Electrical equipment including pressure relief devices

Abstract

An electrical device including a pressure release device is disclosed. An electrical device includes: a housing (2), an electrical device (4) located inside the housing (2), a fluid port (6), a pressure release device (8) and a detection system, the detection system being adapted to detect a fault condition associated with the electrical device (4) based on at least one indicating event. The transfer of the pressure release device (8) from a first operating position to a second operating position is adapted to occur in response to a first predetermined pressure increase inside the housing (2). The electrical device includes a fire protection system (10), the fire protection system (10) including a fire protection substance and being operably connected to the detection system, such that the fire protection system (10) is adapted to release the fire protection substance in response to a fault condition detected by the detection system.

Description

Technical Field

[0001] The present invention relates to electrical equipment comprising a pressure relief device. Background Art

[0002] A known electrical device includes: a housing; an electrical device located inside the housing; a fluid port that provides a fluid connection from the inside of the housing to the outside of the housing; and a pressure relief device having a first operating position suitable for preventing fluid from flowing through the fluid port and a second operating position suitable for allowing fluid to flow through the fluid port.

[0003] In the event of a fault in which an arc occurs in an electrical device inside the housing, the air surrounding the arc expands, causing a pressure increase inside the housing that shifts the pressure relief device from a first operating position to a second operating position, thereby allowing hot gases to flow out of the housing.

[0004] One of the problems associated with the above-mentioned known electrical devices is that the hot gas flowing out of the housing through the fluid port may include flammable gas, which does not ignite inside the housing, but may ignite outside the housing when its concentration is reduced. In addition, the hot gas may also ignite inside the housing, with the flame ejected from the fluid port. Therefore, the hot gas flowing out of the housing may cause a fire hazard in the vicinity of the fluid port. Summary of the invention

[0005] The object of the present invention is to provide an electrical device to solve the above problems. The object of the present invention is achieved by the electrical device described below.

[0006] The invention is based on the idea of ​​providing an electrical device having a fire protection system comprising a fire protection substance, wherein the fire protection system is adapted to release the fire protection substance upon detection of a fault condition associated with an electrical device located inside the housing. In an embodiment, the fault condition is simply detected based on a transfer of a pressure release device from a first operating position to a second operating position, and the transfer triggers the release of the fire protection substance.

[0007] An advantage of the electrical device of the present invention is that fire hazards caused by fault conditions can be minimized or even eliminated. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In the following, the invention will be described in more detail by means of preferred embodiments with reference to the accompanying drawings, in which:

[0009] Figure 1 An electrical device according to an embodiment of the present invention is shown;

[0010] Figure 2 Shows Figure 1Cross-sectional view of electrical equipment;

[0011] Figure 3 Shows Figure 2 an enlarged view of a portion A of the cross-sectional view; and

[0012] Figure 4 Shows Figure 1 Pressure relief devices and fire protection systems for electrical equipment. DETAILED DESCRIPTION

[0013] Figure 1 An electrical device according to an embodiment of the present invention is shown, and Figure 2 A cross-sectional view of the electrical apparatus is shown. The electrical apparatus comprises a housing 2, an electrical device 4, a fluid port 6, a pressure relief device 8, a fire protection system 10 and a detection system adapted to detect a fault condition associated with the electrical device 4 based on at least one indicating event.

[0014] exist Figure 2 The electrical device 4 schematically depicted in FIG. 1 is located inside the housing 2 and comprises an electrical converter adapted to convert electrical energy from one form to another. The electrical converter is a frequency converter. In an alternative embodiment, the electrical converter is an inverter or some other converter comprising a plurality of controllable semiconductor switches.

[0015] The housing 2 contains air, so that the electrical device 4 is partially surrounded by the air. In an alternative embodiment, the housing contains a gas other than air, and the electrical device is at least partially surrounded by the gas.

[0016] The fluid port 6 provides a fluid connection from the inside of the housing 2 to the outside of the housing 2. The fluid port 6 comprises a hole in the wall of the housing 2.

[0017] The pressure relief device 8 has a first operating position adapted to prevent fluid from flowing through the fluid port 6 and a second operating position adapted to enable fluid to flow through the fluid port 6. Figure 2 , the pressure release device 8 is in the first operating position. The transfer of the pressure release device 8 from the first operating position to the second operating position is adapted to occur in response to a first predetermined pressure increase inside the housing 2. In other words, the first predetermined pressure increase inside the housing 2 causes the pressure release device 8 to move outward relative to the housing 2.

[0018] Reference Figure 1 and Figure 2, the pressure relief device 8 defines a pressure relief device plane, and the fluid port 6 is arranged on a flat portion of the housing 2 defining a first housing plane, wherein during the transition of the pressure relief device 8 from the first operating position to the second operating position, the pressure relief device plane remains parallel to the first housing plane while the pressure relief device 8 moves outwardly relative to the housing 2. In an alternative embodiment, the pressure relief device includes a pressure relief valve and / or a pressure relief valve flap hinged to the housing from one of its edges.

[0019] The fire protection system 10 comprises a fire protection substance and is operatively connected to the detection system. The fire protection system 10 is adapted to release the fire protection substance inside the housing 2 as a response to a fault condition detected by the detection system.

[0020] In this context, releasing the fire retardant means releasing at least a portion of the total amount of fire retardant in the fire protection system. In some embodiments, the release of the fire retardant is stopped in response to the transfer of the pressure release device from the second operating position back to the first operating position.

[0021] In an embodiment, the fire retardant comprises carbon dioxide or other substances suitable for replacing oxygen. In another embodiment, the fire retardant comprises liquid nitrogen or other substances suitable for reducing temperature. In yet another embodiment, the fire retardant comprises dry water or other substances suitable for capturing explosive gases. Dry water, sometimes referred to as empty water, is a water-air emulsion (emusion) in which tiny water droplets are surrounded by a sandy silica coating.

[0022] At least one indication event comprises a transition of the pressure relief device 8 from a first operating position to a second operating position. The transition is a usable indication because it is caused by a first predetermined pressure rise inside the housing 2, which in turn is a strong indication of an arc in the electrical device 4 inside the housing 2. The transition causes the fire protection system 10 to release a fire protection substance inside the housing 2.

[0023] The first predetermined pressure increase inside the housing 2 causes the pressure relief device 8 to shift from the first operating position to the second operating position because the excess pressure creates a force acting in an outward direction on the pressure relief device 8. In addition, the first predetermined pressure increase inside the housing 2 inherently creates a fluid flow from the inside of the housing 2 through the fluid port 6 to the outside of the housing 2. This fluid flow carries the fire retardant substance out of the housing.

[0024] The first predetermined pressure rise inside the housing 2 is selected so that it is greater than any pressure rise that occurs inside the housing 2 during transportation, installation and normal use of the electrical device. In an embodiment, the first predetermined pressure rise inside the housing is defined by the difference between the pressure inside the housing and the pressure outside the housing. In another embodiment, the criterion for the presence of the first predetermined pressure rise inside the housing includes a condition for the rate of rise of the pressure inside the housing.

[0025] Reference Figure 3 , the pressure release device 8 is supported to the housing 2 by a support structure 12, which includes a leaf spring 124 fastened to the pressure release device 8 by a screw 126. The leaf spring 124 is in contact with the inner surface of the housing 2 and is suitable for returning the pressure release device 8 to the first operating position if the pressure release device 8 deviates from the first operating position in the direction of the second operating position.

[0026] The fire protection system 10 includes a disposable cartridge containing a fire retardant. The disposable structure is used because in practice, an arc occurring in a frequency converter can destroy the frequency converter. In an alternative embodiment, the fire protection system includes a reusable container provided with a valve operably connected to a detection system. The valve is suitable for releasing a necessary amount of fire retardant and leaving the remaining fire retardant in the reusable container for later use. In another alternative embodiment, the fire protection system includes a plurality of disposable cartridges comprising different fire retardants.

[0027] Figure 4 Shown is a pressure relief device 8 and a fire protection system 10 fastened to the pressure relief device 8. The screw 126 and the leaf spring 124 have been detached from the pressure relief device 8.

[0028] Reference Figure 4 , the fire protection system 10 is fastened to the pressure relief device 8 by a fastening system, which includes four fastening screws 94. By unscrewing the four fastening screws 94, the fire protection system 10 can be separated from the pressure relief device 8.

[0029] The detection system comprises two detection protrusions 102 attached to the fire protection system 10. During the transition of the pressure relief device 8 from the first operating position to the second operating position, the detection protrusions 102 are adapted to contact with the edge of the fluid port 6, so that the detection protrusions 102 bend. The detection system is adapted to detect a fault condition based on the bending of the detection protrusions 102. In an alternative embodiment, the detection system comprises at least one detection protrusion, and the detection system is adapted to detect a fault condition based on a deformation of the at least one detection protrusion, such as a bending or breaking of the at least one detection protrusion.

[0030] The bending of the detection protrusions 102 triggers the release of the fire retardant substance from the fire protection system 10 and creates a flow aperture near each detection protrusion 102. Each flow aperture is located between the bent detection protrusion 102 and the pressure release device 8 and is adapted to provide a path for the fire retardant substance to leave the fire protection system 10.

[0031] The release of the fire retardant substance from the fire retardant system 10 is triggered by the bending of the detection protrusion 102, because the wall of the container containing the fire retardant substance is broken by the deformation of the detection protrusion 102. In an alternative embodiment, the deformation of at least one detection protrusion releases the fire retardant substance by pulling out a pin from the container containing the fire retardant substance.

[0032] In another alternative embodiment, the detection system includes a mechanical connection between the pressure release device and the fire protection system, so that the transfer of the pressure release device from the first operating position to the second operating position releases the fire protection substance from the fire protection system. The mechanical connection between the pressure release device and the fire protection system includes a cable and / or a linkage.

[0033] In yet another alternative embodiment, the detection system comprises at least one sensor adapted to detect at least one indication event, the at least one sensor comprising at least one of the following: a pressure sensor, a temperature sensor, a photoelectric sensor, a strain gauge. The pressure sensor is adapted to detect a second predetermined pressure rise inside the housing, wherein at least one indication event comprises the second predetermined pressure rise. The temperature sensor is adapted to detect a predetermined temperature rise inside the housing, wherein at least one indication event comprises the predetermined temperature rise. The photoelectric sensor is adapted to detect a predetermined illuminance rise inside the housing, wherein at least one indication event comprises the predetermined illuminance rise. The predetermined illuminance rise is selected such that the photoelectric sensor is adapted to detect an arc inside the housing, but is adapted to ignore all normally occurring illuminance changes inside the housing. The strain gauge is adapted to detect a predetermined deformation in the support structure, such as a predetermined deformation in a leaf spring, wherein at least one indication event comprises the predetermined deformation.

[0034] In an embodiment where at least one indication event includes a second predetermined pressure increase, the second predetermined pressure increase is less than the first predetermined pressure increase. Therefore, the fire protection system begins to release the fire protection substance inside the housing before the pressure relief device is opened, thereby ensuring that the fire protection substance flows out of the housing at the moment the pressure relief device is opened, and reducing the risk of fire in the vicinity of the fluid port.

[0035] In an embodiment where the detection system comprises at least one sensor, the electrical device comprises a control system communicatively connected to the at least one sensor and adapted to trigger release of the fire protection substance from the fire protection system in response to at least one indicating event detected by the at least one sensor.

[0036] It is obvious to a person skilled in the art that the inventive concept can be implemented in various ways.The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

1. An electrical device comprising: Housing (2); An electrical device (4) located inside the housing (2); a fluid port (6) providing a fluid connection from the interior of the housing (2) to the exterior of the housing (2); a pressure relief device (8) having a first operating position adapted to prevent fluid from flowing through the fluid port (6) and a second operating position adapted to enable fluid to flow through the fluid port (6), wherein the transition of the pressure relief device (8) from the first operating position to the second operating position is adapted to occur in response to a first predetermined pressure increase inside the housing (2); and a detection system adapted to detect a fault condition associated with the electrical device (4) based on at least one indicating event; It is characterized in that The electrical device comprises a fire protection system (10), the fire protection system (10) comprising a fire protection substance and being operatively connected to the detection system such that the fire protection system (10) is adapted to release the fire protection substance in response to a fault condition detected by the detection system; The pressure relief device (8) defines a pressure relief device plane, and the fluid port (6) is arranged on a flat portion of the housing (2) defining a first housing plane, wherein during the transition of the pressure relief device (8) from the first operating position to the second operating position, the pressure relief device plane remains parallel to the first housing plane; The detection system comprises a mechanical connection between the pressure release device (8) and the fire protection system (10) such that the transfer of the pressure release device (8) from the first operating position to the second operating position releases the fire protection substance from the fire protection system (10); and The housing (2) contains air so that the electrical device (4) is at least partially surrounded by the air; Therein, the at least one indication event comprises a transfer of the pressure release device (8) from the first operating position to the second operating position.

2. The electrical device according to claim 1, characterized in that The detection system further comprises at least one sensor adapted to detect the at least one indicator event.

3. The electrical device according to claim 2, characterized in that: The at least one sensor comprises at least one of the following: a pressure sensor, the pressure sensor being adapted to detect a second predetermined pressure increase inside the shell (2), wherein the at least one indication event comprises the second predetermined pressure increase; a temperature sensor, the temperature sensor being adapted to detect a predetermined temperature increase inside the shell (2), wherein the at least one indication event comprises the predetermined temperature increase; a photoelectric sensor, the photoelectric sensor being adapted to detect a predetermined illuminance increase inside the shell (2), wherein the at least one indication event comprises the predetermined illuminance increase.

4. The electrical device according to claim 2, characterized in that: The pressure relief device (8) is supported to the housing (2) by a support structure (12), and the at least one sensor comprises a strain gauge adapted to detect a predetermined deformation in the support structure (12), wherein the at least one indication event comprises the predetermined deformation.

5. The electrical device according to claim 1, characterized in that: The fault conditions that the detection system is adapted to detect include arcing inside the housing (2).

6. The electrical device according to claim 1, characterized in that: The fire protection system (10) comprises a disposable cartridge containing the fire protection substance.

7. The electrical device according to claim 1, characterized in that: The fireproofing substance comprises at least one of the following: a substance suitable for replacing oxygen, a substance suitable for reducing temperature, and a substance suitable for capturing explosive gas.

8. The electrical device according to claim 1, characterized in that The electrical device (4) comprises an electrical converter adapted to convert electrical energy from one form to another.

9. The electrical device according to claim 1, characterized in that: The fire protection system (10) is adapted to release the fire protection substance inside the housing (2) in response to a fault condition detected by the detection system.

10. The electrical device according to claim 1, characterized in that The mechanical connection between the pressure release device (8) and the fire protection system (10) comprises cables and / or connecting rods.

11. The electrical device according to claim 1, characterized in that: The detection system comprises at least one detection protrusion (102) attached to the fire protection system (10), and the detection system is adapted to detect the fault condition based on deformation of the at least one detection protrusion (102).

12. The electrical device according to claim 11, characterized in that The deformation of the at least one detection protrusion (102) includes bending or breaking of the at least one detection protrusion (102).

13. The electrical device according to claim 11, characterized in that The deformation of the at least one detection protrusion (102) includes bending of the at least one detection protrusion (102), which triggers the release of the fire protection substance from the fire protection system (10) and creates a flow hole near each of the at least one detection protrusion (102).

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