Running your boiler at optimum efficiency is getting crucial with the increasing cost of fuel . However, before we talk about getting our boiler energy efficient, let’s find out how a boiler operates. As we know, the boiler takes in the cold air or the cold water and then heats it up to steam. But what happens to the residue heat? If it releases through the stack and increases the stack temperature, that’s where you are having fuel wastage.
But in modern, condensing boilers, that extra heat gets used for heating and hot water supply, thereby making it more energy efficient.
However, if you are finding ways to increase your boiler energy efficiency, there are a few tips that have been explained below:
1. Check the Stack temperature: If you are using a boiler with a high stack temperature, that mainly indicates wasted fuel and poor energy efficiency. As you reduce the stack temperature, it also reduces the return temperature, thereby saving you energy and money. So to get your boiler to run more efficiently, your stack temperature should be lowered almost close to the temperature surrounding the boiler.
2. Get an Economizer: Installing an Economizer can help the boiler in capturing the heat that normally gets wasted through the flue. This exhaust hot flue gas normally has a high temperature of 200°C – 250°C and is used to heat the feed water by the economizer. This is a heat recovery device and normally plays a great role in increasing the overall boiler energy efficiency.
3. Fit a Variable Frequency Drive: Instead of a damper or a valve, it’s better to fit a Variable Frequency Drive to the boiler fan or the circulation pump. This is a device, which can control the motor in a much better way. It can determine the load intensity and make the motor run accordingly, thereby increasing its boiler efficiency.
4. Keep the Valves and Pipes Well Insulated: Just as you do with your pipes, you also need to keep your valves well insulated. That will not only prevent heat loss but will also keep them working properly at their desired temperature.Otherwise, this releasing heat will not only waste fuel but also get the surrounding temperature to go too hot, even causing burns and damage.
5. Clean the Waterside and Fireside: As your boiler provides heating and hot water, both it’s waterside and fireside gets unclean with the contaminants. Cleaning the soot from the fireside and the mud legs from the waterside can help better heat transfer from the metal to the surrounding air or water. However, if kept unclean, the hindrances formed by these deposits will not allow the heat to be utilized fully, instead a part of it will be released through the flue.
6. Reuse the Condensate: One of the best ways to increase boiler efficiency is to get more condensate returned to the boiler. Heat is transferred to steam which returns in liquid form as the condensate. And the condensate being free of any dissolved impurities requires less blowdown which saves good energy. Moreover, as it is already hot, it requires less fuel to convert it into steam.
7. Install Blowdown Heat Exchangers: To get your boilers to function properly, dissolved minerals and salt present in the boiler water should be removed using a blow-down valve. But this process is found to have considerable heat loss. So a blowdown heat exchanger and a flash tank are better used to recover that energy.
8. Get Rid of Excess Air in your Boiler: Excess air, going too low in boilers, can result in incomplete combustion. Now as the combustibles remain partly burnt, they can give out soot, smoke, and even poisonous carbon monoxide gas. But, on the other hand, if the excess air goes too high, it increases the flue gas flow and therefore lowers the boiler efficiency. However, to monitor the correct air quantities in the system, you can better fit in an automatic combustion control system in the feed line of the boiler.
9. Prevent Boiler CarryOver: While the exhaust gas leaves the boiler fuel, there are other things like liquid, gas, and solid contaminants, that also go out of the flue. Carryover is those things that are also found to form deposits in valves, heat exchangers, turbines, and superheaters. If ignored, with time it can hamper the boiler’s efficiency to a great extent emergency plumbers