Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B6/00—Heating by electric, magnetic or electromagnetic fields
  • H05B6/02—Induction heating
  • H05B6/06—Control, e.g. of temperature, of power
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
  • G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
  • G01K7/36—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using magnetic elements, e.g. magnets, coils
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
  • G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
  • G01K7/36—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using magnetic elements, e.g. magnets, coils
  • G01K7/38—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using magnetic elements, e.g. magnets, coils the variations of temperature influencing the magnetic permeability
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B6/00—Heating by electric, magnetic or electromagnetic fields
  • H05B6/02—Induction heating
  • H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
  • H05B6/105—Induction heating apparatus, other than furnaces, for specific applications using a susceptor
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B2213/00—Aspects relating both to resistive heating and to induction heating, covered by H05B3/00 and H05B6/00
  • H05B2213/07—Heating plates with temperature control means

Definitions

• the invention relates to a device for inductive heating of a radiator, in particular Mitteis a magnetic field generated by an induction coil, with an induction coil which is connected to a resonant circuit, and a method for determining a temperature of a radiator.
• electrically conductive materials can be heated. This is done by placing an electrically conductive material in a magnetic field generated by an induction coil.
• the magnetic field is generated by alternating current, which leads to a reversal of the magnetic field in the frequency of the alternating current.
• the alternating magnetic field induces eddy currents into the electrically conductive material. These induced alternating currents counteract the resistivity of the material, generating heat.
• the induction can take place here through non-conductive materials, which experience no heating. Only the heat radiation of the electrically conductive Material can lead to heating of the surrounding non-conductive materials.
• Induction heating can be found in many applications today. The most common industrial applications include the annealing, annealing, melting or welding of metals. But also in household technology, inductive heating can be found, for example, in induction hobs.
• Induction heaters are also used to heat fluids that flow around a radiator.
• induction heaters are suitable because with a relatively high efficiency electrical energy can be converted into heat. This is particularly advantageous, since in electric vehicles no waste heat is generated by the combustion engine and thus can not be used for heating, for example, the passenger compartment.
• the temperature of an object can be detected by temperature sensors. These may be either directly attached to the article, or attached to the article in conjunction with a thermal bridge. These temperature sensors work approximately by the principle of the temperature-dependent change in the resistance of the sensor. For this purpose, however, the sensor or the thermal bridge must be used as an additional part, whereby costs arise, and further construction space is claimed.
• optical temperature measuring devices are also known which determine a temperature without contact via optical methods. In order to be able to use optical methods, the area to be measured must be observable and, in the best case, also accessible. However, this is not possible everywhere.
• the determination of the temperature of a heated by induction heating body is also carried out by methods that exploit the temperature-dependent permeability properties of a material.
• the object of the present invention to provide a device for inductive heating of a radiator and a method for determining the temperature of a radiator, an induction heater, which or in a simple and cost-effective manner, without additional components and without requirements on the accessibility of the Radiator allows to determine the temperature of the radiator.
• the object of the present invention is achieved with respect to the device with the features according to claim 1 and with respect to the method by a Warmweg horrung with the features of claim 7 solved.
• a device for inductive heating of a radiator in particular by means of a magnetic field generated by an induction coil, with an induction coil which is connected to a resonant circuit, wherein the resonant circuit has at least a first capacitor and at least a first current source, and the coil has a specific inductance and has a resistance, and the material of the radiator has a constant at least in partial temperature ranges permeability.
• the resonant circuit is operable with alternating current.
• a magnetic field that repolves with the frequency of the alternating current forms, via which alternating currents are induced in the heating element.
• the capacitor is connected in series with the current source and the induction coil.
• the material of the radiator has a temperature-dependent electrical conductivity. Via the electrical conductivity, the resistance of the material can be calculated, since the resistance and the conductivity are inversely proportional. For the method according to the invention, it is necessary for the heating element to have a temperature-dependent resistance.
• the resonant circuit has at least one first measuring device for determining the resonant frequency of the Oscillatory circuit on and / or has a second measuring device for determining the power consumption of the resonant circuit.
• the device has at least one third measuring device for measuring the temperature-dependent resistance of the heating element, wherein the temperature of the heating element can be determined from the resistance.
• the temperature of the radiator is ultimately derived.
• the temperature of the radiator is determined.
• the inductance of the induction coil is determined via the resonant frequency of the resonant circuit and / or the resistance of the induction coil is determined via the power consumption of the resonant circuit. It is also expedient for a method if From the inductance and / or the resistance of the induction coil, the temperature of the radiator is determined.
• FIG. 1 shows a schematic structure of an induction heater
• Fig. 2 shows a detailed representation of the circuit which is connected to the induction coil which generates the magnetic field
• FIG. 3 shows a flowchart which illustrates individual method steps of an exemplary embodiment.
• Figure 1 shows the basic structure of an induction heater. Shown is the induction coil 2, which is connected to a resonant circuit 3, which is operated with AC voltage. Due to the AC voltage in the resonant circuit 3, a magnetic field 1 is generated in the induction coil 2. Due to the alternating current applied in the resonant circuit 3, the magnetic field 1 is an alternating magnetic field which changes its magnetic orientation with the frequency of the alternating current.
• a radiator 4 In the magnetic field 1, a radiator 4 is inserted, which consists of an electrically conductive material. In the radiator 4 1 eddy currents 5 are induced due to the magnetic field. Since the eddy currents 5 act against the specific resistance of the radiator 4, heat is generated in the radiator 4.
• the material from which the radiator 4 consists must have a certain specific internal resistance in order to allow effective heating of the radiator 4.
• the material 4 has a constant permeability in the temperature range relevant for the induction heating, which has the consequence that temperature measuring methods which depend on the Temperature-changing permeability can not be used as a basis
• the radiator 4 must be arranged at a distance from the induction coil 2 that it is still within the forming magnetic field. Between the radiator 4 and the induction coil 2, other elements may be arranged from electrically non-conductive materials.
• the radiator 4 may also have other external dimensions and shapes in alternative embodiments. Thus, in principle any regular or even irregular arrangement of the material of the radiator 4 is conceivable.
• FIG. 2 illustrates a detailed view of the resonant circuit 3.
• a capacitor 6 is integrated into the resonant circuit 3.
• the capacitor 6 is connected in series with the induction coil 2 and the voltage source 9.
• the induction coil 2 has an internal resistance 7 and an inductance 8. These two variables can be determined in the resonant circuit 3 shown in FIG. 2 by measuring the power consumption of the resonant circuit 3 or by measuring the resonant frequency of the resonant circuit 3.
• the inductance 8 can be determined via the measurement of the resonant frequency of the resonant circuit 3 and the internal resistance 7 via the power consumption of the resonant circuit 3.
• the internal resistance of the radiator 4. This is in an embodiment according to the invention of the temperature of the radiator 4 dependent.
• the resistance of the material is directly inversely proportional to the Linked conductivity of the material. The resistance thus corresponds to the reciprocal of the electrical conductivity.
• the induced eddy currents 5 act in turn on the magnetic field 1 of the induction coil 2 and thereby change the electrical properties of the induction coil 2,
• FIG. 3 shows a flowchart 10 for clarifying the method for
• the resonant frequency of the resonant circuit 3 is measured. This can be done for example via a frequency counter. In block 12, the power consumption of the resonant circuit 3 is then measured.
• the resistance 7 of the induction coil 2 is determined from the measured in block 12 power consumption of the resonant circuit 3.
• the temperature of the heating element is now determined from the inductance 8 and / or from the resistor 7 of the induction coil 2. This procedure is based on the fact that by changing the temperature-dependent resistance of the radiator 4, the formation of the eddy currents 5 in the radiator 4 changes. The eddy currents 5 in turn have an influence on the magnetic field 1 which, in turn, acts directly on the electrical properties of the induction coil 2.

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• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• General Physics & Mathematics (AREA)
• General Induction Heating (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=48407560

Family Applications (1)

Country Status (8)

Families Citing this family (16)

Citations (9)

Family Cites Families (4)

• 2012
  • 2012-05-10 DE DE102012207847A patent/DE102012207847A1/de not_active Withdrawn
• 2013
  • 2013-05-08 JP JP2015510819A patent/JP6218809B2/ja active Active
  • 2013-05-08 KR KR1020147034727A patent/KR20150011827A/ko not_active Application Discontinuation
  • 2013-05-08 DE DE112013002397.0T patent/DE112013002397A5/de active Pending
  • 2013-05-08 CN CN201380023681.7A patent/CN104272863A/zh active Pending
  • 2013-05-08 CA CA2870241A patent/CA2870241A1/fr not_active Abandoned
  • 2013-05-08 WO PCT/EP2013/059640 patent/WO2013167686A2/fr active Application Filing
  • 2013-05-08 EP EP13721750.1A patent/EP2848088A2/fr not_active Ceased
• 2014
  • 2014-11-07 US US14/536,081 patent/US9615407B2/en active Active

Patent Citations (9)

Non-Patent Citations (1)

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