Engine Fuel Reformation Control Prevents Knocking
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Solution Overview
Problem
Internal combustion engines with fuel reformation cylinders face challenges in initiating fuel reforming reactions at low temperatures, leading to potential knocking and inefficient combustion due to the supply of non-reformed fuel at startup or in cold conditions.
Innovation Solution
A control device and method that inhibit fuel reforming operations in the fuel reformation cylinder when the gas temperature falls below a predetermined lower limit, ensuring only reformed fuel is supplied to the output cylinder, thereby preventing knocking and maintaining combustion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fuel reforming operation is executed at low gas temperature, then fuel reformation can be attempted, but non-reformed fuel is supplied to output cylinder causing knocking and inefficient combustion
Solution Approach 1:
The control device performs preliminary temperature assessment before initiating fuel reforming operation. It calculates the gas temperature at the compression top dead point based on intake air temperature, equivalence ratio, and compression ratio, and only permits reforming when the temperature is estimated to reach the lower limit value or higher, thereby preventing supply of non-reformed fuel to the output cylinder
Solution Approach 2:
The control device continuously monitors operating conditions (intake air temperature, equivalence ratio, compression ratio) and uses this feedback to dynamically determine whether fuel reforming should be executed. By comparing calculated gas temperature against the lower limit value, it provides real-time control feedback to prevent knocking and ensure combustion stability
2Reliability
If fuel reforming operation is inhibited at low gas temperature, then knocking is prevented, but fuel reformation capability is reduced
Solution Approach 1:
The control device dynamically adjusts fuel reforming operation based on real-time temperature conditions. When gas temperature is estimated to be below the lower limit value, it temporarily inhibits reforming operation to prevent knocking, but allows reforming when temperature conditions are favorable, thereby optimizing both reliability and productivity through adaptive control
3Productivity
If fuel is supplied to fuel reformation cylinder without temperature check, then reformation can proceed, but non-reformed fuel reaches output cylinder reducing anti-knock property
Solution Approach 1:
The control device performs preliminary calculation of gas temperature at compression top dead point before fuel injection into the reformation cylinder. It uses the relationship between intake air temperature, equivalence ratio, and compression ratio to predict whether the gas temperature will reach the lower limit value, and only permits fuel supply when reforming is guaranteed to occur
Solution Approach 2:
The control device acts as an intermediary between fuel supply and combustion. It introduces temperature prediction and control logic as an intermediate layer that assesses conditions before fuel reforming, preventing direct supply of non-reformed fuel to the output cylinder while maintaining efficient reformation when conditions are favorable
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 prevents the supply of non-reformed fuel, reducing knocking and ensuring efficient combustion by only initiating fuel reforming when the temperature meets the required threshold, thus enhancing engine performance and reducing emissions.
Implementation Method 1
an air-fuel mixture having a high equivalence ratio is adiabatically compressed within the fuel reformation cylinder. As a result, the fuel is reformed under a high temperature and high pressure environment
Implementation Method 2
the reformed fuel is combusted in the output cylinder to obtain an engine power
Data Source
AI summary
An internal combustion engine in which a fuel reforming operation in a fuel reformation cylinder is not executed when a gas temperature of a fuel reformation chamber at a time point when a piston in the fuel reformation cylinder reaches a compression top dead point is estimated to fall short of a reforming operation allowable lower limit gas temperature set based on a lower limit value of a reforming reaction enabling temperature. For example, fuel is supplied from an injector so that an equivalence ratio in the fuel reformation chamber is less than 1. Alternatively, the fuel supply from an injector is stopped. This way, a supply of non-reformed fuel from the fuel reformation cylinder to an output cylinder can be avoided, and knocking in the output cylinder can be avoided.