1. Tune the Burner Regularly
For proper combustion of fuel inside the boiler, a certain amount of oxygen is required. If too little air is present, the carbon in the fuel will be oxidized, making carbon monoxide. This causes less heat to release because the fuel isn’t completely burned, which lowers fuel use efficiency. Low air generates soot, smoke and carbon monoxide, all of which are very dangerous. Too much air also reduces efficiency. The extra air comes in cold and sent out the stack hot, wasting heat. An optimal process provides just enough air for the fuel to burn safely.
2. Clean the Fireside
Sooting, fouling, clinkering and other combustion deposits are common fireside occurrences in boilers and thermic fluid heaters. The adhesive properties of un-burnt carbon results in the formation of incombustible solids on the heat transfer surfaces, resulting in poor heat transfer, reduced overall boiler efficiency, and increased fuel consumption. Cleaning the fireside will help keep your boiler performing at its optimal performance.
3. Clean the Waterside
Low and medium pressure boilers must be protected from scale deposition and corrosion to promote optimum energy efficiency and to prolong the useful life of the boiler system equipment. Implementing a well-controlled boiler water treatment program will create significant reductions in fuel costs, water usage, and environmental emissions. Inspect your boiler‘s waterside regularly. For example, scale will accumulate on heat transfer surfaces because of high water hardness, improper chemicals, and not blowing down the boiler regularly. This scale will impede the heat transfer, reducing your boiler efficiency. The scale will also keep the water from cooling these heat transfer surfaces. If left untreated, the scale can cause the boiler to overheat, leading to costly boiler repairs and leaks.
4. Return Condensate to the Boiler
Condensate forms as the steam transfers its heat and condenses. It is irresponsible to waste this by product. The clean water is without dissolved solids or gasses that are ready for use again in your boiler. The water is already hot and therefore requires significantly less fuel to make it into steam again. Reusing the condensate also reduces how much cold makeup water, chemicals, and treatment is required for your boiler. Lastly rerouting condensate back into the feed water system can reduce wastewater treatment and sewer costs.
5. Recover Heat from Boiler Blowdown
Much like the return of condensate to the boiler, recovering the heat from the boiler blowdown can increase boiler efficiency. The blowdown valve is used to remove boiler water which contains soluble and insoluble solids. It helps reduce the level of dissolved solids in the boiler water to prevent the boiler scale. Unfortunately, when it removes hot water, it also wastes energy. Installing a blowdown heat exchanger, flash tank or combination of the two can help recover some of this energy for your boiler system. Using heat recovery to cool down the blowdown and heat up your make-up water will improve energy efficiency.
6. Control Blowdown Rate
Blowdown removes impurities, like water hardness, from the boiler and is required to keep the boiler surfaces clean. However, blowdown also removes heat from the system. Water enters the system cold, is heated up to the boiler temperature, and leaves through the blowdown. Some boiler systems have continuous blowdown that does not change with boiler load. To control the heat sent down the drain, blowdown should be limited only to the amount necessary to control the dissolved solids. For serious reductions in blowdown rate, implement an improved water treatment program to control dissolved solids and hardness present in the water utilized for your boiler system.
7. Reduce Carry-Over
Carry-over is boiler water that leaves the boiler in the steam but is still water. It carries impurities such as dissolved solids with it. These impurities leave deposits around the steam system. They get caught inside intricate devices like control valves and pressure regulators. This causes a lot of damage and increased maintenance. As for efficiency, this moisture reduces the BTU content of the steam at the end-use. Essentially, this is more water that was heated in the boiler but did not give off useful heat before going to the condensate system. Carry-over happens because of suspect operating practices such as bringing loads on fast, high TDS in your water, or poor separation equipment as a culprit.
Consider taking these steps if you have boiler efficiency concerns or to ensure your boiler continues to operate at its peak performance!