Fuel Cell Stack Heating Control for Cold Starts After Short Stops
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Solution Overview
Problem
In fuel cell vehicles, the target heating value of the fuel cell stack is often derived based solely on the coolant temperature, leading to excessive heat emission and potential damage to the fuel cell stack, especially during cold starts after short stop intervals.
Innovation Solution
A cold start control method that calculates a target heating value for the fuel cell stack by determining the required time from coolant temperature measurement to cold start mode entry, and correcting this value based on the ratio of estimated time to required time, ensuring the fuel cell stack reaches an optimized heating value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the target heating value of the fuel cell stack is derived based solely on the coolant temperature during cold start, then the heating control is simplified, but excessive heat emission occurs leading to durability degradation of the fuel cell stack
Solution Approach 1:
The patent segments the heating control process into multiple stages: initial heating phase and main heating phase. The controller determines whether to enter cold start mode based on temperature difference between coolant and stack, applies initial heating value first, then switches to main heating value. This segmentation prevents excessive heat emission while maintaining simplicity.
Solution Approach 2:
The patent implements dynamic adjustment of heating value based on real-time temperature monitoring. The controller continuously monitors stack temperature and coolant temperature, dynamically switching between initial heating value and main heating value based on whether the temperature difference threshold is exceeded. This dynamic control optimizes heating efficiency while preventing durability degradation.
2Device complexity
If the target heating value is derived based solely on coolant temperature, then the control process is simple, but fuel consumption increases due to excessive fuel use for heat emission
Solution Approach 1:
The heating process is divided into initial heating phase and main heating phase with different heating values. The controller applies initial heating value first, then switches to main heating value when temperature difference exceeds threshold. This segmentation reduces unnecessary fuel consumption while keeping control logic simple.
Solution Approach 2:
The controller continuously monitors stack temperature and coolant temperature, using this feedback to dynamically adjust heating value. When temperature difference exceeds threshold, it switches from initial to main heating value. This feedback mechanism optimizes fuel consumption while maintaining simple control structure.
3Speed
If the target heating value is derived based solely on coolant temperature during cold start, then the heating response is fast, but the actual heating requirement is not met accurately causing overheating
Solution Approach 1:
The patent segments heating control into two phases: initial heating with initial heating value for fast response, and main heating with main heating value for accurate temperature control. This segmentation maintains fast heating response while improving temperature control accuracy.
Solution Approach 2:
The controller dynamically switches between initial heating value and main heating value based on real-time temperature monitoring. This dynamic adjustment ensures fast initial heating response while achieving accurate temperature control throughout the cold start process.
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 method optimizes the target heating value to prevent unnecessary heat emission and durability degradation of the fuel cell stack, while also reducing fuel consumption by minimizing excessive fuel use for heat emission.
Implementation Method 1
a fuel cell stack that converts heat energy into electricity energy using a chemical reaction of oxygen and hydrogen. In an anode (or an oxidation electrode), hydrogen that is a fuel is oxidized, and thus hydrogen ions and electrons are generated
Implementation Method 2
In an anode (or an oxidation electrode), hydrogen that is a fuel is oxidized, and thus hydrogen ions and electrons are generated
Data Source
AI summary
A cold start control method and system for fuel cell vehicles determines when the fuel cell vehicle is started, whether the fuel cell vehicle enters a cold start mode. An estimated time estimated to be required until the stopped vehicle coolant temperature, which is measured in a state in which the fuel cell vehicle is stopped before being started, reaches a reference temperature is derived. The required time required from a point in time at which the stopped vehicle coolant temperature is measured to a point in time at which the fuel cell vehicle enters the cold start mode is derived. A target heating value is corrected according to a ration between the estimated time and the required time to derive a final target heating value. The heating value of the fuel cell stack is caused to reach the final target heating value.