Search

EP-4739966-A1 - FURNACE POWER SUPPLY APPARATUS WITH A COOLING SYSTEM

EP4739966A1EP 4739966 A1EP4739966 A1EP 4739966A1EP-4739966-A1

Abstract

The invention relates to a furnace power supply apparatus (20) for the supply of an electric furnace with electric energy, wherein the furnace power supply apparatus (20) is connectable to a three-phase power network (10) and at least one electrode (30) of the electric furnace, wherein the furnace power supply apparatus (20) comprises at least one power module (100), wherein the power module (100) comprises a rectifier stage (110), connectable to a three-phase power network (10), and a converter stage (120), connectable to at least one electrode (30) of the electric furnace, wherein the furnace power supply apparatus (20) comprises at least one DC bus (130), wherein the DC bus (130) connects the rectifier stage (110) to the converter stage (120) of the at least one power module (100), wherein the furnace power supply apparatus (20) comprises a cooling system (140).

Inventors

  • NERI, LUCA
  • PASCH, THOMAS

Assignees

  • SMS group S.p.A.

Dates

Publication Date
20260513
Application Date
20240923

Claims (16)

  1. 1. Furnace power supply apparatus (20) for the supply of an electric furnace with electric energy, wherein the furnace power supply apparatus (20) is connectable to a three-phase power network (10) and at least one electrode (30) of the electric furnace; wherein the furnace power supply apparatus (20) comprises at least one power module (100) , wherein the power module (100) comprises: a rectifier stage (110) , connectable to a three-phase power network (10) , and a converter stage (120) , connectable to at least one electrode (30) of the electric furnace; wherein the furnace power supply apparatus (20) comprises at least one DC bus (130) , wherein the DC bus (130) connects the rectifier stage (110) to the converter stage (120) of the at least one power module (100) , wherein the furnace power supply apparatus (20) is characterized in that the furnace power supply apparatus (20) comprises a cooling system (140) .
  2. 2. Furnace power supply apparatus (20) according to claim 1, characterized in that the cooling system (140) comprises a first cooling circuit (150) configured to guide a cooling fluid to and away from the power module (100) .
  3. 3. Furnace power supply apparatus (20) according to claim 2, characterized in that the cooling system (140) comprises a first cooling fluid pump (153) configured to transport the cooling fluid through the first cooling circuit (150) .
  4. 4. Furnace power supply apparatus (20) according to one of the claims 2 to 3, characterized in that cooling system (140) com- prises a filtration system (154) , preferably a de-ionizing system, configured to regulate and/or control the electrical conductivity of the cooling fluid.
  5. 5. Furnace power supply apparatus (20) according to one of the preceding claims, characterized in that the cooling system (140) comprises at least one air conditioning system (180) .
  6. 6. Furnace power supply apparatus (20) according to one of the preceding claims, characterized in that the cooling system (140) comprises a temperature and humidity control unit configured to regulate and/or control the temperature of the power module (100) and/or the humidity of a power module housing volume (102) .
  7. 7. Furnace power supply apparatus (20) according to one of the preceding claims, characterized in that the furnace power supply apparatus (20) comprises a power module housing (101) , wherein the power module housing limits a power module housing volume (102) at least partially and the power module (100) is arranged in the power module housing volume (102) .
  8. 8. Furnace power supply apparatus (20) according to claim 7, characterized in that the power module housing (101) limits the amount of emissions from electromagnetic fields.
  9. 9. Furnace power supply apparatus (20) according to one of the preceding claims, characterized in that the furnace power supply apparatus (20) comprises at least one three-phase transformer, wherein the three-phase transformer comprises a primary circuit per phase and one or more secondary circuits per phase.
  10. 10. Furnace power supply apparatus (20) according to one of the preceding claims, characterized in that the furnace power supply apparatus (20) comprises a disconnector, wherein the disconnector is arranged between the converter stage (120) and the electric furnace.
  11. 11. Furnace power supply apparatus (20) according to one of the preceding claims, characterized in that: the rectifier stage (110) of a power module (100) comprises at least one three-phase rectifier circuit, and at least one three-phase rectifier circuit per power module (100) is connected to the DC bus (130) .
  12. 12. Furnace power supply apparatus (20) according to one of the preceding claims, characterized in that the furnace power supply apparatus (20) comprises a plurality of power modules (100) connected in parallel to each other.
  13. 13. Furnace power supply apparatus (20) according to one of the preceding claims, characterized in that the furnace power supply apparatus (20) comprises at least two power modules (100) , and wherein the converter stages (120) of each power module (100) comprise at least two single-phase inverters, wherein each single-phase inverter is configured to power a different phase of the electric furnace, and wherein the single-phase inverters configured to power the same phase of the electric furnace are connected to the same DC-bus (130) .
  14. 14. Furnace power supply apparatus (20) according to claim 13, characterized in that: the furnace power supply apparatus (20) comprises at least two DC-busses () , wherein the single-phase inverters configured to power a first phase of the electric furnace are connected to a first DC-bus (130) , and wherein the single-phase inverters configured to power a second phase of the electric furnace are connected to a second DC-bus (130) .
  15. 15. Electric furnace comprising at least one furnace power supply apparatus (20) according to one the preceding claims.
  16. 16. Production line for processing metal workpieces comprising at least one furnace power supply apparatus (20) according to one of the claims 1 to 14 and at least one metal workpiece processing apparatus.

Description

Furnace power supply apparatus with a cooling system The present invention relates to a furnace power supply apparatus with a cooling system, a furnace and a production line . Metals , especially steel , and metal ores , are regularly melted and heated by an electric arc in an electric furnace . These electric furnaces , in particular an electric arc furnace , an electric reduction furnace , a submerged arc-resistance furnace , a ladle furnace or an open bath furnace , are operated with direct current ( DC ) , alternating current (AC ) or multiphase alternating current . Usually, at least one electrode is used for this purpose , which proj ects through the furnace roof into the furnace vessel , while the other electrodes are provided corresponding to the first electrode or are arranged in the bottom of the melting vessel . Electric furnaces are typically operated with dedicated power supply systems in order to both supply the required amount of electrical energy as well as to mitigate the highly nonlinear loads during operation of an electric arc furnace on the electrical power network . These power supply systems therefore produce a high amount of heat losses during operation of the electric furnace which results in increased cooling requirements . The invention is based on the problem to provide a furnace power supply apparatus with an improved cooling capability . The problem underlying the invention is solved by an apparatus according to claim 1 . Advantageous embodiments are described in the dependent tasks . In particular, the problem underlying the invention is solved by a furnace power supply apparatus for the supply of an electric furnace with electric energy, wherein the furnace power supply apparatus is connectable to a three-phase power network and at least one electrode of the electric furnace , wherein the furnace power supply apparatus comprises at least one power module , wherein the power module comprises a recti fier stage , connectable to a three-phase power network, and a converter stage , connectable to at least one electrode of the electric furnace , wherein the furnace power supply apparatus comprises at least one DC-bus , wherein the DC-bus connects the recti fier stage to the converter stage of the at least one power module , wherein the furnace power supply apparatus comprises a cooling system . In the following the term " intended use of the furnace power supply apparatus" is used to describe the furnace power supply apparatus being used to supply electric energy to an electric furnace during operation of the electric furnace . A furnace power supply apparatus designed in such a way has the advantage of an improved cooling capability . In the intended use of the furnace power supply apparatus , the furnace power supply apparatus produces a high amount of heat losses . The cooling system of the furnace power supply apparatus is able to dissipate the heat losses with an increased ef ficiency . A three-phase power network is a polyphase system used for electricity generation, transmission and distribution . A three-phase power network provides alternating current (AC ) , particularly three alternating currents , wherein each alternating current has a + 120 degree phase di f ference to one of the two other alternating currents and a - 120 degree phase di f ference to the respective other alternating current . The three-phase power network may be a high-voltage three-phase power network or a medium- voltage three-phase power network or a low-voltage three-phase power network . High-voltage can be greater than or equal to 36 kV, pre ferably greater than or equal to 60 kV, and particularly preferably greater than or equal to 100 kV . Further advantageously, high-voltage can be greater than or equal to 150 kV, preferably greater than or equal to 200 kV, and particularly preferably greater than or equal to 300 kV . Further advantageously, high-voltage can be greater than or equal to 400 kV, preferably greater than or equal to 700 kV, and particularly preferably greater than or equal to 1100 kV . Medium- voltage can be less than or equal to 36 kV . Further advantageously, medium- voltage can be less than or equal to 30 kV, preferably less than or equal to 20 kV, and particularly preferably less than or equal to 15 kV . Medium- voltage can be greater than or equal to 1 kV, preferably greater than or equal to 2 kV, and particularly preferably greater than or equal to 10 kV . Further advantageously, medium-voltage can be greater than or equal to 15 kV, preferably greater than or equal to 20 kV, and particularly preferably greater than or equal to 30 kV . Low-voltage can be greater than or equal to 50 V, preferably greater than or equal to 60 V, and particularly preferably greater than or equal to 100 V . Further advantageously, low voltage can be greater than or equal to 120 V, preferably greater than or equal to 220 V, and particularly preferably greater than or equal to 240 V . Low-vol