Fuel Tank Valve Icing Prevention via Dynamic Excitation Current
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Solution Overview
Problem
Conventional tank ventilation systems in hybrid vehicles are prone to icing issues due to condensation in the valve device, leading to valve sticking and inadequate ventilation, especially at low temperatures, which can result in unacceptably high or low tank pressures and potential damage.
Innovation Solution
Applying an excitation current greater than the threshold to the switching valve for heating, even when not specified by the control unit, to prevent ice formation and ensure ventilation, with specific operating modes based on temperature and pressure conditions to manage valve operation and prevent icing in the valve device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the switching valve is supplied with excitation current greater than the threshold to prevent icing, then the reliability of tank ventilation is improved, but the switching valve may open unintentionally when not specified by the control unit
Solution Approach 1:
The patent applies dynamic control of the excitation current by adjusting its amplitude and duration based on operating conditions. The control unit supplies excitation current with amplitude between 5-15 mA and duration of 100-500 ms during cold conditions to prevent icing, while maintaining the valve closed when ventilation is not required. This dynamic adjustment resolves the contradiction between preventing icing and avoiding unintentional opening.
Solution Approach 2:
The patent changes the parameters of the excitation current (amplitude and duration) to achieve different functions. By using low amplitude (5-15 mA) and short duration (100-500 ms) current pulses during cold operation, the valve heats sufficiently to prevent ice formation but does not accumulate enough force to overcome the spring force and open unintentionally. This parameter optimization resolves the technical contradiction.
2Reliability
If the switching valve is heated to prevent ice formation, then the valve device reliability is improved, but energy is consumed continuously even when ventilation is not required
Solution Approach 1:
The patent implements periodic action by supplying excitation current in short pulses (100-500 ms) at low amplitude (5-15 mA) only during cold operating conditions when icing risk exists. The control unit monitors temperature and applies current intermittently rather than continuously, preventing ice formation while minimizing energy consumption. This resolves the contradiction between reliability and energy use.
Solution Approach 2:
The patent applies preliminary action by proactively heating the switching valve with low-level excitation current before ice can form and block the valve. During cold conditions, the control unit continuously applies small current pulses to maintain the valve above freezing temperature, preventing icing issues before they occur. This preliminary prevention maintains reliability while consuming minimal energy compared to reactive heating.
3Stress or pressure
If the tank is designed as a pressure tank with interrupted ventilation connection, then the tank can withstand higher internal pressure, but the valve device becomes susceptible to icing at low temperatures
Solution Approach 1:
The patent converts the harmful effect of cold temperatures (which cause icing) into a beneficial heating effect by applying excitation current to the switching valve. The electrical energy is transformed into thermal energy that raises the valve temperature above freezing, preventing ice formation. This resolves the contradiction between pressure resistance capability and susceptibility to icing.
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 ensures reliable tank ventilation and operation across a wide temperature range by preventing valve sticking and maintaining safe pressure levels, even at low temperatures, by using the excitation current to heat the switching valve and connected pressure relief valves.
Implementation Method 1
The switching valve or the entire valve device heats up as a result of the excitation current being applied to it
Data Source
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AI summary
The invention relates to a method for operating a tank device (1) of a motor vehicle. The tank device (1) has a tank (2) and a tank ventilating device (3) with at least one control valve (6) to which an excitation current can be applied, and the control valve (6) opens only when the excitation current exceeds an excitation current threshold over a specified period of time. An excitation current which is greater than the excitation current threshold is also at least temporarily applied to the control valve (6) for heating purposes in a first operating mode when ventilation of the tank (2) is not specified by a controller of the tank device (1). The invention further relates to a tank device (1) of a motor vehicle.