Electric heating device for heating fluids

Abstract

An electric heating device for heating fluids, comprising a housing, inlet and outlet connection pieces arranged at inlet and outlet openings of the housing, respectively, a flow path in the housing through which the fluid to be heated flows leading from the inlet connection piece to the outlet connection piece, and an electric heating unit attached to the housing. The flow path comprises inlet and outlet chambers and at least two flow channels running side by side from the inlet to the outlet chambers. A separating wall separates two flow channels from one another. Each flow channel has an inlet section connected to the inlet chamber and defining an inlet flow direction and an outlet section connected to the outlet chamber and defining an outlet flow direction. The inlet connection piece is oriented in the inlet flow direction and/or the outlet connection piece is oriented in the outlet flow direction.

Claims

1. An electric heating device for heating fluids, comprising: a housing having an upper housing part, a lower housing part and housing walls arranged on the upper and lower housing parts, the housing walls including two base walls wherein the upper housing part and the lower housing part each define one of the base walls; an inlet connection piece arranged at an inlet opening of the housing and an outlet connection piece arranged at an outlet opening of the housing; a flow path through which the fluid to be heated can flow and which is disposed inside the housing and leads from the inlet connection piece to the outlet connection piece; an electric heating unit attached to at least one of the housing walls outside of the flow path; wherein the flow path comprises an inlet chamber, an outlet chamber and at least two flow channels running side by side from the inlet chamber to the outlet chamber; wherein each of the at least two flow channels starts at the inlet chamber and ends at the outlet chamber; wherein at least one of the housing walls is a separating wall that separates two side-by-side channels of the at least two flow channels from one another wherein opposite sides of the separating wall defines a portion of each of the two side-by-side channels; wherein each of the at least two flow channels has an inlet section connected to the inlet chamber and defining an inlet flow direction and each of the at least two flow channels has an outlet section connected to the outlet chamber and defining an outlet flow direction and wherein each of the at least two flow channels are disposed between and partially defined by the base walls on the upper and lower housing parts; wherein the inlet connection piece is oriented in the inlet flow direction and/or the outlet connection piece is oriented in the outlet and wherein the housing walls arranged on the upper and lower housing parts define at least one gap between the housing walls permitting fluid leakage from one of the side-by-side fluid channels to the other side-by-side fluid channel.

2. The heating device according to claim 1, wherein the base walls extend transversely to the separating wall.

3. The heating device according to claim 2, wherein the base walls are planar and the at least two flow channels run parallel thereto.

4. The heating device according to claim 3, wherein the inlet connection piece and the at least two flow channels are arranged on opposite sides of a plane defined by one of the base walls.

5. The heating device according to claim 3, wherein the outlet connection piece and the at least two flow channels are arranged on opposite sides of a plane defined by one of the base walls.

6. The heating device according to claim 2, wherein, when viewed transversely to the base walls, the inlet connection piece is centered with the inlet sections of the at least two flow channels.

7. The heating device according to claim 2, wherein the separating wall projects from one of the base walls toward the other base wall and the at least one gap permitting fluid leakage from one of the side-by-side fluid channels to the other side-by-side fluid channel is disposed between the separating wall and the other base wall.

8. The heating device according to claim 1, wherein, when viewed transversely to one of the base walls, the outlet connection piece is oriented to the outlet section of an outer one of the at least two flow channels, which is adjacent to an outer side wall, which connects the base wall of the lower housing part and the base wall of the upper housing part.

9. The heating device according to claim 2, wherein a section of the inlet chamber adjacent to the at least two flow channels is limited by a section of each of the base walls.

10. The heating device according to claim 1, wherein the inlet chamber and/or the outlet chamber comprises a tapering section.

11. The heating device according to claim 1, wherein the open cross section of the inlet chamber decreases continuously towards the inlet connection piece.

12. The heating device according to claim 11, wherein, when viewed transversely to the base walls, the inlet chamber has a width that decreases towards the inlet connection piece.

13. The heating device according to claim 11, wherein, when viewed transversely to the flow direction and along the base walls, the inlet chamber has a height that increases towards the inlet connection piece.

14. The heating device according to claim 1, wherein the open cross section of the outlet chamber decreases continuously towards the outlet connection piece.

15. The heating device according to claim 14, wherein, when viewed transversely to the base walls, the outlet chamber has a width that decreases towards the outlet connection piece.

16. The heating device according to claim 14, wherein, when viewed transversely to the flow direction and along the base walls, the outlet chamber has a height that increases towards the outlet connection piece.

17. The heating device according to according to claim 2, wherein the separating wall projects from a first one of the base walls and has a width which decreases with increasing distance from the first base wall and wherein the electric heating unit is attached to the first base wall.

18. The heating device according to claim 1, wherein the separating wall starts at the inlet chamber and ends at the outlet chamber.

19. An electric heating device for heating fluids, comprising: a housing having an upper housing part, a lower housing part and housing walls arranged on the upper and lower housing parts, the housing walls including two base walls wherein the upper housing part and the lower housing part each define one of the base walls; an inlet connection piece arranged at an inlet opening of the housing and an outlet connection piece arranged at an outlet opening of the housing; a flow path through which the fluid to be heated can flow and which is defined inside the housing and leads from the inlet connection piece to the outlet connection piece; an electric heating unit attached to at least one of the housing walls outside of the flow path; wherein the flow path comprises an inlet chamber, an outlet chamber and at least two flow channels running side by side from the inlet chamber to the outlet chamber; wherein the base walls define opposing surfaces of each of the at least two flow channels; wherein at least one of the housing walls is a separating wall that extends transversely to the base wall and separates two adjacent flow channels of the at least two flow channels from one another with opposite sides of the separating wall defining a portion of each of the two adjacent flow channels; wherein each of the at least two flow channels has an inlet section connected to the inlet chamber and defining an inlet flow direction and each of the at least two flow channels has an outlet section connected to the outlet chamber and defining an outlet flow direction; wherein each of the two adjacent flow channels define a curved path and the two adjacent flow channels define different lengths from the inlet chamber to the outlet chamber and a shorter length channel of the two adjacent flow channels has a larger open cross sectional area than a longer length channel of the two adjacent flow channels; and wherein the inlet connection piece is oriented in the inlet flow direction and/or the outlet connection piece is oriented in the outlet flow direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above-mentioned aspects of exemplary embodiments will become more apparent and will be better understood by reference to the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

(2) FIG. 1 shows a perspective view of a lower housing part of an electric heating device according to this disclosure;

(3) FIG. 2 shows a perspective view of an inlet area of another embodiment of a lower housing part;

(4) FIG. 3 shows a top view of an outlet area of the lower housing part of FIG. 2; and

(5) FIG. 4 shows a perspective view of FIG. 3.

DESCRIPTION

(6) The embodiments described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of this disclosure.

(7) The heating device partly illustrated in FIGS. 1 to 4 is used to heat aqueous fluids in vehicles, in particular mixtures made of water and antifreeze agent, such as glycol. The electric heating device has a housing, which comprises a lower housing part 1 and an upper housing part (not shown). An inlet connection piece 2 is arranged at an inlet opening of the lower housing part 1. An outlet connection piece 3 is arranged at an outlet opening of the lower housing part 1. A flow path is defined inside the housing and leads from the inlet connection piece 2 to the outlet connection piece 3. The fluid to be heated can flow through the flow path. The flow path comprises an inlet chamber 4, an outlet chamber 5 and four flow channels 8 running side by side and parallel to each other from the inlet chamber 4 to the outlet chamber 5. Each flow channel 8 has an inlet section 6 being connected to the inlet chamber 4. Each flow channel 8 has an outlet section 7, which is connected to the outlet chamber 5. The lower housing part 1 has three ribs or separating walls 9, each of which separates two flow channels 8 from one another. In FIG. 1, the flow channels 8 are U-shaped and have a straight inlet section 6 and a straight outlet section 7 connected by a curved section. The lengths of the four flow channels 8 in FIG. 1 are therefore different.

(8) The inlet sections 6 define an inlet flow direction which extends along the straight inlet section 6 of the flow channel 8. The inlet connection piece 2 is oriented in the inlet flow direction, so that the flow direction in the inlet connection piece 2 is parallel to the flow direction in the inlet sections 6. The outlet sections 7 define an outlet flow direction, which is parallel to the inlet flow direction. The outlet connection piece 3 is oriented in the outlet flow direction, so that the flow in the outlet connection piece 3 flows parallel to the flow in the outlet sections 7.

(9) The lower housing part 1 comprises a base wall 10, which limits the flow channels 8 and extends perpendicular to the separating walls 9. The base wall 10 is planar and the flow channels 8 run parallel thereto. The electric heating device comprises an electric heating unit (not shown), which is attached to the back side of the base wall 10 and which can heat the base wall 10 from the underside. The heat from the heating unit is conducted through the base wall 10 and conducted by the separating walls 9 to the flow channels 8, in which the fluid to be heated can flow. The separating walls 9 have a width, which decreases with increasing distance from the base wall 10. The heating unit does not come into contact with the aqueous fluid to be heated, because it is arranged outside the flow path. In FIG. 1 is shown that the inlet connection piece 2 is arranged on the opposite side of a plane defined by the base wall 10 with respect to the flow channels 8. The outlet connection piece 3 and the flow channels 8 are arranged on opposite sides of a plane defined by the base wall 10.

(10) To form a closed flow path in the sections of the inlet chamber 4, the flow channels 8 and the outlet chamber 5, an upper housing part (not shown) is provided onto the lower housing part 1. The upper housing part also has a base wall, whichafter assemblycovers the lower housing part 1 and extends parallel to the base wall 10 of the lower housing part 1. The housing further has an outer side wall 11, which connects the base wall 10 of the lower housing part 1 and the base wall of the upper housing part (not shown). A seal can be arranged on the outer side wall 11 between the upper and lower housing part. The base wall of the upper housing part can contact the separating walls 9 of the lower housing part 1. In an alternative, the upper housing part can also comprise separating walls which are designed mirror-symmetrically to the separating walls 9 of the lower housing part 1, so that the chamber 4, 5 and the flow channels 8 are partly arranged in the upper and lower housing parts.

(11) In FIGS. 2, 3 and 4, a further embodiment of an electric heating device is shown, which differs from the embodiment shown in FIG. 1 in that four flow channels 8 run straight and parallel along their entire lengths. Identical and corresponding parts are denoted with agreeing reference numerals, so that a repeated description can be omitted.

(12) The inlet connection piece 2 is centered to the inlet sections 6 of the flow channels 8 when the lower housing part 1 is viewed perpendicular to the base wall 10, see in particular FIG. 2. The outlet connection piece 3 is oriented to the outlet section 7 of an outer flow channel 8, which is adjacent to the outer side wall 11, when the lower housing part 1 is viewed perpendicular to the base wall 10, see in particular FIGS. 3 and 4.

(13) The inlet chamber 4 and the outlet chamber 5 both have tapering sections, each of which is formed by a surface, which is inclined to the flow direction. The length of the tapering section of the inlet chamber 4 corresponds approximately to the length of the tapering section of the outlet chamber 5. The open cross section of the inlet chamber 4 decreases continuously towards the inlet connection piece 2. A section of the inlet chamber 4 adjacent to the inlet sections 6 of the flow channels 8 is limited by a section of the planar base wall 10. In FIGS. 1 and 2, the reference line leading to reference numeral 4 begins in the first section of the inlet chamber having the changing open cross section, and the reference line leading to reference numeral 10 begins in the second section of the inlet chamber being limited by a section of the base wall 10 and having a constant open cross section. In other words, the open cross section of the flow path is constant in the inlet connection piece 2, then increases in the first section of the inlet chamber 4 and then remains constant again in the second section of the inlet chamber 4 which is limited by the base wall 10. The open cross section of the following flow path is constant throughout the flow channels 8. Thereafter, the open cross section of the outlet chamber 5 decreases continuously towards the outlet connection piece 3. When viewed perpendicular to the base wall 10, the inlet chamber 4 decreases its width towards the inlet connection piece 2 and the outlet chamber 5 decreases its width towards the outlet connection piece 3. When viewed parallel to the base wall 10 and transversely to the flow direction, the inlet chamber 4 increases its height towards the inlet connection piece 2 and the outlet chamber 5 increases its height towards the outlet connection piece 3.

(14) While exemplary embodiments have been disclosed hereinabove, the present invention is not limited to the disclosed embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of this disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

LIST OF REFERENCE SIGNS

(15) 1 Lower housing part 2 Inlet connection piece 3 Outlet connection piece 4 Inlet chamber 5 Outlet chamber 6 Inlet sections of flow channels 7 Outlet sections of flow channels 8 Flow channels 9 Separating walls 10 Base wall 11 Outer side wall