U.S. patent application number 15/825201 was filed with the patent office on 2019-05-30 for microchannel heat exchanger.
The applicant listed for this patent is Lennox Industries, Inc.. Invention is credited to Vijaykumar Sathyamurthi.
Application Number | 20190162455 15/825201 |
Document ID | / |
Family ID | 64500255 |
Filed Date | 2019-05-30 |
United States Patent
Application |
20190162455 |
Kind Code |
A1 |
Sathyamurthi; Vijaykumar |
May 30, 2019 |
MICROCHANNEL HEAT EXCHANGER
Abstract
A microchannel heat exchanger includes at least one manifold and
at least one a microchannel tube. The microchannel tube includes a
plurality of ports, and the microchannel tube extends from the at
least one manifold. The plurality of ports each have a width and a
height. The microchannel heat exchanger further includes at least
one fin extending from the at least one manifold. The fins are
arranged between the at least one microchannel tube and a second
microchannel tube. The microchannel heat exchanger further includes
a refrigerant arranged to flow through the microchannel tube. At
least one port of the plurality of ports has a cross-section area
less than 0.35 millimeters squared.
Inventors: |
Sathyamurthi; Vijaykumar;
(Carrollton, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lennox Industries, Inc. |
Richardson |
TX |
US |
|
|
Family ID: |
64500255 |
Appl. No.: |
15/825201 |
Filed: |
November 29, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F24F 1/18 20130101; F28F
9/0212 20130101; F28F 1/04 20130101; F28D 1/05391 20130101; F28D
1/0426 20130101; F28F 2260/02 20130101; F28F 2210/00 20130101; F28F
9/0243 20130101; F28F 13/00 20130101; F25B 39/04 20130101; F28F
9/0209 20130101; F28F 1/126 20130101; F28D 1/024 20130101; F28D
2021/0068 20130101; F25B 2339/04 20130101; F28F 1/022 20130101 |
International
Class: |
F25B 39/04 20060101
F25B039/04; F28F 1/12 20060101 F28F001/12; F28F 1/04 20060101
F28F001/04; F28F 13/00 20060101 F28F013/00 |
Claims
1. A microchannel heat exchanger, comprising: at least one
manifold; at least one a microchannel tube comprising a plurality
of ports, the at least one microchannel tube extending from the at
least one manifold, the plurality of ports each having a width, a
height, and a cross-section area; at least one fin extending from
the at least one manifold and arranged between the at least one
microchannel tube and a second microchannel tube; a refrigerant
arranged to flow through the microchannel tube; and wherein at
least one port of the plurality of ports has a cross-section area
less than 0.35 millimeters squared.
2. The microchannel heat exchanger of claim 1, wherein at least one
of the plurality of ports has an aspect ratio greater than 1.5.
3. The microchannel heat exchanger of claim 1, wherein at least one
of the plurality of ports has a height less than 0.6
millimeters.
4. The microchannel heat exchanger of claim 1, wherein at least one
of the plurality of ports has an aspect ratio of approximately 1.0,
a height less than 0.5 millimeters, and a width less than 0.5
millimeters.
5. The microchannel heat exchanger of claim 1, further comprising a
fan, the fan arranged to blow air across the at least one fin.
6. The microchannel heat exchanger of claim 1, wherein the at least
one manifold is in communication with a heating, ventilation, and
air conditioning system.
7. The microchannel heat exchanger of claim 1, comprising a low
global warming potential (low-GWP) refrigerant.
8. A condenser, comprising: an enclosure; and a microchannel heat
exchanger enclosed within the enclosure, the microchannel heat
exchanger comprising: at least one manifold; at least one a
microchannel tube comprising a plurality of ports, the at least one
microchannel tube extending from the at least one manifold, the
plurality of ports each having a width, a height, and a
cross-section area; at least one fin extending from the at least
one manifold and arranged between the at least one microchannel
tube and a second microchannel tube; a refrigerant arranged to flow
through the microchannel tube; and wherein at least one port of the
plurality of ports has a cross-section area less than 0.35
millimeters squared.
9. The condenser of claim 8, wherein at least one of the plurality
of ports has an aspect ratio greater than 1.5.
10. The condenser of claim 8, wherein at least one of the plurality
of ports has a height less than 0.6 millimeters.
11. The condenser of claim 8, wherein at least one of the plurality
of ports has an aspect ratio of approximately 1.0, a height less
than 0.5 millimeters, and a width less than 0.5 millimeters.
12. The condenser of claim 8, further comprising a fan, the fan
arranged to blow air across the at least one fin.
13. The condenser of claim 8, wherein the at least one manifold is
in communication with a heating, ventilation, and air conditioning
system.
14. The condenser of claim 8, comprising a low global warming
potential (low-GWP) refrigerant.
15. A heating, ventilation, and air conditioning (HVAC) system,
comprising: a condenser; and a microchannel heat exchanger, the
microchannel heat exchanger comprising: at least one manifold; at
least one a microchannel tube comprising a plurality of ports, the
at least one microchannel tube extending from the at least one
manifold, the plurality of ports each having a width and a height;
at least one fin extending from the at least one manifold and
arranged between the at least one microchannel tube and a second
microchannel tube; a refrigerant arranged to flow through the
microchannel tube; and wherein at least one port of the plurality
of ports has a cross-section area less than 0.35 millimeters
squared..
16. The HVAC system of claim 15, wherein at least one of the
plurality of ports has an aspect ratio greater than 1.5.
17. The HVAC system of claim 15, wherein at least one of the
plurality of ports has a height less than 0.6 millimeters.
18. The HVAC system of claim 15, wherein at least one of the
plurality of ports has an aspect ratio of approximately 1.0, a
height less than 0.5 millimeters, and a width less than 0.5
millimeters.
19. The HVAC system of claim 15, further comprising a fan, the fan
arranged to blow air across the at least one fin.
20. The HVAC system of claim 15, further comprising a low global
warming potential (low-GWP) refrigerant.
Description
TECHNICAL FIELD
[0001] This disclosure relates generally to a heating, ventilation,
and air conditioning (HVAC) system. More specifically, this
disclosure relates to an improved microchannel heat exchanger.
BACKGROUND
[0002] HVAC systems can be used to regulate the environment within
an enclosed space. Various types of HVAC systems, such as
residential and commercial, may be used to provide cool air, for
example during hot times of the year, and/or provide heat, for
example, during cooler times of the year. Providing heating and/or
cooling may be important for user comfort levels. If adequate
heating and/or cooling is not provided, a user may be uncomfortable
in the enclosed space. In HVAC systems, a condenser cools
refrigerant by heat exchange with ambient air drawn or blow across
a condenser coil by a fan. Microchannel heat exchangers may be used
within the condenser to sufficiently cool the refrigerant. Current
microchannel heat exchanger designs are limited.
SUMMARY
[0003] In certain embodiments, a microchannel heat exchanger
includes at least one manifold and at least one a microchannel
tube. The microchannel tube includes a plurality of ports, and the
microchannel tube extends from the at least one manifold. The
plurality of ports each have a width and a height. The microchannel
heat exchanger further includes at least one fin extending from the
at least one manifold. The fins are arranged between the at least
one microchannel tube and a second microchannel tube. The
microchannel heat exchanger further includes a refrigerant arranged
to flow through the microchannel tube. At least one port of the
plurality of ports has a cross-section area less than 0.35
millimeters squared.
[0004] In some embodiments, a condenser includes an enclosure and a
microchannel heat exchanger enclosed within the enclosure. The
microchannel heat exchanger includes at least one manifold and at
least one a microchannel tube. The microchannel tube includes a
plurality of ports, and the microchannel tube extends from the at
least one manifold. The plurality of ports each have a width and a
height. The microchannel heat exchanger further includes at least
one fin extending from the at least one manifold. The fins are
arranged between the at least one microchannel tube and a second
microchannel tube. The microchannel heat exchanger further includes
a refrigerant arranged to flow through the microchannel tube. At
least one port of the plurality of ports has a cross-section area
less than 0.35 millimeters squared.
[0005] In certain embodiments, a heating, ventilation, and air
conditioning (HVAC) system includes a condenser and a microchannel
heat exchanger. The microchannel heat exchanger includes at least
one manifold and at least one a microchannel tube. The microchannel
tube includes a plurality of ports, and the microchannel tube
extends from the at least one manifold. The plurality of ports each
have a width and a height. The microchannel heat exchanger further
includes at least one fin extending from the at least one manifold.
The fins are arranged between the at least one microchannel tube
and a second microchannel tube. The microchannel heat exchanger
further includes a refrigerant arranged to flow through the
microchannel tube. At least one port of the plurality of ports has
a cross-section area less than 0.35 millimeters squared.
[0006] Certain embodiments of the present disclosure may provide
one or more technical advantages. For example, increasing the
aspect ratio of ports of a microchannel tube increases the tubeside
heat transfer coefficient, and provides for better cooling for a
refrigerant with low global warming potential (low-GWP
refrigerant).
[0007] In certain embodiments where the aspect ratios is close to
one, the decrease in the cross-section area increases the heat
transfer rate due to higher refrigerant velocities.
[0008] In some embodiments, reducing the cross-section area of the
ports results in increased heat transfer rates, which are
beneficial for low-GWP refrigerants and may reduce the width of the
condenser tubes.
[0009] As another example, reducing the port width compared to
convention microchannel tubes, and maintaining fixed port height
(as shown in FIG. 3B), may allow a low-GWP refrigerant flowing
through a microchannel tube to transfer as much or more heat than a
conventional refrigerant flowing through a conventional
microchannel tube (e.g., in FIG. 3A). Consequently, a condenser
with the same or lower size and weight can be used for applications
involving the use of low GWP refrigerants.
[0010] As additional example, reducing both the height and the
width of the ports of microchannel tubes (e.g., FIG. 3C) reduces
the cross-section area of the port, and the refrigerant velocity
increases, which increases the tubeside heat transfer coefficient.
Another advantage of this embodiment is the reduction in airside
pressure drop due to the reduced tube height, resulting in reduced
fan power consumption. This embodiment may allow for increased
condenser heat rejection per unit area.
[0011] As another example, using smaller ports for microchannel
tubes allows a microchannel heat exchanger with a low-GWP
refrigerant to maintain the effectiveness of a microchannel heat
exchanger with a conventional refrigerant, without increasing the
size, weight, cost, or complexity of the microchannel heat
exchanger. Certain embodiments of the disclosure may include none,
some, or all of the above technical advantages. One or more other
technical advantages may be readily apparent to one skilled in the
art from the figures, descriptions, and claims included herein.
Moreover, while specific advantages have been enumerated above,
various embodiments may include all, some, or none of the
enumerated advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a more complete understanding of the present disclosure,
reference is now made to the following description, taken in
conjunction with the accompanying drawings, in which:
[0013] FIG. 1 is a diagram illustrating an example microchannel
heat exchanger, according to some embodiments;
[0014] FIG. 2 is a diagram illustrating an example microchannel
heat exchanger, according to some embodiments;
[0015] FIGS. 3A, 3B, and 3C illustrate example microchannel tubes,
according to some embodiments; and
[0016] FIG. 4 is a diagram illustrating outdoor an HVAC unit
comprising a microchannel heat exchanger.
DETAILED DESCRIPTION
[0017] Microchannel heat exchangers may consist of several tubes,
with each tube containing multiple ports that the refrigerant may
flow through. Traditionally, microchannel heat exchangers have been
used with a conventional refrigerant (e.g., hydrofluorocarbons such
as R-410A), which have significant global warming potential (GWP)
when released into the atmosphere. As companies continue to
emphasize global warming mitigation, new refrigerants with low
global warming potential (low-GWP refrigerants) are being
integrated into existing HVAC systems. HVAC systems may use
microchannel heat exchangers as condensers. Due to the poor
condensing heat transfer characteristics of low GWP refrigerants,
it may be necessary to increase the surface area of the heat
exchangers. For example, low-GWP refrigerants may have lower
specific heat, lower enthalpy, and/or lower
evaporation/condensation heat transfer coefficients. Further,
current microchannel heat exchangers have a narrow range of port
sizes that are not well suited to these new, low-GWP refrigerants.
Thus, heat transfer occurs at a reduced rate in these low-GWP
refrigerants. Increasing the size of the microchannel heat
exchanger using a low GWP refrigerant, may provide the same system
performance as with a conventional refrigerant. However increasing
the size further increases cost, expense, and space required to
house the microchannel heat exchanger, while further requiring
additional fan power consumption, thus reducing the system
efficiency. Thus, there is a need for a microchannel heat exchanger
design that increases the tubeside heat transfer coefficient, to
compensate for the poor thermal properties associated with low-GWP
refrigerant.
[0018] This disclosure recognizes that an improved microchannel
heat exchanger using refrigerants with poor thermal properties may
include an increased number of ports in a microchannel tube, a
reduced port hydraulic diameter, a reduced port cross-section area,
and an increased aspect ratio of the ports due to reduction in the
width. This improved microchannel heat exchanger may facilitate
increasing the heat transfer coefficient of the microchannel heat
exchanger, in some embodiments. This improvement creates a more
compact and efficient microchannel heat exchanger for low-GWP
refrigerants.
[0019] Embodiments of the present disclosure and its advantages are
best understood by referring to FIGS. 1 through 4 of the drawings,
like numerals being used for like and corresponding parts of the
various drawings.
[0020] FIG. 1 is a diagram illustrating example microchannel heat
exchanger 101 according to some embodiments. Microchannel heat
exchanger 101 comprises manifolds 140, a plurality of microchannel
tubes 110, and a plurality of fins 120.
[0021] Microchannel heat exchanger 101 comprises manifold 140 and
141. Manifolds 140 and 141 may be in communication with the overall
air-conditioning system. Manifold 140 introduces refrigerant to
microchannel heat exchanger 101 through inlet tubing (e.g., flow
191) and releases refrigerant from microchannel heat exchanger 101
through outlet tubing (e.g., flow 194). Although manifolds 140 and
141 are shown of a cylindrical configuration, they may be of a
rectangular, half of a cylinder or any other shape, as well as have
a single chamber or multi-chamber design, depending on the
refrigerant path arrangement.
[0022] Microchannel tubes 110 are generally elongated and
substantially flat, and extend from one or more manifolds 140,
providing a path for refrigerant to flow. Each microchannel tube
110 has a first end mounted to manifold 140 and a second end
mounted to manifold 141, and at least one flow channel extending
longitudinally, thereby providing a flow path between manifold 140
and manifold 141. Microchannel tubes 110 generally extend in a
horizontal direction between manifolds 140, providing a plurality
of parallel refrigerant flow paths between manifolds 140. Each
microchannel tube 110 may include any number of ports within. In
some embodiments, microchannel tubes may be made of aluminum. The
heat exchanger refrigerant pass arrangement may be of a multi-pass
configuration, such as depicted in FIG. 1, or of a single-pass
configuration, depending on particular application
requirements.
[0023] A plurality of fins 120 may be arranged between microchannel
tubes 110, and parallel to each other. Fins 120 extend from
microchannel tubes 110 such that the surface area is increased and
configured to transfer heat efficiently. Fins 120 may be straight
or angled. Fins 140 may have flat, wavy, corrugated or louvered
design and typically form triangular, rectangular, offset or
trapezoidal airflow passages. In operation, air may below across
fins 120 in order to remove heat from refrigerant flowing through
microchannel tubes 110.
[0024] In operation, a refrigerant flows through microchannel tubes
110 in various directions. Refrigerant may be introduced to
microchannel heat exchanger 101 at manifold 140 through flow 191.
The refrigerant may split such that a portion flows through one or
more microchannel tubes 110 until it reaches manifold 140 at flow
192. As it flows through microchannel tubes 110, fins 120
facilitate a heat transfer such that the refrigerant is cooled. The
refrigerant continues to flow 193 in manifold 141 where the
refrigerant again may split such that a portion flows through one
or more microchannel tubes 110 from flow 193 to flow 194 at
manifold 140. At flow 194, refrigerant then exits microchannel heat
exchanger 101. After completing its flow through microchannel heat
exchanger 101 at flow 194, refrigerant may be cooled to a lower
temperature than when it entered microchannel heat exchanger 101 at
flow 191.
[0025] Modifications, additions, or omissions may be made to the
systems described herein without departing from the scope of the
disclosure. For example, microchannel heat exchanger 101 may
include any number of manifolds 140, microchannel tubes 110, and
fins 120. The components may be integrated or separated. Moreover,
the operations may be performed by more, fewer, or other
components. FIG. 2 is a diagram illustrating example microchannel
heat exchanger 201, according to some embodiments. In some
embodiments, manifolds 240 and 241 operate as manifolds 140 and 141
of FIG. 1. In some embodiments, microchannel tubes 210 and fins 220
operate as microchannel tubes 110 and fins 120 of FIG. 1. Ports 230
may be individual channels of microchannel tube 210, providing a
path for refrigerant to flow through microchannel tube 210 from
manifold 240 to manifold 241. Microchannel tubes 210 may include
any number of ports 230. As the size of ports 230 varies, the size
of microchannel tubes 210 may increase or decrease, thus affecting
the number of required microchannel tubes 210 in a microchannel
heat exchanger (e.g., microchannel heat exchanger 101 of FIG. 1),
in order to sufficiently cool the refrigerant.
[0026] FIGS. 3A, 3B, and 3C illustrate example microchannel tubes
310a, 310b, and 310c, according to some embodiments. In some
embodiments, microchannel tubes 310a-c may be similar to
microchannel tubes 110 and 210 of FIG. 1 and FIG. 2, respectively.
For example, refrigerant may flow through microchannel tubes 310a-c
using ports 330a-c from one manifold to another in order to
transfer heat from the refrigerant.
[0027] In FIG. 3A, microchannel tube 310a represents an embodiment
used in a microchannel heat exchanger with conventional
refrigerant. Port 330a has height 331a and width 331b. The aspect
ratio of port 330a is height 331a divided by width 331b. For
example, the aspect ratio of port 330 may range from 0.4-1.8, with
width 331b ranging from 0.50 mm-1.9 mm, height 331a ranging from
0.50 mm-1.40 mm, and cross-section areas ranging from 0.35
mm.sup.2-1.4 mm.sup.2.
[0028] This disclosure recognizes that an improved microchannel
heat exchanger may alter the microchannel ports to provide a more
efficient heat transfer. The improved microchannel heat exchanger
of this disclosure may reduce the width, height, port cross-section
area (i.e. width times height), and/or increased aspect ratio of
the ports. In some embodiments, the width of a port may be reduced.
In certain embodiments, the height of the port may be reduced. In
some embodiments, both the width and the height of the ports may be
reduced. Reducing the width, height, or both the width and the
height of the ports (e.g., compared to a convention microchannel
heat exchanger) creates a smaller cross-section area of the port.
This improved microchannel heat exchanger may facilitate increasing
the heat transfer coefficient of the microchannel heat exchanger,
in some embodiments. This improvement creates a more compact and
efficient microchannel heat exchanger for low-GWP refrigerants.
[0029] Reducing the cross-section area of the port in a traditional
microchannel heat exchanger would not provide similar benefits when
using traditional refrigerants. Microchannel heat exchangers may be
air-cooled and therefore may have a high airside thermal
resistance. The overall heat transfer coefficient of the
microchannel heat exchanger is a function of the airside convection
coefficient, which is usually the lowest, the effective conduction
heat transfer coefficient, which is typically the highest, and the
refrigerant side heat transfer coefficient. Specifically, the heat
transfer coefficient for traditional refrigerants is high enough,
such that further reduction in the cross-section area of the port
would not significantly increase the overall heat transfer
coefficient of the traditional microchannel heat exchanger.
Further, creating a smaller cross-section area would create a
pressure drop, such that the compressor requires more power, and
the system efficiency decreases. The improved microchannel heat
exchanger of this disclosure uses a refrigerant with low thermal
properties and a low heat transfer coefficient. Thus, reducing the
cross-section area of the port would provide a significant increase
in the heat transfer coefficient, thus resulting in a more compact
condenser and providing a more efficient system because the airside
pressure drop across the coil is lower, which may reduce the fan
power required. FIGS. 3B and 3C illustrate improved microchannel
heat exchangers, according to some embodiments. These embodiments
are illustrative rather than limiting in nature, and a wide range
of variations, modifications, changes, and substitutions may be
contemplated.
[0030] In FIG. 3B, microchannel tube 310b may be an embodiment of
the present disclosure, where the width of ports may be reduced to
compensate for the low-GWP refrigerant's poor thermal qualities. In
some embodiments, microchannel tube 310b includes ports 330b. Port
330b may have width 332b ranging from 0.3 mm-0.6 mm and height 331b
ranging from 0.3 mm-0.6 mm. Port 330b may include any combination
of width 332 and height 331b. In some embodiments, port 330b has a
smaller width 332b than width 332a of port 330a, thus creating a
more rectangular shape for port 330b than port 330a. For example,
port 330b may have width 331b of 0.3 mm, 0.4 mm, or 0.5 mm. In this
example, height 331b may remain the same or lesser than the height
shown in 331a (e.g., 0.50 mm-1.4 mm). Creating thinner ports 330b
increases the number of ports 330b that may fit within microchannel
tube 310b. Also, reducing width 331b may increase the aspect ratio
of port 330b. In some embodiments, the port cross-section areas are
lower than 330a. For example, the aspect ratio of port 330b may be
1.0-1.80 or higher and areas may range between 0.09 mm.sup.2 and
0.25 mm.sup.2. Reducing the cross-section areas of ports 330b may
reduce the hydraulic diameter of port 330b, which may increase the
tubeside heat transfer coefficient, and provide for better heat
transfer with a low-GWP refrigerant. Thus, by reducing width 331b,
a low-GWP refrigerant flowing through microchannel tube 310b may
transfer as much heat as a conventional refrigerant flowing through
microchannel tube 310a.
[0031] In FIG. 3C, microchannel tube 310c may be an embodiment of
the present disclosure, where the width and height of ports may be
reduced to compensate for the low-GWP refrigerant's poor thermal
qualities. In some embodiments, microchannel tube 310b includes
ports 330b. Port 330b may have width 332b ranging from 0.3 mm-0.6
mm and height 331b ranging from 0.3 mm-0.6 mm. Port 330b may
include any combination of width 332 and height 331b. In some
embodiments, port 330c has a smaller width 332c than width 332a of
port 330a and a smaller height 331c than height 331a of port 330a.
By reducing both height 331c and width 332a of port 330c, the
velocity of the refrigerant increases, which may also increase the
heat transfer coefficient, and allow the low-GWP refrigerant to
cool more quickly. Also, by reducing both height 331c and width
332a of port 330c, additional ports 330c may be included in
microchannel tube 310c than microchannel tube 310a. In some
embodiments, even when reducing both height 331c and width 332a,
port 330c may remain close to a square shape, (e.g., 0.5 mm by 0.5
mm, 0.55 mm by 0.45 mm, 0.29 mm by 0.31 mm), and the aspect ratio
of port 330c may remain approximately 1.0 (e.g., 0.8-1.2). By
reducing the cross-section area, the velocity of the refrigerant
increases, which increases the heat transfer coefficient, and
allows the low-GWP refrigerant to cool more quickly. The smaller
ports (e.g., ports 330b-c) allow a microchannel heat exchanger with
a low-GWP refrigerant to maintain the same effectiveness as a
microchannel heat exchanger with a conventional refrigerant without
increasing the size, weight, cost, or complexity. In some
embodiments, arranging ports 330b and 330c as described in this
disclosure would have limited impact on the tubeside resistance of
a microchannel heat exchanger using conventional refrigerant. The
change in size of ports 330b and 330c from 330a may only increase
the heat transfer coefficient of a conventional refrigerant by a
nominal amount. In general, air-cooled condensers have a higher
heat transfer resistance on the airside. In air-cooled condensers
using conventional refrigerants the tubeside resistance is lower,
and the air side resistance is dominant, so even if the heat
transfer coefficient of the refrigerant is increased slightly, the
air cannot absorb enough heat to affect the actual cooling of the
conventional refrigerant. However, with low-GWP refrigerants, the
tubeside resistance is higher and an increase in the tubeside heat
transfer coefficient may greatly impact the actual cooling of the
low-GWP refrigerant. Thus, providing ports with higher aspect
ratios (e.g., ports 330b), or smaller ports with aspect ratios
close to 1.0 (e.g., ports 330c), low-GWP refrigerants may perform
cooling as effectively as a conventional refrigerant in the same
type and size of microchannel heat exchanger.
[0032] In some embodiments, ports 330c are a smaller size (e.g.,
compared to ports 330a) such that microchannel tube 310c may also
be reduced in height (e.g., compared to the height of microchannel
tube 310a). By reducing the height of microchannel tube 310c,
microchannel heat exchanger (e.g., microchannel heat exchanger 101
of FIG. 1) may be made with fewer materials, thus conserving
resources and expense. By reducing the height of microchannel tube
310c, microchannel heat exchanger (e.g., microchannel heat
exchanger 101 of FIG. 1), may include fins (e.g., fins 120 of FIG.
1) with an increased height. Larger fins may increase the surface
area on which air is blowing, thus increasing the heat transfer and
providing better cooling for the low-GWP refrigerant. Also, by
reducing the height of microchannel tube 310c, microchannel heat
exchanger (e.g., microchannel heat exchanger 101 of FIG. 1) may
include additional tubes (e.g., tubes 110) to create additional
pathways for the low-GWP refrigerant to flow through, and thus
increasing the amount heat transfer.
[0033] FIG. 4 is a diagram illustrating outdoor HVAC unit or
condenser 401 comprising a microchannel heat exchanger 101 of FIG.
1. Outdoor unit 401 may encase microchannel heat exchanger 101 in
an enclosure such that it is protected from an external
environment. In some embodiments, outdoor unit 401 may further
comprise fan 405. Fan 405 may direct a flow of air across
microchannel heat exchanger. Fan 405 provides air flow to
microchannel heat exchanger 101 to facilitate cooling the
refrigerant flowing through microchannel heat exchanger 101. Any
number of fans may be included.
[0034] In some embodiments, microchannel heat exchanger 101 may
incorporate ports 330b and/or 330c from FIG. 3. By incorporating
smaller ports 330b and/or 330c than ports 330a, heat is transferred
from the low-GWP refrigerant more efficiently. Thus, fan 405 may
consume less power for a given air flow. With fan 405 consuming
less power, outdoor HVAC unit 401 operates more efficiently, and
conserves resources.
[0035] Modifications, additions, or omissions may be made to the
systems, apparatuses, and methods described herein without
departing from the scope of the disclosure. The components of the
systems and apparatuses may be integrated or separated. Moreover,
the operations of the systems and apparatuses may be performed by
more, fewer, or other components. For example, microchannel heat
exchanger 101 may include any number of microchannel tubes 110,
fins 120, manifolds 140 and 141, and so on, as performance demands
dictate. One skilled in the art will also understand that
microchannel heat exchanger 101 and outdoor HVAC unit 401 can
include other components that are not illustrated but are typically
included with HVAC systems.
[0036] Although this disclosure has been described in terms of
certain embodiments, alterations and permutations of the
embodiments will be apparent to those skilled in the art, and it is
intended that the present disclosure encompass such changes,
variations, alterations, transformations, and modifications as fall
within the scope of the appended claims. Accordingly, the above
description of the embodiments does not constrain this disclosure.
Other changes, substitutions, and alterations are possible without
departing from the spirit and scope of this disclosure.
* * * * *