Design and experiment study of a novel micro seawater solenoid valve for energy conversion device of marine animal telemetry tag

Abstract

The marine animal telemetry tag is an important ocean environment measurement tool, especially for polar ocean observation. A novel micro seawater solenoid valve is proposed to control the seawater pressure energy conversion device of the telemetry tag. The conversion device is used to replace the lithium battery of the tag to increase its energy supply. Under nearly 1000 m underwater, the solenoid valve and its electromagnet are immersed in high-pressure seawater. To tackle the problems of high pressure, corrosiveness and electrical conductivity of seawater and meanwhile minimize the power consumption and the size, several new designs have been developed, including flexible pressure balancing membranes, the fluid hydrostatic transmission between the spool and the armature, and the dual duty cycle pulse width modulation (DDC-PWM) control circuit. The prototype of the solenoid valve was built and tested. The experiment results show that the micro solenoid valve worked normally in high-pressure water and meanwhile achieved micro size. Furthermore, the experiment results also indicate that the water pressure had almost no influence on the energy consumption of the valve and the valve’s energy consumption is reduced to one-ninth under control of DDC-PWM circuit. Under control of the micro solenoid valve, the energy conversion device achieved expected efficiency and can greatly increase the energy supply of the tag, which extends the tag’s working life and enhance its environmental monitoring capability. Because of micro size and low energy consumption, the valve is applicable for various underwater instruments and has remarkable advantages in deep water.