PWM Three-Way Solenoid Valve for Cabin Coolant Bypass Mixing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle cabin air temperature control systems are inefficient due to the complexity and high cost of three-way modulating valves, which are needed to modulate coolant temperature for effective air recycling in vehicle cabins.
Innovation Solution
A pulse width modulated two-position three-way solenoid valve is used to control the flow of coolant between a cooling leg and a bypass leg, with a proportional-integral-derivative (PID) controller and pulse width modulator to adjust the coolant temperature based on the difference between the desired cabin temperature and the current air temperature, allowing for efficient cooling and recirculation of air.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a three-way modulating valve is used to modulate coolant temperature, then effective air recycling and temperature control is achieved, but device complexity and cost increase
Solution Approach 1:
The patent divides the coolant flow control into two separate two-position three-way solenoid valves instead of using one complex three-way modulating valve. Each solenoid valve controls a specific leg (cooling leg or bypass leg), simplifying the individual valve components while achieving the same overall flow modulation function through coordinated operation of multiple simpler valves.
Solution Approach 2:
The system uses pulse width modulation (PWM) to dynamically control the duty cycle of the solenoid valves, enabling continuous modulation of coolant flow between the cooling leg and bypass leg. This dynamic control approach allows precise temperature regulation using simple on/off valves rather than requiring a complex continuously modulating valve mechanism.
2Temperature
If a three-way modulating valve is used to modulate coolant temperature, then effective air recycling and temperature control is achieved, but cost increases
Solution Approach 1:
The patent segments the flow control function into multiple simple two-position three-way solenoid valves, which are commercially available off-the-shelf components. This segmentation allows the use of inexpensive, standardized valves rather than a custom or specialized three-way modulating valve, significantly reducing component cost while maintaining the required temperature control functionality.
Solution Approach 2:
The system employs inexpensive two-position three-way solenoid valves that can be easily manufactured and replaced if needed, rather than using expensive three-way modulating valves. The simplicity and standardization of the solenoid valves make them more cost-effective for manufacturing and maintenance.
3Temperature
If pulse width modulation is used to control solenoid valve flow, then precise temperature control is achieved, but control system complexity increases
Solution Approach 1:
The system uses periodic pulse width modulation signals to control the solenoid valves, switching them on and off at high frequency to achieve average flow control. This periodic switching approach enables precise temperature regulation through simple digital control signals rather than requiring complex analog modulation mechanisms.
Solution Approach 2:
The control system incorporates temperature sensors and a PID controller that continuously monitor coolant or cabin air temperature and adjust the PWM duty cycle accordingly. This feedback mechanism enables precise temperature control using simple on/off solenoid valves, as the closed-loop control compensates for the binary nature of the valves.
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 provides efficient and cost-effective control of vehicle cabin air temperature by using a simpler and less expensive two-position three-way solenoid valve, improving passenger comfort and reducing operational costs while maintaining effective air recycling.
Implementation Method 1
A pulse width modulated two-position three-way solenoid valve is used to control the flow of coolant
Implementation Method 2
A cabin air heat exchanger cools down and recycles air that has been warmed in the vehicle cabin
Implementation Method 3
A pulse width modulated two-position three-way solenoid valve is used to control the flow of coolant, with a proportional-integral-derivative (PID) controller and pulse width modulator to adjust the coolant temperature
Data Source
AI summary
A vehicle cabin air temperature controller includes a two-position three-way solenoid valve with one inlet to take in coolant from a pump, a first outlet to supply a cooling leg, and a second outlet to supply a bypass leg. The vehicle cabin air temperature controller also includes a controller to control flow of the coolant via the first outlet and the second outlet of the solenoid valve, and a cabin air heat exchanger to obtain an input coolant based on the control of the flow via the first outlet and the second outlet and to provide cooled cabin air to the vehicle cabin. The control of the flow of the coolant via the first outlet and the second outlet controls a temperature of the input coolant.