Combustion Gas Conditioning for CVS Exhaust Measurement
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Solution Overview
Problem
Existing systems for conditioning intake air for internal combustion engines struggle to maintain consistent and dynamic control, especially under varying operating conditions, leading to poor control quality and increased complexity in engine test bench setups, particularly in geodetic and climatic challenging locations.
Innovation Solution
A method and device that provide a substantially constant, fully conditioned combustion gas supply exceeding the maximum engine requirement, with adjustable pressure control and humidity/temperature conditioning after setting a predeterminable pressure setpoint, allowing for integration with Constant Volume Sampling (CVS) full-flow systems without dilution, and incorporating all engine openings and sensors for enhanced regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the volume or mass flow of combustion gas is increased to exceed the maximum engine requirement, then the control dynamics are improved and oscillations are avoided, but the system complexity and energy consumption increase
Solution Approach 1:
The system dynamically adjusts the volume or mass flow of combustion gas based on real-time engine requirements and operating conditions. The control system modifies the combustion gas flow rate dynamically, allowing the system to respond to changing engine demands while maintaining stability and avoiding oscillations throughout the entire operating range.
Solution Approach 2:
The invention changes the parameters of combustion gas delivery by adjusting volume or mass flow rates according to engine operating conditions. By varying these parameters dynamically rather than maintaining a fixed flow rate, the system achieves improved control dynamics while adapting to different engine loads and operational states.
2Reliability
If the combustion gas flow rate is dynamically adjusted to follow engine changes, then the control quality improves, but the system complexity and response time requirements increase
Solution Approach 1:
The control system continuously monitors engine operating parameters and uses this feedback to adjust the combustion gas flow rate. By implementing a feedback mechanism that tracks engine changes in real-time, the system maintains high control quality and adaptability without requiring overly complex control architecture, as the feedback loop naturally coordinates the response.
3Measurement precision
If the combustion gas is conditioned upstream of the CVS system, then the measurement accuracy improves, but exhaust gas dilution occurs
Solution Approach 1:
The system segments the combustion gas flow into separate paths: one path delivers conditioned combustion gas to the engine, while another path directs a portion of the combustion gas downstream of the CVS system where it mixes with exhaust gases for measurement. This segmentation allows conditioning to occur without diluting the exhaust sample, as the mixing occurs after the measurement point.
Solution Approach 2:
The invention introduces an intermediary approach by using a separate combustion gas path that acts as a mediator between the conditioning system and the exhaust measurement system. This intermediary path allows the combustion gas to be conditioned without directly interfering with the exhaust gas composition at the measurement point, thereby maintaining measurement accuracy while still providing beneficial conditioning effects.
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 approach ensures reliable and accurate exhaust gas measurement by maintaining consistent air conditions, reducing system complexity, and enabling smaller, cost-effective conditioning systems, while avoiding exhaust gas dilution and oscillations, thus enhancing control dynamics and measurement accuracy.
Implementation Method 1
adjustment of a predeterminable pressure setpoint for the combustion gas
Implementation Method 2
humidity and/or temperature conditioning
Implementation Method 3
humidity and/or temperature conditioning
Data Source
Figure 1~2
AI summary
In a method for measuring exhaust gases in combustion engines, preferably in test benches, using CVS full-flow systems, the exhaust gas of the combustion engine is mixed with combustion gas, preferably air, and the volume or mass flow rate of the combustion gas is determined by the CVS full-flow system. This mass flow rate exceeds the maximum quantity required by the combustion engine.In order to enable the use of CVS full-flow systems with increased control dynamics without significant impact on the overall control system, and to avoid dilution of the engine exhaust gases upstream of the CVS full-flow system, a substantially constant, fully conditioned quantity of a moist and/or temperature-conditioned combustion gas is supplied to the combustion engine at all times, whereby this quantity is at least equal to the maximum quantity required by the combustion engine, and unused combustion gas is routed to the CVS full-flow system, and a predefinable pressure setpoint for the combustion gas upstream of the CVS full-flow system and also upstream of the combustion gas conditioning is regulated.Alternatively, a substantially constant, fully conditioned quantity of a moisture- and/or temperature-conditioned combustion gas can be supplied to the CVS full-flow system at any time, with fully conditioned combustion gas being drawn off from the CVS full-flow system for the combustion engine upstream of the mixing area.