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Category Archives: Case Studies

 
See the article in Power Engineering here!
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Upgrading or replacing a boiler system presents one of the most daunting and expensive challenges a large facility can undertake. When the time comes—whether the current system is outdated and inefficient or it fails outright—facility management must understand the process in order to set facility management goals and make the right decisions to fulfill their energy and efficiency needs. More than 1,200 Veterans Administration medical centers and outpatient sites across the country are undertaking system overhauls like this.

Driven primarily by environmental concerns, the VA has undertaken boiler system upgrades in all their facilities. Most of the facilities will need to update their equipment, but some will require a full-system replacement. With more than a thousand facilities in need of evaluation, it’s a huge undertaking—but administrators believe that the long-term savings will make the effort worthwhile.

Why make the change now?

One of the driving factors in getting this change implemented right away is regulatory. California, Texas, and New Jersey have implemented air quality standards that will not be met by older boiler systems. They must be upgraded or replaced.

These old systems often used technology that sacrificed environmental safety in favor of cost savings. Some systems incorporated metal mesh burners, which utilized filters that clog easily. The gradual clogging of air filters leads to less excess air, which leads to higher NOx emissions. NOx emissions are a combination of nitric oxide (NO) and oxygen. Nitric oxide is the result of fuel combustion and alone is not considered hazardous; however, combined with oxygen it is the source of fog, acid rain, and ground level ozone, which has been linked to myriad health issues. And while some other systems might have utilized technology to reduce overall NOx, these systems had increased electricity costs.

A second reason for the VA system upgrade, therefore, is to address these cost concerns. Today’s upgrades do not require air filters, which used to add to operation costs. Upgraded systems also offer quick-change, dual-fuel capabilities, switching between gas and oil firing in less than three minutes. This saves on service costs, since multiple people are no longer needed to make the changeover. The greatest cost reduction, however, is in the demand for electricity. There is a reduction of up to 60 percent in electric consumption.

One way to realize a cost savings is by employing a system that allows one to adjust the output according to the demand. This adjustment is achieved via what is called the unit’s “boiler turndown ratio,” which is the ratio of the maximum heat output to the minimum heat output at which the boiler will operate both efficiently and controllably. As the desired temperature/pressure point is reached, the heat source is turned down, and if the temperature/pressure falls, the heat is turned up. In applications like the VA centers, which require boilers to operate at a low proportion of their maximum output, a high turndown ratio is desired, and that can be achieved with modern upgrades. Traditional burners using fiber metal mesh provide a 3:1 turndown; however, with recent advancements in the field, there are now systems that can provide a 9:1 turndown or higher depending on NOx requirement. These systems can achieve ultra-low NOx emissions without the use of FGR (flue gas recirculation).

In addition to the cost savings realized through a 9:1 turndown, there is also the reduction in required maintenance. Not only are multiple people no longer needed for a dual-fuel changeover, but operating and monitoring the systems are also simplified. Older systems require constant maintenance to ensure fuel efficiency and emission control. For example, many older systems include jackshaft linkage. Due to the complexity of these systems, they require constant fine-tuning and maintenance by highly skilled operators. Maintenance of an upgraded or new system is far less complex.

Newer monitoring equipment also means fewer people are needed for hands-on examination of the system. Typically, with an older system, there was a boiler in each building—and that meant someone needed to be on location to monitor those systems. The ability to house the entire system in one location, or to upgrade the system to monitor from one location, results in lower maintenance costs.

Upgrade or replace? A case study

Determining whether to upgrade or replace a system depends on two things: the age of the existing boiler(s) and the application for the new system. Generally, systems that have been in service for 25 to 30 years would require replacement instead of an upgrade. This was the case for the V.A. Erie Medical Center in Erie, Pennsylvania. Their system had been in place for three decades and required complete replacement. In order to make the most impact with this important project, they built an entirely new boiler plant from the ground up.

The engineering team at the VA determined that existing system had met its lifespan, and they wanted to replace with latest technology. Any short-term replacement would have simply been a Band-Aid. They realized, however, that a project of this magnitude would take time to do properly. The engineering team at the VA chose Greenland Enterprises, Inc. to handle the entire project based on their central plant expertise and track-record at other healthcare facilities.

Based on the campus steam load, they determined that the replacement equipment would consist of two 400-horsepower boilers and one 200-horsepower boiler. Installation of the new boiler system took four months. From the ground up (including the new construction), the work on the project took 14 months to complete.

This new plant will provide at least a 60 percent reduction in electricity consumption, which will be accomplished using a variable frequency drive. This technology can run with fan speed at a lower rate. For example, changing the power from 60hz to 30hz speed can cut the horsepower by eight times. Therefore, a 400-horsepower system would be cut to 60-horsepower. According to Steve Seckler, Vice President of Operations at Greenland Enterprises, “Most systems can go from 60hz to 40hz easily. We chose a system that can efficiently go all the way from 60hz to 15hz for additional savings.”

Fuel reduction provides cost savings over the life of the new system. Newer boiler systems can offer a savings of two to five percent. This means that one 400-horsepower boiler with a fuel cost of $500,000 annually can save between $10,000 and $25,000 a year. This new Erie plant, with its two 400-horsepower boilers and one 200-horsepower boiler, will save the hospital between $25,000 and $62,500 in fuel costs annually.

Is it time for an upgrade at your facility?

A boiler upgrade project like the one undertaken at the VA Erie Medical Center is clearly something that takes significant time and money to complete. But in the end, management determined that the expense and effort will pay off in the long run. Could it be time for you to look at a similar project for your facility? Here are some points to consider when making your decision.

Sustainability

In large facilities, sustainability can be neglected when considering boiler systems. Facilities like hospitals often rely on older boilers and choose the “Band-Aid” approach of patching and maintaining them out of necessity. This method is not sustainable. Upgrading to a new boiler is the best option for long-term, sustainable improvement.

Sustainability also refers to the environmental impact of a system. With ever-changing state requirements, it is important to choose a system with enough flexibility to face these new demands as well as future ones.

Fuel-efficiency

To sufficiently meet the heating and energy load demands of healthcare facilities, old boilers burn an inordinate amount of fuel. New boilers bring added efficiency and substantial fuel savings. There is also much being done in the realm of alternative fuels for boiler systems. Bio-fuels and liquid wood are two segments of the alternative fuel market that are making great strides.

Operations and Maintenance

New boilers are streamlined to operate more smoothly and efficiently than old boilers, which can be challenging to operate and maintain. The older boilers often take much longer to heat up, and they are often kept running to meet heating needs. New boilers are designed to heat up quickly and can be adjusted to handle variable loads to ensure less energy consumption.

When considering an upgrade or replacement, no matter what the reason may be, all factors of the operation need to be addressed in preparation for a system shut-down. A project of this magnitude, from the initial bid process to completion, will require a minimum of several months (for an upgrade) up to a year or more (for a complete boiler replacement). The impact of this change, and thus the importance of the decisions made during the process, are why so many V.A. hospitals and medical centers are carefully reviewing their future energy options.

About the author: Dan Wallace is Vice President of Research & Development at Preferred Utilities Manufacturing Corporation, an engineering-based manufacturer of products for commercial, institutional, industrial and nuclear power facilities.

 

By David Bohn

Read the article in Facilities Manager here!

Upgrading or replacing a boiler system presents one of the most daunting and expensive challenges a large facility can undertake. When the time comes—whether the current system is outdated and inefficient or it fails outright—facility management must take the time to fully understand the process in order to set facility management goals and make the right decisions to fulfill their energy and efficiency needs. Right now, a substantial number of colleges and universities, as well as more than 1,200 Veteran’s Administration medical center campuses across the country, are all undertaking system overhauls like this.

These system upgrades are driven primarily by environmental concerns. Most of the facilities will need to update their equipment, but some will require a full-system replacement. It’s a huge undertaking—but most administrators believe that the long-term savings will make the effort worthwhile.

Why make the change now?

One of the driving factors in getting this change implemented right away is regulatory. California, Texas, and New Jersey have implemented air quality standards that will not be met by older boiler systems. They must be upgraded or replaced.

These old systems often used technology that sacrificed environmental safety in favor of cost savings. Some systems incorporated metal mesh burners, which utilized filters that clog easily. The gradual clogging of air filters leads to less excess air, which leads to higher NOx emissions. NOx emissions are a combination of nitric oxide (NO) and oxygen. Nitric oxide is the result of fuel combustion and alone is not considered hazardous; however, combined with oxygen, it is the source of fog, acid rain, and ground level ozone, which has been linked to myriad health issues. And while some other systems might have utilized technology to reduce overall NOx, these systems had increased electricity costs.

A second reason for a system upgrade, therefore, is to address these cost concerns. Today’s upgrades do not require air filters, which used to add to operation costs. Upgraded systems also offer quick-change, dual-fuel capabilities, switching between gas and oil firing in less than three minutes. This saves on service costs, since multiple people are no longer needed to make the changeover. The greatest cost reduction, however, is in the demand for electricity. There is a reduction of up to 60 percent in electric consumption.

One way to realize a cost savings is by employing a system that allows one to adjust the output according to the demand. This adjustment is achieved via what is called the unit’s “boiler turndown ratio,” which is the ratio of the maximum heat output to the minimum heat output at which the boiler will operate both efficiently and controllably. As the desired temperature/pressure point is reached, the heat source is turned down, and if the temperature/pressure falls, the heat is turned up. In large campus applications, which require boilers to operate at a low proportion of their maximum output, a high turndown ratio is desired, and that can be achieved with modern upgrades. Traditional burners using fiber metal mesh provide a 3:1 turndown; however, with recent advancements in the field, there are now systems that can provide a 9:1 turndown or higher depending on NOx requirement. These systems can achieve ultra-low NOx emissions without the use of FGR (flue gas recirculation).

In addition to the cost savings realized through a 9:1 turndown, there is also the reduction in required maintenance. Not only are multiple people no longer needed for a dual-fuel changeover, but operating and monitoring the systems are also simplified. Older systems require constant maintenance to ensure fuel efficiency and emission control. For example, many older systems include jackshaft linkage. Due to the complexity of these systems, they require constant fine-tuning and maintenance by highly skilled operators. Maintenance of an upgraded or new system is far less complex.

Newer monitoring equipment also means fewer people are needed for hands-on examination of the system. Typically, with an older system, there was a boiler in each building—and that meant someone needed to be on location to monitor those systems. The ability to house the entire system in one location, or to upgrade the system to monitor from one location, results in lower maintenance costs.

Campuses making the changes

Higher education is becoming a competitive industry and honestly, who chooses a college or university because of how new the boiler equipment is? The utility plant is seen as a cost, and universities generally choose to invest in new buildings or facilities that will help them attract students. But with environmental awareness now a prominent part of the national discussion, universities are starting to see the value (both economic and otherwise) to going green. Here are a few examples:

A small, elite liberal arts college in Duchess County NY was working with old boilers that essentially could not fire. To fix the problem, they chose new burners that were compatible with their old boilers which saved them a great deal of money since they didn’t need to replace the whole system. They also replaced their vacuum condensate system for further modernization and efficiency. They are now planning to buy a second burner and are interested in a solution that burns liquid wood.

A prestigious medical school outside of Boston invested in new burners. Their solution provider helped them with reliable low life cycle cost/best value payback on their low pressure steam boilers by providing three 800 HP burners and a feedwater system. They burn natural gas with #2 oil as a back-up, and are actively considering carbon neutral fuels.

The campus heating plant main boiler suffered from several crippling issues at a large public college campus in upstate NY. Working with a vintage 600 HP steam boiler, the burner had a triplex nozzle system that was an issue from day one. The burner was low fire, disastrous and unrepeatable when cycled, and created uneven fires from the three nozzles that would not hold a tune-up. The nozzles constantly needed cleaning and adjusting. Only one person in the boiler room could keep it running for more than a week. They went with a proven installer who recommended a solution that holds a tune-up and remains stable with cycle repeatability in the lower firing ranges.

A medium sized Christian College in Providence RI was interested in going far beyond EPA requirements in order to reduce their emissions and maintain their electrical and combustion efficiency. They selected a solution to achieve the best of both worlds: 22pm NOx on two 900 HP burners with natural gas and #2 oil, with Burnermate Universal controls on both burners/boilers.

A very small private college in central MA was provided a 600 HP burner for an old boiler that was previously fired by a burner from a company that went out of business a few years ago. They also selected the Burnermate Universal controls. Before this, they had been shut down for a few years and faced an unreliable boiler plant. They chose the fuels that were readily available and may consider other options as they continue to invest in infrastructure.

VA Medical Center Case Study

VA Medical Center, Erie, Pennsylvania – Generally, systems that have been in service for 25 to 30 years would require replacement instead of an upgrade. Their system had been in place for three decades and required complete replacement. In order to make the most impact with this important project, they built an entirely new boiler plant from the ground up.

The engineering team at the V.A. determined that existing system had met its lifespan, and they wanted to replace with latest technology. Any short-term replacement would have simply been a Band-Aid. They realized, however, that a project of this magnitude would take time to do properly. The engineering team at the V.A. chose Greenland Enterprises, Inc. to handle the entire project based on their central plant expertise and track-record at other healthcare facilities.

Based on the campus steam load, they determined that the replacement equipment would consist of two 400-horsepower boilers and one 200-horsepower boiler. Installation of the new boiler system took four months. From the ground up (including the new construction), the work on the project took 14 months to complete.

This new plant will provide at least a 60 percent reduction in electricity consumption, which will be accomplished using a variable frequency drive. This technology can run with fan speed at a lower rate. For example, changing the power from 60hz to 30hz speed can cut the horsepower by eight times. Therefore, a 400-horsepower system would be cut to 60-horsepower. According to Steve Seckler, Vice President of Operations at Greenland Enterprises, “Most systems can go from 60hz to 40hz easily. We chose a system that can efficiently go all the way from 60hz to 15hz for additional savings.”

Fuel reduction provides cost savings over the life of the new system. Newer boiler systems can offer a savings of two to five percent. This means that one 400-horsepower boiler with a fuel cost of $500,000 annually can save between $10,000 and $25,000 a year. This new Erie plant, with its two 400-horsepower boilers and one 200-horsepower boiler, will save the hospital between $25,000 and $62,500 in fuel costs annually.

Is it time for an upgrade at your facility?

A boiler upgrade project like the one undertaken at the V.A. Erie Medical Center is clearly something that takes significant time and money to complete. But in the end, management determined that the expense and effort will pay off in the long run. Could it be time for you to look at a similar project for your facility? Here are some points to consider when making your decision.

Sustainability

In large facilities, sustainability can be neglected when considering boiler systems. Facilities like college campuses often rely on older boilers and choose the “Band-Aid” approach of patching and maintaining them out of necessity. This method is not sustainable. Upgrading to a new boiler is the best option for long-term, sustainable improvement.

Sustainability also refers to the environmental impact of a system. With ever-changing state requirements, it is important to choose a system with enough flexibility to face these new demands as well as future ones.

Fuel-efficiency

To sufficiently meet the heating and energy load demands of healthcare facilities, old boilers burn an inordinate amount of fuel. New boilers bring added efficiency and substantial fuel savings. There is also much being done in the realm of alternative fuels for boiler systems. Bio-fuels and liquid wood are two segments of the alternative fuel market that are making great strides.

Operation and Maintenance

New boilers are streamlined to operate more smoothly and efficiently than old boilers, which can be challenging to operate and maintain. The older boilers often take much longer to heat up, and they are often kept running to meet heating needs. New boilers are designed to heat up quickly and can be adjusted to handle variable loads to ensure less energy consumption.

When considering an upgrade or replacement, no matter what the reason may be, all factors of the operation need to be addressed in preparation for a system shut-down. A project of this magnitude, from the initial bid process to completion, will require a minimum of several months (for an upgrade) up to a year or more (for a complete boiler replacement). The impact of this change, and thus the importance of the decisions made during the process, are why so many campuses are carefully reviewing their future energy options.

David Bohn is President and CEO at Preferred Utilities Manufacturing Corporation, an engineering-based manufacturer of products for commercial, institutional, industrial and nuclear power facilities.

 
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Given today’s skilled workforce shortage, figuring out how to get the most productivity from the fewest workers has become one of a power sector’s top challenges. How can a plant stay on top of its output requirements when finding and retaining qualified workers is so difficult?

With spare man-hours being a luxury few can afford, two questions are at the top of most plant managers’ minds:

1. How can we avoid downtime?

2. Are we maximizing our workers’ time and capability?

Following are stories of two facilities that found the expertise they needed to address those issues with innovative, “outside-the-box” solutions.

Keeping downtime at bay

Downtime has always been a costly and inconvenient burden, and finding the resources to make up for time lost to equipment failure can be nearly impossible. A well-known North American tissue manufacturer found itself with old boiler equipment that was not up to the job and needed to be replaced—but they had to find a solution that wouldn’t cause downtime, which they simply could not afford.

Their old equipment did not reach full heating capacity as required. The boiler was rated for a certain steam output, but the burner couldn’t provide enough heat to make that steam. They had a second boiler, but switching required a start-and-stop process that added up to higher operating costs. Every stop meant purging the boiler with air and adding additional wear-and-tear on the system. The process also meant lost energy and additional man-hours. It was not a sustainable solution.

They needed a more reliable source of heat, along with ability to meet NOx emission requirements with better fuel efficiency and a safer system. If they didn’t get the NOx emissions into compliance, they risked hefty fines from their home state. So what would work?

A combination of a new burner, new fuel piping train, and a new variable frequency drive (vfd) was proposed to address the heating efficiency problem. This combination saved costs by reusing the existing controls (which had just been put in place a few years earlier). They included Preferred Utilities BurnerMate Universal (BMU) parallel positioning controls, a built-in flame safe guard, and a touch-screen user interface.

The company proposing this solution had been servicing the manufacturer for years, so they had the knowledge to not only source the right equipment but also coordinate the entire project. They provided a highly qualified subcontractor who provided a complete turnkey solution, removing the old boiler and completely replacing it, attaching the new burner and gas lines and wiring the controls. They took just 11 days to install all the equipment and get it fully functional. It met NOx emissions standards and achieved higher efficiency and turn-down. The entire project, from initial analysis to completion, took less than eight weeks.

Working with the right consultants in a case like this is particularly important because they must be experienced with a full range of boiler equipment so they can always utilize the one best suited for the application. Without the right expertise they might recommend ill-suited equipment that will be detrimental to plant staff who will need to deal with the repercussions and possible failure in the future. That’s more risked downtime—something that was simply not an option in this application.

The burner installed in this application burned natural gas, achieved a 10-1 turn-down, and reached 30ppm NOx (the previous level was 50ppm). Additionally, the installation included a 40,000 pounds-per-hour steam boiler and a Cleaver Brooks water tube boiler.

Keeping boilers under control

A mammoth steel processing plant was far behind in a boiler upgrade project. They turned to an outside consultant to help them pinpoint the problems in the application and get the project back on track.

This was the largest project of its kind in the United States at the time. The engineer had to guarantee less than 25.65 PPM NOx and less than 48.60 PPM CO. The project also required 85 dBA noise level at three feet. All of these stringent requirements ended up being met.

An added challenged faced by the consultant concerned the type of controls to be implemented in the application. The management of this facility had traditionally been against Human Machine Interface/Operator Interface Terminals (HMI/OIT) and had not allowed them. Given their experience with these types of controls, the consultant’s challenge was to convince the customer that offering an OIT is an advantage.

In the end, this solution was accepted because the consultant offered a BMU. The LCD screen is standard on the BMU and is a back-up that will provide them with the boiler-burner operation should the OIT fail. To assist in the rollout of these new controls, the consultant also offered a two-day on-site training session.

The consultant matched the proper controls to the boilers and fast-tracked the resulting installation. A four-week submittal, proposed to the consulting engineers, got approval for both boilers and burners to proceed with manufacturing and meet the schedule.

The final application included three X-Plus burners on three B&W 60,000 PPH boilers with BMU controls. The control system and VFD was located on a high ambient temperature environment of 139°F and in corrosive atmosphere. All controls, hardware, and VFD were rated for 122°F. NEMA 4X requirement encloses the heat from the temperature rise and will exceed all temperature rating of the electrical components. In order to meet the reliability requirements, the consultant provided a NEMA 4X enclosure with NEMA 4 rated air conditioning system.

In both these applications, timing was critical. They could not allow the boiler system to fail, but they also could not afford a lengthy downtime for upgrades. Overcoming a pre-conceived mindset and looking for creative solutions allowed the facilities to resolve their problems and stay productive. In the end, an outside perspective gave them access to both the knowledge and technology they needed to conserve workforce time and talent.

About the author: David Bohn is President and CEO at Preferred Utilities Manufacturing Corporation, an engineering-based manufacturer of products for commercial, institutional, industrial and nuclear power facilities.

 

A New York City Public School central heating plant and their consulting engineer made the decision to install 3 new low emissions burners with state of the art combustion control systems to meet Local Law 87 initiatives.

Compliant with Local Law 87, no fiber metal mesh heads or air filters required.

For sub 35 PPM NOx, burners maintain low O2 performance without FGR and ability to go to sub 9 PPM NOx with FGR– all without fiber metal mesh heads or air filters!

If dual fuel capabilities are added, they can have a sub 5-minute change over from natural gas to oil firing. Their new controls packages includes: BurnerMate Universal O2 Trim, Draft Indication & Control, Fuel Air Ratio Control, Flu Gas Temperature indication and alarm, Smoke Opacity, Flame Safeguard control, with VFDs.

These burners will reduce electricity consumption by 60% or more and allow for 8:1 turn down on oil firing. O2 ranges from sub 1.5% at 50-100% firing rate, to sub 3.5% 10-40% firing rate. The burners and controls package are made by skilled American tradesmen in our Danbury, CT, UL 508 / IBEW shop, and started up by our combustion field engineers.

Made in the U.S.A. for a Greener, more Sustainable and more Fuel Efficient future for NYC.

 

Made in the U.S.A., this project demonstrated a a sustainable, safe reclamation of waste hydrogen with high efficiency and carbon foot print reduction.

An American based chemical manufacturer decided to make use of their waste hydrogen which significantly reduced their use of fossil fuel for their process steam requirements. But the customer needed the right company to deliver a controls, burner, boiler, fuel handling, blending, and a balance of plant integrated combustion package. They came to Preferred Utilities Manufacturing for a total combustion design solution which included a custom (IBEW / UL 508) PLC flame safe guard system with integrated combustion control, fuel ratio control, boiler water control and balance of plant interface. A 10″ touch screen operator interface with plant wide SCADA communications provides easy process / efficency monitoring and trouble shooting operations.

For single source responsibility, significant energy savings, and unsurpassed combustion engineering expertise, choose Preferred.

 

The PCC-IV loop controller is the next generation of Preferred’s loop controllers AND upgraded technology for the entire industry. The PCC-IV is more flexible, has extensive memory, and not only replaces the Preferred PCC-III, but also can replace the Siemens Moore 352 and 353, obsolete and no longer supported starting October 2017.

Preferred Utilities’s controls are just that- preferred. Consider a case study of a longtime PCC controls customer:

Preferred Utilities has been supporting this facility in New York since 1988 with our PCC II and III loop controllers. This site installed one PCC-IV and is now considering this next generation of upgrade, the PCC-IV, in their plant with four (4) 50kpph boilers, each with steam, gas, and oil flow meters.

In 1988, the facility installed 16 PCC-IIs and 5 control panels, plus field instruments for a burner/controls upgrade. Almost 10 years later in 1997, they updated the system with the purchase and installation of 17 PCC-IIIs. In 2002, they decided to upgrade again and add O2 trim. Satisfied with the Preferred product, they installed 21 of the PCC-III units.

Now, in 2017, the plant installed a PCC-IV in parallel with one of the PCC-III controls to observe the performance and is considering upgrading the rest of the PCC-II and PCC-III controls. With the auto-converting functionality of the PCC-IV, the existing PCC-III programs can be re-used without modification and re-programming.

Preferred Utilities is pleased to offer generations of quality products that age gracefully and come with a pledge of full service support and solutions for upgrades in the future.

PCC-IV Loop Controller Front

PCC-IV Loop Controller internal

 

 

 

A New Jersey paper mill came to Preferred Utilities recently needing a quote for a new burner for their 1961 Preferred Utilities Unit Steam Generator. What is wrong with their existing Preferred burner? Nothing. The plant is being forced to convert from No. 6 heavy fuel oil to natural gas.

Will their next burner last 56+ years? Maybe. It depends on who they buy it from.

Note, Preferred still had the documentation on the existing burner and boiler. But we had to go to 49 year Preferred veteran engineer Ricky Erickson to find it.

This plant needs a Low NOx burner that meets the emissions regulations in New Jersey. Preferred designs and builds burners that can meet the strictest regulations, and provides configurable NOx settings, “future-proofing” them against lower emissions requirements that states may adopt in the coming years.

Built for the environment. Built to last.

 

 

Last summer a facility in Texas spilled 3,500 gallons of diesel fuel intended for one of their emergency generators. The fuel was pushed up through a day tank vent, ran across their parking lot, and into a pond adjacent to their property. The clean-up team recovered about 2,100 gallons of fuel out of the pond, but at a cost of about $300,000.

I was called to the site two weeks after the spill and took these pictures of the pond. It’s amazing how resilient nature can be in Texas. The only damage I could see to the pond was browned grass below the waterline. Now, ten months later, the pond appears to have fully recovered.

 

The generator fueling system for this facility was installed in 2013. From an inspection of the day tanks, all the instrumentation and safety devices met the required NFPA and local fire codes. However, I did not recognize the systems integrator who did the PLC controls. I suspected there was an error in the PLC program exacerbated by a system design that didn’t anticipate something going wrong.

 

The facility owner brought in a couple of sharp corporate engineers to autopsy the existing controls. They found errors in the PLC programming logic. A level sensor failed, showing a low fuel level in the day tank, so the PLC controls energized supply pumps to re-fill the day tank from the main storage tank. With the level sensor stuck, the PLC controls ignored all the other instrumentation indicating the tank was full, continued pumping fuel, and quickly overfilled the tank. The facility engineers thought the system started pumping fuel at about midnight. Facility staff coming on duty at 7 a.m. smelled diesel fuel, noticed the fuel on the ground, and shut off the pumps.

 

At first glance, the control sequences for diesel generator fueling systems are not terribly complicated, so local systems integrators are often hired to provide controls for fueling systems. However, to ensure fuel is always available to mission critical emergency generators, and fuel spills are prevented, the Preferred engineers—who specialize in the design of generator fueling systems—try to anticipate every likely failure mode:

 

–What happens if a level sensor gets stuck?

–What happens if an analog transmitter fails and produces 0 milliamps?

–What should the controls do if a pump fails to prove flow?

–What happens if there is a break in a fuel line, or a tank starts to leak?

–What happens if an operator manually energizes a fuel transfer pump and then goes home?

 

After supplying so many fueling systems over the years, all of these failures will happen. Regardless of a component failure or operator error, fuel spills are still unacceptable, and the generators still need fuel.

 

I did boiler controls for twenty years before learning how to design and commission fuel handling systems. NFPA boiler code dictates all the safety devices and sequences required to operate boilers. As a result, at least three separate devices must fail to run the water out of a boiler, or overpressure a boiler. NFPA code for fueling systems is much less specific. In fact, the fuel system that caused the spill at this facility didn’t violate any NFPA fuel handling codes.

 

In the end, this facility’s Preferred installer and consulting engineer commissioned the new Preferred fuel handling system controls. Commissioning is the process of simulating all the “What happens if…” scenarios described above and verifying the fuel system responds correctly to all imaginable upset conditions.

 

It’s the last thing we do on every fuel handling project.

David Eoff, BSME, MBA

Preferred Utilities, National Sales Manager

 

What happened the last time your house lost power? That email you were writing might have had to wait an extra half an hour, and your refrigerator might have warmed a few degrees. At most, ordinary power outages represent a minor annoyance to the home or office.

The situation is different at the massive data centers of the world. Amazon now sells over 600 items per second, and their systems are designed to accommodate up to 1,000,0000 transactions per second. At this scale, a 20 minute power outage at one of the data centers powering its store could cost Amazon millions of dollars in lost revenue.

To avoid this sort of catastrophe, the world’s big data centers strive to meet the Uptime Institute’s “Tier-Standards,” specifying various levels of guaranteed data processing availability, reliability, and redundancy. Meeting these standards requires avoiding single-points of failure — all components must have redundant backups.

One of the most critical components, of course, is the power supply system: without power, the flow of data grinds to a halt. Although massive data centers pull their power from the public electric grid, they must have redundant systems of backup power ready to go. Stored power in batteries is important, but the real backup system is the diesel generator.

Managing the reliability and redundancy of their generator systems is a significant challenge for data centers. It’s an unfortunate reality that components break and systems fail tests. At many data centers, the fuel system supplying the generator will have components from a legion of vendors, not one of whom will understand (or take responsibility for) the whole system. This can make troubleshooting routine systems failures a nightmare.

Working with a company that provides a fully integrated system is essential – from the fuel tanks and pump systems to the monitoring devices and control systems. Therefore if a problem arises, data centers have a single support call to make. A single source contact will understand how the pieces work together and can quickly solve problems. It’s the difference between working with a parts manufacturer with a few engineers on staff, and an engineering design firm that manufacturer’s the parts.

At Preferred Utilities we specialize in fuel systems—it’s what we do all day, every day—we pride ourselves on designing reliable systems that reduce the need for support calls in the first place. Data center engineering teams are generalists and great at looking at the big picture, so when it comes to fuel systems, they often aren’t able to immerse themselves in the details the way our engineers do. We know the code compliance specs, how to make sure the tank size is correct, and how to optimize virtually any scenario to help data centers at all Tier levels to keep the their fuel, power, and data flowing.

If your company or industry requires this kind of technical expertise, you can reach Preferred Utilities Manufacturing Corporation at (203)-743-6741. We are dedicated to your success. People. Products. Results.

 

Boiler Control RetrofitIn conjunction with Puerto Rico representative M.R. Franceschini Inc., Preferred recently replaced an existing flame safeguard and oxygen trim system with the Preferred BurnerMate Universal (BMU) system on a 500 HP boiler at a pharmaceutical plant outside of San Juan.

In addition to oxygen trim, the BMU is controlling the forced draft fan variable speed drive (VSD), and providing first out annunciation of boiler trips. The BMU was integrated with the existing proprietary feedwater control system and all existing boiler limits.Boiler Control Retrofit with BMU

This steam boiler runs continuously on No. 2 oil, which is expensive in Puerto Rico, so the boiler was tuned for the lowest excess air possible at all firing rates to reduce fuel consumption.

In addition to expensive fuel, Puerto Rico has some of the most expensive electricity rates in the U.S. according to the U.S. Energy Information Administration. Industrial users in Puerto Rico currently pay an average of 14.6 cents/kW-hr compared to the national average of 6.54 cents/kW-hr.

Rate hikes averaging 26%BurnerMate Universal have been announced effective in 2017 for the island. With the new Preferred BMU controller, the forced draft fan VSD speed was kept under 30 Hz from low fire to mid-fire, resulting in electricity savings of over 85% compared to 60 Hz operation.

For more information on the BMU Boiler Control System, click here.

 


How much will you save?
Check out the Preferred Utilities Energy Savings Payback Calculator

Ever tried to justify a retrofit project? Now there’s a better way to crunch the numbers. This app will save you time and money. It analyzes your existing boiler and burner system data and compares it against a proposed modern upgrade, complete with energy savings estimates.

The calculation output in this application is extensive. It includes a fuel analysis, combustion efficiency (existing and projected), fuel consumption, electrical consumption, and C02 credit calculations. Use this tool if you are considering a boiler/burner upgrade.

Used for:

  • Boiler retrofits
  • Burner upgrades
  • Control upgrades
  • Energy auditing

Features:

  • Save your work
  • Recall past projects
  • Print your data
  • Compare Preferred equipment

Energy Saver Payback Tool