Method for managing a thermal management device for a motor vehicle
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Solution Overview
Problem
The existing thermal management devices for motor vehicles can suffer from increased pressure in the first evaporator and excessive refrigerant fluid temperature at the compressor outlet when exclusively used to cool electronic and/or electrical elements, potentially damaging the first evaporator and compressor.
Innovation Solution
A method for managing a thermal management device with a refrigerant circuit that includes a main loop and a bypass branch, where the opening diameter of the first expansion device is adjusted based on ambient temperature, and the compressor speed is managed to maintain a set temperature, with additional steps to control the superheat of the refrigerant fluid at the compressor inlet, including the use of electronic expansion valves to prevent overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the thermal management device uses only the second evaporator to cool electronic elements, then the cooling efficiency for electronic elements is improved, but the pressure in the first evaporator increases and may damage it
Solution Approach 1:
The patent implements dynamic control of the first expansion device opening diameter based on ambient temperature. When the second evaporator is exclusively used for cooling electronic elements, the system adjusts the first expansion device to maintain appropriate pressure in the first evaporator, preventing damage while allowing the second evaporator to operate at full capacity for high-performance cooling of electronic components.
Solution Approach 2:
The system changes the opening diameter parameter of the first expansion device according to ambient temperature conditions. At higher ambient temperatures (above 25°C), the opening diameter is reduced to 5% of maximum, while at lower temperatures (25°C or below), it is increased to 20% of maximum, thereby regulating pressure in the first evaporator to prevent damage during exclusive use of the second evaporator.
2Productivity
If the second evaporator is used exclusively to cool electronic elements, then the cooling performance for electronic elements is improved, but the refrigerant fluid temperature at the compressor outlet may become excessively high and damage the compressor
Solution Approach 1:
The system implements feedback control by monitoring the superheat of refrigerant fluid at the second evaporator outlet and adjusting the opening diameter of the first expansion device accordingly. When superheat exceeds the setpoint, the system opens the first expansion device to allow refrigerant to pass through the first evaporator, which cools the refrigerant and reduces superheat, thereby protecting the compressor from excessive temperature while maintaining the second evaporator's exclusive cooling function for electronic elements.
Solution Approach 2:
The first evaporator serves as an intermediary cooling path for the refrigerant fluid. When the second evaporator operates exclusively for electronic element cooling, the first evaporator acts as a mediator to cool the refrigerant fluid passing through it, reducing the temperature and superheat of refrigerant before it reaches the compressor, thus protecting the compressor from thermal damage.
3Reliability
If the opening diameter of the first expansion device is increased, then the refrigerant flow through the first evaporator is improved, but the cooling efficiency for electronic elements may be reduced
Solution Approach 1:
The system dynamically adjusts the opening diameter of the first expansion device based on ambient temperature and operational conditions. By optimizing the opening diameter to specific percentages (5% or 20% of maximum) based on temperature, the system maintains sufficient refrigerant flow through the first evaporator for protection while minimizing the impact on the second evaporator's cooling efficiency for electronic elements.
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 method effectively reduces the risk of damage to the first evaporator and compressor by managing the refrigerant flow and temperature, ensuring the refrigerant fluid does not reach harmful temperatures, thereby enhancing the reliability and longevity of the thermal management system.
Implementation Method 1
a first expansion device and a first evaporator configured to exchange heat energy with a second element
Implementation Method 2
a condenser configured to exchange heat energy with a first element
Implementation Method 3
a second evaporator arranged downstream of the second expansion device and configured to exchange heat energy with a third element
Implementation Method 4
a compressor
Implementation Method 5
a second expansion device and a second evaporator arranged downstream of the second expansion device
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The present invention relates to a method for managing a thermal management device (1) for a motor vehicle, comprising a refrigerant-fluid circuit comprising: - a main loop (A) comprising, in the direction of circulation of the refrigerant fluid, a compressor (3), a condenser (5) configured to exchange heat energy with a firsst element (100), a first expansion device (7) and the first evaporator (11) configured to exchange heat energy with a second element (200), - a bypass leg (B), said bypass leg (B) comprising a second expansion device (13) and a second evaporator (15) positioned downstream of the second expansion device (13) and configured to exchange heat energy with a third element (300), said thermal management device (1) operating in a mode of strict cooling of the third element (300), said management method comprising a step of managing the diameter of opening of the first expansion device (7) as a function of the ambient temperature so that refrigerant fluid circulates within the first evaporator (11), the diameter of opening of the first expansion device (7) decreasing as a function of the increase in the ambient temperature of the first element (100).