Gas Engine EGR Mass Flow Determination Using Temperature Sensors
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Solution Overview
Problem
Existing gas engines with exhaust gas recirculation (EGR) systems face challenges in accurately and cost-effectively determining the air mass flow and recirculated exhaust gas mass flow due to the sensitivity of air mass meters to interference, making it difficult to control these parameters simultaneously.
Innovation Solution
The implementation of temperature sensors in the intake tract upstream and downstream of the exhaust gas mixing area, in conjunction with a measuring device and a control unit, allows for the reliable and cost-effective determination of recirculated exhaust gas and air mass flows, eliminating the need for air mass meters and enabling precise control through a closed loop system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an air mass meter is used to measure air mass flow in gas engines with EGR, then the air mass flow can be determined, but the measurement becomes very susceptible to interference and dirt
Solution Approach 1:
The patent extracts the measurement function from the air mass meter and implements it using temperature sensors combined with volumetric efficiency models. Instead of relying on a single vulnerable measurement device, the solution separates the measurement into multiple components (temperature measurement at different locations, volumetric efficiency calculation) that are more robust to interference and dirt.
Solution Approach 2:
The patent makes temperature sensors serve multiple functions: they measure intake air temperature, recirculated exhaust gas temperature, and enable calculation of both air mass flow and exhaust gas mass flow. This multi-functionality replaces the specialized air mass meter with more versatile and reliable temperature sensing.
2Reliability
If cooled and regulated exhaust gas recirculation is implemented to compensate for efficiency loss, then emission regulations can be met, but the complexity of the system increases
Solution Approach 1:
The patent implements feedback control by using measured temperatures and calculated mass flows to regulate the EGR system. The control unit continuously monitors temperature measurements from multiple sensors, calculates the actual air and exhaust gas mass flows, and adjusts the EGR system accordingly to maintain optimal operation and meet emission regulations.
Solution Approach 2:
The patent changes the operating parameters of the EGR system from fixed or simple control to dynamic control based on calculated mass flows and temperatures. By continuously adjusting EGR rates based on real-time measurements and volumetric efficiency models, the system optimizes emission compliance while managing complexity through intelligent control rather than mechanical complexity.
3Reliability
If temperature sensors are used instead of air mass meters to determine mass flows, then cost and reliability improve, but additional temperature sensors are required
Solution Approach 1:
The patent makes temperature sensors serve multiple functions: they measure intake air temperature, recirculated exhaust gas temperature, and enable calculation of both air mass flow and exhaust gas mass flow. This multi-functionality reduces the need for specialized measurement devices while maintaining reliability.
Solution Approach 2:
The patent enables the temperature sensors and control unit to self-determine the mass flows through volumetric efficiency models and temperature measurements, eliminating the need for external air mass meters. The system uses its own existing sensors and computational capabilities to perform measurements that would otherwise require additional specialized equipment.
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 method provides a reliable and cost-effective means to determine and control the recirculated exhaust gas and air mass flows, improving the accuracy and efficiency of gas engine operation by eliminating interference issues and allowing for precise adjustment based on current engine modes and parameters.
Implementation Method 1
at least one temperature sensor is arranged in addition to the measuring device both in the exhaust gas recirculation and in the intake tract upstream of the exhaust gas mixing area
Data Source
Figure 1
AI summary
The invention relates to an internal combustion engine, in particular a gas engine, for a vehicle, in particular for a commercial vehicle, with an intake manifold (25) by means of which a gas, in particular a fuel gas-air-exhaust gas mixture, can be supplied to a combustion unit (11), in particular a cylinder-piston unit, of the internal combustion engine (1), and with an exhaust gas recirculation system (2) by means of which exhaust gas of the combustion unit (11) can be supplied to the gas supplied to the combustion unit (11) at an exhaust gas mixing area (18), wherein at least one measuring device (22, 27) is arranged in the intake manifold (25) upstream of the combustion unit (11) and downstream of the exhaust gas mixing area (18), by means of which the gas mass flow, in particular fuel gas-air-exhaust gas mass flow, and the gas temperature, in particular fuel gas-air-exhaust gas temperature, can be determined.According to the invention, in particular for determining a recirculated exhaust gas mass flow (14) and/or an air mass flow (3) supplied to the combustion unit (11), at least one temperature sensor (29, 31) is arranged in addition to the measuring device (22, 27) both in the exhaust gas recirculation (2) and in the intake tract (25) upstream of the exhaust gas mixing area (18).