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| Articles
by
A.L. Tamiru |
Total Records (
3 ) for
A.L. Tamiru |
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A.L. Tamiru
,
F.M. Hashim
and
C. Rangkuti
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This study presents the result of an attempt to develop compressor and turbine maps for a 5.2 MW rated industrial gas turbine. The research is motivated by the need to study load accepting and load rejection characteristics of cooperating gas turbines. Only overall performance parameters of the gas turbine are provided by the manufacture and that made it difficult to carry out such studies. This work proposes the use of scaling method in the fixed geometry region and stage-stacking method in the variable geometry region. Generalized stage and overall component performance curves, all from literature, are used in presenting the performance maps. Characteristics of compressors whose actual maps are known are first used to choose a reference map. Relying on the selected map, predicted performance curves are obtained for the aforesaid gas turbine. The variable geometry is demonstrated considering actual data from literature. Having the design point parameters from limited overall performance data, the proposed approach has managed to get the key performance maps. The results can be used for stability, performance optimization and condition monitoring studies. |
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M. Amin A. Majid
,
A. Zainuddin
and
A.L. Tamiru
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Performance analysis, optimization and environmental load assessment of an absorption system
requires accurate but simplified models. The objective of the present study is to develop such models based
on non-dimensional parameters (part load ratio, part-load factor and diverter damper position) and ordinary least
squares. Since for the case study, the hourly, daily and monthly load demands data are available, the method
of averaging over eight years is considered. The models are developed for a system comprised of two heat
recovery steam generators and two steam absorption chillers. It was observed that the proposed method is
effective in providing better picture of the relationships between the supplied heat and the amount of energy
recovered by each subsystem. The maximum cooling load experienced by the two chillers was about 2392RT,
which is 4.32% lower than the design capacity. The steam generators were found operating at part load ratio
of about 0.41 only. Both chillers deteriorated in performance within the study period. This was confirmed by
the part load ratio of 0.8 and steam consumption higher than that required for a new chiller. A generalized model
was also identified for the two chillers with the correlation coefficient (R2), chi-square (χ2) and Root Mean
Squared Error (RMSE) equals to 0.9996, 1.9765e-5 and 0.0044, respectively. The model was found accurate for
cooling water temperatures in the range of 29 to 32°C. |
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M. Amin A. Majid
,
Shaharin A. Sulaiman
,
Hamdan Mokhtar
and
A.L. Tamiru
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As part of a tri-generation plant, an absorption process provides
the means to recover the energy that otherwise would be lost to the environment.
Since the overall efficiency relies on the amount of energy recovered in all
subsystems, knowing the current performance of the absorption process is vital
to proper management of the resources. This study proposes the use of data clustering
technique to estimate the most frequent operating point experienced by the absorption
system in a given year. The same technique is applied to identify operating
point trajectory of the system over nine years. In order to demonstrate applicability
of the proposed approach, an absorption system that is comprised of two 12 ton
h-1 heat recovery steam generators and two 1250 RT double-effect
LiBr-H2O steam absorption chillers is considered as a case study.
It was observed that data clustering technique is an effective method in establishing
the relationships between the supplied heat and the amount of energy recovered
by each subsystem. The heat recovery steam generators were identified as operating
at part load ratio of about 0.41. The clustering method clearly revealed that
both chillers deteriorated in performance. The absorption systems were mostly
run at part load ratio of about 0.8. As such, at this operating point the energy
demand was by 43% higher than that required for a healthy system. The proposed
technique is applicable for performance monitoring, optimization and multi-state
reliability studies of the absorption system. |
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