LNG Tank Level Calibration Using Pressure Sensor Data
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Solution Overview
Problem
Current fuel storage tank systems for internal combustion engines, particularly in mobile machinery, face inaccuracies in correlating tank level and pressure due to various factors, leading to residual liquefied natural gas (LNG) not being usable due to low pressure, and existing systems do not accurately indicate the tank as empty when residual LNG is present.
Innovation Solution
A gaseous fuel supply system that includes a storage tank with a liquid level sensor and pressure sensor, monitored by a controller that determines a calibrated level range based on stored values, accurately indicating when the tank is empty or full, ensuring accurate fuel level indication even when pressure is too low to supply usable LNG.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a liquid level sensor is used to measure tank level, then the tank level indicator displays the perceived usable tank level, but the indicator shows residual LNG as usable fuel when pressure is too low to supply the engine
Solution Approach 1:
The patent combines the liquid level sensor data with pressure sensor data to create a unified fuel status indication system. The controller integrates both measurements to determine whether fuel is actually usable, merging two separate measurement functions into a single reliable indication that accounts for both level and pressure conditions.
Solution Approach 2:
The controller acts as an intermediary that processes both level sensor and pressure sensor signals before presenting the final fuel status to the operator. It mediates between the raw sensor data and the displayed indication, applying logic to determine if the fuel is truly usable based on both level and pressure thresholds.
2Quantity of substance
If the tank level indicator shows residual LNG as available fuel, then the operator sees a higher fuel level, but the engine cannot utilize the residual LNG due to insufficient pressure
Solution Approach 1:
The system implements feedback by continuously monitoring both level and pressure conditions and adjusting the fuel status indication accordingly. When pressure drops below the threshold required for engine operation, the system provides feedback to the operator that the fuel is no longer usable, even if liquid remains in the tank, preventing misleading information about available fuel quantity.
3Adaptability or versatility
If capacitance of the liquid level sensor changes over time or different fuel types are used, then sensor accuracy varies, but no compensation mechanism is provided
Solution Approach 1:
The patent addresses sensor accuracy variations by monitoring pressure as an additional parameter. When fuel type changes or sensor characteristics drift over time, the pressure measurement provides a reference that helps maintain accurate fuel status indication. The system adapts to different fuel types and sensor conditions by using the relationship between pressure and level measurements.
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
The system provides a more accurate measurement of usable LNG, preventing the engine from running out of fuel and allowing operators to determine remaining fuel levels accurately, accounting for factors affecting sensor accuracy such as capacitance changes and different fuel types.
Implementation Method 1
the level of LNG stored in the storage tank may be measured by a liquid level sensor, such as a capacitance level sensor
Implementation Method 2
A pressure sensor for measuring a pressure value of gaseous fuel in the fuel supply system
Data Source
AI summary
A gaseous fuel supply system for an internal combustion engine may include a storage tank for storing liquefied gaseous fuel and supplying the fuel to the engine. The system may also include a liquid level sensor for measuring a level value of the liquefied gaseous fuel in the storage tank and a pressure sensor for measuring a pressure value of gaseous fuel in the fuel supply system. The system may further include a controller. The controller may be configured to: monitor a pressure signal of the pressure sensor indicating the pressure value and a tank level signal of the liquid level sensor indicating the level value; store the level value when the pressure value indicates the storage tank is empty; store the level value when the pressure value or the level value indicates the storage tank is full; and determine a calibrated level range based on the stored level values.