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EP-4310867-B1 - LOAD BANK

EP4310867B1EP 4310867 B1EP4310867 B1EP 4310867B1EP-4310867-B1

Inventors

  • Pastoor, Wolfgang

Dates

Publication Date
20260513
Application Date
20230517

Claims (7)

  1. Load bank (1) comprising a carrier frame (12) and a plurality of load bank resistor modules (9) fastened to the carrier frame (12), wherein - each load bank resistor module (9) comprises an electrically non-conductive carrier plate (10) and a plurality of heating resistors embodied as tubular heating elements (11), - the tubular heating elements (11) each have two contact points (19), a heat dissipation tube (20) and a heating wire arranged in the heat dissipation tube (20), which heating wire is electrically insulated from the heat dissipation tube (20) by an insulation material surrounding the heating wire and is electrically connected to the contact points (19), - the heat dissipation tubes (20) each have straight tube sections (20a) and at least one bent tube section (20b), - the tubular heating elements (11) are each fastened to one of the electrically non-conductive carrier plates (10), - the carrier frame (12) has, for each load bank resistance module (9), a corresponding module aperture (23), which is dimensioned in each case such that the heat dissipation tubes (20) of a load bank resistance module (9) can be guided through the module aperture (23) and the carrier plate (10) of a load bank resistance module (9) overlaps the corresponding module aperture (23), and - the load bank resistance modules (9) are each fastened to the carrier frame (12) by virtue of the electrically non-conductive carrier plates (10) of the load bank resistance modules (9) each being fastened to the carrier frame (12), such that - the carrier frame (12), together with the carrier plates (10), separates a waste heat region (13) from a contacting region (14), - the contact points (19) are arranged in the contacting region (14), - the straight tube sections (20a) of the heat dissipation tubes (20) are arranged lying in the waste heat region (13) with respect to their longitudinal extent, - the load bank (1) comprises a heat protection plate (26), which is arranged parallel to the carrier plates (10) in the waste heat region (13) and has tube apertures (26a), through which the heat dissipation tubes (20) can be guided, and - the load bank (1) comprises electrically non-conductive guide plates (27), in particular embodied from micanite, with recesses (27a), through which the tubular heating elements (11) can be guided.
  2. Load bank (1) according to Claim 1, wherein the load bank (1) comprises a fan (7), which is suitable for generating a vertical air draft in the waste heat region (13) of the load bank (1).
  3. Load bank (1) according to one of the preceding claims, wherein the carrier plates (10) are embodied from mica, in particular from micanite.
  4. Load bank (1) according to one of the preceding claims, wherein the insulation material is magnesium oxide.
  5. Load bank (1) according to one of the preceding claims, wherein the tube heating elements (11) each have a flange (22) and can be fastened releasably to one of the carrier plates (10) by virtue of the respective tube heating element (11) being able to be introduced into at least one tube aperture of the carrier plate (10) until it butts against the flange (22) and being able to be fastened releasably in this position.
  6. Load bank (1) according to Claim 5, wherein the tube heating elements (11) can each be fastened releasably by means of at least one screwed nut.
  7. Load bank (1) according to either of Claims 5 and 6, wherein a seal, in particular a silicone seal, is provided in each case between the flanges (22) and the carrier plates (10).

Description

The present invention relates to a load bank comprising a support frame and several load bank resistance modules attached to the support frame. These types of load banks are also known as high-power resistors and typically feature heating elements in which electrical energy is converted into heat, which is then dissipated by natural or (fan-forced) convection to prevent overheating. Load banks have been around for many years and are used in a wide variety of applications, such as grounding resistors, railway resistors, braking resistors, or load banks for generator testing. From the vast collection of revelations, the document [document name] serves as an example. DE 10 2018 105 558 A1 Selected as an example is a load bank of the type described at the beginning, in which tubular heating elements are grouped into modules, mounted standing on strips and contacted from below, in particular to minimize the heat load on the contact points. CN 109 887 692 A describes a load bank with a large number of horizontally arranged, U-shaped tubular heating elements that can be individually mounted and replaced. CN 102 446 610 A describes a load bank with tubular heating elements, each comprising a stainless steel tube, a resistance wire and an insulating filling. Against this background, the present invention aims to provide a load bench with improved practical suitability, particularly with regard to Efficiency, compactness, safety, durability, reliability and ease of maintenance. This problem is solved by the load bank according to claim 1. The load bank comprises a support frame and several load bank resistance modules attached to the support frame, each load bank resistance module comprising an electrically non-conductive support plate and several tubular heating elements. The system comprises heating elements. Each tubular heating element has two contact points, a heat dissipation tube, and a heating wire arranged within the heat dissipation tube. The heating wire is electrically insulated from the heat dissipation tube by an insulating material surrounding it and is electrically connected to the contact points. The heat dissipation tubes each have straight sections and at least one curved section. The tubular heating elements are each attached to one of the electrically non-conductive support plates. The support frame has a corresponding module opening for each load bank resistance module. This opening is dimensioned such that the heat dissipation tubes of a load bank resistance module can pass through it, and the support plate of a load bank resistance module overlaps the corresponding module opening. The load bank resistance modules are attached to the support frame by means of the electrically non-conductive support plates of the load bank resistance modules. The support frame, together with the support plates, separates a heat dissipation area from a contact area. The contact points are located within the contact area. The straight pipe sections of the heat dissipation pipes are arranged horizontally in the waste heat area with respect to their longitudinal extent. Through the synergistic interplay of the features according to the invention, a load bank can be provided which has improved practical suitability in several respects. Because each support plate overlaps the corresponding module opening in the support frame in longitudinal and/or transverse extension (so that the support plates cannot be passed through the module openings), the support plates together with the support frame form A continuous, wall-like barrier separates the heat dissipation area from the contacting area. This allows the heat load emitted by the heat dissipation pipes to be focused in the heat dissipation area and, to a certain extent, shielded and kept away from the contacting area. The temperature load in the contacting area is therefore relatively low, which benefits the service life and reliability of the load bank. By grouping several tubular heating elements into a single load bank resistance module (which shares a common support plate), faulty tubular heating elements can be easily and quickly removed and replaced (module-specifically), thus improving ease of maintenance. The fact that the straight sections of the heat dissipation pipes are arranged horizontally with respect to their longitudinal extent not only facilitates the insertion and removal of the heat dissipation pipes through the corresponding module opening during module installation and removal, but also promotes efficient heat dissipation. This horizontal arrangement of the straight sections of the heat dissipation pipes, perpendicular to the airflow direction, encourages the formation of turbulent flows, thereby improving heat dissipation. The statement that the straight pipe sections of the heat dissipation pipes are arranged horizontally with respect to their longitudinal extent is to be understood in this context as meaning that the straight pipe sections a