Vehicle Air Conditioner Restart Control for Short Stop Cooling
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Solution Overview
Problem
Vehicle air conditioners face inefficiencies in fuel-saving when the stop time of the vehicle is short, as the cold energy stored during traveling is not fully utilized, leading to a shortened compressor stop time and reduced fuel-saving effect.
Innovation Solution
An air conditioner system that includes a target temperature setting unit, compressor control unit, and traveling state determination unit, which sets a modified target temperature higher than normal during deceleration and controls the compressor to stop and restart based on this temperature, ensuring effective use of stored cold energy even during short stops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the compressor stop time is extended to save fuel during vehicle stops, then fuel efficiency improves, but the cold energy stored in the evaporator may not be fully utilized when stop time is short, reducing the effectiveness of the fuel-saving strategy
Solution Approach 1:
The patent dynamically adjusts the compressor restart timing based on the actual stop duration. When the vehicle stop time is short, the system modifies the restart conditions to ensure cold energy is fully utilized before the vehicle resumes operation, thereby resolving the contradiction between extending compressor stop time for fuel savings and ensuring cold energy is effectively used.
Solution Approach 2:
The system changes the control parameters for compressor operation based on detected stop duration. By monitoring whether the stop time exceeds a predetermined threshold, the controller adjusts the restart timing parameters accordingly, allowing optimal fuel savings during long stops while ensuring cold energy utilization during short stops.
2Quantity of substance
If the compressor is controlled to stop during vehicle deceleration to store cold energy, then cold energy storage improves, but the cooling temperature may fluctuate, affecting cooling performance
Solution Approach 1:
The patent implements a feedback control mechanism where the controller continuously monitors the cooling temperature and adjusts the compressor restart timing based on actual temperature conditions. This feedback loop ensures that the compressor restarts at the appropriate moment to maintain stable cooling temperature while maximizing cold energy storage during deceleration.
Solution Approach 2:
The system performs preliminary cooling before vehicle stop or deceleration by controlling the compressor to operate in advance, storing cold energy in the evaporator. This preliminary action ensures that sufficient cold energy is available when the compressor needs to stop, maintaining temperature stability without compromising cold energy storage.
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 approach allows for extended compressor stop time, enhancing fuel-saving by effectively utilizing stored cold energy, even during brief vehicle stops, thereby improving the overall fuel-saving effect.
Implementation Method 1
a cooling heat exchanger configured to exchange heat between air to be blown into an interior of the vehicle and a refrigerant of a refrigerant cycle, and to cool the air
Implementation Method 2
a compressor driven by an engine of the vehicle to compress and discharge a refrigerant of a refrigerant cycle
Data Source
AI summary
In a vehicle air conditioner, a controller is configured (i) to set a target cooling temperature of air cooled by a cooling heat exchanger, (ii) to control an operation of a compressor based on a cooling temperature and the target cooling temperature of the cooling heat exchanger, and (iii) to determine a traveling state of the vehicle. The controller is configured to set a normal target temperature as the target cooling temperature when the vehicle is traveling with a normal condition, and to set a modified target temperature higher than the normal target temperature as the target cooling temperature when the vehicle starts decelerating. In addition, the controller is configured to cause the compressor to stop operating when the vehicle starts decelerating, and to cause the compressor to restart operating when the cooling temperature detected by a temperature sensor is equal to or higher than the modified target temperature.