Parallel Liquid Heater Modules for Low-Pressure Vehicle Cabin Heating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric heating devices for motor vehicles are too large, heavy, and have significant pressure drop and heating inertia, making them unsuitable for rapid and effective heating of the passenger compartment, especially in cold environments.
Innovation Solution
The design includes two heating modules arranged in a parallel configuration with a communication channel between them, forming a 'U' shaped path, and featuring an internal cavity for expansion control, which reduces size and pressure drop while minimizing heating inertia.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional electric heating devices with PTC elements in a casing are used, then heating function is provided, but the device size becomes large and weight increases
Solution Approach 1:
The heating device is divided into multiple heating modules (first heating module, second heating module) that can be arranged in series or parallel configurations. Each module contains heating elements and liquid guiding circuits, allowing the system to achieve the required heating function while distributing the mass and reducing the weight of any single component.
Solution Approach 2:
The heating device is designed to work with both internal combustion engine vehicles (using coolant) and electric vehicles (using water heating circuit), serving multiple vehicle types and heating applications (passenger compartment heating, defrosting, demisting) through a unified design that accepts different heat transfer liquids.
2Reliability
If traditional electric heating devices with PTC elements are used, then heating function is provided, but the pressure drop becomes high
Solution Approach 1:
The device incorporates expansion control means with calibrated passages that can slide along the internal cavity of the core, dynamically adjusting the liquid flow path and pressure characteristics based on thermal expansion conditions, thereby optimizing pressure drop characteristics while maintaining heating performance.
Solution Approach 2:
A communication channel is introduced as an intermediary element between the first and second heating modules, allowing liquid to flow between the series guide circuits and reducing pressure accumulation by providing an alternative flow path that balances the pressure distribution across the heating modules.
3Reliability
If traditional electric heating devices are used, then heating function is provided, but the heating inertia becomes significant
Solution Approach 1:
By segmenting the heating system into multiple independent heating modules with separate liquid guiding circuits, the thermal mass is distributed across smaller units that can heat up and respond more quickly to control signals, reducing the overall heating inertia compared to a single large heating element.
Solution Approach 2:
The heating modules are arranged in a compact three-dimensional configuration with inlet and outlet pipes positioned on the same side, creating a U-shaped or parallel flow path that reduces the length of the liquid circulation loop and minimizes thermal inertia by shortening the distance heat must travel through the liquid.
4Volume of moving object
If heating modules are arranged in series to form U-shaped path, then compact design is achieved, but pressure drop may increase
Solution Approach 1:
The communication channel acts as a pressure-balancing intermediary between series-connected heating modules, providing a direct liquid communication path that equalizes pressure differences created by the U-shaped configuration and prevents excessive pressure drop despite the compact arrangement.
5Volume of moving object
If expansion tank is integrated into the heating device, then system compactness is improved, but device complexity increases
Solution Approach 1:
The expansion tank function is merged with the existing heating module structure by utilizing the internal cavity of the core as the expansion space. The core's internal cavity communicates with the liquid guiding circuit and contains air that is compressed under liquid expansion, eliminating the need for a separate expansion tank component.
Solution Approach 2:
The core structure serves multiple functions simultaneously: it acts as the central structural element, the housing for heating elements, the expansion tank through its internal cavity, and part of the liquid guiding circuit. This multi-functionality reduces the number of separate components and simplifies the overall device design.
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 results in a compact, efficient heating device with reduced pressure drop and lower heating inertia, meeting the constraints imposed by car manufacturers and enabling rapid heating of the passenger compartment.
Implementation Method 1
heating elements, such as elements with a positive temperature coefficient or PTC
Implementation Method 2
enclosure 13...heating elements...to heat the liquid by heat exchange
Implementation Method 3
core of at least one heating module comprises an internal cavity communicating with said liquid guiding circuit, and comprising air capable of being compressed under the effect of the expansion of the heated liquid
Implementation Method 4
under the effect of the expansion of the heated liquid
Implementation Method 5
heating means 13 surrounding said core so as to define a circuit 15 for guiding the liquid to be heated around said core...to heat the liquid by heat exchange between the enclosure and the liquid
Data Source
Figure 1~2b
Figure 3a~4
Figure 5a~5b
AI summary
The invention relates to an electrical liquid heating device for a motor vehicle. The heating device comprises at least a first (7a) and a second (7b) heating module for heating the aforementioned liquid, defining at least one circuit (15) for guiding the liquid to be heated. The device is characterised in that the heating modules (7a, 7b) each have a generally cylindrical shape and are arranged side by side substantially in parallel. The invention also relates to a heating and/or air-conditioning unit for a motor vehicle, comprising such a heating device (5).