Thanks in large part to their sturdy pressure vessels, boilers can often operate reliably for decades. This means that even large, well-respected facilities can have antiquated and inefficient burners and controls. With recent advances in technology, there are now many ways to reduce the operating costs of boiler plants without resorting to the expense of replacing entire systems. Even if you are committed to improving efficiency in your heating plant, it’s difficult to justify spending millions of dollars on completely new boilers.
"Boiler systems that can communicate higher-order technical information not only help facilities managers stay ahead of problems but also empower them to analyze fuel usage trends and heating efficiency. The best remote monitoring tools can be set to optimize the facility’s carbon footprint."
Retrofitting Controls on Existing Burners
Many types of facilities with a long lifespan have aging burners on their boilers. They are still reliable, but they operate inefficiently. These burners typically use a technology called “jackshaft linkages” to mechanically control the burner fuel-air ratio. Recent innovations have reduced the cost and made it easier to retrofit upgraded digital controls on such existing burners.
The mechanical nature of jackshaft linkages presents complications in configuration and maintenance. Even though the service manual may list admirable performance specs for burner turndown, efficiency, and emissions, it is difficult to achieve those numbers with mechanical linkage. Highly skilled technicians are needed for adjustments, and those adjustments are still error prone. This all means that the norm is to adjust the burner only for reliable operation, but not for efficient operation.
Even if adjusted for peak efficiency initially, the mechanical shafts, lever arms, and linkages have many wear points. This makes it more likely that the efficiency will slip over time, using more fuel and electricity and producing more emissions.
With both electrical and fuel prices on the rise, replacing jackshaft linkage with a “linkageless parallel positioning system” could be the ideal compromise. Parallel positioning systems digitally adjust the ratios of air and fuel delivered for optimum combustion. They are set separately for each fuel fired. Parallel positioning system costs start as low as $5,000.
Independent, multi-year studies have documented many ways in which operating costs are reduced by linkageless controls.
• Digital fuel-air ratio curves more closely, and more repeatably run the burner at peak efficiency at all firing rates.
• Digital controls can interface to an FD fan VSD for large electrical cost savings, while jackshaft controls can’t.
• Digital controls can interface to flue gas oxygen sensors for year-round automatic peak fuel efficiency, while jackshaft can’t.
• Lower off-cycle heat loss is reduced because linkageless fully closes the air damper when not firing. Jack-shaft keeps the air damper open at the low fire position when not firing.
• Reduced on-off cycling reduced purge and startup losses due to wider turndown for dual fuel gas-oil burners.
• Electronic pressure/temperature sensors with digital firing rate control reduced burner on-off cycling due to jackshaft electro mechanical firing rate controllers.
Remote Monitoring: Boiler Controls and Data in Your Pocket
If you study a typical hospital’s backup power generator, you’ll notice a lot of wires running out of it and into the walls. If you follow their twisted path through the walls and ceilings, you’ll run into other bunches of wires from other generators. Follow the path long enough — which won’t be easy — and you’ll end up in the hospital basement at a pump system that’s responsible for getting fuel oil from a fuel tank up to the generators.
Imagine an operator walking from generator to generator, and building to building, to check system consoles for errors. This takes hours, and if a system failure is found, the source will have to be tracked down. In a typical installation, there might be more than 120 wires connecting the generators to the pump system. It’s not an easy situation to troubleshoot.
As “the Internet of Things” becomes the norm, these problems are being solved with remote monitoring of heating equipment. Who wouldn’t want to access a complete record of data along with instant notifications of issues right on their smartphone?
Naturally, remotely monitored boiler systems have an edge in emergency situations because they send alerts in real time. For mission critical facilities such as data centers and hospitals, round-the-clock maintenance staff for facilities containing heating and cooling units is a major expense. Remote monitoring makes on-call staff just as effective. Additionally, remote monitoring frees up staff members to attend to other tasks while remaining readily available to respond to malfunctions or failures of any boiler system.
Real-time alerts allow most issues to be solved before they have a noticeable effect on the temperature of the building. This is critical on hot or cold days when the temperature inside can change quickly. In some cases, the problem can actually be fixed remotely. For residential and office facilities, issues can arise and be dealt with without tenants noticing — a sharp contrast to the typical situation of learning of issues on the phone with upset tenants.
Know Your System Like Never Before
In addition to shortening reaction times, remote monitoring can enable the collection of useful data. The determining factor here is the age of the controller and how much data it can report. Older controllers may be able to tell only when a boiler is running properly and when one shuts down unintentionally. On the other hand, newer controllers can communicate why a boiler shut down, how much fuel it was using, what the heating demand is for the building each day, how efficiently the boilers were running, whether they were firing natural gas or backup oil, and more. This information can be used to diagnose potential problems and inefficiencies.
Plus, this information adds up over time so trends can be observed. Facilities managers no longer have to log issues by hand or rely on memory to tell them when the last time a similar issue occurred. By effortlessly providing detailed tracking, informed decision making becomes easier.
Boiler systems that can communicate higher order technical information not only help facilities managers stay ahead of problems, but also empower them to analyze fuel usage trends and heating efficiency. The best remote monitoring tools can be set to optimize the facility’s carbon footprint and reduce operating expenses by cutting fuel and electricity usage.
If It Ain’t Broke, It May Still Be Time for an Upgrade
It’s easy to fall into a pattern of replacing what breaks, but in truth, boilers rarely break. It is worth considering what an upgrade could mean to efficiency whether or not something needs fixing right now.
The last few years have seen major innovations in boiler technology. If they’re not paying close attention to the industry, it would be easy for facilities managers to miss opportunities to contribute to strategic climate initiatives, help balance the budget, and deliver greater reliability.
Don’t Neglect System Design
As we’ve discussed, improvements like upgrading the boiler controllers can improve the sustainability of a boiler system; however, a boiler system consists of many more components. Tanks, regulators, pumps, and other components can all affect efficiency and sustainability. It is necessary to think of the system as a whole to truly create long-lasting improvement.
With this in mind, you should look for the best approach for your facility — and that might not mean simply seeking out a parts manufacturer to provide individual components. You can choose to partner with an engineering firm that also manufactures parts in order to get system design advice from the start of your project. This type of firm can look at your overall operation and determine which components might be upgraded and what other changes might be recommended to maximize the value of the upgrade. In the end, making the right changes to your system all at once can help you reach your goal of top efficiency and long-lasting improvement for your investment.