摘要:
A metal honeycomb body is disposed within a jacket member. At least partly structured sheet-metal layers are wrapped around one another and extend alternatingly back and forth in a curved, preferably involute, fashion between an outer annular region and an inner annular region of the honeycomb body. The sheet-metal layers form loops. At least three reversal lines are defined in the outer annular region, and the sheet-metal layers are intertwined about these reversal lines. A method for producing the honeycomb body includes the following steps: forming or winding a multi-layer hollow coil from at least one sheet-metal strip which has at least partial structuring; deforming the multi-layer hollow coil from the outside thereof towards the inside at at least three lines such that the at least one sheet-metal strip extends in loops between outer and inner reversal lines; and compacting the resulting deformed multi-layer structure about the inner reversal lines by rotationally intertwining the loops formed by the folded sheet-metal layers in a given direction.
摘要:
A method for producing a honeycomb body includes the following steps: forming or winding a multi-layer hollow coil from at least one sheet-metal strip which has at least partial structuring; deforming the multi-layer hollow coil from the outside thereof towards the inside at at least three lines such that the at least one sheet-metal strip extends in loops between outer and inner reversal lines; and compacting the resulting deformed multi-layer structure about the inner reversal lines by rotationally intertwining the loops formed by the folded sheet-metal layers in a given direction.
摘要:
A metal honeycomb body is disposed within a jacket member. At least partly structured sheet-metal layers are wrapped around one another and extend alternatingly back and forth in a curved, preferably involute, fashion between an outer annular region and an inner annular region of the honeycomb body. The sheet-metal layers form loops. At least three reversal lines are defined in the outer annular region, and the sheet-metal layers are intertwined about these reversal lines. A method for producing the honeycomb body includes the following steps: forming or winding a multi-layer hollow coil from at least one sheet-metal strip which has at least partial structuring; deforming the multi-layer hollow coil from the outside thereof towards the inside at at least three lines such that the at least one sheet-metal strip extends in loops between outer and inner reversal lines; and compacting the resulting deformed multi-layer structure about the inner reversal lines by rotationally intertwining the loops formed by the folded sheet-metal layers in a given direction.
摘要:
A method for analyzing a condition of at least one partial volume of a catalytic converter through which a gas mixture flows, includes measuring a temperature with a sensor at least at one location or in a region within a partial volume during a change of chemical and/or physical properties of the gas mixture. The location or the region and a configuration of the sensor are selected in such a way that a reaction of the measured temperature to a change of the properties of the gas mixture is at least approximately representative of a reaction of the temperature in the partial volume of the catalytic converter. Set point values are determined for the respective change in the properties of the gas mixture on the basis of a thermodynamic model while taking physical boundary conditions and properties of the partial volume into account. The reaction of the measured temperature is determined and compared with the set point values.
摘要:
A catalytic converter has an inner region and a jacket surface surrounding the inner region and being disposed approximately parallel to a given flow direction. The inner region conducts a flow of a fluid containing ingredients to be converted in the inner region by a catalyzed exothermic reaction. The flow passes through the inner region in the given flow direction. The reaction zone is defined as a part of the inner region in which a reaction predominantly takes place. A method for detecting a reaction zone in the catalytic converter includes detecting the reaction zone by measuring a distribution of temperature over the jacket surface along a measurement path being aligned approximately parallel to the given flow direction. The reaction zone is determined by a segment of the measurement path at which the temperature deviates by less than a predetermined limit value from a maximum value of the temperature over the measurement path.
摘要:
A method for monitoring catalytic activity of a catalytic converter through which exhaust gas can flow in an exhaust system of an internal combustion engine includes measuring a temperature at least at two temperature measuring sensors and periodically repeatedly determining a temperature measuring variable from signals issued by the sensors during operation of the engine with an engine monitoring system. According to one method, the sensors are spaced apart in flow direction in or near the catalytic converter, the temperature measuring variable is averaged over a sufficiently long period of engine operation to average out special strains and form a mean temperature value, catalytic activity is ascertained by comparing the mean temperature value with a predetermined limit value, and a report is issued if the mean temperature value does not correspond to the limit value. According to another method, the sensors are associated with the catalytic converter, further measuring variables characterizing an applicable operating state of the engine are determined, a temperature limit value is determined from the further measuring variables, catalytic activity is determined by comparing the temperature measuring variable with the temperature limit value, and a report is issued if the temperature measuring variable is lower than the temperature limit value.
摘要:
A method for operational monitoring of a catalytic converter of an exhaust system of an engine includes selecting at least two measurement locations at three-dimensionally spaced-apart cross-sectional regions of the exhaust system, and defining at least a partial volume of the catalytic converter between the locations being definitive for catalytic conversion of pollutants in the exhaust gas. The temperature at the regions is measured and monitored and the temperature at least at one of the locations is measured integrally over an approximately representative portion of at least one region and not spotwise. An apparatus for operational monitoring includes at least two temperature sensors disposed successively in flow direction in at least two regions of the exhaust system, defining at least the partial volume of the catalytic converter. At least one of the sensors integrally measures temperature over an approximately representative portion of the region in which it is disposed. An electronic monitoring apparatus evaluates measured temperature values. A display apparatus displays an evaluation outcome. A catalytic converter includes at least partially structured sheet-metal layers. At least one sensor is integrated into one of the structured sheet-metal layers in at least one cross-sectional region near at least one end surface, for integrally measuring temperature over an approximately representative portion of the one region.
摘要:
A method for monitoring catalytic activity of a catalytic converter through which exhaust gas can flow in an exhaust system of an internal combustion engine includes measuring a temperature at least at two temperature measuring sensors and periodically repeatedly determining a temperature measuring variable from signals issued by the sensors during operation of the engine with an engine monitoring system. Further measuring variables characterizing an applicable operating state of the engine are determined, a temperature limit value is determined from the further measuring variables, catalytic activity is determined by comparing the temperature measuring variable with the temperature limit value, and a report is issued if the temperature measuring variable is lower than the temperature limit value.
摘要:
A method for analyzing a condition of at least one partial volume of a catalytic converter through which a gas mixture flows, includes measuring a temperature with a sensor at least at one location or in a region within a partial volume during a change of chemical and/or physical properties of the gas mixture. The location or the region and a configuration of the sensor are selected in such a way that a reaction of the measured temperature to a change of the properties of the gas mixture is at least approximately representative of a reaction of the temperature in the partial volume of the catalytic converter. Set point values are determined for the respective change in the properties of the gas mixture on the basis of a thermodynamic model while taking physical boundary conditions and properties of the partial volume into account. The reaction of the measured temperature is determined and compared with the set point values.
摘要:
A catalytic converter is connected downstream of an internal combustion engine of a motor vehicle and has at least a short portion to be quickly electrically heated. A method for controlling the heating of the catalytic converter includes turning on electric heating only after a delay after starting the internal combustion engine, if a rate of temperature change in the heatable portion of the catalytic converter, being caused by heat contained in exhaust gases of the internal combustion engine, is no greater than approximately a rate of temperature change attainable by electric heating.