Industrial Steam Efficiency – Think Really Hot Compressed Air

Posted by Dalkia Solutions on May 26, 2015 2:38:55 AM

Steam has long been an efficient way for manufacturing plants to deliver predictable, even heating to their production lines.  Typically our customers use medium pressure steam in food processing, as an input for metal or rubber manufacturing or to purify vapor streams in the production of chemicals.

Recently our industrial team modeled an energy efficient steam upgrade at a customer’s plant and the investment math seemed too good to be true.

Our scope involved touching all aspects of the system, including updating the boilers, insulating and repiping steam loops, repairing leaking steam traps and reducing demand at the process end-points.  However, our engineers knew that “comprehensive” could translate to expensive, as their approach required significant engineering and implementation labor, metering, boiler controls and valving, rerouting and insulation for the piping network.

But when all of our costs were considered, along with an offset from a modest utility incentive, the simple payback on pure energy savings was 10 months.

It was a stark reminder of just how much wasted output really costs a plant when operating an on-site, 24 x 7 x 365 thermal energy production system.  An inefficient overall design, deteriorating components and normal decay within an overworked system all add up.

And just as we see with plant-wide energy efficient compressed air, the investment math for fixing these system deficiencies is attractive – only even better.  Efficiently producing and distributing networked steam and compressed air while limiting overproduction has big payback. With compressed air you save electricity (the motor driving the compressor.)  But with steam you save electricity (motors for pumps and fans) and fuel for the boiler.  Steam costs a lot more than air.

Of course, the low hanging fruit in plant steam will always be steam trap repair, a maintenance routine that every plant should implement.  This basic upkeep technique has fast financial payback with local vendors who can perform this function.  Simple software tools from the DOE allow plant managers to model the energy savings from steam trap repair proving their maintenance has clear financial payback.

More complex, but with more significant $ savings upside, are steam system upgrades that address overall design, boiler performance, system components, the network and reductions at the endpoints.  Applying the latest controls at the boiler, valves and end-use points can be very effective additions to older systems, all while giving monitoring visibility.

But applying the newest technologies is only a part of the story.

Our engineering team always starts by partnering with the plant’s own operations team.

These are the experts who know best where steam production trumps efficiency (“turn it up, we need production!”), where the weak points are and where old equipment desperately needs to be fixed.  Our team focuses on proving that the payback for upgrading the steam system is stunningly fast and getting the upgrade money (i.e. convincing their management to approve our budget.)   And during our implementation we work hand in hand with our operations partners to minimize any disruptions to production.

While we think our industrial energy efficiency team has special skills, plant upgrades can only be accomplished with this level of collaboration with our customer’s team.   Ultimately we make a trade – our team promises to get the money and perform the upgrade – and their operating team promises to maintain the system in this new, optimized state.

And this makes everyone confident that next year the new steam energy savings won’t just evaporate.

Topics: Steam