EP3136822B1 - Method for determining a temperature - Google Patents
Method for determining a temperature Download PDFInfo
- Publication number
- EP3136822B1 EP3136822B1 EP16184674.6A EP16184674A EP3136822B1 EP 3136822 B1 EP3136822 B1 EP 3136822B1 EP 16184674 A EP16184674 A EP 16184674A EP 3136822 B1 EP3136822 B1 EP 3136822B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- induction heating
- cooking vessel
- coil
- measuring
- water
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims description 29
- 238000010438 heat treatment Methods 0.000 claims description 200
- 230000006698 induction Effects 0.000 claims description 144
- 238000010411 cooking Methods 0.000 claims description 141
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 97
- 230000004044 response Effects 0.000 claims description 18
- 238000009835 boiling Methods 0.000 claims description 13
- 230000010355 oscillation Effects 0.000 claims description 7
- 238000009529 body temperature measurement Methods 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 230000001939 inductive effect Effects 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 230000000630 rising effect Effects 0.000 description 3
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Images
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
-
- 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
- H05B6/062—Control, e.g. of temperature, of power for cooking plates or the like
- H05B6/065—Control, e.g. of temperature, of power for cooking plates or the like using coordinated control of multiple induction coils
-
- 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
- H05B6/12—Cooking devices
-
- 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
- H05B2213/03—Heating plates made out of a matrix of heating elements that can define heating areas adapted to cookware randomly placed on the heating plate
-
- 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 method for determining the temperature in an induction hob with a plurality of induction heating coils.
- an induction hob and a method for its operation with a temperature determination are known.
- a large number of infrared sensors are provided for this purpose, which are arranged in the center of induction heating coils. This allows the temperature of a cooking vessel to be detected, which is placed above the induction heating coil for heating it and thus also above the IR sensor.
- the invention has for its object to provide a method mentioned above, with which problems of the prior art can be solved and in particular it is possible to carry out the temperature determination in the cooking vessel advantageously and accurately, in particular to determine when water boils in the cooking vessel.
- a cooking vessel with water or a liquid mainly containing water in it is placed on the induction hob in such a way that there are at least two induction heating coils covered. It advantageously covers three to five induction heating coils, which are then made correspondingly small, for example with diameters or widths in the range between 6 cm and 18 cm.
- These induction heating coils detect the coverage by the cooking vessel, in particular to a previously defined extent or with a predefined coverage level, for example at least 50% of the area of the induction heating coil.
- each induction heating coil heats the region of the cooking vessel base arranged above it in a known manner.
- the energy input occurs in the lowest area of the bottom of the cooking vessel, usually the lowest 1mm to 2mm. From there, the heat spreads upwards to the top of the bottom of the cooking vessel and from there it is transferred into the water.
- the induction heating coils of a hotplate work advantageously with the same power level or resulting area power density of the power transferred into the vessel.
- the vibration response on at least one induction heating coil is used to determine whether the temperature of the bottom of the cooking vessel changes over this induction heating coil or whether this temperature rises.
- a temperature gradient of the bottom of the cooking vessel can be detected by the induction heating coil, which is preferred according to a method such as that mentioned in the introduction EP 2330866 A2 is described. The content of this is hereby made express reference to the content of the present application. If this determination of the vibration response takes place only periodically, it should be about once per second, advantageously every 0.1 seconds to 2 seconds.
- the vibration response of an induction heating coil can be understood as the evaluation of the change in the resonant circuit parameters due to temperature changes in the bottom of the cooking vessel, in particular the changing inductance.
- the vibration response of each induction heating coil can preferably be recorded.
- the induction heating coils are operated in heating mode at least until an induction heating coil detects that the temperature gradient of the bottom of the cooking vessel is above zero or becomes zero.
- a temperature of a cooking vessel base heated by means of an induction heating coil is advantageously determined.
- the method comprises the steps: creating one Intermediate circuit voltage at least temporarily as a function of a single-phase or multi-phase, in particular three-phase, AC mains voltage, generating a high-frequency drive voltage or a drive current from the intermediate circuit voltage, for example with a frequency in a range from 20 kHz to 70 kHz, and applying a resonant circuit comprising the induction heating coil with the drive voltage the control current.
- induction heating of the bottom of the cooking vessel takes place conventionally.
- the following steps are carried out for temperature measurement: generation of the intermediate circuit voltage during predetermined periods, in particular periodically, with a constant voltage level, the intermediate circuit voltage being preferably generated independently of the mains alternating voltage during the periods, generation of the drive voltage during the predetermined periods such that the resonant circuit essentially dampens at its natural resonance frequency, measuring at least one oscillation parameter of the oscillation during the predetermined time periods and evaluating the at least one measured oscillation parameter to determine the temperature. Since the intermediate circuit voltage is kept constant during the temperature measurement, signal influences due to a variable intermediate circuit voltage can be eliminated, which enables reliable and interference-free temperature determination.
- the method comprises the steps: determining zero crossings of the AC line voltage and selecting the time segments in the area of the zero crossings.
- the DC link voltage usually decreases sharply.
- the constant voltage level is preferably selected such that it is greater than the voltage level which is usually set in the region of the zero crossings, so that the intermediate circuit voltage is clamped to the constant voltage level in the region of the zero crossings. Then there are constant voltage conditions in the area of the zero crossings, which enable reliable temperature measurement.
- the induction heating coils are all operated in heating mode at least until a first induction heating coil detects that the temperature gradient of the area of the cooking vessel bottom above this induction heating coil becomes zero. All induction heating coils can also be operated in heating mode until the temperature gradient of the cooking vessel base located above them becomes zero over each of the induction heating coils. If the temperature gradient becomes zero, this means that the temperature of the cooking vessel base does not increase any further, which in turn means that the water in the cooking vessel is directly above this cooking vessel base region or at the boundary layer between Water and the bottom of the cookware boil, so the temperature does not increase any further.
- the temperature of the water directly at the bottom of the cooking vessel particularly when inductively heating a cooking vessel with water, at which very high powers are introduced into the bottom of the cooking vessel, which is intended to cause the water to boil very quickly can quickly increase to 100 ° C at least in some areas. This is where the typical detachment of very large water vapor bubbles takes place, which is where the water boils or bubbles. However, not all of the water in the cooking vessel has yet reached the temperature of 100 ° C, which is actually desirable.
- induction cooktops can be set to a very high output with the well-known boost function for boiling, the formation and detachment of water vapor bubbles occurs when the temperature of the water in the upper area is only about 80 away from the boundary layer between the water and the bottom of the cooking vessel ° C to 90 ° C, so it is still clearly away from cooking or the corresponding 100 ° C.
- high heat flows for example approx. 10W / cm 2
- temperature differences between the water temperature and the inside of the pot bottom of approx. 10 ° C to 40 ° C occur.
- the bottom of the cooking vessel has a further temperature difference of approx. 10 ° C between the inside and the outside.
- the invention determines at least one of the induction heating coils as a measuring coil. Several methods can be used for this, which will be carried out in more detail later.
- This measuring coil is then operated in measuring mode and no longer in heating mode, with the change or stopping of heating mode not necessarily having to take place immediately after being determined as a measuring coil.
- the measuring coil In measuring mode itself, the measuring coil is operated with a so-called measuring power of up to 10% or 20%, advantageously a maximum of 50%, of the maximum power for a short time, in particular only for a half-wave, or transmits correspondingly little or less energy to the over area of the bottom of the cooking vessel. Up to 20% of the maximum power, the measuring power can be regarded as a small power.
- the measuring coil detects the feedback vibration response in the aforementioned manner.
- the time course of this vibration response is then evaluated after coupling the low energy several times, that is to say essentially a procedure similar to that used previously for recording the vibration response at each induction heating coil. Then, in the event that the gradient of this time course becomes zero, the water in the cooking vessel is determined to be boiling, namely all of the water.
- the vibration response is really recorded on every induction heating coil.
- the measuring coil can already be determined beforehand, for example as the induction heating coil with the lowest degree of coverage or the worst power input into the bottom of the cooking vessel. Then only their vibration response needs to be evaluated.
- the measuring coil no longer heats the bottom of the cooking vessel and, as a result, the true temperature of the water in the cooking vessel or the heat flow through the pot bottom and the heat flow in the transition can be detected in the area of the cooking vessel bottom above the measuring coil
- the bottom of the pot becomes infinitesimally small and the true temperature of the water and the temperature of the inside and the bottom of the cooking vessel become the same.
- series-connected temperature differences of about 10 ° C to 40 ° C from the inside of the cooking vessel to water and about 10 ° C between the inside and outside of the cooking vessel become almost zero.
- the water in the cooking vessel Due to the already started formation of bubbles in the water on the bottom of the cooking vessel, the water in the cooking vessel is mixed to a certain extent, in particular by the rising water. This is not enough to bring all the water in the cooking vessel to a boil very quickly, by repeatedly bringing some cooler water to the bottom of the cooking vessel for heating due to the decrease in heat. In the unheated area of the bottom of the cooking vessel above the measuring coil, however, it is very likely that cooler water will be present, both due to the lack of heating and due to the mixing of the water in the cooking vessel. By stopping the heating operation of the measuring coil, an effect that falsifies the measurement result is exposed.
- the measuring coil works at least a certain time after the determination as a measuring coil only as a kind of sensor.
- the coupling of a signal or a power for generating the vibration response for its evaluation can be regarded as negligible with regard to heating the area of the cooking vessel base directly above the measuring coil.
- an essential essence of the invention is to make a temperature determination in a method for boiling water in a cooking vessel, for which several induction heating coils are used, more precise by using one of the induction heating coils as a measuring coil and then no longer working in heating mode, but only in measurement mode. In this way, falsifications of the measurement result are avoided or at least greatly reduced. This reduces the total heating output for the cooking vessel, but increases the accuracy. On the one hand, it is possible to quickly remove the measuring coil from heating mode to switch to measuring mode, for example after it or possibly another induction heating coil has detected a temperature of 100 ° C. on the bottom of the cooking vessel for the first time because the temperature gradient of the vibration response has become zero.
- induction heating coil it is possible to determine that induction heating coil as the measuring coil whose temperature gradient of the vibration response first becomes zero during the general heating operation and above all during its own heating operation. This is, so to speak, the induction heating coil with the hottest area of the cooking vessel bottom above itself at this time.
- the induction heating coil can also be determined and used as the measuring coil in which this temperature gradient ultimately becomes zero. This is then the induction heating coil that has the coolest area of the cooking vessel bottom above it. Then it can be assumed that the water in the cooking vessel as a whole is already significantly closer to the state that it is boiling overall or is completely around 100 ° C.
- induction heating coil as the measuring coil which has the lowest power input into the cooking vessel and / or which has the lowest degree of coverage by the cooking vessel.
- the first criterion can be determined during heating operation and can also be checked repeatedly or permanently, for example.
- the second criterion can already be determined at the beginning of the cooking process, that is, if it is determined at all which induction heating coils are covered by the cooking vessel and which consequently start the heating operation as a common cooking point.
- this criterion should also be checked during heating operation, since it may well happen that the cooking vessel is above the induction heating coils or is moved on the hotplate and then the degree of coverage of individual or all induction heating coils changes.
- all induction heating coils are of identical design, that is to say they are of the same size. This simplifies the manufacture of an induction hob. Furthermore, it is advantageously also possible to operate all induction heating coils, which together form a hotplate for a single cooking vessel, identically. This applies above all to the performance level. This means that induction heating coils with a recognized lower degree of coverage can also be operated in the same way as induction heating coils with a high or complete degree of coverage.
- the heating operation of all induction heating coils that work for this cooking vessel or this hotplate remains constant for a certain time Service is continued.
- This time should be less than 1 minute and can be, for example, at least 10 seconds, advantageously at least 20 seconds.
- the previously determined measuring coil is then operated in measuring mode, advantageously with the aforementioned measuring power.
- the measuring coil which has either already been determined beforehand or is only determined thereby, does not immediately come out of the heating mode is taken, because then the total heating output at the hotplate would be unnecessarily reduced.
- the heating is continued with the maximum possible output for rapid heating. Only after a certain time will the measuring coil be operated in measuring mode, since only then can it be expected that the 100 ° C in the entire water will soon be reached. This time can also be varied depending on how much water needs to be brought to the boil or how large the cooking vessel is. For this purpose, for example, the previous duration can be used as a criterion when the first induction heating coil detects the temperature gradient that has become zero.
- the measuring coil is not the first induction heating coil that can be used, but the last induction heating coil, the temperature gradient of which becomes zero. Even then, even the measuring coil can continue to be operated in heating mode for a certain time, since even in this case the bottom of the cooking vessel is everywhere 100 ° C, most likely not all of the water in the cooking vessel is 100 ° C.
- This time for the continued operation of the measuring coil in heating mode should be significantly shorter than 1 minute and can in particular be shorter than the previously mentioned time, for example 5 seconds to 20 seconds.
- the measuring coil is only operated in measuring mode after this time has elapsed, although again it may either have been determined as the measuring coil either at the beginning of the heating mode or only later.
- the power of the measuring coil has been significantly reduced or if it is only operated as a measuring coil with the measuring power, to equate the time course of the water temperature of the water in the cooking vessel with the time course of the period of the vibration response at the Measuring coil, at least as far as the relative course is concerned.
- This measuring coil then works as a temperature sensor for the region of the cooking vessel base lying above it, which in turn determines the temperature of the water in the cooking vessel brought to it by swirling.
- This area of the bottom of the cooking vessel then works, so to speak, as a first part of a sensor.
- the second part of this sensor is the measuring coil, which queries the temperature of this first part, so to speak.
- the measuring operation of the measuring coil should advantageously be such that it does not bring any additional heating power into the area of the cooking vessel bottom above it, in order to reduce falsifications in temperature detection or temperature determination or to avoid them as far as possible.
- a half-wave can already suffice for the power input, which in turn is then only carried out with the aforementioned low power or measuring power.
- FIG. 1 is shown schematically how a plurality of individual induction heating coils 13, here with a round shape, can be present in an induction hob 11.
- a cooking vessel 15 is set up in such a way that it covers four induction heating coils 13a to 13d by more than 50%.
- the induction heating coils 13b and 13d are completely covered, and the induction heating coils 13a and 13c to about 70% to 80%.
- the cooking vessel 15 has a cooking vessel base 16 which is suitable for inductive heating and usually has a thickness of a few millimeters, for example 4 mm to 10 mm.
- a cooking vessel base 16 is of multilayer design with an uppermost layer, which consists of the same material as the side wall of the cooking vessel 15 and is usually produced by deep drawing, that is to say with a one-piece material transition.
- a heat-distributing layer of copper with a thickness of a few millimeters is often arranged underneath.
- a thin layer of stainless steel can be provided, which is also suitable for inductive heating.
- Their thickness can be a maximum of 1mm to 2mm. At the same time, this is approximately the maximum penetration depth of inductive fields, which will be explained below.
- the induction heating coils 13a and 13b are connected to a controller 19 of the induction hob 11 and are supplied with power in a controlled manner, usually via a power unit (not shown here) or corresponding resonant circuit arrangements.
- the thin arrows show a power input 21a and 21b from each of the induction heating coils 13a and 13b into the cooking vessel 15 and into the cooking vessel bottom 16. This is known to the person skilled in the art and need not be discussed in more detail. As previously mentioned, the depth of penetration of the power input 21 is less than 2 mm, advantageously less than 1 mm. From this lowermost layer of the cooking vessel base 16, the heat generated is distributed upward through the further structure of the cooking vessel base 16, possibly with a corresponding transverse distribution. At the top of the cooking vessel base 16, the heat transfer takes place in the water 17 located above it in the cooking vessel 15. This heated water rises as a result of the heat introduced, which is illustrated by the broad arrows. Of course, a kind of mixing of the water flows 23a and 23b takes place, also shown here by further water flows 23.
- the temperature T W of the water 17 in the cooking vessel 15 is recorded as a kind of average temperature, ie not only measured at individual discrete points, but as an average at many points. In particular, this can also be a temperature at the water surface, where the temperature of the water 17 will usually be the lowest when boiling.
- the temperature of the water above the left induction heating coil 21a near the cooking vessel base 16 is shown with a thick dashed line.
- the water 17 will probably be the hottest and the quickest to boil.
- the temperature of the water is 17th the value of 100 ° C is shown.
- the course heights are approximately to scale relative to each other.
- the measured value or the period signal of the induction heating coil 13b which is used as the measuring coil in the measuring operation is shown with a thin solid line.
- the dashed thin line shows the period signal of the induction heating coil 13a operated in heating mode.
- these two period signals do not have to be of different sizes, this is only shown here for the sake of clarity in order to better show their relative courses. In particular, they can be largely congruent, especially at the beginning.
- the controller 19 detects in a known manner which induction heating coils are covered at all and to what extent or with what degree of coverage.
- the induction heating coils 13 of the configuration of the Fig. 1 the aforementioned induction heating coils 13a to 13d are sufficiently covered. If an operator has now selected a power level for operating the induction hob 11, with which the water 17 in the cooking vessel 15 is to be brought to a boil as quickly as possible, the heating operation of the four induction heating coils 13a to 13d starts.
- the induction heating coils 13a and 13b generate a power input 21a and 21b in the cooking vessel bottom 16, in particular in its bottom layer.
- the inductively generated heat spreads upwards and enters or is transferred to the water 17 at the top of the cooking vessel base 16. This creates water flows 23, in particular strong water flows 23a and 23b rising from the top of the cooking vessel base 16.
- the induction heating coil 13b can now be determined as the measuring coil, since it has the recognizable lowest degree of coverage by the cooking vessel 15 or the cooking vessel base 16. This determination can be made even if the measuring coil 13b is also operated together with the others in heating mode as a hotplate. Alternatively, this can be done in Fig. 4 Period signal shown in dashed lines, which will initially be relatively the same for most induction heating coils, can be evaluated for each induction heating coil 13. Then the induction heating coil can be determined as the measuring coil and switch to measuring mode, in which the gradient first becomes approximately zero. In in yet another embodiment of the invention, that induction heating coil can be used as the measuring coil in the measuring mode, in which this curve becomes the last to be constant or has zero slope compared to the other induction heating coils.
- this case applies that the slope has become the last to be zero for the induction heating coil 13b. This means that the temperature above all other induction heating coils 13 of the hotplate is higher or was previously high.
- the dashed water temperature at the time when the slope of the period signal of one of the induction heating coils becomes zero also comes to the shown maximum value of 100 ° C. as the water temperature.
- this is the temperature of the water just above the bottom 16 of the cooking vessel above the induction heating coil with the course of the period signal shown in dashed lines.
- the thick solid line as the temperature T W of the water 17 in the cooking vessel 15 rises approximately constant at the beginning after a short delay.
- the induction heating coil 13b which is now operated in measuring mode as a measuring coil with the measuring power, has the continuous course with the thin line.
- the measuring power is, for example, 5% of the maximum power.
- the course of the period signal at the measuring coil 13b also shows that after the change to the measuring mode, this measuring coil transmits almost no energy into the bottom of the cooking vessel and thus does not attempt to heat it up. Since the water 17 in the cooking vessel 15 does not yet have a total of 100.degree. C., that is to say does not yet boil overall, but instead only has, for example, only 80.degree. C. to 90.degree. C., this relatively cooler water falls back onto this area of the cooking vessel bottom and cools it to less than 100 ° C.
- the conditions in the cooking vessel 15 during this period are in Fig. 3 to see.
- the induction heating coil 13a in the heating mode also causes the power input 21a into the cooking vessel bottom 16 above it, which generates the strong water flow 23a. This circulates, so to speak, and has the effect that water 17 located in the upper area appears as a water flow 23 shown with thin arrows down onto the area of the cooking vessel base 16 which lies above the measuring coil 13b.
- experience values which can be stored in the control 19 as explained above, can also allow a certain continuation time be determined for the induction heating coil 13b in heating mode, after which the water in the cooking vessel 15 is still not completely boiled.
- the total or average temperature of the entire water has reached about 100 ° C. due to the continuous power input of the remaining three induction heating coils, which advantageously takes place with the same or maximum output, in particular after sufficient mixing of the from the bottom 16 of the heating coils heated water with the rest of the water.
- the thin and solid period signal of the measuring coil again has the slope zero or becomes constant, then all the water 17 boils in the cooking vessel 15. This also applies to the temperature T W of the water.
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Cookers (AREA)
- Induction Heating Cooking Devices (AREA)
Description
Die Erfindung betrifft ein Verfahren zur Temperaturbestimmung bei einem Induktionskochfeld mit mehreren Induktionsheizspulen.The invention relates to a method for determining the temperature in an induction hob with a plurality of induction heating coils.
Aus der
Aus der
Aus der
Der Erfindung liegt die Aufgabe zugrunde, ein eingangs genanntes Verfahren zu schaffen, mit dem Probleme des Stands der Technik gelöst werden können und es insbesondere möglich ist, die Temperaturbestimmung im Kochgefäß vorteilhaft und genau durchzuführen, insbesondere zu bestimmen, wenn Wasser in dem Kochgefäß kocht.The invention has for its object to provide a method mentioned above, with which problems of the prior art can be solved and in particular it is possible to carry out the temperature determination in the cooking vessel advantageously and accurately, in particular to determine when water boils in the cooking vessel.
Gelöst wird diese Aufgabe durch ein Verfahren mit den Merkmalen des Anspruchs 1. Vorteilhafte sowie bevorzugte Ausgestaltungen der Erfindung sind Gegenstand der weiteren Ansprüche und werden im Folgenden näher erläutert. Der Wortlaut der Ansprüche wird durch ausdrückliche Bezugnahme zum Inhalt der Beschreibung gemacht.This object is achieved by a method having the features of claim 1. Advantageous and preferred embodiments of the invention are the subject of the further claims and are explained in more detail below. The wording of the claims is made the content of the description by express reference.
Bei dem Verfahren, das in einem Induktionskochfeld mit mehreren einzeln ansteuerbaren Induktionsheizspulen durchgeführt wird, werden folgende Schritte durchgeführt:
Ein Kochgefäß mit Wasser oder einer hauptsächlich Wasser enthaltenden Flüssigkeit darin wird so auf das Induktionskochfeld aufgestellt, dass es mindestens zwei Induktionsheizspulen überdeckt. Vorteilhaft überdeckt es drei bis fünf Induktionsheizspulen, die dann eben entsprechend klein ausgebildet sind, beispielsweise mit Durchmessern bzw. Breiten im Bereich zwischen 6cm und 18cm. Diese Induktionsheizspulen erkennen die Überdeckung durch das Kochgefäß, insbesondere in einem vorher definierten Ausmaß bzw. mit einem vordefinierten Überdeckungsgrad, beispielsweise mindestens 50% der Fläche der Induktionsheizspule. Diese entsprechend überdeckten Induktionsheizspulen werden dann als gemeinsame Kochstelle gemeinsam betrieben, und zwar im Heizbetrieb bzw. für den Kochvorgang, um das Wasser in dem Kochgefäß durch Heizen zum Kochen zu bringen. Dieses Kochen des Wassers soll eben erfindungsgemäß als Temperaturbestimmung erfasst werden.The following steps are carried out in the process, which is carried out in an induction hob with a plurality of individually controllable induction heating coils:
A cooking vessel with water or a liquid mainly containing water in it is placed on the induction hob in such a way that there are at least two induction heating coils covered. It advantageously covers three to five induction heating coils, which are then made correspondingly small, for example with diameters or widths in the range between 6 cm and 18 cm. These induction heating coils detect the coverage by the cooking vessel, in particular to a previously defined extent or with a predefined coverage level, for example at least 50% of the area of the induction heating coil. These correspondingly covered induction heating coils are then operated together as a common hotplate, specifically in heating mode or for the cooking process, in order to bring the water in the cooking vessel to a boil by heating. This boiling of the water is to be recorded according to the invention as a temperature determination.
Während des dann folgenden Heizbetriebs beheizt jede Induktionsheizspule den über ihr angeordneten Bereich des Kochgefäßbodens auf bekannte Art und Weise. Der Energieeintrag erfolgt dabei in den untersten Bereich des Kochgefäßbodens, üblicherweise die untersten 1mm bis 2mm. Von dort aus breitet sich die Wärme nach oben an die Oberseite des Kochgefäßbodens aus und von dort wird sie ins Wasser übertragen. Die Induktionsheizspulen einer Kochstelle arbeiten dabei vorteilhaft mit gleicher Leistungsstufe bzw. resultierender Flächenleistungsdichte der ins Gefäß übertragenen Leistung.During the subsequent heating operation, each induction heating coil heats the region of the cooking vessel base arranged above it in a known manner. The energy input occurs in the lowest area of the bottom of the cooking vessel, usually the lowest 1mm to 2mm. From there, the heat spreads upwards to the top of the bottom of the cooking vessel and from there it is transferred into the water. The induction heating coils of a hotplate work advantageously with the same power level or resulting area power density of the power transferred into the vessel.
Während des Heizbetriebs wird anhand der Schwingungsantwort an mindestens einer Induktionsheizspule erfasst, ob sich die Temperatur des Kochgefäßbodens über dieser Induktionsheizspule ändert bzw. ob diese Temperatur ansteigt. So kann ein Temperaturgradient des Kochgefäßbodens von der Induktionsheizspule erfasst werden, was bevorzugt gemacht wird entsprechend einem Verfahren, wie es in der eingangs genannten
Vorteilhaft wird im Heizbetrieb eine Temperatur eines mittels einer Induktionsheizspule erwärmten Kochgefäßbodens ermittelt. Das Verfahren umfasst die Schritte: Erzeugen einer Zwischenkreisspannung zumindest zeitweise in Abhängigkeit von einer einphasigen oder mehrphasigen, insbesondere dreiphasigen, Netzwechselspannung, Erzeugen einer hochfrequenten Ansteuerspannung oder eines Ansteuerstroms aus der Zwischenkreisspannung, beispielsweise mit einer Frequenz in einem Bereich von 20kHz bis 70kHz, und Beaufschlagen eines Schwingkreises umfassend die Induktionsheizspule mit der Ansteuerspannung bzw. dem Ansteuerstrom. Auf diese Weise erfolgt herkömmlich eine induktive Erwärmung des Kochgefäßbodens. Zur Temperaturmessung werden folgende Schritte durchgeführt: Erzeugen der Zwischenkreisspannung während vorgegebener Zeitabschnitte, insbesondere periodisch, mit einem konstanten Spannungspegel, wobei während der Zeitabschnitte bevorzugt die Zwischenkreisspannung unabhängig von der Netzwechselspannung erzeugt wird, Erzeugen der Ansteuerspannung während der vorgegebenen Zeitabschnitte derart, dass der Schwingkreis im Wesentlichen entdämpft mit seiner Eigenresonanzfrequenz schwingt, Messen mindestens eines Schwingungsparameters der Schwingung während der vorgegebenen Zeitabschnitte und Auswerten des mindestens einen gemessenen Schwingungsparameters zum Ermitteln der Temperatur. Da die Zwischenkreisspannung während der Temperaturmessung konstant gehalten wird, können Signalbeeinflussungen aufgrund einer veränderlichen Zwischenkreisspannung eliminiert werden, wodurch eine zuverlässige und störsichere Temperaturermittlung ermöglicht wird.In heating mode, a temperature of a cooking vessel base heated by means of an induction heating coil is advantageously determined. The method comprises the steps: creating one Intermediate circuit voltage at least temporarily as a function of a single-phase or multi-phase, in particular three-phase, AC mains voltage, generating a high-frequency drive voltage or a drive current from the intermediate circuit voltage, for example with a frequency in a range from 20 kHz to 70 kHz, and applying a resonant circuit comprising the induction heating coil with the drive voltage the control current. In this way, induction heating of the bottom of the cooking vessel takes place conventionally. The following steps are carried out for temperature measurement: generation of the intermediate circuit voltage during predetermined periods, in particular periodically, with a constant voltage level, the intermediate circuit voltage being preferably generated independently of the mains alternating voltage during the periods, generation of the drive voltage during the predetermined periods such that the resonant circuit essentially dampens at its natural resonance frequency, measuring at least one oscillation parameter of the oscillation during the predetermined time periods and evaluating the at least one measured oscillation parameter to determine the temperature. Since the intermediate circuit voltage is kept constant during the temperature measurement, signal influences due to a variable intermediate circuit voltage can be eliminated, which enables reliable and interference-free temperature determination.
In einer Weiterbildung umfasst das Verfahren die Schritte: Bestimmen von Nulldurchgängen der Netzwechselspannung und Wählen der Zeitabschnitte im Bereich der Nulldurchgänge. Im Bereich der Nulldurchgänge bei einphasiger Netzwechselspannung nimmt die Zwischenkreisspannung üblicherweise stark ab. Der konstante Spannungspegel wird bevorzugt derart gewählt, dass er größer als der sich üblicherweise im Bereich der Nulldurchgänge einstellende Spannungspegel ist, sodass die Zwischenkreisspannung im Bereich der Nulldurchgänge auf den konstanten Spannungspegel geklemmt wird. Es herrschen dann im Bereich der Nulldurchgänge konstante Spannungsverhältnisse, die eine zuverlässige Temperaturmessung ermöglichen.In one development, the method comprises the steps: determining zero crossings of the AC line voltage and selecting the time segments in the area of the zero crossings. In the area of zero crossings with single-phase AC mains voltage, the DC link voltage usually decreases sharply. The constant voltage level is preferably selected such that it is greater than the voltage level which is usually set in the region of the zero crossings, so that the intermediate circuit voltage is clamped to the constant voltage level in the region of the zero crossings. Then there are constant voltage conditions in the area of the zero crossings, which enable reliable temperature measurement.
Die Induktionsheizspulen werden mindestens so lange alle im Heizbetrieb betrieben, bis eine erste Induktionsheizspule erfasst, dass der Temperaturgradient des Bereichs des Kochgefäßbodens über dieser Induktionsheizspule zu Null wird. Es können auch alle Induktionsheizspulen so lange im Heizbetrieb betrieben werden, bis über jeder der Induktionsheizspulen der Temperaturgradient des darüber befindlichen Kochgefäßbodens zu Null wird. Wenn der Temperaturgradient zu Null wird bedeutet dies, dass sich die Temperatur des Kochgefäßbodens nicht weiter erhöht, was wiederum bedeutet, dass das Wasser im Kochgefäß direkt über diesem Kochgefäßbodenbereich bzw. an der Grenzschicht zwischen Wasser und Kochgefäßboden kocht, sich die Temperatur also nicht weiter erhöht. Nun hat sich aber im Rahmen der Erfindung herausgestellt, dass sich gerade beim induktiven Beheizen eines Kochgefäßes mit Wasser darin, bei dem sehr hohe Leistungen in den Kochgefäßboden eingebracht werden, was ein sehr schnelles Kochen des Wassers bewirken soll, die Temperatur des Wassers direkt am Kochgefäßboden zumindest bereichsweise sehr schnell auf 100°C erhöhen kann. Dort erfolgt dann auch schon die für das Kochen typische Ablösung von teils sehr großen Wasserdampfblasen, dort kocht das Wasser also bzw. sprudelt. Allerdings hat dann noch nicht unbedingt das gesamte Wasser im Kochgefäß die Temperatur von 100°C erreicht, was ja aber eigentlich gewünscht ist. Und weil bei Induktionskochfeldern mit der bekannten Boost-Funktion zum Ankochen eine sehr hohe Leistung eingestellt werden kann, gibt es die Bildung und Ablösung von Wasserdampfblasen bereits dann, wenn die Temperatur des Wassers im oberen Bereich entfernt von der Grenzschicht zwischen Wasser und Kochgefäßboden nur etwa 80°C bis 90°C aufweist, also noch deutlich vom Kochen bzw. den entsprechenden 100°C entfernt ist. Bei hohen Wärmeströmen, beispielsweise ca. 10W/cm2, kommen also Temperaturdifferenzen zwischen der Wassertemperatur und der Topfbodeninnenseite von ca. 10°C bis 40°C zu Stande. Zusätzlich hat der Kochgefäßboden zwischen Innenseite und Außenseite eine weitere Temperaturdifferenz von ca. 10°C.The induction heating coils are all operated in heating mode at least until a first induction heating coil detects that the temperature gradient of the area of the cooking vessel bottom above this induction heating coil becomes zero. All induction heating coils can also be operated in heating mode until the temperature gradient of the cooking vessel base located above them becomes zero over each of the induction heating coils. If the temperature gradient becomes zero, this means that the temperature of the cooking vessel base does not increase any further, which in turn means that the water in the cooking vessel is directly above this cooking vessel base region or at the boundary layer between Water and the bottom of the cookware boil, so the temperature does not increase any further. However, it has now been found within the scope of the invention that the temperature of the water directly at the bottom of the cooking vessel, particularly when inductively heating a cooking vessel with water, at which very high powers are introduced into the bottom of the cooking vessel, which is intended to cause the water to boil very quickly can quickly increase to 100 ° C at least in some areas. This is where the typical detachment of very large water vapor bubbles takes place, which is where the water boils or bubbles. However, not all of the water in the cooking vessel has yet reached the temperature of 100 ° C, which is actually desirable. And because induction cooktops can be set to a very high output with the well-known boost function for boiling, the formation and detachment of water vapor bubbles occurs when the temperature of the water in the upper area is only about 80 away from the boundary layer between the water and the bottom of the cooking vessel ° C to 90 ° C, so it is still clearly away from cooking or the corresponding 100 ° C. At high heat flows, for example approx. 10W / cm 2 , temperature differences between the water temperature and the inside of the pot bottom of approx. 10 ° C to 40 ° C occur. In addition, the bottom of the cooking vessel has a further temperature difference of approx. 10 ° C between the inside and the outside.
Demzufolge bestimmt die Erfindung mindestens eine der Induktionsheizspulen als Messspule. Dazu können mehrere Verfahren genommen werden, die später noch genauer ausgeführt werden.Accordingly, the invention determines at least one of the induction heating coils as a measuring coil. Several methods can be used for this, which will be carried out in more detail later.
Diese Messspule wird dann im Messbetrieb und nicht mehr im Heizbetrieb betrieben, wobei der Wechsel bzw. das Stoppen des Heizbetriebs nicht zwingend sofort nach Bestimmung als Messspule erfolgen muss. Im Messbetrieb selbst wird die Messspule mit einer sogenannten Mess-Leistung bis 10% oder 20%, vorteilhaft maximal 50%, der maximalen Leistung für kurze Zeit, insbesondere nur für eine Halbwelle, betrieben bzw. überträgt entsprechend wenig bzw. geringere Energie in den über der Messspule liegenden Bereich des Kochgefäßbodens. Bis zu 20% der maximalen Leistung kann die Mess-Leistung als kleine Leistung angesehen werden. Dann erfasst die Messspule die zurückgekoppelte Schwingungsantwort auf zuvor genannte Art und Weise. Dann wird der zeitliche Verlauf dieser Schwingungsantwort nach mehreren Malen Einkoppeln der geringen Energie ausgewertet, also im Wesentlichen ein ähnliches Verfahren angewendet wie schon zuvor bei der Erfassung der Schwingungsantwort an jeder Induktionsheizspule. Dann wird in dem Fall, dass der Gradient dieses zeitlichen Verlaufs zu Null wird, das Wasser in dem Kochgefäß als kochend bestimmt, und zwar das gesamte Wasser.This measuring coil is then operated in measuring mode and no longer in heating mode, with the change or stopping of heating mode not necessarily having to take place immediately after being determined as a measuring coil. In measuring mode itself, the measuring coil is operated with a so-called measuring power of up to 10% or 20%, advantageously a maximum of 50%, of the maximum power for a short time, in particular only for a half-wave, or transmits correspondingly little or less energy to the over area of the bottom of the cooking vessel. Up to 20% of the maximum power, the measuring power can be regarded as a small power. The measuring coil then detects the feedback vibration response in the aforementioned manner. The time course of this vibration response is then evaluated after coupling the low energy several times, that is to say essentially a procedure similar to that used previously for recording the vibration response at each induction heating coil. Then, in the event that the gradient of this time course becomes zero, the water in the cooking vessel is determined to be boiling, namely all of the water.
Dabei ist es nicht zwingend notwendig, dass die Schwingungsantwort wirklich an jeder Induktionsheizspule erfasst wird. Unter Umständen kann die Messspule nämlich bereits zuvor bestimmt werden, beispielsweise als diejenige Induktionsheizspule mit dem geringsten Überdeckungsgrad bzw. dem schlechtesten Leistungseintrag in den Kochgefäßboden. Dann braucht nur deren Schwingungsantwort ausgewertet zu werden.It is not absolutely necessary that the vibration response is really recorded on every induction heating coil. Under certain circumstances, the measuring coil can already be determined beforehand, for example as the induction heating coil with the lowest degree of coverage or the worst power input into the bottom of the cooking vessel. Then only their vibration response needs to be evaluated.
Mit der Erfindung wird nämlich im Wesentlichen bewirkt, dass die Messspule nicht mehr den Kochgefäßboden heizt und dadurch im Bereich des Kochgefäßbodens über der Messspule sozusagen eher die wahre Temperatur des Wassers im Kochgefäß erfasst werden kann bzw. der Wärmestrom durch den Topfboden sowie der Wärmestrom im Übergang Topfboden zu Wasser verschwindend klein werden und dadurch die wahre Temperatur des Wassers und die Temperatur der Kochgefäßinnenseite als auch der -unterseite gleich werden. Die zuvor beschriebenen, in Reihe geschalteten, Temperaturdifferenzen von etwa 10°C bis 40°C von Kochgefäßinnenseite zu Wasser und etwa 10°C zwischen Kochgefäßinnen- und -außenseite werden annähernd zu Null. Durch die bereits begonnene Blasenbildung im Wasser am Kochgefäßboden wird das Wasser im Kochgefäß in gewissem Maß durchgemischt, insbesondere durch das aufsteigende Wasser. Dies reicht zwar nicht, um sehr schnell das gesamte Wasser im Kochgefäß zum Kochen zu bringen, indem immer wieder etwas kühleres Wasser an den Kochgefäßboden herangetragen wird zur Erwärmung aufgrund Wärmeabnahme. In dem unbeheizten Bereich des Kochgefäßbodens über der Messspule wird aber mit großer Wahrscheinlichkeit eher kühleres Wasser vorhanden sein, und zwar sowohl aufgrund der fehlenden Beheizung als auch aufgrund der Durcheinandermischung des Wassers im Kochgefäß. Durch das Stoppen des Heizbetriebs der Messspule wird also eine das Messergebnis verfälschende Wirkung ausgesetzt. Die Messspule arbeitet zumindest eine bestimmte Zeit nach der Bestimmung als Messspule nur noch als eine Art Sensor. Das Einkoppeln eines Signals bzw. einer Leistung zur Erzeugung der Schwingungsantwort für deren Auswertung kann als vernachlässigbar angesehen werden bezüglich einer Erhitzung des Bereichs des Kochgefäßbodens direkt über der Messspule.With the invention it is essentially brought about that the measuring coil no longer heats the bottom of the cooking vessel and, as a result, the true temperature of the water in the cooking vessel or the heat flow through the pot bottom and the heat flow in the transition can be detected in the area of the cooking vessel bottom above the measuring coil The bottom of the pot becomes infinitesimally small and the true temperature of the water and the temperature of the inside and the bottom of the cooking vessel become the same. The previously described, series-connected temperature differences of about 10 ° C to 40 ° C from the inside of the cooking vessel to water and about 10 ° C between the inside and outside of the cooking vessel become almost zero. Due to the already started formation of bubbles in the water on the bottom of the cooking vessel, the water in the cooking vessel is mixed to a certain extent, in particular by the rising water. This is not enough to bring all the water in the cooking vessel to a boil very quickly, by repeatedly bringing some cooler water to the bottom of the cooking vessel for heating due to the decrease in heat. In the unheated area of the bottom of the cooking vessel above the measuring coil, however, it is very likely that cooler water will be present, both due to the lack of heating and due to the mixing of the water in the cooking vessel. By stopping the heating operation of the measuring coil, an effect that falsifies the measurement result is exposed. The measuring coil works at least a certain time after the determination as a measuring coil only as a kind of sensor. The coupling of a signal or a power for generating the vibration response for its evaluation can be regarded as negligible with regard to heating the area of the cooking vessel base directly above the measuring coil.
Somit besteht ein wesentlicher Kern der Erfindung darin, eine Temperaturbestimmung bei einem Verfahren zum Kochen von Wasser in einem Kochgefäß, wofür mehrere Induktionsheizspulen verwendet werden, dadurch genauer zu machen, dass eine der Induktionsheizspulen als Messspule verwendet wird und dazu dann nicht mehr im Heizbetrieb arbeitet, sondern nur noch im Messbetrieb. So werden Verfälschungen des Messergebnisses vermieden oder zumindest stark reduziert. Damit wird zwar die gesamte Heizleistung für das Kochgefäß reduziert, dafür steigt aber die Genauigkeit. Einerseits ist es möglich, die Messspule schnell vom Heizbetrieb auf den Messbetrieb umzustellen, beispielsweise nachdem sie oder eventuell auch eine andere Induktionsheizspule zum ersten Mal dadurch, dass der Temperaturgradient der Schwingungsantwort zu Null geworden ist, eine Temperatur von 100°C am Kochgefäßboden erfasst hat. Da erfahrungsgemäß dann aber der Großteil des in dem Kochgefäß befindlichen Wassers noch nicht kocht bzw. noch nicht die 100°C erreicht hat, wird es andererseits als vertretbar und insgesamt vorteilhafter angesehen, auch die Messspule dann noch für eine bestimmte eher kurze Zeit im Heizbetrieb zu betreiben, beispielsweise 10 Sekunden bis 60 Sekunden oder sogar 300 Sekunden. Es ist nämlich in aller Regel erst dann damit zu rechnen, dass auf die gesamte Wassermenge bezogen bald die 100°C bzw. der kochende Zustand vorliegen. Auch hierzu sind Varianten möglich, die nachfolgend näher erläutert werden.Thus, an essential essence of the invention is to make a temperature determination in a method for boiling water in a cooking vessel, for which several induction heating coils are used, more precise by using one of the induction heating coils as a measuring coil and then no longer working in heating mode, but only in measurement mode. In this way, falsifications of the measurement result are avoided or at least greatly reduced. This reduces the total heating output for the cooking vessel, but increases the accuracy. On the one hand, it is possible to quickly remove the measuring coil from heating mode to switch to measuring mode, for example after it or possibly another induction heating coil has detected a temperature of 100 ° C. on the bottom of the cooking vessel for the first time because the temperature gradient of the vibration response has become zero. However, since experience has shown that the majority of the water in the cooking vessel is not yet boiling or has not yet reached 100 ° C, on the other hand it is considered justifiable and generally more advantageous to also close the measuring coil in heating mode for a certain rather short time operate, for example 10 seconds to 60 seconds or even 300 seconds. It is usually only then to be expected that the total amount of water will soon reach 100 ° C or the boiling state. Variants are also possible here, which are explained in more detail below.
In Ausgestaltung der Erfindung ist es möglich, diejenige Induktionsheizspule als Messspule zu bestimmen, deren Temperaturgradient der Schwingungsantwort während des allgemeinen Heizbetriebs und vor allem auch während ihres eigenen Heizbetriebs zuerst zu Null wird. Dies ist dann sozusagen die Induktionsheizspule mit dem zu diesem Zeitpunkt heißesten Bereich des Kochgefäßbodens über sich. Alternativ dazu kann auch diejenige Induktionsheizspule als Messspule bestimmt und verwendet werden, bei der dieser Temperaturgradient zuletzt zu Null wird. Dies ist dann entsprechend diejenige Induktionsheizspule, die den kühlsten Bereich des Kochgefäßbodens über sich aufweist. Dann kann davon ausgegangen werden, dass das Wasser im Kochgefäß insgesamt bereits deutlich näher an dem Zustand ist, dass es insgesamt kocht bzw. vollständig etwa 100°C aufweist. Während bei der ersten Alternative noch mit einer relativ längeren Zeit des Heizbetriebs zu rechnen ist, bis das gesamte Wasser kocht, beispielsweise 20 Sekunden bis 40 Sekunden, ist bei der zweiten Alternative eher nur mit einer kürzeren Zeit zu rechnen, beispielsweise 5 Sekunden bis 20 Sekunden. Dies ist bei den weiteren Vorgehensmöglichkeiten für die Temperaturbestimmung und für den Betrieb der Induktionsheizspulen zu beachten.In an embodiment of the invention, it is possible to determine that induction heating coil as the measuring coil whose temperature gradient of the vibration response first becomes zero during the general heating operation and above all during its own heating operation. This is, so to speak, the induction heating coil with the hottest area of the cooking vessel bottom above itself at this time. As an alternative to this, the induction heating coil can also be determined and used as the measuring coil in which this temperature gradient ultimately becomes zero. This is then the induction heating coil that has the coolest area of the cooking vessel bottom above it. Then it can be assumed that the water in the cooking vessel as a whole is already significantly closer to the state that it is boiling overall or is completely around 100 ° C. While in the first alternative a relatively longer time of heating operation can be expected until all the water boils, for example 20 seconds to 40 seconds, in the second alternative only a shorter time is to be expected, for example 5 seconds to 20 seconds . This has to be taken into account in the further procedure options for temperature determination and for the operation of the induction heating coils.
In weiterer Ausgestaltung der Erfindung ist es möglich, diejenige Induktionsheizspule als Messspule zu bestimmen, die den geringsten Leistungseintrag in das Kochgefäß und/oder die den geringsten Überdeckungsgrad durch das Kochgefäß aufweist. Das erste Kriterium kann während des Heizbetriebs ermittelt werden und beispielsweise auch wiederholt oder permanent überprüft werden. Das zweite Kriterium kann bereits zu Beginn des Kochvorgangs bestimmt werden, also wenn überhaupt bestimmt wird, welche Induktionsheizspulen von dem Kochgefäß überdeckt sind und welche demzufolge überhaupt als gemeinsame Kochstelle mit dem Heizbetrieb starten. Dabei sollte aber auch dieses Kriterium während des Heizbetriebs überprüft werden, da es durchaus vorkommen kann, dass das Kochgefäß über den Induktionsheizspulen bzw. auf der Kochstelle bewegt wird und sich dann der Überdeckungsgrad einzelner oder aller Induktionsheizspulen ändert.In a further embodiment of the invention, it is possible to determine that induction heating coil as the measuring coil which has the lowest power input into the cooking vessel and / or which has the lowest degree of coverage by the cooking vessel. The first criterion can be determined during heating operation and can also be checked repeatedly or permanently, for example. The second criterion can already be determined at the beginning of the cooking process, that is, if it is determined at all which induction heating coils are covered by the cooking vessel and which consequently start the heating operation as a common cooking point. However, this criterion should also be checked during heating operation, since it may well happen that the cooking vessel is above the induction heating coils or is moved on the hotplate and then the degree of coverage of individual or all induction heating coils changes.
In vorteilhafter Ausgestaltung der Erfindung sind sämtliche Induktionsheizspulen identisch ausgebildet, also vor allem auch gleich groß. Dies vereinfacht die Herstellung eines Induktionskochfelds. Des Weiteren ist es vorteilhaft auch möglich, sämtliche Induktionsheizspulen, die gemeinsam eine Kochstelle für ein einziges Kochgefäß bilden, identisch zu betreiben. Dies gilt vor allem für die Leistungsstufe. Also können auch Induktionsheizspulen mit einem erkannten geringeren Überdeckungsgrad genauso betrieben werden wie Induktionsheizspulen mit einem hohen oder vollständigen Überdeckungsgrad.In an advantageous embodiment of the invention, all induction heating coils are of identical design, that is to say they are of the same size. This simplifies the manufacture of an induction hob. Furthermore, it is advantageously also possible to operate all induction heating coils, which together form a hotplate for a single cooking vessel, identically. This applies above all to the performance level. This means that induction heating coils with a recognized lower degree of coverage can also be operated in the same way as induction heating coils with a high or complete degree of coverage.
In einer Ausgestaltung der Erfindung ist es möglich, dass dann, nachdem die erste Induktionsheizspule einen Temperaturgradienten aufweist bzw. erfasst, der zu Null geworden ist, für eine bestimmte Zeit der Heizbetrieb aller Induktionsheizspulen, die für dieses Kochgefäß bzw. diese Kochstelle arbeiten, mit gleichbleibender Leistung weitergeführt wird. Diese Zeit sollte weniger als 1 Minute betragen und kann beispielsweise mindestens 10 Sekunden betragen, vorteilhaft mindestens 20 Sekunden betragen. Nach Ablauf dieser Zeit wird die zuvor bestimmte Messspule dann im Messbetrieb betrieben, vorteilhaft mit der vorgenannten Mess-Leistung. Hier wird also berücksichtigt, dass in dem zuvor bereits genannten Fall, dass die erste Stelle des Kochgefäßbodens eine Temperatur von etwa 100°C aufweist, die Messspule, die entweder zuvor bereits bestimmt worden ist oder erst dadurch bestimmt wird, doch nicht sofort aus dem Heizbetrieb genommen wird, da dann die gesamte Heizleistung an der Kochstelle unnötig reduziert werden würde. Durch das Weiterheizen aller Induktionsheizspulen, insbesondere auch der Messspule, wird, da davon ausgegangen werden kann, dass das Wasser im Kochgefäß noch keine 100°C hat, noch mit maximal möglicher Leistung weitergeheizt für ein schnelles Aufheizen. Erst nach der gewissen Zeit wird dann die Messspule im Messbetrieb betrieben, da erst dann damit zu rechnen ist, dass die 100°C im gesamten Wasser bald erreicht sein werden. Diese Zeit kann auch variiert werden abhängig davon, wieviel Wasser zum Kochen gebracht werden muss bzw. wie groß das Kochgefäß ist. Dazu kann beispielsweise die bisherige Dauer als Kriterium herangezogen werden, wann eben die erste Induktionsheizspule den zu Null gewordenen Temperaturgradienten erfasst.In one embodiment of the invention, it is possible that after the first induction heating coil has or detects a temperature gradient that has become zero, the heating operation of all induction heating coils that work for this cooking vessel or this hotplate remains constant for a certain time Service is continued. This time should be less than 1 minute and can be, for example, at least 10 seconds, advantageously at least 20 seconds. After this time, the previously determined measuring coil is then operated in measuring mode, advantageously with the aforementioned measuring power. It is therefore taken into account here that, in the case already mentioned above, that the first point of the bottom of the cooking vessel has a temperature of approximately 100 ° C., the measuring coil, which has either already been determined beforehand or is only determined thereby, does not immediately come out of the heating mode is taken, because then the total heating output at the hotplate would be unnecessarily reduced. By continuing to heat all induction heating coils, especially the measuring coil, since it can be assumed that the water in the cooking vessel has not yet reached 100 ° C, the heating is continued with the maximum possible output for rapid heating. Only after a certain time will the measuring coil be operated in measuring mode, since only then can it be expected that the 100 ° C in the entire water will soon be reached. This time can also be varied depending on how much water needs to be brought to the boil or how large the cooking vessel is. For this purpose, for example, the previous duration can be used as a criterion when the first induction heating coil detects the temperature gradient that has become zero.
In einer anderen Ausgestaltung der Erfindung kann nicht die erste Induktionsheizspule herangezogen werden, sondern die letzte Induktionsheizspule, deren Temperaturgradient zu Null wird. Auch dann kann wiederum selbst die Messspule noch für eine bestimmte Zeit weiter im Heizbetrieb betrieben werden, da selbst in diesem Fall, dass überall der Kochgefäßboden 100°C beträgt, sehr wahrscheinlich noch nicht das gesamte Wasser im Kochgefäß 100°C aufweist. Diese Zeit für den Weiterbetrieb der Messspule im Heizbetrieb sollte deutlich kürzer als 1 Minute sein und kann insbesondere kürzer als die zuvor genannte Zeit, beispielsweise 5 Sekunden bis 20 Sekunden betragen. Auch hier wird wiederum erst nach Ablauf dieser Zeit die Messspule im Messbetrieb betrieben, wobei sie auch hier wiederum entweder bereits zu Beginn des Heizbetriebs oder erst später zur Messspule bestimmt worden sein kann.In another embodiment of the invention, it is not the first induction heating coil that can be used, but the last induction heating coil, the temperature gradient of which becomes zero. Even then, even the measuring coil can continue to be operated in heating mode for a certain time, since even in this case the bottom of the cooking vessel is everywhere 100 ° C, most likely not all of the water in the cooking vessel is 100 ° C. This time for the continued operation of the measuring coil in heating mode should be significantly shorter than 1 minute and can in particular be shorter than the previously mentioned time, for example 5 seconds to 20 seconds. Here too, the measuring coil is only operated in measuring mode after this time has elapsed, although again it may either have been determined as the measuring coil either at the beginning of the heating mode or only later.
Es ist vorteilhaft möglich, wenn an der Messspule deren Leistung deutlich reduziert worden ist bzw. sie nur noch als Messspule mit der Mess-Leistung betrieben wird, den zeitlichen Verlauf der Wassertemperatur des Wassers im Kochgefäß gleichzusetzen mit dem zeitlichen Verlauf der Periodendauer der Schwingungsantwort an der Messspule, zumindest was den relativen Verlauf betrifft. Diese Messspule arbeitet dann nämlich als Temperatursensor für den über ihr liegenden Bereich des Kochgefäßbodens, der wiederum die Temperatur des an ihn durch Verwirbelung herangeführten Wassers im Kochgefäß bestimmt. Dieser Bereich des Kochgefäßbodens arbeitet dann sozusagen als ein erster Teil eines Sensors. Als zweiter Teil dieses Sensors arbeitet die Messspule, die sozusagen die Temperatur dieses ersten Teils abfragt.It is advantageously possible, if the power of the measuring coil has been significantly reduced or if it is only operated as a measuring coil with the measuring power, to equate the time course of the water temperature of the water in the cooking vessel with the time course of the period of the vibration response at the Measuring coil, at least as far as the relative course is concerned. This measuring coil then works as a temperature sensor for the region of the cooking vessel base lying above it, which in turn determines the temperature of the water in the cooking vessel brought to it by swirling. This area of the bottom of the cooking vessel then works, so to speak, as a first part of a sensor. The second part of this sensor is the measuring coil, which queries the temperature of this first part, so to speak.
Der Messbetrieb der Messspule sollte vorteilhaft so sein, dass sie keine zusätzliche Heizleistung in den über ihr liegenden Bereich des Kochgefäßbodens einbringt, um Verfälschungen bei der Temperaturerfassung bzw. Temperaturbestimmung zu reduzieren oder möglichst ganz zu vermeiden. Wie zuvor kurz erwähnt worden ist, kann hier bereits eine Halbwelle für den Leistungseintrag ausreichen, was dann auch wiederum nur mit einer vorgenannten geringen Leistung bzw. Mess-Leistung gemacht wird.The measuring operation of the measuring coil should advantageously be such that it does not bring any additional heating power into the area of the cooking vessel bottom above it, in order to reduce falsifications in temperature detection or temperature determination or to avoid them as far as possible. As has been mentioned briefly above, a half-wave can already suffice for the power input, which in turn is then only carried out with the aforementioned low power or measuring power.
Es ist möglich, nach dem Erkennen des Kochens des Wassers im Kochgefäß die Leistung der Induktionsheizspulen bzw. der Kochstelle zu reduzieren, um ein Überkochen des Wassers zu verhindern. Dies kann um mindestens 10% bis 20% erfolgen, vorteilhaft sogar um mindestens 50% bis 70%.It is possible to reduce the power of the induction heating coils or the hotplate after the water has boiled in the cooking vessel in order to prevent the water from boiling over. This can be done by at least 10% to 20%, advantageously even by at least 50% to 70%.
Ausführungsbeispiele der Erfindung sind in den Zeichnungen schematisch dargestellt und werden im Folgenden näher erläutert. In den Zeichnungen zeigen:
- Fig.1
- eine schematische Ansicht einer Anordnung mehrerer Induktionsheizspulen eines Induktionskochfelds mit aufgestelltem Kochgefäß,
- Fig. 2
- eine schematische Seitenansicht einer Beheizung des Kochgefäßes aus
Fig. 1 mit den darunter befindlichen Induktionsheizspulen, wobei zwei Induktionsheizspulen im Heizbetrieb arbeiten samt entstehender Wasserströmungen, - Fig. 3
- eine Abwandlung der Darstellung aus
Fig. 2 , wobei eine Induktionsheizspule im Heizbetrieb und eine im Messbetrieb arbeitet samt entstehender Wasserströmungen und - Fig. 4
- eine Darstellung von Verläufen sowohl der Wassertemperatur an zwei Stellen im Kochgefäß als auch von Signalen einer Induktionsheizspule im Heizbetrieb einerseits und einer im Messbetrieb andererseits.
- Fig. 1
- 1 shows a schematic view of an arrangement of a plurality of induction heating coils of an induction hob with the cooking vessel set up,
- Fig. 2
- a schematic side view of a heating of the cooking vessel
Fig. 1 with the induction heating coils underneath, whereby two induction heating coils work in heating mode with the resulting water flows, - Fig. 3
- a modification of the presentation
Fig. 2 , where an induction heating coil works in heating mode and one in measuring mode including water flows and - Fig. 4
- a representation of profiles both of the water temperature at two points in the cooking vessel and of signals from an induction heating coil in heating mode on the one hand and one in measuring mode on the other.
In der
In der Seitenansicht der
Die Induktionsheizspulen 13a und 13b sind mit einer Steuerung 19 des Induktionskochfelds 11 verbunden und werden über diese angesteuert mit Leistung versorgt, üblicherweise über ein hier nicht dargestelltes Leistungsteil bzw. entsprechende Schwingkreisanordnungen.The
Mit dünnen Pfeilen dargestellt ist jeweils ein Leistungseintrag 21a und 21b von jeder der Induktionsheizspulen 13a und 13b in das Kochgefäß 15 bzw. in den Kochgefäßboden 16. Dies ist dem Fachmann bekannt und darauf muss nicht näher eingegangen werden. Wie zuvor erwähnt, beträgt die Eindringtiefe des Leistungseintrags 21 weniger als 2mm, vorteilhaft weniger als 1mm. Von dieser untersten Schicht des Kochgefäßbodens 16 verteilt sich die entstehende Wärme nach oben durch den weiteren Aufbau des Kochgefäßbodens 16 hindurch, unter Umständen mit einer entsprechenden Querverteilung. An der Oberseite des Kochgefäßbodens 16 erfolgt der Wärmeübergang in darüber im Kochgefäß 15 befindliches Wasser 17. Durch die eingebrachte Wärme steigt dieses aufgewärmte Wasser auf, was durch die breiten Pfeile veranschaulicht ist. Selbstverständlich erfolgt eine Art Durchmischung der Wasserströmungen 23a und 23b, hier auch noch dargestellt durch weitere Wasserströmungen 23.The thin arrows show a
In
Mit dicker gestrichelter Linie ist die Temperatur des Wassers über der linken Induktionsheizspule 21a nahe dem Kochgefäßboden 16 dargestellt. Hier wird das Wasser 17 wohl am heißesten sein und am schnellsten kochen. Außerdem ist für die Temperatur des Wassers 17 der Wert von 100°C eingezeichnet. Bei den Wassertemperaturen mit dicken Linien sind die Verlaufshöhen relativ zueinander in etwa maßstäblich.The temperature of the water above the left
Mit dünner durchgezogener Linie ist der eingangs genannte Messwert bzw. das Periodensignal derjenigen Induktionsheizspule 13b dargestellt, die als Messspule im Messbetrieb verwendet wird. Mit gestrichelter dünner Linie ist das Periodensignal der im Heizbetrieb betriebenen Induktionsheizspule 13a dargestellt. Diese beiden Periodensignale müssen absolut gesehen nicht unterschiedlich groß sein, dies ist hier nur der Übersichtlichkeit halber dargestellt, um ihre relativen Verläufe besser zu zeigen. Insbesondere können sie vor allem am Anfang weitgehend deckungsgleich sein.The measured value or the period signal of the
Zur Durchführung des erfindungsgemäßen Verfahrens wird nach dem Aufsetzen des Kochgefäßes 15 auf das Induktionskochfeld 11 bzw. über die Induktionsheizspulen 13 von der Steuerung 19 auf bekannte Art und Weise erfasst, welche Induktionsheizspulen überhaupt überdeckt sind und in wie stark bzw. mit welchem Überdeckungsgrad. Bei den Induktionsheizspulen 13 der Konfiguration der
Gemäß einer ersten Variante des Verfahrens kann nun die Induktionsheizspule 13b als Messspule bestimmt werden, da sie den erkennbar geringsten Überdeckungsgrad durch das Kochgefäß 15 bzw. den Kochgefäßboden 16 aufweist. Diese Bestimmung kann erfolgen, selbst wenn auch die Messspule 13b mit den anderen zusammen noch im Heizbetrieb als Kochstelle betrieben wird. Alternativ kann das in
Im hier beschriebenen Ausführungsbeispiel gilt dieser Fall, dass die Steigung als letzte zu Null geworden ist, für die Induktionsheizspule 13b. Das bedeutet, dass über allen anderen Induktionsheizspulen 13 der Kochstelle die Temperatur höher ist bzw. früher schon hoch war.In the exemplary embodiment described here, this case applies that the slope has become the last to be zero for the
Gleichzeitig ist aus der
Die nun im Messbetrieb als Messspule mit der Mess-Leistung betriebene Induktionsheizspule 13b weist den durchgezogenen Verlauf mit der dünnen Linie auf. Die Mess-Leistung beträgt beispielsweise 5% der maximalen Leistung. Der Verlauf des Periodensignals an der Messspule 13b zeigt auch, dass nach dem Wechsel in den Messbetrieb ja diese Messspule nahezu keine Energie mehr in den Kochgefäßboden überträgt und diesen somit nicht weiter aufzuheizen versucht. Da das in dem Kochgefäß 15 befindliche Wasser 17 insgesamt noch keine 100°C hat, also noch nicht insgesamt kocht, sondern beispielsweise nur 80°C bis 90°C aufweist, fällt dieses relativ kühlere Wasser wieder auf diesen Bereich des Kochgefäßbodens herunter und kühlt ihn auf weniger als 100°C ab. Er wird also im Vergleich zu dem vorherigen Heizbetrieb der Messspule 13b gekühlt. Dies ist zu erkennen an dem dargestellten Abfall des Periodensignals der Messspule. Nach einer gewissen Zeit, beispielsweise 10 Sekunden bis 30 Sekunden, weist dieser Bereich des Kochgefäßbodens die Temperatur des relativ kühleren herabströmenden Wassers auf, so dass auch das Periodensignal der Messspule quasi gleich verläuft wie die Wassertemperatur. Dies ist der Verständlichkeit halber hier gemeinsam bzw. in Überdeckung dargestellt, muss aber nicht so sein.The
Gleichzeitig ist zu sehen, wie die gestrichelt dargestellte Temperatur des Wassers beispielsweise über der weiterhin im Heizbetrieb betriebenen Induktionsheizspule 13a gemäß
Die Zustände im Kochgefäß 15 in diesem Zeitraum sind in
Nach einiger Zeit dann hat durch den fortwährenden Leistungseintrag der übrigen drei Induktionsheizspulen, der vorteilhaft mit gleicher bzw. maximaler Leistung erfolgt, die gesamte bzw. gemittelte Temperatur des gesamten Wassers etwa 100°C erreicht, insbesondere nach ausreichender Durchmischung des vom Kochgefäßboden 16 über den Heizspulen aufgeheizten Wassers mit dem restlichen Wasser. Wenn dann in
Bei den mit dicken Pfeilen dargestellten Wasserströmungen 23a und 23b in der
Anhand der Beschreibung zu den
Claims (10)
- Method for temperature determination in an induction hob (11) comprising a plurality of induction heating coils (13), wherein the induction heating coils (13) can be individually driven and, in a common heating mode, form a cooking point for a cooking vessel (15) containing water,
characterized in that the method comprises the following steps:- a cooking vessel (15) containing water is positioned such that it covers at least two induction heating coils (13) by way of a cooking vessel base (16),- the induction heating coils (13) are operated in the heating mode in order to bring the water (17) in the cooking vessel (15) to boil, which is to be detected as temperature determination,- during the heating mode, each induction heating coil (13) heats that region of the cooking vessel base (16) which is arranged above it,- during the heating mode, the oscillation response on at least one induction heating coil (13) is used to detect whether the temperature of the region of the cooking vessel base (16) above this induction heating coil (13) changes or increases,- the induction heating coils (13) are operated in the heating mode at least until one induction heating coil (13) detects that the temperature gradient of the cooking vessel base (16) above this induction heating coil is approaching zero or has reached zero,- at least one of the induction heating coils (13) is determined to be a measuring coil,- the measuring coil is operated in the measuring mode and no longer in the heating mode, wherein the measuring coil, in the measuring mode with a measuring power of up to a maximum of 50% of the maximum power, transmits energy into the cooking vessel base (16) for a short time and then detects the fed-back oscillation response, wherein the time profile of this oscillation response is evaluated after several coupling-in operations of the measuring power, wherein then, in case that the gradient of this time profile is approaching zero or has reached zero, the water (17) in the cooking vessel (15) is determined to be boiling. - Method according to claim 1, characterized in that that induction heating coil (13) which first has a temperature gradient which reaches zero during the heating mode is determined to be a measuring coil.
- Method according to claim 1, characterized in that that induction heating coil (13) which has the lowest power input into the cooking vessel (15) and/or the lowest degree of coverage by the cooking vessel is determined to be a measuring coil.
- Method according to any of the preceding claims, characterized in that all of the induction heating coils (13) are operated in the heating mode at least until the temperature gradient of the cooking vessel base (16) which is located above each of the induction heating coils has reached zero.
- Method according to any of the preceding claims, characterized in that the measuring coil transmits energy into the cooking vessel base (16) in the measuring mode with the measuring power for half a cycle, and then detects the fed-back oscillation response.
- Method according to any of the preceding claims, characterized in that, after the first induction heating coil (13) has or detects a temperature gradient which has reached zero, the heating mode of all of the induction heating coils (13), which operate in the heating mode for this cooking vessel (15), is continued for at least 10 seconds, preferably for at least 30 seconds, at a constant power, wherein the previously determined measuring coil is operated in the measuring mode after this time has elapsed.
- Method according to any of the claims 1 to 5, characterized in that, after all of the induction heating coils (13) of the cooking point have or have detected a temperature gradient which has reached zero, the heating mode of all of the induction heating coils (13), which operate in the heating mode for this cooking vessel (15), is continued for at least 10 seconds, preferably for at least 30 seconds, at a constant power.
- Method according to any of the preceding claims, characterized in that, on the basis of values which are stored in a memory, for the level of the total added power input of all of the induction heating coils (13), which are operated jointly as a cooking point in the heating mode for a cooking vessel (15), into the cooking vessel and, on the basis of the time until the temperature gradient of the first induction heating coil or the temperature gradient of the last induction heating coil has reached zero, the time for which the heating mode is continued, after the temperature gradient of the first induction heating coil or the last induction heating coil has reached zero up to the time at which one of the induction heating coils is operated as a measuring coil, is determined.
- Method according to any of the preceding claims, characterized in that, after the considerable reduction in the power at the measuring coil (13) during the temperature determination by the measuring coil, the profile of the water temperature of water (17) in the cooking vessel (15) is set equal to the profile of the cycle duration at the measuring coil.
- Method according to any of the preceding claims, characterized in that, after it is identified that the water (17) in the cooking vessel (15) is boiling, the power of the induction heating coils (13) or of the cooking point is reduced, in particular by at least 50%, in order to prevent the water from boiling over.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PL16184674T PL3136822T3 (en) | 2015-08-27 | 2016-08-18 | Method for determining a temperature |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102015216455.1A DE102015216455A1 (en) | 2015-08-27 | 2015-08-27 | Method for temperature determination |
Publications (2)
Publication Number | Publication Date |
---|---|
EP3136822A1 EP3136822A1 (en) | 2017-03-01 |
EP3136822B1 true EP3136822B1 (en) | 2020-04-29 |
Family
ID=56738019
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP16184674.6A Active EP3136822B1 (en) | 2015-08-27 | 2016-08-18 | Method for determining a temperature |
Country Status (6)
Country | Link |
---|---|
US (1) | US10219327B2 (en) |
EP (1) | EP3136822B1 (en) |
CN (1) | CN106488601B (en) |
DE (1) | DE102015216455A1 (en) |
ES (1) | ES2804108T3 (en) |
PL (1) | PL3136822T3 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106802584A (en) * | 2017-03-22 | 2017-06-06 | 广东美的厨房电器制造有限公司 | Cooking methods, cooker and cooking apparatus |
EP3714747B1 (en) * | 2019-03-29 | 2024-02-21 | Vorwerk & Co. Interholding GmbH | Kitchen appliance with boiling point monitoring |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102011083397A1 (en) * | 2011-09-26 | 2013-03-28 | E.G.O. Elektro-Gerätebau GmbH | Method for preparing food by means of an induction heating device and induction heating device |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19540408A1 (en) | 1995-10-30 | 1997-05-07 | Herchenbach Wolfgang | Cooking system |
DE10314690A1 (en) | 2003-03-27 | 2004-10-07 | E.G.O. Elektro-Gerätebau GmbH | Heating device for flat heating with induction heating elements |
JP4381875B2 (en) * | 2004-04-21 | 2009-12-09 | パナソニック株式会社 | Induction heating cooker |
WO2006032292A1 (en) * | 2004-09-23 | 2006-03-30 | E.G.O. Elektro-Gerätebau GmbH | Heating device for a planar heater with induction heating elements |
FR2903564B1 (en) * | 2006-07-06 | 2011-07-01 | Seb Sa | COOKING PLATE FOR DETECTING THE TEMPERATURE OF A CULINARY ARTICLE |
DE102009047185B4 (en) * | 2009-11-26 | 2012-10-31 | E.G.O. Elektro-Gerätebau GmbH | Method and induction heating device for determining a temperature of a cooking vessel bottom heated by means of an induction heating coil |
CH704318B1 (en) | 2011-01-07 | 2016-03-15 | Inducs Ag | Induction cooking device for temperature-controlled cooking. |
CH704364B1 (en) * | 2011-01-14 | 2015-01-30 | Inducs Ag | Modular Warming System for Food. |
DE102011083383A1 (en) * | 2011-09-26 | 2013-03-28 | E.G.O. Elektro-Gerätebau GmbH | Method for heating a liquid contained in a cooking vessel and induction heating device |
US9699834B2 (en) | 2012-10-22 | 2017-07-04 | Panasonic Intellectual Property Management Co., Ltd. | Induction heating cooker |
EP2779787B1 (en) * | 2013-03-11 | 2015-06-17 | Electrolux Appliances Aktiebolag | Method of detecting cookware on an induction hob, induction hob and cooking appliance |
-
2015
- 2015-08-27 DE DE102015216455.1A patent/DE102015216455A1/en not_active Withdrawn
-
2016
- 2016-08-18 EP EP16184674.6A patent/EP3136822B1/en active Active
- 2016-08-18 PL PL16184674T patent/PL3136822T3/en unknown
- 2016-08-18 ES ES16184674T patent/ES2804108T3/en active Active
- 2016-08-25 US US15/246,646 patent/US10219327B2/en active Active
- 2016-08-26 CN CN201610730744.8A patent/CN106488601B/en active Active
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102011083397A1 (en) * | 2011-09-26 | 2013-03-28 | E.G.O. Elektro-Gerätebau GmbH | Method for preparing food by means of an induction heating device and induction heating device |
Also Published As
Publication number | Publication date |
---|---|
CN106488601B (en) | 2020-10-27 |
PL3136822T3 (en) | 2020-11-02 |
EP3136822A1 (en) | 2017-03-01 |
CN106488601A (en) | 2017-03-08 |
DE102015216455A1 (en) | 2017-03-02 |
ES2804108T3 (en) | 2021-02-03 |
US20170064776A1 (en) | 2017-03-02 |
US10219327B2 (en) | 2019-02-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP3267113B1 (en) | Method for operating a cooking hob | |
EP2087770B1 (en) | Method for controlling an induction cooking appliance and induction cooking appliance | |
EP3177107B1 (en) | Method for operating an induction cooking hob | |
EP2574144B1 (en) | Method for heating a cooking vessel using an induction heating device and induction heating device | |
DE102004003126B4 (en) | Driving method for heating elements and device | |
EP1732357A2 (en) | Heating device for induction cooking devices | |
EP2574143B1 (en) | Method for heating a liquid contained in a cooking vessel and induction heating device | |
EP2574145B1 (en) | Method for preparing food by means of an induction heating device and induction heating device | |
DE19648397A1 (en) | Method and device for recognizing the cooking point of food | |
EP3307018B1 (en) | Method for controlling an induction hob and induction hob | |
EP3136822B1 (en) | Method for determining a temperature | |
DE102005003672A1 (en) | High-frequency pulse oscillator | |
DE3642180C2 (en) | ||
DE10122427A1 (en) | Method and device for limiting and / or controlling the surface temperature of a hob | |
DE102015201079A1 (en) | Method for controlling the temperature of a hob | |
EP0806887B1 (en) | Method and device for recognizing the stage of cooking of cooked food | |
EP2506673B1 (en) | Induction cooktop | |
EP3307019B1 (en) | Method for the operation of an induction hob and induction hob | |
DE19714701B4 (en) | Regulated inductive heating system | |
DE102016222313B4 (en) | Method of cooking at least one egg | |
EP3606284B1 (en) | Method and device for inductive energy transfer | |
EP1492385A2 (en) | Method and device of determination of heating processus | |
DE69108069T2 (en) | Method and device for determining the weight of food in a microwave oven and for controlling its treatment. | |
DE102004016631A1 (en) | A method for controlling the temperature of a cooking vessel on a cooker hob unit has a ring of four capacitive sensors around the perimeter of the heating unit | |
DE102004033115A1 (en) | A method for controlling the temperature of a cooker heating system has an inductive temperature variable coil heating element and control system monitoring the specific resonant frequency |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
AX | Request for extension of the european patent |
Extension state: BA ME |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE |
|
17P | Request for examination filed |
Effective date: 20170720 |
|
RBV | Designated contracting states (corrected) |
Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: GRANT OF PATENT IS INTENDED |
|
RIC1 | Information provided on ipc code assigned before grant |
Ipc: H05B 6/06 20060101AFI20191112BHEP |
|
INTG | Intention to grant announced |
Effective date: 20191203 |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE PATENT HAS BEEN GRANTED |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D Free format text: NOT ENGLISH |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R096 Ref document number: 502016009727 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: REF Ref document number: 1265285 Country of ref document: AT Kind code of ref document: T Effective date: 20200515 |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D Free format text: LANGUAGE OF EP DOCUMENT: GERMAN |
|
REG | Reference to a national code |
Ref country code: NL Ref legal event code: MP Effective date: 20200429 |
|
REG | Reference to a national code |
Ref country code: LT Ref legal event code: MG4D |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 Ref country code: NO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200729 Ref country code: SE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 Ref country code: FI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200730 Ref country code: PT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200831 Ref country code: IS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200829 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: HR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 Ref country code: RS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 Ref country code: LV Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 Ref country code: BG Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200729 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 Ref country code: AL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CZ Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 Ref country code: RO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 Ref country code: SM Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 Ref country code: EE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R097 Ref document number: 502016009727 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FG2A Ref document number: 2804108 Country of ref document: ES Kind code of ref document: T3 Effective date: 20210203 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MC Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
26N | No opposition filed |
Effective date: 20210201 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200831 Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200818 Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200831 |
|
REG | Reference to a national code |
Ref country code: BE Ref legal event code: MM Effective date: 20200831 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200818 Ref country code: BE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200831 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 Ref country code: CY Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200429 |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: MM01 Ref document number: 1265285 Country of ref document: AT Kind code of ref document: T Effective date: 20210818 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: AT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20210818 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: TR Payment date: 20230811 Year of fee payment: 8 Ref country code: IT Payment date: 20230831 Year of fee payment: 8 Ref country code: GB Payment date: 20230824 Year of fee payment: 8 Ref country code: ES Payment date: 20230918 Year of fee payment: 8 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: PL Payment date: 20230807 Year of fee payment: 8 Ref country code: FR Payment date: 20230821 Year of fee payment: 8 Ref country code: DE Payment date: 20230822 Year of fee payment: 8 |