Vehicle AC Supercooling Control for Stable Cabin Heating
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Solution Overview
Problem
Electric vehicle air conditioning systems face challenges in maintaining consistent interior temperatures and humidity due to variations in refrigerant temperature and heat release across radiators and outdoor heat exchangers, especially when the vehicle is in motion, leading to difficulties in controlling the temperature and humidity settings.
Innovation Solution
The system incorporates a compressor, radiator, heat exchanger, and outdoor heat exchanger, with a target supercooling setting and valve control to regulate the expansion valve's opening, ensuring consistent refrigerant supercooling and condensing pressure, and includes a high-pressure refrigerant flow regulating valve to manage refrigerant flow between the radiator and outdoor heat exchanger, thereby stabilizing the temperature and humidity levels inside the vehicle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the degree of supercooling of the refrigerant is increased to improve radiator radiation performance, then the heat release efficiency improves, but the temperature difference between upstream and downstream refrigerant increases causing air temperature variations
Solution Approach 1:
The patent dynamically adjusts the degree of supercooling of the refrigerant based on operating conditions. By changing the supercooling parameter according to vehicle speed, air flow conditions, and thermal load, the system optimizes heat release efficiency while preventing excessive temperature differences that would cause air temperature variations in the passenger compartment.
Solution Approach 2:
The system implements dynamic control of the refrigerant flow and heat exchange parameters. The degree of supercooling is not fixed but is continuously adjusted based on real-time operating conditions, allowing the radiator to adapt its performance characteristics and maintain stable air temperature output despite varying vehicle speeds and thermal demands.
2Productivity
If the vehicle moves at high speed, then the air flow through outdoor heat exchanger increases improving heat exchange, but the heat release quantity in radiator decreases making it difficult to control interior temperature
Solution Approach 1:
The patent implements a feedback control system that monitors the vehicle speed, air flow conditions, and interior temperature. Based on this feedback, the system adjusts the refrigerant flow distribution between the radiator and outdoor heat exchanger, ensuring that the radiator receives sufficient refrigerant flow even at high vehicle speeds to maintain the desired interior temperature.
Solution Approach 2:
The system dynamically redistributes refrigerant flow between the radiator and outdoor heat exchanger based on vehicle operating conditions. At high speeds, when outdoor heat exchange is enhanced, the system adjusts the refrigerant flow split to maintain appropriate heat release in the radiator, preventing interior temperature control issues.
3Productivity
If the degree of supercooling is increased to improve heating performance, then the radiation performance improves, but frost formation risk increases on heat exchangers
Solution Approach 1:
The patent carefully controls the degree of supercooling within an optimal range that maximizes heating performance while preventing frost formation. By adjusting the supercooling parameter based on outdoor temperature, air flow conditions, and heat exchanger state, the system achieves efficient heat release without causing refrigerant temperature to drop below the frost point on heat exchanger surfaces.
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 effectively reduces temperature variations within the vehicle, ensures consistent heat release during cooling and dehumidifying operations, and prevents frost formation on heat exchangers, even in low outdoor temperatures, maintaining preset temperature and humidity settings.
Implementation Method 1
a compressor configured to compress and discharge a refrigerant
Implementation Method 2
a radiator provided in a vehicle interior and configured to release the heat from the refrigerant
Implementation Method 3
releasing the heat from the refrigerant discharged from the compressor in the radiator
Implementation Method 4
to decompress the refrigerant by an expansion valve
Implementation Method 5
a heat exchanger provided in the vehicle interior and configured to absorb the heat into the refrigerant
Implementation Method 6
an outdoor heat exchanger provided outside the vehicle interior and configured to release the heat from or absorb the heat into the refrigerant
Implementation Method 7
prevents frost formation on heat exchangers, even in low outdoor temperatures
Data Source
AI summary
A vehicle air conditioning apparatus is provided that can prevent temperature variations of the air after the heat exchange in a radiator to reliably control the temperature of the air supplied to the vehicle interior. During the heating operation and the heating and dehumidifying operation, target degree of supercooling SCt when target air-blowing temperature TAO is a predetermined temperature or higher is set to SCt1 that is greater than SCt2 when the target air-blowing temperature TAO is lower than the predetermined temperature. When amount of air Ga supplied from indoor fan 12 is lower than a predetermined value, the target degree of supercooling SCt is corrected, which is set such that the degree of supercooling is lower than target degree of supercooling corrected when the amount of air Ga supplied from the indoor fan 12 is a predetermined value or higher.