MAEC
Mechanical
- Feb 21, 2006
- 11
Hello members.
A few months ago I came to this forum asking for tips on energy balances and exergy analysis for a sugar industry project. Since the begining of the project, which lasted 26 months, I often came here for replies on such inquiry but just a few were given. Now I am back to let those that were interested in its moment that the project was succesfully finished and amazing results were obtained, results I will briefly expose:
1. The exergy balance proved to be way more accurate than the energy balance. Such analysis was made on the whole process and, for those not familiar with it, the main results were obtained for heat exchangers, boilers, turbines, generators, heating pans, evaporators, condensate and steam lines, mills, condensators and technical solutions / mix of solutions.
2. The first step was to complete the energy and mass balance which gave a full panorama of the process. The mass balance had to be re checked since the conventional approach gave results not representative enough. The margin of error was 1% for this step.
3. The energy balance had to be suported by thermochemical analysis for water sucrose solutions which ended up in the creation of a pilot simulation software that handled a 0.2% error.
4. The mass and energy balances were checked by 3 independent groups of sugar technologists and the results obtained were that the new approach was more accurate and reliable even when transient conditions were analyzed.
5. The exergy analysis on all the equipments except turbines gave results that confirmed that energy analysis is just a rough look at the problem. Involving energy availability and exergetic modeling we were able to obtain results that pointed right to the particular place were degradation of energy was occuring, not just heat transfers, but the whole thermic phenomena.
6. The results on turbines were higher than those obtained with energy balances. Theoretically, this is the result expected given the way a turbine operates. Further analysis on this matter will be conducted soon using two new approaches.
7. The exergy balance of the boiler made possible to increase its efficiency in 15% (energy base, 5% exergy) just by making a few changes in air inlets and condensate returns and superheater.
The modeling will now be applied to a power station moved by charcoal whose operation is quite efficient. If the model has the amplitud I expect it will be able to increase the facility's efficiency a couple of points up.
Although energy analysis can give us a fair idea of the problem and ways to fix it, exergy analysis should be applied later on to be sure the problem was solved or to re check a plant with good operational quality.
Thank to all those that helped me on this matter. Hope this could bring some further discussion on the topic so that we can try this technique on other processes and systems.
Regards to all
MAEC
A few months ago I came to this forum asking for tips on energy balances and exergy analysis for a sugar industry project. Since the begining of the project, which lasted 26 months, I often came here for replies on such inquiry but just a few were given. Now I am back to let those that were interested in its moment that the project was succesfully finished and amazing results were obtained, results I will briefly expose:
1. The exergy balance proved to be way more accurate than the energy balance. Such analysis was made on the whole process and, for those not familiar with it, the main results were obtained for heat exchangers, boilers, turbines, generators, heating pans, evaporators, condensate and steam lines, mills, condensators and technical solutions / mix of solutions.
2. The first step was to complete the energy and mass balance which gave a full panorama of the process. The mass balance had to be re checked since the conventional approach gave results not representative enough. The margin of error was 1% for this step.
3. The energy balance had to be suported by thermochemical analysis for water sucrose solutions which ended up in the creation of a pilot simulation software that handled a 0.2% error.
4. The mass and energy balances were checked by 3 independent groups of sugar technologists and the results obtained were that the new approach was more accurate and reliable even when transient conditions were analyzed.
5. The exergy analysis on all the equipments except turbines gave results that confirmed that energy analysis is just a rough look at the problem. Involving energy availability and exergetic modeling we were able to obtain results that pointed right to the particular place were degradation of energy was occuring, not just heat transfers, but the whole thermic phenomena.
6. The results on turbines were higher than those obtained with energy balances. Theoretically, this is the result expected given the way a turbine operates. Further analysis on this matter will be conducted soon using two new approaches.
7. The exergy balance of the boiler made possible to increase its efficiency in 15% (energy base, 5% exergy) just by making a few changes in air inlets and condensate returns and superheater.
The modeling will now be applied to a power station moved by charcoal whose operation is quite efficient. If the model has the amplitud I expect it will be able to increase the facility's efficiency a couple of points up.
Although energy analysis can give us a fair idea of the problem and ways to fix it, exergy analysis should be applied later on to be sure the problem was solved or to re check a plant with good operational quality.
Thank to all those that helped me on this matter. Hope this could bring some further discussion on the topic so that we can try this technique on other processes and systems.
Regards to all
MAEC
