Wireless instrumentation allows companies to add points of measurement quickly and inexpensively, but battery-powered wireless transmitters present problems. Fast data rates deplete battery life and cold weather cuts battery life, and replacing batteries in hazardous areas is difficult. Energy harvesting devices address these issues by generating sufficient power to keep wireless transmitters running, even at high data rates in cold climes. This session shows how energy harvesting devices have helped several companies, and provides information for others looking to implement similar solutions.
Josh opened discussing the chief concern with wireless plant devices—how long will the battery last? Power Puck technology can be added that powers the device with the battery used as a backup. The Power Puck generates electrical power from anything that’s “warm to the touch”. Unlike a solar cell, it takes heat instead of light to transfer thermal energy into electrical energy.
The technology is mature, reliable and proven being used by NASA to power satellites in deep space where light energy is too faint to be a power. NASA used the heat from decaying Plutonium 238 as the heat source that the Power Pucks converted into electrical energy.
So how much temperature is needed? If there is a 40C difference, there is full power out of the Power Puck. The Power Puck is placed on a heat source such as a pipe or other heat source surface and a wire connects it to the transmitter at the 7.2V that the battery operates at. The solution is intrinsically safe and can operate in Class 1, Div 1 hazardous areas. It has the same certifications as the wireless transmitters.
Heat sources might include pumps & motors, compressors, machine casings, junction boxes, etc.
Like wireless transmitters, these Power Pucks have been adopted into upstream oil & gas applications, such as steam injection enhanced oil recovery.
Another great application Andy highlighted was using AMS 9420 wireless vibration transmitters monitoring a pump and associated motor. The heat generated by the motor and pump powered the transmitters and allowed these transmitters to be set to the fastest update rates.
Monitoring steam flow is another ideal application since the steam lines have such a large temperature differential with ambient temperature. The Rosemount 8800D vortex flowmeter with Wireless THUM and the Power Puck provide a constantly powered solution.
You can connect and interact with other wireless experts in the Wireless group in the Emerson Exchange 365 community.