The energy transition towards a zero-emission future is posing important challenges to governments, businesses and citizens. We recently talked about it in the article “The energy of the future”, where we listed the strategies put in place to achieve the goal of decarbonisation [if you missed the article, find it here].
Among these, a major contribution is provided by the improvement of energy efficiency, which, especially in the industrial sector, is fundamental not only to obtain important savings but also to improve the performance of the production system: the modernization of the plants, with the introduction of new, low energy consuming and more modern, intelligent and reliable technologies, brings with it the reduction of costs, both for maintenance and operation, and the reduction of manufacturing waste, decreasing the defects of the product.
But what is energy efficiency? And how this concept can be applied to steam generators?
Energy efficiency is the ability of a system to make the best use of the energy supplied to satisfy a need. If we apply this concept to a steam generator, we can say that energy efficiency is the measure of how much fuel the boiler is able to transform into energy, in the form of steam.
So when I evaluate the purchase or replacement of a boiler, what should I consider?
Boiler efficiency: what are the parameters to control to obtain high efficiency?
The first parameter that must be monitored is the temperature of the flue gases at the chimney: an important index to understand how much heat, and therefore how much energy, is dispersed by the boiler.
The optimum flue gas temperature (which avoids possible condensation problems) is between 80-85°C. In the very common case economizers are used, this value is directly proportional to another parameter, that of the temperature of the water introduced into the boiler (feed water): the hotter will be the water, the hotter will be the fumes (because they will release less heat to the water). For a better energy recovery, it is therefore preferable that the water is as cold as possible.
Finally, another value to monitor is the content of oxygen in the fumes which, to be optimal, must be between 2% and 4% (in this range, the weight on efficiency is 0.2-0.3%). This is because an excessive concentration of oxygen in the fumes is equivalent to discharge more fumes in the environment. Therefore, at the same temperature (85 ° C, for example), the greater is the quantity of fumes, the greater is the energy that is being dispersed.
A possible solution to an excessive presence of oxygen in the fumes is the reduction of excess air in the burner.
Boiler efficiency in my working conditions: nominal value vs real value
We said earlier that energy efficiency is the relationship between what is produced and the energy required to do it. So how is the punctual value of efficiency provided by all manufacturers calculated?
The declared efficiency level is calculated on the basis of particular conditions, we could say of “laboratory conditions”, which however hardly correspond to real working ones.
In fact, this value would be actual or real if the boiler always worked at maximum power, without changes in load or in external temperature or in the feed water. But the daily operation of a steam generator does not have a stable trend: the changes in load and the (physiological) change of the boundary conditions impact the performance of the boiler, which in this way can lose several points of efficiency.
However, there are solutions that can reduce the effects of this variability: the patented HE Smart system guarantees very high levels of efficiency in any condition of pressure, load and water temperature, ensuring the stability of the flue gas outlet temperature. As you can see here below, He Smart guarantees the highest levels of efficiency also with load variation.
Beyond the boiler: interconnection with the production system
Widening the vision from the single boiler to the entire boiler system + production plant (the connection between the object that generates steam and the user that consumes it), it is possible to find additional profit margins in terms of efficiency.
Interconnecting the boiler with the entire factory means collecting, through a large network of sensors, a series of data related to process that specific software stores on the cloud, processes and uses to automatically monitor and report no-optimal progress, thus giving the possibility to continuously optimize boiler operation.
These data, giving an overall view of the performance of the entire process, allow also to monitor consumptions and to develop mathematical models used by modern control and management systems to operate the boiler in an adaptive way, optimizing the loads and consumptions according to the uses.
Why it is so important improving the energy efficiency of the boiler and of the plant in which it is installed?
Maximizing the efficiency of the boiler, in addition to improving the performance of the production system, allows to minimize the waste of energy, and at the same time, to reduce the operating (and maintenance) costs of a steam generator.
Again, widening the vision of the costs related to the steam generator over its entire lifetime, it is evident that the initial investment represents a small percentage of the boiler overall cost. The main part (estimated around 70%) consists of the amount spent to power the boiler itself; in other words: gas bills. Finally, another important part of the overall cost is that related to maintenance (about 10%).
Improving the efficiency of the plant in which the boiler is installed means significantly reducing these costs and, consequently, obtaining huge savings.
If you want to know more about how Cannon Bono Energia steam generators can help you saving, fill out the form below and request more information.
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