Dyno Nobel is a global explosives manufacturer. Its site in Louisiana, Missouri, manufactures 54 million lb of packaged explosives and more that 1.2 million tons of ammonium nitrate annually. Powerful production like that requires a lot of energy. Indeed, a 5% reduction equals about $60,000 in savings.
“Dyno Nobel’s utility budget can have a cost variance as high as 10% monthly,” explained Chris Short, Emerson’s field sales specialist for Rosemount Measurement, who spoke this week at the Emerson Global Users Exchange in San Antonio.
“The challenge is meeting monthly electrical budgets with high swing demands,” said Andy Hawkins, I&C engineer at Dyno Nobel’s Missouri facility. “We needed a more granular view of power consumers in the facility, and we needed to be able to measure power usage from the substation.”
Lack of information is the biggest challenge for any type of energy management, so finding a measurement solution that was affordable was the first step. “The big concern was running wire. The distance was cost-prohibitive. We decided to take a top-down strategy and measure each motor control center (MCC) to establish a baseline measurement on a day-to-day basis,” explained Hawkins.
The Dyno Nobel facility has four main operating units with 12 MCCs. “Our MCCs are spread out geographically,” said Hawkins. “I/O solutions were cost-prohibitive. But we have five wireless gateways with about 200 wireless devices. Our plan was to use our existing wireless infrastructure and bring that data into the DeltaV control system via Modbus. Emerson’s 56WM WirelessHART power meter was an easy solution to sell to management because of our existing wireless infrastructure.”
Each MCC is monitored, and, based on analysis of energy usage, the power monitors are then retasked to individual loads within each MCC to give increased granularity as required to find high or unwarranted energy loads.
“The 56WM wireless power meter is meant to measure three-phase or three single-phase,” explained Mike Truitt, senior application engineer for Emerson’s Therm-O-Disc systems. “The 0-600 V native range can be measured. We can look at the load of the entire facility or measure down to each load.”
The devices will scavenge power, so they can be moved around without worrying about the mesh network or WirelessHART. “Dyno Nobel installed two 56WM power meters in the acid-cooling-tower MCC as a method for anticipating equipment failure in cooling fan systems, such as electric motors and attached gear boxes,” explained Truitt. “We can look at imbalances in power. If we have an increased load, we can see that. The power meter directly measures phase currents, phase voltage and frequency over time.”
Based on the measurements, individual phase and system calculations are made for kW, kWh, VA, VAr, VArh, displacement and apparent power factor, as well as total harmonic distortion.
“The system provides real-time power usage,” said Truitt. “We can go through a gateway—Rosemount or DeltaV WIOC—with Modbus TCP, Modbus RTU, EtherNet/IP, OPC or HART to the control room.”
The power monitoring provides increased visibility of where and when electrical costs are incurred, explained Short. “Increased visibility provides actionable information that leads to improvements. The facility looks at assets such as pumps or electrical assets for granularity to trend and track through the DeltaV system. Recent studies show midsize refineries can save 7% of electrical costs by energy management, so their 5% goal is very realistic.”