Three important considerations pertain to fuels, emissions, and efficiency. All three have important impact on boiler performance, and can affect long-term boiler operating costs.
Remember, from an operating perspective, fuel costs typically account for approximately 10% of a facility's total operating budget. Therefore, fuel is an important consideration. Normally, the fuels of choice are natural gas, propane, or light oil. Increasingly stringent emission standards have greatly reduced the use of heavy oil and solid fuels such as coal and wood. Of the fossil fuels, natural gas burns cleanest and leaves less residue; therefore less maintenance is required.
It can be advantageous to supply a boiler with a combination burner that can burn two fuels independently - for example, oil or natural gas. A combination burner allows the customer to take advantage of "peak time" rates, which substantially reduces the costs of a therm of gas when operating "off peak" by merely switching to the back up fuel. Dual fuel capability also is beneficial if the primary fuel supply must be shut down for safety or maintenance reasons.
Some waste streams can be used as fuel in the boiler. In addition to reducing fuel costs, firing an alternate fuel in a boiler can greatly reduce disposal costs. Waste streams are typically used in combination with standard fuels to ensure safe operation and to provide additional operating flexibility.
Emission standards for boilers have become very stringent in many areas, because of the new clean air regulations. The ability of the boiler to meet emission regulations depends on the type of boiler and burner options. |
