The present subject matter relates to air conditioning units.
BACKGROUND OF THE INVENTION:
Geographical regions, such as tropical regions are characterized by high temperature and
humid weather conditions. Owing to such uncomfortable weather conditions, day-to-day living
becomes difficult in such regions. Thus, air conditioning units have become an indispensable
commodity in such geographical regions.
An air conditioning unit operates to remove heat and moisture from a room or a closed
space, such as a vehicle. Operation of the air conditioning unit involves condensing a refrigerant
by a condenser of the air conditioning unit using ambient air. Temperature of ambient air in such
geographical regions is usually in the range of about 35-48 degrees. Owing to such high
temperature of the ambient air, efficiency of the condenser and thus, the air conditioning unit is
reduced. Thus, deployment of air conditioning units having large capacity condenser becomes
necessary to maintain cool temperature in small spaces. As a result, power consumption and in
turn monetary expenses increase proportionally.
Summary of the invention:
This summary is provided to introduce a selection of concepts in a simplified format that
are further described in the detailed description of the invention. This summary is not intended to
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identify key or essential inventive concepts of the claimed subject matter, nor is it intended for
determining the scope of the claimed subject matter.
According to an embodiment, an air conditioning unit is disclosed. The unit comprises an
evaporator and a compressor. The unit further comprises a first conduit coupling the evaporator
to the compressor and configured to carry a refrigerant from the evaporator to the compressor.
The unit further comprises a first heat exchanger configured to carry a first liquid, the first heat
exchanger disposed along a portion of the first conduit, such that a first heat exchange is affected
between the refrigerant and the first liquid. The unit further comprises a first unit coupled to the
first heat exchanger and configured to receive the first liquid from the first heat exchanger post
the heat exchange between the first liquid and the refrigerant, wherein the first unit is disposed
with respect to the evaporator such that in a first air flow cycle of air through the AC unit, the air
passes over the first unit and the evaporator in said order.
Super-efficient air cooling solution has been developed by deploying evaporative cooling
combined with pre-cooling heat exchanger and then cooling by de-humidification (using
refrigeration system) deploying evaporatively cooled condenser. This is the most effective
management of heat balancing to achieve super energy efficient cooling solution. The
technology is described through psychrometric chart as shown. The pre-cooling heat exchanger
is supplied with cooling media which is cooled down to refrigerant temperature returning back to
compressor while maintaining the super heat refrigerant. By this the cooling media temperature
is brought down as close to the refrigerant returning temperature which is lower than the coolant
temperature achieved solely by evaporative cooling. This cooling media brings down the room
air temperature closer to the cooling media temperature which further cooled by
dehumidification (evaporator heat exchanger). The combination of evaporatively cooled
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condenser, cooling media precooled by returning refrigerant and primary cooling of indoor air by
cooling media in the primary heat exchanger allows effective heat balance and thus bringing
highest efficiency of operation. The efficiency of the air conditioning system is estimated to be in
the order of 7 to 8 COP which is double the efficiency of conventional air conditioning systems.
The cooling effect of 60-70% is provided by the combination of coaxial heat exchanger
deployed to pre-cool the cooling media while maintaining the super heat of refrigerant and
primary cooling of indoor air by cooling media and then evaporator heat exchanger. The
evaporatively cooled air cooling the condenser and cooling supplemented by the pre-cooling +
primary cooling of indoor air enhances the energy efficiency from conventional air conditioning
system.
Brief Description of the drawings:
To further clarify advantages and aspects of the invention, a more particular description
of the invention will be rendered by reference to specific embodiments thereof, which are
illustrated in the appended drawings, wherein:
Fig. 1 illustrates a schematic diagram of an air conditioning unit, in accordance with an
embodiment of the present invention;
Fig. 2 illustrates a schematic diagram of a first heat exchanger implemented in the air
conditioning unit, in accordance with an embodiment of the present invention;
Fig. 3 illustrates a schematic diagram of a second heat exchanger implemented in the air
conditioning unit, in accordance with an embodiment of the present invention; and
Fig. 4 illustrates a line diagram of an air conditioning unit, in accordance with an
embodiment of the present invention.
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It may be noted that to the extent possible, like reference numerals have been used to
represent like elements in the drawings. Further, those of ordinary skill in the art will appreciate
that elements in the drawings are illustrated for simplicity and may not have been necessarily
drawn to scale. For example, the dimensions of some of the elements in the drawings may be
exaggerated relative to other elements to help to improve understanding of aspects of the
invention. Furthermore, the one or more elements may have been represented in the drawings by
conventional symbols, and the drawings may show only those specific details that are pertinent
to understanding the embodiments of the invention so as not to obscure the drawings with details
that will be readily apparent to those of ordinary skill in the art having benefit of the description
herein.
Detailed Description of the invention:
For the purpose of promoting an understanding of the principles of the invention,
reference will now be made to the embodiment illustrated in the drawings and specific language
will be used to describe the same. It will nevertheless be understood that no limitation of the
scope of the invention is thereby intended, such alterations and further modifications in the
illustrated system, and such further applications of the principles of the invention as illustrated
therein being contemplated as would normally occur to one skilled in the art to which the
invention relates. It will be understood by those skilled in the art that the foregoing general
description and the following detailed description are explanatory of the invention and are not
intended to be restrictive thereof.
Reference throughout this specification to “an aspect”, “another aspect” or similar
language means that a particular feature, structure, or characteristic described in connection with
the embodiment is included in at least one embodiment of the present invention. Thus,
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appearances of the phrase “in an embodiment”, “in another embodiment” and similar language
throughout this specification may, but do not necessarily, all refer to the same embodiment.
The terms "comprises", "comprising", or any other variations thereof, are intended to
cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does
not include only those steps but may include other steps not expressly listed or inherent to such
process or method. Similarly, one or more devices or sub-systems or elements or structures or
components proceeded by "comprises... a" does not, without more constraints, preclude the
existence of other devices or other sub-systems or other elements or other structures or other
components or additional devices or additional sub-systems or additional elements or additional
structures or additional components.
Unless otherwise defined, all technical and scientific terms used herein have the same
meaning as commonly understood by one of ordinary skilled in the art to which this invention
belongs. The system, methods, and examples provided herein are illustrative only and not
intended to be limiting. Embodiments of the present invention will be described below in detail
with reference to the accompanying drawings.
Fig. 1 illustrates an air conditioning unit 100, hereinafter “unit 100”, according to an
embodiment of the present subject matter. In an example, amongst other things, the unit 100 may
include an evaporator 102, a condenser 104, and a compressor 106. The unit 100 further includes
a first conduit 108 that couples the evaporator 102 to the compressor 106. In an example, the first
conduit 108 may be configured to carry a refrigerant from the evaporator 102 to the compressor
106.
According to an example embodiment of the present subject matter, the unit 100 includes
a first heat exchanger 112 that is configured to carry a first liquid 114. A non-limiting example of
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first liquid 114 is water. In said embodiment, the first heat exchanger 112 may be disposed along
a portion of the first conduit 108, such that a first heat exchange is affected between the
refrigerant 110 and the first liquid 114. In an example, in the first heat exchange between the
refrigerant 110 and the first liquid 114, a temperature of the first liquid 114 may decreases from a
first temperature to a second temperature. Herein, the first temperature may be in the range of 28
to 32 degree Celsius and the second temperature may be in the range of 10 to 14 degree Celsius.
Referring to Fig. 1 and Fig. 2, in an example embodiment, the first heat exchanger 112
may be in the form of a third conduit only that is concentric with respect to the portion of the
first conduit 108. In said embodiment, the first liquid 114 is carried in a region defined by an
inner wall 200 of the third conduit and an external wall 202 of the portion of the first conduit
108. Accordingly, the first heat exchange 112 is affected between the refrigerant 110 and the first
liquid 114. Furthermore, in said embodiment, an opening at each of diagonally opposite ends of
the third conduit may be provided, such that upon assembly, the portion of the first conduit 108
becomes concentric with the third conduit. In an example, the size of the opening is such that a
diameter of the first conduit 108 fits into the opening. Accordingly, during assembly, the first
conduit is passed through the openings. Thus, a portion of the first conduit 108 becomes
concentric with the third conduit. In an example embodiment, the unit 100 further includes a first
storage tank 126 configured to store the first liquid 114. Furthermore, the unit 100 also includes a
pump (not shown in figure) that is configured to supply the first liquid 114 from the first storage
tank 126 to the first heat exchanger 112.
In an example embodiment, the unit 100 further includes a first unit 116. In an example,
the first unit 116 may be disposed with respect to the evaporator 102 such that in a first air flow
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cycle of air through the AC unit, the air passes over the first unit 116 and the evaporator 102, in
said order. Furthermore, in an example, the first unit 116 may include a set of fins and tubes.
In an example, the first unit 116 may be coupled to the first heat exchanger 112 and
configured to receive the first liquid 114 from the first heat exchanger 108 post the heat
exchange between the first liquid 114 and the refrigerant 110. As is mentioned above, post the
first heat exchange operation, the first liquid 114 is at the second temperature and the disposition
of the first unit 116 is such that the passing of the air over the first unit causes reduction in the
temperature of the air. Thus, the cooling load on the evaporator 102 is reduced as a cooled down
air then passes over the evaporator 102. Thus, energy efficiency of this cycle of air flow is
increased.
In a further example, the unit 100 may include an expansion valve 118 and a second
conduit 120 that couples the condenser 104 to the expansion valve 118. In said example, the
second conduit 120 is configured to carry the refrigerant 118 from the condenser 104 to the
expansion valve 118.
Referring to Fig. 1 and Fig. 3, in an example embodiment, the unit 100 further includes a
second unit 122. In an example, the second unit 122 includes a cooling pad 300. In an example,
the cooling pad 300 may be disposed adjacent to the condenser 104, so as to at least partially
cover a surface of the condenser 104 with the cooling pad 300. In an example, the second unit
122 may be coupled to the first unit 116 to receive the first liquid from the first unit 116. In an
example, the first liquid 114 flows through the cooling pad 300 of the second unit 122. As an
example, the first liquid 114 may be received at a water distribution pipe 302 that may sprinkle
the water over the cooling pad 300.
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In an example, the second unit 122 may be disposed in a region between a surface of the
condenser 104 and a condenser-side fan (not shown in the figure) of the unit 100. Accordingly,
the first liquid 114, that trickles down the cooling pad 300, lowers the temperature of the air
drawn in by the fan.
In an example embodiment, the unit 100 includes a second heat exchanger 124 that may
be configured to receive the first liquid 114 from the second unit 122. More particularly, in an
example embodiment, the second heat exchanger 124 may include a second storage tank 304 that
may be disposed relative to the cooling pad 300, such that the second storage tank 304 is
configured to receive the first liquid 114 from the second unit 122.
In a further example embodiment, the second heat exchanger 124 may include a fourth
conduit 128 that is configured to connect the second storage tank 304 with the first storage tank
126 for carrying the first liquid 114 back to the first storage tank 126.
In an example embodiment, the second heat exchanger 124 may be disposed along a
portion of the second conduit 120, such that the portion is at least partially submerged in the first
liquid 114 in the second heat exchanger 124. Accordingly, a second heat exchange is affected
between the refrigerant 110 and the first liquid 114. In an example, in the second heat exchange
between the refrigerant 110 and the first liquid 114, a temperature of the refrigerant 110
decreases from a first temperature to a second temperature. Herein, in an example, the first
temperature may be in a range of 32 to 36 degree Celsius and the second temperature is in the
range of about 26 to 28 degree Celsius.
Fig. 4 illustrates a line diagram of an example air conditioner 400, such as the unit 100,
according to an example embodiment of the present subject matter. The following legend is used
in the line diagram depicted in the diagram.
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Legend Description
CDS FIN TUBE HEAT EXCHANGER + EVAPORATIVE PAD
SC-HX SUB COOLER
EV ELECTRONIC EXPANSION VALVE
EVP FIN TUBE HEX REF SIDE+FIN TUBE HEX WATER SIDE
TS TEMPERATURE SENSOR
PS PRESSURE SENSOR
CO-AX-HX CO AXIAL HEAT EXCHANGER – SUPER HEATER
REF DC COMP DC - COMPRESSOR
DC FAN DC FANS
PUMP DC PUMP
Furthermore, the refrigeration side cycle involves the following processes:
REFRIGERATION SIDE CYCLE
PROCESS
DETAILS
DESCRIPTION
1-2 LIQUID REF EVAPORATES AT CONSTANT PRESSURE
2-3 CONSTANT PRESSURE SUPER HEATING
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3-4 ISENTROPIC COMPRESSION
4-6 CONSTANT PRESSURE CONDENSATION
6-7 CONSTANT PRESSURE SUB COOLING
7-1 ISENTROPIC EXPANSION
Furthermore, the water side cycle involves the following stages:
WATER SIDE CYCLE
A MAKE-UP WATER LINE
G CONDENSATE WATER FROM EVAPORATOR INTO TANK
K DRAIN WATER LINE
B-C WATER TEMPERATURE DROPS DUE TO SUPER HEATING OF
REFRIGERANT
C-D WATER TEMPERATURE INCREASES IN PRE COOLER HEAT
EXCHANGER
D-E WATER TEMPERATURE DROPS IN EVAPORATIVE PADS
E-F WATER TEMPERATURE INCREASES IN SUB COOLING HEAT
EXCHANGER
H WATER DRAIN LINE
J WATER TANK OVERFLOW LINE
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In an example, the operation of the air conditioner 400 is performed as follows. In said
example, the primary cooling media may be similar to the first liquid 114, i.e., may be water.
Primary cooling media circuit:
A – Supply Water from home tap
B to C – The water from tank flows through a co-axial heat exchanger. The Water at
initial temperature of 30 deg C is cooled by the refrigerant gas returning to compressor from
indoor heat exchanger which is at a temperature of 12 deg C. By this the primary cooling media
is brought down from 30 deg C to 20 – 25 deg C.
The refrigerant flowing 2 – 3 gains heat from water flowing B- C provides super heat
which reduces the load on compressor. Hence reducing the power consumption by compressor.
The room air to be conditioned is cooled from room temperature of 27deg C by the
primary cooling media flowing through heat primary cooling heat exchanger. The air is cooled
from 27 deg C to 26 – 22 deg C based on the entering room air temperature. This reduces the
load on indoor side heat exchanger to cool air thus reducing air 27 deg C air all cooled by
refrigerant, which reduces load on compressor.
The room air at 26 -22 deg C is cooled to 10 – 12 deg C by the refrigerant flowing in the
secondary heat exchanger indoor side. The refrigerant flowing 1 – 2 which is at 7 – 8 deg C.
The water is then flows on the evaporative cooling media D to E in the fine water droplet
form. The water thus flowing on the evporative cooling deck cools the outdoor hot air from 35 –
46 deg C to closer to 30 – 40 deg C based on the hot air temperature flowing on the evaporative
deck. This cooler air is then flows on the heat exchanger carrying hot refrigerant flow of 4 – 6
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which is at a temperature of 75 – 90 deg C. The hot refrigerant gas is brought down to liquid at
32 – 36 deg C based on the out door air entering temperature. The hot refrigerant liquid at 32 –
36 deg C is then flows E to F bringing down liquid refrigerant temperature from 32 – 36 deg C to
26 – 28 deg C. This sub cooling helps enhancing the cooling capacity. The evaporative cooled air
which flows over CDS heat exchanger reduces the load on compressor thus delivering higher
capacity at less power consumption. The condensate from latent heat removed from indoor air is
sent back to water sump. (G).
While specific language has been used to describe the present subject matter, any
limitations arising on account thereto, are not intended. As would be apparent to a person in the
art, various working modifications may be made to the method in order to implement the
inventive concept as taught herein. The drawings and the foregoing description give examples of
embodiments. Those skilled in the art will appreciate that one or more of the described elements
may well be combined into a single functional element. Alternatively, certain elements may be
split into multiple functional elements. Elements from one embodiment may be added to another
embodiment.

We Claim:
1. An Air Conditioning Unit, comprising:
an evaporator and a compressor;
a first conduit coupling the evaporator to the compressor and configured to carry a
refrigerant from the evaporator to the compressor;
a first heat exchanger configured to carry a first liquid, the first heat exchanger
disposed along a portion of the first conduit, such that a first heat exchange is affected
between the refrigerant and the first liquid; and
a first unit coupled to the first heat exchanger and configured to receive the first
liquid from the first heat exchanger post the heat exchange between the first liquid and
the refrigerant, wherein the first unit is disposed with respect to the evaporator such that
in a first air flow cycle of air through the AC unit, the air passes over the first unit and the
evaporator in said order.
2. The AC unit as claimed in claim 1, wherein the first heat exchanger is a third conduit
concentric with respect to the portion of the first conduit, wherein the first liquid is
carried in a region defined by an inner wall of the third conduit and an external wall of
the portion of the first conduit.
3. The AC unit as claimed in claim 1, wherein the first unit comprises a set of fins and a set
of tubes.
4. The AC unit as claimed in claim 1, wherein in the first heat exchange between the
refrigerant and the first liquid, a temperature of the first liquid decreases from a first
temperature to a second temperature.
5. The AC unit as claimed in claim 1, further comprising:
a condenser and an expansion valve;
a second conduit coupling the condenser to the expansion valve and configured to
carry the refrigerant from the condenser to the expansion valve;
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a second unit comprising a cooling pad and disposed adjacent to the condenser so
as to at least partially cover a surface of the condenser with the cooling pad, wherein the
second unit is coupled to the first unit to receive the first liquid from the first unit, and
wherein the first liquid flows through the cooling pad of the second unit; and
a second heat exchanger configured to receive the first liquid from the second unit,
the second heat exchanger disposed along a portion of the second conduit, such that the
portion is at least partially submerged in the first liquid in the second heat exchanger,
such that a second heat exchange is affected between the refrigerant and the first liquid.
6. The AC unit as claimed in claim 1, wherein in the second heat exchange between the
refrigerant and the first liquid, a temperature of the refrigerant decreases from a first
temperature to a second temperature.
7. The AC unit as claimed in claim 1, further comprising:
a first storage tank configured to store the first liquid; and
a pump configured to supply the first liquid from the first storage tank to the first
heat exchanger.
8. The AC unit as claimed in claim 7, wherein the second heat exchanger comprises:
a second storage tank disposed relative to the cooling pad such that the second
storage tank is configured to receive the first liquid from the second unit; and
a fourth conduit connecting the second storage tank with the first storage tank for
carrying the first liquid back to the first storage tank.
9. The AC unit as claimed in claim 5, wherein the second unit is disposed in a region
between the surface of the condenser and a condenser-side fan of the AC.