PTC Heater Delivery Module for Tank Additive Heating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conveyor modules for tanks storing liquid additives like urea-water solutions face challenges in providing efficient and uniform heating without excessive power loss, especially at low temperatures, and must prevent chemical conversion of the additive into ammonia, which can damage components.
Innovation Solution
A method for producing a conveyor module with an electric PTC heater involves specifying maximum electrical power, determining thermal conductivity, calculating the switching temperature, and assembling a PTC material with a corresponding switching temperature to achieve efficient and uniform heating while preventing excessive temperature rise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If electric heaters are used to heat the liquid additive quickly after vehicle start, then heating speed is improved, but power consumption exceeds available electrical energy from the energy store
Solution Approach 1:
The patent changes the key parameter of the heating element from a conventional resistive heater to a PTC (positive temperature coefficient) heater. This material property change causes the electrical resistance to increase automatically with temperature, creating a self-regulating heating effect that reduces power consumption at higher temperatures while maintaining rapid heating capability at lower temperatures.
Solution Approach 2:
The PTC heater performs self-regulation of its heating output based on its own temperature. As the heater warms the liquid additive, the PTC material's resistance increases automatically, reducing the current draw and power consumption without external control. This self-service mechanism ensures the heating system adapts to available electrical energy limits.
2Power
If higher electrical power is provided to the heater, then heating output is improved, but temperature control precision deteriorates due to risk of exceeding maximum temperature
Solution Approach 1:
The patent utilizes the temperature-dependent electrical resistance parameter of PTC materials to achieve automatic power regulation. As temperature approaches the switching point, resistance increases sharply, naturally limiting power input and preventing overheating. This intrinsic parameter change provides both high heating power when needed and precise temperature control near the maximum.
Solution Approach 2:
The PTC heater incorporates inherent feedback through its material properties. The temperature rise caused by heating directly increases electrical resistance, which reduces current flow and power input. This negative feedback loop automatically prevents temperature runaway and ensures precise temperature control without external sensors or control systems.
3Stability of the object's composition
If uniform heating throughout the tank is achieved, then heating effectiveness is improved, but power loss increases due to heat distribution requirements
Solution Approach 1:
The patent applies heating locally at the bottom of the tank where the liquid additive is stored, rather than distributing heating elements throughout the entire tank volume. The PTC heater's self-regulating nature ensures efficient local heating that naturally conveys warmth throughout the liquid without requiring additional power for heat distribution systems.
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 solution enables the conveyor module to operate with minimal power loss and maintain a consistent heating output, preventing chemical conversion of the liquid additive, ensuring reliable operation across varying temperatures.
Implementation Method 1
Electric PTC heating elements (PTC=positive temperature coefficient), for example, are known. These are electrical heating elements whose electrical resistance is particularly dependent on temperature.
Implementation Method 2
With different PTC heating elements there is a characteristic and/or material-specific switching temperature at which the electrical resistance suddenly increases. Therefore, the heating current through a PTC heating element reduces when the switching temperature is reached
Data Source
AI summary
The invention relates to a method for producing a delivery module (2) having an electrical PTC heater (1) for installation into a tank (3) for storing a liquid additive. In a method step a), a maximum electrical power is defined, said electrical power being made available to the delivery module (2). In a method step b), a thermal conductivity of the delivery module (2) is established from a location (21) of the electrical PTC heater (1) in the tank (3). In step c), a switching temperature (4) of the PTC heater (1) is calculated from the maximum electrical power and the thermal conductivity. In step d), a PTC material with a corresponding switching temperature (4) for the PTC heater (1) is fitted at the location (21).