Hybrid Vehicle Air Conditioning Pump Speed Control
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Solution Overview
Problem
The existing air conditioning systems for hybrid vehicles fail to accurately control the rotational speed of the electric water pump based on the thermal load of the heater core, leading to inefficient circulation of engine cooling water, which affects heat generation and vehicle room temperature, resulting in reduced comfort and engine efficiency.
Innovation Solution
An air conditioning system that includes a discharged air temperature sensing unit and a control unit to calculate the temperature difference between the discharged air temperature and a target discharge temperature, allowing for differential control of the electric water pump's rotational speed and the amount of engine cooling water supplied to the heater core, optimizing heat generation and vehicle room temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the electric water pump's rotational speed is controlled based on the blower's rotation speed level, then the thermal load of the heater core is controlled, but the rotational speed cannot be accurately controlled depending on the actual thermal load
Solution Approach 1:
The patent introduces a feedback mechanism where the control unit continuously monitors the actual thermal load of the heater core and adjusts the electric water pump's rotational speed accordingly. This closed-loop control ensures accurate tracking of thermal load requirements while maintaining system simplicity through electronic control rather than mechanical complexity.
Solution Approach 2:
The patent replaces the mechanical coupling between the blower speed control and water pump speed control with an electronic control system. The control unit processes thermal load information and independently regulates the water pump motor, substituting mechanical transmission with electronic actuation for more precise control.
2Temperature
If the electric water pump operates at high rotational speed to maintain heater core heat generation, then heating performance is improved, but engine cooling water is excessively circulated causing engine temperature reduction
Solution Approach 1:
The patent implements dynamic control of the electric water pump's rotational speed based on real-time thermal load conditions. The control unit continuously adjusts the pump speed to match the actual heating requirements, preventing excessive circulation that would cause unnecessary engine cooling and energy loss while ensuring adequate heat generation when needed.
Solution Approach 2:
The patent changes the operational parameters of the water pump system by independently controlling the pump's rotational speed separate from the blower speed. This allows the system to optimize the balance between heater core temperature maintenance and engine thermal energy conservation by adjusting water flow rate as an independent parameter.
3Ease of operation
If the electric water pump rotational speed is not accurately controlled, then the system structure remains simple, but the vehicle room temperature control and engine efficiency are reduced
Solution Approach 1:
The patent enables the air conditioning system to self-regulate by having the control unit automatically monitor thermal load conditions and adjust the water pump speed without external intervention. This self-service capability improves temperature control accuracy and maintains engine efficiency through automated optimization of cooling water circulation.
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 enables precise control of the electric water pump's rotational speed and engine cooling water circulation, ensuring optimal heat generation, maintaining vehicle room comfort, and preventing excessive engine cooling water circulation, thus enhancing engine efficiency and reducing fuel consumption.
Implementation Method 1
the heater core 7 is configured to receive hot cooling water from an engine 9, thereby allowing the hot cooling water to exchange heat with the ambient air
Implementation Method 2
The blower 3 is configured to draw an internal air or an external air and to blow the same toward an internal passage 1a of the air conditioner case 1
Implementation Method 3
the electric water pump 9a is installed between the heater core 7 and the engine 9. If the motor vehicle is switched from an engine drive mode to a motor drive mode, the electric water pump 9a forcibly pumps the cooling water of the engine 9 and forcibly circulates the cooling water through the heater core 7
Data Source
AI summary
An air conditioning system for hybrid vehicles includes: a heater core receiving engine cooling water from an engine and heat an air blown into a vehicle room; an electric water pump pumping the engine cooling water through the heater core when a motor vehicle is switched from an engine drive mode to a motor drive mode; a discharged air temperature sensing unit sensing a discharged air temperature as a temperature of an air discharged into the vehicle room; and a control unit when the motor vehicle is switched from the engine drive mode to the motor drive mode differentially controls a rotational speed of the electric water pump depending on a temperature difference between the discharged air temperature inputted from the discharged air temperature sensing unit and a target discharge temperature calculated in advance based on internal/external temperature conditions and a user set temperature.