Boiler energy-saving renovation?
Thread Content
Everyone, please share your thoughts and where to start. A 10-ton furnace was subjected to energy-saving modifications. Due to the small heating surface area of the boiler itself (i.e., the small area of the water wall), the temperature at the exhaust air outlet was about 400 degrees higher. The manufacturer installed an additional passive boiler after the economizer to preheat the water entering the boiler; this led to increased resistance in the exhaust air flow, forcing the exhaust fan to operate at nearly 100% of its capacity. What approaches can be taken to improve energy efficiency in this situation? What will be the energy-saving efficiency after the renovation? This furnace is designed for 10 tons, but its current output is only 6 tons? Question: How to learn*learning*
1. Which equipment needs to be replaced for the renovation? 2. This furnace is currently under manual control; if it is switched to automatic control, how much can the current condition of the boiler change? 3. Is it necessary to change it to automatic?
A economizer and a low-temperature air preheater are added at the rear of the Kaolv boiler. To avoid increasing wind resistance, the structure of the tail heating surface is arranged reasonably.
Thank you for your reply! Could we talk more about it? To be more specific, there are many types of economizers available these days; which type is the best to use? :D
Usually, energy savings can be achieved by modifying the furnace arch, with only a minor increase in flue gas and air resistance. Is the modification unit used by the original poster a counterfeit one?
Thank you for your reply. Could you help analyze whether my view is correct? There are serious flaws in the configuration and control of this furnace; from the perspective of energy consumption alone, energy is lost through the flue gases. If I burn less coal and reduce the amount of exhaust air as well as the blast air, can I then save energy? Question: Is there anything wrong with my idea? If there is a problem, why? If there are no problems, can it just be changed to automatic control?
The combustion in coal-fired boilers has a certain lag time; automation can only serve a safety purpose and is not very useful for improving boiler efficiency – the key lies with human intervention.
First, determine whether the coal type matches that specified for boiler design. The boiler should be equipped with layered coal hoppers to improve combustion efficiency and reduce ash loss. Pay attention to the boiler’s negative pressure; the excess air coefficient should not be too high. Adjust the proportions of the blower and exhaust fan valves appropriately, as well as change the frequency of startups.
There is a problem with your boiler; the heat loss through exhaust smoke is too high. I’m not sure if this was the case from the start or arose after repairs. Such problems are quite complex, with many possible causes. For example: unreasonable design, incorrect heights, elevation angles, and positions of the furnace arch (front, middle, rear), the arrangement of the heating surfaces, whether scaling occurs, and the airflow distribution, etc. The designed thermal efficiency is around 88%, while the maximum output is about 110% of the designed value (11 T/H).
What boiler? Fuel? I’m interested in helping you solve it!
First of all, what fuel does your boiler use! Coal, gas, oil. Second, where was this boiler manufactured? Is there a thermal calculation available, and what is the area of the heating surfaces? What are the values for radiation and convection respectively! Third, what is the fuel consumption at a power output of six tons? How high is the thermal efficiency? Fourthly, only by identifying all of the above issues can it be determined If the exhaust temperature remains high as the fuel consumption decreases, I suspect there is a flue gas short circuit in the boiler! Boilers produced by regular manufacturers generally do not have such a large difference (40%); a difference of 10–20% is normal! If you’re interested, feel free to contact me; I can analyze it for you. I’ve been in this field for over ten years!