PTC HEATING MODULE FOR HEATING A FLUID

Abstract

A PTC heating module for heating a fluid may include at least one first electrically conductive contact electrode and at least one second electrically conductive contact electrode arranged spaced apart from each other, at least one insulator layer attached to the at least one first contact electrode and the at least one second contact electrode, and at least one PTC thermistor element having a thickness. The at least one PTC thermistor element may have a first main surface and a second main surface disposed opposite each other relative to the thickness. The at least one first contact electrode may be in contact with a contact area of the first main surface and the at least one second contact electrode may be in contact with a contact area of the second main surface. At least one of a clearance distance and a creepage distance may be greater than the thickness.

Claims

1. A PTC heating module for heating a fluid comprising: at least one first electrically conductive contact electrode and at least one second electrically conductive contact electrode arranged spaced apart from each other; at least one insulator layer coupled to the at least one first contact electrode and the at least one second contact electrodes; at least one PTC thermistor element having a thickness; the at least one PTC thermistor element having a first main surface and a second main surface disposed opposite each other at a distance from the thickness of the at least one PTC thermistor element; at least the first main surface divided into a contact area and a rest area, the contact area including an electrically conductive coating; the second main surface having a contact area including an electrically conductive coating; the at least one first contact electrode in contact with the contact area of the first main surface and the at least one second contact electrode in contact with the contact area of the second main surface; and wherein at least one of a clearance distance and a creepage distance between the at least one first contact electrode and the at least one second contact electrode is greater than the thickness of the at least one PTC thermistor element.

2. The PTC heating module according to claim 1, wherein the second main surface is divided into the contact area and a rest area.

3. The PTC heating module according to claim 1, wherein the at least one of the clearance distance and and the creepage distance is at least 1.5 times the thickness of the at least one PTC thermistor element.

4. The PTC heating module according to claim 1, wherein: the at least one PTC thermistor element includes at least two PTC thermistor elements arranged at a distance from each other; and the at least one first contact electrode connects respective contact areas of respective first main surfaces of the at least two PTC thermistor elements in an electrically conductive manner, and the at least one second contact electrode connects respective contact areas of respective second main surfaces of the at least two PTC thermistor elements in an electrically conductive manner.

5. The PTC heating module according to claim 2, wherein at least one of the contact area of the first main surface and the contact area of the second main surface has a rectangular shape and a corresponding one of the rest area of the first main surface and the rest area of the second main surface is U-shaped.

6. The PTC heating module according to claim 2, wherein at least one of the contact area of the first main surface and the contact area of the second main surface has a T-shape and a corresponding one of the rest area of the first main surface and the rest area of the second main surface is U-shaped.

7. The PTC heating module according to claim 2, wherein at least one of the contact area of the first main surface and the contact area of the second main surface has a rectangular shape and a corresponding one of the rest area of the first main surface and the rest area of the second main surface is L-shaped.

8. The PTC heating module according to claim 2, wherein at least one of the contact area of the first main surface and the contact area of the second main surface has a rectangular shape and a corresponding one of the rest area of the first main surface and the rest area of the second main surface is rectangular shaped.

9. The PTC heating module according to claim 2, wherein at least one of the contact area of the first main surface and the contact area of the second main surface has a rectangular shape and a corresponding one of the rest area of the first main surface and the rest area of the second main surface includes two rectangular shaped subareas separated from each other by a corresponding one of the contact area of the first main surface and the contact area of the second main surface.

10. The PTC heating module according to claim 1 wherein the at least one first contact electrodes contacts an entire surface of the contact area of the first main surface, and wherein the at least one second contact electrode contacts an entire surface of the contact area of the second main surface.

11. The PTC heating module according to claim 1, wherein a part of one of the at least one first contact electrode and the at least one second contact electrode that is not in contact with the contact area of a corresponding main surface is disposed at a distance from the corresponding main surface.

12. A heating device for heating a fluid comprising a plurality of PTC heating modules arranged spaced apart from each other, each of the plurality of PTC heating modules including: at least one first electrically conductive contact electrode and at least one second electrically conductive contact electrode arranged spaced apart from each other; at least one insulator layer coupled to the at least one first contact electrode and the at least one second contact electrode; at least one PTC thermistor element having a thickness; the at least one PTC thermistor element having a first main surface and a second main surface disposed opposite each other at a distance from the thickness of the at least one PTC thermistor element at least the first main surface divided into a contact area and a rest area, the contact area including an electrically conductive coating; the second main surface having a contact area including an electrically conductive coating; the at least one first contact electrode in contact with the contact area of the first main surface and the at least one second contact electrode in contact with the contact area of the second main surface; and wherein at least one of a clearance distance and a creepage distance between the at least one first contact electrode and the at least one second contact electrode is greater than the thickness of the at least one PTC thermistor element.

13. The heating device according to claim 12, wherein at least one of the plurality of PTC heating modules is arranged such that the first main surface and the second main surfaces of the at least one PTC thermistor element extend substantially parallel to a flow direction of the fluid.

14. The heating device according to claim 12, wherein the heating device is connectable to a voltage source such that one of the at least one first contact electrode and the at least one second contact electrode of one of the plurality of PTC heating modules is supplyable with an operating voltage.

15. The heating device according to claim 12, wherein the heating device is integrateable in a vehicle as at least one of an air-side auxiliary heater and a coolant-side auxiliary heater.

16. The heating device according to claim 12, wherein the second main surface is divided into the contact area and a rest area.

17. The heating device according to claim 12, wherein the at least one of the clearance distance and the creepage distance is at least 1.5 times the thickness of the at least one PTC thermistor element.

18. The heating device according to claim 12, wherein: the at least one PTC thermistor element includes at least two PTC thermistor elements arranged at a distance from each other; the at least one first contact electrode connects respective contact areas of respective first main surfaces of the at least two PTC thermistor elements in an electrically conductive manner; and the at least one second contact electrode connects respective contact areas of respective second main surfaces of the at least two PTC thermistor elements in an electrically conductive manner.

19. The heating device according to claim 12, wherein a part of one of the at least one first contact electrode and the at least one second contact electrode that is not in contact with the contact area of a corresponding main surface is disposed at a distance from the corresponding main surface.

20. A PTC heating module for heating a fluid comprising: at least one first electrically conductive contact electrode and at least one second electrically conductive contact electrode arranged spaced apart from each other; at least one insulator layer coupled to the at least one first contact electrode and the at least one second contact electrode; at least one PTC thermistor element having a thickness, a first main surface, and a second main surface, the first main surface and the second main surface disposed opposite one other relative to the thickness of the at least one PTC thermistor element; the first main surface divided into a first contact area and a first rest area, the first contact area including an electrically conductive coating; the second main surface divided into a second contact area and a second rest area, the second contact area including an electrically conductive coating; the at least one first contact electrode in contact with an entire surface of the first contact area and the at least one second contact electrode in contact with an entire surface of the second contact area; and wherein at least one of a clearance distance and a creepage distance between the at least one first contact electrode and the at least one second contact electrode is greater than the thickness of the at least one PTC thermistor element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In the drawings, in each case schematically,

[0038] FIG. 1 shows a cross-section of a PTC heating module according to the invention,

[0039] FIG. 2 shows a perspective view of the components arranged within the PTC heating module of FIG. 1,

[0040] FIG. 3 shows a perspective view of a PTC thermistor element with T-shaped contact areas,

[0041] FIG. 4 shows a perspective view of a PTC thermistor element with L-shaped rest areas,

[0042] FIG. 5 shows a perspective view of a PTC thermistor element with differently divided main surfaces,

[0043] FIG. 6 shows a perspective view of a further PTC thermistor element.

DETAILED DESCRIPTION

[0044] According to FIG. 1, a PTC heating module 1 according to the invention has a housing 2 with a rectangular cross-section. A first electrically conductive contact electrode 3 and a second electrically conductive contact electrode 4 are arranged spaced apart from each other in the housing 2. If the housing 2 consists of an electrically conductive material, an insulator layer 5 is provided between the respective contact electrode 3,4 and housing 2. The insulator layer 5 prevents an electrically conductive connection between the contact electrodes 3,4 and housing 2. The insulator layer 5 may be provided as in FIG. 1 within the housing 2 on partial surfaces. It is also conceivable that the inner surface of the housing 2 is completely provided with the insulator layer 5.

[0045] A cuboidal PTC thermistor element 6 is arranged between the first contact electrode 3 and the second contact electrode 4 and has a rectangular cross-section as shown in FIG. 1. The PTC thermistor element 6 has a surface with a first main surface 8 and a second main surface 9 which are spaced opposite each other at a distance from the thickness 7 of the PTC thermistor element 6. The first main surface 8 is aligned substantially parallel to the second main surface 9. The two main surfaces 8,9 together comprise the largest part of the surface of the PTC thermistor element 6.

[0046] The first main surface 8 is divided into a contact area 10 with an electrically conductive coating 12 and a rest area 11. The first contact electrode 3 is in contact with the contact area 10 of the first main surface 8 and is electrically connected to it. The second main surface 9 is divided into a contact area 10a with an electrically conductive coating 12a and a rest area 11a. The second contact electrode 4 is in contact with the contact area 10a of the second main surface 9 and is electrically connected to it. Areas of the surface without an electrically conductive coating as well as rest areas 11 and 11a are electrically insulating.

[0047] If the contact electrodes 3 and 4 are supplied with an operating voltage, a current flow through the PTC thermistor element 6 occurs along a current flow direction of 19. The contact areas 10 and 10a and the respective contact electrodes 3 and 4 are arranged in such a way that that the shortest path of the current flow inside the PTC thermistor element 6 substantially corresponds to the thickness 7 of the PTC thermistor element 6.

[0048] The free area inside the housing 2 is filled with air which has a certain dielectric strength. Given a predetermined operating voltage between the first contact electrode 3 and the second contact electrode 4, a sufficient clearance and/or creepage 13 is required in order to avoid short-circuits between the contact electrodes 3 and 4. The clearance and/or creepage 13 comprises the thickness 7 of the PTC thermistor element 6 and additionally the shortest path along the respective rest area 11 and/or 11a. Thus, the clearance and/or creepage 13 is larger than the thickness 7 of the PTC thermistor element 6. Using a thinner PTC thermistor element 6 reduces an unwanted overheating due to the low thermal conductivity of the material of the PTC thermistor element 6 and increases the achievable heating performance that can be dissipated via the surface to heat the fluid.

[0049] A non-pictured electrical heater has at least one PTC heater module 1 which is oriented such that the current flow direction 19 is substantially transverse to the fluid flow direction 14. As a result, the first main area 8 and the second main area 9 are aligned substantially parallel to the fluid flow direction 14. Such an alignment of the PTC heating module 1 has the advantage that the maximum possible heat transfer to the fluid is achieved since the contact time between the fluid and the housing 2 is maximized.

[0050] FIG. 2 shows a perspective representation of two PTC thermistor elements 6 spaced apart from each other. The first main surfaces 8 are in a common plane and the second main surfaces 9 are in another common plane. The dashed lines in this representation and the following representations symbolize hidden edges.

[0051] The PTC thermistor elements 6 are cuboid-shaped and have front faces 15 and side faces 16 while the front faces 15 of two adjacent PTC thermistor elements 6 face each other. The contact electrodes 3 and 4 each have a longitudinal bar 17 and several transverse bars 18, the longitudinal bars 17 are arranged on the sides of the side faces 16. The contact areas of the first main surfaces 8 are not visible in FIG. 2. The transverse bars 18 of the first contact electrode 3 contact these contact areas over their entire surface and connect them electrically conductive. The transverse bars 18 of the second contact electrode 4 contact the not shown contact areas of the second main surfaces 9 over their entire surface and connect them electrically conductive. This results in a parallel connection of the PTC thermistor elements 6.

[0052] FIG. 3 shows a PTC thermistor element 6 with a first surface 8 that has a T-shaped contact area 10 and a U-shaped rest area 11. The second surface 9 has a T-shaped contact area 10a and a U-shaped rest area 11a. The arrangement of the contact area and rest area of the opposing main surfaces 8,9 is mirrored.

[0053] FIG. 4 shows a PTC thermistor element 6 with a first surface 8 that has a rectangular shaped contact area 10 and a L-shaped rest area 11. The second surface 9 has a rectangular shaped contact area 10a and a L-shaped rest area 11a. The arrangement of the contact area and rest area of the opposing main surfaces 8,9 is mirrored.

[0054] FIG. 5 shows a PTC thermistor element 6 with a first surface 8 that has a rectangular shaped contact area 10 and a U-shaped rest area 11. The second surface 9 has a rectangular shaped contact area 10a and a rectangular shaped rest area 11a. The arrangement of the contact area and rest area of the opposing main surfaces 8,9 is mirrored. The longitudinal extension directions of the contact area 10 and contact area 10a are substantially perpendicular to each other.

[0055] FIG. 6 shows a PTC thermistor element 6 with a first surface 8 that has a rectangular shaped contact area 10 and a rest area 11 with two rectangular shaped subareas which are separated by the contact area 10. The second surface 9 has a rectangular shaped contact area 10a and a rest area 11a with two rectangular shaped subareas which are separated by the contact area 10a. The longitudinal extension directions of the contact area 10 and contact area 10a are substantially perpendicular to each other.