Vehicle Air Conditioning Partition Wall Pressure Equalization
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Solution Overview
Problem
Modern multi-zone motor vehicle air conditioning systems face challenges in minimizing rear air reheating, particularly in three- or four-zone systems, due to uneven air flow distribution and pressure differences across the radiator gills, leading to increased residual heating and undesirable acoustic effects.
Innovation Solution
A motor vehicle air conditioning system with a partition wall featuring a pressure equalization opening and a separating element, such as a resin-coated strip, to minimize pressure differences between climate zones, allowing direct airflow from the mixing chamber to the rear area without passing through the heating device, thus reducing residual heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a high blower level is set in the rear area, then the cooling performance in the rear area is improved, but the air flow control greatly throttles the outlet flaps of the front zones, causing the rear area exhaust temperatures to increase by 7 to 11 K
Solution Approach 1:
The heating device is divided into multiple sections corresponding to different climate zones, with separate air flow paths for front and rear areas. This allows independent control of air flow to each zone, preventing the throttling effect that causes rear area reheating while maintaining cooling performance.
Solution Approach 2:
A partition wall with a pressure equalization opening is introduced as an intermediary element between the front and rear climate zones. This opening allows pressure equalization to prevent unwanted air flow through the radiator gills, thereby reducing rear area exhaust temperature increase without compromising cooling effectiveness.
2Ease of operation
If the outlet flaps of the front zones are throttled to control air flow, then the air flow distribution is improved, but the rear area exhaust temperatures increase due to air-side flow path across the radiator gills
Solution Approach 1:
The heating device is segmented into multiple sections with dedicated air flow paths for different zones. This eliminates the need to throttle front zone outlet flaps to control rear area air flow, as each zone has its own controlled path, preventing the temperature increase caused by air-side flow across radiator gills.
Solution Approach 2:
The partition wall with pressure equalization opening acts as an intermediary that balances pressure between zones, preventing the pressure-driven air flow through radiator gills that causes rear area reheating, while allowing independent air flow control for each zone.
3Device complexity
If non-actuator operated flaps are used to control air flow, then the device complexity is reduced, but the flaps release the air flow path too quickly when pressure difference falls, causing inrush of cold air and increased acoustic effects
Solution Approach 1:
The partition wall with pressure equalization opening serves as an intermediary that gradually balances pressure between zones, preventing the sudden release of air flow that causes cold air inrush and acoustic effects, while maintaining a simple flap mechanism without actuators.
Solution Approach 2:
The pressure equalization opening provides a gradual pressure balancing effect before the flaps fully open, cushioning the transition and preventing sudden air flow changes that would cause acoustic effects and cold air inrush, while keeping the mechanism simple and actuator-free.
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 configuration effectively reduces rear air reheating by minimizing the pressure difference across the radiator gills, maintaining comfort and improving acoustic behavior while being cost-effective by eliminating the need for additional flaps or bypass ducts, achieving a temperature increase of less than 5K in the rear area.
Implementation Method 1
at least one partition has a pressure equalization opening which provides a partial flow path for a partial air flow of the main air flow. A pressure difference between the climate zones is eliminated or minimized
Implementation Method 2
The regulated state of a motor vehicle air conditioning system without secondary measures, this leads to the rear area exhaust temperatures increasing by 7 to 11 K. This increased residual heating is due to the air-side flow path across the radiator gills provided in the corrugated fins of a heating device with simultaneous heating of the air
Data Source
Figure 1a~1b
Figure 2
Figure 3
AI summary
The system (1) has multiple climate zones (14, 15) including a heating device (4) that is arranged in a melt flow path of an air flow of air circulating in the system, and a separating wall (6) that separates the climate zones from each other. The separating wall has a pressure compensation opening (18) that provides a partial flow path for a partial air flow of a main air flow. The heating device has a separating element (19) i.e. stripe shaped element, that corresponds to an area of the climate zones. The separating wall is arranged perpendicular to the heating device. The separating element is manufactured from a Moltopren(RTM: flexible polyurethane foam).