DOC Regeneration Control via Two-Stage Temperature Increase
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Solution Overview
Problem
Existing diesel oxidation catalyst (DOC) regeneration control devices fail to reliably recover the DOC from blockage states or blockage risk states, leading to fuel efficiency deterioration and potential heat damage to the diesel particulate filter (DPF) due to inadequate temperature management during forced regeneration.
Innovation Solution
A regeneration control device that detects blockage states or risk states in the DOC and executes a two-stage temperature increase process, first activating the DOC to a first temperature and then increasing it to a second temperature, typically around 400°C, to remove adhering substances while minimizing hydrocarbon discharge and preventing blockage progression, using early-post injection with a fuel injection device to execute both processes without additional temperature units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the DOC temperature is increased to remove adhering substances, then the DOC blockage is reduced, but hydrocarbon discharge increases and fuel consumption increases
Solution Approach 1:
The temperature increase process is divided into two distinct stages: a first temperature increase process that activates the DOC to a first temperature, and a second temperature increase process that further increases the temperature to a second temperature for removing adhering substances. This segmentation allows the system to minimize hydrocarbon discharge during the first stage while effectively removing blockage in the second stage, thereby reducing overall fuel consumption compared to a single high-temperature process.
Solution Approach 2:
The first temperature increase process is performed as a preliminary action to activate the DOC before the second temperature increase process. By activating the DOC first, the catalyst is prepared to handle the subsequent high-temperature process more efficiently, reducing unwanted hydrocarbon discharge during the main cleaning operation and optimizing fuel usage.
2Reliability
If the DOC temperature is increased to activate the catalyst, then the oxidation performance improves, but the risk of heat damage to the DPF increases
Solution Approach 1:
The temperature increase is segmented into two controlled stages with distinct temperature levels and durations. The first stage activates the DOC at a moderate temperature, while the second stage removes adhering substances at a higher but controlled temperature. This segmentation prevents excessive temperature exposure that could damage the DPF, while still achieving the necessary oxidation performance.
Solution Approach 2:
The system changes temperature parameters dynamically through two distinct processes: first increasing to a first temperature for activation, then increasing to a second temperature for removing adhering substances. By controlling the temperature profile rather than maintaining a constantly high temperature, the system achieves effective oxidation while minimizing heat damage risk to the DPF.
3Device complexity
If a single temperature increase process is used, then the device complexity is reduced, but the DOC cannot be reliably recovered from blockage states
Solution Approach 1:
The temperature control process is segmented into two distinct processes: a first temperature increase process for activating the DOC and a second temperature increase process for removing adhering substances. This segmentation enables reliable DOC recovery from blockage states by addressing different aspects of the blockage problem at different temperature levels, while the control device manages this complexity through coordinated execution of the two processes.
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
Effectively recovers the DOC from blockage states or risk states, reduces fuel consumption, and prevents blockage progression, thereby improving fuel efficiency and reducing the risk of heat damage to the DPF.
Implementation Method 1
the temperature of the non-combusted fuel increases by oxidizing the non-combusted fuel with a diesel oxidization catalyst (DOC)
Implementation Method 2
oxidizing the non-combusted fuel with a diesel oxidization catalyst (DOC) so that the temperature of the non-combusted fuel increases
Data Source
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AI summary
A regeneration control device controlling a temperature increase unit of an exhaust gas treatment device including a DOC disposed in an exhaust passage of a diesel engine to regenerate the exhaust gas treatment device includes: a DOC temperature-increase-necessary-state detection part detecting a temperature increase necessary state including at least one of a blockage state, detected on the basis of comparison between a blockage parameter related to blockage of the DOC and a predetermined blockage threshold, of the DOC or a blockage risk state, detected when the diesel engine is in an operating state that is likely to cause blockage of the DOC, of the DOC; and a DOC temperature increase execution part executing a DOC temperature increase control including: a first temperature increase process to control the temperature increase unit, if the temperature increase necessary state of the DOC is detected, so as to increase the temperature of the DOC to a first temperature at which the DOC activates; and a second temperature increase process to control the temperature increase unit after completion of the first temperature increase process so as to increase the temperature of the DOC to a second temperature higher than the first temperature.