the cylindrical container, and a distribution pipe extending radially outward with respect to the circular cross section of the lower part of the cylindrical container ; It is characterized by providing.

  Since the inlet tube is connected tangentially to the circular cross section of the cylindrical vessel, the two-phase fluid is separated into the gas phase and the liquid phase in the cylindrical vessel by a well-known centrifugal action regardless of the inlet flow mode. Is done. In the liquid phase, a thin liquid film is formed on the inner surface of the cylindrical container, and dropping by the gravity and the action of the refrigerant swirl flow combine to form a uniform liquid film thickness. The liquid film having a uniform thickness flows downward while swirling and reaches a plurality of distribution pipes arranged at the lower part of the cylindrical container. In this distribution pipe, a liquid film and a gas phase refrigerant having a uniform thickness flow in, so that a two-phase fluid in which gas and liquid are evenly mixed is formed and flows. And since a two-phase fluid moves by the gravity in a container, an energy loss (pressure loss) is very small.

According to a second aspect of the present invention, the gas-liquid two-phase fluid distributor is characterized in that the lower portion of the cylindrical container is formed in an inverted conical shape. The two-phase fluid forms a swirling flow along the inner surface of the container and flows toward the bottom of the container due to gravity. Since the upward component force acts, the fall speed is reduced. Further, the angular velocity ω is increased by the inverted conical surface (the radius r is decreased because the peripheral speed is substantially constant), the centrifugal force mrω ² is increased, and the centrifugal separation action is promoted. Therefore, the liquid film having a more uniform thickness falls while turning on the inverted conical surface.

  According to a third aspect of the present invention, the gas-liquid two-phase fluid distributor is characterized in that the inlet pipe is curved immediately before being connected to the cylindrical container. Since the curved portion has a function of generating a centrifugal separation action, it is possible to reduce the cylindrical container that generates the centrifugal separation action accordingly.

  According to the invention described in claim 4, the refrigeration cycle includes the distributor according to any one of claims 1 to 3 downstream of the ejector.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 schematically shows a first embodiment of a distributor according to the present invention. FIG. 1A is a top view of the distributor, and FIG. 1B is a side sectional view of the distributor. Represents. In FIG. 1, reference numeral 10 denotes a distributor according to the first embodiment, 1 denotes a cylindrical container, 2 denotes an inlet pipe, and 3 denotes a distribution pipe.

  The inlet pipe 2 is connected in a tangential direction with respect to the circular cross section of the upper part of the cylindrical container 1. At the lower part of the cylindrical container 1, a plurality of distribution pipes 3 are connected to positions divided at equal angles in the circumferential direction and extend in the radial direction. That is, the plurality of distribution pipes 3 are connected to the cylindrical container 1 so that the distance between them is an equal distance.

  A gas-liquid two-phase refrigerant (for example, the ratio of the liquid phase to the gas phase is about 0.3% by volume) flows into the cylindrical container 1 from the inlet pipe 2 from the tangential direction of the outer periphery thereof, and the cylindrical container 1 The gas a and the liquid b are separated by the centrifugal force acting on this in the process of turning inside, the heavy liquid b gathers at the outer peripheral side, and the light gas a gathers at the center. The gas a becomes a uniform pressure in the process of moving while swirling, and flows into the distribution pipe 3 from the outlet 3a.

  On the other hand, the liquid b swirls along the inner surface of the cylindrical wall 1a and freely falls by its gravity, forms a liquid film while swirling, and the thickness of the liquid film over the entire circumference by the surface tension action as it advances. A uniform thickness flows into each distribution pipe 3. When the liquid phase volume ratio is 0.3% by volume, the liquid film thickness is about 0.1 mm. The liquid b is free to fall and has no energy loss, and can move downward.

  Thus, in the vicinity of the distribution pipe 3, the liquid b becomes a thin film having a uniform thickness over the entire circumference, and the gas a flows into the distribution pipe 3 with a uniform pressure over the entire circumference. Are distributed equally. On the contrary, if the intervals between the mounting positions of the distribution pipes 3 are unequal, the distribution ratio to each distribution pipe 3 can be changed.

(Second Embodiment)
FIG. 2 is a schematic side view of a second embodiment of the distributor according to the present invention. The top view is the same as FIG. The distributor of the second embodiment is different from the first embodiment only in the cylindrical container. Therefore, about the substantially same part in the part of 1st Embodiment, the description is abbreviate | omitted by attaching | subjecting the same referential mark.

  In FIG. 2, reference numeral 20 denotes a distributor according to the second embodiment, and 21 denotes a container having an upper part 21 b in a cylindrical shape and a lower part 21 c in an inverted conical shape (hereinafter referred to as “upper cylindrical container”).

  When the two-phase refrigerant flows toward the lower side of the container 21 while forming a swirling flow along the inner surface 21a of the container 21, the liquid film on the reverse conical surface generated by the centrifugal separation is opposite to the centrifugal force. Since the upward component force acts by the conical surface 21c, the falling speed is reduced. Furthermore, the angular velocity ω is increased by the inverted conical surface, and the centrifugal separation action is promoted. Therefore, a liquid film having a more uniform thickness turns and falls on the inverted conical surface.

  In addition, it is preferable that the diameter D2 of the circular cross section near the cutting top of the cone (that is, near the distribution pipe connecting portion) is larger than the inlet pipe inner diameter D1. This is to avoid pressure loss due to the throttling effect. The cone inclination angle is set to an optimum value according to parameters such as the flow velocity at the container inlet, the dryness of the refrigerant, and D1 and D2.

  Thus, in the vicinity of the distribution pipe 3, the liquid b becomes a thin film having a more uniform thickness over the entire circumference, and the gas a flows into the distribution pipe 3 with a uniform pressure over the entire circumference. The liquid two-phase refrigerant is distributed more evenly.

(Third embodiment)
FIG. 3 is a schematic diagram showing a top view of a third embodiment of the distributor according to the present invention. The side sectional view is the same as FIG. The distributor of the third embodiment is different from the first embodiment only in the inlet pipe. Therefore, about the substantially same part in the part of 1st Embodiment, the description is abbreviate | omitted by attaching | subjecting the same referential mark.

  In FIG. 2, reference numeral 30 denotes a distributor according to the third embodiment, and 32 denotes an inlet pipe. The inlet pipe 32 has a curved portion 32 a that is curved immediately before being connected to the cylindrical container 1. Since the curved portion 32a has a function of generating a centrifugal separation action, the cylindrical container 1 can be made smaller accordingly.

1 is a schematic view of a first embodiment of a distributor according to the present invention. FIG. 2 is a schematic diagram showing a second embodiment of a distributor according to the present invention. FIG. 3 schematically shows a third embodiment of a distributor according to the present invention. It is the refrigerating cycle provided with the conventional ejector. It is a perspective view of the indoor heat exchanger which comprises the cycle of FIG. It is the ejector and distributor which comprise the cycle of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylindrical container 2 Inlet pipe 3 Distribution pipe 10 Distributor of 1st Embodiment

Claims (4)

A gas-liquid two-phase fluid distributor that distributes a gas-liquid two-phase fluid flowing from an inlet pipe (2, 32) to a plurality of distribution pipes (3),
A cylindrical container (1, 21) whose upper part is cylindrical,
The inlet pipe (2, 32) connected tangentially to the circular cross section of the upper part of the cylindrical container;
An end of the distribution pipe (3) is connected to the lower side wall of the cylindrical container, and the distribution pipe (3) extends radially outward with respect to the circular cross section of the lower part of the cylindrical container. When,
A gas-liquid two-phase fluid distributor (10, 20, 30) characterized by comprising:   The distributor (20) according to claim 1, wherein the lower part (21c) of the cylindrical container (21) is formed in an inverted conical shape.   3. Distributor according to claim 1 or 2, characterized in that the inlet pipe (32) is curved just before being connected to the cylindrical container (1, 21).   A refrigeration cycle comprising the distributor according to any one of claims 1 to 3 downstream of the ejector.

Images