US20060237180A1

US20060237180A1 - Air heat exchanger

Info

Publication number: US20060237180A1
Application number: US11/406,817
Authority: US
Inventors: Norman Anke; Franz Feuerstein
Original assignee: Liebherr Aerospace Lindenberg GmbH
Current assignee: Liebherr Aerospace Lindenberg GmbH
Priority date: 2005-04-19
Filing date: 2006-04-18
Publication date: 2006-10-26
Also published as: DE102005018050A1; EP1715272A1; CA2543382A1

Abstract

The present disclosure relates to an air heat exchanger in air diffuser systems with flexible planar heat exchanger elements, in particular for use in aircraft. In accordance with the present disclosure, the individual planar heat exchanger elements are connected with each other by means of webs. The present disclosure furthermore relates to a method for manufacturing air heat exchangers as well as to a use thereof.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to German Patent Application Serial No. 10 2005 018 050.7 filed Apr. 19, 2005, which is hereby incorporated by reference in its entirety for all purposes.

FIELD

The present disclosure relates to an air heat exchanger in air diffuser systems with flexible planar heat exchanger elements, in particular for use in aircraft.

BACKGROUND AND SUMMARY

For heating the air, heaters are incorporated in air diffuser systems. For safety reasons, heating elements with high surface temperatures are undesirable in the aircraft industry. Therefore, so-called panel heating elements are being used. Due to their large surface area, the same are capable of transferring a high thermal power despite low temperatures. The objective is to install a rather large surface area on a small space, in order to be able to transfer as much heat as possible. Output of the thermal power should be effected in a controlled way, and inadmissible excess temperatures should be avoided. This is ensured by the use of sensors and fuses. Therefore, the elements should be producible at low cost and should achieve a rather high performance with a low weight and a small size.
Air heaters with a structure as shown in the attached FIG. 1 are known already. In an air-conducting tube 12 to be heated, flexible panel heating elements 10 are inserted, which in the illustrated embodiment are arranged parallel to each other. In this case, the panel heating elements constitute free-standing plates. As an alternative to the illustrated embodiment, the panel heating elements can also consist of coaxially arranged tubes. There can also be provided heat-dissipating cooling bodies, for instance in the form of heat exchanger lamellae.
These prior art systems involve a very high contacting effort, as the individual panel heating elements must be connected with each other via soldering points, plug-in connections and the like. As a result, the risk of defects is substantially increased during the manufacture of such elements. In particular the manufacture of coaxial panel heating elements involves a substantially higher mounting effort as compared to plate-shaped elements.
It is the object of the present disclosure to create an air heat exchanger which is comparatively easier to manufacture and to install.
In accordance with the present disclosure, this object is solved by an air heat exchanger in an air diffuser system comprising flexible planar heat exchanger elements, in particular for use in aircraft, wherein the individual planar heat exchanger elements are connected with each other by means of webs.
In one example, these webs themselves are unheated. Inside these webs, conductors are disposed, which connect the individual heat exchanger conductors in the individual surfaces with each other. The webs only serve the mechanical connection of the planar heat exchanger elements. The corresponding conductors usually, but not necessarily, are electric conductors.
Accordingly, the planar heat exchanger elements can have a variable design in terms of shape, size and heat exchanger performance. Thus, they can result in a much better utilization of the flow cross-section of the air-conducting conduit. In certain portions of round tubes, for instance, flow can be greater, so that they can provide a greater heat exchanger performance.
To effect a uniform surface temperature of the flexible heat exchanger elements in the direction of the traversed length, the same can also be equipped with a variable power density along their length. With a specified maximum temperature, which should not be exceeded, a uniform temperature can thus be adjusted along the length of the tube.
Particularly advantageously, additional heat exchanging bodies are provided, for instance plates and/or ribs. The additional heat exchanging bodies can be used both as supports and as spacers for the planar heat exchanger elements.
The above-mentioned object of the present disclosure is solved in particular by a method wherein, the planar heat exchanger elements are manufactured together with the webs connecting the same as an integral element.
Accordingly, the sensors or other fuses for monitoring the temperature as well as connecting lines leading to the same can be integrated right during the manufacturing process of the planar heat exchanger elements and the webs connecting the same.
Upon manufacture of the planar heat exchanger elements and the webs of each element, the same is bent into its final shape. As far as the heat exchanger element is incorporated in a pipe conduit, the same will afterwards be inserted into the pipe conduit. In accordance with the herein disclosed aspect of the air heat exchanger, it is no longer necessary to connect each individual planar heat exchanger element separately. Rather, it is sufficient to connect the entire planar heat exchanger element to the heat exchanger fluid conduit.
Particularly advantageously, the aforementioned air heat exchanger is used as an air heater, preferably for use in aircraft.
Further details, features and advantages of the present disclosure will be illustrated with reference to an embodiment shown in the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a partly sectioned air heat exchanger in accordance with the prior art; and
FIG. 2 shows several views of a part of an air heat exchanger in various structural conditions in accordance with the present invention.

DETAILED DESCRIPTION

In FIGS. 2 a to 2 c, the various manufacturing steps of an air heat exchanger 20 are shown. The same first of all consists of a number of planar heat exchanger elements 10, which are each connected with each other by means of webs 14. The webs 14 substantially have the same structure as the heat exchanger elements 10, which in the present embodiment constitute panel heating elements. Instead of corresponding panel heating elements, the same can of course also constitute panel cooling elements when used in an air conditioning system.
In a manner not illustrated here, the webs include unheated conductors, which connect the heating conductors of the individual flexible heat exchanger elements 10. In principle, the unheated webs 14 have the same structure as the individual flexible heating elements 10, whereby they can be manufactured in one and the same work process. This allows simultaneous manufacture of a plurality of flexible heating elements 10 together with the necessary unheated webs 14 in the same process. After the manufacturing process in flat position, as shown in FIG. 2 a, the heat exchanger elements 10 are bent around the respective webs 14, as is shown in FIG. 2 b. This results in a stack of planar heat exchanger elements, which can for instance be inserted in a pipe conduit.
Advantageously, the planar heat exchanger elements 10 each can have a different width, which is not illustrated here in greater detail. As a result, they are adapted better to the interior of the pipe. As is for instance indicated in FIG. 2 c, the flexible planar heat exchanger elements 10 can be connected with heat exchanging bodies 16, which dissipate the heat through convection to the surrounding medium, e.g. air. In addition, there can also be provided heat exchanging ribs, which cannot be seen in FIG. 2 c. The cooling bodies, in particular in the form of ribs, can at the same time be used as supports for the flexible planar heat exchanger elements. This provides for a very compact construction.

Claims

1. An air heat exchanger in air diffuser systems, comprising flexible planar heat exchanger elements, wherein the individual planar heat exchanger elements are connected with each other by means of webs.

2. The air heat exchanger as claimed in claim 1, wherein the air heat exchanger is coupled in an aircraft.

3. The air heat exchanger as claimed in claim 1, wherein the webs are made of a flexible, bendable material.

4. The air heat exchanger as claimed in claim 1, wherein the webs have a structure that is the same as the planar heat exchanger elements.

5. The air heat exchanger as claimed in claim 1, wherein the planar heat exchanger elements have a variable design in terms of shape, size and heat exchanger performance.

6. The air heat exchanger as claimed in claim 1, wherein the planar heat exchanger elements have a variable heat exchanger performance along their length, in order to achieve a uniform surface temperature in the direction of the traversed length.

7. The air heat exchanger as claimed in claim 1, wherein the planar heat exchanger elements are connected with additional heat exchanging bodies.

8. The air heat exchanger as claimed in claim 7, wherein the additional heat exchanging bodies are shaped in a form of plates and/or ribs.

9. The air heat exchanger as claimed in claim 1, wherein the planar heat exchanger elements constitute plates.

10. The air heat exchanger as claimed in claim 1, wherein the additional heat exchanging bodies are used as supports and as spacers for the planar heat exchanger elements.

11. A method for manufacturing an air heat exchanger in air diffuser systems comprising fabricating a plurality of individual planar heat exchanger elements and a plurality of webs connecting the individual planar heat exchanger elements as an integral element.

12. The method as claimed in claim 11, wherein sensors for monitoring the temperature as well as their connecting lines are integrated into the planar heat exchanger elements during the fabricating process.

13. The method as claimed in claim 11, wherein the planar heat exchanger elements are first manufactured in a flat position together with the webs connecting the same and are then bent into a final shape and possibly inserted into a pipe conduit.

14. The method as claimed in claim 11, further comprising using said air heat exchanger as an air heater to heat air in an aircraft.

15. The method as claimed in claim 11, wherein said individual planar elements are flexible.

16. An air heat exchanger in air diffuser systems, comprising:

a plurality of flexible planar heat exchanger elements, and

a plurality of webs connecting the individual planar heat exchanger elements, wherein the air heat exchanged is coupled in an aircraft.

17. The air heat exchanger as claimed in claim 16, wherein the webs are made of a flexible and bendable material, and wherein the webs have a structure that is the same as the planar heat exchanger elements.

18. The air heat exchanger as claimed in claim 16, wherein at least two planar heat exchanger elements have a variable shape, size and heat exchanger performance.

19. The air heat exchanger as claimed in claim 18, wherein at least two planar heat exchanger elements have a variable heat exchanger performance along their respective lengths, in order to achieve a uniform surface temperature in the direction of the traversed length.

20. The air heat exchanger as claimed in claim 19, wherein at least one planar heat exchanger element and one web are integrally formed, the exchanger further comprising a plurality of sensors for monitoring the temperature as well as corresponding connecting lines, said sensors further being integrally formed into the planar heat exchanger elements.