U.S. patent application number 11/821879 was filed with the patent office on 2008-01-03 for distributor of a gas-liquid two phase fluid.
This patent application is currently assigned to DENSO Corporation. Invention is credited to Ryoko Fujiwara, Hideya Matsui, Haruyuki Nishijima, Gentarou Oomura, Hirotsugu Takeuchi, Etsuhisa Yamada.
Application Number | 20080000263 11/821879 |
Document ID | / |
Family ID | 38777177 |
Filed Date | 2008-01-03 |
United States Patent
Application |
20080000263 |
Kind Code |
A1 |
Oomura; Gentarou ; et
al. |
January 3, 2008 |
Distributor of a gas-liquid two phase fluid
Abstract
A distributor able to evenly supply influent two-phase
refrigerant flowing in by various flow states to different pipes
with an extremely small pressure loss, that is, a distributor of a
gas-liquid two-phase fluid distributing a gas-liquid two-phase
fluid flowing in from an inlet pipe into a plurality of
distribution pipes, provided with a cylindrical vessel with a
cylindrical upper part, an inlet pipe connected in a tangential
direction with respect to a circular cross section of the upper
portion of the cylindrical vessel, and distribution pipes connected
to a lower portion of the cylindrical vessel.
Inventors: |
Oomura; Gentarou; (Obu-city,
JP) ; Nishijima; Haruyuki; (Obu-city, JP) ;
Yamada; Etsuhisa; (Kariya-city, JP) ; Takeuchi;
Hirotsugu; (Nagoya-city, JP) ; Matsui; Hideya;
(Kariya-city, JP) ; Fujiwara; Ryoko; (Kariya-city,
JP) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Assignee: |
DENSO Corporation
Kariya-city
JP
|
Family ID: |
38777177 |
Appl. No.: |
11/821879 |
Filed: |
June 26, 2007 |
Current U.S.
Class: |
62/525 |
Current CPC
Class: |
F25B 39/028 20130101;
F25B 41/45 20210101; F25B 2400/23 20130101; F25B 2400/02 20130101;
F25B 2341/0012 20130101 |
Class at
Publication: |
62/525 |
International
Class: |
F25B 39/02 20060101
F25B039/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 30, 2006 |
JP |
2006-182386 |
Claims
1. A distributor of a gas-liquid two-phase fluid distributing a
gas-liquid two-phase fluid flowing in from an inlet pipe into a
plurality of distribution pipes, provided with a cylindrical vessel
with a cylindrical upper part, an inlet pipe connected in a
tangential direction with respect to a circular cross section of
the upper portion of the cylindrical vessel, and distribution pipes
connected to a lower portion of the cylindrical vessel.
2. A distributor according to claim 1 wherein the lower portion of
the cylindrical vessel is formed into a reverse conical shape.
3. A distributor according to claim 1 wherein said inlet pipe is
curved just before being connected to said cylindrical vessel.
4. A refrigeration cycle provided with a distributor according to
claim 1 downstream of an ejector.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a distributor provided in a
refrigerant circuit of an air conditioning system or the like and
distributing a two-phase refrigerant to a plurality of heat
exchangers and the like, more particularly relates to structure
uniformly dividing a two-phase refrigerant of a uniform mixing
ratio.
[0003] 2. Description of the Related Art
[0004] In the past, as shown in FIG. 4, there has been proposed a
refrigeration cycle 100 connecting a refrigerant compressor 102,
refrigerant condenser 103, ejector 104, first refrigerant
evaporator 113 of an indoor heat exchanger 105, and a gas-liquid
separator 106 successively in a ring by refrigerant piping 107 and
connecting a liquid phase refrigerant side of the gas-liquid
separator 106 and a suction part 108 of the ejector 104 by bypass
piping 109 provided with a second refrigerant evaporator 114 of the
indoor heat exchanger 105 (Japanese Patent No. 3265649).
[0005] Here, the ejector 4, as shown in FIG. 5, is attached to the
side surface of the indoor heat exchanger 105. The ejector 4, as
shown in FIG. 6, ejects a liquid phase refrigerant condensed and
liquefied by the refrigerant condenser 103, whereby the gas phase
refrigerant is sucked in by the suction part 108, the liquid phase
refrigerant and gas phase refrigerant are mixed and raised in
pressure in a diffuser 111, then the refrigerant of the gas-liquid
two-phase state (below, referred to as "two-phase refrigerant") is
sent via a distributor 112 to a first refrigerant evaporator 113.
The distributor 112, as shown in FIGS. 1 and 2, is a pipe evenly
distributing the refrigerant of the gas-liquid two-phase state
flowing out from the ejector 104 to the plurality of tubes of the
first refrigerant evaporator 113.
[0006] The role of the distributor 112 is to evenly supply
two-phase refrigerant flowing in by various flow states (slag flow,
mist flow, annular flow, and the like) to the pipes. However, the
refrigerant ejected by the nozzle 110 flows affected by the
gas-liquid ratio and flow rate. Refrigerant with a large liquid
phase runs through the lower distribution pipe 112a due to the
effect of gravity, while refrigerant with a large gas phase runs
through the upper distribution pipe 112b. Due to this, the
distributor 112 cannot completely fulfill its role.
[0007] Further, pressure loss occurs downstream of the ejector, the
pressure boosting effect by the ejector is diminished.
Consequently, pressure loss downstream of the ejector should be
avoided as much as possible. Despite this, since the refrigerant
directly flows from the diffuser 111 to the distribution pipe 112,
it changes to a direction in which the channel cross-sectional area
is greatly reduced. Due to this throttling effect, pressure loss
occurs. Note that, as widely known, in an expansion valve cycle,
compared with the ejector cycle, the amount of pressure loss at the
distributor portion is adjusted by the amount of throttling of the
expansion valve, so the effect of the pressure loss is small.
[0008] On the other hand, as distributors of two-phase
refrigerants, there are the ones disclosed in Japanese Patent
Publication (A) No. 6-201225 and No. 5-340648, but these had energy
loss since they lifted the liquid upward for transport after
gas-liquid separation. Further, these required a downstream side
circular upper surface having a diameter larger than the diameter
of the swirl part and gently inclined conical surface for holding
the liquid film, so became extremely large impractical vessels.
Both were imperfect for performing their functions.
SUMMARY OF THE INVENTION
[0009] An object of the present invention is to provide a
distributor that can evenly supply two-phase refrigerant flowing in
by various flow states to the pipes without pressure loss.
[0010] The present invention provides a distributor of a gas-liquid
two-phase fluid according to the claims as a means of achieving the
object.
[0011] According to a first aspect of the invention, there is
provided a distributor of a gas-liquid two-phase fluid provided
with a cylindrical vessel with a cylindrical upper part, an inlet
pipe connected in a tangential direction with respect to a circular
cross section of the upper portion of the cylindrical vessel, and
distribution pipes connected to a lower portion of the cylindrical
vessel.
[0012] Since the inlet pipe is connected in a tangential direction
with respect to the circular cross section of the cylindrical
vessel, the two-phase fluid is separated into a gas phase and a
liquid phase in the cylindrical vessel irrespective of the form of
the inlet flow by a known centrifugal separation action. The liquid
phase forms a thin liquid film at the inner surface of the
cylindrical vessel and drips down by gravity and forms a uniform
liquid film thickness along with the action of the refrigerant
swirl flow. The liquid film formed in the uniform thickness flows
downward while swirling and reaches the plurality of distribution
pipes arranged at the lower portion of the cylindrical vessel. In
the distribution pipes, the liquid film formed in the uniform
thickness and the gas phase refrigerant flow in, so a two-phase
fluid comprised of a gas and liquid evenly mixed is formed and
flows. Further, the two-phase fluid moves inside the vessel by
gravity, so the energy loss (pressure loss) is extremely small.
[0013] According to a second aspect of the invention, the
distributor of a gas-liquid two-phase fluid is one where the lower
portion of the cylindrical vessel is formed into a reverse conical
shape. The two-phase fluid forms a swirl flow along the inner
surface of the vessel and flows toward the lower part of the vessel
by gravity. At this time, the liquid film on the reverse conical
surface occurring due to the centrifugal separation action is
subjected to an upward force component due to the reverse conical
surface with respect to this centrifugal force, so the dropping
speed is eased. Further, due to the reverse conical surface, the
angular speed .omega. rises, the centrifugal force mr.omega..sup.2
becomes larger, and the centrifugal separation action is promoted
(since the peripheral speed is substantially fixed, by the amount
by which the radius r becomes smaller). Because of this, the liquid
film of a more uniform thickness drops down while swirling on the
reverse conical surface.
[0014] According to a third aspect of the invention, there is
provided a distributor of the first aspect wherein said inlet pipe
is curved just before being connected to said cylindrical vessel.
This curved portion has the function of causing a centrifugal
separation action, so the cylindrical vessel generating the
centrifugal separation action can be made smaller.
[0015] According to a fourth aspect of the invention, there is
provided a refrigeration cycle provided with any of the above
distributors downstream of an ejector.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] These and other objects and features of the present
invention will become clearer from the following description of the
preferred embodiments given with reference to the attached
drawings, wherein:
[0017] FIG. 1 shows a first embodiment of a distributor according
to the present invention by schematic views,
[0018] FIG. 2 shows a first embodiment of a distributor according
to the present invention by a schematic view,
[0019] FIG. 3 shows a first embodiment of a distributor according
to the present invention by a schematic view,
[0020] FIG. 4 shows a conventional refrigeration cycle provided
with an ejector,
[0021] FIG. 5 is the perspective view of an indoor heat exchanger
forming part of the cycle of FIG. 4, and
[0022] FIG. 6 shows an ejector and distributor forming parts of the
cycle of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Preferred embodiments of the present invention will be
described in detail below while referring to the attached
figures.
First Embodiment
[0024] FIG. 1 shows a first embodiment of a distributor according
to the present invention by schematic views. FIG. 1(a) shows a top
view of the distributor, while FIG. 1(b) shows a side
cross-sectional view of the distributor. In FIG. 1, reference
numeral 10 is a distributor of the first embodiment, 1 is a
cylindrical vessel, 2 is an inlet pipe, and 3 are distribution
pipes.
[0025] The inlet pipe 2 is connected in a tangential direction with
respect to the circular cross-section of the upper portion of the
cylindrical vessel 1. At the lower portion of the cylindrical
vessel 1, a plurality of distribution pipes 3 are connected at
positions separated by equal angles in the peripheral direction and
extend outward radially. That is, the plurality of distribution
pipes 3 are connected to the cylindrical vessel 1 so that the
intervals between them become equal distances.
[0026] Further, the gas phase two-phase refrigerant (for example,
having a ratio of the liquid phase to the gas phase of
approximately 0.3 vol %) flows from the inlet pipe 2 into the
cylindrical vessel 1 from a tangential direction at the peripheral
part and separates into gas and liquid by the centrifugal force
acting on this in the process of swirling inside the cylindrical
vessel 1. The heavy liquid collects at the peripheral side, while
the light gas collects at the center. The gas becomes a uniform
pressure and flows from an outlet 3a to the distribution pipes 3 in
the process of moving while swirling.
[0027] On the other hand, the liquid swirls along the inner surface
of the cylindrical wall 1a and free falls by gravity, swirls, and
forms a liquid film. As it proceeds, the thickness of the liquid
film becomes a uniform thickness over the entire circumference due
to the action of the surface tension and flows into the
distribution pipes 3. Note that when the volume ratio of the liquid
phase is 0.3 vol %, the liquid film thickness is approximately 0.1
mm. The liquid free falls, so can move downward with no energy
loss.
[0028] In this way, near the distribution pipes 3, the liquid
becomes a film of a uniform thickness over the entire circumference
and the gas becomes a uniform pressure over the entire
circumference when flowing into the distribution pipes 3. Therefore
so the gas phase two-phase refrigerant can be evenly dispensed.
Conversely, if making the intervals of the mounting positions of
the distribution pipes 3 unequal, it is possible to change the
ratio of distribution to the distribution pipes 3.
Second Embodiment
[0029] FIG. 2 shows the side cross-section of a second embodiment
of the distributor according to the present invention by a
schematic view. The top view is the same as FIG. 1 (a), so is
omitted. The distributor of the second embodiment differs from the
first embodiment in only the cylindrical vessel. Therefore, parts
substantively the same as the parts of the first embodiment are
assigned the same reference notations and explanations are
omitted.
[0030] In FIG. 2, reference numeral 20 is the distributor of the
second embodiment, while 21 is a vessel with a cylindrical upper
portion 21b and an inverted conical lower portion 21c (below
referred to as "the upper portion cylindrical vessel").
[0031] The two-phase refrigerant forms a swirl flow along the inner
surface 21a of the vessel 21 and flows toward the bottom of the
vessel 21. At that time, the liquid film on the reverse conical
surface generated by the centrifugal separation action is subjected
to an upward force component by the reverse conical surface 21c
with respect to this centrifugal force, so the dropping speed is
eased. Further, due to the reverse conical surface, the angular
speed .omega. rises and the centrifugal separation action is
promoted. Because of this, the liquid film of a more uniform
thickness drops down while swirling on the reverse conical
surface.
[0032] Note that the diameter D2 of the circular cross-section near
the cut apex of the cone (that is, near the distribution pipe
connection portion) is preferably larger than the inlet pipe inside
diameter D1. This is to avoid a pressure loss by the throttling
effect. Further, the tilt angle of the cone can be set to an
optimal value by parameters such as the flow rate at the vessel
inlet, dryness of the refrigerant, D1, D2, and the like.
[0033] In this way, near the distribution pipes 3, the liquid forms
a film of a more uniform thickness over the entire circumference,
while the gas becomes a uniform pressure over the entire
circumference when flowing into the distribution pipes 3. Therefore
so the gas phase two-phase refrigerant can be evenly dispensed.
Third Embodiment
[0034] FIG. 3 shows a top view of a third embodiment of a
distributor according to the present invention by schematic view.
The side cross-sectional view is the same as FIG. 1(b), so is
omitted. The distributor of the third embodiment differs from the
first embodiment in only the inlet pipe is different. Therefore,
parts substantively the same as the parts of the first embodiment
are assigned the same reference notations and explanations are
omitted.
[0035] In FIG. 2, reference numeral 30 is the distributor of the
third embodiment, while 32 is the inlet pipe. The inlet pipe 32 has
a curved portion 32a that curves just before being connected to the
cylindrical vessel 1. This curve portion 32a has the function of
generating a centrifugal separation action, so it becomes possible
to make cylindrical vessel 1 smaller by that amount.
[0036] While the invention has been described with reference to
specific embodiments chosen for purpose of illustration, it should
be apparent that numerous modifications could be made thereto by
those skilled in the art without departing from the basic concept
and scope of the invention.
* * * * *