The present disclosure relates generally to air conditioning systems; and more specifically, to condensers adapted to be used for air conditioning systems employing internal heat exchangers.
BACKGROUND
Recently, the use of air conditioning systems is growing rapidly due to increasing global temperatures and they are being used in various places including homes, offices, automobiles and so forth. Considering the rapid growth in the use of air conditioning systems, there is an urgent need to improve design, performance and efficiency thereof. For example, the air conditioning systems that are being used these days are required to provide improved efficiency per unit of power consumed, and they are also required to have a smaller form factor as compared to conventional air conditioning systems. Therefore, a lot of modern air conditioning systems employ components such as internal heat exchangers, thermal expansion valves and forth to improve their performance while having a small form factor.
It will be appreciated that the improvement in the performance of the air conditioning systems by employing the aforementioned components may be dependent on various factors apart from the components themselves. For example, the internal heat exchanger may be operatively coupled to other parts of the air conditioning system, such as a condenser, an evaporator and so forth. In such an example, an operation of the internal heat exchanger may depend on operation of the condenser and/or the evaporator. The refrigerant may undergo a change in state, temperature and/or pressure within the condenser and subsequently, the refrigerant may flow into the internal heat exchanger for cooling thereof. However, the operation of the condenser may be inadequate to sufficiently change the state, temperature and/or pressure of the refrigerant.
The inadequate operation of the condenser may lead to various problems. For example, the refrigerant in a liquid state flowing from the condenser may comprise a substantial concentration of the refrigerant in a vapour state. Such

a concentration of the vapour refrigerant in the liquid refrigerant may lead to improper functioning of the internal heat exchanger, leading to suboptimal performance of the air conditioning system and discomfort to users. In another example, an insufficient change in temperature of the refrigerant may restrict the thermal expansion valve from adapting to varying load conditions associated with the air conditioning system, thereby, causing suboptimal performance, decrease in efficiency and reduced reliability of the air conditioning system.
Therefore, in light of the foregoing discussion, there exist various problems associated with condensers of conventional air conditioning systems employing components such as the internal heat exchanger.
SUMMARY
The present disclosure seeks to provide an improved condenser adapted to be used for an air conditioning system employing an internal heat exchanger.
According to a first aspect, an embodiment of the present disclosure provides a condenser adapted to be used for an air conditioning system employing an internal heat exchanger, the condenser comprising:
a first header and a second header comprising a plurality of header separators, wherein the first header and the second header are in a fluidic communication with each other through a plurality of tubes and the plurality of tubes are separated from each other through a plurality of heat exchanging means;
a plurality of refrigerant flow sections with a refrigerant flow path of the condenser, wherein the plurality of refrigerant flow sections are created due to the plurality of header separators respectively and each refrigerant flow section of the plurality of refrigerant flow sections comprises at least a part of the plurality of tubes respectively;
a subcool region comprising a subcool area within at least one refrigerant flow section of the plurality of refrigerant flow sections, wherein the subcool area is in a range of 3 to 10% of a frontal condenser area; and
a free flow area within the plurality of tubes of the subcool region of the at least one refrigerant flow section for the refrigerant flow within the plurality

of tubes of the subcool area, wherein the free flow area is in a range of 16 to 34 square millimetres.
The present disclosure seeks to provide the condenser that enables subcooling of the liquid refrigerant flowing there through, thus, enabling the air conditioning system to substantially overcome problems associated with conventional air conditioning systems.
It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.
DESCRIPTION OF THE DRAWINGS
The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.
Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:
FIG. 1 is a schematic illustration of an air conditioning system employing an internal heat exchanger, in accordance with an embodiment of the present disclosure;
FIG. 2 is a schematic illustration of a front-view of the condenser of FIG. 1, in accordance with an embodiment of the present disclosure;
FIG. 3 is a schematic illustration of a cross section of a tube of the plurality of tubes (shown in FIG. 2), in accordance with an embodiment of the present disclosure;

FIG. 4 is a schematic illustration of a cross section of the subcool region of FIG. 2, in accordance with an embodiment of the present disclosure; and
FIG. 5 is a graph illustrating a comparison between coefficient of performance (COP) achieved by the condenser of the air conditioning system of the present disclosure, with respect to condensers of conventional air conditioning systems, in accordance with an embodiment of the present disclosure.
In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.
DESCRIPTION OF EMBODIMENTS
In overview, embodiments of the present disclosure are concerned with air conditioning systems employing internal heat exchangers.
Referring to FIG. 1, there is shown a schematic illustration of an air conditioning system 10 employing an internal heat exchanger 12, in accordance with an embodiment of the present disclosure. The air conditioning system 10 comprises a compressor 14, a condenser 16 adapted to be used for the air conditioning system 10 employing the internal heat exchanger 12, a thermal expansion valve 18 and an evaporator 20. The air conditioning system 10 can be implemented in automobiles including, but not limited to, a bus, a truck, a car, an ambulance, a school bus, a minibus and other kinds of commercial or non-commercial (such as personal) automobiles. The air conditioning system 10 employs a refrigerant that is allowed to flow through the components 12-20 mentioned herein above, to extract heat from within an enclosure (such as the automobile) and exhaust the heat to an ambient atmosphere.
The refrigerant flows into the compressor 14 in a vapour form and the compressor 14 is operable to increase the pressure of the refrigerant. As

shown, the compressor 14 is operatively coupled to the condenser 16. The vapour refrigerant having the high pressure and high temperature flows from the compressor 14 into the condenser 16. The condenser 16 is operable to change a state of the refrigerant from the vapour state to a liquid state and also, remove heat from the refrigerant in the liquid state. The internal heat exchanger 12 is operatively coupled to the condenser 16 and the evaporator 20. In an embodiment, the internal heat exchanger 12 is implemented as a suction line internal heat exchanger. In another embodiment, the internal heat exchanger 12 is implemented as a coaxial tube internal heat exchanger. The internal heat exchanger 12 is operable to further remove heat from the low temperature liquid refrigerant flowing from the condenser 16 into the internal heat exchanger 12.
The thermal expansion valve 18 is operable to adjust an amount of the low temperature liquid refrigerant flowing into the evaporator 20, to control superheating of the refrigerant flowing out of the evaporator 20. The evaporator 20 is operatively coupled to the internal heat exchanger 12 via the thermal expansion valve 18. The evaporator 20 is operable to change the state of the refrigerant from the liquid state to the vapour state bytransferring enclosure heat to the refrigerant. Thus, the components 12-20 establish a refrigeration cycle within the automotive air conditioning system 10, allowing the refrigerant to remove heat from within the enclosure (such as an automobile).
Referring to FIG. 2, there is shown a schematic illustration of a front-view of the condenser 16 of FIG. 1, in accordance with an embodiment of the present disclosure. The condenser 16 comprises a first header 22A and a second header 22B comprising a plurality of header separators 24, wherein the first header 22A and the second header 22B are in a fluidic communication with each other through a plurality of tubes 26. As shown, the first header 22A and the second header 22B are communicatively coupled at either end of the plurality of tubes 26. The first header 22A and the second header 22B act as common flow channels for flow of the refrigerant between each of the plurality of tubes 26, such that the refrigerant flows through the plurality of tubes 26 viathe first header 22A and the second header 22B. The first header

22Acomprises an inlet connector 28 and an outlet connector 30, wherein the inlet connector 28 couples the condenser 16 with the compressor 14 (shown in FIG. 1) and the outlet connector 30 couples the condenser 16 with the internal heat exchanger 12 (shown in FIG. 1). The inlet connector 28 allows flow of high temperature vapour refrigerant from the compressor 14 into the condenser 16. The outlet connector 30 allows flow of subcooled refrigerant (explained in detail herein later) from the condenser 16 into the internal heat exchanger 12.
Each of the plurality of tubes 26 can be implemented as flat tubes, such as tubes having a rectangular cross section with a pair of rounded sides (shown in FIG. 3). The plurality of tubes 26 are separated from each other through a plurality of heat exchanging means 32. As shown, the plurality of heat exchanging means 32 comprises corrugated louver fins coupled to each tube of the plurality of tubes 26. The corrugated louver fins enable each tube of the plurality of tubes 26 to dissipate heat therefrom by convection with air flowing over the condenser 16. Such a dissipation of heat enables the condensation and temperature reduction of the refrigerant flowing inside each tube of the plurality of tubes 26.
The condenser 16 comprises a plurality of refrigerant flow sections 34A-D with a refrigerant flow path of the condenser 16 (indicated by a dash-dot line), wherein the plurality of refrigerant flow sections 34A-Dare created due to the plurality of header separators 24 respectively and each refrigerant flow section of the plurality of refrigerant flow sections 34A-D comprises at least a part of the plurality of tubes 26 respectively. As shown, the refrigerant is operable to enter into the inlet connector 28 and subsequently, flow along the refrigerant flow section 34A. Furthermore, the refrigerant flow section 34A is associated with a specific number of tubes constituting the plurality of tubes 26, such as tubes arranged near a top of the condenser 16. Consequently, the refrigerant is operable to flow in the part of the plurality of tubes 26 corresponding to the refrigerant flow section 34A. Thereafter, the refrigerant is operable to flow into the second header 22B wherefrom the refrigerant flows into part of the plurality of tubes 26 corresponding to the refrigerant flow section 34B

As shown, the condenser 16 further comprises a receiver drier assembly 36 communicatively coupled to the second header 22B via an inlet connector 38 and an outlet connector 40, wherein the receiver drier assembly 36 comprises at least a desiccant media 42 and a filter 44. The receiver drier assembly 36 comprises a housing 46. The housing 46 is operable to contain therein, at least the desiccant media 42, and the filter 44. The desiccant media 42 is operable to absorb moisture from the refrigerant flowing from the condenser 16 into the receiver drier assembly 36 via the inlet connector 38. Furthermore, the filter 44 is operable to remove impurities that may be present in the refrigerant flowing thereto, such that the refrigerant flowing out of the receiver drier assembly 36 via the outlet connector 40 is substantially free of impurities.
The condenser 16 comprises a subcool region 48 (shown as a shaded region in a lower section of the condenser 16) comprising a subcool area Ag within at
least one refrigerant flow section of the plurality of refrigerant flow sections 34A-D, wherein the subcool area Ag is in a range of 3 to 10% of a frontal
condenser area A^. As shown, the condenser 16 has a height H and a width
W. In such an instance, the frontal condenser area A^ can be mathematically
expressed as:
AC = W x H
Furthermore, the subcool region 48 has a height S and the width W. Mathematically, the frontal subcool area Ag can be expressed as:
AS = W x S
Therefore, a ratio of the frontal subcool area to the frontal condenser area Ag:Ac is given by:
As _ W x S _ S
A^ ~ W x H ~ H
Thus, the ratio of the subcool area to the frontal condenser area Ag:Ac is
dependent on the height of the subcool area S and the condenser H respectively i.e. the ratio of the subcool area to the frontal condenser area

Ag:Ac is a ratio of the height of the subcool area S and height of the condenser H.
Moreover, the ratio Ag:Ac can be expressed in a percentage form as:
X = -x 100 H
The frontal subcool area Ag is in the range of 3 to 10% of the frontal condenser area A^ or based on above equation, X is in a range of 3 to 10.
As shown, the subcool area Ag of condenser includes a portion of the frontal condenser area A^ which corresponds to a plurality of tubes which are downstream of the outlet connector 40 of the receiver drier assembly 36.
The subcool region 48 corresponds to the refrigerant flow section 34D and constitutes a section near a bottom of the condenser 16. Thus, the subcool area Ag corresponds to the part of the plurality of tubes 26associated with the
section near the bottom of the condenser 16 or the refrigerant flow section 34D. As shown, the subcool region 48 is in fluidic communication with the receiver drier assembly 36 via the outlet connector 40 such that the dried refrigerant that is substantially free of impurities from the receiver drier assembly 36 flows into the subcool region 48 of the condenser 16. In such an instance, as the refrigerant flows into the subcool region 48 after flowing out of the receiver drier assembly 36, the subcool area Ag corresponds to the
plurality of tubes which are downstream of the outlet connector 40 of the receiver drier assembly 36.
In operation, the high temperature refrigerant in the vapour state flows from the compressor 14 (shown in FIG. 1) into the condenser 16 through the inlet connector 28. Subsequently, the refrigerant flows through the condenser 16 wherein the state of the refrigerant undergoes a change from the vapour state to the liquid state and simultaneously, the temperature of the refrigerant is reduced. Thereafter, the low temperature liquid refrigerant flows via inlet connector 38 into the receiver drier assembly 36, wherein the refrigerant moisture and impurities are removed therefrom. Subsequently, the refrigerant flows via the outlet connector 40 into the subcool region 48 of the condenser

16 wherein the temperature of the liquid refrigerant is further reduced i.e. the liquid refrigerant is subcooled. The subcooling of the liquid refrigerant in the subcool region 48 enables a reduction in presence of vapours in the liquid refrigerant flowing to other components of the air conditioning system 10, such as the internal heat exchanger 12 and/or the thermal expansion valve 18 and consequently, enables proper functioning thereof. It will be appreciated that the proper functioning of the components enables the air conditioning system 10 to achieve higher efficiency as compared to conventional air conditioning systems. For example, the air conditioning system 10 can achieve higher coefficient of performance (or COP) as compared to conventional air conditioning systems (as shown in FIG. 5). Referring now to Figures 3 and 4, there is shown a schematic illustration of a cross section of a tube 50 of the plurality of tubes 26 (shown in FIG. 2), in accordance with an embodiment of the present disclosure. As shown, each cross section of tube 50 of the plurality of tubes 26 comprises a plurality of ports 52, and wherein adjacent ports of the plurality of ports 52 are separated by a partitioning wall 54. The refrigerant flows through cross section of the tube 50 along the plurality of ports 52. The partitioning walls 54 prevent fluidic communication of the refrigerant from one port to an adjacent port of the plurality of ports 52. The plurality of ports 52 of each cross section of tube 50 provides a free flow area Af for flow of the refrigerant through the
cross section of tube 50.
The free flow area Af of each cross section of tube 50 is dependent on a
number of ports per tube n, a port wall thickness t, a tube height h, a tube width w, a tube wall thickness T. As shown, the cross section of tube 50 is associated with the tube height h, the width w, tube wall thickness T and end radius r. Furthermore, the cross section of tube 50 comprises n number of ports 52, wherein each port has a port wall thickness t. In such an instance, the free flow area Af of the cross section of tube 50 can be mathematically
expressed as:
Af = (h - 2T)(w - 2r - (n - l)t) + n(r - T)2

The free flow area within the plurality of tubes 26 of the subcool area is dependent on a free flow area of each tube of the plurality of tubes 26. In such an instance, when the plurality of tubes 26 of the subcool area comprises N number of tubes, the total free flow area for the refrigerant within the subcool region is given by:
AT = [(h - 2T)(w - 2r - (n - l)t) + n(r - T)2]xN
Furthermore, the total free flow area Ay associated with the subcool area is in
the range of 16 to 34 square millimetres. For example, the free flow area Aj
can be 16 square millimetres, 20 square millimetres, 25.5 square millimetres, 29 square millimetres, 33.9 square millimetres, 34 square millimetres and so forth.
Referring to FIG. 5, there is shown a graph illustrating a comparison between coefficient of performance (COP) achieved by the condenser of the air conditioning system of the present disclosure, with respect to condensers of conventional air conditioning systems, in accordance with an embodiment of the present disclosure. As shown, the condenser of the air conditioning system of the present disclosure achieves a higher coefficient of performance (COP) as compared to condensers of conventional air conditioning systems.
The condenser of the present disclosure comprises the plurality of tubes separated from each other through the plurality of heat exchanging means. The heat exchanging means provide increased dissipation of heat from the plurality of tubes, enabling improved cooling of the refrigerant flowing through the condenser. Furthermore, the condenser comprises the subcool region, wherein the free flow area is provided for flow of the refrigerant within the plurality of tubes of the subcool region. The subcool region enables additional removal of heat from the liquid refrigerant flowing through the condenser, thereby enabling the liquid refrigerant to be subcooled. Such a subcooling of the liquid refrigerant enables an improved performance of the air conditioning system, such as, increased coefficient of performance. Furthermore, the subcooling of the liquid refrigerant enables reliable operation of the components such as the internal heat exchanger and/or the thermal expansion

valve. It will be appreciated that the increased coefficient of performance and the reliable operation of the components provides improved cooling by the air conditioning system, thus, providing a desirable experience for users thereof. Therefore, the condenser of the present disclosure substantially overcomes various problems associated with condensers of conventional air conditioning systems.
Modifications to embodiments of the invention described in the foregoing are possible without departing from the scope of the invention as defined by the accompanying claims. Expressions such as "including", "comprising", "incorporating", "consisting of", "have", "is" used to describe and claim the present invention are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural. Numerals included within parentheses in the accompanying claims are intended to assist understanding of the claims and should not be construed in any way to limit subject matter claimed by these claims.

WE CLAIM

1.A condenser adapted to be used for an air conditioning system
employing an internal heat exchanger, the condenser comprising:
a first header and a second header comprising a plurality of header separators, wherein the first header and the second header are in a fluidic communication with each other through a plurality of tubes and the plurality of tubes are separated from each other through a plurality of heat exchanging means;
a plurality of refrigerant flow sections with a refrigerant flow path of the condenser, wherein the plurality of refrigerant flow sections are created due to the plurality of header separators respectively and each refrigerant flow section of the plurality of refrigerant flow sections comprises at least a part of the plurality of tubes respectively;
a subcool region comprising a subcool area within at least one refrigerant flow section of the plurality of refrigerant flow sections, wherein the subcool area is in a range of 3 to 10% of a frontal condenser area; and
a free flow area within the plurality of tubes of the subcool region of the at least one refrigerant flow section for the refrigerant flow within the plurality of tubes of the subcool area, wherein the free flow area is in a range of 16 to 34 square millimetres.
2.The condenser as claimed in claim 1, wherein the free flow area within the plurality of tubes of the subcool area is dependent on a free flow area of each tube of the plurality of tubes.
3.The condenser as claimed in claim 2, wherein the free flow area of each tube is dependent on a number of ports per tube, a port wall thickness, a tube height, a tube width and a tube wall thickness.
4.The condenser as claimed in claim 1, wherein a ratio of the subcool area to the frontal condenser area is dependent on a height of the subcool area and the condenser respectively.

5.The condenser as claimed in claim 1, further comprising a receiver drier assembly communicatively coupled to the second header via an inlet connector and an outlet connector, wherein the receiver drier assembly comprises at least a desiccant media and a filter.
6.The condenser as claimed in claim 5, wherein the subcool area of condenser includes a portion of the frontal condenser area which corresponds to a plurality of tubes which are downstream of the outlet connector of the receiver drier assembly.
7.The condenser as claimed in claim 6, wherein each of the plurality of tubes comprises a plurality of ports, and wherein adjacent ports of the plurality of ports are separated by a partitioning wall.
8.The condenser as claimed in claim 1, wherein the plurality of heat
exchanging means comprises corrugated louver fins coupled to each tube of
the plurality of tubes.
9.The condenser as claimed in claim 1, wherein the first header comprises an
inlet connector and an outlet connector, wherein the inlet connector couples
the condenser with a compressor and the outlet connector couples the
condenser with the internal heat exchanger.
10.The condenser as claimed in claim 1, wherein the internal heat exchanger
employed within the air conditioning system is implemented as a suction line
internal heat exchanger.