U.S. patent application number 12/072280 was filed with the patent office on 2009-08-27 for heat and mass exchanger liquid line subcooler.
Invention is credited to Lindsey Lee Leitzel, Ilya Reyzin, Edward Wolfe, IV.
Application Number | 20090211293 12/072280 |
Document ID | / |
Family ID | 40996997 |
Filed Date | 2009-08-27 |
United States Patent
Application |
20090211293 |
Kind Code |
A1 |
Wolfe, IV; Edward ; et
al. |
August 27, 2009 |
Heat and mass exchanger liquid line subcooler
Abstract
An air conditioning system for circulating a refrigerant
includes a condenser having a vapor inlet for condensing the
refrigerant into a high-pressure liquid having a first
predetermined temperature. A heat exchanger including an exhaust
channel directs air therethrough. The heat exchanger further
includes a refrigerant inlet in fluid communication with a
refrigerant outlet for receiving a high-pressure liquid and for
delivering the high-pressure liquid therethrough. Furthermore, a
heat mass exchanger outputs wet working air having a second
predetermined temperature. The heat exchanger is in fluid
communication with the heat mass exchanger for receiving the
working air having a temperature less than the high-pressure
liquid. The working air flows through the exhaust channel and over
the high-pressure liquid to transfer heat from the high-pressure
liquid to the working air for reducing the temperature of the
high-pressure liquid.
Inventors: |
Wolfe, IV; Edward; (Amherst,
NY) ; Reyzin; Ilya; (Williamsville, NY) ;
Leitzel; Lindsey Lee; (Lockport, NY) |
Correspondence
Address: |
DELPHI TECHNOLOGIES, INC.
M/C 480-410-202, PO BOX 5052
TROY
MI
48007
US
|
Family ID: |
40996997 |
Appl. No.: |
12/072280 |
Filed: |
February 25, 2008 |
Current U.S.
Class: |
62/498 ; 62/180;
62/502; 62/506; 62/513 |
Current CPC
Class: |
F24F 13/222 20130101;
F25B 40/02 20130101; F25B 2339/041 20130101 |
Class at
Publication: |
62/498 ; 62/502;
62/506; 62/513; 62/180 |
International
Class: |
F25B 1/00 20060101
F25B001/00 |
Claims
1. An air conditioning system for circulating a refrigerant to
thermally condition ambient air introduced into the air
conditioning system comprising; a condenser including a liquid
outlet and a vapor inlet for receiving the refrigerant to condense
the refrigerant into a high-pressure liquid having a first
predetermined temperature, a heat exchanger having an exhaust air
inlet and an exhaust air outlet and an exhaust channel extending
from said exhaust air inlet to said exhaust air outlet for
directing air therethrough, said heat exchanger having a
refrigerant inlet in fluid communication with a refrigerant outlet
for receiving the high-pressure liquid and for delivering the
high-pressure liquid therethrough, a heat mass exchanger having a
plurality ambient air inlets for receiving ambient air and a
plurality of working air outlets for outputting wet working air
having a second predetermined temperature and a plurality of air
channels for conveying air from said ambient air inlets to said
working air outlets, said heat exchanger in fluid communication
with said heat mass exchanger for receiving the working air having
a temperature less than the high-pressure liquid from said
condenser and flowing the working air through said exhaust channel
and over the high-pressure liquid to transfer heat from the
high-pressure liquid to the working air for reducing the
temperature of the high-pressure liquid.
2. An air conditioning system as set forth in claim 1 wherein said
exhaust air inlet of said heat exchanger is disposed against said
heat mass exchanger and in fluid communication with said working
air outlets.
3. An air conditioning system as set forth in claim 1 wherein said
heat mass exchanger includes walls having apertures and being
spaced and parallel from each other and extending from said ambient
air inlets to said working air outlets and being enclosed by a top
and a base to define said plurality of air channels for splitting
said ambient air into said wet working air.
4. An air conditioning system as set forth in claim 3 wherein said
air channels include alternating dry channels extending from one of
said ambient air inlets and being closed at the rear ends for
flowing dry air therethrough and including wet channels disposed
between said dry channels and being closed at the front ends and
extending to one of said working air outlets for flowing wet air
therethrough.
5. An air conditioning system as set forth in claim 4 further
comprising a first plurality of said dry channels having said
apertures in said walls thereof for conveying air out of a
corresponding said dry channel and into at least one adjacent wet
channel to cool the air in said adjacent dry channel.
6. An air conditioning system as set forth in claim 5 further
comprising a second plurality of said dry channels alternating with
said first plurality of dry channels and disposed between two of
said wet channels and having a plurality of product air outlets in
said tops thereof for conveying pre-cooled product air from said
second plurality of alternating dry channels.
7. An air conditioning system as set forth in claim 6 further
comprising a wicking material lining each of said wet channels for
retaining a liquid to be evaporated in response to airflow conveyed
by said apertures in said walls of said dry channels for extracting
heat from said adjacent dry channels to generate the dry air in
said adjacent dry channels.
8. An air conditioning system as set forth in claim 7 further
comprising a reservoir for collecting liquid and for supplying
liquid to said wicking material of each of said wet air channels to
wet said wicking material.
9. An air conditioning system as set forth in claim 1 further
comprising a compressor including a high pressure outlet in fluid
communication with said liquid-vapor inlet of said condenser and a
low pressure inlet for receiving the refrigerant being in a
low-pressure heated vapor state and for compressing the refrigerant
from a low-pressure heated vapor into a high-pressure superheated
vapor.
10. An air conditioning system as set forth in claim 9 further
comprising a valve including a valve inlet having an inlet diameter
and being in fluid communication with said refrigerant outlet of
said heat exchanger for receiving the high-pressure liquid and
including a valve outlet having an outlet diameter greater than
said inlet diameter for decreasing the pressure of the
high-pressure liquid to transform the refrigerant from the
high-pressure liquid into a cool low-pressure mixed liquid-vapor in
response to the high-pressure liquid flowing from said valve inlet
to said valve outlet.
11. An air conditioning system as set forth in claim 10 further
comprising an evaporator including a liquid-vapor inlet for
receiving the mixed liquid-vapor and a low-pressure outlet for
outputting the low-pressure heated vapor and including a
refrigerant channel extending between said liquid-vapor inlet and
said low-pressure outlet for delivering the mixed liquid-vapor
therethrough.
12. An air conditioning system as set forth in claim 11 wherein
said evaporator includes a conditioned air outlet and a product air
inlet in fluid communication with said product air outlets of said
heat mass exchanger for receiving the pre-cooled product air from
said heat mass exchanger air having a temperature greater than the
temperature of the mixed liquid-vapor.
13. An air conditioning system as set forth in claim 12 including
an air pathway extending perpendicular to said refrigerant channel
from said product air inlet to said conditioned air outlet for
flowing the pre-cooled air over the mixed liquid-vapor for
transferring heat from the pre-cooled air to the mixed liquid-vapor
to generate cool conditioned air having a temperature less than the
temperature of the pre-cooled air thereby generating condensate in
response to the pre-cooled air flowing over the mixed
liquid-vapor.
14. An air conditioning system as set forth in claim 12 wherein
said evaporator includes a drain disposed at the bottom of said
evaporator and being fluid communication with said heat mass
exchanger for draining the condensate from said evaporator to said
heat mass exchanger for supplying the condensate to said wicking
material of each of said wet air channels.
15. An air conditioning system as set forth in claim 9 further
comprising a first conduit having one end connected to said
high-pressure outlet of said compressor and an opposite end
connected to said vapor inlet of said condenser for delivering the
refrigerant being in a high-pressure superheated vapor state from
said compressor to said condenser.
16. An air conditioning system as set forth in claim 1 further
comprising a second conduit having one end connected to said liquid
outlet of said condenser and an opposite end connected to said
refrigerant inlet of said heat exchanger for delivering the
high-pressure liquid from said condenser to said heat
exchanger.
17. An air conditioning system as set forth in claim 10 further
comprising a third conduit having one end connected to said
refrigerant outlet of said heat exchanger and an opposite end
connected to said valve inlet for delivering the high-pressure
liquid from said heat exchanger to said valve.
18. An air conditioning system as set forth in claim 11 further
comprising a fourth conduit having one end connected to said valve
outlet and an opposite end connected to said liquid-vapor inlet of
said evaporator for delivering the mixed liquid-vapor from said
valve to said evaporator.
19. An air conditioning system as set forth in claim 11 further
comprising a fifth conduit having one end connected to said low
pressure outlet of said evaporator and having an opposite end
connected to said low-pressure inlet of said compressor for
returning the low-pressure vapor to said compressor.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The subject of the invention relates generally to the
conditioning of air, and more specifically, to improving the heat
transfer efficiency of an air conditioning system.
[0003] 2. Description of the Prior Art
[0004] Traditional air conditioning systems utilize the
vapor-compression refrigeration cycle to condition ambient air into
cool air for cooling a surrounding area. The traditional air
conditioning system operating in the vapor-compression
refrigeration cycle typically includes a compressor, a condenser, a
heat exchanger, and an evaporator for transforming the refrigerant
from a low pressure heated vapor into a cool mixed liquid-vapor. As
air flows over the mixed liquid-vapor, heat from the air is
transferred to the mixed liquid-vapor refrigerant to produce cool
conditioned air that may be utilized to cool the surrounding area.
The heat transferred to the refrigerant vaporizes the remaining
liquid in the mixed-liquid vapor resulting in a low pressure heated
vapor. This low pressure heated vapor is returned to the compressor
to complete the refrigeration cycle. A thermal expansion valve may
also be disposed downstream for decreasing the pressure of the
refrigerant prior to delivery into the evaporator. By decreasing
the pressure of the refrigerant, the remaining liquid can be
vaporized more easily.
[0005] The thermodynamic characteristics of a typical refrigerant
are illustrated by the pressure-enthalpy diagram shown if FIG. 1.
The P-h plane is useful in showing the amounts of energy transfer
as heat. Referring to FIG. 1, saturated vapor at low pressure
enters the compressor and undergoes a reversible adiabatic
compression in process 1-2, i.e. a compression which results in no
gain or loss of heat. Heat is then rejected at constant pressure in
process 2-3. An adiabatic pressure change occurs through the
expansion device in process 3-4. The working fluid is then
evaporated at constant pressure in process 4-1 to complete the
refrigeration cycle.
[0006] Today, energy used to generate cool conditioned air has
become increasingly important. Air conditioning systems are seen as
large consumers of power. Therefore, energy efficient air
conditioning has become an important area of investigation. Some
current investigations have focused on liquid line cooling using
the suction line cooling capacity; however, these systems do not
reduce energy input. Instead, they merely increase cooling
capacity.
SUMMARY OF THE INVENTION AND ADVANTAGES
[0007] In addition to the structure described above, the invention
provides for the heat exchanger in fluid communication with the
heat mass exchanger for receiving wet working air having a
temperature less than the temperature of the high-pressure liquid
from the condenser. The working air generated by a heat mass
exchanger is flowed through the heat exchanger and over the
high-pressure liquid to transfer heat from the high-pressure liquid
to the working air for reducing the temperature of the
high-pressure liquid.
[0008] Accordingly, the evaporative capacity of the evaporator is
increased and the overall heat transfer efficiency of the air
conditioning system is improved. Additionally, the system leverages
the wet working air instead of simply exhausting the working air
into the atmosphere to further promote an efficient air
conditioning system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Other advantages of the present invention will be readily
appreciated, as the same becomes better understood by reference to
the following detailed description when considered in connection
with the accompanying drawings wherein:
[0010] FIG. 1 is a pressure enthalpy diagram representing the
refrigeration process;
[0011] FIG. 2 is a hardware schematic of the air conditioning
system according the present invention;
[0012] FIG. 3 is an isometric view of a heat mass exchanger
according to the present invention; and
[0013] FIG. 4 is an isometric view of a heat exchanger disposed
against the heat mass exchanger according to the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Referring to FIGS. 2-4, wherein like numerals indicate
corresponding parts throughout the several views, an air
conditioning system 20 for circulating a refrigerant to thermally
condition ambient air introduced into the air conditioning system
20 is generally shown. FIG. 2 shows the air conditioning system 20
including a compressor 22, a condenser 24, a heat exchanger 26, a
valve 28, and an evaporator 30 for completing the thermal vapor
compression refrigeration cycle that transforms the refrigerant
from a low pressure heated vapor into a cool mixed
liquid-vapor.
[0015] The refrigeration cycle beings at the compressor 22
generally indicated. The compressor 22 includes a low-pressure
inlet 32 and a high-pressure outlet 34. The compressor 22 receives
the refrigerant in a low-pressure heated vapor state and compresses
the refrigerant into a high-pressure superheated vapor where it is
output from the high-pressure outlet 34.
[0016] The condenser 24 generally indicated has a vapor inlet 36
for receiving the refrigerant in a high-pressure heated vapor state
and a liquid outlet 38. As the high-pressure heated vapor enters
the vapor inlet 36 and flows to the liquid outlet 38, the
high-pressure superheated vapor is condensed into a high-pressure
liquid having a first predetermined temperature.
[0017] The heat exchanger 26 generally indicated has an exhaust air
inlet 40 for receiving air and an exhaust air outlet 42. An exhaust
channel 44 extends from the exhaust air inlet 40 to the exhaust air
outlet 42 for directing the air therethrough. The heat exchanger 26
also has a refrigerant inlet 46 for receiving the high-pressure
liquid and a refrigerant outlet 48. The heat exchanger 26 further
includes a refrigerant tube 50 having a cross-section defining flat
sides and rounded ends. The refrigerant tube 50 extends into the
exhaust channel 44 from the refrigerant inlet 46 to the refrigerant
outlet 48 through a plurality of U-shapes to form a serpentine
pattern for delivering the high-pressure liquid from the
refrigerant inlet 46 to the refrigerant outlet 48.
[0018] A valve 28, such as a thermal expansion valve 28, is
generally indicated and is disposed between the heat exchanger 26
and the evaporator 30. The thermal expansion valve 28 includes a
valve inlet 52 having an inlet diameter d.sub.INLET and a valve
outlet 54 having an outlet diameter d.sub.OUTLET greater than the
inlet diameter d.sub.INLET. The valve inlet 52 is in fluid
communication with the condenser 24 for receiving the high-pressure
liquid. As the high-pressure liquid flows from the valve inlet 52
to the valve outlet 54, the pressure of the high-pressure liquid is
decreased and the refrigerant transforms from a high-pressure
liquid into a cool low-pressure mixed liquid-vapor. By decreasing
the pressure of the refrigerant prior to delivery into the
evaporator 30, vaporization of the remaining liquid is improved. It
is also appreciated that although a thermal expansion valve 28 is
described, another thermal expansion device and/or valve 28 that
decreases the pressure and/or temperature of the refrigerant may
used.
[0019] The refrigerant cycle ends at the evaporator 30 generally
indicated. The evaporator 30 includes a liquid-vapor inlet 56 for
receiving the mixed liquid-vapor and a low-pressure outlet 58 for
outputting low-pressure heated vapor. A refrigerant channel 60 is
included and extends between the liquid-vapor inlet 56 and the
low-pressure outlet 58 for delivering the mixed liquid-vapor
therethrough. The evaporator 30 includes a product air inlet 62 for
receiving air and a conditioned air outlet 64. An air pathway 66
extends perpendicular to the refrigerant channel 60 from the
product air inlet 62 to the conditioned air outlet 64 for conveying
air over the mixed liquid-vapor. As air flows over the mixed
liquid-vapor, heat is transferred from the air to the refrigerant.
In response, liquid from the mixed liquid-vapor refrigerant
evaporates and the refrigerant is transformed into a high-pressure
heated vapor, which is returned to the condenser 24 to complete the
refrigeration cycle. Additionally, by transferring heat from the
air flowing over the refrigerant, the cool conditioned air is
generated. Furthermore, condensate is generated in response to air
flowing over the mixed liquid-vapor. The evaporator 30 may include
a drain 68 disposed at the bottom 70 of the evaporator 30 for
draining the condensate from the evaporator 30.
[0020] A plurality of conduits 72, 74, 76, 78, 80 are used to
connect the compressor 22, the condenser 24, the heat exchanger 26,
the valve 28, and the evaporator 30 to one another in order to
complete the air conditioning system 20. Although conduits 72, 74,
76, 78, 80 are described to connect the air conditioning system 20,
any means for providing fluid communication between each of the
compressor 22, the condenser 24, the heat exchanger 26 and the
valve 28 may be used. Specifically, a first conduit 72 is included
having one end connected to the high-pressure outlet 34 of the
compressor 22. The opposite end is connected to the vapor inlet 36
of the condenser 24 for delivering the high-pressure superheated
vapor from the compressor 22 to the condenser 24. A second conduit
74 is included having one end connected to the liquid outlet 38 of
the condenser 24. The opposite end is connected to the refrigerant
inlet 46 of the heat exchanger 26 for delivering the high-pressure
liquid from the condenser 24 to the heat exchanger 26. A third
conduit 76 is included having one end connected to the refrigerant
outlet 48 of the heat exchanger 26. The opposite end is connected
to the valve inlet 52 of the valve 28 for delivering the
high-pressure liquid from the heat exchanger 26 to the valve 28. A
fourth conduit 78 is included having one end connected to the valve
outlet 54. The opposite end is connected to the liquid-vapor inlet
56 of the evaporator 30 for delivering the mixed liquid-vapor from
the valve 28 to the evaporator 30. Lastly, a fifth conduit 80 is
included having one end connected to the low-pressure outlet 58 of
the evaporator 30. The opposite end is connected to the
low-pressure inlet 32 of the compressor 22 for returning the
refrigerant being in the low-pressure heated vapor state to the
compressor 22.
[0021] Traditionally, the air conditioning system 20 thermally
conditions ambient air to generate cool conditioned air utilized to
cool the surrounding area. However, it is generally understood that
the temperature of the air introduced into the evaporator 30 plays
an important role in the overall efficiency of the air conditioning
system 20. By reducing the temperature of the air prior to input
into the evaporator 30, the overall load on the evaporator 30 may
be reduced. Accordingly, a heat mass exchanger 82 may be used to
provide the air conditioning system 20 with pre-cooled product air.
By providing pre-cooled air to the air conditioning system 20, the
temperature of the conditioned air generated by the evaporator 30
is further decreased.
[0022] Referring to FIG. 3, the heat mass exchanger 82 is generally
shown having a plurality of ambient air inlets 84 for receiving
ambient air and a plurality of working air outlets 86 for
exhausting cooled wet working air. The heat mass exchanger 82
includes a plurality of spaced and parallel walls 88 closed by a
top 90 and a base 91 to define air channels 92 generally indicated
for directing airflow therein. The air channels 92 further include
alternating dry channels 94 extending from one of the ambient air
inlets 84 and being closed at the rear ends for flowing dry air
therethrough.
[0023] The air channels 92 also include wet channels 96 disposed
between the dry channels 94 and being closed at the front ends. The
wet channels 96 extend to one of the working air outlets 86 for
flowing wet air therethrough. A first plurality of the dry channels
94 have a plurality of apertures 98 in the walls 88 for conveying
air out of the respective dry channel 94 and into at least one
adjacent wet channel 96 to cool the air in the adjacent dry
channels 94. A second plurality of the dry channels 94 are included
alternating with the first plurality of dry channels 94. The second
plurality of dry channels 94 are disposed between two of the wet
channels 96 and have a plurality of product air outlets 100 in the
tops 90 thereof for directing pre-cooled product air from the
second plurality of alternating dry channels 94. Each of the wet
channels 96 are lined with a wicking material 102 for retaining a
liquid.
[0024] The liquid is evaporated in response to airflow conveyed by
the apertures 98 in the walls 88 of the dry channels 94 for
extracting heat from the adjacent dry channels 94, thereby
generating the dry air in the adjacent dry channels 94. The product
air inlet 62 of the evaporator 30 is in fluid communication with
the product air outlets 100 of the heat mass exchanger 82 for
receiving the pre-cooled product air and flowing the pre-cooled air
over the mixed liquid-vapor to generate the conditioned air from
the conditioned air outlet 64.
[0025] The heat mass exchanger 82 may further include a reservoir
104 in fluid communication with the drain 68 of the evaporator 30
for collecting the condensate. The reservoir 104 supplies the
condensate to the wicking material 102 of each of the wet air
channels to wet the wicking material 102. Although one embodiment
of a heat mass exchanger 82 is described above, any device for
cooling air while generating wet working air as a by-product of the
heat exchanging process may be used.
[0026] Traditionally, the wet working air generated by the heat
mass exchanger 82 was viewed as being too humid to be utilized and
was simply exhausted into the atmosphere. However, the air
conditioning system 20 is distinguished by providing a means of
flowing the wet working air exhausted from the heat mass exchanger
82 over the refrigerant flowing through the heat exchanger 26. The
wet working air exhausted from the heat exchanger 26 has a
temperature less than the high-pressure liquid from condenser 24,
which flows through the heat exchanger 26. To maximize the air flow
delivered to the high-pressure liquid flowing through the heat
exchanger 26, the exhaust air inlet 40 of the heat exchanger 26 is
disposed against the heat mass exchanger 82 and in fluid
communication with the working air outlets 86, as shown in FIG.
4.
[0027] Accordingly, the heat exchanger 26 receives the wet working
air having a temperature less than the high-pressure liquid from
the condenser 24. The wet working air flows through the exhaust
channel 44 and over the high-pressure liquid to transfer heat from
the high-pressure liquid to the working air for reducing the
temperature of the high-pressure liquid. Therefore, the evaporative
capacity of the evaporator 30 is increased and the overall
efficiency of the air conditioning system 20 is improved.
Additionally, the system leverages the wet working air generated by
the heat mass exchanger 82 instead of simply exhausting the working
air into the atmosphere, thereby further promoting an efficient air
conditioning system 20.
[0028] While the invention has been described with reference to an
exemplary embodiments, it will be understood by those skilled in
the art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this invention, but that the invention will include
all embodiments falling within the scope of the appended
claims.
* * * * *