Webasto Ag Fahrzeugtechnik

Webasto-werk W. Baier Gmbh & Co.

Webasto Fahrzeugtechnik

Dieter Goerlich

Rainer Kolodzie

Friedrich Widemann

Dieter Raethel

Ruediger Galtz

Rainer Reiter

Wilfried Meiler

Roland Fiola

Alois Reichensdoerfer

A process and a device for closed-loop and open-loop control of the output of a burner, particularly a burner operated with exhaust gas from an internal combustion engine as an oxygen source for the regeneration of a particle filter unit, in which the burner output is controlled as a function of the average pressure of the internal combustion engine and/or the speed of the engine. Additionally, the temperature between the outlet side of the burner and the particle filter unit can also be entered as a closed-loop variable for closed-loop control. In the device, an open-loop and closed-loop output control device is provided, which receives, as inputs, the temperature, detected by a temperature sensor, and, optionally, the average medium pressure detected by an accelerator sensor, and/or the speed of the internal combustion engine detected by a speed sensor. The temperature sensor is placed downstream from the burner in the exhaust gas section. The output of the open-loop and closed-loop output control device is connected to a fuel quantity control device, by which the amount of fuel or the amount of mixture fed to the burner is controlled.

Process and device for closed-loop and open-loop control of the output

The invention relates to a high performance burner whose performance can be controlled in a stepless manner. To this end, a premixing chamber is upstream of a burner nozzle that extends into a combustion chamber. Fuel is supplied in controllable amounts to the premixing chamber, and a mixture, in the form of an emulsion, is prepared therefrom by means of air supplied from an auxiliary air line. The air-fuel mixture thus prepared is passed to the burner nozzle which diffuses it in the combustion chamber. A high performance burner in accordance with the invention is designed for use as a heating device of high performance, like an independent heating device but, advantageously, can be employed as an exhaust gas afterburner, whereby the high performance burner is disposed in an exhaust gas line of a combustion engine, or a branch line thereto. The afterburning of the exhaust gases being usable for generating of heat by way of an exhaust gas heat exchanger, as well as for the regeneration of soot filters in combustion engines, particularly Diesel combustion engines.

High performance burner

A burner for difficult to combust gas mixtures, particularly those including exhaust gases of an internal combustion engine, that is preferably intended for the regeneration of particle filter units in the exhaust gas duct of an internal combustion engine, such as a diesel internal combustion engine. For initiating the regeneration of such so-called soot filter units, the burner generates hot combustion gases at the outlet thereof. The burner includes, at a distance from the discharge opening of a fuel injection nozzle, a baffle barrier that extends approximately perpendicular to the center axis of the fuel injection nozzle. This baffle barrier divides the combustion chamber into an energy-rich zone with a gas mixture prepared to be ignitable and a second zone in which the exhaust gas from the internal combustion engine is diverted. In this way, the burner can also burn even difficult to combust gas mixtures and can reliably maintain, regardless of the operation conditions of the internal combustion engine, a flame in the combustion chamber for generating hot combustion gases.

Burner for difficult to combust gas mixtures

A soot filtering unit in the exhaust gas system of a diesel internal combustion engine that includes at least two parallel soot filters. For regeneration, a regeneration device, having at least one burner and control flap, is provided upstream from the soot filters of the soot filtering unit. The burner(s) provided in the soot filtering unit supplies high temperature gases for the regeneration of the soot filters, and exhaust gas from the exhaust gas pipe is fed thereto as an oxygen carrier for the combustion process. According to a first embodiment, a single burner is provided for all soot filters to be regenerated and the burner does not lie directly in the pipes of the exhaust gas pipe that conveys exhaust gas to the soot filters. Preferably, exhaust gas is supplied to the burner(s) through separate exhaust gas feed pipes but, alternatively, a separate burner can be located directly in each branch of the exhaust pipe upstream of the respective soot filter provided therein. In the latter case, the burner can be supplied directly by a predetermined amount of exhaust gas being permitted to leak past the control flaps when they are closed.

Soot filtering unit for the exhaust of a diesel internal combustion

A burner for hard-to-ignite mixtures, such as with exhaust gases of an internal combustion engine, in which an ignitable mixture is prepared in a locally limited area for producing an ignition flame that is then used for igniting the hard-to-ignite mixture. According to one embodiment, the burner has an auxiliary ignition burner that is integrated into the actual burner and that is operated with compressed air, which is delivered either by a vehicle compressed air system or by a separately provided air compressor. In an alternative embodiment, air is fed in, additionally, by an air injection device to an outlet area of the fuel nozzle and in the vicinity of the ignition device to prepare an extremely ignitable mixture in this area, which is used to generate an ignition flame. The air injection device can be supplied with compressed air in the same manner as for the auxiliary ignition burner in the first embodiment. Alternatively, ambient air with sufficient oxygen content can be fed in through the air injection device.

Burner for hard-to-ignite mixtures

A soot-filtering unit for an exhaust section of a diesel internal combustion engine with a supercharging device. The soot-filtering unit has at least on soot filter in an exhaust line and a regeneration device for the soot filter which includes at least one burner. The configuration of the unit connects an air intake of the burner of the regeneration device to the supercharging device so that the burner is supplied with a portion of the air charge from the supercharging device of the diesel internal combustion engine. In this connection, the configuration can be done in such a way that the burner is supplied exclusively with air from the air charge produced by the supercharging device, or so that the burner is supplied with a mixture of air from the air charge and exhaust gas from the exhaust gas line. The invention enables the burner of the regeneration device to always be reliably ignited, irrespective of engine performance characteristics, without requiring additional devices, and the construction expense for such a soot-filtering unit can be reduced. Multifilter systems, such as double-filter systems, which have either a single burner as a regeneration device or separate burners, are possible in accordance with various embodiments. Furthermore, operation of the burner is possible either exclusively with air charge from the supercharging device or with a mixture of exhaust gas and air charge in the multifilter systems, as well.

Soot-filtering unit for the exhaust gas section of a diesel internal

A process for operating an exhaust gas burner that can be used particularly in the regeneration of soot filters or the like, in which the exhaust gas burner is turned on to start the regeneration or the like only if the oxygen content in the exhaust gas has a sufficiently high value to readily support ignition. For this determination, recourse is, preferably, had to the instantaneous values of engine performance characteristics reflective of the presence of a high oxygen content in the exhaust gas, e.g., a low engine speed and/or low average pressure valve of the engine. For the determination, the accelerator position and/or the revolutions per minute of the internal combustion engine can be monitored. In the device, a control device is connected, upstream from the turning-on device of the exhaust gas burner, that activates the turning-on device only if the oxygen content in the exhaust gas has a sufficiently high value. For this purpose, the control device can be connected to a detection device that obtains appropriate data from sensors for predetermined engine-operation parameters.

Process and device for operating an exhaust gas burner

A process for operating a fuel-operated heater, in which the instantaneous operating condition of the heater is determined according to appropriate criteria and the maximum producible heating power is adjusted according to it. The instantaneous operating condition of the heater is used as the control value for instantaneous maximum producible heating power to optimize the yield of the heating power of the heater without exceeding safety limits, especially component safety limits. Further, an arrangement for performance the process has a detection device, such as a sensor for determination of a characteristic component temperature, which works together with an adjustment device for adjusting the instantaneous maximum producible heating power. This adjustment device controls the fuel feed device of the heater by an actuator and appropriately changes the amount of fuel fed to the burner of the heater. Additionally, the amount of combustion air fed to the burner can, optionally, be appropriately changed.

Process for operating a fuel-operated heater and control arrangement for

An exhaust gas unit, for multicylinder diesel internal combustion engines with at least one particulate filter and a regeneration device, in which at least four particulate filters are placed parallel to one another in branches of at least one exhaust gas pipe. Thus, in the exhaust gas unit of such a multicylinder diesel internal combustion engine, several small particulate filters can be used that can be produced at resonable cost. At the same time operating safety is increased, since when one of the parallel filters falls or during regeneration of one of them, the operation of the internal combustion engine can continue essentially unimpeded, so that a vehicle equipped with such an internal combustion engine can continue to be operated. With such a design of an exhaust gas unit, a regeneration device in the form of a burner that preferably can be operated by exhaust gases from the exhaust gas unit can be assigned to each pair of filters. Alternatively, a single, common regeneration device in the form of a burner can be provided for all parallel filters of the exhaust gas unit. Such an exhaust gas unit can be advantageously used for a multicylinder diesel internal combustion engine of the V type as well as of the in-line type.

Exhaust gas unit for multicylinder diesel internal combustion engines

In an exhaust gas pipe of a diesel engine, a particle separator serving for reduction of the particle emission of the diesel engine by exhaust gas aftertreatment, a burner by which the particle separator can be regenerated by means of hot fuel gases delivered by the burner unit, the burner unit is so placed that, even in the case of leaks occurring at a flap valve for shutting off of the fuel gas line, no impairment of the operation of the burner is to be feared. For this purpose, upstream from the burner, a blower may be installed, which constantly provides air to the burner unit and the space of the fuel gas line between the flap valve and the burner unit, the air being discharged from the space into the environment by a vent pipe. In this way, exhaust gases, which leak past the closed flap valve into the fuel gas line, do not reach the burner and are discharged by the vent pipe into the enviroment. Alternatively, a suction blower can be placed in a vent pipe branching off from the space between the flap valve and the burner unit in the fuel gas line, this blower causing venting of the space, when the separator is not being regenerated and the flap valve is closed. According to another alternative embodiment, a bypass pipe goes from the space between the flap valve and the burner unit, into a section of the exhaust gas pipe located downstream from the separator. The discharge area of this bypass pipe is designed as an injector or ejector, so that a negative pressure is produced in the bypass pipe by which the space in the fuel gas line is vented.

Particle separator arrangement in an exhaust pipe of a diesel engine

An intermediate housing that is, preferably, developed as a cast part and combines several functions and objectives in itself. The intermediate housing not only houses a driving motor for a combustion air blower and a heating air fan, but the driving motor is also disposed by means of a circumferential support developed in the intermediate housing which, at the same time, serves as a stop during the mounting. By means of an elastic bearing of the driving motor, structure-born noise transmission can be avoided. On one side, a combustion air intake connection piece, a fuel supply pipe receiving opening and an exhaust gas outlet connection piece are integrally formed. For the mounting of the heater at a mounting arrangement, the intermediate housing also has passages for fastening screws that are accessible from the direction of the top side of the heater. A receiving space, that is tightly closable by means of a cap, is provided for containing the electrical supply devices, and an ignition device and a flame detector are also housed in the receiving space. In addition, casing parts of the heater can also be fastened to the intermediate housing. At the outer surface of the intermediate housing, axially extending cooling ribs are formed that have an interrupted axial course and are circumferentially staggered with respect to one another.

Intermediate housing for a fuel-operated heater

For a heater operated by means of liquid fuel, a vaporization burner is provided that has a large-volume active first vaporization part for the very volatile components of the fuel and a large-surface second vaporization part for the least volatile fuel components. The two vaporization parts are separated from one another by a fuel-impermeable material, such as ceramics, so that any occurring coke formations at the second passive vaporization part cannot migrate to the first vaporization part. As a result, the operating reliability and the service life of such a vaporization burner are improved.

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Emmering, Germany

Dieter Goerlich