Vehicle AC Duct Humidity Control to Prevent Regeneration Droplets
Solution Overview
Problem
In vehicle air conditioning systems, water droplets tend to adhere and remain in the air conditioning duct during the regeneration process, leading to difficulties in discharging them to the vehicle exterior, which can result in water droplets entering the vehicle interior.
Innovation Solution
The system incorporates a first humidity control unit with a honeycomb structure and a PTC material, and a second humidity control unit with a moisture-absorbing material, both disposed in the air conditioning duct. The total amount of moisture-absorbing material in the second unit is controlled to be between 0.3 to 12 times that in the first unit, allowing for effective trapping and discharge of water vapor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the regeneration process is performed by heating the moisture absorbent device, then the adsorbed water vapor is released effectively, but water droplets form and adhere to the air conditioning duct interior
Solution Approach 1:
The moisture absorbent device is divided into multiple independent absorbent regions, each capable of being heated and regenerated separately. This segmentation allows controlled release of water vapor from different zones, preventing localized condensation and droplet formation in the duct.
Solution Approach 2:
A water vapor discharge control mechanism is introduced as an intermediary between the heating process and the air conditioning duct. This control mechanism regulates the discharge of water vapor, preventing excessive moisture release that would otherwise condense and form adhering droplets on the duct interior.
2Reliability
If ventilation is increased to control humidity in the vehicle interior, then humidity control is improved, but heater energy loss increases significantly
Solution Approach 1:
The moisture absorbent device performs preliminary moisture removal from the air before it enters the vehicle interior or before heating occurs. By pre-absorbing moisture, the system reduces the need for subsequent ventilation and heating to control humidity, thereby reducing heater energy loss while maintaining reliable humidity control.
Solution Approach 2:
The system periodically regenerates the moisture absorbent device by heating it to release adsorbed water vapor. This recovered water vapor is then controlled and discharged outside the vehicle, allowing the absorbent material to be reused. This cycle eliminates the need for continuous ventilation and heating, significantly reducing energy loss while maintaining humidity control reliability.
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 prevents water droplets from adhering to the air conditioning duct interior, improving humidity control performance and ensuring that water droplets are not reintroduced into the vehicle interior.
Implementation Method 1
at least the partition walls being made of a material having a PTC property
Implementation Method 2
it can easily heat the moisture absorbing material, while suppressing excessive heat generation and thermal deterioration of the moisture absorbing material
Implementation Method 3
a moisture absorbing material-containing layer formed on a surface of each of the partition walls
Data Source
AI summary
A vehicle air conditioning system includes: an air conditioning duct for allowing air to flow therethrough; a first humidity control unit having at least one humidity control device including a moisture absorbing material-containing layer, wherein the first humidity control unit is disposed in the air conditioning duct; a second humidity control unit having at least one humidity control member containing a moisture absorbing material, the second humidity control unit being disposed in the air conditioning duct on a downstream side of the first humidity control unit; and a power source for applying a voltage to the humidity control device. The total amount of the moisture absorbing material in the second humidity control unit is 0.3 to 12 times the total amount of the moisture absorbing material in the first humidity control unit.