Reno-Nord's reserve W-t-E plant brought under greater control through new regulation concept

Date: February; 04; 2011 | Author:
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Reno-Nord and Babcock & Wilcox Vølund have together implemented an upgrade of the control and regulation system of the reserve line Plant 3. We have thus optimised the combustion process so that all emission values can now be met, and so that fluctuations in steam production can be reduced.

The entire process was carried out in close collaboration between electricians and operators from Reno-Nord and engineers and technicians from Babcock & Wilcox Vølund. The project cycle lasted approximately three months, from the summer of 2010, when Babcock & Wilcox Vølund's engineers first inspected the plant, until it was tested in October of last year by the operators and approved by Reno-Nord's management. 

Babcock & Wilcox Vølund's significant experience in regulating new plants has also proven useful in upgrading older plants. Using a new regulation concept, we were able to achieve greater stability in steam production in order to meet emission values.

New regulation concept allows greater control of Reno-Nord's reserve line 

Reno-Nord is now enjoying greater steam production stability after Babcock & Wilcox Vølund modified the regulation concept of the Reno-Nord's reserve line Plant 3. Plant 3 will now remain within the established emission values and can now be used optimally during peak capacity or periods in which it is necessary to shut down the main line.

In October 2005 Reno-Nord, located in Aalborg, Denmark, opened Plant 4, a new waste-to-energy plant with a capacity of 20 tonnes per hour. The new plant replaced two old furnace lines from 1980, while Plant 3, a ten-tonne-capacity furnace line from 1991, was kept as a reserve line.
 
The old line had several excess emission incidents, which is why Reno-Nord and Babcock & Wilcox Vølund agreed to inspect and optimise the incineration process, so that the furnace line could meet today's environmental standards. The project lasted approximately three months, from early summer until October of 2010, during which the plant was commissioned, adjusted and approved.
 
The entire process was carried out in close collaboration between electricians and operators from Reno-Nord and engineers and technicians from Babcock & Wilcox Vølund. After Babcock & Wilcox Vølund had inspected the furnace line, the engineers made a draft for a new regulation concept and submitted it to Reno-Nord's technicians. The two parties then agreed upon their individual responsibilities. Reno-Nord's tasks included replacing some of the line's mechanical parts, while Babcock & Wilcox Vølund was responsible for implementing the system. Once everything was in place, the furnace line was tested, and, following a few minor adjustments, the regulation concept was approved.  

Regulation with side benefits 

The new regulation concept has brought about several advantages.
 
Jasper Markussen , a process engineer with Babcock & Wilcox Vølund, explains: "We have a great deal of experience in control, regulation and monitoring of new plants, and we are applying this experience to optimise the regulation of older, existing plants. The goal is to obtain stable steam production. The problem with older plants can be, for example, that it is difficult to stay within the target emission values and/or that there are difficulties in maintaining the production level. In the event of major modifications - such as the implementation of water-cooled wear zones - there is also a need for a new regulation concept," explains Markussen, who continues: "We start with the operators' experiences with the problems they might have had in regulating and controlling production. After we've made a new regulation, the operators always tell us that it's become easier to regulate and control steam production".
 
This is the same feedback that Babcock & Wilcox Vølund received from Reno-Nord following last year's regulation:
 
"Even though our new Plant 4 handles our production on a daily basis, I do sleep better at night knowing that Plant 3 has been improved. Without a doubt it gives peace of mind knowing that we can use the reserve line whenever we need to," comments Reno-Nord's Operations Manager, Henrik Skov. "The furnace line underwent a 'service lifetime extension' in 2007, but the incineration process still wasn't properly under control. It is today, though. The main objective of implementing the new regulation concept was to stay within the emission values, and as a side benefit, we are now closer to our set point - and steam production is now more stable," explains Skov. 
   

"Even though our new Plant 4 handles our production on a daily basis, I do sleep better at night knowing that Plant 3 has been improved. Without a doubt it gives peace of mind knowing that we can use the reserve line whenever we need to," comments Reno-Nord's Operations Manager, Henrik Skov.    


"We start with the operators' experiences with the problems they might have had in regulating and controlling production. After we've made a new regulation, the operators always tell us that it's become easier to regulate and control steam production," says Jasper Markussen of Babcock & Wilcox Vølund. 
   
 
Flue gas oxygen variation and CO emissions after. (Red graph: Flue gas oxygen variation. Blue graph: CO emissions)
 
    
 
Steam flow after the restructuring of the regulation system at Reno-Nord. (Light blue graph: Steam set point. Green graph: Steam flow process value). Steam production variation was significantly reduced, and within a sample period of 24 hours this variation was shown to lie within the range +/- 2.2%. Only a few, justifiable cases of excess CO levels and below-level flue gas temperatures have been registered in the post-incineration zones.  

The project process for optimising combustion regulation 

We divide our work into two main phases:
 
Phase 1

  • Review of the plant to inspect and establish its potential in optimising the regulation principle.
  • Reporting 
Phase 2
  • Necessary updating of the plant's equipment, as well as project planning, implementation and commissioning of the regulation system.
  • Training and final documentation.

The entire process was carried out in close collaboration between electricians and operators from Reno-Nord and engineers and technicians from Babcock & Wilcox Vølund. The project cycle lasted approximately three months, from the summer of 2010, when Babcock & Wilcox Vølund's engineers first inspected the plant, until it was tested in October of last year by the operators and approved by Reno-Nord's management. 

Babcock & Wilcox Vølund's significant experience in regulating new plants has also proven useful in upgrading older plants. Using a new regulation concept, we were able to achieve greater stability in steam production in order to meet emission values.

Related information

The new furnace line 4 at Reno-Nord

More electricity from waste, Reno-Nord

Advanced combustion control




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