Diesel Exhaust Fluid Heating Control Using Dual Temperature Sensors
Solution Overview
Problem
Conventional diesel exhaust fluid (DEF) temperature control systems rely on ambient air temperature sensors, which can be inaccurate due to sensor tolerances and mounting locations, leading to potential refreezing or overheating of DEF, affecting the efficiency and reliability of SCR systems in diesel engines.
Innovation Solution
A system and method that utilize both ambient air temperature and DEF storage tank temperature sensors to generate heating commands, allowing the DEF heating control module to adjust heating based on the difference between these temperatures, ensuring accurate temperature management and preventing DEF from freezing or overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If ambient air temperature sensor is used for DEF heating control, then the system structure is simple, but the temperature control accuracy deteriorates due to sensor tolerances and mounting location variations
Solution Approach 1:
The patent introduces an intermediary correction mechanism that uses the DEF tank temperature sensor as a reference to calibrate and correct the ambient air temperature sensor readings. This intermediary approach allows the system to maintain the simplicity of using ambient temperature sensing while compensating for its inaccuracies through a secondary reference measurement.
Solution Approach 2:
The system implements feedback by continuously monitoring the DEF tank temperature and using it to validate and adjust the ambient air temperature sensor readings. When the DEF tank temperature deviates from expected values based on ambient temperature, the system feeds back correction factors to improve the accuracy of temperature-based heating control decisions.
2Ease of operation
If ambient air temperature sensor is used for DEF heating control, then the installation is easy, but the reliability deteriorates due to sensor defects and inaccuracy over time
Solution Approach 1:
The patent applies beforehand cushioning by implementing a redundant DEF tank temperature sensor as a backup and validation mechanism. This prior cushioning measure ensures that if the ambient air temperature sensor becomes defective or inaccurate over time, the system can rely on the DEF tank temperature sensor to maintain reliable heating control, preventing system failure before it occurs.
3Device complexity
If single temperature sensor is used, then the device complexity is low, but the temperature management accuracy deteriorates
Solution Approach 1:
The patent merges the functionality of multiple temperature sensors (ambient air temperature sensor and DEF tank temperature sensor) into a unified temperature management system. By combining the readings from both sensors and using them together for heating control decisions, the system achieves higher temperature management accuracy than would be possible with a single sensor, while minimizing overall system complexity.
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 enhances the accuracy of DEF temperature control, reducing the risk of freezing or overheating, thereby improving the reliability and efficiency of SCR systems in varying ambient conditions.
Implementation Method 1
Emissions regulations require SCR systems to provide a temperature control system for heating the DEF when operating at low ambient temperatures
Implementation Method 2
A system and method that utilize both ambient air temperature and DEF storage tank temperature sensors to generate heating commands
Data Source
AI summary
According to one embodiment, an apparatus for controlling the heating of diesel exhaust fluid (DEF) in a DEF delivery system includes a temperature comparison module that compares a difference between a sensed ambient air temperature and a sensed DEF tank temperature with a predetermined temperature difference threshold. Additionally, the apparatus includes a DEF heating status module that is configured to generate a DEF heating command according to (i) the sensed ambient air temperature if the difference between the sensed ambient air temperature and sensed DEF tank temperature is less than the predetermined temperature threshold; and (ii) the sensed DEF tank temperature if the difference between the sensed ambient air temperature and sensed DEF tank temperature is more than the predetermined temperature threshold. The apparatus also includes a DEF heating control module that is configured to control the heating of the DEF according to the DEF heating command.