8 keys to improving boiler efficiency

Improving boiler efficiency is key to an organisation's ability to reduce operating costs. In fact, reducing consumption and reducing costs will always be the first objective and the boiler has a big part to play in achieving this.

Think about it; the boiler draws in cold air, heats it up and sends it out of the chimney. A lower flue gas temperature is ideal because the higher the temperature, the more energy goes out with the flue gas. On the other hand, the boiler system takes cold water, heats it to steam and uses the heat. Wherever we lose heat, steam, condensate or hot water, we lose valuable BTUs.

Whether you own or rent a boiler, you need to save money, so here are 8 tips we know how to improve the efficiency of your boiler and save money on your monthly bills:

1. Clean the water side

   Keeping the water edge of your boiler clean and free of leaks requires diligent water treatment. Inspect the water edge of your boiler regularly. Clean the mud legs or mud drums to ensure good heat transfer from the metal to the water. Scale will build up on heat transfer surfaces due to high water hardness, improper chemicals and lack of air from the boiler on a regular basis.

   This scale will impede heat transfer, reducing the efficiency of your boiler. Scale will also prevent water from cooling these heat transfer surfaces. If left untreated, scale can cause the boiler to overheat, leading to costly boiler repairs and leaks.

2. Return condensate to the boiler

   Condensate is formed when steam transfers its heat and condenses. It is irresponsible to waste this by-product. Clean water is free of dissolved solids and gases that are ready for use back in your boiler. The water is already hot and therefore requires much less fuel to turn it back into steam.

   The reuse of condensate also reduces the amount of cold make-up water., The chemicals and treatment that is required for your boiler. Finally, redirecting condensate back into the feedwater system can reduce wastewater treatment and sewerage costs.

   For an even greater increase of the boiler efficiency, consider a high pressure condensate return system in its largest steam users. This keeps your condensate at a higher pressure. The condensate does not flash, so it returns more water at a significantly higher temperature directly to your boiler.

3. Recovers heat from boiler play

   Like returning condensate to the boiler, recovering heat from the boiler blowdown can improve boiler efficiency. The blowdown valve is used to remove boiler water containing soluble and insoluble solids. It helps to reduce the level of dissolved solids in the boiler water to prevent boiler scaling.

   Unfortunately, when you remove hot water, you also waste energy. The installation of a purge heat exchanger, A flash tank or a combination of the two can help recover some of this energy for your boiler system. Using heat recovery to cool the blowdown and heat make-up water will improve energy efficiency.

4. Purge rate control

   Flushing removes impurities, such as hard water, from the boiler and is necessary to keep the boiler surfaces clean. However, blowdown also removes heat from the system. Water enters the system cold, is heated to the boiler temperature and exits by 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 to only the amount necessary to control dissolved solids. For significant savings, control dissolved solids with an automatic blowdown valve. If you shut down the boiler regularly, it can save a lot of energy. This also reduces the risk of damage to your boiler from the scale.

5. Reduce excess air

   Boilers require excess air to complete combustion. Although necessary, the amount of excess air can result in totally different efficiencies for your boiler. Too little excess air and the boiler will build up soot and dangerous carbon monoxide, while too much excess air reduces efficiency.

   Fortunately, there are automatic combustion control systems that can intelligently monitor the amounts of air needed for your combustion systems. As previously mentioned in the article 7 steps to increase boiler efficiency, Tuning can keep your burner operating at peak performance, but is limited to the best that your previous burner can offer. Upgrading to a high efficiency burner will save a significant amount of fuel and will pay for itself many times over.

6. Reducing drag

   Carry-over is the boiler water that leaves the boiler in the steam, but is still water. It carries with it impurities such as dissolved solids. These impurities leave deposits around the steam system. They get trapped inside intricate devices such as control valves and pressure regulators. This causes a lot of damage and increased maintenance.

   In terms of efficiency, this moisture reduces the BTU content of the steam at 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. Carryover occurs due to a number of things. The solution depends on the cause. Suspect operating practices such as carrying loads with high and fast TDS or poor separation equipment as the culprit.

7. Inspection of vapour traps

   Clogged, worn or simply broken steam traps can remain open, allowing valuable steam to pass directly into the condensate system. If you want to ensure that it is operating at maximum efficiency, inspect your steam traps regularly and replace broken or stuck traps.

8. Reduce the use of steam

   The best way to save fuel and electricity in your boiler is to reduce the use of steam in your processes. Insulation of steam-heated pipes and tanks, for example, can significantly reduce steam use and therefore fuel use. High pressure condensate systems can reduce steam use in your deaerator and fuel use in the boiler.

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