REFROIDISSEMENT RAC

RAC COOLING

Abrégé français

Une méthode de refroidissement d'un transformateur immergé dans l'huile ou d'une machine électrique par transfert thermique vers un gaz liquéfié, par exemple du fréon. Un premier échangeur thermique transfère de la chaleur entre de l'huile et du gaz liquéfié, qui circule dans un circuit de thermopompe fermé ayant un cycle d'évaporation. Enfin la chaleur est éliminée par débit d'air. Ceci est réalisé soit par l'utilisation d'un refroidisseur externe ou à distance contenant un échangeur thermique en communication avec une unité de réfrigération classique sur une remorque ou toute méthode applicable fixe ou mobile à placer près du transformateur, ou en plaçant directement l'échangeur thermique et/ou un serpentin d'évaporateur préfabriqué dans le boîtier du transformateur raccordé au refroidisseur externe. Ma nouvelle unité de refroidisseur d'huile et de transformateur peut être appliquée aux transformateurs existants ou peut être intégrée dans une nouvelle conception et fabrication de transformateurs électriques, pour améliorer le contrôle de la température, et mieux refroidir la zone réactive dans les transformateurs. Il s'agit d'un système pratique et rentable pour refroidir les transformateurs électriques, en particulier dans des conditions extrêmes dans lesquelles il va stimuler la production des transformateurs et améliorer son efficacité. Mon système n'était pas disponible précédemment. Mon invention est une méthode de refroidissement liquide (huile) - gaz, à ne pas confondre avec les méthodes actuelles de refroidissement liquide - liquide ou gaz - gaz.

Abrégé anglais

Method of cooling oil immersed transformer or an electrical machine by heat transfer to a liquefied gas, e.g. Freon. A first heat exchanger transfers heat from oil to liquefied gas, which circulates in a closed heat pump circuit with an evaporating cycle. Finally heat is removed by airflow. This done by either using external or remotely cooler unit containing heat exchanger in communication with conventional refrigeration unit on trailer or any fixed or movable applicable method to locate near Transformer, or by directly locating the heat exchanger and/or pre-engineered evaporating coil within the transformer housing connected to outside refrigeration unit. My new Transformer Oil cooler unit can be applied to existing transformers or can be adopted in new design and manufacturing of electrical Transformers, which can have better temperature control, and better cooling for the hot spot area in Transformers. This is a practical and cost effective system to cool electrical Transformers particularly under extreme conditions in which it will boost the transformers output and enhanced its efficiency. My system has not been previously available. My invention is liquid (Oil) -to-Gas cooling method and not to be confused with current Liquid-to-liquid or any Gas-to-Gas cooling practice.

Revendications

Claims:
The embodiments of this invention in which an exclusive property or privilege
is claimed are
defined as follows and not limited to:
What is claimed is
1. A Process and method for cooling oil or liquid coolant for electrical
equipments using liquid to
gas transfer application function comprising: a heat exchanger housing with
inlet and outlets for
oil circulation; a oil circulation pump for circulating the oil; a heat
exchanger unit for liquid to gas
heat transfer function by liquid to gas circulation; a heat pump with fan
assembly; a
conventional refrigeration and heat exchanging unit for heat exchange between
the oil and the
gas; an evaporator coil for completing the refrigeration cycle; a control
panel for controlling the
RAC (Rafic AC) cooling system; cooling system includes cooling oil immersed
transformer or an
electrical machine by pumping oil from electrical equipment to the heat
exchanger and
transferring heat from oil to liquid gas circulating in a closed heat pump
cycle with an
evaporating cycle for reducing the temperature of oil.
2. The process and method for cooling oil for electrical equipments using
liquid to gas transfer
application function as per claim 1 comprises a cooling unit that is remotely
controlled.
3. A Process and method for cooling oil for electrical equipments using liquid
to gas transfer
application function as per claim 1 comprises a cooling unit which is integral
to the electrical
equipment.
4. A Process and method for cooling oil for electrical equipments using liquid
to gas transfer
application function as per claim 1 comprises a cooling substance which is
Freon, Helium,
Hydrogen or any other refrigerant gas.
5. A Process and method for cooling oil for electrical equipments using liquid
to gas transfer
application function as per claim 1 comprises cooling of oil or any other
dielectric substance.
6. A Process and method for cooling oil for electrical equipments using liquid
to gas transfer
application function as per claim 1 comprises inlets and outlets equipped with
quick connect
couplings.
7. A Process and method for cooling oil for electrical equipments using liquid
to gas transfer
application function as per claim 6 comprising inlets and outlets equipped
with quick connect
couplings, which are manually or electrically operated.
8. The process and method for cooling oil for electrical equipments using
liquid to gas transfer
application function as per claim 1 where the cooling pump is a single or
three phase pump.
9. The process and method for cooling oil for electrical equipments using
liquid to gas transfer
application function as per claim 1 comprises the heat exchanger housing with
a drainage
system.

10. The process and method for cooling oil for electrical equipments using
liquid to gas transfer
application function as per claim 1 comprises the control panel for
controlling the refrigeration
cycle, which is local or remotely controlled.
11. The process and method for cooling oil for electrical equipments using
liquid to gas transfer
application function as per claim 10 , the control panel comprises a sensor
for measuring and
controlling the oil temperature.
12. The process and method for cooling oil for electrical equipments using
liquid to gas transfer
application function as per claim 10 , comprises a evaporator coil made from a
conventional
finned radiator or any applicable type coil.
13. The process and method for cooling oil for electrical equipments using
liquid to gas transfer
application function as per claim 1 or 2, the cooling unit comprises a
compressor of any
applicable design.
14. The process and method for cooling oil for electrical equipments using
liquid to gas transfer
application function as per claim 1 or 2, the heat pump comprising a condenser
unit and a fan
assembly of any applicable design.
15. The process and method for cooling oil for electrical equipments using
liquid to gas transfer
application function as per anyone of claims 1 to 14, the RAC cooling system
can be mounted
on a trailer or any moveable structure.

Description

CA 02435505 2004-06-10
Description
BACKGROUND OF THE INVENTION
[~Ol ] 1. Field of the invention
[0002] The invention pertains to cooling systems by Liquid (Oil) to Gas
circulation
method and refrigeration base of discussion for liquid (Oil) cooled electrical
Transformer and other applicable equipments.
[0003] 2. Description of the related Art.
[0004] In case of Electrical Transformer, large electrical Transformer
commonly
use a liquid coolant, usually Oil, to dissipate un favourable heat rise within
the
transformer housing during the operation of the transformer and sometimes from
outside weather condition. The coolant Oil may substantially fill the
transformer
housing and in most cases the liquid coolant action done by the thermodynamic
law of convection. Most today transformer may contain different shape of
design to define surface area to increase heat dissipation to the atmosphere,
mostly like radiator type. But when the transformer operate at maximum in some
and/ or additional heat rise impose on transformer from outside weather
specially during summer time, the temperature of the liquid coolant may reach
to undesirable temperature level, which threaten the transformer' operation
and
its life. Also the efficiency of the transformer goes lower. Additional
cooling
system for liquid coolant has been around the industry for quit some time.
Most
today practices around the world are done by Forced Air, Forced Oil, or forced
water separately of jointly. However, The cost and size of these systems and
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CA 02435505 2004-06-10
equipments are not cost effective and some time they are limited in efficiency
under extreme condition operation. This is why my invention RAC COOLING is the
most efficient system to practice in today and future, not only is cost
effective,
but best because is simple to adopt and will save great deal of energy loses
and
extend the life of very costly Transformers around Stations and substations
worldwide and more. With RAC COOLING invention new era of Transformer
cooling technology has been born and available. My invention is liquid (Oil)-
to-
Gas cooling not to be confused by any current liquid-to-liquid or Gas-to-Gas
cooling practice.
OBJECT OF THE INVENTION
[0005] The object of this invention is to provide a better cooling system and
method utilizing the conventional refrigerant cooling unit and practices used
for
lowering liquid (Oil) coolant temperature. The simplicity of RAC COOLING
Invention will allow providing better cooling practice to any exiting
electrical
transformer and can be done fixed to the transformer body or removable and
portable application and rapidly transported to location needed with
refrigeration unit quickly connected.
[0006) Another objective of this invention is to provide a cooling system and
method for liquid cool electrical transformer when designed and build with
minor
modification to transformer housing. This will pave the way to smaller in size
transformer based on new power delivery setting based on new temperature
rise sefifiing of Electrical transformers.
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CA 02435505 2004-06-10
SUMMARY OF THE INVENTION
[0007] The concepts of the invention could be practiced on wide range of
Liquid
coolants. While most of electrical operated transformer has Oil coolant, the
Oil is
in contact with transformers Coifs; the Oil coolant absorbs the temperature
rising
from the heat generated within the transformer from transformer operation and
from maybe additional outside heat imposed on transformer in hot weathered
area and from any heat waves that suppresses the design criteria of the
transformer. As said before, many design of transformer being practiced to
increase the size of the coolant circulation and heat dissipation by coolant
convection circulation and some time additional pipe opining is available to
dissipate the extra heat to atmosphere. Forced Oil. Forced Air, and/or Forced
water in additional to pumps and other equipments in many cases are being
practiced to aid the cooling of the transformer. Best of today available based
on heat exchange Liquid-to-liquid methods, but it is costly and not practical
in
many cases. Also my invention not to be confused with any current practice of
Gas -to-Gas cooling for transformer with SF6 gas.
[0~8] With RAC COOLING invention practice, the transformer coolant is exposed
to heat removing abilities of a heat exchanger, what I call Cooling Tank also,
Where Both Oil and Gas circulate and the liquid receives coolant from
conventional refrigeration unit where Gas being circulated and compressed.
The expansion coil or radiator is located within the cooling tank or what said
heat exchanger where Oil liquid is circulating. The refrigerant will absorbed
the
heat in large quantity and dissipated to atmosphere through the refrigervtion
cycle. It is way more effective and more efficient than coolant circulation
and
exposition to ambient temperature. Most fans re circulate hot air and not much
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CA 02435505 2004-06-10
effective because air losses density when heat rise. RAC COOLING invention
permits coolants to be effectively cooled even under high ambient atmosphere
temperatures.
[0009j The cooling Tank or as referred to also as heat exchanger may be either
located along with the refrigeration unit adjacent to the transformer or the
heat
exchanger be located within the transformer housing connected to the outside
refrigeration unit. If desired cooling Tank not needed, cooling area would be
better representation where liquid cooling circulation taking place while oil
circulation is happening by convection refrigerant in its circulation from
refrigeration cycle. In case Heat exchanger located outside the Transformer,
minimal modification to transformer housing required. Mostly connect conduit
mostly the inlet and outlet for
Oil circulation. While In case if Cooling Tank desired to be within the
Transformer
housing, modification required to host the new unit or additional items, again
is
not substantial it is simple to adopt.
[001 Oj RAC COOLING invention allows engineer and technician around the word
to design and built their transformer cooler unit as they desire and as they
see fit
for their applications, this is additional flexibility offered with RAC
COOLING
invention. For already existing transformer a portable unit on back of truck
or
trailer or any other movable equipment. With using quick-connect couplings and
flexible hoses may be connected fast to transformer inlets and outlets. Single
refrigerant unit could be used to cool down multiple transformers, or
alternate
between transformers as situation required.
[001 1 j With RAC COOLING Invention little engineering work required as the
heat
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exchanger unit and the refrigeration unit is conventionally constructed. Even
with build in heat exchanger within the transformer, no major design changes
required when adoption to the new system with currently design practices
available with skilled personal in transformer manufacturing industries or
related
fields.
BRIF DESCRIPTION OF THE DRAWINGS
[0012] FIG.I is a schematic view of the embodiment of the invention, which can
be described as block diagram presenting the invention system process.
[0013] FIG.2 is a schematic view of an embodiment of the invention wherein the
heat exchanger or as described cooling tank is located outside the transformer
housing.
[0014] FiG.3 is a schematic view the embodiment of the invention, wherein the
heat exchange area or cooling area or media is within the transformer housing.
[0015] FIG.4 is a schematic view the embodiment of the invention wherein the
heat exchanger and the refrigeration unit shown mounted on portable trailer or
moving equipment.
DESCRIPTION OF THE PREFERED EMBODIMENTS
[0016] The file of this patent contains at least 4 drawings. More drawing
would be
added and amended as required. The patent office to contain all drawings in
colour or black and Wight, and would be available upon request and necessary
fees paid. While this invention is susceptible of embodiment in many different
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CA 02435505 2004-06-10
forms, there is shown in drawings and will herein be described in detail
preferred
embodiment Of the invention with the understanding that the present discloser
is
to be considered as an exemplification of the principles of the
invention and is not intend to limit the broad aspect of the invention to the
embodiments illustrated. The aforementioned objects and advantage of the
invention will be appreciated more from the following description and
accompanying drawings wherein:
[0017] FIG. 1 Is a block diagram viewing all base items relate to and
application
of RAC COOLING invention. The Transformer 1 or as said other equipment
contain Oil or other substance, Liquid Oil pump 2 and/or any accessories
related,
Cooling tank 3 or as mentioned also heat exchanger unit, Refrigeration cycle 4
or as described conventional refrigeration unit with all related accessories,
Oil 5
or as said first substance or liquid coolant, Gas 6 or as said refrigerant Gas
and/or
as said second substance in circulation within heat exchanger, Evaporating
Coil
7 or as said other description Finn Radiator or similar item, Control panel 8
and/or
and additional control to complete the operation of the said system such as
temperature sensor, pressure gauges, flow meters etc... including locale or
any
remote control, Unit structure 9 or any preferred method to build and adopt
the
invention in its application including fixed , build within or portable shape
and
application.
[0018] FIG. 2 Is a schematic view of the embodiment of the invention wherein
the cooling tank or said heat exchanger is located externally of the
Transformer
having liquid coolant. The Refrigeration unit is illustrated at 44 and is
communicating with the cooling Tank 46. The Transformer 48 is connected by a
conduit system 50 with the heat exchanger 46; the conduit 58 contains the
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CA 02435505 2004-06-10
coolant returning system adjacent the inlet and outlet ports of the heat
exchanger. Arrows on FIG 4 indicate the direction of coolant. The pump 51 and
valves 52-1,52-O and Quick-disconnect coupling if desired 54-I and 54-O may be
incorporated into the heat exchanger unit, as may be the case with the
embodiment of FIG.4, and it will appreciate that the operation of system of
FIG.4
is identical to the operation of the apparatus shown in FIG.2. The transformer
inlet
and outlet valves with Quick-disconnect coupling are being identified in this
drawing as 57-1,57-0,56-I and 56-O.
[0019] FIG.3 is another embodiment of RAC COOLING Invention schematically
show the transformer 64 being constructed to house and adopt the heat
exchanger unit or as said cooling area or cooling panels 66. It is relatively
simple
modification with today skilled transformer manufacturer and personal that
work
in this field. The heat exchanger part will absorb the heat and suck it to
outside
the transformer with the circulation and refrigeration unit 62 adopted outside
the
transformer. 71, 72, 73, 74, 76 and 78 are accessories related to complete
safe
operational refrigeration cycle or system, such as but not limited to valves,
refrigeration conduits, etc... In this practice the new cooling method and
system
could do without pump and additional valves if desired or as per engineering
designer see fit and cost effective, because the liquid coolant will be
circulated
through the convection from heat rise within the Transformer housing.
[0020] FIG. 4 in this schematic The said portable new Transformer cooler unit
as I
have given number RAC-TC-A shown in better explanation but not limited to this
design, it is to be understood clearly that many portable cooler unit based on
the embodiment of RAC COOLING invention may be used and applied. The
cooling tank or as said heat exchanger unit 28 show the evaporating coil or as
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CA 02435505 2004-06-10
said Finn radiator to cool and lower the temperature of the liquid coolant
being
circulated in conduits system 40 and 42. Arrows shows the flow direction. The
inlet
of cooling tank 34-1 show connected to outlet of transformer 20 as given
number 36-O. The inlet of transformer 36-I is showing connected to outlet of
heat
exchanger 28 through 34-O. Pump 35 show in fine with Liquid coolant
circulation,
pump 35 may be in inlet side or outlet side of heat exchanger unit. The
conventional refrigeration unit 26 is show in connection to heat exchanger
unit
28. Control panel 25 show in communication with temperature sensor and any
additional desired control items locally or remotely. Grounding 27 for safety
of
personal and equipment show in schematic. Item 24 is trailer, back of truck or
even applicable wheel barrel or any applicable movable structure to adopt all
said items per said embodiments may be used. One cooler unit could be used to
cool more than one transformer.
[0021 ] While the specific disclosed embodiments have been illustrated and
described, numerous modifications come to mind and may be apparent to
those skilled in the art without departing from the sprit and scope of the
invention. From above description also to be underlined and understood that
singular can be referred to as plural, feminine as masculine and items
described
are not limited to any shape, made, material, size, type, number or colour and
can be found and used from already existing conventional materials available
in
market or new designed and/or manufactured items to fulfill the sprit of the
invention.

Dessin représentatif