Glowplug Temperature Estimation via Nonlinear Differential Equation
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Solution Overview
Problem
Existing glowplug systems in compression-ignition engines lack an efficient method for accurately predicting and controlling glowplug temperature, which affects combustion efficiency and engine performance, especially in cold conditions.
Innovation Solution
A method and device for predicting glowplug temperature using a nonlinear differential equation that models radiative heat transfer, incorporating input values such as engine load, speed, and combustion chamber temperature to control the power supply through pulse width modulation, allowing for precise control of MOSFETs or relays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If glowplug temperature is controlled using conventional methods, then the system is simple to implement, but the temperature control accuracy is insufficient affecting combustion efficiency
Solution Approach 1:
The patent implements a feedback mechanism by continuously monitoring glowplug temperature through resistance measurements and comparing it with target temperature values. The control unit adjusts the power supply based on the temperature difference, creating a closed-loop control system that improves temperature control accuracy while maintaining reasonable system complexity
Solution Approach 2:
The patent replaces direct temperature sensing with electrical resistance measurement to infer temperature. Instead of using complex thermal sensors, the system utilizes the inherent electrical properties of the glowplug material, substituting a simple electrical measurement system for what would otherwise require complex thermal sensing and measurement infrastructure
2Productivity
If glowplug temperature is increased to improve combustion efficiency, then combustion performance improves, but energy consumption increases
Solution Approach 1:
The patent implements dynamic control of glowplug temperature by continuously adjusting power supply based on real-time temperature measurements and engine operating conditions. Rather than maintaining a constant high temperature, the system dynamically optimizes temperature levels to achieve sufficient combustion efficiency while minimizing energy consumption at different operating points
Solution Approach 2:
The patent changes the operating parameters of the glowplug by adjusting power supply voltage and duty cycle based on measured temperature and engine conditions. The system modifies electrical parameters (voltage, current, pulse width) to optimize the balance between combustion efficiency and energy consumption, allowing the glowplug to operate at different temperature regimes depending on requirements
3Reliability
If glowplug operates at high temperature continuously, then combustion aid is effective, but glowplug lifespan decreases
Solution Approach 1:
The patent employs periodic or pulsed operation of the glowplug rather than continuous operation at high temperature. By controlling the duty cycle of power supply and operating the glowplug in intermittent cycles, the system maintains effective combustion aid during required periods while allowing cooling intervals that extend the overall lifespan of the glowplug
Solution Approach 2:
The patent implements protective control strategies that anticipate thermal stress on the glowplug. By monitoring temperature and engine operating conditions, the system preemptively reduces power supply when thermal stress becomes excessive, cushioning against conditions that would otherwise accelerate degradation and extend component life
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 enables accurate temperature control of glowplugs, improving combustion efficiency, reducing fuel consumption, and extending glowplug lifespan by predicting and adjusting the power supply based on real-time engine conditions without the need for separate temperature sensors.
Implementation Method 1
The glowplug whose tip can rise up to high temperatures of above 900° C. by means of an electrical to thermal power conversion. Glowplugs function as electrical resistors.
Implementation Method 2
A differential equation is disclosed which comprises a fourth power of the glowplug temperature for modelling a radiative heat transfer.
Data Source
AI summary
A method is provided for controlling one or more glowplugs in a compression-ignition engine. The controlling of the glowplug involves the prediction of a glow plug temperature to control a power supply to the glowplug. A supplied power to a glowplug and a combustion chamber temperature is determined. A temperature of the glowplug is predicted and the predicted glowplug temperature is used to control a power supply to the glowplug. The predicted glowplug temperature is derived from a numerical solution of a differential equation for the glowplug temperature. The differential equation is nonlinear in the glowplug temperature.