AU2014202998A1

AU2014202998A1 - A heat transfer arrangement for improved energy efficiency of an air conditioning system

Info

Publication number: AU2014202998A1
Application number: AU2014202998A
Authority: AU
Inventors: Eric Hu; Xuyang HUANG; Gerhard Kimenkowski
Original assignee: JUMBO VISION INTERNAT Pty Ltd
Current assignee: JUMBO VISION INTERNATIONAL Pty Ltd
Priority date: 2013-06-03
Filing date: 2014-06-03
Publication date: 2014-12-18
Anticipated expiration: 2034-06-03
Also published as: AU2014202998B2

Abstract

A heat transfer arrangement for improved energy efficiency of an air conditioning system having an underground and/or insulated fluid tank. A heat conducting element having a first portion submersible with a fluid of the tank and a second portion of the heat conducting element exposable to outside air. Cooling coils of a condenser of an air conditioning system submersed in said fluid of the tank such that when an air conditioning compressor of the air conditioning system compresses a refrigerant this provides for a heated refrigerant, wherein the heated refrigerant is then passable into the cooling coils of the condenser wherein the heated refrigerant heats the fluid in the fluid tank, wherein the heated fluid subsequently transfers heat from the fluid to the first portion of the heat conducting element and whereby heat from the first portion of the heat conducting element is transferred to the second portion of the heat conducting element to the outside air. C l- ON C e~ Cn Clq WMll VIVI vvvvva) Clq

Description

A HEAT TRANSFER ARRANGEMENT FOR IMPROVED ENERGY EFFICIENCY OF AN AIR CONDITIONING SYSTEM FIELD OF THE INVENTION [001] This invention relates to an arrangement adaptable to a conventional air conditioning system that offers improved energy efficiency by minimising required power consumption of the compressor of the air conditioning system. BACKGROUND ART DISCUSSION [002] It is well recognised that the function of the compressor/condenser unit of an air conditioning system is to compress the refrigerant vapour out of the evaporator that was responsible for cooling the room, and condense back to a liquid refrigerant state. In the condenser, the condensation heat of the refrigerant is discharged into outdoor air or the cooling water or any other heat sink. Nonetheless for the heat taken from the conditioned space through the evaporator of the air conditioner to flow into the outdoor air or atmosphere, the condenser temperature must be raised above outdoor ambient temperature for the flow of heat from the condenser coils into the outdoor air. [003] As is therefore to be expected when the outdoor ambient temperature becomes higher, notably during hot summer conditions, the compressor that is required to compress the low pressure refrigerant gas to a high pressure at the higher temperature needs to work much harder and to utilise substantially more energy through power consumption as it needs to raise the refrigerant temperature above the high outdoor hot summer temperatures if, as is required, there is going to be a flowing away of the heat to the outside air. In other words, in a hotter day, the air conditioner would consume more energy to remove the same amount of heat from the conditioned space to the outside (ambient) namely the air conditioner works at lower efficiency. [004] It would be advantageous therefore to lower the condenser's temperature as much as possible. That's why normally a water cooled air 1 conditioner has better energy efficiency than an air cooled one. However if no running cooling water or cooling tower available, water cooling (to an air conditioner) is not easily possible. While others in the past have connected the condenser of an air conditioning system to, say for example a (static) water tank, as is to be expected over time this water tank will also increase in temperature, would soon establish a temperature not so different to the outdoor summer temperature or even higher depending on the size of the water tank. When the water tank temperature is close or higher than the outdoor air temperature, the advantage of water cooling is no longer valid. [005] It would be advantageous particularly in locations where there is significant temperature fluctuations between day and night wherein these temperature fluctuations could somehow be utilised in order to maintain the water tank temperature always lower than the outdoor air temperature, ie. maintain the air conditioner working at a higher efficiency. [006] It is an object of this invention to provide a heat transfer arrangement in association with a fluid tank, which will be able to provide improved energy efficiency of a conventional air conditioning system by taking advantage of daily temperature fluctuations between day and night. Thereby providing significant energy savings to the air conditioning system while delivering the desired temperature to the users of the air conditioner. SUMMARY OF THE INVENTION [007] Accordingly in one form of the invention there is provided a heat transfer arrangement for improved energy efficiency of an air conditioning system, said arrangement including; an insulated underground or above ground fluid tank; a heat conducting element having a first portion at least partially submersible with the fluid of the underground or above ground fluid tank and a second portion of the heat conducting element exposed to the outside air and/or external atmospheric temperature conditions; cooling coils of a condenser of the air conditioning system substantially submersible in said fluid from or of the 2 underground fluid tank such that when an air conditioning compressor of the air conditioning system compressing the refrigerant resulting in increased pressure and temperature, the refrigerant gas is then passed into the cooling coils of the condenser which is submersed in the fluid of the underground or above ground fluid tank results in the generated heat of the compression flowing into the fluid and then subsequently into the heat conducting elements which, as said heat conducting elements are also exposed to the outside air sees the transfer of heat from the fluid within the underground or above ground fluid tank out through the heat conducting element into the outside air. [008] In a further form of the invention there is provided a heat transfer arrangement for improved energy efficiency of an air conditioning system, said arrangement including; an insulated underground or above ground fluid tank; a heat pipe or a group of heat pipes having a lower portion at least partially submersible with the fluid of the fluid tank and a upper portion of the pipe(s) exposed to the outside air and/or external atmospheric temperature conditions; cooling coils of a condenser of the air conditioning system are placed in a (small) water tank, the water in which is connected/circulated with the (big) underground or above ground water tank that is equipped with the heat pipe(s), refrigerant vapour put out by the compressor transfers condensation heat through the cooling coils of the condenser and the small water tank to the water in the (big) tank, when the air conditioner is running, wherein the heat will gradually increase the temperature of the water in the (big) tank if the air conditioner keeps running. [009] The invention is an automatic/passive mechanism to release the heat from the (big) water to the ambient as long as the (big) water tank's temperature is higher than the ambient temperature. [010] The invention/mechanism can make sure the heat transfer in opposite direction, ie. ambient to water tank never occurs even the ambient temperature is higher than water tank temperature, which is submersed in the fluid of the underground fluid tank results in the generated heat of the compression flowing 3 into the fluid and then subsequently into the heat conducting elements which, as said heat conducting elements are also exposed to the outside air sees the transfer of heat from the fluid within the underground fluid tank out through the heat conducting element into the outside air. [011] Advantageously the daily ambient temperature fluctuation is utilised effectively each night, through the simple mechanism/heat pipe(s)without any input of energy, the underground fluid tank is being cooled. In other words, the big underground water tank's temperature, which was increased due to the running of the air conditioner the previous day, can be restored to its original temperature by next morning. [012] Thus the air conditioner can run at higher efficiency with the lower condenser temperature again in the following day. The inventive feature of the heat conducting element provides a unique link between the underground fluid tank and external outside conditions taking advantage of temperature fluctuations so that as long as the outside temperature is lower than the temperature of the fluid tank, the heat can be efficiently transferred out of the fluid tank. [013] As is to be expected however, as the day wears on the temperature of the fluid tank will gradually rise and while the energy consumption of the heat pump compressor will have to increase in order to raise the refrigerant temperature to be above those temperatures of the fluid inside the fluid tank it will still be substantially lower than those temperatures experienced at the same time of the day outside. [014] Advantageously as introduced above, at night when the temperatures become much cooler, particularly in those locations that are subjected to desert like conditions of hot sunny days and clear skies in the evening resulting in a significant drop in temperature, this drop in temperature is then utilised through the heat transfer element to release the heat which has slowly accumulated 4 within the fluid of the underground fluid tank during the daily operation of the air conditioning system. [015] In preference the heat transfer element includes a series of hollow pipes arranged in columns supported side by side. [016] In preference each pipe includes a plurality of radial or lateral fins that extend out along the length of the column. [017] Advantageously the arrangement of the heat conducting elements as a series of hollow metal column equipped with fins provides for a unique heat pipe exchanger which has high conductivity and releases heat from the underground fluid tank to the outside atmosphere uni-directionally. [018] In preference the hollow metal columns or pipes are partly filled with fluid and are supported to a defined depth within the underground fluid tank. [019] In preference the fluid is water or other fluids, depending on the climate of the location. [020] In an alternative embodiment of the invention the metal pipes of the heat transfer element could also be used to provide support for a roof structure above the underground fluid tank. [021] An advantage of such an arrangement is that not only can the heat transfer elements provide the functionality of being able to transfer the heat away from the underground fluid tank during the temperature fluctuations of the evening and cooler nights but also provide a means by which a physical structure can be constructed above the water tank. [022] For example the metal pipes can provide the upright supports for a carport roof or similar such structural arrangement. 5 [023] In preference the arrangement includes a plurality of underground fluid tanks, each with their own heat conducting element. [024] An advantage of such arrangements is that depending on the size of the air conditioning system the heat transfer arrangement can become modulated adding additional underground fluid tanks that could be inter-connected to work in combination with one another and the compressor/condenser unit of the air conditioning system. [025] The ability to modulate the underground fluid tanks and also the use of the heat conducting elements as features that can assist in support structures above the underground fluid tanks means that whole sections of areas can be under-pinned by the modulated underground fluid tanks each having their own above ground structure, which introduced above, could include a carport. [026] Advantageously the modulated underground fluid tanks can serve their purpose to work in combination with the compressor/condenser unit but also provide ground support for an overlayed pavement, roadway, carpark and so forth. [027] In preference the constructed carport roof includes solar panels. [028] As introduced above this unique heat transfer arrangement will work optimally in those locations where daily temperature fluctuations between day and night are reasonably significant. [029] In places such as Australia, South Africa and much of Asia many enterprises including mining, educational and health facilities need to be placed in remote locations that are subject to very high daily hot temperatures. [030] Accordingly these types of places require an air conditioning system providing as much comfort as possible to those having to live and work in such harsh conditions. 6 [031] Advantageously this invention will provide significant energy savings to such air conditioning systems but also at the same time not only reduce power consumption but also provide the spin-off of having extra benefits of being able to establish dual purpose usage of the underground fluid tanks which will offer support for pavement, roadways, carparks and so forth above and to which the heat conducting elements extending out from the underground fluid tanks would then provide support means for above ground constructions such as carports to which further energy efficient items such as solar panels and so forth can then be placed thereupon. [032] In order to now describe this invention in greater detail a preferred embodiment will be presented with the assistance of the following illustrations and accompanying text. BRIEF DESCRIPTION OF THE DRAWINGS [033] Figure 1 is a schematic representation of the heat transfer arrangement being used in combination with the compressor/condenser unit of a conventional air conditioning system. [034] Figure 2 is a schematic illustration of a further embodiment of the invention wherein the structural features of the underground fluid tank and the heat conducting elements of the invention are used for additional construction applications. DETAILED DESCRIPTION OF THE INVENTION [035] Referring to the drawings now in greater detail wherein as shown generally by way of (10) a heat transfer arrangement is in communication with the compressor (12) and condenser unit (14) of a conventional air conditioning system. [036] The heat transfer arrangement (10) includes an underground insulated fluid tank (16), which in this preferred embodiment contains the fluid of water. 7 The tank (16) is placed shallowly under the ground (30). The fluid (28) is surrounded by tank (16) insulation (29). [037] The heat conducting element responsible for transferring heat from the fluid (28) of the underground water tank (16) out into the outside air shown generally as (20) includes a series of hollow metal pipes (22) which include a first section (26) which is submersed within the fluid (28) of the underground water tank (16) and a second portion (27) which extends out above the ground (30). [038] Each metal column pipe (22) includes a plurality of fins (25) which assist in radiating the heat out from the heat conducting element (10) in all directions into the outside air, shown by way of arrows (33). [039] The compressor (12) and condenser unit (14) are working in combination with the underground fluid tank (16) and notably the temperature of the fluid (28) contained within the tank (16). [040] In order for the air conditioning system to function correctly the compressor pump will be required to compress the low pressure refrigerant gas to a high pressure and a high temperature raising the refrigerant temperature above the outside air temperature. [041] Nonetheless in this embodiment the compressor (12) will only need to compress the incoming refrigerant of the air conditioning system to a high pressure gas at a temperature which only needs to be above that of the temperature of the fluid (28) within the underground fluid tank (16). [042] The reason being is that the condensing coil (18) of the condenser unit is submersed within the fluid (28) of the underground fluid tank (16). [043] Therefore initially heat is flowing from the condenser coils (18) out into the fluid (28) of the underground tank (16) instead of to the outside air, which in 8 the case of hot summers would be much higher than the temperature of the fluid (28) in the underground tank (16). [044] As the compressor/condenser unit is working in combination with the underground tank (16) rather than the outside air directly it needs not consume as much power as the temperature of the refrigerant need not be raised to those levels expected of the outdoor summer heat. [045] Significantly in locations where there is temperature fluctuation between day and night the cooler temperatures of the evening and night then see heat being radiated away through the heat conducting element (20) to the outside air. [046] Therefore effectively during the evening when temperatures have been reduced significantly from those of the hot summer day, there is a significant heat transfer between the fluid (28) and the outside air. [047] During the evening and night the fluid (28) within the underground tank (16) is being cooled through the use of the heat conducting element (20) so as to provide a cooled fluid (28) which when the air conditioning system again becomes operational during the day can then interact with those cooled fluid (28) temperatures now of the underground tank (16). [048] Advantageously by recognizing temperature fluctuations and using this phenomenon in combination with the heat conducting element (20) by having it partially submersed in the fluid (28) of the underground tank (16) and another section exposed above the ground avoids the continual build up of heat within the fluid (28) of the underground tank (16). [049] Advantageously heat is able to be removed from the fluid (28) during the evenings and night, in effect replenishing the cool conditions of the fluid (28) of the underground tank (16) for subsequent use the following day. 9 [050] Figure 2 shows a further preferred embodiment of the invention simply taking the inherent structural features of the underground tank (38) and the heating elements (42) submersed within the fluid (39) of the underground tank (38) to act as construction supports when also being utilised for a heat transfer arrangement for improved energy efficiency of the air conditioning system with which the arrangement is working. [051] As can be seen in the general embodiment shown by way of (36) the underground tank (38) provides a structural support and base for the above pavement and/or carpark (41) wherein the heat conducting elements (42) partially submerged within the fluid (39) of the underground (38) are still adapted to take away the heat passed into the fluid (39) through the condenser coil (40) but at the same time the heat conducting elements (42) act as structural support for a carport roof (44) for vehicle (43). [052] The carport roof (44) also offers the opportunity of additional solar panels (46) and so forth to be placed upon the structure. [053] Advantageously not only does the arrangement provide a heat transfer mechanism to improve energy efficiency of an air conditioning system, but also provides dual purpose for construction applications within the environment that it is placed in. 10

Claims

1. A heat transfer arrangement for improved energy efficiency of an air conditioning system, said arrangement including; an underground and/or insulated fluid tank; a heat conducting element having a first portion at least partially submersible with a fluid of the underground and/or insulated fluid tank and a second portion of the heat conducting element exposable to outside air; cooling coils of a condenser of an air conditioning system substantially submersed in said fluid of the underground and/or insulated fluid tank such that when an air conditioning compressor of the air conditioning system compresses a refrigerant this provides for a heated refrigerant, wherein the heated refrigerant is then passable into the cooling coils of the condenser wherein the heated refrigerant heats the fluid in the underground and/or insulated fluid tank, wherein the heated fluid subsequently transfers heat from the fluid to the first portion of the heat conducting element and whereby heat from the first portion of the heat conducting element is transferred to the second portion of the heat conducting element to the outside air.

2. The heat transfer arrangement of claim 1 wherein the fluid tank is underground and insulated.

3. The heat transfer arrangement of claim 1 wherein the fluid tank is insulated and above ground.

4. The heat transfer arrangement of claim 1 wherein the heated refrigerant passed into the cooling coils of the condenser is a heated refrigerant gas. 11

5. The heat transfer arrangement of claim wherein the heat conducting element includes a series of hollow pipes arranged in columns supported side by side.

6. The heat transfer arrangement of claim 5 wherein each hollow pipe includes a plurality of radial or lateral fins that extend out along part of a length of each hollow pipe.

7. The heat transfer arrangement of claim 6 wherein the plurality of radial or lateral fins that extend out along part of the length each hollow pipe represent the second portion of the heat conducting element.

8. The heat transfer arrangement of claim 5 wherein the series of hollow pipes arranged in columns supported side by side are partially filled with fluid.

9. The heat transfer arrangement of claim 8 wherein the fluid is water.

10. The heat transfer arrangement of claim 5 wherein the series of hollow pipes arranged in columns supported side by side provide support for a roof structure above the underground and/or insulated fluid tank.

11. The heat transfer arrangement of claim 10 wherein the roof structure includes solar panels. 12