U.S. patent application number 13/502421 was filed with the patent office on 2012-08-16 for cooling device for cooling medium-voltage apparatus using insulated heat pipes.
This patent application is currently assigned to ALSTOM TECHNOLOGY LTD. Invention is credited to Denis Frigiere, Didier Rodrigues, Jean-Marc Willieme.
Application Number | 20120205074 13/502421 |
Document ID | / |
Family ID | 42263928 |
Filed Date | 2012-08-16 |
United States Patent
Application |
20120205074 |
Kind Code |
A1 |
Frigiere; Denis ; et
al. |
August 16, 2012 |
COOLING DEVICE FOR COOLING MEDIUM-VOLTAGE APPARATUS USING INSULATED
HEAT PIPES
Abstract
The cooling device is suitable for fitting to existing
installations, without redesigning them. It consists in using heat
pipes (12) that are partly embedded in the casing (10) of the
apparatus. This embedded portion (12A) of the heat pipe (12)
penetrating into the casing (10) has a sleeve (14) that is both
electrically insulating and a good conductor of heat. The device is
for application to circuit breakers in a medium-voltage,
high-amperage electrical installation.
Inventors: |
Frigiere; Denis; (Decines,
FR) ; Rodrigues; Didier; (Serpaize, FR) ;
Willieme; Jean-Marc; (La Mulatiere, FR) |
Assignee: |
ALSTOM TECHNOLOGY LTD
Baden
CH
|
Family ID: |
42263928 |
Appl. No.: |
13/502421 |
Filed: |
October 25, 2010 |
PCT Filed: |
October 25, 2010 |
PCT NO: |
PCT/EP10/66011 |
371 Date: |
April 17, 2012 |
Current U.S.
Class: |
165/104.26 |
Current CPC
Class: |
H01H 2009/523 20130101;
H01L 2924/0002 20130101; H01H 9/52 20130101; H01L 2924/0002
20130101; H01L 2924/00 20130101; F28D 15/0266 20130101; H01L 23/427
20130101; H01H 2009/526 20130101 |
Class at
Publication: |
165/104.26 |
International
Class: |
F28D 15/04 20060101
F28D015/04 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 26, 2009 |
FR |
0957482 |
Claims
1. A cooling device using a phase-change heat-transfer fluid for
medium-voltage apparatus, comprising: at least one heat pipe (12,
42A, 42B); the device being characterized in that the at least one
heat pipe (12, 42A, 42B) penetrates in part into the apparatus and
is electrically insulated in this embedded portion (12A) by means
of a sleeve (14) that is both electrically insulating and a good
conductor of heat.
2. A device according to claim 1, characterized in that the
electrically insulating sleeve (14) is made of sintered aluminum
nitride.
3. A device according to claim 1, characterized in that the
electrically insulating sleeve (12, 42A, 42B) is made of sintered
boron nitride.
4. A device according to claim 1, the assembly being placed inside
a sheath (22), the device being characterized in that the outside
portion (12B) of the heat pipes (12, 42A, 42B) not penetrating into
the apparatus terminating at the condensers (24) possesses an
electrically insulating sleeve (18).
5. A device according to claim 1, characterized in that each heat
pipe (12) possesses an electrically insulating ring (16) placed on
an outside portion (14A) of the electrically insulating sleeve
(14).
6. A device according to claim 1, characterized in that each heat
pipe (12, 42A, 42B) possesses an electrically insulating sleeve
(18) on its outside portion.
Description
FIELD OF THE INVENTION AND DEFINITION
[0001] The invention relates in particular to the field of circuit
breakers or disconnectors for medium-voltage generators, placed in
a protective sheath, and using cooling devices called "heat pipes"
that operate with a phase-change heat-transfer fluid.
[0002] It should be recalled that a heat pipe is presented in the
form of a long hermetically-sealed enclosure containing a fluid
with its gaseous phase and its liquid phase in equilibrium, in the
absence of any other gas, ignoring traces.
DEFINITION
[0003] Heat pipe: Thermal apparatus in the form of a long
hermetically-sealed enclosure containing a fluid with its gaseous
phase and its liquid phase in equilibrium. Heat is transferred from
the hot portion to the cold portion of the tube by vaporizing the
liquid phase and condensing the vapor in the cold portion.
PRIOR ART AND PROBLEM POSED
[0004] The constant concern of makers of that type of equipment is
to increase the ability of such apparatuses to conduct higher and
higher currents, in particular for circuit breakers and
disconnectors placed inside busbars at the outlets of power
stations for producing or distributing electricity. That applies
particularly for alternator circuit breakers.
[0005] A method that is generally used consists in making more
uniform the temperature of the air that is in contact with the
various heating and heated parts of the circuit breaker concerned.
The cooling inside such a protective sheath may take place by
natural or forced convection of the air enclosed therein and in
which the circuit breaker is to be found, the prevailing
temperature inside the protective sheath being considerably higher
than the prevailing temperature outside, by 30.degree. C. to at
least 40.degree. C.
[0006] Another solution consists in providing an increase in the
current flow section in the various transmission elements, and thus
increasing the size of circuit breaker parts.
[0007] Patent document EP 1 657 731 describes a known cooling
device and method for cooling a high-voltage disconnector or a
circuit breaker. FIG. 1 shows, in section, an embodiment described
in that document. FIG. 1 mainly shows a medium-voltage conductor 2
or the casing of a circuit breaker. It is surrounded by evaporators
3 forming part of a cooling assembly 1 therefor. Such an assembly
is accompanied by an insulating sleeve 7 surrounding a device
operating with a phase-change heat-transfer fluid 5 in order to
evacuate the heat collected by the evaporators 3. A flexible sleeve
9 completes the assembly. The various parts are placed together
inside a protective sheath 8. The cooling assembly opens out to the
top of this protective sheath 8 leading to a condensation device 4,
e.g. with fins.
[0008] The object of the invention is to propose a different
solution for this type of device.
SUMMARY OF THE INVENTION
[0009] To this end, the invention mainly provides a cooling device
using phase-change heat-transfer fluids for medium-voltage
apparatus and comprising at least one heat pipe.
[0010] According to the invention the heat pipe(s) is/are placed in
such a manner as to penetrate in part into the apparatus and is/are
electrically insulated, in this embedded portion, by means of a
sleeve that is both electrically insulating and a good conductor of
heat.
[0011] In a first possible embodiment of the invention, the sleeve
is made of sintered aluminium nitride.
[0012] In a second embodiment, the sleeve is made of sintered boron
nitride.
[0013] Preferably, the outside portion of the heat pipe(s) riot
penetrating into the apparatus terminating at a condenser is
provided with an electrically insulating sleeve.
[0014] Each heat pipe may possess an electrically insulating ring
on an outside portion of the electrically insulating sleeve.
[0015] In addition, each heat pipe may possess an electrically
insulating sleeve on its outside portion.
LIST OF FIGURES
[0016] The invention and its various technical characteristics can
be better understood on reading the following description of three
embodiments of the invention. The description is accompanied by six
figures in which, respectively:
[0017] FIG. 1 shows a prior art cooling device;
[0018] FIG. 2, partially in section, shows the technology used in
the device of the invention;
[0019] FIGS. 3A, 3B and 3C are cross-sections showing three
embodiments of the invention; and
[0020] FIG. 4 is a longitudinal section showing the device of the
invention, in particular that shown in FIG. 3C.
DETAILED DESCRIPTION OF THREE EMBODIMENTS OF THE INVENTION
[0021] FIG. 1 shows a portion of the casing 10 of a circuit
breaker, the casing having a certain thickness in which the heat
due to the flow of electricity at medium and high voltage and
amperage accumulates.
[0022] In FIG. 2, two heat pipes are shown penetrating in part into
the casing 10 of the circuit breaker.
[0023] In FIG. 2, the portion 12A of the heat pipe that is embedded
in the casing 10 of the circuit breaker is therefore heated. The
fluid in the heat pipe 12 vaporizes when accumulating the energy.
The gas is thus diffused inside the heat pipe 12 until it reaches
the non-embedded, opposite end 12B, where it condenses. The
embedded end 12A is surrounded by a sleeve that is both
electrically insulating relative to the casing 10 of the circuit
breaker and also a good conductor of heat. In particular, mention
may be made of the use of sintered aluminum nitride or of sintered
boron nitride in order to constitute the electrically insulating
sleeves 14.
[0024] As shown by the heat pipe 12 on the left, the assembly may
be completed by a ring made of electrically insulating material
that surrounds the outside portion 14A of the electrically
insulating sleeve in order to increase the creepage distance.
[0025] As shown by the heat pipe 12 on the left, the outside
portion 12B may also possess a second electrically insulating
sleeve 18 in order to increase the creepage distance.
[0026] With reference to FIG. 3A, a first embedment of such a
principle in a circuit breaker 20 is shown. In FIG. 3, in a common
vertical plane, two heat pipes 12 both have respective embedded
portions 12A that penetrate into the casing of the circuit breaker
20. The end of the outside portion 12B of each of these heat pipes
12 is surrounded by a system of fins 26 in order to form a
condenser 24 so as to enable the heat to dissipate outside the
enclosure 22 in which the circuit breaker 20 is placed.
[0027] Generally the liquid returns by gravity, thereby leading the
condenser 24 to be placed high up. If the inside of the heat pipe
12 is provided with channels, liquid return is accelerated by
capillary force, and this also enables the condenser 24 to be
placed lower down, while accepting a loss of efficiency.
[0028] In FIG. 3A, in vertical section, it should be observed that
the circuit breaker may be placed on an insulating support 28. In
addition, the condensers 24 are therefore placed on the roof of the
enclosure 22.
[0029] Both heat pipes 12, shown in FIG. 3A, are implanted in the
circuit breaker 20, in a slightly offset manner, one on each side,
so that their outside ends are further apart from each other. Thus,
they may reach condensers 24 that are placed relatively far apart
on the enclosure 22.
[0030] FIG. 3B shows an embodiment with the same elements as the
embodiment shown in FIG. 3A. However, a fan device 30 is provided
above the enclosure 22 in order to promote the flow of air through
the condensers 24, and more precisely to promote the flow of air
between the fins 26 thereof.
[0031] FIG. 3C shows a third embodiment that makes use of a third
heat pipe 42A, placed between the two laterally offset heat pipes
42B.
[0032] In the embodiment of FIG. 3C, each heat pipe 42A, 42B
terminates in at least one condenser 24.
[0033] FIG. 4 is a longitudinal section showing the manner in which
the heat pipes 42A, 42B may be implanted at various points along a
circuit breaker 20, or on other switchgear 50 associated with
circuit breakers 20 that are always placed inside an enclosure 22,
such as busbar section isolators, for example. Each heat pipe 42A
and 42B is always connected to a condenser 24 that is placed on the
roof of the enclosure 22.
[0034] The addition of suitable materials on the inside walls of
the heat pipes 12, 42A and 42B also makes it possible for the heat
pipes to be implanted upside down, and this increases cooling
potential.
[0035] The main advantage of such a device is that it adapts to
various heat pipe and cooling element technologies that have
already been tested, without needing to develop insulation methods
that need to contain the cooling liquid.
* * * * *