Steam Management and Optimization

At the Emerson Exchange conference in Austin, Emerson’s Jim Dunbar presented Steam Management and Optimization. His abstract:

Sipchem facility includes utility plant supplying steam to seven downstream production plants. Utility plant was struggling with reliability issues that had caused a ripple effect throughout the entire facility causing significant production loss. SipChem consulted Emerson and based on recommendations; SmartProcess Header solution was implemented along with improved control strategy and conceptual design for steam load shedding solution. Project was implemented online with no disturbance to plant operation and has delivered a robust and reliable plant wide master header control.

jim-dunbar-emrexJim opened describing the project. Centralized utilities produce steam and power for the complex. It includes 5 boilers and the goal was to enhance plant master responsiveness to plant upsets and improve combustion air controls. The project was done in two phases with 2 boilers in phase 1 and 3 boilers in phase 2.

What was happening is if they had a large upset or trip in the facility the steam headers from the boilers would fight each other and not smoothly handle the upset. The unit trips could ultimately lead to boiler trips. The goal was to improve stability, reliability and availability and make the plant more agile to changes. By optimizing the controls, fuel usage would be reduced and controls simplified for the operators.

The project was done while the plant was running. The first step of the project was to create a medium fidelity simulation of the steam headers and boilers. This allowed scenarios to be performed to see how the control strategy would react to various unit upsets. This work was done on virtual machines including the simulation of the DeltaV control system. Jim noted that he could work on the control strategy while traveling to the site on the plane on his laptop.

A detailed implementation plan was developed and presented to the petrochemical producer staff for review and approval. The control strategy takes the demand requirements of the plant to a main net energy controller which talks to each boiler control master. Ultimately the demand gets divided to each of the boilers on a proportional basis.

The plant master provides total net energy demand for all boilers and the net energy controller allocates and balances total net energy demand between boilers. It considers all boiler limits, ramping capability and efficiency.

Here’s the architecture of the solution:


The solution includes boiler net energy optimization, total boiler net energy control and net energy limiting. The was a dashboard for the operators showing the optimum operating range for each boiler based on current plant steam demand.

You can connect and interact with other optimization experts in the Improve & Modernize group in the Emerson Exchange 365 community.

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Implementing an Effective Alarm Management Program

At the Emerson Exchange conference in Austin Emerson’s Kim Van Camp and exida’s Todd Stauffer presented Seven Steps to a Peaceful Control Room: How to Implement an Effective Alarm Management Program for your DeltaV System. Their abstract:

Has the alarm horn become the nemesis of your operators? This presentation describes how to create (build) an effective and sustainable program using ISA-18.2’s alarm management lifecycle (the blueprint) and DeltaV’s alarm management capabilities (the tools). It shows how following the program will allow you to address common alarm management issues (alarm overload, nuisance alarms, alarm floods, incorrectly prioritized alarms) and create a control room environment that maximizes operator performance, improves process safety, and drives operational discipline.

exida's Todd StaufferTodd opened showing an operator screen overflowing with alarms. So many, that it would be difficult for an operator to know what actions to take. The purpose of an alarm is to make operators aware of abnormal situations in order to take corrective action before unplanned shutdowns or slowdowns occur.

He shared a pump leak example where a high level nuisance alarm for a sump pump caused the operators to ignore the alarm when a leak occurred. The leak was not detected until inspection rounds were performed.

Todd discussed the ISA 18.2 alarm standard that describes what to do, but not how to do it. A series of ISA 18.2 technical reports share some of the “how to do” recommendations. The standard defines an alarm that notifies the operator of an abnormal situation which requires a timely response. If it doesn’t require a response, it is not an alarm.

Notifications including alerts and prompts should be put into different categories and displayed differently that the alarms and not be in the alarm summary page. So how do you create and effect alarm program? Here are the steps:

  1. Benchmark initial performance
  2. Create an alarm philosophy
  3. Rationalize the alarms
  4. Implement rationalization results/create alarm response procedure
  5. Implement alarm suppression
  6. Measure performance (monthly)
  7. Audit

kim-van-camp-emrexKim shared some alarm performance key performance indicators such as average alarms per day, alarm rates, peak alarms in 10-minute time windows, etc. DeltaV Analyze takes the alarm log to generate these KPIs. The KPIs can also be provide as service from the Emerson Lifecycle Services team.

Todd discussed some of the content in an alarm philosophy per the ISA-18.2-2016 update. Additions were made in the recent standard update to include an alarm system management audit, alarm shelving and more.

All alarms should meet the criteria of if the alarm really should be an alarm based on the alarm philosophy. If it doesn’t meet the criteria, it should be reclassified to some other level of notification.

Alarms should be prioritized based on the consequences of what would happen if the operator does not respond to it. A matrix should be developed to classify the alarms into priority levels. Priority levels above a threshold should be the ones that appear in the alarm summary.

Todd noted one of the game changers to managing alarms during operations is alarm suppression, shelving and out of service. Examples of situations where the alarms should be put into one of these states include non-commissioned devices, transmitters malfunctioning, out of services. Todd noted that shelving is like hitting the snooze button on a wake up alarm. There is a time and place to shelve alarms based on a condition, such as a chattering alarm where the alarm is not at a critical alarm.

The standard mandated that all distributed control systems have this shelving capability.

Exida’s SILAlarm works with the DeltaV system to help guide the alarm rationalization process. The information collected can be pushed back into DeltaV to offer recommendations on actions to take in response to alarms.

Kim described DeltaV Alarm Mosaic to help manage alarm floods via alarm flood suppression. It graphically shows causality.

The good news is that this workshop is being filmed and will appear in the Emerson Exchange 365 community in the DeltaV group. If you haven’t already joined, please do and you’ll receive a notification when the video is posted.

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Video Recap from Day 3 at Emerson Exchange

Here are video recaps of days 1 and 2.

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Energy Harvesting for Wireless Device Power

At the Emerson Exchange conference in Austin, Emerson’s Josh Hernandez and Perpetua’s Andy Zaremba presented, Energy Harvesting Application- Anything is Possible. Their abstract:

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.

josh-hernandez-power-puckThe 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.

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Selecting the Right Valve

At the Emerson Exchange conference in Austin, Emerson’s Tony Foster and Leah Stanley and Vinson Supply’s Robert Lange presented, Selecting the Right Valve for Your Application to Reduce Cost and Increase Performance. Their abstract:

Selecting the optimum valve for the application can sometimes be a daunting task, even with a “simple” on/off valve, especially when the process operates at high or low temperatures and/or has high levels of particulate. This workshop will cover process variables that should be considered when selecting a valve. Also, the merits and tradeoffs of each valve type will be discussed in order to understand how to best reduce cost and increase performance.

Tony by stating the objective of providing guidance on how to select the right valve for your application. The wrong valve can be costly in terms of safety, downtime, maintenance and more. Here are some important factors:

Valve Selection Criteria

Gate valves provide is a multi-turn valve. The common type is a wedge gate valve. Advantages are less pressure loss, good bi-direction sealing, less energy to close since perpendicular to the flow. Disadvantages are long opening and closing times, large area to operate and maintain. Operates in fully open and close modes and not in throttling applications.

Globe valves have good sealing performance, used for cross throttling, stroke is shorter than gate valves. These valves have a great pressure drop than gate valves.

Butterfly valves are small, lightweight and have fewer to maintain than other valve types. Disks are always in the flow increasing the pressure drop. The seats wear more since they are always in the flow stream.

Triple Offset Valves are small and lightweight and are suitable for many types of fluids. Ball valves provide tight closure and are smaller and lighter that gate valves. They are not suitable for sustained throttling applications.

Valve selection criteria include: size, temperature/pressure, media, required standards, cycle-speed / number, manual or automated, flow rate & direction, and process characteristics. These criteria must be considered in parallel when selecting a valve.

Robert walked through each of these criteria against the valve types. You can find more on these criteria and valve types in chapter 5, Control Valve Selection in the Fisher Control Valve Handbook. The isolation valves are being reviewed to see how the handbook and Specification Manager tool can be updated to include them.

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