U.S. patent number 3,590,592 [Application Number 04/835,474] was granted by the patent office on 1971-07-06 for refrigerant system expansion means.
This patent grant is currently assigned to Carrier Corporation. Invention is credited to Charles N. High.
United States Patent |
3,590,592 |
High |
July 6, 1971 |
REFRIGERANT SYSTEM EXPANSION MEANS
Abstract
A refrigerant expansion or metering device employed in
refrigeration systems including compression means, a first heat
exchanger and a second heat exchanger, comprising a fluid regulator
forming a vortex chamber, through which refrigerant is passed.
Disposed within the vortex chamber is movable means operable to
vary the path of flow and to vary the rate of flow of refrigerant
through the vortex chamber. Control means vary the position of the
movable means in response to changes in temperature in the
refrigeration system.
Inventors: |
High; Charles N. (Syracuse,
NY) |
Assignee: |
Carrier Corporation, (Syracuse,
NY)
|
Family
ID: |
25269588 |
Appl.
No.: |
04/835,474 |
Filed: |
June 23, 1969 |
Current U.S.
Class: |
62/115;
62/225 |
Current CPC
Class: |
F25B
41/30 (20210101) |
Current International
Class: |
F25B
41/06 (20060101); F25b 041/04 () |
Field of
Search: |
;137/81.5
;62/225,160,197,471,500 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Perlin; Meyer
Claims
I claim:
1. A refrigeration system comprising compression means, a first
heat exchanger for receiving refrigerant discharged by said
compression means; refrigerant metering means connected with said
first heat exchanger; and a second heat exchanger arranged between
said refrigerant metering means and said compression means, said
components being connected to form a refrigerant flow cycle, said
refrigerant metering means including:
A. a fluid regulator forming a vortex chamber through which
refrigerant passes en route to said second heat exchanger, said
vortex chamber having plunger means movably disposed therein;
and
B. control means to vary the position of said plunger means in said
vortex chamber, in response to the temperature of refrigerant
exiting from said second heat exchanger, to vary the path of flow
and to vary the rate of flow of said refrigerant through said
vortex chamber in accordance with changes in system cooling
load.
2. A refrigeration system in accordance with claim 1 wherein said
control means includes:
A. a bellows having a refrigerant charge contained therein operably
connected to said plunger means; and
B. means operable to sense the temperature of said refrigerant
leaving said second heat exchanger, said means being further
operable to increase the pressure of said refrigerant charge in
said bellows as the temperature of the refrigerant leaving the
second heat exchanger increases to move said plunger means further
into said vortex chamber and to decrease the pressure of said
refrigerant charge in said bellows as the temperature of the
refrigerant leaving the second heat exchanger decreases to withdraw
said plunger means from said vortex chamber.
3. A refrigerant-metering device employed in refrigeration systems
operable to expand relatively high-pressure liquid refrigerant
comprising:
A. a fluid regulator forming a vortex chamber through which
refrigerant is passed;
B. refrigerant inlet means into said vortex chamber;
C. refrigerant outlet means from said vortex chamber;
D. plunger means movably disposed in said vortex chamber to vary
the flow path of refrigerant therethrough; and
E. control means operable to vary the position of said plunger
means in said vortex chamber in response to predetermined
refrigeration system conditions, to vary the path of flow and to
vary the rate of flow of said refrigerant through said vortex
chamber in accordance with changes in said system conditions.
4. A refrigerant metering device in accordance with claim 3 wherein
said refrigerant inlet means is in substantially tangential
communication with said vortex chamber.
5. A refrigerant metering device in accordance with claim 3 wherein
said refrigerant passing through said vortex chamber undergoes an
approximate 90.degree. change in direction from entering said
chamber at said inlet means to leaving said chamber at said outlet
means.
6. A refrigerant-metering device in accordance with claim 3 wherein
said control means include:
A. a bellows having a refrigerant charge contained therein,
operably connected to said plunger means; and
B. means operable to sense the temperature of refrigerant in one
portion of said refrigeration system, said means being further
operable to increase the pressure of said refrigerant charge in
said bellows as the temperature of the sensed refrigerant
increases, to move said plunger means further into said vortex
chamber; and to decrease the pressure of said refrigerant charge in
said bellows as the sensed refrigerant temperature decreases to
withdraw said plunger means from said vortex chamber.
7. A method of regulating the flow of refrigerant in a
refrigeration system comprising compression means, a first heat
exchanger and a second heat exchanger comprising the steps of:
A. energizing said compression means to circulate said refrigerant
through said system;
B. directing the flow of refrigerant from the first heat exchanger
to the second heat exchanger through a path including a vortex;
C. withdrawing mechanical flow obstruction means, disposed within
said vortex in the path of refrigerant flow, to restrict the flow
of refrigerant from the first heat exchanger to said second heat
exchanger as the cooling load on said system increases; and
D. projecting said mechanical obstruction means, disposed within
said vortex chamber in the path of refrigerant flow, to increase
the flow of refrigerant from the first heat exchanger to said
second heat exchanger as the cooling load on said system increases.
Description
BACKGROUND OF THE INVENTION
This invention relates to refrigeration systems and more
particularly, to an improved expansion means for refrigeration
systems.
Refrigeration systems employ, as a means for expanding the
relatively high-pressure liquid refrigerant leaving the system
condenser, either a fixed restrictor, commonly known as a capillary
tube, or a variable restrictor, such as a thermal expansion valve.
While fixed restrictors are relatively inexpensive, their lack of
adaptability to change in system load limits their usefulness. On
the other hand, the variable restrictor, such as a thermal
expansion valve, incorporates a controlling mechanism for varying
the valve setting in response to changes in refrigerant temperature
exiting from the evaporator due to variations in load conditions in
the system. However, variable restrictors are relatively expensive
and are generally the subject of numerous repairs.
The invention herein disclosed relates to a novel expansion device,
one that is relatively inexpensive to manufacture and relatively
maintenance free, and one that is adaptable to changes of
temperature of the refrigerant exiting from the evaporator.
SUMMARY OF THE INVENTION
The invention herein disclosed may be employed in a refrigeration
system including compression means, a first heat exchanger for
receiving refrigerant discharged by the compression means, and a
second heat exchanger connected to the suction side of the
compression means. The invention herein disclosed communicates the
first heat exchanger with the second heat exchanger. Relatively
high-pressure liquid refrigerant flows from the first heat
exchanger through the invention functioning as the system
refrigerant expansion device. The refrigerant leaves the invention
as a relatively low-pressure mixture of liquid and gas.
The refrigerant expansion device includes a fluid regulator forming
a vortex chamber through which the refrigerant passes en route to
the second heat exchanger. The refrigerant inlet in the chamber is
in substantially tangential communication therewith. The
refrigerant passing through the chamber undergoes an approximate
90.degree. change in direction.
Disposed in the chamber, transverse to the path of flow of the
refrigerant, is a movable means, such as a plunger. Control means,
operable to selectively withdraw the movable means from the chamber
or project the movable means further into the chamber, functions in
accordance with changes in the temperature of the refrigerant
exiting from the second heat exchanger. When the plunger is
substantially withdrawn from the chamber, the vortex effect on the
refrigerant flow is at its maximum, the refrigerant flow through
the chamber being greatly impeded. As the plunger is projected in
the chamber, the vortex effect is reduced, the refrigerant flow
through the chamber being thereby increased.
BRIEF DESCRIPTION OF THE DRAWING
The single FIGURE of the drawing is a schematic view, partially in
section, of a refrigeration system incorporating the novel
refrigeration expansion means.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the single FIGURE of the drawing, there is shown a
refrigeration system 10 employing the novel refrigeration expansion
device 15 herein disclosed. The refrigeration system 10 is typical
of the type used with air-conditioning units, such as a room air
conditioner. Refrigeration system 10 has a suitable refrigerant
compressor 11 which, while illustrated as a reciprocating
compressor, may comprise any suitable compressor such as a rotary,
centrifugal, etc. Refrigerant line 12 conducts the relatively
high-pressure gaseous refrigerant discharged from compressor 11 to
a first heat exchanger 13, functioning as the system condenser.
The high-pressure, gaseous refrigerant condenses in the first heat
exchanger 13 by therethrough in heat transfer relationship with a
relatively cold medium such as air. The liquid refrigerant formed
thereby passes to the system expansion or metering means 15 via
conduit 14.
Expansion device 15 reduces the pressure of the liquid refrigerant
and controls the flow thereof to the remaining portion of the
system. A detailed discussion of the novel expansion device 15 will
be found hereinafter.
The reduced pressure liquid refrigerant is fed via line 16 to a
second heat exchanger 17 functioning as the system evaporator. The
thermal interchange effected by evaporator 17 between the
refrigerant and the medium being cooled, for example air, vaporizes
or evaporates refrigerant while extracting heat from the medium
being cooled. A suitable circulating means such as a fan (not
shown) may be provided for bringing the medium being cooled into
heat transfer relation with the refrigerant in the evaporator 17.
Vaporized refrigerant leaving evaporator 17 returns through line 18
to the inlet or suction side of the compressor 11.
The refrigerant expansion or metering means 15 disclosed herein is
a vortex-type fluid regulator. The regulator comprises a shell 19
forming a generally cylindrical vortex chamber 20. Refrigerant line
14, which connects to inlet 21 in the peripheral wall of shell 19,
discharges during system operation a stream of liquid refrigerant
into vortex chamber 20. Inlet 21 is in substantially tangential
communication with chamber 20. Outlet 22 in end wall 23 of the
regulator communicates with refrigerant line 16. As is manifest,
refrigerant entering vortex chamber 20 undergoes an approximate
90.degree. change in direction for discharge through outlet 22 into
line 16.
Movably disposed in the chamber 20, transverse to the flow path of
the refrigerant, is obstruction means 24 such as a rod or plunger.
The purpose of obstruction means 24 is to vary the vortex effect
created in chamber 20 and hence vary the discharge of refrigerant
to line 16, thence to evaporator 17. Control means associated with
movable obstruction means 24 acts to selectively withdraw or
project the movable means 24 from or into chamber 20 in response to
changes in temperatures of the refrigerant exiting from the
evaporator 17. As movable means 24 is projected further into
chamber 20, the vortex effect on the refrigerant flow is lessened;
movable obstruction means 24 reduces the restrictive effect of a
vortex flow path. Conversely, the further movable means is
withdrawn from chamber 20, the greater is the vortex effect on the
refrigerant flow. Thus, at peak cooling loads, it is desirable for
obstruction means 24 to extend fully into chamber 20, while at
minimal cooling loads on the system, it is desirable for the means
24 to be substantially completely withdrawn from the chamber 20 and
thus the refrigerant flow therethrough is greatly impeded as
desired.
The control means employed with the preferred embodiment of the
novel refrigerant expansion device includes an expandable bellows
25 connected to movable means 24. The bellows 25 is disposed in a
housing 30, preferably formed integrally with shell 19. The inner
surface of the wall of the bellows 25 defines a chamber 28
containing a charge of refrigerant, such as R-22. The outer surface
of the wall of the bellows 25 and the inner surface of the housing
30 define a chamber 31. Obstruction means 24 movably disposed
within chamber 31 extends therefrom into chamber 20 via passageway
29 formed in the wall of shell 19. Sealing means 34 is employed to
prevent an appreciable quantity of refrigerant from flowing to
chamber 31 from chamber 20.
Communicating refrigerant line 16 to chamber 31 is conduit 33.
Conduit 33 passes part of the refrigerant exiting from the
refrigerant expansion device 15 to chamber 31, thus substantially
filling the chamber 31 with refrigerant. The pressure of the
refrigerant in chamber 31 exerts a compressive force on the
bellows, thereby acting to withdraw movable means 24 from chamber
20. Acting in conjunction with the force developed by the
refrigerant in chamber 31 is the inherent compressive force of the
bellows 25. Acting in opposition to these two forces is the force
developed by the refrigerant in chamber 28, acting to expand the
bellows and thus to project movable means 24 further into chamber
20.
Connected to bellows 25 via capillary tube 32 is feeler bulb 27,
arranged to respond to the temperature of the refrigerant exiting
from the evaporator 17. Preferably, bulb 27 is attached to the
system suction line 18. A charge of refrigerant is contained in the
bulb 27.
As the temperature of the refrigerant exiting from the evaporator
17 increases, the temperature and pressure of the refrigerant
charge contained in bulb 27 correspondingly increases. The increase
in pressure is transmitted via capillary tube 32 to the refrigerant
charge contained in bellows 25, thereby affording a corresponding
increase in the pressure of the refrigerant contained in chamber
28. The pressurized refrigerant vapor thence exerts a force greater
than the compressive force of the bellows and the force developed
by the refrigerant contained in chamber 31, thereby acting to
expand the bellows 25. The expanding bellows 25 projects movable
member 24 further into chamber 20, thereby increasing the flow of
refrigerant to evaporator 17 as desired.
Conversely, if the temperature of the refrigerant exiting from the
evaporator 17 decreases, the resulting force acting on bellows 25
will compress the bellows, and thus will reduce the amount movable
member 24 projects into chamber 20. The flow of refrigerant to
evaporator 17 will thereby be decreased as desired.
It should be understood, other methods of controlling the movement
of means 24 may be utilized. In addition, the compressive force of
the bellows may be made adjustable, to vary the superheat control
in a manner well known to those skilled in the art.
The novel expansion device is relatively inexpensive to manufacture
and is relatively maintenance free. In addition, the device will be
adaptable to changes in refrigerant temperature exiting from the
evaporator to obtain optimum heat transfer performance from the
evaporator, and in addition, will prevent possible damage to the
compressor by liquid refrigerant entering the suction side of the
compressor.
While I have described and illustrated a preferred embodiment of my
invention, it will be understood that my invention is not limited
thereto, but may be otherwise embodied within the scope of the
following claims.
* * * * *