EV Air Conditioner Condenser Control for Hot Refrigerant Stops
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Solution Overview
Problem
In electric vehicle air conditioner systems, refrigerant leakage and decreased cooling performance occur due to increased compressor temperature, which is caused by high refrigerant temperatures being supplied to the compressor when the vehicle stops after sudden acceleration or when the air conditioner is turned off, leading to seal deterioration and reduced fuel efficiency.
Innovation Solution
A control method that integrates a water-cooled condenser in the intercooler radiator and an air-cooled condenser in the cooling system, with the actuation of a water pump and cooling fan controlled based on air conditioner pressure and cooling water temperature to prevent high-temperature refrigerant from being supplied to the compressor, thereby maintaining seal integrity and improving condensing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the vehicle stops after sudden acceleration or stops after traveling with the air conditioner turned off, then heat accumulated in the intercooler flows into the radiator causing cooling water temperature increase, but the refrigerant cannot be cooled properly and high-temperature refrigerant flows into the compressor causing seal deterioration and refrigerant leakage
Solution Approach 1:
The control method detects stop conditions (sudden acceleration followed by stop, or stop after traveling with AC off) and preemptively controls the water pump and cooling fan to maintain cooling water flow and temperature. This preliminary action prevents high-temperature refrigerant from entering the compressor before the temperature problem can cause seal deterioration
Solution Approach 2:
The system continuously monitors cooling water temperature and air conditioner pressure, and based on this feedback, dynamically adjusts water pump actuation speed and cooling fan operation. This feedback mechanism ensures refrigerant temperature remains within safe limits for compressor operation while maintaining seal integrity
2Reliability
If the cooling fan and water pump operate at high speed to cool the refrigerant, then condensing efficiency improves, but power consumption increases
Solution Approach 1:
The control method dynamically adjusts the actuation speed of the water pump and the operation of the cooling fan based on real-time cooling water temperature and air conditioner pressure conditions. Instead of operating at constant high speed, the components modulate their speed to maintain optimal condensing efficiency while minimizing power consumption during vehicle operation
Solution Approach 2:
The system changes operational parameters (water pump speed, fan speed) based on detected conditions such as cooling water temperature and AC pressure. This parameter adjustment allows the system to maintain efficient condensing when needed while reducing energy consumption during normal operating conditions
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
Prevents refrigerant leakage and maintains cooling performance by controlling the water pump and cooling fan speeds, reducing compressor power requirements and enhancing fuel efficiency by preventing refrigerant temperature increase during vehicle stops.
Implementation Method 1
a water-cooled condenser embedded in an intercooler radiator and configured to condense a refrigerant by receiving cooling water from a cooling system cooling an engine and an intercooler with the cooling water
Implementation Method 2
an air-cooled condenser placed in front of the intercooler radiator and configured to condense the refrigerant supplied from the water-cooled condenser through heat-exchange with outdoor air
Implementation Method 3
actuating the cooling fan to cool the cooling module, into which the cooling water having an increased temperature is introduced, by blowing wind together with the outdoor air while cooling each of the engine and the intercooler
Implementation Method 4
driving the water pump so that the cooling water is circulated to the engine and the intercooler from the engine radiator and the intercooler radiator of the cooling module
Data Source
AI summary
A control method of an air conditioner system for an electric vehicle may include circulating the refrigerant by sensing actuation of the air conditioner system while driving the electric vehicle in a state where a start of the electric vehicle is turned on, circulating and cooling the cooling water through actuation of a water pump and a cooling fan in a cooling module that includes an engine radiator, the intercooler radiator, the water-cooled condenser, and the air-cooled condenser, and controlling actuation speeds of the water pump and the cooling fan based on whether the electric vehicle stops after suddenly accelerating in a state where the air conditioner system is actuated or stops in a state where the air conditioner system is turned off after travelling, and/or based on whether an air conditioner pressure and a cooling water temperature are within predetermined set values.