Dual Fuel Engine Gas Flow Control for Tier 4 Emissions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Dual fuel engine systems face challenges in achieving precise and robust control to meet Tier 4 emissions regulations while minimizing diesel fuel usage and maximizing the use of less-expensive gas fuel, requiring advanced methods for determining engine parameters and adjusting fuel injection commands.
Innovation Solution
A method and system for controlling dual fuel engine systems that determine a gas flow target based on gas power, thermal efficiency, and lower heating value, adjusting for measured gas temperature or pressure, and using PID controllers to calculate base gas injector commands, ensuring optimal gas substitution rates and engine bank balancing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If gas fuel is used to replace diesel fuel in dual fuel engine systems, then operating costs are reduced and energy efficiency is improved, but precise control of gas injection becomes more difficult due to variations in gas temperature and pressure
Solution Approach 1:
The system performs preliminary actions by determining gas flow targets based on gas power targets and thermal efficiency estimates before actual injection, and by pre-calculating base gas injector commands using PID controllers. This advance preparation allows the system to account for gas properties and engine conditions before injection occurs, improving control precision despite gas temperature and pressure variations
Solution Approach 2:
The system implements feedback mechanisms by using measured gas temperatures and pressures to adjust gas flow targets, and by using gas substitution rate estimates to refine injector commands. The PID controllers continuously monitor and adjust injection parameters based on actual engine performance and gas properties, maintaining precise control despite variations in gas fuel characteristics
2Reliability
If advanced control methods are implemented to meet Tier 4 emissions regulations, then emission standards are met and engine protection is improved, but system complexity increases
Solution Approach 1:
The controller is designed with multi-functionality, serving as a central hub that performs diverse functions including determining gas flow targets, calculating base injector commands, adjusting for gas conditions, and monitoring engine parameters. This universal controller consolidates multiple control functions into a single device, managing complexity while providing comprehensive engine protection and emissions control
Solution Approach 2:
The system introduces intermediary elements such as the PID controller and gas flow target determination as mediators between the control system and the physical injection process. These intermediaries translate high-level control objectives into precise injection commands, managing the complexity of coordinating multiple control functions while ensuring reliable engine protection and emissions compliance
3Loss of substance
If gas substitution rate is maximized to reduce diesel fuel usage, then operating costs decrease, but control precision and engine bank balancing become more challenging
Solution Approach 1:
The control system segments the injection control by determining separate base gas injector commands for each engine bank using PID controllers. This segmentation allows independent optimization of each bank's injection parameters, maintaining precise control even at high gas substitution rates. The system can adjust each bank's commands based on its specific conditions, ensuring balanced performance while maximizing gas fuel usage
Solution Approach 2:
The system dynamically changes injection parameters including gas flow targets, base injector commands, and timing parameters based on real-time measurements of gas temperature, pressure, and engine performance. This adaptive parameter adjustment maintains precise control and optimal gas substitution rates by continuously optimizing injection parameters according to actual operating conditions
Data Source
AI summary
A method for controlling a dual fuel engine system includes determining a gas flow target for an internal combustion engine of the dual fuel engine system, where the gas flow target is based on a gas power target of the internal combustion engine, a thermal efficiency estimate of the internal combustion engine, and a lower heating value (LHV) within the internal combustion engine. The method also includes adjusting the gas flow target based on at least one of a measured gas temperature or a measured gas injector pressure and determining at least one base gas injector command based on the adjusted gas flow target, a gas substitution rate estimate, and a gas substitution rate target. The method further includes determining, based on the at least one base gas injector command, a gas injector command for at least one engine bank.