When it comes to specifying a boiler system, one size does not fit all. There are several types of commercial and industrial boilers available, and many are designed to perform a distinct function or supply specific processes. It’s not that using one type of boiler system over another may be wrong for an application, but you may experience a less-efficient operation by misapplying the technology. Here are some categories of boilers, with an explanation of their uses in residential, commercial, and industrial applications.
Hot Water / Building Heat Units – Commercial and residential boiler systems supply hot water, building heat, or both to office complexes, apartment buildings, and similar structures. “Heat Only” boilers do just that, supply only heat to a building, and as a result are usually compact. “Hot Water Units” require a separate storage tank and piping distribution system to deliver a constant supply of water to a facility, and are designed such that multiple users can pull from the system simultaneously.
Combination Units – Combination units supply both hot water and heat to a building, but are slightly different than Hot Water units in that hot water is supplied instantaneously on an as-needed basis instead of being stored in a tank. These units have the advantage of being more energy efficient because fuel is not wasted heating water that will sit in a tank, but have the disadvantage of being limited to the water supply line capacity, usually only a couple of users at a time.
Condenser Units – Condenser units are boiler systems that capture and re-use the steam condensate after most of the usable energy has been extracted. These types of industrial boilers usually include a turbine-generator with the condenser located after the low-pressure stage. Condenser units are very efficient because the condensate they reuse contains some residual heat that offsets the fuel requirements. The condensate is also treated, which saves money in terms of chemical addition cost over raw feedwater. A condensing boiler system has an efficiency that typically exceeds 90 percent.
Cogeneration Units – Cogeneration [also known as Cogen or Combined-Heat-and-Power (CHP)] boiler systems are common in both utility and industrial settings, and are so named because they supply two different sources of energy from a common fuel, usually electricity and process steam. In industrial plants, steam drives a turbine to produce electricity, and the extracted steam is used to heat processes within the facility. Utility cogen boiler systems also use steam to drive a turbine, but the extracted steam is used to heat a town, community, or district.
Heat Recovery Units – Heat recovery boiler systems (also called Heat Recovery Steam Generators, or HRSGs), are installed to capture heat that would otherwise be wasted from an industrial or utility process. HRSGs are commonly found on the outlets of gas turbines, smelting plants, or blast furnaces, where heat is required to perform the process, but not necessarily needed for any other purpose. HRSGs are installed to cool the flue gasses from these processes prior to discharge, and have the added benefit of generating steam to be used for other facility processes or for district heating. Heat recovery units are common in cogeneration plants where heat that would otherwise be wasted after steam generation is recovered to provide lower pressure steam for additional facility heating or feedwater and combustion air preheating.
Refuse Boilers – Refuse (or waste) boiler systems generate energy from a waste stream such as used tires, biomass, sludge, or residential trash. They serve the dual purpose of reducing the final volume of refuse that finds its way to landfill and producing steam for other processes. They operate in a method similar to other types of industrial boilers, the main difference being the fuel source.
This is only a sampling of the many different types of boiler systems available. By combining the right boiler technology with the desired outcomes, almost any application can be properly designed, installed, and operated. Starting with a knowledgeable boiler expert is the key to ending up with a system that meets your needs. The engineering teams at Victory Energy are experts in boiler design and technology.