Impact of Torsional Resonance in Turbine-Generator Shaft Due to Multiple EAF Operation

Islam, Md. Minarul; Chowdhury, A. Hasib

doi:10.9790/1676-1203015163

Cited by 2 publications

(6 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With respect to the EAF, the reported energy (electricity) requirement is only 440 kWh/t EAF steel produced (1.61 GJ/t EAF steel) [66], although this directly equates to approximately 0.36 kg CO2/kg EAF steel (assuming 820 g CO2/kWh using coal as an electricity source). This is significantly less than the above reported values and it is assumed that there is additional auxiliary equipment which has been taken into account to form the above significantly larger energy requirement and CO2 footprint.…”

Section: Carbon Footprint and Reduction Optionsmentioning

confidence: 99%

Evaluation of recycled galvanised steel as a resource for Zn production

Uys,

Becker,

Petersen

2024

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

The high reduction potential of zinc has enabled its extensive use in the steel industry as a protective galvanising coating. Galvanising, which consumes approximately 50-60% of the global production of zinc, significantly increases the life span of steel products and contributes towards addressing the costly global problem of corrosion. While there does not appear to be a readily available and agreed-upon annual quantity of galvanised steel produced, it has been estimated by the authors to be 320-390 Mt/a (equating to 15-20% of the annual steel production). Due to the various methods employed to galvanise steel and different steel shapes which are coated, there is no clarity on the average percentage of zinc which galvanised steel is comprised of. However, a zinc content of between 1.5-2.5% appears to correlate with the estimated annual galvanised steel production. The reprocessing of secondary zinc streams is becoming increasingly important due to legislation changes and increased consumer demand for recycled and low carbon metals. Within the steel industry this will include the recycling of galvanised scrap steel, using primary process routes, as well as the re-processing of waste streams, such as steel dusts, using additional technologies such as the Waelz kiln. Zinc associated with galvanised scrap steel would exclusively report to these dusts, and thus represents a key resource for recycled zinc. Although there are two main steel process routes preceding the galvanising process, the focus here is on the Electric Arc Furnace (EAF) process route due to its ability to incorporate high levels of secondary (zinc containing) steel feeds, and the dust produced typically contains economically recoverable levels of zinc. EAF dust production is estimated between 5-10 Mt/a at a zinc content of 10-36%. Failure to recover this zinc would represent a loss of 0.5-3.6 Mt Zn/a to waste. The Waelz kiln is the most prominent technology utilised to recover Zn from EAF dust. However, this process requires additional energy, and thus the associated carbon footprint needs to be included in the evaluation of the potential of Waelz oxide as a secondary Zn resource. To this end, model analysis of a simplified Waelz kiln using the HSC simulation software shows that the carbon footprint associated with the processing of EAF dust ranges from 4-12 kg CO2/kg Zn dust at 10 wt.% Zn in the dust to 1-4 kg CO2/kg Zn at 35 wt.% Zn in the dust.

show abstract

Section: Carbon Footprint and Reduction Optionsmentioning

confidence: 99%

Evaluation of recycled galvanised steel as a resource for Zn production

Uys,

Becker,

Petersen

2024

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

show abstract

“…Ref. [21], [23] Fig. 3 shows the observed primary side voltage and current waveforms in phase-a of the furnace transformer.…”

Section: Electric Arc Furnace Modelingmentioning

confidence: 99%

“…3 shows the observed primary side voltage and current waveforms in phase-a of the furnace transformer. Mentioned voltage and current waveforms can be expressed in (3) and (4) [13], [21]- [23].…”

Section: Electric Arc Furnace Modelingmentioning

confidence: 99%

“…The currents in phases-b and phase-c at the primary side of the furnace transformer can be represented in ( 5) and ( 6) [23].…”

Section: Electric Arc Furnace Modelingmentioning

confidence: 99%

“…Fig. 4 shows the FFTs of the feeder current measured at the furnace transformer and the point of common coupling (PCC) due to the injection of a signal with 16.8 Hz (=fh) in the system due to the EAF operation [21], [23].…”

Section: Electric Arc Furnace Modelingmentioning

confidence: 99%

See 2 more Smart Citations

Torsional Resonance Identification in Turbine-Generator Shaft Due to the Operation of Electric Arc Furnaces at Steel Mills in Bangladesh Power System

Islam,

Chowdhury,

Shafiullah

et al. 2023

IEEE Access

Self Cite

View full text Add to dashboard Cite

Many steel mills in Bangladesh use electric arc furnaces (EAFs) that can impact the generating units of the country's power system. The EAFs can cause power quality problems, such as the injection of the sub-synchronous frequencies (SSFs), which may be close to the torsional resonance (TR) frequency of the turbine generator shaft. As a result, the torsional oscillating torques may be amplified and pose a potential threat to the rotating shaft systems. This paper comprehensively investigates the torsional resonance caused by the operation of EAFs in the power grid. It simulates the power system of the Chittagong region with two steel mills with alternating current (AC) EAFs where the large power plants are represented with an equivalent generation at the Comilla-North point. The MATLAB simulation tools are used to model the threephase EAFs. To produce realistic characteristics of the EAFs, the resistances are modulated deterministically in the range of 1.20 to 45.5 Hz. Torsional mode frequencies in the turbine generator shafts are calculated using the Fast Fourier Transform (FFT) technique. The results show that the EAF operation amplifies the torsional oscillating torques in the turbine generator shaft. The turbine generator shaft in Raozan and Sikalbaha power plants exhibits a higher potential to be damaged because they are vulnerable to the potential threat of amplified torsional torques.

show abstract

Impact of Torsional Resonance in Turbine-Generator Shaft Due to Multiple EAF Operation

Cited by 2 publications

References 22 publications

Evaluation of recycled galvanised steel as a resource for Zn production

Evaluation of recycled galvanised steel as a resource for Zn production

Torsional Resonance Identification in Turbine-Generator Shaft Due to the Operation of Electric Arc Furnaces at Steel Mills in Bangladesh Power System

Contact Info

Product

Resources

About