US20030177759A1

US20030177759A1 - Apparatus for treatment of exhaust of a combustion device

Info

Publication number: US20030177759A1
Application number: US10/390,093
Authority: US
Inventors: Ian Faye; Martin Maier
Original assignee: Individual
Current assignee: Robert Bosch GmbH
Priority date: 2002-03-19
Filing date: 2003-03-17
Publication date: 2003-09-25
Also published as: GB0306197D0; FR2837404A1; DE10212021A1; GB2388058A; GB2388058B

Abstract

An apparatus (12) for treatment of exhaust gas of a combustion device (1) with a catalytically active converter unit (5) includes a heating device (5) for heating the converter unit (5) with a hydrogenous heating substance, which reduces substantially the system-related expenditure, and which substantially improves the cold-start behavior of the catalytic converter and therefore, substantially reduces in particular the contaminant exhaust of the combustion device (1) during its cold start phase. The combustion device (1) is formed as a supply device (1) for supplying the hydrogenous heating substance to the converter unit (5).

Description

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus for treatment of exhaust gas of a combustion device with a catalytically active converter unit.

According to the progressive state of knowledge, specifications for protection of health and the environment, which regulate the emissions of motor vehicles, have been completely tightened-up. For fulfillment of these specifications, for example, related to the use of correspondingly modified fuel, harmful exhaust components are removed from the exhaust by means of a catalytically active converter unit, a so-called catalyzer.

These catalyzers require, however, determined operating temperature conditions for fulfilling their function, which in particular, with the cold start of a corresponding combustion device, for example, a gas or diesel engine, are generally not provided.

Already in motor vehicles, for example, by means of heat development in the exhaust line before the catalyzer, the exhaust is heated with the starting process, and thereby, additionally or more quickly heats the catalytically active condenser plate of the catalyzer.

Also, engine-internal features are performed already in current motor vehicles, such as the change in blocking period, so that, in particular, by means of so-called “retarded ignitions”, hotter exhaust is produced, which subsequently flows through the catalytic converter and heats this more intensely. Likewise, flowing over the catalyzer with rich exhaust upon blowing in of secondary air is already known, whereby the increased reaction rate of combustible gases with oxygen again heats the exhaust, and therewith, indirectly the catalyzer.

In addition, it is known that corresponding catalyzers can be heated particularly quickly by supplying hydrogen.

These already-known devices for heating of the exhaust or catalyzer, however, are relatively expensive, lead to an increased, disadvantageous use of fuel, and/or have disadvantageous thermal resistances.

SUMMARY OF THE INVENTION

In contrast, an object of the present invention is to provide an apparatus for the treatment of exhaust of a combustion device with a catalytically active converter unit, whereby a heating device for heating the converter unit with a hydrogenous heating substance is provided, which substantially reduces the system-related expenditure, and which markedly improves the cold-start behavior of the catalyzer and, thereby substantially reduces the contaminant exhaust of the combustion device during its cold-start phase.

This object is solved by the apparatus of the present invention of the above-described type.

Correspondingly, the inventive apparatus shows that at least the combustion device is formed as a supply apparatus for supplying the hydrogenous heating substance to the converter unit.

With the assistance of the inventive structure of the combustion device as a supply apparatus, the already-provided exhaust line is useable as a line for supplying the hydrogenous heating substance or fuel to the converter unit. Correspondingly, the additionally necessary, separate supply line for supplying the hydrogenous heating substance to the converter unit, as in the prior art, is eliminated. A proportionally long supply line is necessary, as is customary, since the converter unit in general, in particular, with motor vehicles, is spaced apart from the combustion device. On this basis, the constructive expenditure for supplying the hydrogenous heating substance to the converter unit is reduced, so that a particularly effective and cost-effective embodiment of the present invention is realizable.

Advantageously, in contrast to the “normal” operating manner of the combustion device, an ignition, in particular, in the cylinder, is prevented, since otherwise, the hydrogen contained in the heating substance is converted, and thereby, for heating of the converter unit, the hydrogen is no longer as warm, or is only as warm, for disposition.

According to the present invention, the combustion device can be formed advantageously as a “passive” supply apparatus, whereby the supply apparatus makes possible a flowing-through of the hydrogenous heating substance through the combustion device to the converter unit. It is also possible that intake and outlet valves or the like are simultaneously opened, so that the preferably pressurized heating substance can flow through at least one cylinder or the like.

Likewise, the combustion device can be formed in an advantageous manner as an “active” supply apparatus, whereby this, for example, is provided as a pump or the like to active through-pumping of the hydrogenous heating substance to the converter unit. For example, in this embodiment of the invention, in particular with the use of a lifting cylinder engine, the hydrogenous heating substance can be suctioned with a suction cycle and is supplied to the converter unit, or the catalyzer, in a discharge cycle. In this manner, the flow-through is carried out in an advantageous manner by means of corresponding coordination of the closing or opening of the valves. With this variation, the invention can be directed possibly at a separate pressurizer for the supplying of the heating substance to the converter unit. This reduces the structural expenditure in an advantageous manner.

Basically, an advantageous, electric control unit can be provided, in consideration of other apportioning elements for control, such as valves, spark plugs, reservoirs, compression ratios and the like. For example, by means of advantageous sensors, at least one operating parameter of the converter unit and/or the combustion device, such as, for example, a temperature or the like, is determined and the control unit for controlling the entire combustion assembly is regulated.

Preferably, at least one supply element for supplying the heating substance is arranged in the flow direction before the combustion device. In this manner, it is possible that in a particularly simple manner, the hydrogenous heating substance of the combustion device is able to be supplied.

In a preferred manner, the supply element has at least two supply connections for supplying the heating substance and a fuel of the combustion device. By using a corresponding supply element with at least two supply connections, in an advantageous manner, no additional elements are required, or already-provided valves or the like, with only minimal modifications according to the invention, can be used.

In this connection, with the assistance of this variation, the use of already-provided standard components, for example, so-called “bi-fuel injection valves” (BFE) is possible. Corresponding “bi-fuel injection valves”, in particular, those the Applicants have used to this point, for example, for supplying the fuel and for supplying of a starting fuel for the combustion device are used. Likewise, a relatively low-boiling, carbon-hydrogen containing starting fuel and/or an easily boiling hydrogenous starter fuel is used.

In this manner, improvement of the exhaust emissions by means of corresponding starter fuel, above all, during the cold-start phase of the combustion device can be achieved.

According to the present invention, during a heating phase of the converter unit, that is, from starting to reaching a specific operating temperature or until expiration of a determined time, the combustion device is used as a supply device for supplying the hydrogenous heating substance to the converter unit. Preferably, in particular with the assistance of the control unit, a heating phase of the combustion device can be provided. In this manner, advantageously, ignition of the fuel to be supplied, hydrogenous heating substance, or a mixture of the heating substance and fuel to be supplied is possible.

According to a particular variation of the invention, a possible pressurized reservoir storage for preparation of the hydrogenous heating substance is provided. Likewise, this can be refillable. Alternatively, or in combination herewith, in a preferred embodiment of the invention, at least one generator, or production unit, for production of the hydrogenous heating substance is provided. With the assistance of this generator, a corresponding reservoir storage can be completely eliminated or can dimensioned substantially smaller, without impairing the preparation of the hydrogenous heating substance. Preferably, the geneartor produces the hydrogenous heating substance in a particular operating phase.

Advantageously, the generator is formed as an electrolysis unit. In this manner, it is possible that by means of the electrolysis of water or the like through an electric current, the hydrogenous heating substance can be produced. Water as the output material for the electrolysis has qualities that are particularly advantageous to environmental and safety concerns, as well as relatively low costs. The electrical current required for electrolysis, for example, can be applied during a particular operating phase of the electrolysis unit, in which, in particular, a light machine of the combustion device and/or likewise an electrical energy storage medium can be used advantageously.

Preferably, the electrolysis unit is formed as a membrane electrolysis unit, in which common, commercial standard components are useable and the hydrogenous heating substance can be produced, for example, under a pressure of up to 30 bar. Advantageously, in this manner, the hydrogenous heating substance likewise can be supplied merely by means of opening and closing of at least one check valve, or apportioning device, such as, for example, a valve or the like, of the combustion device or the converter unit.

Above all, alternatively to using the electrolysis unit, a reformer unit or the like can be provided for production of the hydrogenous heating substance for at least partially converting in an advantageous manner the fuel or combustion fuel of the combustion device. Likewise, already known reforming-cleaning substances, such as shift units or the like, can be provided for increasing the hydrogen portion on the reformer. In this manner, an apportioned input of hydrogen-containing and carbon-monoxide-containing reformer can improve significantly the behavior of the combustion device in specified operating states, for example during a cold start and/or full-load phase.

Advantageously, at least one storage element for storage of the hydrogenous heating substance is provided. Preferably, the storage element is formed particularly for intermediate storage of the produced hydrogenous heating substance. For example, during the operation of the combustion device, the hydrogenous heating substance can be produced with the produced energy, without dynamic fuse time, and preferably, can be stored intermediately with the storage element. Likewise, the heating substance can be produced in the so-called “best point” of the engine, or the production unit, with almost optimal efficiency, and possibly can be stored intermediately, for example, in the idling of the engine.

In an advantageous embodiment of the invention, at least one pressurizer for pressurizing the hydrogenous heating substance is provided. For example, the hydrogenous heating substance produced by the generator for intermediate storage can be impinged with pressure in the storage element with a membrane pump or the like.

For using the hydrogenous heating substance according to the invention, the pressurized heating substance can be supplied without proportionally large energy use for improving the cold-start behavior of the converter unit and/or the combustion device. Likewise, the reservoir storage, or the storage element, can be filled before the first start of the combustion device with hydrogenous heating substance. Preferably, the reservoir storage is formed similarly to the storage element.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic block diagram, showing a combustion engine with a fuel tank, a light machine or generator, a battery or accumulator, and a catalyzer. [0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

One embodiment of the invention is illustrated in the drawing and will next be described with reference to this single FIGURE. [0029]
In FIG. 1, a [0030] combustion engine 1 with a fuel tank 2, for example, a gas or diesel tank, a so-called light machine 3, or generator, a battery 4, or accumulator, and a catalyzer 5 are shown in schematic, block representation.
The [0031] light machine 3 is mechanically coupled by means of a connection 6 and produces electrical energy during the operation of the combustion engine 1, the electrical energy being supplied by means of a line 7 to the battery 4 and/or an electrolyzer 8, or other electrical consumers 9, for example, to air conditioning, to Infotainment, to seat adjustments, to automatic window lifters, and so forth.
The [0032] electrolyzer 8 can also be driven by means of electrical energy of the battery 4. The electrolyzer 8 converts water in a non-represented manner, in particular, into a hydrogenous fluid which, by means of lines 13 and 14, is supplied to a storage 10 and/or directly to the combustion engine 1 (not shown), and according to the invention, supplied further to the catalyzer 5. The line 13 has a pump for pressurizing the hydrogen.
The [0033] combustion engine 1, according to the invention, is controlled by means of a not-specifically illustrated electrical control unit, so that, for example, no fuel is burned in the combustion engine 1; rather, the hydrogenous fluid is sluiced through this in a chemically unaltered form. This hydrogenous fluid is supplied to the catalyzer 5 by means of an exhaust line 11 already provided in a common, commercial combustion assembly 12 or motor vehicle during its cold-start phase, so that the catalyzer's catalytically active condenser plate is heated up extremely quickly to the necessary operating temperature. In this manner, the cold-start behavior of the catalyzer as well as the entire combustion assembly 12 is significantly improved, and without realizing a large, constructive expenditure.
For example, upon starting of the [0034] combustion assembly 12, a starter, or so-called “ignition key”, is actuated and in a first, relatively short phase, the catalyzer 5 according to the invention is heated extremely quickly to the operating temperature by means of the supply of hydrogenous fluid, preferably from the storage 10 through the combustion engine 1. In contrast to the state of the art, this additional phase is not noticeable, or hardly noticeable, to the operator of the starter.
In a subsequent, second phase, preferably fuel is supplied from the [0035] fuel tank 2 to the combustion engine 1, whereby it is also contemplated alternatively to supply the hydrogenous heating substance to the combustion engine 1. Likewise, the supply of the hydrogenous heating substance can take place simultaneously with the supply of the fuel, whereby the exhaust of the combustion engine 1 is positively affected.
For supply of the hydrogenous fluid and/or the fuel, for example, commercially common standard components, such as the so-called “bi-fuel injection valves” can be used, so that no additional valve for supplying the hydrogenous fluid to the [0036] combustion engine 1 is necessary. In addition, in this manner, the control of corresponding components, or the realization of the desired operating phases, are controllable in an advantageous manner.
Basically, the emission from contaminant-containing exhaust is improved by the particularly simple, inventive supplying of the hydrogenous heating substance to the converter unit or to the [0037] catalyzer 5, in particular, during the cold-start phase of the combustion assembly 12. In this manner, proportionally strong exhaust threshold values of the time can be significantly under-exceeded.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above. [0038]
While the invention has been illustrated and described herein as an apparatus for treatment of exhaust of a combustion device, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. [0039]
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.[0040]

Claims

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. Apparatus (12) for treatment of exhaust of a combustion device (1) with a catalytically active converter unit (5), whereby a heating apparatus (5) for heating of the converter unit (5) with a hydrogenous heating substance is provided, characterized in that at least the combustion device (1) is formed as a supplying device (1) for supplying the hydrogenous heating substance to the converter unit (5).

2. Apparatus (12) according to claim 1, characterized in that at least one supply element for supplying the hydrogenous heating substance is disposed in a flow direction before the combustion device (1).

3. Apparatus (12) according to claim 2, characterized in that the supply element has at least two supply connections for supply the heating substance and a fuel of the combustion device (1).

4. Apparatus (12) according to claim 2, characterized in that the supply element is formed as an injection valve.

5. Apparatus (12) according to claim 1, characterized in that at least one generator (8) for production of the hydrogenous heating substance is provided.

6. Apparatus (12) according to claim 5, characterized in that the generator (8) is formed as an electrolysis unit (8).

7. Apparatus (12) according to claim 6, characterized in that the electrolysis unit (8) is formed as a membrane electrolysis unit (8).

8. Apparatus (12) according to claim 5, characterized in that the generator (8) includes at least one reformer unit for at least partially converting fuel.

9. Apparatus (12) according to claim 1, characterized in that at least one storage element (10) for storing the hydrogenous heating substance is provided.

10. Apparatus (12) according to claim 1, characterized in that a pressurizer (8) for pressurizing the hydrogenous heating substance is provided.

11. Apparatus (12) according to claim 1, characterized in that the converter unit is formed as a heating device.

12. Apparatus (12) according to claim 5, characterized in that an electrical control unit for controlling a supply element, the generator (8) or a pressurizer (8) and/or a storage element (10) is provided.

13. Vehicle with an apparatus (12) for treatment of exhaust of a combustion device (1), whereby a heating device (5) for heating of a catalytically active converter unit (5) with a hydrogenous heating substance is provided, characterized in that the device (12) is formed according to claim 1.

14. Method for treatment of exhaust of a combustion device (1) with a catalytically active converter unit (5), whereby a heating device (5) for heating of the converter unit (5) is used with a hydrogenous heating substance, characterized in that in a heating phase of the converter unit (5), the combustion device (1) is used as a supply device (1) for supplying the hydrogenous heating substance to the converter unit (5).

15. Method according to claim 14, characterized in that a device (12) as defined in claim 1 is used.