Steam is regularly used in industry for heating or as a driving force for mechanical power, but breaking down the steam system can be overwhelming; from steam traps to boilers, distribution to generation, there are so many components of establishing an energy-efficient steam system that it can be hard to know exactly where to start. To help you sort through the technical jargon, we’re bringing you the basics about how to create (and maintain) an energy-efficient steam system.
Generation, distribution, end-use and recovery
According to the U.S. Department of Energy, there are various components of steam systems, including steam generation, distribution, end-use and recovery. The purpose of steam generation systems, which are typically classified into either fired boiler or waste heat systems, is to produce the steam required for the system’s end-use requirements. Steam distribution systems are designed to link the output of the steam generation system to the steam end-use equipment by supplying steam at the desired rate and pressure, with minimum heat loss. Sources like the Office of Energy Efficiency at Natural Resources Canada suggest that distribution heat losses can account for 5-15% of total energy generated in a boiler system; that’s a lot of energy, and money, down the tube that can be prevented by proper maintenance and upkeep.
The steam end-use system, as you might have guessed, optimizes the use and heat content of the steam transmitted throughout the distribution process to the end-use equipment. Steam recovery systems make the most effective use of all remaining steam and condensate energy at the end of the process. These systems output condensate that is returned into the generation system in order to save business on energy and energy-related costs.
What is a steam trap?
When we talk about steam systems, we also talk about steam traps. According to Armstrong International , in order to guarantee overall efficiency, the job of a steam trap is to provide minimal steam loss, and air and CO2 venting, while being resistant to corrosion and operating against back pressure.
Steam traps are automatic valves that can tell the difference between steam and condensate, and other fluids. Designed to ensure that steam is not being wasted, steam traps get rid of the condensate that builds up because of heat loss through the piping. Wasting less energy means burning less fuel which, in turns, means reduced emissions, and lower energy costs for your business.
5 Tips for maintaining an energy-efficient steam system
While there are a number of things you can do to maintain and operate an efficient steam system, here are a few tips to get you on your way to energy savings, fast!
- Leaks: Monitor blowdown and feedwater to detect leaks and make necessary repairs. Installing flow monitors can also help monitor leaks if your system is large enough to accommodate them.
- Insulation: Did you know that adding even one inch of additional insulation to existing pipes can reduce heat loss by up to 90%? Check to see if older insulation is damaged or was removed during maintenance to valve and fittings, and take necessary measures to repair. If you’re interested in determining how much insulation is necessary to improve the efficiency of your steam system, check out this free software, developed by the North American Insulation Manufacturers Association.
- Piping: How old is your boiler? Since boilers have a tendency to last a long (long long) time, they can survive multiple check-ups an undergo maintenance that can result in redundant, unused piping. If you have extra piping – take it out! Also, be sure to double-check if your piping is the right size. If the diameter of the pipes is too small for the flow rate, the pressure drop may result in too low a flow rate for the end use. Finally, make sure that distribution piping is adequately supported, guided and anchored with room for future growth.
- Steam Traps: Check and repair your steam traps! These bad boys have a fail rate of around 25% per year, meaning that good maintenance is required on a monthly basis at least. Also, make sure that your steam traps are the right size: too small and you could wind up with condensate backup and excessive cycling, too big and lots of steam can be lost if something goes wrong.
- Excess air: Get rid of it! Measuring your fuel flow and air flow, will help increase your steam generation efficiency and save on unnecessary costs. Keep in mind that the boiler efficiency can be increased by 1% for each 15% reduction in excess air or 40 degree (Fahrenheit) reduction in stack gas temperature.
Financial aid for steam system efficiency
If you’re a commercial or industrial business looking for financial aid, educational seminars and technical support when it comes to implementing an energy-efficient steam system, check out the Steam Saver Program, supported by Enbridge Gas Distribution and promoted through the Office of Energy Efficiency.
You can also check out this Steam System Calculator made available via the Advanced Manufacturing Office of the DoE and these rebates and incentives, offered to businesses investing in energy-efficient equipment! You can also try this FREE energy audit to see how your industrial business can save even more on energy costs.
Questions or comments about your steam system? Leave them below!
image credit: Adam Cohen