Find in Library

This paper fully studies the relation between the velocity of ultrasonic wave and the concentration and temperature of urea solution obtained from vehicle exhaust, based on the principle of ultrasonic wave transmitted with different speeds in different concentration solutions.The experiment results show that the velocity of ultrasonic wave transmitted in the urea solution is higher when the concentration of urea solution increases, and indicate that their relationship is obviously linear. Furtherly, experiment results also reveals that the temperature of urea solution has a certain influence on the propagation speed of ultrasonic wave. By using the ultrasonic time-difference method, the temperature compensation, moving average filter and linear regression method, the real-time detection for the concentration of urea solution is achieved, and the error of this detection method is less than 0.5%. The system sends data to the main equipment of Selective Catalytic Reduction(SCR) system through CAN bus, which provides an efficient guidance on vehicle exhaust treatment.