Cool air/warm air generation system
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Solution Overview
Problem
Electric vehicles face challenges in efficiently heating and cooling cabins due to the lack of waste heat from engines and the noise and size issues associated with traditional heat pumps, particularly those based on the thermoacoustic effect.
Innovation Solution
A cool air/warm air generation system utilizing an acoustic wave generation unit with a linear motor to oscillate working fluid, transmitting acoustic waves through a transmission tube, and a heat/acoustic wave conversion component with a high cell density and low thermal conductivity material, which selectively generates acoustic waves within a frequency range of 50 Hz to 500 Hz to minimize noise and maximize energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a heat pump compresses or expands working fluid to generate heat, then energy efficiency is improved, but device size increases and complexity increases
Solution Approach 1:
The patent replaces the mechanical compression and expansion system with an acoustic wave-based system. Acoustic waves oscillate the working fluid to achieve heat transfer without mechanical moving parts, thereby maintaining energy efficiency while reducing device size and complexity.
Solution Approach 2:
The patent changes the operating parameters of the working fluid by using acoustic wave frequency and amplitude to control fluid oscillation and heat transfer, instead of using mechanical pressure changes. This allows efficient heat pumping with a compact device.
2Loss of energy
If gas working fluid with high global warming potential is used in heat pump, then energy efficiency is improved, but environmental harm increases
Solution Approach 1:
The patent changes the physical state parameters of the working fluid by using acoustic wave-induced oscillation and phase changes, enabling efficient heat transfer with environmentally friendly fluids that were previously unsuitable for heat pumps.
3Device complexity
If thermoacoustic heat pump is used to reduce device size, then device complexity is reduced, but noise is generated
Solution Approach 1:
The patent converts the potentially harmful acoustic noise into a useful function by using controlled acoustic waves to drive the heat transfer process. The acoustic field that could be perceived as noise is instead utilized to oscillate the working fluid and enable efficient heat pumping with simple device structure.
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 achieves high energy efficiency while maintaining a compact size and reducing noise, effectively heating and cooling electric vehicle cabins without the environmental impact of high global warming potential gases.
Implementation Method 1
an acoustic wave generation unit that includes a linear motor which receives AC power and generates a vibration force in a linear direction, the acoustic wave generation unit oscillating working fluid, that has a pressure of 35 atm or less and oscillates to transmit acoustic waves, with the linear motor so as to generate acoustic waves
Implementation Method 2
a heat pump based on a thermoacoustic effect, as another type of heat pumps which is different in the method of drawing heat from the above-stated heat pump
Implementation Method 3
a cool air/warm air generation unit that obtains first external air and second external air from an outside of the electric vehicle and gives heat of the first external air to the second external air via acoustic waves transmitted through the transmission tube
Data Source
AI summary
An acoustic wave generation unit oscillates working fluid of 35 atm or less so as to generate acoustic waves with a frequency in a range from 50 Hz or more and 500 Hz or less. A heat/acoustic wave conversion component has a partition wall of 5.0 W/mK or less between two end faces which defines a plurality of cells of 620 cells/cm2 or more and 3100 cells/cm2 or less. A heat exchanger disposed close to one end face receives heat from a first external air flowing into the heat exchanger and gives the heat to the one end face so as to flow out a cold air. Another heat exchanger disposed close to the other end face receives heat from the other end face and gives the heat to a second external air flowing into the another heat exchanger so as to flow out a warm air.