Engine Airflow Control via Dual Valve Segmentation
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Solution Overview
Problem
Gas engine devices experience issues with abnormal combustion due to rapid throttle valve closure during no-load conditions and delayed air flow rate control when switching from low to high load, leading to imbalances in supercharging pressure and air-to-fuel ratios.
Innovation Solution
The engine device incorporates a main throttle valve and an air supply bypass valve, with load-dependent control strategies to manage air flow rates accurately, using sensors to adjust valve openings based on engine load and pressure differences, ensuring optimal air-to-fuel ratios and preventing surging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the throttle valve opening degree is rapidly reduced during no-load state, then the output of the engine is rapidly reduced, but the supercharging pressure is abnormally increased causing surging and abnormal combustion
Solution Approach 1:
The air flow control is segmented into two independent pathways: main throttle valve for primary control and bypass flow path for supplementary control. This segmentation allows the bypass valve to compensate for pressure fluctuations caused by rapid throttle closure, preventing surging while maintaining fast response capability.
Solution Approach 2:
The bypass valve acts as an intermediary element between the throttle valve and the compressor inlet. By providing an alternative air flow path, it mediates the pressure imbalance caused by rapid throttle closure, preventing abnormal combustion while enabling quick output reduction.
2Power
If the throttle valve control is used to increase intake air for high load, then the air flow rate control has delay, but the fuel gas injection amount can be increased immediately
Solution Approach 1:
The bypass valve is positioned to enable preliminary air flow adjustment before the main throttle valve responds fully. When high load is demanded, the bypass valve can open to provide immediate air flow increase, reducing the delay caused by main throttle valve mechanics and ensuring air-to-fuel ratio balance.
3Productivity
If a single throttle valve is used to control air flow, then the device complexity is low, but the responsiveness and precision of air flow rate control is insufficient
Solution Approach 1:
The air flow control function is divided between two valves: main throttle valve for primary regulation and bypass valve for rapid adjustment and pressure stabilization. This segmentation enhances control responsiveness and precision while keeping each valve relatively simple in structure.
Solution Approach 2:
The bypass valve serves multiple functions: it provides alternative air flow path during rapid load changes, compensates for pressure fluctuations, and assists the main throttle valve in achieving precise air flow control. This multi-functionality justifies the added complexity by delivering superior control performance.
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 solution provides precise control over air flow rates, stabilizes engine operations, and prevents abnormal combustion by maintaining balanced air-to-fuel ratios, especially during load changes, thereby enhancing responsiveness and efficiency.
Implementation Method 1
a supercharger that compresses the air by means of the exhaust gas from the exhaust manifold
Implementation Method 2
an intercooler that cools the compressed air compressed with the supercharger and supplies the compressed air to the intake manifold
Data Source
Figure 1
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AI summary
Regarding an engine device including a supercharger, it is an object to provide the engine device that can execute the control of an air flow rate with excellent responsiveness with respect to variation in load. An engine device 21 of the present invention of the instant application executes the control of the opening degree of the main throttle valve V1 when engine load is in a low load area. In contrast, when the engine load is in a medium-to-high load area, an engine control device 73 sets a main throttle valve V1 to a predetermined opening degree and executes the control of the opening degree of an air supply bypass valve V2. In the medium-to-high load area on which variation in load exerts great influence, bypass valve control with excellent responsiveness is executed, so that the severe deficiency of the flow rate of the air can be suppressed with respect to the variation on load, and the engine device 21 can be smoothly operated.