EP2433676B1 - Fire-resistant housing for a frequency converter - Google Patents

Description

Technical area

The present invention relates to a fire-resistant housing for a power converter, in particular for a power converter of a rail vehicle, wherein the housing is made of a metallic material, with a heat insulating member made of a non-flammable material, which is arranged on a housing part of the housing on an outer wall surface in a fire in the interior to reduce the heat flow in an adjacent outdoor space.

State of the art

It is known that power electronic components of a power converter are usually housed in a metal housing, which forms a shield for electromagnetic radiation in addition to the mechanical protection. The metal structure is a good conductor of heat for the internal power dissipation.

This good thermal conductivity is disadvantageous when it comes to keeping an escape route bypassing the outside as long as possible passable in the event of a fire in the interior of the converter housing. In the case of rail vehicles, for safety reasons, it is increasingly required that, in the event of a power converter fire, the metal structure facing the outer space experience only a limited increase in temperature. Depending on the risk class of the rail vehicle, these are Requirements different. For vehicles driving through a tunnel, the requirements are higher than for trams. In Germany, the German industry standard DIN 5510 specifies which limit values apply. For a rail vehicle, for example, be required that a housing for high-performance components in the interior must be designed so that over 30 minutes no gaps or openings or sustained flames can arise on the outside of the housing. This measure protects the escape corridor, but also prevents the spread of fire during the evacuation phase.

As is known, the space conditions on a rail vehicle, e.g. in the power train of an electric locomotive, narrowly bounded. However, the heat development in the interior of a railway power converter can be considerable, so that for safety reasons increasingly higher demands are placed on the fire resistance of the converter housing. This applies not only to power converters which are arranged in the interior of a rail vehicle, but also to those in underfloor mounting, in which the heating of an overlying escape route delays as long as possible and fire spreading should be prevented.

From the EP 1 882 496 A1 Fire protection is known in which a protective wall with an intumeszenzfähigen, that is thermally expansible sheet is coated. In case of fire, the sheet swells up. The expansion can be several hundred percent and forms a barrier to heat flow. In the case of a power converter, however, the temperatures occurring in the interior in the event of fire can be so great that an intumescent coating alone is insufficient to keep an adjacent escape route passable.

In the course of ever-increasing safety awareness, the fire safety regulations are tightened. It not only reduces the permissible surface temperature of the converter housing, but the standard also stipulates the durability of the protective measure in a rail vehicle, which must remain functional for more than 20 years (German industrial standard DIN 50 155). On the part of the operator of a rail vehicle, there is also the desire that the protective measures over a long period of operation does not require extensive maintenance.

Presentation of the invention

It is an object of the present invention to provide a fire-resistant housing for a power converter, which better isolates the heat flow through a housing part in an adjacent safety-critical outside space in the event of a fire inside the housing and in which this foreclosure effect remains as maintenance-free as possible over a long operating period ,

This object is achieved by a fire-resistant power converter with the features of claim 1. Advantageous embodiments of the invention are defined in the dependent claims.

According to the invention the object is achieved in that a heat insulating part is provided, which is connected both by material bond as well as by positive engagement with the housing part, which borders on a safety-critical exterior space. In other words, according to the invention, therefore, the heat insulating member is mounted on its support in two ways: on the one hand it is glued to it, on the other it is held by refractory holding means on the carrier. The housing part may be a door or lid part or a side part, but also consist of several housing parts. Due to the non-positive adhesive connection is achieved that during the normal operating time, that is, without fire, the heat insulating part adheres to its carrier surface. As a result, shock loads that act during the entire operating time of the rail vehicle can be absorbed by a large area. The mechanical holding means come thereby in normal operation less strong, so that they can be made weaker. In case of shocks areas of the heat insulation part in the field of mechanical brackets are less stressed. This is beneficial for the life of the connection. In the case of fire, however, where the adhesive bond can dissolve due to the effect of heat, the refractory holding means ensure that the heat insulating part rests flat on the housing part, when the carrier begins to deform due to the action of heat. This increases the stability of the thermal insulation. As a result, the function of the heat-tracing retarding measure remains effective over a long period of time. The burning interior is thermally better sealed off from an adjacent exterior space. Due to the better foreclosed temperature is an escape route, which leads past a converter in a machine room of a rail service vehicle, in case of emergency for the escaping driver more safely passable. The escape route is not blocked by protruding parts of the thermal insulation. The attached to the outer wall surface heat insulation also has the advantage that for maintenance purposes, a check from the outside by visual control is easily possible without a lid part must be opened. The attachment of the heat insulating member to the outer wall of the housing by mechanical fasteners is robust and virtually maintenance free over a long period of operation. The mounting on the outside of the housing has the further advantage that the interior of the converter housing, which is usually a clean room, is not contaminated by peeling parts of the insulating material. In principle, all insulation materials are suitable for the heat insulation part, which are suitable for forming a sufficiently large barrier in the event of fire for the heat flow coming from the interior.

It is particularly advantageous if the outer wall surface of the housing part is provided over its entire surface with a layer of adhesive. As a result, the vibrations occurring during operation of the rail vehicle are essentially absorbed by the adhesive layer and mechanical overstressing of the heat insulation part is avoided. This increases the service life of the thermal insulation.

In a preferred embodiment it is provided that the positive connection is formed by a plurality of connectors, wherein each of these connectors is connected at one end to the housing part and is guided at another end through a through hole in the heat insulating member, wherein the inserted end by means of a holding part engages behind the heat insulating part. In case of fire, the escape corridor is passable unhindered and not blocked by protruding heat insulation parts.

Cost effective while the connector can be designed as a bolt, or as retaining tabs that are bent or caulked at its plugged end. The connector may also consist of an insulator. The holding part may be formed for example by a disc, or a perforated plate, a grid, a steel mesh, an expanded metal mesh, or another sheet with recesses.

Preferably, the heat insulating part of a web of a mineral material, for example a mineral or a rock wool, which is laminated, for example, with an aluminum layer. The low weight of this mineral webs is particularly advantageous in a rail vehicle.

Alternatively, another embodiment may also be such that the heat-insulating member is provided by a commercially available cement-based fire protection panel, e.g. is formed from calcium silicate or from a gypsum and / or mineral fiber board.

A particularly good thermal insulation is achieved when the heat insulating part extends beyond the frame of the converter housing, in other words when viewed in the direction of the interior of the cabinet body, the heat insulating part is larger, so this overlaps in the edge region. This ensures that the radiated heat from the metal frame is kept away from the passing escape route and a fire spread is delayed.

A very particularly preferred embodiment may be characterized in that the housing part is coated on a inner wall surface lying to the interior with a known intumeszenzfähigen coating. This intumescent coating foams in case of fire, creating an additional thermal barrier. In case of fire, the metal structure heats up later. Although this effect is only of comparatively short duration, the useful life of the escape route is extended. Such an intumescent coating may be, for example, an expandable graphite-containing formulation.

In order to curb the escape of hot gases from the interior of the converter housing in case of fire, may be provided in a preferred embodiment, that in the gap formed by the inner wall surface of the housing part and the opposite end face of the frame, either on one and / or the other of these Surfaces an intumeszenzfähige coating or an intumeszenzfähiges sealing tape is attached. This can be so for example take place that the applied on the inner wall surface of the housing part intumeszenzfähige coating is drawn into the gap.

It is advantageous if this intumeszenzfähige coating is provided with a reinforcement, such as metal fibers, glass fabric or strands of carbon fibers or the like.

This may in turn be advantageous if this reinforcement extends into the gap between the cover part and the frame part, since in the event of fire, the sealing effect is thereby improved.

A further improvement of the space closure can be achieved by also the end face of the frame, which points to the housing part, is also coated with an intumeszenzfähigen coating. By the coating is formed on both cleavage surfaces, the escape of hot flue gases is particularly effectively insulated in case of fire.

In a particularly preferred embodiment of the invention, the interior of the cabinet body is divided by means of abrasion-free insulation panels in individual subspaces. Since these sub-areas pose a lower risk potential, the fire protection requirements are reduced. As a result, a cover part which covers these subspaces toward the escape corridor can be formed with a thinner insulation.

A thickness of the insulating part of about 0.5 cm to 3 cm is preferred.

It may also be advantageous if the refractory connection part is made of an insulator. As a result, the heat flow through the holding means is prevented in the event of fire. For example, a ceramic, glass or porcelain part.

Brief description of the drawing

Figur 1

ein Bahnfahrzeug in einer Draufsicht, bei dem in einem an den Führerstand angrenzenden Raum zwei Stromrichter angeordnet sind, zwischen denen sich eine Fluchtkorridor befindet;

Figur 2

einen Stromrichter in einem Schienenfahrzeug, von dem ein Gehäuseteil ebenfalls an einen vorbeiführenden Fluchtweg grenzt, wobei gemäß einer besonderen Ausgestaltung der Erfindung, der Innenraum des Stromrichtergehäuses mittels Isolationsplatten in Teilräumen geteilt ist;

Figur 3

eine Detaildarstellung des Gehäuseteils des Stromrichtergehäuses, welches die erfindungsgemäße Befestigung des Wärmeisolationsteils zeigt;

Figur 4

eine Detaildarstellung des Gehäuse-Deckelteils im Bereich des Rahmens des Stromrichtergehäuses, wobei die Dichtung im Spalt zwischen dem Deckelteil und dem Rahmen dargestellt ist.

To further explain the invention, reference is made in the following part of the description to the drawings from which further advantageous embodiments, details and developments of the invention with reference to an illustrated, non-limiting embodiment can be found. It shows:

FIG. 1

a railway vehicle in a plan view, in which two power converters are arranged in a space adjacent to the driver's cab, between which there is an escape corridor;

FIG. 2

a power converter in a rail vehicle, of which a housing part also adjacent to a passing escape route, wherein according to a particular embodiment of the invention, the interior of the power converter housing is divided by means of insulating plates in subspaces;

FIG. 3

a detailed view of the housing part of the converter housing, showing the attachment of the heat insulating part according to the invention;

FIG. 4

a detailed view of the housing cover part in the region of the frame of the converter housing, wherein the seal is shown in the gap between the cover part and the frame.

Embodiment of the invention

The FIG. 1 shows in a view from above the arrangement of two power converters in the vehicle head of a railway vehicle 14. Between the two housings 1 a path passes, which forms an access to the driver's cab 15. In an emergency, for example in the event of a fire, this route is also the escape route for persons in the driver's cab. In the event of a fire in the interior of a converter housing 1, the effect of heat on persons passing the escape route 13 must be kept so low, at least over a period of time, that they can use the corridor without prejudice to reach the passenger area 16.

The two power converters 1 are located in a space that is limited both to the driver's cab 15 and to the passenger area 16, in each case by a wall 17, 18 with doors that satisfy the room closure or thermal insulation criterion "EI15".

As already mentioned, the escape corridor 13 must be passable as long as possible in case of fire. This is achieved by at least the adjacent to the outer space 13 housing parts 12 - in the present case, this is a cover part on the converter housing - are provided with a heat insulation according to the invention.

The FIG. 2 shows in a three-dimensional representation of a statically self-supporting cuboid power converter housing 1, which is arranged in a wagon of a rail vehicle 14. Here too, a housing part 12 - a cover part of the housing body - adjoins a safety-critical escape route 13. This escape route 13 should, in the event that it in the interior 11 of the converter housing 1 comes to a fire, as long as possible passable for passengers from the passenger compartment 16, without these people come to harm due to the radiated heat from the housing part 12. In the presentation of the FIG. 2 is indicated by broken lines that the interior 11 of the power converter by means of insulation plates 27 into individual subspaces 11 'split. This ensures that the fire protection requirements are lower due to the smaller volume, so that the insulation of the housing cover 12 may be formed correspondingly thinner.

The FIG. 3 An adhesive layer 2 forms an adhesive connection 20 on the one hand with the metal wall 12 and on the other hand with the insulating part 4. In addition to this cohesive connection 20, the heat insulating part 4 by means of several on the outer wall surface 22 arranged distributed fasteners 6 each attached by positive locking 21. This positive connection 21 is fireproof, that is, it is designed so that it also in case of fire, when the adhesive bond 20 dissolves due to the action of heat from the interior 11 of the converter housing 1, the heat insulating member 4 into contact with the outer wall surface 22 of the housing part 12 stops. In the present example, it consists in each case of a metallic bolt, which is welded with its one end 9 to the housing part 12 and the other end 8 is inserted through a through hole 7 in the heat insulating part 4 therethrough. This inserted end 8 is threaded. By means of a disc 5 made of metal and a threaded nut 6, the heat insulating part 4 is held even in case of fire on the housing part 12 fitting, so that too in a large heat, the insulation effect is not affected by a detachment of the heat insulating part 4 of the housing wall 12.

In the illustrated embodiment, the heat insulating part 4 is a cement-based fire protection board, which is held by means of the connector 3 in case of fire in contact with the outer wall surface 22. However, the heat insulation part 4 may also be formed of another insulating material, such as a mineral web, a mineral or a rock wool, which is laminated, for example, with an aluminum layer. In such an embodiment, it makes sense to form the holding part 5 flat, for example as a metal plate with recesses, or as wire mesh, mesh, expanded metal mesh, perforated plate, or the like.

Of course, the releasable screw-nut connection shown in the present embodiment may also be a non-detachable connection, for example by a holding part is snapped onto the connectors 3 by means of a snap connection.

The FIG. 4 shows in a sectional detail representation of a particularly preferred embodiment of the invention. Shown in a section of the conclusion of the body edge. The heat insulation part 4 is - as already shown above - attached by means of an adhesive bond 20 and a screw-nut connection 3.6 to the housing part 12. At the edge of the housing part 12 is bent in the form of a "U". The housing part 12 extends over the end face 27 of the frame 19. An intumescent coating 24 is attached to the surface 23 lying to the interior 11. This coating 24 also extends in the gap 25 formed between the surfaces 23 and 27. It is provided with a reinforcement 10. In the event of a fire, the volume of the coating 24 increases due to the effect of heat from the interior space 11. As a result, the gap 25 is closed by the intumescent material 24, at least at the beginning of the fire. Hot flue gases are prevented from entering the exterior space 13.

In the event of non-firing, the rubber seal 26 hermetically closes off the inner space 11, as a result of which the intumescent-capable coating 24 is also protected from the outside from the action of moisture.

In the drawing of the FIG. 4 is also on the end face 27 in addition to see in the gap 25 intumeszenzfähige coating 28, which in case of fire, the described sealing effect is further improved.

In practice it has been found that in a power converter housing as is typically used for railway vehicles, a thickness 29 of the heat insulating part 4 in the range between 0.5 cm and 3 cm is favorable.

List of Used Reference Numbers

1

casing

2

adhesive

3

Interconnects

4

Heat insulation part

5

retaining washer

6

fastener

7

Through Hole

8th

the plugged end of the connector. 3

9

the attached to the housing part end of the connector

10

reinforcement

11

inner space

11 '

subspace

12

Housing part, cover part

13

Outdoor space, escape corridor

14

track vehicle

15

cab

16

passenger region

17

wall

18

wall

19

frame part

20

cohesive connection

21

positive-locking connection

22

Outer wall surface of the housing part 12th

23

Inner wall surface of the housing part 12th

24

intumescent coating

25

gap

26

poetry

27

insulation plate

28

coating

29

Thickness of the heat insulating part 4

Claims (12)

1. Fire-resistant housing for a frequency converter, in particular for a frequency converter of a rail vehicle, wherein the housing (1) is manufactured from a metallic material, comprising:

   - a heat insulation part (4) made of a non-flammable material which is arranged on a housing part (12) of the housing (1) on an outer wall surface (22), in order, in the event of a fire in the interior space (11), to attenuate the heat flow into an adjacent exterior space (13), wherein

   - the heat insulation part (4) is connected to the housing part (12) by means of a substance-to-substance bond (20) and a fire-resistant, form-fit connection (21),

   characterised in that
   the substance-to-substance bond (20) is formed by an adhesive layer (2) embodied over the whole surface between the outer wall surface (22) and the surface of the heat insulation part (4) facing the housing part (12).
2. Housing according to claim 1,
   characterised in that
   the form-fit connection (21) is formed by a plurality of connectors (3), wherein each connector (3) is connected by one end (9) to the housing part (12) and by another end (8) is inserted through a through-hole (7) in the heat insulation part (4), wherein the inserted end (8) engages behind the heat insulation part (4) by means of a retaining part (5).
3. Housing according to one of claims 1 or 2, characterised in that
   the heat insulation part (4) is formed from a mineral material, preferably from a mineral wool or rock wool laminated with a metallic layer.
4. Housing according to one of claims 1 or 2,
   characterised in that
   the heat insulation part (4) is a fire protection plate, particularly preferably made of calcium silicate.
5. Housing according to claim 3 or 4,
   characterised in that
   viewed in the line of vision towards the housing part (12) from the exterior space (13) in the direction of the interior space (11) of the housing body, the heat insulation part (4) covers the frame (19) of the body at least completely.
6. Housing according to one of claims 1 to 5,
   characterised in that
   the housing part (12) is coated on an inner wall surface (23) facing the interior space (11) with an intumescent coating (24).
7. Housing according to claim 6,
   characterised in that
   the intumescent coating (24) protrudes into a gap (25) which is formed by the inner wall surface (23) and the adjacent end face (27) of the frame (19) of the housing (1).
8. Housing according to claim 7,
   characterised in that
   the intumescent coating (24) is provided with a reinforcement (10) which extends into the gap (25).
9. Housing according to claim 7,
   characterised in that
   the end face (27) is provided with a coating (28), running around the gap (25), of an intumescent material.
10. Housing according to one of the preceding claims,
    characterised in that
    the interior space (11) is divided by means of insulation plates (27) into partial spaces (11').
11. Housing according to claim 10,
    characterised in that
    the housing part (12) is a lid part, which covers the partial spaces (11') of the housing (1) as far as the exterior space (13).
12. Housing according to one of the preceding claims,
    characterised in that
    the heat insulation part (4) has a thickness (29) of 0.5 cm to 4 cm.

Images