In-Vehicle Air Conditioner Blower Control for Evaporator Odor Suppression
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Solution Overview
Problem
In electrically powered vehicles, pre-air-conditioning using external power supply can lead to condensate evaporation on the evaporator surface during battery charging, causing foul odors and discomfort when occupants enter the vehicle.
Innovation Solution
A controller-operated blower system that performs simplified pre-air-conditioning by increasing blower output during battery charging to prevent condensate evaporation and discharge it through outlets, while minimizing power consumption and odor release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the cooling device operates to cool the vehicle compartment, then the temperature is reduced, but condensate evaporates causing foul odors
Solution Approach 1:
The system performs preliminary action by operating the blower at high output before the cooling device starts, to prevent condensate from adhering to the evaporator surface in the first place. This proactive measure eliminates the root cause of odor generation rather than addressing it after the fact.
Solution Approach 2:
The system converts the harmful effect of condensate accumulation into a beneficial outcome by using the blower's air flow to actively remove condensate through the drainage path. The same air flow that could potentially cause odor by evaporating condensate is instead used to prevent adhesion and facilitate drainage.
2Object-generated harmful factors
If the blower output is increased during simplified pre-air-conditioning, then condensate evaporation is suppressed, but power consumption increases
Solution Approach 1:
The system applies partial action by operating the blower at high output only for a limited predetermined period immediately after the cooling device stops, rather than continuously. This excessive action during the critical period is sufficient to prevent condensate adhesion and evaporation, while avoiding unnecessary energy consumption during later periods when the risk is lower.
3Use of energy by moving object
If the cooling device is stopped during battery charging, then power consumption is reduced, but condensate evaporates causing discomfort
Solution Approach 1:
The system performs preliminary action by operating the blower at high output before the cooling device stops and for a predetermined period after stopping. This proactive blower operation prevents condensate from adhering to the evaporator surface during the transition period when the cooling device is stopped, eliminating the source of foul odors without requiring continuous cooling operation.
Solution Approach 2:
The system extracts the odor-causing condensate from the evaporator surface by using the blower's air flow to carry it through the drainage path and discharge it outside the vehicle. This separation removes the harmful substance (condensate) from the interior environment where it could evaporate and cause odor.
4Loss of time
If simplified pre-air-conditioning is performed with the cooling device stopped, then battery charging time is reduced, but condensate evaporates causing foul smells
Solution Approach 1:
The system performs preliminary action by operating the blower at high output during the predetermined period after the cooling device stops. This proactive measure prevents condensate from adhering to the evaporator surface during the simplified pre-air-conditioning period, eliminating the source of foul smells while allowing the cooling device to remain stopped and charging to proceed efficiently.
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
Suppresses odor generation and discomfort by reducing condensate on the evaporator surface, extending battery charging time, and enhancing vehicle travel distance by minimizing air conditioner power consumption.
Implementation Method 1
when condensate adheres to the evaporator surface due to condensation caused by the operation of the cooling device while the vehicle is traveling, the condensate would evaporate due to blown air
Implementation Method 2
The evaporator as a heat exchanger cools the blown air that passes through the evaporator by vaporizing the compressed and liquefied refrigerant. At this time, the evaporator cools the air that passes through it, causing the moisture in the air to condense
Implementation Method 3
the evaporator as a heat exchanger cools the blown air that passes through the evaporator by vaporizing the compressed and liquefied refrigerant
Data Source
AI summary
An in-vehicle air conditioner includes a blower configured to send blown air to a vehicle compartment, a cooling device having a heat exchanger for cooling the blown air, and a controller configured to control the blower and the cooling device. The controller operates the blower to perform a simplified pre-air-conditioning for introducing outside air into the vehicle compartment while the cooling device is stopped, in a case where an in-vehicle battery is being charged by an external power supply and no occupant is present in the vehicle compartment. In the simplified pre-air-conditioning, the controller increases output of the blower during a predetermined period of time in a case where the cooling device has been operating immediately before an ignition switch is turned off, so as to be greater as compared to a case where the cooling device has not being operating immediately before the ignition switch is turned off.