Vehicle HVAC Fan Control for Engine-Load Noise Reduction
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Solution Overview
Problem
Vehicle HVAC systems generate significant external noise, particularly when stationary and idling, due to fan operation, which is not effectively mitigated by existing technologies.
Innovation Solution
A vehicle HVAC system with a refrigeration circuit and a controller that adjusts operation based on vehicle conditions such as door position, location, and propulsion system load, switching to a quieter mode by reducing the speed of refrigeration components when appropriate conditions are met.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the fan speed is increased to improve cooling efficiency, then the temperature control performance is improved, but the external noise generated by the fan increases
Solution Approach 1:
The patent applies dynamics by making the fan speed variable rather than fixed. The controller dynamically adjusts fan speed based on real-time detection of vehicle conditions (door position, location, propulsion load). When the vehicle is stationary with doors closed and low propulsion load, the fan operates at reduced speed to minimize noise. When cooling demand increases (doors open, high load), fan speed increases to maintain temperature control performance.
Solution Approach 2:
The patent changes the operating parameters of the fan based on vehicle conditions. The controller modifies fan speed as a variable parameter rather than maintaining constant operation. This parameter change allows the system to optimize between noise reduction (lower speed) and cooling efficiency (higher speed) based on actual vehicle state, resolving the contradiction between temperature control and noise generation.
2Temperature
If the refrigeration circuit operates at full capacity to maintain temperature control, then the temperature regulation is improved, but the noise from HVAC components increases
Solution Approach 1:
The refrigeration circuit operates dynamically with variable capacity rather than fixed full-capacity operation. The controller adjusts compressor speed and fan speeds based on detected vehicle conditions. When the vehicle is stationary with favorable conditions (doors closed, low propulsion load), the refrigeration circuit operates at reduced capacity to minimize noise from compressors and fans while maintaining adequate temperature control through strategic placement of heat exchangers.
3Ease of operation
If the vehicle is stationary with engine idling, then passenger comfort is prioritized, but the HVAC system generates maximum external noise
Solution Approach 1:
The patent implements feedback control where the controller continuously detects vehicle conditions (door position, location via GPS, propulsion system load) and adjusts refrigeration circuit operation accordingly. When the vehicle is stationary with doors closed and low propulsion load, the controller receives feedback indicating favorable conditions for noise reduction and accordingly operates the refrigeration circuit at reduced capacity, minimizing HVAC noise while maintaining passenger comfort through strategic heat exchanger placement and insulation.
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 reduces perceived noise from the HVAC system by operating at reduced capacity during quiet modes, enhancing passenger comfort without compromising temperature control.
Implementation Method 1
The refrigeration circuit includes an exterior heat exchanger that is supported by the frame, an interior heat exchanger supported by the frame and in fluid communication with the exterior heat exchanger
Data Source
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AI summary
A HVAC system for a vehicle that includes a propulsion system, a frame and a door coupled to the frame. The HVAC system includes a refrigeration circuit and a controller that is operable to detect a condition of the vehicle that includes a load of the propulsion system. The controller is programmed to adjust the refrigeration circuit in response to the sensed temperature of the vehicle and the detected vehicle condition. The controller is programmed to decrease a speed of at least one of the outdoor heat exchanger fan, the indoor heat exchanger fan, and the compressor in response to detection of a high engine load of the vehicle and to increase the speed of at least one of the outdoor heat exchanger fan, the indoor heat exchanger fan, and the compressor that was previously operated at a decreased speed in response to detection of a low engine load of the vehicle.