U.S. patent application number 11/220706 was filed with the patent office on 2006-03-09 for electrical installation comprising a decompression channel.
This patent application is currently assigned to Siemens AG. Invention is credited to Martin Eiselt, Gildo Mahn, Achim Milbich.
Application Number | 20060050470 11/220706 |
Document ID | / |
Family ID | 7679039 |
Filed Date | 2006-03-09 |
United States Patent
Application |
20060050470 |
Kind Code |
A1 |
Eiselt; Martin ; et
al. |
March 9, 2006 |
Electrical installation comprising a decompression channel
Abstract
The invention relates to an electrical installation, especially
a medium-voltage switchgear, comprising at least one encapsulated
function module (FM), a decompression channel (DK) which is
connected to said function module, and at least one in-flow opening
(EO . . . ) which connects the function module (FM) to the
decompression channel (DK). The covering surface (DF 1,2,3) of the
decompression channel (DK), opposite the inflow opening (EO . . .
), comprises at least one partial region which is obliquely
oriented in relation to the inflow direction. Hot gases and high
pressures produced during an accidental arc can thus be evacuated
from the installation, without any risk to humans and buildings.
Pressure channels are used, inter alia, in installations used in
relation to medium-voltage technique for providing and distributing
energy.
Inventors: |
Eiselt; Martin; (Grundau,
DE) ; Mahn; Gildo; (Linsengericht, DE) ;
Milbich; Achim; (Waghaeusel, DE) |
Correspondence
Address: |
MORRISON & FOERSTER LLP
1650 TYSONS BOULEVARD
SUITE 300
MCLEAN
VA
22102
US
|
Assignee: |
Siemens AG
Munchen
DE
|
Family ID: |
7679039 |
Appl. No.: |
11/220706 |
Filed: |
September 8, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10472597 |
Sep 22, 2003 |
|
|
|
PCT/DE02/00933 |
Mar 11, 2002 |
|
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11220706 |
Sep 8, 2005 |
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Current U.S.
Class: |
361/605 |
Current CPC
Class: |
H02B 13/025
20130101 |
Class at
Publication: |
361/605 |
International
Class: |
H02B 7/00 20060101
H02B007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 20, 2001 |
DE |
10114742.2 |
Claims
1-6. (canceled)
7. An electrical installation, comprising: at least one
encapsulated functional module and a pressure release duct
connected thereto; at least one inflow opening which connects the
functional module to the pressure release duct, a top surface,
which is opposite the inflow opening, of the pressure release duct
having at least one subarea which is aligned obliquely with respect
to the inflow direction, wherein the pressure relief duct has a
pressure relief opening directing a pressure wave via a chimney
system to an exterior of the installation.
Description
CLAIM FOR PRIORITY
[0001] This application is a continuation of U.S. application Ser.
No. 10/472,597 filed on Sep. 22, 2003, which is a 35 U.S.C. 371 of
PCT/DE02/00933, which was published on Sep. 26, 2002, which claims
the benefit of priority to German Application No. 10114742.2, filed
Mar. 20, 2001.
TECHNICAL FIELD OF THE INVENTION
[0002] The invention relates to an electrical installation, and in
particular to a medium-voltage switchgear assembly.
BACKGROUND OF THE INVENTION
[0003] For the protection of persons and of the installation,
medium-voltage switchgear assemblies are provided with apparatuses
for releasing pressure in order for it to be possible for the hot
gases produced in the event of an arc flashover to be dissipated
safety from the installation area. A number of functional modules
are usually used for these switchgear assemblies, the functional
modules being encapsulated with respect to one another and with
respect to the atmosphere such that the effects of an explosion in
the interior of the functional module cannot spread to the area
surrounding the installation. In the event of an arc forming in one
of these functional modules, the excess pressure produced by the
air suddenly being heated and the hot gases are dissipated such
that neither persons nor the installation are harmed or damaged in
any way. Pressure release ducts are usually provided for this
purpose and are connected to the individual functional modules by
means of a suitable valve system such that it is possible for the
excess pressure and the hot gases to be dissipated from the
affected functional module but at the same time such that it is not
possible for the hot gases or a pressure wave to enter the other
functional modules.
[0004] DE 31 25 364 A1 describes a pressure release duct which is
rectangular in cross section and in whose interior the hot gases
are first cooled by swirling and the excess pressure is reduced.
Then, the gases are dissipated from the installation via
ventilation slots such that they are thereafter only slightly
harmful.
[0005] In DE 195 20 698 A1 and DE 196 45 304 C1, the pressure and
temperature are reduced using so-called damping elements, in the
form of cartridges, which are installed either within the
installation or externally. The gases are in this case directed
away either via ventilation slots into the area of the building
surrounding the installation or to the outside via a chimney
system.
[0006] With all of these solutions it is possible, however, for the
pressure release duct having a rectangular cross section not to be
suitable for loads in the case of particularly intensive arc
flashovers.
SUMMARY OF THE INVENTION
[0007] The invention discloses dissipation of the high pressures
and temperatures which occur during an arc discharge without posing
a risk to persons and the installation, and to ensuring sufficient
robustness even for the case of intensive arc discharges and their
effects.
[0008] In one embodiment of the invention, the top surface, which
is opposite the inflow opening, of the pressure release duct has at
least one subarea which is aligned obliquely with respect to the
inflow direction. Obliquely is understood here to mean any
deviation from a right angle in comparison to the flow direction,
which results in the gas not being reflected exactly straight.
[0009] The advantages achieved by the invention are, firstly, that
the cross-sectional form described has greater static robustness
than the rectangular cross-sectional form since the cross-sectional
form described can be as close as desired to a round
cross-sectional form which is optimum for robustness. Optimum
robustness is achieved by the cross section having as few straight
surface areas as possible which can be susceptible to bending.
Secondly, the advantage of the design according to the invention is
that the pressure wave entering the pressure release duct through
the inlet opening is scattered on the cover surface which is
opposite the inlet opening by being reflected in different
directions. In this manner, extreme pressure peaks can largely be
ruled out by superimposing other pressure waves on them.
[0010] One advantageous embodiment of the invention provides for
the pressure release duct to have a trapezoidal cross-sectional
profile. The refinement in which the cross-sectional surface has a
trapezoidal form firstly provides great robustness and, secondly,
makes simple manufacture possible.
[0011] A further advantageous embodiment of the invention provides
for the pressure release duct to have sloped end regions. By this
means, the pressure wave which propagates in the longitudinal
direction of the pressure release duct is scattered and the
pressure peaks are leveled off.
[0012] A further advantageous embodiment of the invention is that
the top surface of the pressure release duct has at least one
sloping surface approximately opposite the inflow opening in the
inflow direction.
[0013] In this manner, the pressure wave entering the pressure
release duct through the inflow opening can be dispersed and thus
weakened right at the start.
[0014] A further advantageous embodiment of the invention provides
for the pressure release duct to have a pressure release opening to
the exterior of the installation. The pressure wave and the gases
produced are in this case either dissipated into a pressure- and
temperature-resistant area, in which there are no people, or are
directed outside via a chimney system. In this manner, reliable
dissipation is ensured without posing any risk to the installation
or people.
[0015] A further advantageous embodiment of the invention is for
the pressure release duct to be connected to the exterior of the
installation via an absorption element. The absorption element
reduces both the temperature and the pressure to such an extent
that the gases can be dissipated both into a pressure- and
temperature-resistant area or via a chimney system to the outside
and into the area directly surrounding the installation.
[0016] A further advantageous embodiment of the installation
provides for the pressure release duct to have ventilation openings
on its top surface which close in a pressure-tight manner in the
event of a pressure surge occurring in the pressure release duct.
This ensures that sufficient cooling air is dissipated from the
installation for normal operation of the installation. In the event
of an arc flashover with the occurrence of hot gases and high
pressures, the ventilation openings are closed by means of valves
and prevent the gases from escaping into the area surrounding the
installation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The invention is explained in more detail by exemplary
embodiments depicted in the figures. The invention is described in
more detail below.
[0018] In the drawings,
[0019] FIG. 1 shows a view of the cross section through a
functional module with a pressure release duct having a trapezoidal
cross section placed on top.
[0020] FIG. 2 shows a view of a plurality of adjoining functional
modules having a common pressure release duct.
[0021] FIG. 3 shows a view of the cross section through a pressure
release duct having a trapezoidal cross section.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The functional module FM shown in FIG. 1 is divided up into
a plurality of functional compartments FR 1, 2, 3. These
compartments are separated from one another in a gas-permeable
manner by partition walls SW 13, 23. In other designs, the
partition walls SW . . . can also separate the individual
functional compartments FR . . . from one another in a
pressure-tight manner. The individual functional compartments FR .
. . may be, for example, switching module compartments FR 1 having
power breakers LS, connection compartments FR 3 or busbar
compartments FR 2. The outer walls AW of the functional module FM
shown are closed off in a pressure-tight manner both from the area
surrounding the installation and from any further functional
modules FM . . . which may be adjacent. In the exemplary embodiment
shown, the inlet openings EO 1, 2, 3 to the pressure release duct
DK are on the top face of the functional module FM. In this case,
each functional compartment FR 1, 2, 3 has its own connection to
the pressure release duct DK such that a fault in one of the
functional compartments FR 1, 2, 3 does not have any effect on the
other functional compartments FR 1, 2, 3. The inlet openings EO 1,
2, 3 to the pressure release duct DK are closed in the exemplary
embodiment shown by valve systems KS 1, 2, 3 having a non-return
valve function such that gas can only flow from the functional
module FM, and not from the pressure release duct DK into the
functional module FM.
[0023] FIG. 2 shows, schematically and in longitudinal section, a
plurality of adjoining functional modules FM, FM . . . having a
common pressure release duct DK in the longitudinal direction. If
an arc flashover now occurs in a functional module FM, the air in
this functional module FM is supplied with a large amount of heat
causing it to expand explosively. The pressure wave produced can
then be dissipated via the valve system KS 1, 2, 3 (in FIG. 1) into
the pressure release duct DK but cannot spread to other functional
modules FM . . . owing to the non-return valve function of the
valve system KS 1, 2, 3. On the top surfaces DF 1, 2, 3 (in FIG. 3)
opposite the inlet openings EO . . . in the pressure release duct
DK, the pressure wave is scattered in more than one direction and
the maximum pressure is thus reduced. This process takes place more
than once while the pressure wave spreads in the longitudinal
direction of the pressure duct DK, with the result that the
pressure peak can be safely reduced. In addition, surfaces sloping
FS 1, 2, 3 are shown in the longitudinal direction above the inflow
openings EO . . . , provided on each individual functional module
FM, FM . . . , and on the end regions EB1, 2 of the pressure
release duct DK, and these surfaces cause the pressure wave to be
scattered further, and thus cause the pressure peaks to be reduced.
The swirling of the gases in the pressure release duct DK causes
both the pressure and the temperature to be reduced dramatically.
In order to finally dissipate the gases, the pressure release duct
DK can be connected to a chimney system KM or coupled to an
absorption element AE, with the pressure and the temperature being
reduced to such an extent that the gases can be safely dissipated
onto the area surrounding the installation. Absorption elements AE
usually comprise chambers filled with a filling material, for
example metal chips, in which the gases are heavily scattered,
swirled, cooled and neutralized. The dissipation of heat takes
place through heat conduction and possibly also melting processes
of the filling material. Instead of the loose filling material,
metal sheets which are arranged offset in relation to one another
may also be used to cool and swirl the flow, with it also being
possible for the metal sheets to have distributed openings.
Furthermore, the arrows are also indicated a possible course for
the flow of gas GS in the pressure release duct DK. In particular,
the swirling areas can be seen on the sloping surfaces FS 2, 3.
[0024] FIG. 3 shows an enlarged illustration of the pressure
release duct DK having a trapezoidal cross section as an exemplary
embodiment of the invention. In addition to trapezoidal cross
sections, for example cross sections in the form of semi-circles or
other polygonal forms may also be provided according to the
invention.
[0025] The inlet openings EO . . . having the valve systems KS can
be seen. These are, for example, loose valves on the inlet openings
EO . . . , which are opened by the pressure wave, thus allowing the
flow of gas GS into the pressure release duct DK. Some of the inlet
openings EO . . . are opposite sloping cover surfaces DF 1, 2, 3,
which reflect the incoming hot gases in different directions and
thus dissipate them so that the pressure peaks can be reduced. A
course for the flow directions SR of the gas which is possible
owing to the swirling is depicted. Also shown are the ventilation
openings LO 1, 2 which are provided on the cover surface DF 1, 2, 3
of the pressure release duct DK and are closed in a pressure-tight
manner by means of the valve system KS . . . in the event of a
pressure surge in the pressure release duct DK.
* * * * *