Abstract
A heating module includes at least one cold conductor element and at least one electrical heating element that is different from the at least one cold conductor element. The at least one cold conductor element and the at least one heating element are electrically connectable in parallel. The at least one cold conductor element and the at least one heating element are connected with one another thermally in a heat-transferring manner.
Claims
1. A heating module, comprising: at least one cold conductor element and at least one electrical heating element that is different from the at least one cold conductor element, the at least one cold conductor element and the at least one heating element are electrically connectable in parallel, and the at least one cold conductor element and the at least one heating element are connected with one another thermally in a heat-transferring manner.
2. The heating module according to claim 1, wherein: a maximum operating temperature is predetermined, and the at least one cold conductor element is configured such that the maximum operating temperature lies above a starting temperature of the at least one cold conductor element.
3. The heating module according to claim 2, wherein the at least one cold conductor element is configured such that the maximum operating temperature is equal to or greater than an end temperature of the at least one cold conductor element.
4. The heating module according to claim 1, wherein an electrical resistance of the at least one heating element and a nominal resistance of the at least one cold conductor element are in a ratio of between 95:5 to 5:95.
5. The heating module according to claim 4, wherein the electrical resistance of the at least one heating element and the nominal resistance of the at least one cold conductor element are in a ratio of between 30:70 to 70:30.
6. The heating module according to claim 1, further comprising at least one heat transfer body, separate from the at least one cold conductor element and from the at least one heating element, wherein the at least one heat transfer body is connected in a planar, heat-transferring manner with the at least one cold conductor element and the at least one heating element and connects the at least one cold conductor element and the at least one heating element thermally with one another.
7. The heating module according to claim 6, wherein the at least one heat transfer body is structured as a plate.
8. The heating module according to claim 6, wherein the at least one heat transfer body is a ceramic.
9. The heating module according to claim 1, wherein: the at least one cold conductor element and the at least one heating element are arranged adjacent to one another in a neighbour direction, further including at least one electrically insulating plate arranged transversely to the neighbour direction adjacent at least to the at least one cold conductor element and the at least one heating element, and connects the at least one cold conductor element and the at least one heating element with one another thermally in a heat-transferring manner.
10. The heating module according to claim 1, wherein: the heating module has a maximum total heating output, the at least one cold conductor element is configured such that a maximum cold conductor heating output of the at least one cold conductor element corresponds to between 80% and 95% of the maximum total heating output, and the at least one heating element is configured such that a maximum heating element heating output of the at least one heating element corresponds at least to the difference between the maximum total heating output and the maximum cold conductor heating output.
11. A heating device, comprising: a heating module, the heating module including: at least one cold conductor element and at least one electrical heating element that is different from the at least one cold conductor element, the at least one cold conductor element and the at least one heating element are electrically connectable in parallel, the at least one cold conductor element and the at least one heating element are connected with one another thermally in a heat-transferring manner, a switching device configured such that, in operation, it respectively produces and disconnects an electrical supply at least of the at least one cold conductor element and the at least one heating element, a determining device configured such that, in operation, it determines at least one value characterizing a temperature of at least one of the at least one cold conductor element and the at least one heating element, and a control device connected with the switching device and with the determining device in a communicating manner and configured for operating the heating device.
12. The heating device according to claim 11, wherein the control device is configured such that, in a starting operation where the temperature of the at least one cold conductor element lies below a starting temperature of the at least one cold conductor element, the control device operates the heating device as follows: the electrical supply of the at least one cold conductor element is interrupted and the at least one heating element is supplied electrically, so that the at least one heating element generates heat, and the at least one cold conductor element is supplied electrically, when the at least one value corresponds to a temperature of the at least one cold conductor element that is greater than or equal to the starting temperature of the at least one cold conductor element.
13. The heating device according to claim 12, wherein the control device is configured such that it furthermore operates the heating device in the starting operation as follows: the electrical supply of the at least one heating element is interrupted when the at least one value corresponds to a temperature of the at least one cold conductor element that is greater than or equal to the starting temperature.
14. The heating device according to claim 11, wherein the control device is configured such that, in a first regular operation where the temperature of the at least one cold conductor element lies above the starting temperature of the at least one cold conductor element, the control device operates the heating device as follows: the at least one value characterizing the temperature of the at least one of the at least one cold conducting element and the at least one heating element is monitored, and an electrical output that is fed to the at least one heating element is reduced when the at least one value corresponds to a predetermined maximum operating temperature of the heating module.
15. The heating device according to claim 13, wherein the control device is configured such that, in a second regular operation where the temperature of the at least one cold conductor element lies above the starting temperature of the at least one cold conductor element, the control device operates the heating device as follows: when a required total heating output is less than or equal to a maximum cold conductor heating output, exclusively the at least one cold conductor element is supplied electrically, and when a required total heating capacity rises above the maximum cold conductor heating output, in addition the at least one heating element is supplied electrically.
16. The heating device according to claim 11, wherein the determining device is configured such that it determines, as the at least one value, the temperature of the at least one of the at least one cold conductor element and the at least one heating element.
17. The heating device according to claim 11, wherein the determining device is configured such that it determines, as the at least one value, an electrical resistance of the at least one cold conductor element.
18. The heating device according to claim 11, wherein the determining device is configured such that it determines, as the at least one value, a heating output of the heating module.
19. The heating device according to claim 11, further comprising a flow path of a fluid that leads through the heating device, and the heating module is connected with the flow path in a heat-transferring manner.
20. The heating device according to claim 11, wherein an electrical resistance of the at least one heating element and a nominal resistance of the at least one cold conductor element are in a ratio of between 95:5 to 5:95.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0057] There are shown, respectively schematically
[0058] FIG. 1 a characteristic curve of a cold conductor element.
[0059] FIG. 2 a first section through a heating module,
[0060] FIG. 3 a second section through the heating module,
[0061] FIG. 4 an equivalent circuit diagram of the heating module,
[0062] FIG. 5 an equivalent circuit diagram of a heating device with the heating module,
[0063] FIGS. 6 to 8 different sections through the heating module in another example embodiment,
[0064] FIGS. 9 to 11 different sections through the heating module in a further example embodiment,
[0065] FIG. 12 a highly simplified sectional view of the heating device,
[0066] FIG. 13 a section through the heating device in another example embodiment,
[0067] FIG. 14 the view of FIG. 13 in a further example embodiment.
DETAILED DESCRIPTION
[0068] FIG. 1 shows a characteristic curve 1 of a cold conductor element 2, as is shown for example in FIGS. 2 to 14. The cold conductor element 2, also designated Positive Temperature Coefficient element 2 or abbreviated as PTC element 2, has according to FIG. 1 a temperature-dependent electrical resistance. Here in FIG. 1 the temperature is entered on the abscissa axis 3, and the electrical resistance is entered on the coordinate axis 4 on logarithmic scale. Accordingly, the electrical resistance of the cold conductor element 2 initially falls with increasing temperature, until at a starting temperature 5 a minimum resistance 6 of the cold conductor element 2 is reached. The temperature range up to the starting temperature 5 of the cold conductor 2 is designated as Negative Temperature Coefficient range 7, also abbreviated as NTC range 7 below. At temperatures above the starting temperature 5, the electrical resistance rises intensively up to a nominal temperature 8, at which the cold conductor element 2 has a nominal resistance 9. A less marked rise of the electrical resistance between the nominal temperature 8 and an end temperature 10, at which the cold conductor element 2 has an end resistance 11, follows the more intensive rise of the electrical resistance between the starting temperature 5 and the nominal temperature 8. Starting from the end temperature 10, the characteristic of the resistance changes, wherein the end temperature 10 or respectively the end resistance 11 forms a turning point of the curve 1. The range above the starting temperature 5 is designated here as Positive Temperature Coefficient range 12, also abbreviated below as PTC range 12. The temperature range between the starting temperature 5 and the end temperature 10 is regarded as working range 13 of the cold conductor element 2. The starting resistance 6 or respectively the starting temperature 5 are regarded as the switching point. This means that the resistance falls up to the turning point or respectively up to the starting temperature 5 or respectively, in so far as the cold conductor element 2 is connected to a voltage source, the electrical current increases through the cold conductor element 2, wherein owing to capacities and inductivities of the cold conductor element 2 in the switching point or respectively at the starting temperature 5 or the starting resistance 6, peaks occur in the electrical current and in the voltage.
[0069] A heating module 14 according to the invention, as is shown in FIGS. 2 to 7, prevents or reduces said current peaks and/or voltage peaks. For this purpose, the heating module 14 has, in addition to the cold conductor element 2, an electrical heating element 15 which is different from the cold conductor element 2. The heating element 15 therefore in particular does not show a characteristic curve for a cold conductor element 2, as is shown by way of example in FIG. 1. The heating element 15 is, in particular, free of a cold conductor element 2. The cold conductor element 2 and the heating element 15 are electrically connected in parallel here or are connected with one another in such a way that they are able to be electrically connected in parallel.
[0070] The cold conductor element 2 and the heating element 15 are connected with one another in a thermally heat-transferring manner, in such a way that the temperature of the cold conductor element 2 corresponds substantially to the temperature of the heating element 15. In the example embodiments which are shown, the heat-transferring connection of the cold conductor element 2 with the heating element 15 takes place via at least one heat transfer body 16 which is separate from the cold conductor element 2 and from the heating element 15. In the example embodiments which are shown, respectively two such heat transfer bodies 16 are provided, between which the heating element 15 and the cold conductor element 2 are arranged. The heat transfer bodies 16 which are shown are respectively formed in a plate-shaped manner or respectively as a plate 17. In addition, in the example embodiments which are shown, the heat transfer bodies 16 are electrically insulating. In particular, the heat transfer bodies 16 are formed as a ceramic 18, for example as a ceramic plate 19. The heat transfer bodies 16 therefore connect the cold conductor element 2 in a heat-transferring manner with the heating element 15 and electrically insulate the cold conductor element 2 and the heating element 15 toward the exterior. Here, in the examples which are shown, the cold conductor element 2 and the heating element 15 are arranged adjacent to one another in a direction 20, also designated below as neighbour direction 20, wherein the respective heat transfer body 16 is adjacent to the cold conductor element 2 and to the heating element 15 transversely to the neighbour direction 20. Here, in the example embodiments which are shown, the respective heat transfer body 16 lies in a planar manner against the cold conductor element 2 and against the heating element 15. In the example embodiments which are shown, the heating module 14 is therefore formed in the manner of a rod 30, also designated below as heating rod 30.
[0071] In the example embodiments which are shown, the respective cold conductor element 2 is parallelepiped-shaped and is formed in the manner of a block. In particular the respective cold conductor element 2 is formed as a so-called cold conductor block 21, also designated below as PTC block 21.
[0072] In the example embodiments of FIGS. 2 and 3, the respective heating element 15 is formed purely by way of example as a web-like resistance heater 23. However, the heating element 15 can also be formed as a thick film heater 22, as shown in the example embodiments of FIGS. 6 to 14.
[0073] The example embodiments of the heating module 14 which are shown provide respectively purely by way of example two or more cold conductor elements 2 per heating module 14.
[0074] FIGS. 2 and 3 show a first example embodiment of the heating module 14, wherein FIG. 2 shows a section through the heating module 14 along the neighbour direction 20, and FIG. 3 shows a section through the in FIG. 2 one plane funning transversely to the section plane of FIG. 2, in such a way that only one of the heat transfer bodies 16 is visible. Accordingly, the heating module 14 of FIGS. 2 and 3 has four cold conductor elements 2, which are arranged adjacent to one another in neighbour direction 20. The cold conductor elements 2 are advantageously formed identically. In neighbour direction 20, the heating element 15 follows the cold conductor elements 2. As can be seen from FIGS. 2 and 3, the neighbour direction 20 runs parallel to a longitudinal direction 25 and transversely to a transverse direction 24 of the heating module 14. As can be seen in particular from FIG. 3, the heating module 14 has, furthermore, four electrical connections 26. Two of the electrical connections 26, designated below as first electrical connection 26′ and second electrical connection 26″, are connected via at least one electrical line 29 with the cold conductor elements 2 in such a way that the cold conductor elements 2 are connected in series via the at least one line 29. The two other electrical connections 26, designated below as third electrical connection 26′″ and fourth electrical connection 26″″, are electrically connected with the heating element 15 via two electrical lines 29 for the electrical supply of the heating element 15. The cold conductor elements 2 on the one hand and the heating element 15 on the other hand are able to be electrically connected in parallel via the electrical connections 26.
[0075] FIG. 4 shows an equivalent circuit diagram of the heating module 14, wherein in the equivalent circuit diagram 27 the cold conductor elements 2 are combined to a common cold conductor element 2. It can be seen from FIG. 4 that the cold conductor elements 2 and the heating element 15 are electrically connected in parallel. In FIG. 4 furthermore an equivalent resistance 28 of the electrical lines 29 is taken into consideration.
[0076] The heating module 14 is used in a heating device 31, the equivalent circuit diagram 27 of which is illustrated in FIG. 5 and which is illustrated by way of example in FIGS. 12 to 14.
[0077] FIG. 12 shows here a highly simplified illustration of the heating device 31 in section. As can be seen in particular from FIG. 12, the heating device 31 can serve for heating a fluid. For this purpose, a flow path 32 of the fluid, indicated by arrows, leads through the heating device 31. The heating device 31 has furthermore at least one heating module 14, which is connected with the flow path 32 in a heat-transferring manner, so that the heating module 14 heats the fluid in operation. In the example embodiment of FIG. 12, several such heating modules 14 are provided, which are arranged spaced apart with respect to one another. Here, the heating modules 14 are arranged respectively in the flow path 32, in such a way that the flow path 32 runs between the successive heating modules 14. Between the adjacent heating modules 14, as shown by way of example for two of the heating modules 14 in FIG. 12, a structure 33, in particular a rib structure 34 or a grid 38, can be arranged, which is able to be flowed through by the fluid, through which therefore the flow path 32 leads and by which the heat-transferring area as a whole is enlarged. As can be seen furthermore from FIG. 12, the respective heating device 31 can have an inlet 35 for letting in the fluid into the heating device 31, and an outlet 36 for letting out the fluid from the heating device 31. The respective heating device 31 can have, furthermore, a housing 37, in which the heating modules 14 are arranged and through which the flow path 32 leads. In the example embodiment of FIG. 12, for better illustration only one single cold conductor element 2 and the heating element 15 are illustrated. The direct contact between the cold conductor element 2 and the heating element 15 is in addition to symbolise the thermally heat-transferring connection of the heating element 15 with the respective cold conductor element 2. For this reason, the heat transfer bodies 16 are not illustrated in FIG. 12.
[0078] As can be seen from FIG. 5, the heating device 31 has, in addition to the heating module 14 with the heating element 15 and the at least one cold conductor element 2 which according to the equivalent circuit diagram 27 are connected or respectively able to be connected electrically in parallel, a switching device 39 by which the electrical supply of the heating element 15 and of the cold conductor element 2 can be respectively optionally disconnected or produced. In particular, the switching device 39 is configured in such a way that the electrical supply can be varied respectively. In the equivalent circuit diagram 27 of FIG. 5, the switching device 39 is realized by a first switch 40 and a second switch 41. For example, in a heating module 14 according to the example embodiment of FIGS. 2 and 3, the first switch 40 is able to connect the first electrical connection 26′ with the second electrical connection 26″, in order to supply the cold conductor elements 2 electrically and to disconnect this connection in order to interrupt an electrical supply of the cold conductor elements 2. In an analogous manner hereto, the second switch 41 is able to electrically connect the third electrical connection 26′″ with the fourth electrical connection 26″″, in order to supply the heating element 15 electrically and to disconnect this electrical connection in order to interrupt the electrical supply of the heating element 15. The heating device 31 has, in addition, a determining device 42. With the determining device 42, at least one value is determined which characterizes the temperature at least of one of the elements 2, 15, i.e. at least one of the cold conductor elements 2 and/or of the heating element 15. The determining device 42 determines, for this, in particular the temperature at least of one of the elements 2, 15 and/or the electrical resistance at least of one of the cold conductor elements 2 and/or the heating output of the heating module 14. The heating device 31 has, moreover, a control device 43 which, as indicated by dashed lines, is connected with the determining device 42 and with the switching device 39, in particular with the respective switch 40, 41, and serves for operating the heating device 31. Here, the switching device 39, the determining device 42 and the control device 43 are illustrated respectively only in FIG. 5.
[0079] A further example embodiment of the heating module 14 is shown in FIGS. 6 to 8. Here, FIG. 6 shows a section through the heating module 14 along the longitudinal direction 25. FIGS. 7 and 8 show sections through the section plane illustrated in dashed lines in FIG. 6, wherein FIG. 7 shows the section in the direction of one of the heat transfer bodies 16, also designated below as first heat transfer body 16′, and FIG. 8 shows the section in the direction of the other heat transfer body 16, also designated below as second heat transfer body 16″. In this example embodiment, the heating module 14, which is also formed as a heating rod 30, has five cold conductor elements 2 and ten heating elements 15. The heating elements 15 are formed respectively in a web-shaped manner and as a resistance heater 23, wherein also a configuration as a thick film heater 22 is conceivable. The cold conductor elements 2 are arranged spaced apart with respect to one another in longitudinal direction 25 and lie against both heat transfer bodies 16. Between the adjacent cold conductor elements 2, two heating elements 15 are arranged respectively lying opposite, spaced apart with respect to the cold conductor elements 2 and transversely to the longitudinal direction 25 and transversely to the transverse direction 24, wherein one of these heat conductor elements 15 lies in a planar manner against the first heat transfer body 16′, and the opposite heating element 15 lies in a planar manner against the second heat transfer body 16″. Respectively a heating element 15 adjoins the outer cold conductor elements 2 in longitudinal direction 25, spaced apart in longitudinal direction 25 with respect to the outer cold conductor elements 2, wherein one of these heating elements 15 lies in a planar manner against the first heat transfer body 16″ and the other heating element 15 lies in a planar manner against the second heat transfer body 16″. The heating elements 15 lying against the first heat transfer body 16′ are also designated below as first heating elements 15′. The heating elements 15 lying against the second heat transfer body 16″ are also designated below as second heating elements 15″. The heating module has here four electrical connections 26. A first electrical connection 26′ and a second electrical connection 26″ are mounted on the first heat transfer body 16′, wherein the first electrical connection 26′ serves for the electrical supply of the cold conductor elements 2 and the heating elements 15 lying against the first heat transfer body 16′, for example a connection of the cold conductor elements 2 and the said heating elements 15 at a first pole, in particular a minus pole, of a voltage source. The second electrical connection 26″ serves for the electrical supply of the first heating elements 15′ with a second other pole, for example the plus pole, of the voltage source. For this purpose, the first electrical connection 26′ is electrically connected via electrical lines 29 both with the cold conductor elements 2 and also with the first heating elements 15′. By comparison, the second electrical connection 26″ is connected via electrical lines 29 exclusively with the first heating elements 15′. A third electrical connection 26′″ and a fourth electrical connection 26″″ are mounted on the second heat transfer body 16″. The third electrical connection 26′″ serves for the electrical supply of the cold conductor elements 2 and second heating elements 15″ with the second pole of the voltage source, therefore for example the plus pole. Accordingly, the third electrical connection 26′″ is connected via electrical lines 29 with the cold conductor elements 2 and the second heating elements 15″. The fourth electrical connection 26″″ serves for the electrical supply of the second heating elements 15″ with the first pole of the voltage source, therefore for example the minus pole. Accordingly, the fourth electrical connection 26″″ is electrically connected via electrical lines 29 exclusively with the second heating elements 15″. Therefore, the heating module 14 shown in FIGS. 6 to 8 can be operated and electrically supplied more variably. In particular, the first heating elements 15′ and the second heating elements 15″ can be electrically supplied separately and individually. In addition, therefore, the first heating elements 15′ are connected in series and connected in parallel to the cold conductor elements 2. Furthermore, the second heating elements 15″ are connected in series and connected in parallel to the cold conductor elements 2. Furthermore, in this way, the cold conductor elements 2 are connected in series.
[0080] FIGS. 9 to 11 show another example embodiment of the heating module 14. Here, FIG. 9 shows a section through the heating module 14 along the longitudinal direction 25. FIGS. 10 and 11 show sections through the heating module 14 along the plane illustrated in dashed lines in FIG. 9, wherein FIG. 10 shows the section in the direction of a first of the heat transfer bodies 16, also designated below as first heat transfer body 16′, and FIG. 11 shows the section in the direction of the other heat transfer body 16, also designated below as second heat transfer body 16″. In this example embodiment, the neighbour direction 20 runs parallel to the transverse direction 24, corresponds in particular to the transverse direction 24. The heating module 14 shown in FIGS. 9 to 11 is accordingly also formed as a heating rod 30 and has a total of six cold conductor elements 2, which are formed as cold conductor blocks 21 and are arranged in longitudinal direction 25 adjacent to one another and in transverse direction 24 centrally to the heat transfer bodies 16. The heating module 14 shown in FIGS. 9 to 11 has, in addition, two heating elements 15 which are respectively spaced apart with respect to the cold conductor elements 2. The heating elements 15 are arranged lying opposite in transverse direction 24, in such a way that the cold conductor elements 2 are arranged in transverse direction 24 between the heating elements 15. The respective heating element 15 can be a web-shaped resistance heater 23 or a web-shaped thick film heater 22. The heating module 14 has, in addition, two electrical connections 26, which are only shown in FIGS. 10 and 11. The heating elements 15 are connected with one another via an electrical line 29. In addition, one of the heating elements 15 is connected with a first of the electrical connections 26′, and the other heating element 15 is connected with the second electrical connection 26″ via electrical lines 29, so that the heating elements 15 are connected in series. The cold conductor elements 2 are connected with one another via electrical lines 29. In addition, one of the cold conductor elements 2 is connected via electrical lines 29 with the first electrical connection 26′ and with the second electrical connection 26″, so that the cold conductor elements 2 are connected in series and so that the cold conductor elements 2 and the heating elements 15 are connected in parallel.
[0081] FIG. 13 shows a section through the heating device 31 in another example embodiment. This example embodiment differs from the example embodiment shown in FIG. 12 in particular in that the heating device 31 has six heating modules 14. Here, between the adjacent heating modules 14 which are arranged spaced apart from one another, structures 33, in particular a rib structure 34 or respectively a grid 38, are arranged. As can be seen from FIG. 13, the heating modules 14 are respectively formed identically, wherein the heating modules 14 in FIG. 13 correspond purely by way of example respectively to the heating module 14 of FIGS. 9 to 11. In this example embodiment, the flow path 32 runs along the longitudinal direction 25 between the heating modules 14.
[0082] A further example embodiment of the heating device 31 is shown in FIG. 14. This example embodiment differs from the example embodiment shown in FIG. 13 in that different heating modules 14 are provided. The heating modules 14 shown in FIG. 14 differ from the heating modules 14 shown in FIG. 13 in that the respective heating module 14 has only one heating element 15, which in particular can be web-shaped, which is spaced apart with respect to the cold conductor elements 2 in transverse direction 24.
[0083] The cold conductor elements 2 of the respective heating module 14 provide, in operation, a heating output which is also designated below as cold conductor heating output. The heating output, provided in operation, of the at least one heating element 15 is also designated below as heating element heating output, and the total heating output of the heating module 14 is also designated below as total heating output.
[0084] The heating modules 14 are preferably configured in such a way that a maximally available cold conductor heating output of the cold conductor elements 2 corresponds to between 80% and 95% of the maximum total heating output of the heating module 14. In addition, a maximum heating output of the at least one heating element 15 is at least as great as the difference between the maximum total heating output and the maximum cold conductor heating output.
[0085] The respective heating device 31 can be operated as follows with the aid of the control device 43, the determining device 42 and the switching device 39.
[0086] When the temperature at least of one of the at least one cold conductor elements 2 of one of the heating modules 14 lies below the starting temperature 5 of the cold conductor element 2, then the heating device 31 is operated in a starting operation. The taking into consideration of the temperature of the cold conductor element 2 takes place here with the aid of the determining device 42. In the starting operation, an electrical supply of the at least one cold conductor element 2 of the heating module 14 is interrupted, so that the cold conductor element 2 is not flowed through by an electrical current. By comparison, the at least one heating element 15 of the heating module 14 is supplied electrically. The electrical supply or respectively the interruption of the electrical supply of the respective element 2, 15 takes place here by the switching device 39. Therefore, in the starting operation, firstly exclusively heat is generated with the at least one heating element 15. Through the heat-transferring connection of the at least one heating element 15 with the at least one cold conductor element 2, therefore the temperature of the cold conductor element 2 also rises. When the temperature of the at least one cold conductor element 2 exceeds the starting temperature 5 of the cold conductor element 2, the cold conductor element 2 is also supplied electrically. Therefore, the NTC range 7 of the cold conductor element 2 and the transition between the NTC range 7 and the PTC range 12, in which electrical current peaks and voltage peaks can occur, is jumped over. When the at least one cold conductor element 2 is electrically supplied, then the cold conductor element 2 also generates heat and therefore contributes at least to the total heating output of the heating module 14. With the electrical supply of the at least one cold conductor element 2 on reaching or respectively exceeding the starting temperature 5 of the cold conductor element 2, the operation of the heating module 14 passes into a regular operation.
[0087] Within a possible regular operation, also designated below as first regular operation, the electrical output which is fed to the at least one heating element 15 can be reduced here and therefore also can be interrupted, when a maximum operating temperature of the heating module 14 is reached. The maximum operating temperature of the heating module 14 is predetermined here. The maximum operating temperature can correspond here in particular to the end temperature 10 of the at least one cold conductor element 2.
[0088] Alternatively it is possible, in the starting operation with the electrical supplying of the at least one cold conductor element 2, to interrupt the electrical supplying of the at least one heating element 15. This means that in the subsequent regular operation, the total heating output of the heating module 14 is provided exclusively through the at least one cold conductor element 2. This takes place within an alternative regular operation, also designated below as second regular operation. In the second regular operation, the required total heating output to the heating module 14 is provided exclusively with the at least one cold conductor element 2, i.e. in particular without the at least one heating element 15. This takes place until the required total heating output exceeds the maximum heating output of the at least one cold conductor element 2 and therefore the maximum cold conductor heating output. In this case, also at least one of the at least one heating elements 15 is supplied electrically, in order to provide the difference between the maximum cold conductor heating output and the required total heating output.
[0089] Of course, the heating device 31 can be operated in the starting operation, when the temperature at least of one of the at least one cold conductor elements 2 of the heating module 14 falls below the starting temperature 5 of the cold conductor element 2.
[0090] In the respective heating device 31, the respective heating module 14 can be operated individually in the manner described above. It is also conceivable to operate at least two of the heating modules 14 of the heating device 31 through a corresponding interconnection jointly in the manner described above.
