DE4416936C2 - Heater for a vehicle or aircraft - Google Patents

Description

The invention relates to a heating device for a vehicle or aircraft according to the preamble of claim 1.

In particular in motor vehicles with internal combustion engines, the heating of the Required heat by recovering part of the passenger compartment Engine exhaust gases contain heat in particular the internal combustion engine downstream heat exchangers generated.

In a well-known motor vehicle (Porsche 911 Turbo, model year 1991) is for everyone Exhaust line a separate exhaust gas / air heat exchanger is provided, each Heat exchanger seen in the flow direction of the exhaust gas flow - before Catalyst or a turbocharger of the exhaust system is attached, namely in Area of an exhaust manifold connected to the internal combustion engine. Of the Heat exchanger encases a portion of the exhaust manifold and becomes air flows through. This installation position ensures that the heating air through the relatively hot Exhaust gas flow is heated sufficiently. A disadvantage of this installation position of the Heat exchanger, however, is that the exhaust gas through the heat exchanger heat is withdrawn, so that in the event of a cold start the catalyst takes longer to reach the required operating temperature is reached and starts.

The US 4,146,176 shows a heating device for a vehicle with a Internal combustion engine and an exhaust system containing a catalyst, wherein the heat exchanger switched on there in the exhaust system - in the flow direction of the Exhaust gas flow seen - after the catalyst is arranged in the exhaust line.

The heat exchanger used is not area-wise as the exhaust system surrounding exhaust gas / air heat exchanger, but according to the heat pipe principle educated.

The object of the invention is, on an air heating device for a vehicle or aircraft, with an internal combustion engine and one Exhaust system containing catalyst to take such precautions that on the one hand the heating air supplied to the interior has a sufficient temperature and that on the other hand the response behavior of the catalyst - especially with a Cold start - is improved.

According to the invention, this object is achieved by the characterizing features of Claim 1 solved. Further, the invention in an advantageous manner Features contain the subclaims.  

The main advantages achieved with the invention are that by arranging an exhaust gas / air heat exchanger - in the flow direction of the Exhaust gas flow seen - after the catalyst at a sufficient temperature the heating air an improved response behavior of the catalyst, in particular during a cold start.

A particularly advantageous embodiment is given when an after the catalyst arranged, relatively large volume Exhaust gas / air preheater and a relative installed in front of the catalytic converter small-volume exhaust gas / air main heat exchanger is provided.

The small main heat exchanger means that the exhaust gas flow is only a small one The amount of heat withdrawn, which means that the catalyst has a higher rate at an early stage Temperature reached and starts up sooner.

The preheater provided after the catalytic converter has no influence on the light-off behavior of the catalyst and can therefore be of any size be designed. The arrangement of a Exhaust gas values are improved after the heat exchanger after the catalytic converter.

The arrangement according to the invention can be used for all internal combustion engines Use air heating, i.e. for naturally aspirated, turbo and diesel engines.

An embodiment of the invention is shown in the drawing and will explained in more detail below:

It shows:

Fig. 1 is an oblique perspective rear view of a vehicle with a rear-side air-cooled internal combustion engine and an air-side heater for the passenger compartment,

Fig. 2 is a top view of the exhaust system

Fig. 3 is a perspective oblique view from the front of an exhaust system and a heater

Fig. 4 is a block diagram of part of the exhaust system and the preheater

Fig. 5 shows a unit X of Fig. 4 on a larger scale

Fig. 1 shows a system constituted by a passenger car vehicle 1, which has in the rear area an air-cooled internal combustion engine 2. The internal combustion engine 2 has two rows of cylinders 3 arranged in a boxer arrangement. A multi-port exhaust manifold 4 of an exhaust system 5 is led away from each row of cylinders 3 , the exhaust manifold 4 being brought together into a single connecting piece on the side facing away from the internal combustion engine 2 .

Referring to FIGS. 2 and 3, a supercharged internal combustion engine 2 is shown, in each of the two strands 6, 7 of the exhaust system 5, a turbocharger 8 is arranged adjacent to the exhaust manifold. 4 An exhaust manifold 9 leads from each turbocharger 8 to a downstream catalytic converter 10 , which is connected via a further exhaust manifold 11 to an end silencer 12 . The exhaust gases pass from the rear silencer 12 through an end pipe 13 into the open. However, there is the possibility that only one train with a single catalytic converter 10 is led away from the internal combustion engine 2 (for example in the case of in-line engines).

A heating device 14 for heating the heating air supplied to an interior 15 comprises at least one exhaust gas / air heat exchanger for each line 6 , 7 of the exhaust system 5 . According to the invention, the exhaust gas / air heat exchanger is arranged downstream of the catalytic converter 10 , as seen in the flow direction of the exhaust gas stream.

In the exemplary embodiment of the exhaust system are for each strand 6, 7, 5 are provided two gas / air heat exchanger 16,17, namely - viewed in the flow direction of the exhaust gas flow - is arranged downstream of the catalyst 10 preheat exchanger 16 and an attached upstream of the catalyst 10 the main heat exchanger 17th In Fig. 3 only the two exhaust gas / air heat exchangers 16 , 17 of the one line 6 of the exhaust system 5 are shown, whereas only the heat exchanger 16 is shown from the second line 7 .

The preheater 16 can be of relatively large volume and surrounds the exhaust manifold 11 running between the catalytic converter 10 and the muffler 12 in a partial area. The preheat exchanger 16 is shown in FIG. 5 is formed by a single- or multi-shell member 18 that surrounds the exhaust manifold 11 and having an air inlet opening 19 and an air outlet opening 20.

The main heat exchanger 17 is preferably of relatively small volume and is formed by a casing of the exhaust manifold 4 .

In the rear area, the cold air is drawn in from the outside of the vehicle by a cooling air blower 20 and / or an auxiliary blower 21 and reaches a heating manifold 22 which is connected to the two preheat exchangers 16 via connecting pieces 23 . As a result, the air is preheated and reaches the main heat exchanger 17 via connecting pieces 24 , where the heating air is heated further.

From each main heat exchanger 17 , the hot air passes forward through hot air ducts 25 to a heating and air-conditioning device 26 arranged in the area of the dashboard.

A differential flap (not shown in more detail) is arranged locally within each hot air duct 25 , through which hot air can be discharged to the outside if necessary.

The warm air ducts 25 run in sections within the side sills 27 on the outside and have local silencers 28 .

The arrangement of the exhaust gas / air heat exchanger 16 , 17 according to the invention can be used for all internal combustion engines with air heating, that is to say for naturally aspirated, turbo and diesel engines. The heater 14 is applicable to automobiles, airplanes, forklifts, or the like.

In principle, an arrangement of the exhaust gas / air heat exchanger is also included water-cooled internal combustion engines possible.

The arrangement of the exhaust gas / air heat exchanger can also be on only one Exhaust system take place.

The exhaust gas / air heat exchanger can also be used alone (without the main heat exchanger) be provided after the catalyst.

Claims (3)

1. Heating device for a vehicle or aircraft with an internal combustion engine and at least one exhaust gas / air heat exchanger switched on in the exhaust system for heating the heating air supplied to an interior, the exhaust system comprising at least one catalyst, characterized in that the heating device ( 14 ) for each Exhaust system of the exhaust system ( 5 ) comprises two exhaust gas / air heat exchangers ( 16 , 17 ), the first exhaust gas / air heat exchanger forming a preheater ( 16 ), which - as seen in the flow direction of the exhaust gas stream - is arranged after the catalytic converter ( 10 ) , and that the subsequent second exhaust gas / air heat exchanger forms a main heat exchanger ( 17 ) which is arranged upstream of the catalytic converter ( 10 ) in the flow direction of the exhaust gas stream. 2. Heating device according to claim 1, characterized in that the preheater ( 16 ) and the main heat exchanger ( 17 ) are connected to one another via a connecting pipe. 3. Heating device according to claims 1 and 2, characterized in that the main heat exchanger ( 17 ) is of relatively small volume, whereas the preheater ( 16 ) has a relatively large volume.