Exhaust Gas Heating Device with Pyrolysis Reactor and Throttle Valve
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Solution Overview
Problem
Existing exhaust gas treatment systems for combustion engines face challenges in quickly and efficiently heating the exhaust gases to the required temperature for effective nitrogen oxide reduction, especially during cold starts, due to high electrical power requirements and potential damage to the pyrolyser reactor.
Innovation Solution
The exhaust gas channel incorporates a main flow channel and a bypass with an adjustable throttle valve, where the bypass flows into a device with two pyrolyser reactors. This setup reduces installation space and uses an internal gas-tight channel to feed the bypass mass current to the pyrolysis reactors, eliminating external piping and allowing for faster heating without radiation heat.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the entire reaction chamber is electrically heated to heat the pyrolysis reactor to a temperature level at which oxidation of the introduced fuel can occur automatically, then the exhaust gas can be heated effectively, but very high electrical power is required and very high currents can cause damage to the honeycomb structure and electrical connection
Solution Approach 1:
The patent applies preliminary action by pre-heating only the inlet region of the pyrolysis reactor where fuel evaporation occurs, rather than heating the entire reaction chamber. This is achieved through a localized heating element positioned at the inlet, which prepares the fuel for oxidation without requiring very high electrical power to heat the whole reactor volume.
Solution Approach 2:
The patent implements local quality by providing heating only in the specific region where it is most needed - the inlet zone where fuel evaporation and initial oxidation occur. This localized approach concentrates thermal energy where it generates the most benefit while minimizing overall power consumption and avoiding damage to other reactor components.
2Temperature
If the fuel evaporates and reacts exothermically in the pyrolysis reactor with an oxygen portion of the exhaust gas mass flow, then a sufficiently high temperature for pyrolysis is provided, but the mass flow of exhaust gas through the reactor must be carefully controlled
Solution Approach 1:
The patent applies dynamics by using an adjustable throttle valve that can dynamically control the exhaust gas mass flow through the pyrolysis reactor based on operating conditions. This dynamic control allows the system to optimize the balance between fuel evaporation rate and oxygen availability, maintaining stable exothermic reactions across varying engine loads and temperatures.
3Adaptability or versatility
If a bypass is arranged parallel to the exhaust system to direct a partial mass flow through the heating device, then the device can be integrated into the exhaust system, but large installation space is required
Solution Approach 1:
The patent implements the nested doll principle by integrating the pyrolysis reactor and heating device within the existing exhaust system structure. The reactor is positioned to utilize the exhaust flow path without requiring a completely separate parallel bypass, thereby reducing the overall installation space while maintaining the ability to direct partial mass flow through the heating device.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enables quick and effective heating of the exhaust system, maintaining temperatures above 200°C for efficient SCR system operation, while reducing installation space and minimizing the risk of pyrolyser reactor damage.
Implementation Method 1
fuel evaporates and reacts exothermically at least partially in the pyrolysis reactor
Implementation Method 2
fuel evaporates and reacts exothermically at least partially in the pyrolysis reactor with an oxygen portion of the exhaust gas mass flow introduced into the pyrolysis reactor by oxidation
Implementation Method 3
fuel evaporates and reacts exothermically at least partially in the pyrolysis reactor
Implementation Method 4
fuel can be decomposed into shorter carbon chains through pyrolysis
Implementation Method 5
fuel can be decomposed into shorter carbon chains through pyrolysis
Implementation Method 6
exhaust duct has at least one main flow duct and a bypass as well as an adjustable throttle valve in the main flow duct
Data Source
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AI summary
The invention relates to an exhaust gas channel (1) for guiding the exhaust gas of an internal combustion engine, wherein the exhaust gas channel (1) has at least one main flow channel (11) and a bypass (12) as well as an adjustable throttle valve (3) in the main flow channel (11), wherein the throttle valve (3) is pivotable from an open position in which the main flow channel (11) is released and a closed position in which the main flow channel (11) is blocked, wherein the bypass (12) opens into a device (2) for exhaust gas heating with at least one pyrolysis reactor (26), into which at least a partial mass flow of the exhaust gas of the internal combustion engine is introduced via the bypass (12), wherein at least one fleece (22) is connected upstream of the pyrolysis reactor (26), which is supplied with fuel.wherein the fuel evaporates and reacts exothermically, at least partially, in the pyrolysis reactor (26) with an oxygen fraction of the exhaust gas mass flow introduced into the pyrolysis reactor (26) by oxidation, in particular to provide a sufficiently high temperature for pyrolysis, wherein the exhaust gas heated by means of the device (2) is introduced downstream of the device (2) into the main flow channel (11) for exhaust gas heating, wherein the bypass (12) opens into an inlet chamber (21), wherein two pyrolysis reactors (26) are connected downstream of the inlet chamber (21), which are in particular arranged symmetrically to the exhaust gas channel (1).