Multifuel Engine Fuel Injection Control via Pressure Threshold Switching
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Solution Overview
Problem
Two-fuel internal-combustion engines face irregular operations during fuel transitions due to delays in pressure regulation of gaseous fuels, leading to deviations in fuel injection, which are costly to address with separate electronic control units.
Innovation Solution
A method for controlling fuel injection in a multifuel internal-combustion engine using a single electronic control unit with a switching device and sensors to optimize fuel switching during specific engine phases, ensuring accurate fuel injection by determining the ideal moment for switching based on engine conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single common electronic control unit is used to control both injector assemblies, then device complexity and cost are reduced, but the ability to independently control each fuel type is limited
Solution Approach 1:
The control unit is segmented into two distinct control circuits: a first control circuit for controlling the liquid fuel injector assembly and a second control circuit for controlling the gaseous fuel injector assembly. This segmentation allows each fuel type to be controlled independently while using a single physical control unit, thus reducing device complexity while maintaining adaptability.
Solution Approach 2:
The control unit dynamically switches between controlling different fuel types based on operating conditions. The switching device alternates connection between the first and second injector assemblies to the common output, enabling the system to adapt to different fuel requirements while using shared hardware resources.
2Manufacturing precision
If fuel injection control is maintained during pressure jumps, then injection precision is improved, but irregular operations occur during rapid torque transitions
Solution Approach 1:
The control unit detects pressure jumps in the gaseous fuel supply line and preemptively counteracts their harmful effects by adjusting the injection command. When a pressure jump is detected, the control unit modifies the injection timing or duration to compensate for the impending pressure variation, preventing irregular operations before they occur.
Solution Approach 2:
The system uses pressure sensors to provide real-time feedback on gaseous fuel pressure conditions. The control unit continuously monitors pressure variations and adjusts the injection control accordingly, creating a closed-loop control system that maintains injection precision while preventing irregular operations during rapid transitions.
3Stability of the object's composition
If the pressure regulator responds quickly to flowrate variations, then fuel pressure stability is improved, but mechanical inertias cause delayed response
Solution Approach 1:
The control unit performs preliminary actions by detecting trends in fuel consumption and anticipating pressure variations before they occur. When a rapid increase in torque demand is detected, the control unit pre-adjusts the injection parameters to compensate for the expected pressure drop, allowing the system to respond faster than the mechanical pressure regulator alone could achieve.
Data Source
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AI summary
A method for controlling fuel injection in a multifuel internal-combustion engine (1) that can inject alternatively a liquid fuel and a gaseous fuel; the control method envisages the steps of: injecting the gaseous fuel by means of at least one corresponding injector (15); cyclically measuring the pressure (Prail) of the gaseous fuel within the common channel (22); determining at least one upper-limit threshold (Prail-min; Prail-max) for the pressure (Prail) of the gaseous fuel within the common channel (22); comparing the pressure (Prail) of the gaseous fuel within the common channel (22) with the upper-limit threshold (Prail-min; Prail-max); and carrying out an automatic fuel switch from the gaseous fuel to the liquid fuel when the pressure (Prail) of the gaseous fuel within the common channel (22) exceeds the upper-limit threshold (Prail-min; Prail-max).