DE102008010949A1 - Pipe arrangement for fuel cell system - Google Patents

Abstract

Aluminum tubes are to be used in the anode circuit of a fuel cell system. A pressure sensor (12) is to be connected to the aluminum tubes, wherein a connecting element (22) to which the pressure sensor (12) is connected can be heated by a heating device (24) so that interfering ice melts at correspondingly cold ambient temperatures and thus a cold start of the fuel cell system can be made possible. In order that the heat generated by the heater (24) actually heats the pressure sensor (12) and is not dissipated, the connection element (22) is thermally insulated from the metal tube (10), e.g. B. by a plastic plate (28) between the connection element (22) and metal tube (10) is arranged.

Description

The The invention relates to a piping arrangement according to the preamble of claim 1.

A such piping arrangement is used in a fuel cell system used, for. B. in the so-called anode circuit. With a metal pipe a connection element is coupled to which a sensor can be connected is or is connected. The connection element, usually referred to as "sensor port" is conventionally by forming a T-piece in the piping arrangement provided, wherein the connection element for enabling the connection of a sensor usually a thread having. usually will be to the connection element Pressure sensor connected.

At the Operation of a fuel cell system can be in the piping arrangement Apply water, just in the area of the connection element. When appropriate In cold ambient temperatures, the condensed water can freeze and thereby affect the function of the sensor or completely to make impossible. For example, a pressure sensor must be over the connection element with the interior of the metal pipe of the piping arrangement in Stand for the pressure of the at all can measure the metal pipe of conducted gas. The ice can have a corresponding opening in the connection element that leads to the pressure sensor, or also close an opening in the pressure sensor itself.

Man manages to provide a heater on the connection element. Before starting up the fuel cell system, the heater may cause the ice to melt. The provision of such a heater is for example in the JP 2005164538 A described.

The previous arrangement works satisfactorily when the metal tube Made of stainless steel. The heater can then the pressure sensor heat up to 100 ° C. This can be a blockage of the pressure sensor are lifted by ice, a cold start of the Fuel cell system is therefore not hindered.

you now wishes, in the anode cycle of fuel cell systems To use aluminum tubes. However, it has been shown that at Use of aluminum pipes in a pipeline arrangement according to the preamble of claim 1, the heater no longer works effectively.

It The object of the invention is a cold start of a fuel cell system even if allow a piping arrangement is used with aluminum tubes.

The Task is by a piping arrangement with the features according to claim 1 and a fuel cell system with such a piping arrangement for the passage of gas according to claim 10 solved.

According to the invention the connecting element with respect to the metal tube thermally isolated.

The Invention is based on the finding that the aluminum tube the derived from the heater heat dissipates too well. Measurements have shown that without the provision of a thermal Isolate the pressure sensor only to a temperature of 65 ° C can be warmed up, what a de-icing is not enough.

at A preferred embodiment of the invention is between Connection element and metal tube arranged a plastic material, because plastic is typically very poor heat-conducting.

The Plastic material may be provided in the form of a plastic plate be. A plastic plate can be well made of Teflon or Produce polyphenylene sulfide, which are particularly good thermal insulation.

Instead of a plastic plate can also be between connection element and metal tube a thermally insulating foam can be arranged. This can a shape in the connection area to be influenced. Foam is also easy to prepare.

After all The plastic material can even be provided directly in the form of a plastic pipe section be - the connection element is then directly on this Plastic pipe section arranged and no longer on the metal pipe. The metal tube thus goes into the plastic pipe section with the Connection element and the plastic pipe section in turn then again in a metal tube over.

at Use in the anode loop, the plastic pipe in the plastic pipe section for making a conductive connection between the one and the other metal pipe covered with a metal be: a thin metal layer impaired a thermal insulation is not.

The Invention can be used in any metal tubes, wherein a necessity of using the invention Idea as shown above, if the metal tube made of aluminum is formed.

The Invention may be in connection possibilities for any sensors are used. As shown above arises the problem is exacerbated when one on the connection element connected sensor is a pressure sensor, the one with a Interior of the metal pipe in communication connection Entrance has.

In a fuel cell system, the piping arrangement on the cathode side are used, but the main application in An anode cycle takes place.

Hereinafter, a preferred embodiment of the invention will be described with reference to the drawing, wherein 1 a section through a piping arrangement according to an embodiment of the invention shows.

A piping arrangement comprises a metal pipe 10 , A pressure sensor 12 intended to pressure one through the metal tube 10 Measure conducted gas. This is in a section of the metal tube 10 in which the in 1 Cut shown is an opening 14 provided via the gas from the interior of the metal tube 10 into an interior 16 of the pressure sensor 12 can reach where the actual measuring device of the sensor 12 is housed (which in 1 not shown).

The pressure sensor 12 includes a foot 18 made of metal and a head 20 made of plastic, between which the interior 16 is formed. At the foot 18 a thread is formed by means of which the pressure sensor 12 in a connection element 22 can be screwed (a so-called sensor port), which in turn with the metal tube 10 connected is. The connection element 22 is through a heater 24 heated. When in an opening 26 of the foot 18 of the pressure sensor 12 Condensation has accumulated, which is frozen to ice, the heater can 24 a melting of this ice effect, thus the interior 16 of the pressure sensor 12 again in communication with the interior of the metal tube 10 is brought. Also the rest of the pressure sensor 12 is by the heater 24 heated. This is a commissioning of the pressure sensor 12 even in cold weather conditions. In particular, when using the piping arrangement in a fuel cell system, a pressure sensor 12 Deliver reliable readings immediately after a cold start.

The metal pipe 10 should in this case be made of aluminum. So that by the heater 24 generated heat does not over the metal tube 10 drains off, but the pressure sensor 12 heats up, is between the connection element 22 and the metal tube 10 a plastic plate 28 arranged, which consists for example of Teflon or polyphenylene sulfide and O-rings 30 . 30 ' opposite the connection element 22 or the metal tube 10 is sealed. In 1 are no fasteners shown, but it goes without saying that the connecting element 22 by suitable connecting elements together with the plastic plate 28 on the metal tube 10 must be attached, for example, suitable bolts can be used outside of the cut.

10

metal pipe

12

pressure sensor

14 26

openings

16

inner space

18

foot

20

head

22

connecting element

24

stoker

28

Plastic plate

30 30 '

O-rings

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• JP 2005164538 A [0004]

Claims (11)

Pipe arrangement with a metal pipe ( 10 ) and one with the metal tube ( 10 ) coupled connection element ( 22 ) to which a sensor ( 12 ) is connectable or connected, wherein in or on the connection element ( 22 ) a heating device ( 24 ), characterized in that the connecting element ( 22 ) opposite the metal tube ( 10 ) is thermally isolated. Pipe arrangement according to claim 1, characterized in that between connecting element ( 22 ) and metal tube ( 10 ) Plastic material is arranged. Pipe arrangement according to claim 2, characterized in that the plastic material in the form of a plastic plate ( 28 ). Pipe arrangement according to claim 2 or 3, characterized characterized in that the plastic material comprises Teflon. Pipe arrangement according to one of the claims 2 to 4, characterized in that the plastic material polyphenylene sulfide includes. Pipe arrangement according to claim 1 or 2, characterized characterized in that between connecting element and metal tube thermally insulating foam is arranged. Pipe arrangement according to claim 2, characterized in that the pipe arrangement has a pipe section which consists at least partially of plastic and to which the connecting element ( 22 ) connected. Pipe arrangement according to one of the preceding claims, in which the metal pipe ( 10 ) is formed of aluminum. Pipe arrangement according to one of the preceding claims, in which a to the connection element ( 22 ) connected sensor a pressure sensor ( 12 ), one with an interior of the metal tube ( 10 ) in communication connected input ( 26 ) having. Fuel cell system with the piping arrangement according to any one of the preceding claims for passing of gas. Fuel cell system according to claim 10, characterized characterized in that the piping arrangement in the anode circuit is provided.