Induction heating method and device

Abstract

An aspect of the invention relates to an induction heating system (1) for heating a component (3). The induction heating system (1) includes a power module (21-n) for outputting an alternating current, which is operable to output the alternating current at a variable supply frequency. A controller (20) is provided to identify at least one resonant frequency () of the alternating current supplied to the at least one induction element (27-n). The controller (20) is configured to determine the operating temperature of the component (3) depending on the at least one identified resonant frequency (). An aspect of the invention also relates to an induction heating controller (20); a component (3) including an induction heating element (27-n); and a method for heating the component (3) by inductive heating.

Description

Technical Field

[0001] This disclosure relates to induction heating methods and apparatus. Aspects of the invention relate to induction heating systems; induction heating controllers; components including induction heating elements; and methods for heating components by inductive heating. Background Technology

[0002] Temperature management systems (TMS) are known to be used in industrial processes, such as in vacuum systems, to heat pipes, flanges, valves, and other components. Known TMSs traditionally use resistance heaters, which are attached to the conduits or other components to raise their temperature. Heat transfer is primarily through conduction from the resistance heater to the conduit or component. This type of TMS is ubiquitous in semiconductor vacuum processing and other processing industries. Heat is used to help reduce or prevent condensation, or to help sublimate materials in high-cost or service-disrupting areas of the system. However, known TMSs and resistance heaters have certain limitations. For example, they can cause temperature inhomogeneities, resulting in cold spots that ultimately determine the mean time between services (MTBS). Other important factors are overall temperature (there is a trend towards higher temperatures (above 150°C) for newer processes) and thermal efficiency, which drive the cost of ownership. Other important factors include cost, reliability, ease of diagnosing heater problems / failures, and ease of installation.

[0003] The purpose of this invention is to address one or more drawbacks associated with the prior art. Summary of the Invention

[0004] The present invention provides aspects and embodiments of an induction heating system; an induction heating controller; components; and methods as claimed in the appended claims.

[0005] According to an aspect of the present invention, an induction heating system for a heating component is provided, the induction heating system comprising:

[0006] At least one sensing element is used for positioning at a proximal end outside the component;

[0007] At least one power module for outputting alternating current to at least one sensing element; and

[0008] The controller is configured to identify at least one resonant frequency of the alternating current supplied to at least one sensing element;

[0009] The controller is configured to determine the operating temperature of the component based on at least one identified resonant frequency. In use, alternating current supplied to at least one sensing element generates an alternating magnetic field, which is used to generate current within the component to perform heating. The controller can determine the temperature of the component by monitoring the current supplied to the at least one sensing element. At least in some embodiments, the operating temperature of the component can be monitored without a separate temperature sensor.

[0010] The controller is configured to control the power supply frequency of the alternating current output to at least one sensing element. The controller can also be configured to control the operation of at least one power module, for example, controlling the frequency of the alternating current output to at least one sensing element. The induction heating system according to the invention generates an alternating electromagnetic field to directly generate heat in the component.

[0011] At least in some embodiments, induction heating of a component can provide improved efficiency because less electrical power is required to generate a given amount of heat, especially at higher temperature / heat input rates. Certain embodiments of induction heating systems are believed to provide improved reliability because the sensing element is less likely to be damaged, for example, during maintenance. Induction heating systems can provide improved heating uniformity, for example, when heating several zones or areas from a common controller. It is envisioned that induction heating systems can generate high temperatures, such as greater than or equal to 200°C. Since the sensing element does not need to contact the component, achieving uniform heating / temperature may be simpler, at least in some embodiments, for example, if the component has a complex geometry. Heating of the component is relatively insensitive to the sensing element or the size of the gap between each sensing element and the component. It is also possible to eliminate the need for separate temperature monitoring devices such as one or more sensors, which could increase cost and complexity, particularly during installation.

[0012] The controller can be configured to identify at least one resonant frequency of the alternating current supplied to at least one sensing element. By identifying at least one resonant frequency, the controller can selectively control power transmission to perform heating of the component.

[0013] The controller can be configured to control the power module to change the supply frequency of the alternating current. The controller can measure the current across at least one sensing element as a function of the supply frequency. The controller can control the power module to achieve substantially continuous or incremental (stepped) changes in the supply frequency.

[0014] The controller can be configured to monitor changes in the measured current depending on changes in the supply frequency of the alternating current. The controller can be configured to identify at least one peak in the measured current. This peak, or each peak, may include an increase or spike in the measured current. This peak, or each peak, may be associated with a discrete subset or region of the supply frequency. The controller can identify at least one resonant frequency corresponding to this peak, or each peak, in the measured current. Identification of at least one resonant frequency may include identifying one or more supply frequencies of the alternating current corresponding to this peak, or each peak, in the measured current. Each supply frequency that causes a peak in the measured current may indicate resonant inductive coupling. This resonant inductive coupling, or each resonant inductive coupling, is established between the sensing element, or each sensing element, and a component. Resonance causes a decrease in the phase shift between the current and the applied voltage, resulting in a decrease in circuit impedance, which leads to an increase in current across at least one sensing element. Power delivered to the component increases at the resonant frequency.

[0015] The controller can be configured to identify one or more power supply frequencies of the power module corresponding to the peak value detected in the measured current, or each peak value. For example, if more than one sensing element is connected in parallel, each peak value can correspond to a separate resonant frequency. The controller can be configured to identify multiple peak values ​​in the measured current. Each peak value can indicate the resonant frequency in a separate sensing element.

[0016] The controller can be configured to determine the phase difference between a voltage applied to at least one sensing element and a current in at least one sensing element. At least one resonant frequency can be identified based on the determined phase difference. The controller can be configured to control a power module to change the supply frequency of the alternating current and determine the phase difference. Identification of at least one resonant frequency may include identifying one or more supply frequencies that result in a phase difference that is at least substantially zero.

[0017] An induction heating system may include multiple induction elements. A controller may be configured to identify multiple resonant frequencies of the alternating current supplied to the induction elements. The controller may also identify discrete resonant frequencies for each induction element.

[0018] The controller is configured to determine the operating temperature of a component based on an identified resonant frequency. The controller may be configured to determine the operating temperature of a segment or region of a component associated with a particular one of the sensing elements. At least in some embodiments, the controller may determine the local operating temperature of a portion of the component. For example, the controller may determine the local operating temperature of a segment or region based on an identified resonant frequency of the sensing element associated with that segment or region of the component.

[0019] According to another aspect of the present invention, an induction heating system for a heating component is provided, the induction heating system comprising:

[0020] Multiple sensing elements are used to locate the proximal end of the component.

[0021] At least one power module is used to output alternating current to the sensing element; and

[0022] A controller is configured to identify multiple resonant frequencies of the alternating current supplied to at least one sensing element. The controller can identify discrete resonant frequencies for each sensing element. The controller can be configured to control the operation of at least one power module, for example, to control the frequency of the alternating current output to the sensing element.

[0023] The alternating current output to the sensing element generates an alternating magnetic field, which is used to generate current within the component to perform heating. The controller can be configured to control the power module to control the supply frequency of the alternating current.

[0024] The controller can be configured to determine the number of induction elements connected in parallel to the power module based on the resonant frequencies of multiple identifiers. Each identifier's resonant frequency can indicate an individual induction element. The controller can determine the presence of an induction element based on the resonant frequency of each identifier. The controller can count the number of identified resonant frequencies and determine that the result of this count is the total number of induction elements. The controller can identify one or more resonant frequencies, each corresponding to an induction element in the induction heating system.

[0025] The controller can be configured to determine the operating temperature of a component based on an identified resonant frequency. The controller can determine the operating temperature of a segment or region of the component associated with a particular one of the sensing elements. At least in some embodiments, the controller can determine the local operating temperature of a portion of the component. For example, the controller can determine the local operating temperature of that segment or region based on an identified resonant frequency of the sensing element associated with that segment or region of the component.

[0026] The controller can be configured to control the power module to change the supply frequency of the alternating current. The controller can measure the current across at least one sensing element as a function of the supply frequency. The controller can control the power module to achieve substantially continuous or incremental (stepped) changes in the supply frequency.

[0027] The controller can be configured to monitor changes in the measured current depending on changes in the supply frequency of the alternating current. The controller can be configured to identify multiple peaks in the measured current. Each peak may include an increase or spike in the measured current. Each peak may be associated with a discrete subset or region of the supply frequency. The controller can identify a resonant frequency corresponding to each peak in the measured current. Identification of multiple resonant frequencies may include identifying the supply frequency of the alternating current corresponding to the peak in the measured current. Each supply frequency that causes a peak in the measured current may indicate resonant inductive coupling. Resonant inductive coupling may be established between the sensing element and the component. Resonance causes a decrease in the phase shift between the current and the applied voltage, resulting in a decrease in circuit impedance, which leads to an increase in current across at least one sensing element. Power transferred to the component increases at the resonant frequency.

[0028] The controller can be configured to identify the power supply frequency of the power module corresponding to each peak detected in the measured current. For example, if more than one sensing element is connected in parallel, each peak can correspond to a separate resonant frequency. The controller can also be configured to identify multiple peaks in the measured current. Each peak can indicate the resonant frequency in a separate sensing element.

[0029] The controller can be configured to control the power module to reduce the frequency offset between the supply frequency and the identified resonant frequency, thereby increasing or maintaining component heating; and / or increase the frequency offset between the supply frequency and the identified resonant frequency to reduce component heating. This control strategy can be executed for each identified resonant frequency. If the controller identifies multiple resonant frequencies, the frequency offset between the supply frequency and the identified resonant frequency can be controlled relative to each identified resonant frequency. This control strategy enables thermal control of each of multiple sensing elements.

[0030] The controller can be configured to selectively control the power module to control the supply frequency of the alternating current output to at least one sensing element, thereby maintaining the component at a target temperature.

[0031] Alternatively or additionally, the controller can be configured to selectively control the power module to control the voltage supplied to at least one sensing element, thereby maintaining the component at a target temperature. The supply voltage can be selectively switched on and off to control the component temperature.

[0032] The controller can be configured to determine the operating temperature of the component based on the identified resonant frequency. Alternatively or additionally, the controller may have an input for receiving temperature signals from a temperature sensor such as a thermocouple.

[0033] An induction heating system may include multiple induction elements. These induction elements may be connected in parallel or in series to the power module.

[0034] Each sensing element may have one or more capacitors associated with it. The one or more capacitors associated with each sensing element may have different capacitances. The one or more capacitors associated with each sensing element may have a unique capacitance. For example, a first capacitor associated with a first sensing element may have a different capacitance than a second capacitor associated with a second sensing element. At least in some embodiments, different capacitances of the capacitors associated with sensing elements can result in different resonant frequencies for each sensing element. The controller can thus identify the presence or absence of each sensing element.

[0035] One or more capacitors may be provided in the sensing element. Alternatively or additionally, one or more capacitors may be provided in the power module.

[0036] According to another aspect of the present invention, an induction heating system for a heating component is provided, the induction heating system comprising:

[0037] A power module is used to output alternating current to a first sensing element and a second sensing element, wherein the first sensing element and the second sensing element are connected in parallel;

[0038] A first capacitor is associated with a first sensing element, and a second capacitor is associated with a second sensing element, the first and second capacitors having different capacitances. At least in some embodiments, the different capacitances of the first and second capacitors can result in different resonant frequencies of the first and second sensing elements. The induction heating system may include a controller configured to identify the presence or absence of each of the first and second sensing elements based on an identifier of the resonant frequency. It will be understood that the induction heating system may include one or more additional sensing elements, each with an associated capacitor. The capacitors in induction heating may each have different capacitances.

[0039] The first and second capacitors can be provided in the power module. Alternatively, the first and second capacitors can be provided in the first and second sensing elements, respectively.

[0040] The induction heating system may include a controller. The controller may be configured to identify first and second resonant frequencies of the alternating current supplied to the first and second induction elements. The controller may be configured to identify the presence and absence of the first and second induction elements based on the identification of the first and second resonant frequencies.

[0041] An induction heating system may include multiple power modules. Each power module may be configured to supply alternating current to one or more of a plurality of induction elements.

[0042] Power modules can be connected to each other in a daisy-chain arrangement. Power modules can be connected in series. Power modules can be connected to a common power source, such as a mains power supply. The mains power supply can be a universal voltage, for example, in the range of 100 V to 460 V.

[0043] The controllers can be configured to control the power modules independently of each other. Control signals can be transmitted from the controllers between the power modules, for example, along connections forming a daisy chain.

[0044] Each sensing element may include or consist of an inductor coil.

[0045] The component is conductive. The component may be made of, for example, metal or a metal alloy. The component may include or be composed of conduits.

[0046] According to another aspect of the invention, an induction heating controller is provided for controlling a variable frequency AC power module configured to supply alternating current to at least one induction element. The controller includes at least one processor and a memory device, wherein the at least one processor is configured to:

[0047] Change the power supply frequency of the alternating current; and

[0048] When the power supply frequency of the alternating current changes, monitor the current in at least one sensing element;

[0049] Identifying at least one resonant frequency of the alternating current supplied by the power module to at least one sensing element; and

[0050] The operating temperature of the component is determined based on at least one identified resonant frequency.

[0051] At least one processor can be configured to identify at least one resonant frequency by identifying at least one peak in the measured current that indicates at least one resonant inductive coupling.

[0052] At least one processor can be configured to determine the phase difference between a voltage applied to at least one sensing element and a current in at least one sensing element. At least one resonant frequency can be identified based on the determined phase difference. At least one processor can be configured to control a power module to change the supply frequency of the alternating current and determine the phase difference. Identification of at least one resonant frequency may include identifying the supply frequency that results in a phase difference that is at least substantially zero.

[0053] According to another aspect of the present invention, a power module for outputting alternating current to a first sensing element and a second sensing element is provided, the power module comprising:

[0054] For connection to the first output of the first sensing element; and

[0055] The second output is used to connect to the second sensing element;

[0056] The first and second outputs are configured to connect the first and second sensing elements in parallel with each other;

[0057] A first capacitor is associated with a first output, and a second capacitor is associated with a second output; the first and second capacitors have different capacitances. The different capacitances of the first and second capacitors can result in different resonant frequencies for the first and second sensing elements. When connected to the first sensing element, the first capacitor can be arranged in series with the first sensing element. When connected to the second sensing element, the second capacitor can be arranged in series with the second sensing element. A controller can be provided to detect the presence and absence of each of the first and second sensing elements based on the indicators of the different resonant frequencies.

[0058] According to another aspect of the invention, a component is provided comprising at least one integrated sensing element for connection to an alternating current (AC) power module to generate an alternating magnetic field for inducing current within the component to perform heating. The sensing element may comprise or consist of an inductor coil. An electrical insulator may be provided between the component and the inductor coil. For example, an electrically insulating sheet or panel may be provided between the component and the inductor coil. The sheet or panel may also optionally have thermal insulation properties to reduce heat loss from the component. The sensing element may be formed as a separate component and then fastened to it. The component may have an integrated construction. At least one sensing element may be permanently attached.

[0059] According to another aspect of the invention, an induction heating device is provided, comprising an induction element for connection to an alternating current (AC) power module to generate an alternating magnetic field for generating current within a conductive component to perform heating. The induction element has a longitudinally alternating configuration. The induction element may include or consist of inductor coils. The inductor coils may include a longitudinally alternating configuration. The inductor coils may be disposed in a single plane. In use, a substrate may be configured to be positioned near or in contact with the component.

[0060] Induction heating equipment may include means for electrically insulating an inductor coil. The sensing element may be disposed on an electrically insulating member for positioning against a component. The electrically insulating member may be deformable to facilitate positioning the sensing element proximal to or in contact with the component.

[0061] According to another aspect of the invention, an induction heating device is provided, which includes an induction element for connection to an alternating current (AC) power module to generate an alternating magnetic field for generating current within a conductive component to perform heating.

[0062] Induction heating devices can be configured to connect to another similar induction heating device. Induction heating devices may include connectors for connecting to similar induction heating devices. Induction heating devices can be configured to connect in parallel to another similar induction device. Induction heating devices can be configured to be connected together in a daisy-chain configuration.

[0063] Induction heating devices may include capacitors associated with a sensing element. The capacitors may be arranged in series with the sensing element. Induction heating devices can be identified within a heating induction system by identifying the resonant frequency affected by the capacitor capacitance. An assembly comprising multiple induction heating devices may be supplied, each with a different capacitance. Different capacitances can result in different resonant frequencies of the sensing element in each induction heating device. A controller may be provided to detect the presence or absence of each induction heating device based on the identification of the different resonant frequencies.

[0064] According to an aspect of the present invention, an induction heating system for a heating component is provided, the induction heating system comprising:

[0065] A power module for outputting alternating current, which can be operated to output alternating current at a variable supply frequency;

[0066] A controller for selectively controlling the power module to control the supply frequency of alternating current; and

[0067] At least one sensing element is used for positioning at a proximal end outside the component;

[0068] The power module is configured to supply alternating current to at least one sensing element to generate an alternating magnetic field, which is used to generate current inside the component to perform heating.

[0069] According to another aspect of the present invention, a method for heating a component by inductive heating is provided, the method comprising:

[0070] An alternating current is output to at least one sensing element located near the exterior of the component;

[0071] Determine at least one resonant frequency of the alternating current output to at least one sensing element; and

[0072] The operating temperature of the component is determined by at least one identified resonant frequency.

[0073] The method may include controlling the power supply frequency of the alternating current output to at least one sensing element. At least one resonant frequency may be determined as the power supply frequency changes.

[0074] The method may include measuring the current across at least one sensing element as a function of the power supply frequency. The method may include monitoring changes in the measured current depending on changes in the power supply frequency of the alternating current. Identifying at least one resonant frequency may include identifying at least one peak value in the measured current, and identifying the corresponding resonant frequency of the alternating current output by the power module.

[0075] The method may include determining the phase difference between the voltage applied to at least one sensing element and the current in the sensing element, depending on a change in the supply frequency of the alternating current. The resonant frequency, or the identifier for each resonant frequency, may include an identifier indicating when the phase difference is at least substantially zero (0).

[0076] Alternating current can be output to multiple sensing elements. These sensing elements can be connected in parallel. The method may include identifying multiple resonant frequencies of the alternating current supplied to the sensing elements. The method may include determining how many sensing elements are connected based on the multiple resonant frequencies.

[0077] Alternating current can be output to at least one sensing element to generate an alternating magnetic field, which is used to generate current inside the component to perform heating.

[0078] The method may include controlling the supply frequency of the alternating current. The controller may change the supply frequency of the alternating current supplied to at least one sensing element. The change in supply frequency may be implemented substantially continuously or incrementally.

[0079] This method may include monitoring changes in the measured current based on changes in the power supply frequency of the alternating current.

[0080] The method may include identifying at least one peak in the measured current. At least one peak may represent a decrease in impedance, which may indicate, for example, the establishment of resonant inductive coupling between the sensing element and the component. The resonant frequency of the alternating current output by the power module may be identified. When the supply frequency of the alternating current is at least substantially equal to the resonant frequency, the power delivered to the component increases.

[0081] The method may include identifying multiple peaks in the measured current. Each peak may indicate resonant inductive coupling in a corresponding sensing element.

[0082] This method may include determining how many sensing elements are connected in parallel to the power module based on the identification of at least one peak in the measured current. The method may include counting the number of peaks in the measured current to determine how many resonant frequencies occur. The result of this counting may represent the total number of sensing elements. The method may include identifying one or more peaks (representing the corresponding resonant frequencies) corresponding to one or more sensing elements.

[0083] The method may include identifying the power supply frequency of the power module corresponding to each peak detected in the measured current.

[0084] This method may include controlling the power supply frequency to control the temperature of the component. The frequency offset between the instantaneous power supply frequency and an identified resonant frequency. This method may include reducing the frequency offset to increase or maintain heating of the component. Alternatively or additionally, this method may include increasing the frequency offset to reduce heating of the component.

[0085] According to another aspect of the present invention, a method for heating a component by induction heating is provided, the method comprising:

[0086] An alternating current is output to at least one sensing element located near the exterior of the component;

[0087] Control the power supply frequency of the alternating current output to at least one sensing element;

[0088] Determine at least one resonant frequency of the alternating current output to at least one sensing element; and

[0089] The operating temperature of the component is determined by at least one identified resonant frequency.

[0090] According to another aspect of the present invention, a method for heating a component by inductive heating is provided, the method comprising:

[0091] An alternating current is output to at least one sensing element located near the exterior of the component;

[0092] Control the power supply frequency of the alternating current output to at least one sensing element; and

[0093] Determine at least one resonant frequency of the alternating current output to at least one sensing element.

[0094] This method may include determining the temperature of a component based on the identified resonant frequency. Alternatively or additionally, the method may include using a temperature sensor to transmit the temperature of the component.

[0095] It will be understood that the controller or each controller may include a control unit or computing device having one or more electronic processors (e.g., microprocessors, microcontrollers, application-specific integrated circuits (ASICs), etc.), and may include a single control unit or computing device, or alternatively, the different functions of the controller or each controller may be embodied in or hosted in different control units or computing devices. As used herein, the terms “controller,” “control unit,” or “computing device” will be understood to include a single controller, control unit, or computing device, as well as multiple controllers, control units, or computing devices that operate together to provide the desired control functions. An instruction set may be provided that, when executed, causes the controller to implement some or all of the control techniques described herein, including some or all of the functions required by the methods described herein. The instruction set may be embedded in the one or more electronic processors of the controller; or alternatively, the instruction set may be provided as software to be executed in the controller. The first controller or control unit may be implemented in software running on one or more processors. One or more other controllers or control units may be implemented in software running on one or more processors, optionally the same one or more processors as the first controller or control unit. Other arrangements are also useful.

[0096] Within the scope of this application, it is expressly intended that the various aspects, embodiments, examples, and alternatives set forth in the preceding paragraphs, claims, and / or the following description and drawings, and in particular their individual features, may be adopted independently or in any combination. That is, all embodiments and / or features of any embodiment may be combined in any manner and / or combination unless such features are incompatible. The applicant reserves the right to accordingly amend any originally filed claim or to file any new claim, including the right to modify any originally filed claim to incorporate any feature subordinate to and / or incorporated into any other claim, although not initially claimed in this manner. Attached Figure Description

[0097] One or more embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0098] Figure 1 A schematic representation of a thermal management system including an induction heating system according to an embodiment of the present invention is shown;

[0099] Figure 2 It shows the use of Figure 1 A schematic representation of the first induction heating device of the thermal management system shown in the figure;

[0100] Figure 3 A first circuit is shown representing the connection between the first induction heating element and the first power module;

[0101] Figure 4 It indicates a jump relative to the power supply frequency. Figure 3 The first graph of the current measured on the first induction heating element is shown in the figure;

[0102] Figure 5 It is a schematic representation of a thermal management system that includes a single induction heating element connected to a power module;

[0103] Figure 6 It is a diagram. Figure 5 The flowchart shown below illustrates the operation of the thermal management system.

[0104] Figure 7 This is a schematic representation of a thermal management system comprising multiple induction heating elements having power modules connected in a daisy-chain arrangement.

[0105] Figure 8 This is a schematic representation of a thermal management system that includes multiple induction heating elements connected in parallel to a common power module.

[0106] Figure 9 It shows the representation Figure 8 The second circuit shown in the figure connects the induction heating elements in parallel; and

[0107] Figure 10 It means cross Figure 9 The second graph shows the measured current on each induction heating element. Detailed Implementation

[0108] An induction heating system 1 according to an embodiment of the present invention will now be described with reference to the accompanying drawings. In this embodiment, the induction heating system 1 forms part of a thermal management system (TMS) (generally indicated by reference numeral 2). The induction heating system 1 is operable to perform inductive heating on a conductive component 3. In this embodiment, the component is in the form of a conduit 3 comprising one or more sub-segments 3-n.

[0109] The induction heating system 1 is operable to control the temperature of the exhaust system 4, which is used to deliver process gases to the emission reduction device 5. The exhaust system 4 can, for example, be provided to transport deposited gases and associated powders discharged from a chemical vapor deposition (CVD) process. The induction heating system 1 is configured to control the temperature of the exhaust system 4 to ensure that the compounds remain volatile, thereby preventing or inhibiting the accumulation of solids that may partially or completely block the exhaust system 2. It will be understood that the induction heating system 1 can be used in other industrial processes.

[0110] like Figure 1As shown, the exhaust system 4 includes a conduit 3. The conduit 3 is in the form of a tube made of metal such as stainless steel. The conduit 3 may, for example, comprise a DN40 pipe with an inner diameter of 40 mm. The conduit 3 may have a wall thickness of, for example, approximately 1 mm or 2 mm. It will be understood that the conduit 3 may have a larger or smaller wall thickness. The conduit 3 may be, for example, 10 meters or longer in length and may follow a spiral path. The conduit 3 forms a substantially continuous fluid path for conveying exhaust gases to the emission reduction device 4. The conduit 3 may consist of a single length of pipe. However, the conduit 3 typically comprises multiple sub-sections 3-1, 3-2 joined together in a fluid-tight manner. The conduit 3 may include one or more bends to provide the desired connection to the emission reduction device 4. The conduit 3 is supported along its length by multiple supports 6. An inlet coupling 9 is provided at the inlet 10 of the exhaust system 4; and an outlet coupling 11 is provided at the outlet 12 of the exhaust system 4. The outlet coupling 11 is provided to connect the exhaust system 4 to the emission reduction device 4. Inlet and outlet couplings 9 and 11 each include an O-ring for forming a fluid seal with associated components. Valve 13 is provided at outlet 12 of exhaust system 4. Valve 13 is operable to selectively open and close outlet 12. Valve 13 can be heated to reduce solid buildup. Thermal insulation 14 is provided around the exterior of conduit 3 for thermal isolation of conduit 3.

[0111] The induction heating system 1 includes a controller 20, at least one alternating current (AC) power module 21-n, and at least one induction heating device 22-n. The controller 20 includes at least one electronic processor 23 and a system memory 24. A set of computational instructions is stored in the system memory 24. When executed, the computational instructions cause the processor 23 to perform one or more methods described herein. The power module 21-n has an electrical input 25 connected to an AC power supply (RMS) or other power source; and an electrical output 26 connected to at least one induction heating device 22-n. The power module 21-n is configured to output a high-frequency alternating current. The power module 21-n may, for example, output an alternating current having a frequency greater than or equal to 10 kHz. The power module 21-n may be a radio frequency (RF) power module for outputting an alternating current having a supply frequency including an RF signal, for example, a supply frequency greater than or equal to 20 kHz. In this embodiment, the power module 21-n is configured to output an alternating current having a frequency greater than or equal to 100 kHz. In a variant, power module 21-n can be configured to generate alternating current with a frequency in the range of 100kHz to 1000kHz. In this embodiment, power module 21-n is a variable frequency AC power module (21-n). Controller 20 is connected to power module 21-n (via wired or wireless connection). Controller 20 is operable to control the operation of power module 21-n to control the supply frequency of the alternating current output via output 26 to at least one induction heating device 22-n. Figure 1 As illustrated, controller 20 transmits a control signal CS1 to power module 21-n to control the power supply frequency. Controller 20 may optionally be configured to receive one or more signals from power module 21-n. In this embodiment, controller 20 is configured to receive a current measurement signal from power module 21-n. Power module 21-n may be configured to operate at relatively low voltages (e.g., less than 40V) and relatively high currents (e.g., 10 amps).

[0112] At least one induction heating device 22-n is configured to be positioned abutting (i.e., in contact with) or closely adjacent to the conduit 3. Multiple induction heating devices 22-n may be provided on the conduit 3. The induction heating devices 22-n may be arranged on the conduit 3 in a non-overlapping manner. In this embodiment, at least one induction heating device 22-n is configured to extend at least substantially around the circumference of the conduit 3. Multiple induction heating devices 22-n may be connected in series or in parallel to the power module 21-n. Figure 1In the arrangement shown in the diagram, multiple induction heating devices 22-n are provided on the conduit 3. The induction heating devices 22-n provide multiple temperature control zones Z(n) for controlling the temperature of corresponding sections of the conduit 3. One or more induction heating devices 22-n may be provided in each temperature control zone Z(n). Each induction heating device 22-n has the same configuration. For the sake of brevity, the description herein pertains to the configuration and operation of the first induction heating device 22-1.

[0113] like Figure 2 As shown, the first induction heating device 22-1 includes an induction element 27-1, a first protective member 28, and a second protective member 29. The induction element 27-1 includes an inductor coil 30; and first and second electrical connectors 31A and 31B for connection to the output 26 of the power module 21-n. The inductor coil 30 is configured to establish a concentrated magnetic field penetrating the conduit 3. The inductor coil 30 is disposed between the first and second protective members 28 and 29. In this embodiment, the inductor coil 30 includes a conductive elongated member. The inductor coil 30 has low resistance at or within a target operating frequency range. The inductor coil 30 may be formed from one or more conductors, for example, in the form of Litz conductors; or it may be machined from a continuous sheet of conductive material. The inductor coil 30 has a longitudinally alternating configuration, for example including a sinusoidal curved configuration or a serpentine configuration, or consisting of a sinusoidal curved configuration or a serpentine configuration. The inductor coil 30 is formed in a single plane, and this arrangement is referred to herein as a “longitudinal coil.” The inductor coil 30 is supported between the first and second protective members 28 and 29. The inductor coil 30 may be engaged with at least one of the first and second protective members 28, 29. Alternatively or additionally, the first and second protective members 28, 29 may be engaged with each other to form a first induction heating device 22-1. The inductor coil 30 may be disposed in a recessed track or channel formed in at least one of the first and second protective members 28, 29.

[0114] The first protective member 28 is adapted for external positioning against the conduit 3. The first and second protective members 28, 29 are electrically insulating. The first and second protective members 28, 29 may optionally be thermally insulating to reduce heat loss from the conduit 3. The first induction heating device 22-1 is deformable to facilitate external positioning against the conduit 3, and preferably positioned around the external surface of the conduit 3. The first and second protective members 28, 29 include flexible panels. The first and second protective members 28, 29 may be formed, for example, of rubber or an elastic compound. The first induction heating device 22-1 may include at least one fastener (not shown) for securing the first induction heating device 22-1 to the conduit 3. At least one fastener may be provided, for example, on the second protective member 29. At least one fastener may be releasable to facilitate positioning and / or removal of the first induction heating device 22-1. Suitable fasteners may include hooks and fasteners disposed on the second protective member 29. Other types of fasteners may be used to secure the first induction heating device 22-1.

[0115] The induction heating system 1 in this embodiment includes at least one temperature sensor 32 for outputting a temperature signal T(n) to the controller 20. The temperature sensor 32 may include, for example, a thermistor. Figure 1 In the arrangement shown, multiple temperature sensors 32 are provided on the conduit 3. The temperature sensors 32 are associated with a separate temperature control zone Z(n) of the induction heating system 1. The temperature sensors 32 are thermally coupled to the conduit 3. The temperature sensors 32 may, for example, be coupled to the conduit 3. In a variation, the temperature sensors 32 may be incorporated into the first induction heating device 22-1, for example, in the outer surface of the first protective member 28, for external positioning against the conduit 3. Other techniques may be employed to determine the temperature of the conduit 3. As described herein, the electrical behavior of the inductor coil 30 may be monitored to determine the temperature of the conduit 3.

[0116] Figure 3The diagram shows a schematic representation of a first circuit EC1 including a power module 21-n and an induction element 27-n. As summarized above, the power module 21-n is operable to output alternating current to at least one induction heating device 22-n. An oscillating electric field in the induction element 27-n creates an oscillating magnetic field that penetrates the duct 3 of the exhaust system 4. The duct 3 is composed of a conductive material, and the changing magnetic field generates eddy currents therein. Eddy currents are effective in heating the duct 3 at a rate determined by the resistance of the duct 3. Although the first circuit EC1 has the inherent ability to store charge (i.e., capacitance), a separate capacitor 33 is added to control the electrical behavior. The induction element 27-n, capacitor 33, and resistor 34 are arranged in series in the first circuit EC1. Resistor 34 can be a discrete component provided in the first circuit EC1. Alternatively, resistor 34 can represent the resistance of an inductive load, where eddy currents generate losses, which are the source of heating. When the supply frequency is at the resonant frequency... At this point, resonant inductive coupling is established. The effective impedance of the first circuit EC1 decreases (typically to its minimum), and current and power transfer are maximized. Resonant frequency. It can be determined by the following equation:

[0117]

[0118] in: It is the resonant frequency;

[0119] It is the wavelength;

[0120] L is inductance; and

[0121] C is the capacitor.

[0122] The inductance (L) of the first circuit EC1 is a function of the material properties of the conduit 3 and the configuration of the coil formed by the induction element 27-n. Figure 4 The first graph 50 is shown, which represents the current (I) measured in the first circuit EC1 within the wavelength range of the power module 21-n output. For the purposes of this example, the resistance (R) is one (1) ohm. The inductance (L) is one (1) Henry (H); the capacitance (C) is one (1) Farad (F); and the voltage is one (1) Volt (V). Two control strategies exist for controlling the power input to the conduit 3: (a) selectively controlling the frequency of the alternating current supplied to the sensing element 27-n; and (b) modulating the supply voltage (e.g., switching the supply voltage on / off) while maintaining a fixed frequency of the alternating current. In this embodiment, the power module 21-n is a variable frequency AC power module (21-n), and the preferred control strategy is to change the supply frequency of the alternating current. The technique for controlling the alternating current frequency to control power transfer to the conduit 3 is illustrated by the arrows in the first graph 50. The controller 20 is configured to control the power module 21-n to adjust the frequency of the alternating current output to the sensing element 27-n. The controller 20 can be configured to achieve incremental changes (i.e., step changes) or substantially continuous changes in the supply frequency. The controller 20 can identify the resonant frequency by measuring the current (I) in the first circuit EC1. Resonant frequency The temperature of the substrate material, i.e., conduit 3, is affected. This is achieved by monitoring the resonant frequency. The controller 20 can estimate the temperature of the conduit 3. Therefore, the temperature of the conduit 3 can be determined without the need for the temperature sensor 32.

[0123] Figure 6 A flowchart 100 illustrating the operation of TMS 2 is shown. Alternating current is output from power module 21-n to at least one sensing element 27-n (box 110). The supply frequency of the alternating current output to at least one sensing element is changed, for example, by scanning the supply frequency within a certain range (box 120). The current (I) across at least one sensing element 27-n is measured as a function of the supply frequency (box 130). At least one peak value in the measured current is identified, and the associated supply frequency is identified as the resonant frequency (box 130). (Box 140). Determine the temperature of conduit 3 (Box 150). The temperature of conduit 3 may depend on the identified resonant frequency ( Alternatively, it may depend on the temperature signal received from temperature sensor 32. The determined temperature of conduit 3 is compared with the target temperature (box 160). Controller 20 controls the supply frequency of the alternating current based on the determined temperature of conduit 3. If the temperature of conduit 3 is lower than the target temperature, controller 20 controls the supply frequency to reduce the current supply frequency from the identified resonant frequency (…). The frequency offset between (box 170). If the temperature of conduit 3 is greater than the target temperature, controller 20 controls the power supply frequency to increase the current power supply frequency relative to the identified resonant frequency (box 170). The frequency offset between (box 180). When the industrial process is in progress, the process operates continuously.

[0124] The operation of TMS 2 will now be described in more detail. Controller 20 sets a target temperature for each temperature control zone Z(n). The target temperature can be set according to operational or process characteristics, such as depending on the composition of the exhaust gas to be transported within conduit 3. Reference will now be made to... Figure 5 The operation of an embodiment of TMS 2 including a single induction heating device 22-1 is described. The first induction heating device 22-1 is abutted against an external setting of the conduit 3 and secured in place using fasteners. The sensing element 27-1 of the first induction heating device 22-1 extends at least substantially around the circumference of the conduit 3 to facilitate uniform heating. The first induction heating device 22-1 is connected to the output 26 of a first power module (21-n) 21-1. A controller 20 is connected to the first power module (21-n) 21-1 and outputs a control signal CS1 to control the supply frequency of the alternating current output to the first induction heating device 22-1. The changing electric field in the sensing element 27-1 creates an oscillating magnetic field that induces eddy currents, which cause direct heating of the conduit 3. A temperature sensor 32 measures the temperature of the conduit 3 and outputs a temperature signal T(1) to the first power module (21-n) 21-1 and / or the controller 20. The controller 20 is configured to control the supply frequency of the alternating current depending on the measured temperature. If the temperature signal T(n) indicates that the measured temperature is lower than the target temperature, the controller 20 is configured to change the power supply frequency (by increasing or decreasing the power supply frequency) to be closer to the resonant frequency. The frequency is adjusted to increase power transmission. The current power supply frequency is related to the identified resonant frequency. The frequency offset between them is thus reduced to increase the heating of the component. If the temperature signal T(n) indicates that the measured temperature is higher than the target temperature, the controller 20 is configured to change the power supply frequency (by increasing or decreasing the power supply frequency) so that it is further away from the resonant frequency. This is to reduce power transmission. Therefore, the current power supply frequency is related to the identified resonant frequency. The frequency offset between them is increased in order to reduce the heating of the components.

[0125] As summarized above, resonant frequency It varies depending on temperature. Resonant frequency. The relationship between the measured temperature of conduit 3 and the temperature of the conduit 3 can be predefined, for example, in a lookup table stored in system memory 24. The controller 20 can therefore depend on the determined resonant frequency. To determine the temperature of conduit 3. Alternatively or additionally, controller 20 can be configured to control power modules 21-n to change the supply frequency to determine the resonant frequency. The power supply frequency can vary within a certain range, for example, by performing a scan or sweep. The controller 20 can, for example, change the power supply frequency between a lower frequency limit and a higher frequency limit. In this embodiment, the controller 20 is configured to change the power supply frequency substantially continuously between the lower and upper frequency limits. In a variant, the controller 20 can be configured to implement incremental changes, such as including multiple step changes in the power supply frequency. When the power supply frequency changes, the controller 20 measures the current (i1) across the first induction heating device 22-1. The controller 20 is configured to identify the peak value in the measured current (i1) as a function of the power supply frequency. The peak value can be identified by determining when the rate of change of the measured current is at least substantially equal to zero (0) when the power supply frequency changes. The controller 20 will use the resonant frequency... The frequency is identified as corresponding to the peak current. The controller 20 can selectively increase or decrease the supply frequency depending on whether the rate of change of the measured current is positive or negative, in order to determine the resonant frequency. Alternatively, controller 20 can measure the current at a predefined range of supply frequencies. This process can be performed periodically, for example, as a calibration operation.

[0126] Figure 7 The diagram illustrates the development of TMS 2. This implementation of TMS 2 includes multiple induction heating devices 22-n, each associated with a separate section of conduit 3. In this arrangement, TMS 2 includes multiple temperature control zones Z(n), each including at least one induction heating device 22-n. In the illustrated arrangement, TMS 2 includes four (4) induction heating devices 22-1, 22-2, 22-3, 22-4 and four (4) associated power modules 21-1, 21-2, 21-3, 21-4. The induction heating devices 22-1, 22-2, 22-3, 22-4 are each connected to a corresponding power module 21-1, 21-2, 21-3, 21-4. The power modules 21-1, 21-2, 21-3, 21-4 are daisy-chained together and powered via a common line voltage connection, thereby minimizing the number of connections returning to the central distribution board. Power modules 21-1, 21-2, 21-3, and 21-4 each receive a temperature signal T(n) from their associated temperature sensor 32. Controller 20 is configured to control the supply frequency of the alternating current output from each of the power modules 21-1, 21-2, 21-3, and 21-4 based on the temperature signal T(n). The supply frequency of the alternating current output to each induction heating device 22-1, 22-2, 22-3, and 22-4 is independently controllable. Therefore, the temperature of each individual temperature control zone Z(n) can be controlled independently.

[0127] Power module 21-n can be configured to communicate directly with controller 20 (e.g., in...) Figure 5(Indicated by the dashed lines shown). In a variant, power modules 21-n are configured to communicate with each other via a daisy-chain line voltage connection. Each power module 21-n is configured to transmit and receive signals via the line voltage connection. The first power module (21-n) 21-1 associated with the first induction heating device 22-1 can serve as the master unit for direct communication with the controller 20. The second, third, and fourth power modules 21-2, 21-3, and 21-4 associated with the subsequent induction heating devices 22-2, 22-3, and 22-4 serve as slave units. This connection provides the advantage of providing a single point of communication connection for the controller 20. In this arrangement, the line voltage connection is operable to transmit the control signal CS1 to the corresponding power module 21-n to control the power supply frequency output to each induction heating device 22-2, 22-3, and 22-4. The temperature signal T(n) and other operating signals can optionally be transmitted via the line voltage connection. The current across each induction heating device 22-2, 22-3, 22-4 can be optionally measured and transmitted via line voltage connection. It will be understood that each power module 21-n is operable independently of the other power modules 21-n. The power demand at the AC connection is equal to the sum of the individual power demands of each AC power module (21-n) unit 21.

[0128] Figure 8 The figure illustrates another embodiment of TMS 2. The same reference numerals are used for the same components. TMS 2 includes multiple temperature control zones Z(n), each temperature control zone including at least one segment of the conduit 3. TMS 2 includes multiple induction heating devices 22-n, each induction heating device connected in parallel to a common power module 21-n. In the illustrated embodiment, three (3) induction heating devices 22-1, 22-2, 22-3 are connected in parallel to a first power module (21-n) 21-1. The first, second, and third induction heating devices 22-1, 22-2, 22-3 are each associated with a separate segment of the conduit 3 (corresponding to a separate temperature control zone Z(n)). The temperature of the separate segments of the conduit 3 can be controlled independently.

[0129] Figure 9The diagram shows a second circuit EC2 representing this embodiment of TMS 2. The second circuit EC2 includes multiple branches connected in parallel to the AC power supply module 21-1. Each branch corresponds to one of the temperature control zones Z(n). In the illustrated arrangement, the second circuit EC2 includes three (3) branches, but it will be understood that the second circuit EC2 may include two (2) branches or more than three (3) branches. The second circuit EC2 includes first, second, and third capacitors 33-1, 33-2, and 33-3, each having a first, second, and third capacitor C1, C2, and C3, respectively. The first, second, and third capacitors 33-1, 33-2, and 33-3 may each have different capacitances C1, C2, and C3 to vary the resonant frequency of each branch of the second circuit EC2. The current in each branch of the second circuit EC2 depends on the supply frequency of the current output from the first power module (21-n) 21-1. It will be understood that more than one induction heating device 22-n can be provided in each temperature control zone Z(n), for example, two or more induction heating devices 22-n can be connected in series in each branch of the second circuit EC2.

[0130] Controller 20 is configured to control power module 21-n to change the supply frequency in order to determine the resonant frequency of each branch of the second circuit EC2. The power supply frequency can vary within a certain range, for example, between a lower frequency limit and a higher frequency limit. In this embodiment, the controller 20 controls the power modules 21-n such that the power supply frequency varies substantially continuously. As the power supply frequency varies across this range, the current (I) in each branch of the second circuit EC2 is measured. In this embodiment, the controller 20 measures the first current (i1), the second current (i2), and the third current (i3) across the first, second, and third induction heating devices 22-1, 22-2, and 22-3, respectively. The controller 20 is operable to identify the peak value of each of the first current (i1), the second current (i2), and the third current (i3) as a function of the power supply frequency. The peak value of each of the first current (i1), the second current (i2), and the third current (i3) is related to the resonant frequency of each of the first, second, and third induction heating devices 22-1, 22-2, and 22-3. Correspondingly, controller 20 is configured to depend on the resonant frequency of each branch of the second circuit EC2. The temperature of each segment of conduit 3 is determined. The controller 20 can also adjust the power supply frequency by controlling the AC power supply module 21-1, thereby controlling the temperature of each segment of conduit 3. Alternatively or additionally, the temperature of each segment of conduit 3 can be changed by selectively adjusting the inductance and / or capacitance of each branch of the second circuit EC2.

[0131] Controller 20 is described as measuring the current (I) across each of the induction heating devices 22-1, 22-2, and 22-3. The total current (I) is equal to the sum of the first current (i1), the second current (i2), and the third current (i3) (i.e., I = i1 + i2 + i3). The first current (i1), the second current (i2), and the third current (i3) are each a vector with phase and module described in the complex domain. The total current (I) can be measured, and the resonant frequency is determined by detecting one or more peaks in the total current (I) as a function of the supply frequency. The presence or absence of [the current]. Controller 20 can monitor the total current (I) and count the total number of peaks present in the total current (I) across the supply frequency range. The identifier of each peak in the total current (I) indicates the resonant frequency of the individual temperature control zones connected in parallel to the power modules 21-n. By determining the number of peak values ​​across the power supply frequency range, controller 20 can determine how many (n) induction heating devices 22-n are connected. Controller 20 can determine that no induction heating devices 22-n are connected (i.e., n = 0); or that one or more induction heating devices 22-n are connected (n >= 1). Controller 20 can thus determine how many temperature control zones Z(n) are connected to power modules 21-n. The ability to determine how many induction heating devices 22-n are connected enables the implementation of automated or semi-automated control systems.

[0132] Figure 10 The second graph 60 is shown, representing the current (I) measured in the second circuit EC2 within the wavelength range of the output of the first power module (21-n) 21-1. The power module 21-n is a variable frequency AC power module (21-n), and the control strategy includes controlling the supply frequency of the alternating current output to the sensing elements 27-1, 27-2, and 27-3. The controller 20 can be configured to implement incremental changes (i.e., step changes) or substantially continuous changes in the supply frequency. By measuring the first current (i1), the second current (i2), and the third current (i3), the controller 20 can identify the resonant frequency of each sensing element 27-1, 27-2, and 27-3. Resonant frequency The temperature of the substrate material, i.e., conduit 3, is affected. This is achieved by monitoring the resonant frequency. The controller 20 can estimate the temperature of each segment of the conduit 3. The controller 20 is configured to control the first power module (21-n) 21-1 based on the determined temperature of the corresponding segment of the conduit 3.

[0133] Variable capacitors and / or variable inductors can be provided in each branch of the second circuit EC2. Controller 20 can be configured to control the capacitors and / or inductors in each branch to adjust the resonant frequency of each sensing element 27-1, 27-2, 27-3. .

[0134] At least one induction heating device 22-n is described herein as a separate device located on conduit 3. In a variant, induction heating device 22-n may be integrated into component 3. In particular, induction element 27-n may be integrated into conduit 3. Induction element 27-n may include a helix extending circumferentially around conduit 3. Alternatively, induction element 27-n may include a longitudinal coil of the type described herein, extending at least partially circumferentially around conduit 3. Induction element 27-n will be electrically insulated from conduit 3 and optionally also thermally insulated from conduit 3. For example, an electrically insulating sheath may be provided around the exterior of conduit 3. Each segment 3-1, 3-2 of conduit 3 may include an electrical connector. The electrical connector may be used to connect induction elements 27-n to each other (e.g., in parallel or in series) and / or to power modules 21-n(one or more). Conduit 3 may include coupling means for forming a fluid seal with adjacent conduit 3. A thermal insulation layer and / or an electrical insulation layer may be provided around the exterior of induction element 27-n.

[0135] It will be understood that various changes and modifications can be made to this invention without departing from the scope of this application.

[0136] The controller 20, as described herein, determines the resonant frequency by measuring the current i1 across the first induction heating device 22-1 when the power supply frequency changes. Resonant frequency The supply frequency is identified as corresponding to the peak value in the measured current (i1). It will be understood that other techniques can be used to determine the resonant frequency. For example, the resonant frequency can be determined by monitoring the phase of the current and the voltage applied to the sensing element 27-n. At resonance, the phase is null because the circuit is purely resistive (corresponding to the maximum power transmitted). If the frequency is greater than the resonant frequency... (f > If the frequency is less than the resonant frequency, the circuit behaves more like an inductor, where the current "lags behind" the voltage. (f < In this case, the circuit behaves more like a capacitor, where the current "leads" the voltage. Therefore, phase detection can be used to determine the resonant frequency. The controller 20 can be configured to control the frequency of the alternating current supplied to the sensing element 27-n based on a determined phase.

[0137] Reference number

[0138] Number part 1 Induction heating system 2 Thermal Management System (TMS) 3 catheter 4 Exhaust system 5 Emission reduction equipment 6 Support components 9 Inlet Coupler 10 Entrance 11 Output coupler 12 exit 13 valve 14 Insulation layer 20 controller 21-n Power Module 22-n Induction heating equipment 23 processor 24 System memory 25 Electrical input 26 Electrical output 27-n Sensing element 28 First protective component 29 Second protective component 30 Inductor coil 30 31A, 31B electrical connectors 32 Temperature sensor 33 capacitor 34 resistors 50 First curve graph 60 Second curve graph 100 flow chart T(n) Temperature signal CS(n) control signals

Claims

1. An induction heating system (1) for a heating component (3), the induction heating system (1) comprising: Multiple sensing elements (27-n) are used for positioning on the proximal end outside the component (3); At least one power module (21-n) is used to output alternating current to the plurality of sensing elements (27-n); and The controller (20) is configured to identify multiple resonant frequencies (f0) of the alternating current supplied to the plurality of sensing elements (27-n); in The controller (20) is configured to determine the operating temperature of component (3) based on the identified resonant frequency (f0), and At least one of the power modules (21-n) is a frequency conversion AC power module and has an electrical input for connection to the mains power supply. One of the at least one power modules (21-n) is used as a master unit that communicates directly with the controller (20), while the other power module in the at least one power module (21-n) is used as a slave unit.

2. The induction heating system (1) according to claim 1, wherein the controller (20) is configured as follows: Control the power module (21-n) to change the supply frequency of the alternating current; and Measure the current across the plurality of sensing elements (27-n) as a function of the power supply frequency; The multiple resonant frequencies (f0) identified include the power supply frequency of the alternating current that corresponds to multiple peak values ​​in the measured current.

3. The induction heating system (1) according to claim 1, wherein, The controller is configured as follows: Control the power module (21-n) to change the supply frequency of the alternating current; and Determine the phase difference between the voltage applied to the plurality of sensing elements (27-n) and the current in the sensing elements (27-n); wherein identifying the plurality of resonant frequencies (f0) includes identifying the power supply frequency that results in a phase difference of at least substantially zero (0).

4. An induction heating system (1) for a heating component (3), the induction heating system (1) comprising: Multiple sensing elements (27-n) are used for positioning on the proximal end outside the component (3); At least one power module (21-n) is used to output alternating current to the sensing element (27-n); and The controller (20) is configured to identify multiple resonant frequencies (f0) of the alternating current supplied to the plurality of sensing elements (27-n). At least one of the power modules (21-n) is a frequency conversion AC power module and has an electrical input for connection to the mains power supply. One of the at least one power modules (21-n) is used as a master unit that communicates directly with the controller (20), while the other power module in the at least one power module (21-n) is used as a slave unit.

5. The induction heating system (1) according to claim 4, wherein, The controller (20) is configured to determine the operating temperature of the component (3) based on the identified resonant frequency (f0).

6. The induction heating system (1) according to any one of the preceding claims, wherein, The controller (20) is configured to determine how many sensing elements (27-n) are connected in parallel to the power module (21-n) depending on the number of identified resonant frequencies (f0).

7. The induction heating system (1) according to any one of claims 4-5, wherein, The controller (20) is configured to control the power module (21-n) to reduce the frequency offset between the power supply frequency and the identified resonant frequency (f0), thereby increasing or maintaining the heating of the component (3); and / or increasing the frequency offset between the power supply frequency and the identified resonant frequency (f0) to reduce the heating of the component (3).

8. The induction heating system (1) according to any one of claims 4-5, wherein, The sensing element (27-n) is connected in parallel to the power module (21-n).

9. The induction heating system (1) according to claim 8, wherein, Each sensing element (27-n) has an associated capacitor (C1, C2, C3), and each capacitor (C1, C2, C3) has a different capacitance.

10. An induction heating system (1) for a heating component (3), the induction heating system (1) comprising: A power module (21-1) is used to output alternating current to a first sensing element (27-1) and a second sensing element (27-2), wherein the first sensing element (27-1) and the second sensing element (27-2) are connected in parallel. A first capacitor (C1) associated with the first sensing element (27-1) and a second capacitor (C2) associated with the second sensing element (27-2), the first and second capacitors (C1, C2) having different capacitances. The power module (21-1) is a variable frequency AC power module and has an electrical input connected to the mains power supply. The power module (21-1) includes multiple power modules (21-n), each power module (21-n) being configured to supply alternating current to one or more of multiple sensing elements (27-n). One of the multiple power modules (21-n) serves as a master unit that communicates directly with the controller (20), while the other power modules (21-n) serve as slave units.

11. The induction heating system (1) according to claim 10, wherein, The power modules (21-n) are connected to each other in a daisy chain arrangement.

12. The induction heating system (1) according to claim 10 or 11, wherein, The controller (20) is configured to control the power modules (21-n) independently of each other.

13. An induction heating controller (20) for controlling a variable frequency AC power module (21-n), the variable frequency AC power module (21-n) having an electrical input connected to an AC power source and configured to supply alternating current to a plurality of induction elements (27-n), the controller (20) including at least one processor and a memory device, said at least one processor being configured to: Change the power supply frequency of the alternating current; and When the power supply frequency of the alternating current changes, the current in the plurality of sensing elements (27-n) is monitored; The multiple resonant frequencies (f0) of the alternating current supplied by the power module (21-n) to the multiple sensing elements (27-n) are identified; and The operating temperature of component (3) is determined by the resonant frequency (f0) of the identifier, wherein one of the power modules (21-n) is used as the master unit that communicates directly with the controller (20), while the other power module in the power modules (21-n) is used as a slave unit.

14. A component (3) comprising at least one integrated sensing element (27-n) for connection to a variable frequency AC power module (21-n) to generate an alternating magnetic field for generating current within the component (3) to perform heating, wherein the variable frequency AC power module (21-n) has an electrical input connected to an AC power source, wherein one of the power modules (21-n) serves as a master unit that communicates directly with a controller (20), while the other power module (21-n) serves as a slave unit.

15. An induction heating device (22-n) including induction elements (27-n) for connection to a variable frequency AC power module (21-n) to generate an alternating magnetic field for generating current inside a conductive component (3) to perform heating, the induction elements (27-n) having a longitudinally alternating configuration, wherein the variable frequency AC power module (21-n) has an electrical input for connection to an AC power source, wherein one of the power modules (21-n) serves as a master unit for direct communication with a controller (20), while the other power module (21-n) serves as a slave unit.

16. The induction heating device (22-n) according to claim 15, wherein, The sensing element (27-n) is disposed on an electrically insulating member for positioning against the component (3), wherein the member is deformable to facilitate positioning the sensing element (27-n) near the component (3) or in contact with the component (3).

17. A method for heating a component (3) by inductive heating, the method comprising: Alternating current is output to multiple sensing elements (27-n) located near the outside of component (3); Determine multiple resonant frequencies (f0) of the alternating current output from the power module (21-n) to the plurality of sensing elements, the power module (21-n) having an electrical input connected to an AC power source; and The operating temperature of component (3) is determined by the resonant frequency (f0) of the identifier, wherein one of the power modules (21-n) is used as the master unit that communicates directly with the controller (20), while the other power module in the power modules (21-n) is used as a slave unit.

18. The method of claim 17, comprising measuring the current across the plurality of sensing elements (27-n) as a function of the power supply frequency, and monitoring changes in the measured current depending on changes in the power supply frequency of the alternating current; The plurality of resonant frequencies (f0) are identified by at least one peak value in the measured current and by the corresponding resonant frequency (f0) of the alternating current output by the power module (21-n).

19. The method of claim 17, further comprising determining the phase difference between the voltage applied to the plurality of sensing elements (27-n) and the current in the sensing elements (27-n) depending on the change in the supply frequency of the alternating current; The identification of the resonant frequency (f0) or each resonant frequency (f0) includes identifying when the phase difference is at least substantially zero (0).

20. The method according to any one of claims 17 to 19, comprising determining how many sensing elements (27-n) are connected depending on the plurality of resonant frequencies (f0).

21. The method according to any one of claims 17 to 19, comprising reducing the frequency offset between the power supply frequency and the identified resonant frequency (f0) to increase or maintain the heating of the component (3); and / or increasing the frequency offset between the power supply frequency and the identified resonant frequency (f0) to reduce the heating of the component (3).

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