AN IMPROVED AIR CONDITIONING SYSTEM
TECHNICAL FIELD
The present disclosure generally relates to the field of air conditioners. Particularly,
the present disclosure relates to the construction and mechanism of an improved air
conditioning system comprising a sub-cooling unit thereby enhancing the efficiency
of the air conditioning system.
BACKGROUND OF THE PRESENT DISCLOSURE
The information in this section merely provides background information related to the
present disclosure and may not constitute prior art(s).
Generally, multi compartment air conditioning systems are used for regulating the
temperature of closed systems such as buildings. As shown in figure 1, such air
conditioning systems comprise an evaporating unit (1) and a condenser unit (2)
through which refrigerants such as chlorofluorocarbons, are circulated to draw heat
from a region of higher temperature to provide cooling effect. The air conditioning
systems comprise a compressor (3) which normally serves to circulate the refrigerant
and has a low-pressure or suction inlet (5) which receives vapor refrigerant from an
evaporating heat exchanger (i.e. evaporator unit (1)) and a high-pressure outlet which
discharges compressed refrigerant into a high-pressure line (6). The compressed
refrigerant is commonly received by a condensing heat exchanger commonly known
as the condenser unit (2), in which heat from the compressed refrigerant is transferred
to another medium, most commonly air or water. The cooled and condensed
refrigerant is then conveyed along the high-pressure liquid line (7) to an expansion
unit (4) which discharges the refrigerant through a narrow orifice into the evaporating
heat exchanger/evaporator unit (1), causing expansion and evaporation of the
refrigerant and consequently providing a cooling effect. However, one major
drawback of such systems is that the temperature of the liquid refrigerant flowing
from the condensing heat exchanger (2) to the expansion unit (4) is high. This
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decreases the performance of the expansion unit (4) and subsequently the evaporator
unit (1), thereby decreasing the energy efficiency of the air conditioning system.
Therefore, there was a need to develop a technically advance air conditioning system.
More specifically, an air conditioning system that has better energy efficiency and
overcomes one or more limitations stated above.
SUMMARY
One or more drawbacks of conventional air conditioning systems as described in the
prior art are overcome and additional advantages are provided through the improved
air conditioning system as claimed in the present disclosure. Additional features and
advantages are realized through the technicalities of the present disclosure. Other
embodiments and aspects of the disclosure are described in detail herein and are
considered to be a part of the claimed disclosure.
In one non-limiting embodiment of the present disclosure, there is provided an
improved air conditioning system comprising an evaporator unit connected with a
condenser unit in a continuous circuit carrying a refrigerant. The improved air
conditioning system comprises a compressor unit for compressing the refrigerant from
low-pressure vapor in the evaporator unit to high-pressure vapor in the condenser
unit. An expansion unit device for converting the refrigerant from high-pressure liquid
phase in the condenser unit to low-pressure liquid in the evaporator unit. A plurality
of conduits for carrying the refrigerant. A sub cooling unit comprising a second tube
being disposed concentrically in a first tube such that the sub-cooling unit is
configured to cool the high-pressure liquid refrigerant from the condenser unit by
means of a heat exchange step with the low-pressure vapor refrigerant from the
evaporator unit.
In an embodiment of the present disclosure, each of the first and second tubes is
configured to carry the refrigerant in the continuous circuit.
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In an embodiment of the present disclosure, the first tube carries the low-pressure
vapor refrigerant from the evaporator unit to the compressor unit.
In an embodiment of the present disclosure, the second tube carries the high-pressure
liquid refrigerant from the condenser unit to the expansion unit.
In an embodiment of the present disclosure, the heat exchange in the sub cooling unit
between the first and second tubes is by counter current flow of the high-pressure
liquid refrigerant in the second tube with respect to the low-pressure vapor refrigerant
in the first tube.
The foregoing summary is illustrative only and is not intended to be in any way
limiting. In addition to the illustrative aspects, embodiments, and features described
above, further aspects, embodiments, and features will become apparent with
reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The novel features and characteristics of the disclosure are set forth in the appended
description. The disclosure itself, however, as well as a preferred mode of use, further
objectives and advantages thereof, will best be understood by reference to the
following detailed description of an illustrative embodiment when read in conjunction
with the accompanying figures. One or more embodiments are now described, by way
of example only, with reference to the accompanying figures wherein like reference
numerals represent like elements and in which:
Figure 1 illustrates a schematic view of a conventional air conditioning system.
Figure 2 depicts a perspective view of an improved air conditioning system in
accordance with the present disclosure.
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Figure 3 shows a perspective view of the sub-cooling unit of the improved air
conditioning system of Figure 2, according to an embodiment of the present
disclosure.
Figure 4 illustrates a pressure-enthalpy curve for the air conditioning system of
Figure 2, according to an embodiment of the present disclosure.
Figure 5 illustrates a perspective view of the sub-cooling view with the condenser
unit of the air conditioning system of Figure 2, according to an embodiment of the
present disclosure.
The figures depict embodiments of the disclosure for purposes of illustration only.
One skilled in the art will readily recognize from the following description that
alternative embodiments of the structures and methods illustrated herein may be
employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
While the embodiments in the disclosure are subject to various modifications and
alternative forms, specific embodiments thereof have been shown by way of example
in the figures and will be described below. It should be understood, however that it is
not intended to limit the disclosure to the particular forms disclosed, but on the
contrary, the disclosure is to cover all modifications, equivalents, and alternative
falling within the scope of the disclosure.
It is to be noted that a person skilled in the art would be motivated from the present
disclosure and modify various constructions of an improved air conditioning system.
However, such modifications should be construed within the scope and spirit of the
disclosure. Accordingly, the drawings show only those specific details that are
pertinent to understand the embodiments of the present disclosure so as not to obscure
the disclosure with details that will be readily apparent to those of ordinary skill in the
art having benefit of the description herein.
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The terms “comprises”, “comprising”, or any other variations thereof used in the
disclosure, are intended to cover a non-exclusive inclusion, such that a device, system,
assembly that comprises a list of components does not include only those components
but may include other components not expressly listed or inherent to such system, or
assembly, or device. In other words, one or more elements in a system or device
proceeded by “comprises… a” does not, without more constraints, preclude the
existence of other elements or additional elements in the system or device.
Accordingly, it is an aim of the present disclosure to provide an improved air
conditioning system that provides better cooling with relatively minimal consumption
of energy thereby improving the overall energy efficiency of the air conditioning
system.
Accordingly, the present disclosure provides an improved air conditioning system
comprising an evaporator unit connected with a condenser unit in a continuous circuit
carrying a refrigerant. The improved air conditioning system comprises a compressor
unit for compressing the refrigerant from low-pressure vapor in the evaporator unit to
high-pressure vapor in the condenser unit. An expansion unit device for converting
the refrigerant from high-pressure liquid phase in the condenser unit to low-pressure
liquid in the evaporator unit. A plurality of conduits for carrying the refrigerant. A sub
cooling unit comprising a second tube being disposed concentrically in a first tube
such that the sub-cooling unit is configured to cool the high-pressure liquid refrigerant
from the condenser by means of a heat exchange step with the low-pressure vapor
refrigerant from the evaporator unit. Each of the first and second tubes is configured
to carry the refrigerant in the continuous circuit such that the first tube carries the lowpressure
vapor refrigerant from the evaporator unit to the compressor unit and the
second tube carries the high-pressure liquid refrigerant from the condenser to the
expansion unit. The heat exchange in the sub cooling unit between the first and
second tubes is by counter current flow of the high-pressure liquid refrigerant in the
second tube with respect to the low-pressure vapor refrigerant in the first tube.
The following paragraphs describe the present disclosure with reference to Figures 2
to 4. In the figures the same element or elements which have same functions are
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indicated by the same reference signs. For the purpose of simplicity neither the
vehicle nor the passenger compartment is illustrated in the drawings.
Generally, air conditioning systems comprise, but are not limited to, a layout having
an indoor unit and an outdoor unit. The indoor unit is configured to provide cooling
effect to a desired area/closed space. For this purpose, the indoor unit comprises an
evaporator which facilitates absorption of heat by a liquid refrigerant under lowpressure.
The outdoor unit is placed in an open space such as rooftops. The indoor and
outdoor units are connected by means of one or more conduits, tubes, pipes or the
like, for carrying a refrigerant between the indoor and outdoor units in a continuous
cycle. The outdoor unit comprises a condenser which is configured to facilitate heat
exchange between the vapor refrigerant under high-pressure and the surroundings so
as to reduce the temperature of the refrigerant, leading to the condensation of the
refrigerant in the air conditioning cycle.
Accordingly, figures 2 to 5 illustrate an improved air conditioning system (100). As
shown in figure 2, the said air conditioning system comprises an evaporator unit (101)
and a condenser unit (106) being connected in a continuous circuit, defining the air
conditioning cycle. The evaporator unit (101) is a heat exchange device whereby heat
from a closed space is absorbed to provide cooling effect. The heat absorption by a
refrigerant under low-pressure results in phase change of the refrigerant from liquid
phase to vapor phase. The evaporator unit (101) comprises a low-pressure outlet
(101a). The low-pressure outlet (101a) is configured with a first tube (102) of the sub
cooling unit (103). The first tube (102) is adapted to carry the low-pressure vapor
refrigerant from the evaporator unit (101) to a compressor unit (104) via a sub cooling
unit (103). The compressor unit (104) is configured to compress the low-pressure
vapor from the evaporator unit (101) to high-pressure vapor refrigerant, thereby
further heating the vapor refrigerant. The compressor unit (104) is connected with the
condenser unit by a high-pressure vapor conduit (105). Thus, the compressed
refrigerant is discharged from the compressor unit (104) to the condenser unit (106)
by the high-pressure vapor line (105). As shown in figure 2, the condenser unit (106)
is a heat exchanger device which facilitates heat exchange between the high-pressure
vapor refrigerant and the surrounding air. Accordingly, the condenser unit (106)
comprises condenser coils through which the high-pressure vapor refrigerant flows for
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the purpose of heat exchange, thus resulting in change of phase of the refrigerant
under high-pressure from vapor phase to liquid phase. The liquid refrigerant is then
conveyed by means of a second tube (107) to via the sub cooling unit (103) to an
expansion unit (108). The sub cooling unit (103) is configured to cool the highpressure
liquid refrigerant from the condenser unit (106) by means of a heat exchange
step with the low-pressure vapor refrigerant in the first tube (102) from the evaporator
unit (101). This results in temperature drop of the high-pressure liquid refrigerant in
the second tube (107) by 4~6°C. The liquid refrigerant in the second tube (107) is
carried to the expansion unit (108) where the refrigerant is converted from high
pressure liquid phase to low pressure liquid phase, thereby further cooling the liquid
refrigerant. The low-pressure liquid refrigerant is conveyed to the evaporator unit
(101) by means of a low-pressure liquid conduit (109).
As shown in figure 3, the sub cooling unit (103) comprises an arrangement whereby
the second tube (107) is disposed concentrically in the first tube (102). In an
embodiment, the first and second tubes are arranged such that the direction of flow of
the high-pressure liquid refrigerant in the second tube (107) is opposite, i.e. counter
current, with respect to the direction of flow of the low-pressure vapor refrigerant in
the first tube (102). Thus, the heat exchange between the comparatively cooler vapor
refrigerant in the first tube (102) and the hotter liquid refrigerant in the second tube
(107) is by counter current flow of the of the high pressure liquid refrigerant in the
second tube with respect to the low pressure vapor refrigerant in the first tube.
The performance characteristics of an exemplary embodiment of the present
disclosure were compared with a conventional air conditioning system devoid of the
sub cooling unit. The comparative data of the improved air conditioning system (With
Sub Cooling Unit) and the conventional air conditioning system (Without the Sub
Cooling Unit) is as follows:
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Table 1
Table 2
De rating improvement by 5% under the De rating condition- 27/19, 48/29 @ 196 Volts
The test results show an improvement of 2 ~ 2.5% in energy efficiency and an
increased sub-cooling by 3~4 ̊C, of the improved air conditioning system with respect
to the conventional air conditioning systems.
List of reference numerals:
100 Improved Air Conditioning System
101 Evaporator Unit
W/O Sub
Cooling Unit
With Sub Cooling
Unit
With Sub Cooling
Unit
W/O Sub Cooling
Unit
10
101a Low Pressure Outlet of Evaporator Unit
102 First Tube
103 Sub Cooling Unit
104 Compressor Unit
105 High Pressure Vapor Conduit
106 Condenser Unit
107 Second Tube
108 Expansion Unit
109 Low Pressure Liquid Conduit
Equivalents:
With respect to the use of substantially any plural and/or singular terms herein, those
having skill in the art can translate from the plural to the singular and/or from the
singular to the plural as is appropriate to the context and/or application. The various
singular/plural permutations may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, and
especially in the appended claims (e.g., bodies of the appended claims) are generally
intended as “open” terms (e.g., the term “having” should be interpreted as “having at
least,” etc.). It will be further understood by those within the art that if a specific
number of an introduced claim recitation is intended, such an intent will be explicitly
recited in the claim, and in the absence of such recitation no such intent is present. For
example, as an aid to understanding, the following appended claims may contain
usage of the introductory phrases “at least one” and “one or more” to introduce claim
recitations. However, the use of such phrases should not be construed to imply that
the introduction of a claim recitation by the indefinite articles “a” or “an” limits any
particular claim containing such introduced claim recitation to inventions containing
only one such recitation, even when the same claim includes the introductory phrases
“one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a”
and/or “an” should typically be interpreted to mean “at least one” or “one or more”);
the same holds true for the use of definite articles used to introduce claim recitations.
In addition, even if a specific number of an introduced claim recitation is explicitly
recited, those skilled in the art will recognize that such recitation should typically be
interpreted to mean at least the recited number (e.g., the bare recitation of “two
recitations,” without other modifiers, typically means at least two recitations, or two
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or more recitations). It will be further understood by those within the art that virtually
any disjunctive word and/or phrase presenting two or more alternative terms, whether
in the description, claims, or drawings, should be understood to contemplate the
possibilities of including one of the terms, either of the terms, or both terms. For
example, the phrase “A or B” will be understood to include the possibilities of “A” or
“B” or “A and B.”
While various aspects and embodiments have been disclosed herein, other aspects and
embodiments will be apparent to those skilled in the art. The various aspects and
embodiments disclosed herein are for purposes of illustration and are not intended to
be limiting, with the true scope and spirit being indicated by the following claims.

We claim:
1. An improved air conditioning system (100) comprising:
an evaporator unit (101) connected with a condenser unit (106)
in a continuous circuit carrying a refrigerant;
a compressor unit (104) for compressing the refrigerant from
low pressure vapour in the evaporator unit to high pressure vapour in
the condenser unit;
an expansion unit (108) device for converting the refrigerant
from high pressure liquid phase in the condenser unit to low pressure
liquid in the evaporator unit;
a plurality of conduits for carrying the refrigerant; and
a sub cooling unit (103) comprising a second tube (107) being
disposed concentrically in a first tube (102); the sub-cooling unit (103)
being configured to cool the high-pressure liquid refrigerant from the
condenser unit (106) by means of a heat exchange step with the low
pressure vapor refrigerant from the evaporator unit (101).
2. The improved air conditioning system as claimed in claim 1, wherein each of
the first and second tubes (102, 107) is configured to carry the refrigerant in
the continuous circuit.
3. The improved air conditioning system as claimed in claim 1, wherein the first
tube (102) carries the low pressure vapor refrigerant from the evaporator unit
(101) to the compressor unit (104).
4. The improved air conditioning system as claimed in claim 1, wherein the
second tube (107) carries the high pressure liquid refrigerant from the
condenser unit (106) to the expansion unit (108).
5. The improved air conditioning system as claimed in claim 1, wherein heat
exchange in the sub cooling unit (103) between the first and second tubes is by
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counter current flow of the high pressure liquid refrigerant in the second tube
(107) with respect to the low pressure vapor refrigerant in the first tube (102).