U.S. patent application number 15/914646 was filed with the patent office on 2018-09-13 for reverse cycle defrost refrigeration system.
The applicant listed for this patent is KEEPRITE REFRIGERATION, INC.. Invention is credited to Jacob Aaron CRANE, Yonghui XU.
Application Number | 20180259234 15/914646 |
Document ID | / |
Family ID | 63444544 |
Filed Date | 2018-09-13 |
United States Patent
Application |
20180259234 |
Kind Code |
A1 |
XU; Yonghui ; et
al. |
September 13, 2018 |
REVERSE CYCLE DEFROST REFRIGERATION SYSTEM
Abstract
A refrigeration system in which a refrigerant is circulatable,
the refrigeration system including an indoor coil assembly with an
indoor coil and a suction header subassembly connected with indoor
coil circuits of the indoor coil. The suction header subassembly
includes a hollow suction header body defining a suction header
bore therein and one or more extended spigots defining an extended
spigot bore therein for directing the refrigerant into a selected
one of the indoor coil circuits when operating in a defrost mode.
The extended spigot includes an open inner end that is located in
the suction header bore to receive a portion of the refrigerant
flowing therethrough when the refrigeration system is operating in
the defrost mode.
Inventors: |
XU; Yonghui; (Flower Mound,
TX) ; CRANE; Jacob Aaron; (Longview, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KEEPRITE REFRIGERATION, INC. |
Longview |
TX |
US |
|
|
Family ID: |
63444544 |
Appl. No.: |
15/914646 |
Filed: |
March 7, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62467916 |
Mar 7, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25B 13/00 20130101;
F25B 2339/0444 20130101; F28F 9/0282 20130101; F25B 39/028
20130101; F25B 41/003 20130101; F25B 47/025 20130101; F25B 2500/01
20130101; F28D 1/0477 20130101; F25B 2339/0446 20130101; F28F 9/026
20130101 |
International
Class: |
F25B 47/02 20060101
F25B047/02; F25B 39/02 20060101 F25B039/02; F25B 41/00 20060101
F25B041/00 |
Claims
1. A refrigeration system in which a refrigerant is circulatable,
the refrigeration system comprising: an indoor coil assembly
comprising: an indoor coil comprising a plurality of tubes defining
respective tube bores therein through which the refrigerant is
flowable, the tubes being arranged in a plurality of indoor coil
circuits respectively, each said indoor coil circuit extending
between an inlet end thereof, at which the refrigerant flows into
each said indoor coil circuit respectively when the refrigeration
system is operating in a refrigeration mode, and an outlet end
thereof, via which the refrigerant exits each said indoor coil
circuit respectively when the refrigeration system is operating in
the refrigeration mode, the refrigerant flowing through each said
indoor coil circuit from the outlet end to the inlet end thereof
when the refrigeration system is operating in a defrost mode; a
suction header subassembly connected with the indoor coil circuits
at the outlet ends thereof, the suction header subassembly
comprising: a hollow suction header body defining a suction header
bore therein through which the refrigerant is flowable in a first
direction when the refrigeration system operates in the
refrigeration mode, and through which the refrigerant flows in a
second direction, opposed to the first direction, when the
refrigeration system operates in the defrost mode; a plurality of
elongate spigots, each said spigot defining a spigot bore therein
through which the refrigerant is flowable, the spigots being formed
for connecting the tube bores of the respective indoor coil
circuits in fluid communication with the suction header bore via
the respective spigot bores; and the spigots comprising at least
one extended spigot comprising a main body portion and an inner end
portion thereof located in the suction header bore, the main body
portion being connected to a selected one of the indoor coil
circuits and the inner end portion comprising an open inner end in
fluid communication with an extended spigot bore of said at least
one extended spigot, the inner end portion being positioned to
locate the open inner end facing opposite to the second direction,
for receiving therein a portion of the refrigerant flowing in the
second direction through the suction header bore, said portion of
the refrigerant being directed via the open inner end through the
extended spigot bore into the selected one of the indoor coil
circuits for defrosting the selected one of the indoor coil
circuits, when the refrigeration system is operating in the defrost
mode.
2. The refrigeration system according to claim 1 in which: the open
inner end of said at least one extended spigot is defined by an end
portion axis; and the inner end portion is positioned in the
suction header bore to locate the end portion axis substantially
parallel with the second direction, for receiving the portion of
the refrigerant in the open inner end of said at least one extended
spigot when the refrigerant is flowing in the second direction.
3. The refrigeration system according to claim 1 in which: the
inner end portion extends between the open inner end thereof and an
outer end thereof; the inner end portion comprises an inner end
portion bore extending between the open inner end and the outer
end; and the main body portion extends between an outer part, at
which a main body portion bore of the main body portion is in fluid
communication with the tube bore of the tube of said selected one
of the indoor coil circuits, and an inner part, at which the main
body portion is connected with the outer end of the inner end
portion and the main portion bore is in fluid communication with
the inner end portion bore of the inner end portion.
4. The refrigeration system according to claim 1 in which the open
inner end is substantially centered in the suction header bore.
5. The refrigeration system according to claim 2 in which the open
inner end is substantially centered in the suction header bore.
6. A suction header subassembly connected with a plurality of
indoor coil circuits of an indoor coil in a refrigeration system at
respective outlet ends of the indoor coil circuits, each said
indoor coil circuit comprising a tube defining a tube bore therein
through which a refrigerant is flowable, each said indoor coil
circuit extending between an inlet end thereof, at which the
refrigerant flows into each said indoor coil circuit respectively
when the refrigeration system is operating in a refrigeration mode,
and the outlet end thereof, via which the refrigerant exits each
said indoor coil circuit respectively when the refrigeration system
is operating in the refrigeration mode, the refrigerant flowing
through each said indoor coil circuit from the outlet end to the
inlet end thereof when the refrigeration system is operating in a
defrost mode, the suction header subassembly comprising: a hollow
suction header body defining a suction header bore therein through
which the refrigerant is flowable in a first direction when the
refrigeration system operates in the refrigeration mode, and
through which the refrigerant flows in a second direction, opposed
to the first direction, when the refrigeration system operates in
the defrost mode; a plurality of elongate spigots, each said spigot
defining a spigot bore therein through which the refrigerant is
flowable, the spigots being formed for connecting the tube bores of
the respective indoor coil circuits in fluid communication with the
suction header bore via the respective spigot bores; and the
spigots comprising at least one extended spigot comprising a main
body portion and an inner end portion thereof located in the
suction header bore, the main body portion being connected to a
selected one of the indoor coil circuits and the inner end portion
comprising an open inner end in fluid communication with an
extended spigot bore of said at least one extended spigot, the
inner end portion being positioned to locate the open inner end
facing opposite to the second direction, for receiving a portion of
the refrigerant flowing in the second direction through the suction
header bore in the open inner end, said portion of the refrigerant
being directed via the open inner end through the extended spigot
bore into the selected one of the indoor coil circuits for
defrosting the selected one of the indoor coil circuits, when the
refrigeration system is operating in the defrost mode.
7. The suction header subassembly according to claim 6 in which:
the open inner end of said at least one extended spigot is defined
by an end portion axis; and the inner end portion is positioned in
the suction header bore to locate the end portion axis
substantially parallel with the second direction, for receiving the
portion of the refrigerant in the open end of said at least one
extended spigot when the refrigerant is flowing in the second
direction.
8. The suction header subassembly according to claim 6 in which:
the inner end portion extends between the open inner end thereof
and an outer end thereof, the inner end portion comprising an inner
end portion bore extending between the open inner end and the outer
end; and the main body portion extends between an outer part, at
which a main body portion bore of the main body portion is in fluid
communication with the tube bore of the tube of said selected one
of the indoor coil circuits, and an inner part, at which the main
body portion is connected with the outer end of the inner end
portion and the main portion bore is in fluid communication with
the inner end portion bore of the inner end portion.
9. The suction header subassembly according to claim 6 in which the
open inner end is substantially centered in the suction header
bore.
10. The suction header subassembly according to claim 7 in which
the open inner end is substantially centered in the suction header
bore.
11. An extended spigot for directing a portion of refrigerant
flowing in a preselected direction of flow through a suction header
bore of a suction header body to a selected one of a plurality of
hollow indoor coil circuits to defrost said selected one of the
indoor circuits, said selected one of the indoor coil circuits
comprising a tube defining a tube bore therein through which the
refrigerant is flowable, the extended spigot comprising: a main
body portion extending between inner and outer parts thereof; an
inner end portion extending between an outer end and an open inner
end thereof, the outer end being connected with the main body
portion at the inner part thereof; the outer part of the main body
portion being connected with the selected one of the plurality of
the indoor coil circuits; and the inner end portion being
positioned to locate the open inner end facing opposite to the
preselected direction of flow of the refrigerant through the
suction header bore, for receiving therein the portion of the
refrigerant.
12. The extended spigot according to claim 11 comprising an
extended spigot bore extending between the open inner end of the
inner end portion and the outer part of the main body portion,
through which the portion of the refrigerant is flowable to the
tube bore of the tube of the selected one of the indoor coil
circuits.
13. A method of defrosting an indoor coil in a refrigeration system
in which a refrigerant is circulatable, the indoor coil comprising
a plurality of indoor coil circuits, each said indoor coil circuit
comprising a tube defining a tube bore therein through which a
refrigerant is flowable, each said indoor coil circuit extending
between an inlet end thereof, at which the refrigerant flows into
each said indoor coil respectively when the refrigeration system is
operating in a refrigeration mode, and an outlet end thereof, via
which the refrigerant exits each said indoor coil circuit
respectively when the refrigeration system is operating in the
refrigeration mode, the refrigerant flowing through each said
indoor coil circuit from the outlet end to the inlet end thereof
when the refrigeration system is operating in a defrost mode, the
method comprising: (a) providing a hollow suction header body
defining a suction header bore therein through which the
refrigerant is flowable in a first direction when the refrigeration
system operates in the refrigeration mode, and through which the
refrigerant flows in a second direction, opposed to the first
direction, when the refrigeration system operates in the defrost
mode; (b) providing a plurality of elongate spigots, each said
spigot defining a spigot bore therein through which the refrigerant
is flowable, the spigots being formed for connecting the tube bores
of the respective indoor coil circuits in fluid communication with
the suction header bore via the respective spigot bores; (c)
providing at least one extended spigot comprising a main body
portion and an inner end portion thereof located in the suction
header bore, the main body portion being connected to a selected
one of the indoor coil circuits and the inner end portion
comprising an open inner end in fluid communication with an
extended spigot bore of said at least one extended spigot, the
inner end portion being positioned to locate the open inner end
facing opposite to the second direction; (d) permitting a portion
of the refrigerant flowing in the second direction through the
suction header bore to be received in the open inner end; and (e)
via the extended spigot bore, directing said portion of the
refrigerant from the open inner end into the selected one of the
indoor coil circuits for defrosting the selected one of the indoor
coil circuits, when the refrigeration system is operating in the
defrost mode.
14. The method according to claim 13 in which: the open inner end
of said at least one extended spigot is defined by an end portion
axis; and the inner end portion is positioned in the suction header
bore to locate the end portion axis substantially parallel with the
second direction, for receiving the portion of the refrigerant in
the open end of said at least one extended spigot when the
refrigerant is flowing in the second direction.
15. The method according to claim 13 in which: the inner end
portion extends between the open inner end thereof and an outer end
thereof, the inner end portion comprising an inner end portion bore
extending between the open inner end and the outer end; and the
main body portion extends between an outer part, at which a main
body portion bore of the main body portion is in fluid
communication with the tube bore of the tube of the selected one of
the indoor coil circuits, and an inner part, at which the main body
portion is connected with the outer end of the inner end portion
and the main portion bore is in fluid communication with the inner
end portion bore of the inner end portion.
16. The method according to claim 13 in which the open inner end is
substantially centered in the suction header bore.
17. The method according to claim 14 in which the open inner end is
substantially centered in the suction header bore.
18. A header subassembly connected with a plurality of coil
circuits of a tube fin coil in a refrigeration system at respective
second ends of respective coil circuits of the tube fin coil, each
said coil circuit comprising a tube defining a tube bore therein
through which a refrigerant is flowable, each said coil circuit
extending between a first end thereof, at which the refrigerant
flows into each said coil circuit respectively when the
refrigeration system is operating in a refrigeration mode, and the
second end thereof, via which the refrigerant exits each said coil
circuit respectively when the refrigeration system is operating in
the refrigeration mode, the refrigerant flowing through each said
coil circuit from the second end to the first end thereof when the
refrigeration system is operating in a defrost mode, the header
subassembly comprising: a hollow header body defining a header bore
therein through which the refrigerant is flowable in a first
direction when the refrigeration system operates in the
refrigeration mode, and through which the refrigerant flows in a
second direction, opposed to the first direction, when the
refrigeration system operates in the defrost mode; a plurality of
elongate spigots, each said spigot defining a spigot bore therein
through which the refrigerant is flowable, the spigots being formed
for connecting the tube bores of the respective indoor coil
circuits in fluid communication with the header bore via the
respective spigot bores; and the spigots comprising at least one
extended spigot comprising a main body portion and an inner end
portion thereof located in the header bore, the main body portion
being connected to a selected one of the indoor coil circuits and
the inner end portion comprising an open inner end in fluid
communication with an extended spigot bore of said at least one
extended spigot, the inner end portion being positioned to locate
the open inner end facing opposite to the second direction, for
receiving a portion of the refrigerant flowing in the second
direction through the header bore in the open inner end, said
portion of the refrigerant being directed via the open inner end
through the extended spigot bore into the selected one of the
indoor coil circuits for defrosting the selected one of the indoor
coil circuits, when the refrigeration system is operating in the
defrost mode.
Description
[0001] This application claims priority to U.S. Provisional Patent
Application No. 62/467,916, filed on Mar. 7, 2017, which is hereby
incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention is a reverse cycle defrost
refrigeration system with a coil assembly including a header
subassembly with one or more extended spigots for increasing flow
of the refrigerant in one or more selected coil circuits.
BACKGROUND OF THE INVENTION
[0003] As is well known in the art, an indoor coil in a vapor
compression refrigeration system typically is required to be
defrosted from time to time. Various devices and methods in this
regard are known. Many of the known defrosting methods, e.g.,
electric defrost and off-cycle defrost, have certain
disadvantages.
[0004] Reverse cycle defrost methods, in which the flow of the
refrigerant through the system is at least partially reversed,
provides certain advantages. However, in the prior art, certain
elements fundamental to the refrigeration system involve certain
disadvantages.
[0005] As is well known in the art, a suction header subassembly 20
is formed for use with an indoor coil that includes a number of
indoor coil circuits including tubes through which the refrigerant
flows (not shown in FIGS. 1A and 1B). A typical suction header
subassembly 20 of the prior art is illustrated in FIGS. 1A and 1B.
(As will be described, the balance of the drawings illustrates the
present invention.) Those skilled in the art would appreciate that
the suction header subassembly 20 as illustrated in FIGS. 1A and 1B
is exemplary only, as the prior art suction header subassemblies
are provided in a wide variety of configurations.
[0006] As can be seen in FIGS. 1A and 1B, the suction header
assembly 20 typically includes a suction header body 22 defining a
suction header bore 24 therein.
[0007] In the typical indoor coil assembly, the indoor coil
circuits are in fluid communication respectively with the suction
header bore 24 via hollow spigots 28. When the refrigeration system
in which the indoor coil is included is operating in a
refrigeration mode, the refrigerant flows through the indoor coil
circuits and exits therefrom, via the spigots 28, into the suction
header bore 24, and subsequently further exits therefrom, as
schematically represented by arrow "A" in FIGS. 1A and 1B.
[0008] In the refrigeration mode, the refrigerant flows into the
indoor coil circuits of the indoor coil at respective inlet ends of
the indoor coil circuits, and then flows from the indoor coil
circuits at respective outlet ends thereof into the bore 24 of the
suction header body 22 via respective spigot bores 29 of the
spigots 28 (FIG. 1B). In the refrigeration mode, the refrigerant
ultimately exits the suction header body 22 at an end 23 thereof
(FIG. 1A).
[0009] When the refrigeration system operates in a defrost mode,
the refrigerant is directed through the suction header bore 24 in
the direction indicated by arrow "B" in FIGS. 1A and 1B. In the
defrost mode, the refrigerant that flows into the suction header
bore 24 flows therefrom into the indoor coil circuits via the
spigots respectively. As can be seen in FIG. 1B, in the defrost
mode, the refrigerant flows in the indoor coil circuits in a
direction generally opposite to the direction in which it flows
when the refrigeration system is in the refrigeration mode.
[0010] Each spigot 28 has a connection portion engaged with the
body 22, via which the refrigerant may flow from the tube to the
suction header bore 24, and vice versa. For clarity of
illustration, the connection portions of the spigots 28, at which
the respective bores 29 of the spigots 28 are in fluid
communication with the suction header bore 24, are respectively
identified in FIG. 1B by reference characters 26A-26E.
[0011] In the prior art, when operating the refrigeration system
during the defrost mode, it may be found that one or more of the
indoor coil circuits defrosts at a slower rate than others. Because
of this, the refrigeration system may remain in the defrost mode
for a relatively long time, in order to defrost the entire indoor
coil. However, prolonged operation in the defrost mode may have
various undesirable consequences.
[0012] As is well known in the art, there may be various reasons
for an indoor coil circuit being relatively slow to defrost. One
possible reason appears to be that the flow of the warm refrigerant
into the indoor coil circuit is less than the flow thereof through
the other indoor coil circuits.
[0013] The one or more indoor coil circuits that are relatively
slow to defrost may be physically located below the other indoor
coil circuits.
[0014] For example, where the lowermost indoor coil circuit is
relatively slow to defrost, it may be that this is ultimately due
to a relatively lower static pressure at the lowermost connection
portion 26E. Those skilled in the art would appreciate that, when
in the defrost mode, the refrigerant in the respective spigots 28
at the connection portions 26A-26E thereof is subjected to
predominantly static pressure, because the spigots 28 do not extend
into the bore 24 at the connection portions 26A-26E. It is also
believed that such static pressure is greatest at the connection
portion 26A, and is lowest at the connection portion 26E, based on
differences in rates of flow of the refrigerant into the respective
tubes, when the refrigeration system is operating in the defrost
mode.
[0015] Accordingly, in these circumstances, relatively more of the
refrigerant flows through the connection portions 26A-26D into the
tubes connected therewith via the respective spigots than through
the connection portion 26E.
[0016] From the foregoing, it can be seen that, where the lowermost
indoor coil circuit is the slowest to defrost, this may be due to a
relatively slower rate of flow of the warm refrigerant into the
lowermost indoor coil circuit. It is believed that the relatively
slower flow rate of the refrigerant into the lowermost connection
portion 26E, when operating in defrost mode, may be at least
partially due to the relatively lower static pressure of the
refrigerant at the connection portion 26E.
[0017] The indoor coil circuit that is relatively slower to defrost
is not necessarily the lowermost circuit, and there may be
different reasons for such slow rate of defrost.
SUMMARY OF THE INVENTION
[0018] For the foregoing reasons, there is a need for a
refrigeration system that overcomes or mitigates one or more of the
disadvantages or defects of the prior art. Such disadvantages or
defects are not necessarily included in those described above.
[0019] In its broad aspect, the invention provides a refrigeration
system in which a refrigerant is circulatable, the refrigeration
system including an indoor coil assembly. The indoor coil assembly
includes an indoor coil and a suction header subassembly connected
with indoor coil circuits of the indoor coil at outlet ends of the
indoor coil circuits. The suction header subassembly includes a
hollow suction header body defining a suction header bore therein
through which the refrigerant is flowable in a first direction when
the refrigeration system operates in the refrigeration mode, and
through which the refrigerant flows in a second direction, opposed
to the first direction, when the refrigeration system operates in
the defrost mode. The suction header subassembly also includes a
number of elongate spigots, each spigot defining a spigot bore
therein through which the refrigerant is flowable, the spigots
being formed for connecting the tube bores of the respective indoor
coil circuits in fluid communication with the suction header bore
via the respective spigot bores. The spigots include one or more
extended spigots that each include a main body portion and an inner
end portion thereof located in the suction header bore. The main
body portion is connected to a selected one of the indoor coil
circuits and the inner end portion includes an open inner end in
fluid communication with an extended spigot bore of the extended
spigot. The inner end portion is positioned to locate the open
inner end facing opposite to the second direction, for receiving
therein a portion of the refrigerant flowing in the second
direction through the suction header bore. The portion of the
refrigerant is directed via the open inner end through the extended
spigot bore into the selected one of the indoor coil circuits for
defrosting the selected one of the indoor coil circuits, when the
refrigeration system is operating in the defrost mode.
[0020] In another of its aspects the invention provides a header
subassembly connected with a number of coil circuits of a tube fin
coil in a refrigeration system at respective second ends of the
respective coil circuits of the tube fin coil. Each coil circuit
includes a tube defining a tube bore therein through which a
refrigerant is flowable. Each coil circuit extends between a first
end thereof, at which the refrigerant flows into each coil circuit
respectively when the refrigeration system is operating in a
refrigeration mode, and the second end thereof, via which the
refrigerant exits each coil circuit respectively when the
refrigeration system is operating in the refrigeration mode. The
refrigerant flows through each coil circuit from the second end to
the first end thereof when the refrigeration system is operating in
a defrost mode. The header subassembly includes a hollow header
body defining a header bore therein through which the refrigerant
is flowable in a first direction when the refrigeration system
operates in the refrigeration mode, and through which the
refrigerant flows in a second direction, opposed to the first
direction, when the refrigeration system operates in the defrost
mode. The header subassembly also includes a number of elongate
spigots. Each spigot defines a spigot bore therein through which
the refrigerant is flowable. The spigots are formed for connecting
the tube bores of the respective indoor coil circuits in fluid
communication with the header bore via the respective spigot bores.
The spigots include one or more extended spigots, each including a
main body portion and an inner end portion thereof located in the
header bores. The main body portion is connected to a selected one
of the indoor coil circuits and the inner end portion includes an
open inner end in fluid communication with an extended spigot bore
of the extended spigot. The inner end portion is positioned to
locate the open inner end facing opposite to the second direction,
for receiving a portion of the refrigerant flowing in the second
direction through the header bore in the open inner end. The
portion of the refrigerant is directed via the open inner end
through the extended spigot bore into the selected one of the
indoor coil circuits for defrosting the selected one of the indoor
coil circuits, when the refrigeration system is operating in the
defrost mode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The invention will be better understood with reference to
the attached drawings, in which:
[0022] FIG. 1A (also described previously) is a side view of a
suction header assembly of the prior art;
[0023] FIG. 1B (also described previously) is a cross-section of
the prior art suction header assembly of FIG. 1A, taken along line
1-1 in FIG. 1A;
[0024] FIG. 2A is an isometric view of an embodiment of a suction
header subassembly of the invention attached to an indoor coil,
drawn at a smaller scale;
[0025] FIG. 2B is another isometric view of the suction header
subassembly and the indoor coil of FIG. 2A, drawn at a smaller
scale;
[0026] FIG. 2C is another isometric view of the suction header
subassembly and the indoor coil of FIGS. 2A and 2B;
[0027] FIG. 3A is an isometric view of the suction header
subassembly of FIG. 2A and a number of spigots, drawn at a larger
scale;
[0028] FIG. 3B is an isometric view of the suction header
subassembly of FIG. 2A, showing interior portions of a suction
header body of the suction header subassembly and an embodiment of
an extended spigot of the invention;
[0029] FIG. 4A is a side view of an embodiment of the suction
header subassembly and the spigots and the extended spigot of FIGS.
3A and 3B, drawn at a smaller scale;
[0030] FIG. 4B is a cross-section of the suction header subassembly
and the spigots and the extended spigot of FIG. 4A, taken along
line 2-2 in FIG. 4A;
[0031] FIG. 4C is a view of a portion of FIG. 4B identified as 3
therein, drawn at a larger scale;
[0032] FIG. 5A is a side view of the extended spigot of FIG. 3B,
drawn at a larger scale;
[0033] FIG. 5B is an isometric view of the extended spigot of FIG.
5A;
[0034] FIG. 6 is an isometric view of an alternative embodiment of
the extended spigot of the invention;
[0035] FIG. 7 is a schematic diagram of an embodiment of a reverse
cycle defrost refrigeration system of the invention;
[0036] FIG. 8 is an isometric view of an embodiment of an outlet
end distributor subassembly of the invention, drawn at a larger
scale;
[0037] FIG. 9 is a side view of an alternative embodiment of the
outlet end distributor subassembly of the invention;
[0038] FIG. 10A is a side view of an alternative embodiment of an
open inner end of the extended spigot of the invention, drawn at a
larger scale;
[0039] FIG. 10B is a side view of another alternative embodiment of
the open inner end of the extended spigot of the invention; and
[0040] FIG. 10C is a side view of another alternative embodiment of
the open inner end of the extended spigot of the invention.
DETAILED DESCRIPTION
[0041] In the attached drawings, like reference numerals designate
corresponding elements throughout. To simplify the description, the
reference numerals used in FIGS. 1A and 1B will generally be used
in the description, except that each such reference numeral is
raised by 100 (or multiples thereof, as the case may be), where the
elements described correspond generally to prior art elements
already described. Reference is made to FIGS. 2A-7 to describe an
embodiment of a refrigeration system of the invention indicated
generally by the numeral 130. An embodiment of the refrigeration
system 130 of the invention is schematically illustrated in FIG.
7.
[0042] In the refrigeration system 130, a refrigerant (not shown)
is circulatable in a first direction (indicated by arrows "F1"-"F4"
in FIG. 7) to transfer heat out of a volume of air in a controlled
space (not shown) adjacent to an indoor coil assembly 132 of the
system when the system is operating in a refrigeration mode, and
the refrigerant is circulatable in a second direction (indicated by
arrows "S1"-"S4" in FIG. 7) at least partially opposite to the
first direction when the system is operating in a defrost mode. The
indoor coil assembly 132 (also identified by reference numeral E-4
in FIG. 7) includes an indoor coil 134 (FIGS. 2A-2C). The indoor
coil 134 includes a number of indoor coil circuits "C" that include
a number of tubes 136 respectively extending between first and
second sides 138, 140 of the indoor coil assembly 132 (FIG. 2A). It
will be understood that the tubes 136 define respective tube bores
or cavities 137 therein, through which the refrigerant may flow
(FIG. 4C). Each of the indoor coil circuits extends between an
inlet end 145 and an outlet end 147 thereof (FIG. 2B). It will be
understood that, although a number of the indoor coil circuits are
illustrated in FIG. 2B, only one circuit "C" is identified in FIG.
2B, for clarity of illustration.
[0043] Those skilled in the art would appreciate that the
refrigeration system 130 includes a number of additional elements.
For example, as can be seen in FIG. 7, the refrigeration system 130
preferably also includes: [0044] a compressor E-1; [0045] an
outdoor coil assembly E-2; [0046] a receiver E-3; [0047] a
reversing valve V-1; and [0048] an expansion valve V-4. Those
skilled in the art would be aware of the manner in which these
elements cooperate when the refrigeration system is operating in
the refrigeration mode and in the defrost mode. Accordingly,
further discussion of these elements is unnecessary.
[0049] When the refrigeration system is operating in the
refrigeration mode, the refrigerant flows into the respective
indoor coil circuits at the inlet ends 145 thereof, and exits the
respective indoor coil circuits at the outlet ends 147 thereof. The
refrigerant flows through each of the indoor coil circuits "C" from
the outlet end 147 thereof to the inlet end 145 thereof of the
indoor coil circuit when the refrigeration system is operating in
the defrost mode. (It will be understood that an inlet side
distributor assembly that is connected to the inlet ends 145 is
omitted from FIGS. 2A-2C for clarity of illustration.)
[0050] Each of the tubes 136 preferably includes at least first and
second parts 142, 144 extending between the first and second sides
138, 140 of the indoor coil 134 and at least a connecting loop 146
at the second side 140 that connects the first and second parts
142, 144 so that they are in fluid communication with each
other.
[0051] Preferably, the indoor coil assembly 134 also includes a
suction header subassembly 148 that is connected with the indoor
coil circuits "C" at the outlet ends 147 thereof. In one
embodiment, the suction header subassembly 148 preferably includes
a hollow suction header body 150 defining a suction header bore 152
therein through which the refrigerant is flowable in a first
direction when the refrigeration system 130 operates in the
refrigeration mode, and through which the refrigerant flows in a
second direction, opposed to the first direction, when the
refrigeration system 130 operates in the defrost mode. The
direction of flow of the refrigerant in the first and second
directions is schematically indicated by arrows "F" and "S"
respectively in FIGS. 4A and 4B. Preferably, the suction header
subassembly 148 also includes a number of elongate spigots 154.
Each spigot 154 defines a spigot bore 156 therein through which the
refrigerant is flowable (FIG. 4B). The spigots 154 are formed for
connecting the tube bores 137 of the respective indoor coil
circuits "C" in fluid communication with the suction header bore
152 via the respective spigot bores 156.
[0052] Those skilled in the art would appreciate that the suction
header body 150 may have any suitable configuration. For instance,
as can be seen in FIGS. 2A-2C, in one embodiment, the suction
header body preferably includes first and second straight portions
160, 162 that are joined by an elbow portion 163.
[0053] As will be described, it is preferred that the spigots 154
include one or more extended spigots 154.sub.L. Preferably, the
extended spigot 154.sub.L includes a main body portion 180 and an
inner end portion 182 thereof located in the suction header bore
152 (FIGS. 3A, 3B, 4B, 4C, 5A, 5B). It is also preferred that the
main body portion 180 is connected to a selected one of the indoor
coil circuits "C", as will be described. The inner end portion 182
preferably includes an open inner end 184 that is in fluid
communication with an extended spigot bore 101 of the extended
spigot 154.sub.L, as will also be described. Preferably, the inner
end portion 182 is positioned to locate the open inner end 184
facing opposite to the second direction, for receiving therein a
portion of the refrigerant flowing in the second direction through
the suction header bore 152. The portion of the refrigerant that is
directed via the open inner end 184 through the extended spigot
bore 101 flows into the selected one of the indoor coil circuits
"C" for defrosting the selected one of the indoor coil circuits
"C", when the refrigeration system 130 is operating in the defrost
mode. The portion of the refrigerant that is captured at the open
inner end 184 is schematically represented by arrow "D" in FIGS.
3B, 4B, and 4C.
[0054] An embodiment of the extended spigot 154.sub.L of the
invention is illustrated in FIGS. 3A, 3B, 4A, 4B, and 4C. The
indoor coil circuit to which the extended spigot 154.sub.L is
attached is identified in FIG. 4B, for clarity of illustration, by
reference character "C.sub.1". The extended spigot 154.sub.L is
connected to the outlet end of the selected indoor coil circuit
"C.sub.1". As noted above, there may be one or more indoor coil
circuits that are relatively slow to defrost. The selected indoor
coil circuits, to which the extended spigots are attached, are
selected because they are relatively slow to defrost. Although the
indoor coil circuit "C.sub.1" as illustrated in FIG. 4B is the
lowermost indoor coil circuit, it will be understood that the
selected indoor coil circuits do not necessarily include the
lowermost indoor coil circuit.
[0055] As can be seen in FIG. 4C, the open inner end 184 preferably
is formed and positioned in the suction header bore 152 to receive
the portion of the refrigerant flowing through the suction header
bore 152 in the direction indicated by the arrow "S" (i.e., in the
second direction), i.e., while the refrigeration system 130 is
operating in the defrost mode. The open inner end 184 is positioned
to accept the portion of the refrigerant flowing therethrough.
[0056] Those skilled in the art would appreciate that the extended
spigot 154.sub.L, and in particular the inner end portion 182, may
have any suitable configuration. In one embodiment, the open inner
end 184 of the extended spigot 154.sub.L preferably is defined by
an end portion axis "X" (FIG. 4C). It is also preferred that the
inner end portion 182 is positioned in the suction header bore 152
to locate the end portion axis "X" substantially parallel with the
second direction, for receiving the portion of the refrigerant in
the open inner end 184 of the extended spigot 154.sub.L when the
refrigerant is flowing in the second direction. In one embodiment,
and as can be seen in FIG. 4C, the open inner end 184 preferably is
defined by ends 102, 103 of the extended spigot 154.sub.L that are
positioned parallel to each other, to define a plane "P.sub.1" that
is substantially orthogonal to the end portion axis "X". In one
embodiment, the open inner end 184 preferably is located so that
the plane "P.sub.1" defined by the ends 102, 103 is substantially
orthogonal to the second direction, in which the refrigerant flows
during defrost mode.
[0057] The portion of the refrigerant that is captured in the open
inner end 184 (represented by arrow "D" in FIGS. 4B and 4C) is
directed through the extended spigot bore 101 to the tube bore 137
of the tube that is included in the selected indoor coil circuit
"C.sub.1". The flow of the captured portion of the refrigerant
through the extended spigot bore 101 and into the tube bore 137 is
schematically represented by arrow "D.sub.1" in FIG. 4B for clarity
of illustration.
[0058] As can be seen, for example, in FIGS. 5A and 5B, in one
embodiment, the main body portion 180 of the extended spigot
154.sub.L preferably is substantially straight, and the inner end
portion 182 preferably has an elbow shape. Preferably, the inner
end portion 182 extends between the open inner end 184 thereof and
an outer end 104 thereof (FIGS. 5A, 5B). It is also preferred that
the inner end portion 182 includes an inner end portion bore 105
extending between the open inner end 184 and the outer end 104
thereof (FIG. 4C). Preferably, the main body portion 180 has an
outer part 106, at which the main body portion 180 is connected
with the tube 136 of the selected one of the indoor coil circuits
"C.sub.1". It is preferred that the main body portion 180 extends
between the outer part 106 and an inner part 108 thereof, at which
the main body portion 180 is connected with the outer end 104 of
the inner end portion 182 and a main body portion bore 107 is in
fluid communication with the inner end portion bore 105 of the
inner end portion 182 (FIG. 4C). The extended spigot bore 101
includes the inner end bore 105 and the main portion bore 107.
[0059] Preferably, the extended spigot 154.sub.L includes the
extended spigot bore 101 extending between the open inner end 184
of the inner end portion 182 and the outer part 106 of the main
body portion 180, through which the portion of the refrigerant is
flowable to the tube bore 137 of the tube of the selected indoor
coil circuit "C.sub.1" (FIG. 4C).
[0060] It will be understood that the spigots may include more than
one extended spigot. It will also be understood that the one or
more indoor coil circuits with insufficient refrigerant flow
therethrough when the refrigeration system is operating in the
defrost mode may be located at any position in the indoor coil.
[0061] It will be understood that the open inner end 184 may be
positioned in any suitable location inside the suction header bore
152. In one embodiment, the open inner end 184 preferably is
substantially centered in the suction header bore 152.
[0062] As noted above, the extended spigot 154.sub.L may be
provided in various forms. The embodiment of the extended spigot
154.sub.L illustrated in FIGS. 5A and 5B preferably includes the
main body portion 180 thereof, extending between its inner and
outer parts 108, 106 respectively. As can be seen, for instance, in
FIG. 5A, in one embodiment, the main body portion 180 preferably is
substantially straight. When the extended spigot 154.sub.L is
attached to the suction header body 150, the inner end portion 182
preferably is positioned to locate the open inner end 184 so that
the open inner end 184 is facing opposite to the preselected
direction of flow of the refrigerant through the suction header
bore, for receiving therein the portion of the refrigerant.
[0063] It has been found that the extended spigot 154.sub.L has
increased the flow rate of the refrigerant through the selected
indoor coil circuit "C.sub.1", when the refrigeration system is
operating in the defrost mode. Without wishing to be bound by any
theory, it is believed that the increased flow rate of the
refrigerant is due to the location of the open inner end 184, i.e.,
positioning the open inner end 184 in the suction header bore 152
facing opposite to the direction of flow of the refrigerant to
receive the portion of the refrigerant therein, when the
refrigeration system is operating in the defrost mode. Such
location and orientation of the open inner end results in the
refrigerant at the open inner end being subjected to an increased
dynamic pressure, which causes the flow of the refrigerant through
the extended spigot to be increased.
[0064] As can be seen in FIG. 5A, in one embodiment, the main body
portion 180 preferably is substantially defined by an axis "Q"
(FIG. 5A), and the axis "X" of the open inner end 184 preferably is
positioned substantially orthogonal to the axis "Q" of the main
body portion.
[0065] It will be understood that the extended spigot may be
provided in any suitable form. Due to variations in indoor coil
design, the extended spigot may be provided in a variety of
configurations. For instance, an alternative embodiment of the
extended spigot 254.sub.L is illustrated in FIG. 6. As can be seen
in FIG. 6, in one embodiment, the extended spigot 254.sub.L
preferably includes a main body portion 280, an inner end portion
282, and an intermediate portion 209 located between, and connected
with, the main body portion 280 and the inner end portion 282.
Preferably, the main body portion 280 extends between an outer part
206 and an inner part 207 thereof. The intermediate portion 209
preferably extends between a first end 210 and a second end 211
thereof. The inner part 207 of the main body portion 280 is
connected with the first end 210 of the intermediate portion 209.
Similarly, the second end 211 of the intermediate portion 209 is
connected with the outer end 204 of the inner end portion 282. As
can be seen in FIG. 6, the inner end portion 282 includes an open
inner end 284.
[0066] The alternative embodiment illustrated in FIG. 6 is
exemplary only. It will be understood that the extended spigot
254.sub.L is formed to connect a flow-deficient indoor circuit (not
shown in FIG. 6) and a suction header bore (not shown in FIG. 6) in
fluid communication with each other. The extended spigot 254.sub.L
is formed and positioned to locate the open inner end 284 in the
suction header bore so that the open inner end 284 is facing
opposite to the direction in which the refrigerant is flowing,
during operation in the defrost mode, to receive a portion of the
refrigerant in the open inner end 284.
[0067] It will be understood that the extended spigot 254.sub.L
preferably is hollow throughout, to define an extended spigot bore
therein. As can be seen in FIG. 6, each of the main body portion
280, the intermediate portion 209, and the inner end portion 282 is
substantially straight. Those skilled in the art would appreciate
that the extended spigot may have any suitable form required in
order to connect a flow-deficient indoor coil circuit and the
suction header bore in fluid communication with each other and to
locate the open inner end of the extended spigot in the suction
header bore facing opposite to the direction of flow of the
refrigerant, when the refrigeration system is operating in the
defrost mode. The extended spigot 254.sub.L is shown connecting the
suction header body with an indoor coil circuit in FIGS. 2B and
2C.
[0068] It will be understood that certain elements are omitted from
the drawings, for clarity. For example, in FIG. 2C, an end plate of
the indoor coil assembly is omitted for clarity of illustration. It
is also understood that the indoor coil may also be incorporated
into other types of refrigeration systems, including but not
limited to, e.g., a compressor rack, or any other multiple
compressor systems.
[0069] Those skilled in the art would appreciate that, as noted
above, there may be a number of reasons for an uneven defrost
pattern in the indoor coil resulting from different rates of
defrost in the respective indoor coil circuits. However, it is
believed that the main cause (or at least one of the main causes)
of the uneven defrost pattern in the prior art is the different
flow rates of the refrigerant through the spigots (and ultimately
through the respective indoor coil circuits) in the defrost mode. A
deficiency in the flow of the refrigerant may be due to various
causes.
[0070] In the foregoing description, the lowermost spigot was
flow-deficient. However, it will be understood by those skilled in
the art that, depending on the configuration of the suction header
and related elements, the lowermost spigot is not necessarily
flow-deficient. Accordingly, the foregoing description is
exemplary, and one or more similarly flow-deficient spigots may be
connected with the suction header body at any point in the suction
header body. The extended spigot may be installed to correct a
slower rate of refrigerant flow at any location on the suction
header body accordingly.
[0071] Alternative arrangements may be provided to address the
deficiency of refrigerant flow in the flow-deficient spigot. For
example, as illustrated in FIGS. 10A-10C, alternative embodiments
of the inner end portion of the extended spigot may be used to
provide the additional dynamic pressure required to increase the
flow of refrigerant into an otherwise flow-deficient spigot.
[0072] For instance, in FIG. 10A, an embodiment of the extended
spigot 354.sub.L of the invention is illustrated in which spigot
ends 302, 303 thereof define a plane "P.sub.2" positioned at a
predetermined acute angle .theta. relative to the direction of flow
of the refrigerant through the bore 152 of the suction header body
150. The spigot ends 302, 303 of the extended spigot 354.sub.L also
define an open inner end 384 therein in an inner end portion 382,
positioned to receive the portion of the refrigerant, as indicated
by arrow "D". The flow of the refrigerant through the suction
header bore 152 when the refrigeration system is operating in the
defrost mode is generally indicated by arrow "S". As can be seen in
FIG. 10A, the inner end portion 382 preferably is curved, to
position the open inner end 384 for receiving the portion of the
refrigerant flowing through the suction header bore 152. The open
inner end 384 is located in this way to cause the desired increase
in dynamic pressure in the spigot 354.sub.L, to provide an
increased flow of the refrigerant through the extended spigot
354.sub.L. The inner end portion 382 is slightly curved to locate
the plane "P.sub.2" at the predetermined angle .theta..
[0073] Another alternative embodiment of the extended spigot
454.sub.L of the invention is illustrated in FIG. 10B. The extended
spigot 454.sub.L preferably includes an open inner end 484
positioned to receive the portion of the refrigerant flowing
through the suction header bore 152. The open inner end 484
preferably is defined by parts 412, 413 of the extended spigot
454.sub.L that are positioned substantially orthogonal to the
direction of the flow of refrigerant through the suction header
bore 152. The extended spigot 454.sub.L additionally includes a
second aperture 414 at its inner end portion 482. In FIG. 10B, the
direction of flow of the refrigerant through the suction header
bore 152 is generally indicated by the arrow "S", i.e., the
refrigeration system is operating in the defrost mode. The portion
of the refrigerant flowing into the open inner end 484 is
schematically represented by arrow "D" in FIG. 10B. The open inner
end 484 is located to cause the desired increase in dynamic
pressure in the spigot 454.sub.L, to provide an increased flow of
the refrigerant through the extended spigot 454.sub.L.
[0074] Another alternative embodiment of the extended spigot
554.sub.L is illustrated in FIG. 100. The extended spigot 554.sub.L
preferably includes an inner end portion 582 that is located
substantially orthogonal to the direction of flow of the
refrigerant through the suction header bore 152. Preferably, the
inner end portion 582 includes a longer part 515 that is located
downstream relative to the flow of refrigerant when the
refrigeration system is in the defrost most, and a shorter part
that is located upstream.
[0075] As can be seen in FIG. 10C, in one embodiment, the longer
part 515 preferably extends into the suction header bore 152, and
the shorter part 516 does not extend into the suction header bore
152. The longer part 515 and the shorter part 516 terminate at ends
517, 518 respectively. The extended spigot 554.sub.L preferably
also includes an open inner end 584 located between the spigot ends
517, 518. The spigot ends 517, 518 preferably define a plane
"P.sub.3" that is positioned at a preselected angle .alpha.
relative to the direction of flow of the refrigerant in the defrost
mode, to receive the portion of the refrigerant in the open inner
end 584. In FIG. 10C, the direction of flow of the refrigerant in
the suction header bore 152 when the refrigeration system is
operating in the defrost mode is indicated by the arrow "S". The
flow of the portion of the refrigerant into the open inner end 584
is schematically represented by arrow "D" in FIG. 10C. The open
inner end 584 is located to cause the desired increase in dynamic
pressure in the spigot 554.sub.L, to provide an increased flow of
the refrigerant through the extended spigot 554.sub.L.
[0076] Embodiments of the extended spigot of the invention may be
used to increase the flow of the refrigerant in a coil circuit when
the refrigeration system is operating in either the refrigeration
mode or the defrost mode. Further alternative arrangements may be
used to address deficiencies of refrigerant flow in variously
positioned tubes in the indoor coil. For instance, as can be seen
in FIG. 8, an inlet end distributor subassembly 596 may be used to
distribute the refrigerant more evenly via inlet ends of the coil
circuits, when the refrigeration system is operating in the
refrigeration mode. As described above, the inlet end distributor
subassembly is connected with a number of spigots, and the spigots
are respectively connected with the inlet ends of the coil
circuits. The direction of flow of the refrigerant through the
distributor subassembly 596, when the refrigeration system is
operating in the refrigeration mode, is indicated by the arrows "F"
in FIG. 8.
[0077] An alternative embodiment of the outlet end distributor
subassembly 696 is illustrated in FIG. 9. The outlet end
distributor subassembly 696 is also connected with the outlet end
of the indoor coil circuits, via the spigots. The direction of flow
of the refrigerant through the distributor subassembly 696 when the
refrigeration system is operating in the defrost mode is indicated
by the arrow "S" in FIG. 9.
[0078] The invention also includes a method of defrosting the
indoor coil in the refrigeration system 130. In one embodiment, the
method preferably includes providing the hollow suction header body
150 defining the suction header bore 152 therein through which the
refrigerant is flowable in a first direction when the refrigeration
system operates in the refrigeration mode, and through which the
refrigerant flows in a second direction, opposed to the first
direction, when the refrigeration system operates in the defrost
mode. Also, a number of elongate spigots are provided, each spigot
defining a spigot bore therein through which the refrigerant is
flowable. The spigots are formed for connecting the tube bores of
the respective indoor coil circuits in fluid communication with the
suction header bore via the respective spigot bores. In addition,
one or more extended spigots are provided. The extended spigot
includes the main body portion and the inner end portion thereof,
the inner end portion being at least partially located in the
suction header bore. The main body portion is connected to the
selected one of the indoor coil circuits. The inner end portion
includes the open inner end in fluid communication with the
extended spigot bore of the extended spigot. The inner end portion
is positioned to locate the open inner end so that it is facing
opposite to the second direction (FIG. 4C). A portion of the
refrigerant flowing in the second direction through the suction
header bore is permitted to be received in the open inner end. Via
the extended spigot bore, the portion of the refrigerant is
directed from the open inner end into the selected one of the
indoor coil circuits for defrosting the selected one of the indoor
coil circuits, when the refrigeration system is operating in the
defrost mode.
[0079] It will be appreciated that the invention has many
applications other than in connection with hot gas defrost, as
described above. The extended spigot may be used in any tube fin
coil (e.g., whether the tube fin coil is utilized as an evaporator
or as a condenser when the refrigeration system is operating in the
refrigeration mode), to increase the flow of the refrigerant
through one or more selected coil circuits.
[0080] It will be appreciated by those skilled in the art that the
invention can take many forms, and that such forms are within the
scope of the invention as claimed. The scope of the claims should
not be limited by the preferred embodiments set forth in the
examples, but should be given the broadest interpretation
consistent with the description as a whole.
* * * * *