Vehicle Air-Conditioning Blower Control During Engine Stop
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Solution Overview
Problem
During engine idling stop conditions in vehicles, the temperature of the heat exchanger drops, leading to insufficient heating and discomfort due to unsuitable air volume and temperature of the warm air blown into the vehicle compartment, especially when ambient air temperature is lower.
Innovation Solution
A vehicle air-conditioning apparatus with a blower fan, heat exchanger, temperature control unit, and temperature detection units that regulate air volume and temperature by switching between ambient and interior air flow paths to maintain comfortable heating conditions during engine idling stops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the engine stops without idling to save energy and reduce pollution, then energy consumption and environmental pollution are reduced, but the heat exchanger temperature drops and heating performance deteriorates
Solution Approach 1:
The system performs preliminary heating of air before the engine stops, storing thermal energy in the air and cabin space. When the engine stops and the heat exchanger temperature drops, the pre-heated air continues to provide thermal comfort, anticipating the temperature drop and preparing compensatory measures in advance.
Solution Approach 2:
The system changes operational parameters by switching between different air sources (ambient air, cabin air, recirculated air) and adjusting blower fan speed based on detected temperature conditions. When the heat exchanger temperature drops below a threshold, the system transitions to using warmer cabin air or reduces air volume to maintain comfort despite reduced heating capacity.
2Productivity
If constant air volume is ventilated during engine stop, then air circulation is maintained, but the warm air temperature is insufficient and passenger comfort deteriorates
Solution Approach 1:
The system dynamically adjusts the air volume based on real-time temperature detection. The blower fan speed is varied according to the heat exchanger temperature and cabin temperature conditions, transitioning from constant high air volume to variable air volume that matches the available thermal energy, ensuring comfort is maintained throughout the engine stop period.
Solution Approach 2:
The temperature detection unit continuously monitors the heat exchanger temperature and provides feedback to the control unit. Based on this feedback, the system adjusts the air volume and air source selection to maintain passenger comfort, creating a closed-loop control system that responds to actual thermal conditions rather than operating on fixed parameters.
3Temperature
If warm air is blown strongly to maintain heating, then temperature comfort is improved, but the air volume becomes excessive and causes cool sensation on passenger skin
Solution Approach 1:
The system simultaneously adjusts both temperature and air volume parameters based on detected conditions. When the heat exchanger temperature drops, the system not only reduces air volume but may also switch to warmer cabin air sources, coordinating changes in multiple parameters to maintain comfort without creating the cool skin sensation caused by high-velocity warm air.
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 system ensures continued heating with an appropriate air volume, reducing passenger discomfort and energy consumption by adjusting air volume based on detected temperatures, even when the engine is temporarily stopped during no idling operations.
Implementation Method 1
a heat exchanger for heating the air-conditioning air by heat exchanging with cooling water for the engine
Data Source
AI summary
A vehicle air-conditioning apparatus 10, installed in a vehicle having a no idling system (in which the engine stops rather than idling). The apparatus includes a blower fan 12 for sending air-conditioning air for temperature control in a vehicle compartment R to the vehicle compartment; a heater core 14 for heating the air-conditioning air by heat exchange with cooling water of an engine; and an automatic air controller 18 for executing temperature regulation control in the vehicle compartment by regulating an air-conditioning air volume to be heat exchanged with the heater core. The automatic air controller controls, on heating, during a no idling operation, driving of a blower fan so as to supply a determined air volume in response to the ambient air temperature detected by an ambient air temperature sensor 22a.