Power System Cold-Start Control for Exhaust Pressure and NOx
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Solution Overview
Problem
Existing power systems face challenges in controlling exhaust gases to ensure optimal operating conditions for exhaust aftertreatment systems, particularly during cold starts, which can lead to high emissions and inefficient engine performance.
Innovation Solution
A method involving a throttle arrangement and exhaust gas recirculation paths with controlled valves to manage exhaust gas counterpressure and nitrogen oxide levels, combined with temperature-based initiation of starting procedures, ensures appropriate engine load and emissions control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the power system starts without controlled exhaust gas recirculation, then the starting process is simpler, but nitrogen oxide emissions increase and exhaust aftertreatment system performance deteriorates
Solution Approach 1:
The system performs preliminary actions by detecting ambient temperature and determining whether to initiate a cold starting procedure before actual engine operation begins. The computer system pre-configures the throttle arrangement and exhaust gas recirculation path valve based on temperature conditions, ensuring optimal emissions control is ready before combustion starts, thereby preventing high nitrogen oxide emissions from the outset.
Solution Approach 2:
The system implements feedback control by continuously monitoring ambient temperature and adjusting the throttle arrangement and exhaust gas recirculation path valve accordingly. The computer system receives temperature information, processes it through evaluation logic, and dynamically modifies exhaust gas flow paths to maintain nitrogen oxide levels within target ranges, creating a closed-loop control system that adapts to changing conditions.
2Ease of operation
If the throttle arrangement is kept open during cold start, then engine loading is reduced for easier starting, but exhaust gas counterpressure becomes uncontrolled and aftertreatment system performance suffers
Solution Approach 1:
The system applies dynamics by making the throttle arrangement controllable with variable positioning rather than fixed open or closed states. The computer system dynamically adjusts the throttle arrangement to specific positions within target exhaust gas counterpressure ranges during cold starting procedures, allowing real-time optimization of both engine starting ease and exhaust gas pressure control based on ambient conditions and engine response.
Solution Approach 2:
The system changes parameters by adjusting the throttle arrangement position to maintain exhaust gas counterpressure within specific target ranges. The computer system modifies the physical state of the exhaust gas flow by controlling throttle opening degrees, thereby changing pressure parameters to simultaneously facilitate easy engine starting and ensure proper aftertreatment system operation during cold conditions.
3Object-generated harmful factors
If exhaust gas recirculation is activated during cold start, then nitrogen oxide emissions are reduced, but the control system complexity increases
Solution Approach 1:
The exhaust gas recirculation path valve serves multiple functions: it controls nitrogen oxide emissions during cold starts, regulates exhaust gas flow to maintain counterpressure, and adapts to different ambient temperature conditions. The computer system integrates this single valve into a universal control strategy that handles various operating scenarios, reducing the need for additional specialized components while achieving comprehensive emissions control.
Data Source
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AI summary
A computer system (6) configured to: receive temperature information (TI) indicative of a temperature (Tamb) of air ambient of a power system (4) comprising an internal combustion engine (10), and in response to determining that the temperature information (TI) indicates a temperature (Tamb) of air ambient of the power system (4) being equal to or below a threshold temperature, issue information to the power system (4) to initiate a cold starting procedure comprising the following: - controlling the throttle arrangement (32) throttling exhaust gas from said internal combustion engine to a turbine wheel (20) of a turbo (14), such that an exhaust gas counterpressure upstream the throttle arrangement (32) is within a target exhaust gas counterpressure range (ΔPexhaust), and - controlling the first exhaust gas recirculation path valve (56) such that an amount of nitrogen oxides in exhaust gases emitted from the internal combustion engine (10) is within a target nitrogen oxides amount range (ΔNOx, target).