December 2006 Archives

It's that time of year to visit with friends, family, and loved ones. This will be the last post for 2006.

Enjoy your holiday season and I look forward to sharing more stories as 2007 comes rolling in.

For those of you in the northern hemisphere where the snow falls, here's a happy holiday wish to you.

For those in more temperate climates and in the southern hemisphere, here's a happy holiday wish to you.

As much as this pains me to say it, people usually prefer from hearing from other people with experiences to share than from marketing folks. This a big reason for the growth and popularity of supplier user group meetings including our Emerson Exchange.

A personal example of this is when I was shopping for an HDTV and was Googling around for information on the various technologies and products. I found the best source of information in forums (especially avsforum.com) from users that had experiences with a particular technologies and manufacturers. I found these experiences to be more valuable than the product review sites or manufacturer sites.

This is probably why more shopping sites include user comments in addition to product review articles and specs.

I point all this out because there are some very vibrant forums and email lists that have been going on in the automation world. Good examples include Control.com, Fieldbus Online, ISA Technical Discussion and Industry lists to name a few. These are in addition to the many blogs appearing which I try to capture in my right-side blogroll.

Joining this trend of increased knowledge sharing is Mynah Technologies, whose Mimic simulation and integration products are part of many DeltaV system installations. They have rolled out a Mynah Forum area for users of these products and Mynah folks to share ideas, tips, tricks, feedback, etc.

The forums include a blog, MYNAH Experts' Blog, led by Martin Berutti, whom I've known for many years. Martin kicks off his inaugural post, Simulation Objections Answered, discussing common objections to the consideration of simulation as part of process automation projects. He summarizes four objections with his reasons for reconsideration.

Give it a read and feel free to add your thoughts.

Congratulations to Gordon McFarland, senior power plant performance analyst with Emerson's Power & Water Solutions division for receiving the ISA's Standards & Practices Award. The award recognizes Gordon for his leadership in the initial development of fossil power plant standards, and for 25 years of continuous support and direction of those standards.

I caught up with Gordon who has 37 plus years in the power industry helping power producers get the most out of their control systems, including the Ovation system and non-Emerson systems. He applies this expertise as a primary technical lead in Premier Services performance improvement assessments. These assessments typically include a unit walk-down, plant personnel interviews, unit performance data collection, observation of unit operation, analysis of data and information collected, presentation of the results, and a final performance improvement assessment report. The team documents the actual unit control performance for deviation from the set points, control overshoots on ramping, ramp rates, unit net heat rate, forced outages and load de-rates directly and indirectly related to controls, and other parameters that may be important to overall performance.

Since 2000, Gordon has performed assessments on over 50 units, including drum type units, Once-Thru units, coal-fired and gas-fired units. On several of these, the performance was benchmarked by conducting "Before" and "After" performance tests to validate performance improvements on drum units, both coal-fired and gas-fired units, and on combined cycle units.

The goal of these assessments is to give power producers a roadmap to follow to achieve the possible unit performance improvements from improved control of the unit. These recommendations typically include field devices, control systems, operator interfaces, information and alarm management, and control room layout.

One thing Gordon and the team see almost every time in their evaluations is the need to have the basic regulatory control functions covered. This include single element and three element feed water control, steam temperature control, combustion control and unit front end control. The ISA SP 77 Fossil Fuel Power Plant Standards series covers the minimum recommended controls for these functions and they are a great starting point for good power plant control.

By applying his 37+ years of experience, Gordon has helped power producers in analyzing and improving their control performance and operating costs.

Do you ever get the feeling you have to know more and more to do your job?

Control magazine editor-in-chief, Walt Boyes, nails it in a recent blog post when he writes:

We need to be interdisciplinary generalists (wow, there's a mouthful for you) that can do field devices, final control elements, loop control, advanced process control, networking and IT, cybersecurity, safety instrumented systems, plant security and after we master all of that, we're going to find that it still isn't going to be enough.

As process manufacturing plants become smarter and more efficient as more systems and software are integrated and digital technologies are deployed, they also need the planning, engineering, commissioning, and ongoing support to get the most out of them. Most of the posts have discussed aspects of areas Walt mentions with the part of the plant lifecycle where experts have helped.

Now more than 100 posts into this blog, the offer from the inaugural welcome post stands:

Please email me, Skype me, or call me if there are particular people or topics that you would like in this blog.

I saw an email about a success at a northern U.S. paper maker that set a new production record. To whom did they attribute this success? Since this is a blog about the experts around Emerson Process Management, you might guess the answer. And you'd be correct. They attributed their new production record to the work of our Control Performance team and their process and control study process.

I caught up with Andrew Waite, a principal process control consultant on the Control Performance team. Andrew began the study by using the EnTech toolkit which collects data from a variety of sources including pneumatic controllers, 4-20mA analog values, and can import digital data from smart field devices and digital automation systems using the OSIsoft PI data historian. The toolkit performs analysis and tuning recommendations based upon the data it collects.

Andrew noted that he uncovered all of the typical problems: tuning, control strategy issues, control valve problems, and process design limitations. The mill's maintenance department went to work fixing the control valve issues while Andrew provided tuning recommendations and improvements that could be made to the existing control strategies.

The mill attributed the increased production to taking care of the basics and having a fresh set of eyes come in to audit the existing performance. Not too bad for a couple of weeks work.

In an earlier post about fired heater efficiency and reliability, I had spoken with Emerson operations consultant, Chris Forland, on the opportunities for refiners to optimize this energy intensive unit.

Working with engineers in the Rosemount Analytical Gas division, Chris has developed a spreadsheet with fired heater efficiency economic calculations which allows refiners to get a rough estimate of the potential value in applying efficiency solutions like the SmartProcess Heater Optimizer.

You can enter data in the cells with blue text for each fired heater in your plant to get a quick assessment. Chris has filled in typical values from a cross section of refineries in case you don't have exact data. This will let you get a feeling for the overall improvement opportunity and if there is enough return on investment to warrant a closer look.

If you have fired heater units in your manufacturing process, give this calculator a try and let us know what you think by adding a comment or contacting us.

In an earlier post I discussed the critical role the final control element plays in a safety loop or safety instrumented function (SIF) in safety parlance. This equipment mostly stays in one position until called upon to move should an emergency situation arise. Digital valve controllers like the Fieldvue DVC6000 SIS provide partial stroking of the valve to process manufacturers design their safety instrumented functions to reduce the Probability of Failure on Demand (PFD).

Even with the advancement of intelligence in digital valve controllers to do this partial stroke testing, a problem remained in testing the solenoid valves used in the safety instrumented function. These solenoid valves are installed to quickly bleed the air supply to the valve actuator that is holding the SIS valve open or closed. The only real way to test this solenoid valve has been to trip it causing the safety function to occur. These spurious trips can be quite strenuous on the plant piping and process equipment.

Riyaz Ali, a development manager in Emerson's Fisher division showed me the latest advancements to the DVC6000 SIS to test the solenoid without causing safety valve movement. What the technology team found through extensive research and development is that the solenoid valve can be pulsed for a split second by smart SIS logic solvers like the DeltaV SIS system.

This time window of the pulse is long enough for the solenoid valve to vent which provides verification that it is functional. But the time window is short enough so that the actuator does not bleed off enough pressure to make the SIS valve move. Diagnostics in the DVC6000 SIS can sense and capture the data for the momentary pressure blip across the solenoid valve during the test. It also records pressures, travel information, and other diagnostic information.

Beyond solenoid testing, Riyaz mentioned the DVC6000 SIS is capable of collecting data during a trip event, much like an airline's "black box" flight recorder. This data collection can be triggered upon a change in actuator pressure, valve travel, input current, pressure differential, travel deviation, travel cutoff, or an externally defined trigger event. This data can be helpful when reviewing the causes of a safety trip as well as having the data available for regulatory reporting.

One final point Riyaz emphasized is the DVC6000 SIS spurious trip protection which provides maximum output pressure to the solenoid at minimum input signal in a case where the 4-20mA signal between the smart logic solver and digital valve controller is lost or severed.

Together, these technologies give process manufacturers an end-to-end way of checking the safety instrumented functions including the solenoid valves, to assist their design, implementation, and ongoing testing phases of the IEC 61511 safety lifecycle.