Heating apparatus comprising a thermoelectric device

Abstract

The invention relates to a heating apparatus ( 10 ) comprising a thermoelectric device with several thermoelement legs ( 20 ). A wall ( 12 ) and a heat exchanger ( 26 ) which are in contact with the thermoelement legs are configured in an electrically insulating manner while the thermal contact is established via electrically conductive layers ( 22 ) that interconnect the end zones of the thermoelement legs ( 20 ) as desired.

1 . A heating apparatus, comprising:
 a wall, the inside of which has adjoining it a region for the routing of hot exhaust gases,   a housing which at least partially surrounds the wall, a medium to be heated flowing through an interspace between the wall and the housing, and   a thermoelectric device which is arranged in the interspace and has a plurality of thermoelement legs and which is suitable for generating an electrical voltage on account of a temperature difference between the exhaust gases and the medium to be heated,   wherein the wall is designed to be at least partially electrically insulating, in that the thermoelement legs are fastened with a first end region, by means of electrically conductive layers), to a heat contact portion of the wall, in that an at least partially electrically insulating heat exchanger is provided, which is arranged opposite the heat contact portion of the wall, in that the thermoelement legs are fastened with a second end region, by means of electrically conductive layers, to the electrically insulating heat exchanger, and   in that the electrically conductive layers connect the respective end regions of the thermoelement legs at least partially to one another.   
   
   
       2 . The heating apparatus of  claim 1 ,
 wherein the wall is comprised of an electrically insulating ceramic having high thermal conductivity.   
   
   
       3 . The heating apparatus of  claim 1 ,
 wherein the electrically insulating heat exchanger consists at least partially of a ceramic having high thermal conductivity.   
   
   
       4 . The heating apparatus of  claim 2 ,
 wherein the ceramic for the wall and/or for the electrically insulating heat exchanger has aluminum nitride.   
   
   
       5 . The heating apparatus of  claim 1 , wherein the electrically conductive layers connect the thermoelement legs in series with one another. 
   
   
       6 . The heating apparatus  claims 1 , wherein the electrically conductive layers connect the thermoelement legs in parallel with one another. 
   
   
       7 . The heating apparatus of  claim 1 , wherein the electrically conductive layers connect groups of thermoelement legs in parallel with one another and connect these groups in series with one another. 
   
   
       8 . The heating apparatus of  claim 1 ,
 wherein the medium to be heated is liquid, in particular water, and   in that the heat contact portion lies opposite a flame tube end.   
   
   
       9 . The heating apparatus of  claim 8 ,
 further comprising an interspace, receiving the thermoelement legs between the wall and the electrically insulating heat exchanger is sealed off by means of a sealing device against the ingress of the liquid medium to be heated, and   in that the sealing device is suitable for compensating thermally induced expansions.   
   
   
       10 . The heating apparatus of  claims 1 ,
 wherein the medium to be heated is gaseous, in particular air, and   in that the heat contact portion lies in the region of an inlet for the gaseous medium to be heated.   
   
   
       11 . The heating apparatus of  claim 10 , further comprising an interspace, receiving the thermoelement legs, between the wall and the electrically insulating heat exchanger is protected by means of a windbreak against the ingress of the gaseous medium to be heated. 
   
   
       12 . The heating apparatus of  claim 1 ,
 wherein the thermoelectric device is supported on the housing via an elastic connection.   
   
   
       13 . The heating apparatus of  claim 1 ,
 wherein the thermoelectric device is supported on the housing via a heat exchanger and elastic means.   
   
   
       14 . The heating apparatus of  claim 1 ,
 wherein the thermoelectric device is supported on the housing via a heat exchanger and a plate supporting the heat exchanger and equipped with elastic means.   
   
   
       15 . The heating apparatus of  claim 14 ,
 wherein the heat exchanger and the plate equipped with elastic means are produced in one piece.   
   
   
       16 . The heating apparatus of  claim 1 ,
 wherein the elastic connection comprises cup springs.   
   
   
       17 . The heating apparatus of  claim 1 ,
 wherein a mechanical connection between the wall and the heat exchanger has a heat-insulating material.   
   
   
       18 . The heating apparatus of  claim 17 ,
 wherein the heat-insulating material contains aluminum oxide and/or mullite.   
   
   
       19 . The heating apparatus of  claim 17 ,
 wherein the connection between the first housing and the heat exchanger has a sealing device which is suitable for sealing off the thermoelectric device against the medium to be heated and for compensating thermally induced expansions.   
   
   
       20 . The heating apparatus of  claim 19 ,
 wherein the wall and the heat-insulating material and/or the sealing device are produced in one piece.   
   
   
       21 . The heating apparatus of  claim 19 ,
 wherein the heat exchanger and the heat-insulating material and/or the sealing device are produced in one piece.   
   
   
       22 . The heating apparatus  claim 1 ,
 wherein a heat conduction means is provided between the thermoelectric device and the wall and/or between the thermoelectric device and the heat exchanger.   
   
   
       23 . The heating apparatus of  claim 22 ,
 wherein the heat conduction means has a heat conduction paste.   
   
   
       24 . The heating apparatus of  claim 22 ,
 wherein the heat conduction means has a heat conduction foil.