ΤHE SCIENTIFIC ENERGY SAVING PROJECT OF SEMANIN FIBRAN SA, TERPNI SERRON, GREECE.

Α. FIBRAN INSULATION MATERIALS

FIBRAN (www.fibran.gr)  was   founded   in   1974   and   since   1995   it   plays   a   leading role as a producer of insulation materials both in Greece and in Europe. 

Today,   FIBRAN   has 6   production units,   utilizing   the   latest   technology   for the manufacture   of   insulation   products   (Extruded   Polysterene,   Stonewool   and Expanded Polysterene), as well as Gypsum Boards.

In Greece,   in the  industrial  plant  located  in the Village of Terpni,  Serres,  FIBRAN produces  -   by   two   production   lines   GEO1   and   GEO2-  stonewool   insulation products with the brand name FIBRANgeo and extruded polysterene products with the brand name FIBRANxps.  

Picture 1: General plant view

The total installed electric power of GEO2 production line comes up to 7 MW. The grid is in 50Hz. The main load of the plant is the induction oven which fed by a Power Transformer of 4MVA at 21kV voltage level, while all the other loads are fed through a Transformer 21/0,4kV with rated power 2,5MVA. The average annual electricity cost of GEO2 production line is approximately 2.500.000 € in current prices.

1

Picture 2: GEO2 Production Line

Β. The scientific project of SEMAN SA

The   project   concerned   the   reduction   of   the   current   voltage   harmonics,   the improvement of motors’ and power transformers’ efficiency, the minimization of the reactive currents and the reduction of the consumed electrical energy in the inner of the plant’s electrical installation, as well. 

In   order   to   elaborate   the   scientific   study   for   FIBRAN’s   Electric   Power  Grid,   the engineer’s staff of SEMAN SA performed measurements and recordings – of all the required  electrical   values  –   in  each   individual   load  of   the   installation   (AC  &  DC motors,  motors  operating with  Inverters,   inductive furnaces,  DC Converters,  Star- Delta switches etc. both in Low and Medium Voltage).

2

Picture 1 : Laptops used for measurements and recordings

Measurements and recordings concerned the basic electric values (power, reactive power, voltage, current, frequency) as well as current & voltage harmonics (up to the 35th class) and transient phenomena.

Picture 2 : Measurements have been performed also in the core of the electrical installation next to the loads

Moreover the engineers’ staff of SEMAN SA proceeded to the collection of all the essential data that had to do with length   and cross-sections of cables, number of cables headed together in canals, nominal values of motors, power transformers and many others also necessary for elaborating the scientific study for the energy saving project.

3

Picture 3 : Measurements with special power quality analyzer

Based on the above, the engineers of SEMAN SA were able to simulate the behavior of FIBRAN’s Electric Power Grid and detect all the problems that were causing bad quality of voltage and current, low electric loads and power transformers efficiency, harmonic resonances and multiple other energy losses. 

The analysis of measurements and recordings showed that considerable harmonic sources existed inside FIBRAN’s Electric Network, producing harmonic currents and also considerable voltage harmonics.

Moreover, a number of energy saving scenarios, for the specific Electrical Power Grid – all based on the know-how of SEMAN SA – carried out by the use of simulations and finally the scientific study concluded 15 specialized interventions (please refer to pictures 6, 7, & 8 for low voltage loads and to pictures 9, 10 & 11 for medium voltage loads) that had been installed inside the Electric Power Network of FIBRAN. 

More specific:

12 interventions installed in parallel at LV network of 400V 2 interventions installed in series at LV network of 400V 1 intervention installed in parallel at MV network of 21kV.

The   total   installed   power   of   the   interventions   for   the   voltage-current   quality improvement and energy saving project was 2 MVA.

4

It should be mentioned that the design of interventions took into consideration not only the interaction with other electric loads of the network, but also the resonance frequencies of the electric power cables of the grid. 

The scientific project for energy saving and current - voltage quality improvement has been completed in October 2010. 

Picture 6: Low Voltage (LV) Variable Antiresonance Harmonic Filter

5

Picture7: Low Voltage (LV) Variable Antiresonance Harmonic Filter

Picture 8: Series Harmonic Reactor of the LV Antiresonance Harmonic Filter

The   customized   interventions   for   voltage-current   quality   improvement   are connected   in   parallel   or   in   series   to   the   electric   loads   and   lead   to   harmonics absorption   and   their   important   reduction   inside   the   electric   installation   of   the 

6

factory. Furthermore, resonance frequencies that could lead to dangerous tuning are being cut off. PLC with special design from SEMANS’s engineers, based on the results of the scientific study, control the dynamic operation of each intervention according to   the  fluctuations  of   the  electric   load  and  ensure   the   cutting  of   all   dangerous interactions between the loads.  

Picture 9: Medium Voltage (MV) Antiresonance Harmonic Filter

Picture 4 0 : Detail of Medium Voltage (MV) Antiresonance Harmonic Filter

7

Picture 11: Detail of the MV Antiresonance Harmonic Filter

C. Results – Benefits

After the completion of the project, measurements and recordings were performed that demonstrated significant reductions in currents, improvement of voltage levels, important reduction of current voltage harmonics,  and almost annihilation of the requested reactive power with power factors at central and local level in the limits of optimum one (1).

Table 1 presents the results.

Table 1. Synoptic Results of Power Quality Improvement and Saving Project accomplished for GEO2 production line of FIBRAN SA

Value ResultsGuaranteed saving according to the contract (%) -4,47%Saving achieved (%)(according also to the Reference Letter by FIBRAN) -7,84%

Guaranteed Pay Back Period of the project (months)

29,4

Real Pay Back Period of the project (months) 17

Annual Money Saving(€) 196.000,00 €

Furthermore, in the inner of the plant’s electrical installation and in depth of time after the completion of the Optimum Energy Management –Electric Energy Saving Project, the following were noticed:

8

1. Minimization of the problems created in the motors, such as windings burn.2. Reduction of the damages in contactors, fuses and switches and of the 

memory losses in PLC programs, due to the optimal power quality.3. Discharge of the electrical equipment (with expecting increase of its 

durability).4. Increase of the electrical installation reserve, due to great current reductions 

in its inside. New loads might be supplied by the existing equipment of electrical panels, cables. etc, without any additions in electrical material and further expenses.

9