An equipment failure, safety incident or compliance lapse can shut down operations in a hurry. But when you're up and running, what about the thousand other inefficiencies that sap the productivity of people and processes—and chip away at profits?
The right high-performance instrumentation can help boost efficiency and productivity in a number of important ways. Highly accurate instrumentation that remains stable in even the harshest environments can help reduce process variability, and, in turn, allow the process to be operated closer to optimal conditions. New wireless instruments can help root causes of inefficiency that formerly went undetected. Instruments that are easier to engineer, install and use help plant personnel become more productive in their daily tasks. And more complete and readily accessible information can help plant personnel make better decisions in a more timely fashion.
Closing the Loop on Energy Costs
Across the process industries, energy is a significant component of plant operating costs—and all indications are that prices will continue to rise in the long term. In fact, at some petroleum refineries, energy costs already account for a full half of all operating expenditures, according to research from the Lawrence Berkeley National Laboratory's Industrial Energy Analysis. Wireless instrumentation, much of it measuring previously uninstrumented variables, is helping a growing number of companies run more efficiently by providing greater visibility into energy consumption.
For example, at one large U.S. refinery an Emerson Smart Wireless network is gathering temperature measurements in the crude oil pre-heating area. The heat exchangers in the area had been plagued with poor temperature measurements due to degradation of thermocouple and RTD wiring. Operators had to take spot measurements with an infrared gun once a month, and manually enter the readings so heat exchanger efficiencies could be calculated and cleaning schedules developed. As a result, fouled, inefficient exchangers sometimes ran in that manner for weeks at a time between monthly checks.
To improve this situation, ten Rosemount 648 Wireless Temperature Transmitters were installed on the inlet and outlet of the heat exchangers with one-minute update rates. The installation points were hidden behind dense piping, vessels, and tanks, but the wireless mesh network has remained strong with high signal reliability. Now process engineering has live, accurate information at one-minute intervals instead of once a month. Richer information and 43,200 automatically measured and recorded points per month compared to one manually measured and recorded point, gives engineering the tools they need to optimize thermal efficiency.
The instrumentation and control fleet team at another large U.S. power plant sought to improve the efficiency of heat transfer in their feedwater heaters. Controlling the level of the condensate is critical for efficiency and reliability of the steam generation system. If the level is too high, the feedwater tubes are submerged, reducing the heat transfer efficiency. But, if the levels are too low, the steam can blow through without effectively heating the tubes. In addition, it was essential to monitor levels to prevent water induction (or carryover) into the turbine.
These challenges were solved with the Rosemount 5301 Guided Wave Radar (GWR) in combination with the Rosemount 9901 Chamber. Three GWRs in duplicate external mounting assemblies were installed on each of the eleven feedwater heaters. True triple redundancy was achieved through the highly accurate and consistent GWR measurements, which are unaffected by density changes. By improving the stability and accuracy of the feedwater level measurements, the plant operated at feedwater heater levels that increased heat transfer efficiency and reduced the risk of equipment damage.
At Plains Exploration and Production (PXP), an independent oil and gas producer, steam injection is used to enhance recovery from its Hopkins lease property near Bakersfield, Calif. Thermal energy accounts for a large portion of the company's operating expenses, and the steam-to-oil ratio (SOR) is an important optimization parameter. Too little steam and production suffers. Too much steam doesn't just reduce energy efficiency, it also can damage the well liner resulting in lost production and costly repairs.
But because there was no power or communications in the vicinity of the wells, orifice flowmeters connected to mechanical chart recorders were the only means of process feedback. Operators manually recorded data from as many wells as they could visit in a day, and sent that information back to Bakersfield where it was used to make operating decisions.
PXP turned to Emerson Smart Wireless technology to provide the information they needed to measure and optimize steam injection rate in real-time. A mile-square Smart Wireless network and instrumentation including Rosemount 3051S Wireless Pressure Transmitters and Rosemount 8800 Vortex Flowmeters with Smart Wireless THUM Adapters for 120 wells "paid for itself in months," according to Michael Fischback, PXP project facilities engineer. "This technology has opened up new possibilities for us. We plan to continue utilizing wireless technology to improve our oil production, improve our cost position, and make our people more productive."