Vehicle Air Conditioner Compressor Control for Dehumidifying Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In vehicle air conditioners, especially those for hybrid and electric cars, the dehumidifying and cooling mode faces challenges where the temperature of the heat absorber converges at a target value, but the high pressure of the refrigerant circuit does not rise to the target value, leading to a shortage in radiator temperature, necessitating a change in operation mode.
Innovation Solution
The air conditioner includes control means that adjust the compressor capability based on the heat absorber temperature and expansion valve position based on radiator temperature or pressure, executing a radiator temperature prior mode to enhance compressor capability and heat radiation in the dehumidifying and cooling mode, and incorporates an internal cycle mode, electric heater, and blower adjustments to maintain comfortable air conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the valve position of the outdoor expansion valve is controlled based on radiator temperature, then the radiator temperature can be maintained, but the compressor capability becomes insufficient when the high pressure does not rise
Solution Approach 1:
The control method incorporates feedback by continuously monitoring both heat absorber temperature and radiator temperature. Based on this feedback, the system determines whether to operate in standard mode or radiator temperature prior mode, and adjusts the compressor capability target value and expansion valve position accordingly to maintain optimal performance.
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 solution enlarges the effective range of the dehumidifying and cooling mode, ensuring comfortable air conditioning by maintaining adequate compressor capability, preventing frost formation, and optimizing energy use through targeted temperature control and blower adjustments.
Implementation Method 1
a compressor which compresses a refrigerant
Implementation Method 2
a radiator disposed in this air flow passage to let the refrigerant radiate heat
Implementation Method 3
an expansion valve which decompresses the refrigerant flowing into the outdoor heat exchanger
Implementation Method 4
a heat absorber disposed in the air flow passage to let the refrigerant absorb heat
Implementation Method 5
an outdoor heat exchanger disposed outside the vehicle interior to let the refrigerant radiate or absorb heat
Data Source
AI summary
A vehicle air conditioner which can enlarge an effective range of a dehumidifying and cooling mode to realize comfortable air condition in a vehicle interior. A controller changes and executes at least one of a heating mode, a dehumidifying and heating mode, a dehumidifying and cooling mode, and a cooling mode. In at least the dehumidifying and cooling mode, the controller controls a capability of a compressor (2) on the basis of a temperature of a heat absorber (9), and controls a valve position of an outdoor expansion valve (6) on the basis of a temperature or a pressure of the radiator (4), and executes a radiator temperature prior mode to enlarge the capability of the compressor (2), in a case where heat radiation in the radiator (4) runs short.