Tnb Research Sdn Bhd

Kuala Selangor, Malaysia

Tnb Research Sdn Bhd

Kuala Selangor, Malaysia
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Othman N.F.,TNB Research Sdn Bhd | Bosrooh M.H.,TNB Research Sdn Bhd
Procedia Engineering | Year: 2016

Integrated Gasification Combined Cycle (IGCC) is an Advanced Clean Coal Technology and can be used as an option for future TNB coal-fired power plant. The implementation of this technology is expected to reduce Green House Gas emissions (eg. CO2), which caused global warming. However, there are several problems in IGCC system, including low carbon conversion and low efficiency in gasifier. Previous studies had shown that higher carbon conversion and efficiency only can be achieved at higher temperature of 900-1000oC. In this study, we had increased the carbon conversion and gasifier efficiency for Adaro coal gasification process using catalyst as in-bed material at lower operating temperature of 700-800oC. Dolomite and nickel with high catalytic activity are selected as catalysts. These catalysts will enhance tar cracking and production of syngas. Furthermore, dolomite is also cheap and abundantly available in Malaysia. Coal catalytic gasification tests were conducted using TNBR Pilot Scale Gasification Plant (PSGP). Adaro coal (100%), Adaro coal:dolomite (80:20) and Adaro coal:dolomite:nickel (90:9:1) mixtures were gasified using PSGP. The results showed that the presence of dolomite had increased Carbon Conversion (CC) and Gasification Efficiency (GE) about 3.1% and 30.7% respectively, compared to Adaro coal gasification. While, the presence of dolomite and nickel for Adaro coal:dolomite:nickel (90:9:1) gasification, had increased CC and GE about 9.5% and 16.4% compared to Adaro coal gasification. Lower increasing of the GE with the presence of nickel is expected due to the deactivation (poison) effect of H2S towards nickel during the gasification process. © 2016 The Authors. Published by Elsevier Ltd.

Abubakar I.,University of Technology Malaysia | Khalid S.N.,University of Technology Malaysia | Mustafa M.W.,University of Technology Malaysia | Shareef H.,Tnb Research Sdn Bhd | Mustapha M.,University of Technology Malaysia
Renewable and Sustainable Energy Reviews | Year: 2017

Energy monitoring is one of the important aspects of the energy management, as such there is a need to monitor the power consumption of a premises before planning some of the technical measures to minimize the energy consumption. This paper presents the current state of art of appliances’ energy management through Intrusive Load Monitoring (ILM) and Non-intrusive Load Monitoring (NILM), ILM is referred to as distributive sensing and NILM is based on single point sensing. In an effort to explore the recent trend in Energy Management for researchers in the area, various techniques of Home Energy Management (HEM) using ILM and NILM have been analyzed and categorized. Different contributions made by the researchers have been highlighted together with some techniques of reducing power consumption of a building for cost saving and greener environment. This study reveal that there are issues concerning load monitoring and load management that need the attention; issues such as more accurate recognition and the need for monitoring system that can recognize as many kind of loads as possible. More efforts to apply NILM in appliances’ energy management is also required. Finally there is need for promoting the energy management culture among the electricity consumers whether in homes, offices or industries. The study will help the researchers in the area to have a clear vision of the recent trends in the area. © 2016 Elsevier Ltd

Ahmed M.A.,University of Tenaga Nasional | Shuaib N.H.,Tnb Research Sdn Bhd | Yusoff M.Z.,University of Tenaga Nasional
International Journal of Heat and Mass Transfer | Year: 2012

In this paper, laminar copper-water nanofluid flow and heat transfer in a two-dimensional wavy channel is numerically investigated. The Reynolds number and nanoparticle volume fraction considered are in the ranges of 100-800 and 0-5% respectively. Numerical solutions are obtained by solving the governing equation of stream function, vorticity transport and energy in curvilinear coordinates using the finite difference method. The effects of nanoparticle volume fraction, the wavy channel amplitude and wavelength and the Reynolds number on the local skin-friction coefficient, local and average Nusselt number and the heat transfer enhancement are presented and discussed. Results show that the friction coefficient and Nusselt number increase as the amplitude of wavy channel increases. As the nanoparticle volume fraction increases, the Nusselt number is found to be significantly increased, accompanied by only a slight increase in the friction coefficient. In addition, it was found that the enhancement in heat transfer mainly depends on the nanoparticle volume fraction, amplitude of the wavy wall and Reynolds number rather than the wavelength. © 2012 Elsevier Ltd. All rights reserved.

Raymond W.J.K.,University of Tenaga Nasional | Raymond W.J.K.,University of Malaya | Chakrabarty C.K.,University of Tenaga Nasional | Hock G.C.,University of Tenaga Nasional | Ghani A.B.,Tnb Research Sdn Bhd
Measurement: Journal of the International Measurement Confederation | Year: 2013

Complex permittivity measurement has been performed using a parallel plate capacitor and a vector network analyzer (VNA) from 300 kHz to 50 MHz. The material under test (MUT) is a flat and thin sample clamped between the capacitor plates and connected to the VNA to obtain its two port S parameters. The S parameter is converted into impedance to calculate the complex permittivity using Matlab program. Techniques used to overcome the air gap and stray capacitance was described. Measurement obtained using the proposed method was compared with the free space method to validate its accuracy. The percent difference is less than 5%. © 2013 Published by Elsevier Ltd.

Amir M.D.M.,TNB Research Sdn Bhd | Muttalib E.S.A.,Tenaga Nasional
Proceedings of the 2014 IEEE 8th International Power Engineering and Optimization Conference, PEOCO 2014 | Year: 2014

Oil-filled ring main units (RMUs) are considered to pose a medium to high medium risk due to the severity of failure consequences and the ageing population. The obvious solution is to institute a network wide replacement program of oil-filled RMUs with the newer types of RMUs. However, a replacement program covering the total population of tens of thousands will take significant capital expenditure and time. This paper proposes a condition-based Health Index to determine the present condition of oil-filled RMUs and facilitate the decision making for their replacement. Seven condition indicators which cover different major components are used for the modelling of the RMU in the Health Index model. The criteria for determining the Health Index for each condition indicator is derived from manufacturer's data, IEC standards and other standards like IEEE, NETA and ASTM if the equivalent IEC standards are not available. The overall health index (HO) is then calculated based on the weighted sum of the individual condition indicator Health Index. The proposed Health Index method was then applied to test data collected from actual RMUs. © 2014 IEEE.

Ahmed M.A.,University of Anbar | Ahmed M.A.,University of Tenaga Nasional | Yusoff M.Z.,University of Tenaga Nasional | Shuaib N.H.,Tnb Research Sdn Bhd
International Communications in Heat and Mass Transfer | Year: 2013

In this article, laminar forced convection heat transfer of copper-water nanofluid in trapezoidal-corrugated channel has been numerically investigated. The two-dimensional governing continuity, momentum and energy equations in body-fitted coordinates are discretized using finite volume approach and solved iteratively using SIMPLE technique. In this study, the Reynolds number and nanoparticle volume fractions are in the ranges of 100-700 and 0-5%, respectively. The effect of geometrical parameters such as the amplitude and wavelength of the corrugated channel, nanoparticle volume fraction and Reynolds number on the velocity vectors, temperature contours, pressure drop and average Nusselt number have been presented and analyzed. The results show that the average Nusselt number enhances with increase in nanoparticles volume fraction and with the amplitude of corrugated channel but this enhancement accompanied by increases in pressure drop. In addition, as the wavelength of corrugated channel decreases, the average Nusselt number increases and the pressure drop decreases. © 2012 Elsevier Ltd.

Hussin A.K.M.,Tnb Research Sdn Bhd | Wanik M.Z.C.,Tnb Research Sdn Bhd
IOP Conference Series: Earth and Environmental Science | Year: 2013

Advance control employed in microturbine generation system (MTGS) is expected to improve its performance in responding to grid faults. This paper compares the effect of advance control of MTGS power conversion topology on the performance in riding through the grid faults. The analysis and investigation study through simulation shows there is no significant different on MTGS output performance even advance control is employed for its rectifier. © Published under licence by IOP Publishing Ltd.

Othman N.F.,TNB Research Sdn Bhd | Boosroh M.H.,TNB Research Sdn Bhd
Advanced Materials Research | Year: 2014

Ash is a by-product of solid fuels (eg. coal, biomass, petroleum coke) gasification, which can contribute to the gasifier performance. Continuous formation of ash slag will further accumulate and cause plant outage. In relation to that problem, this study is conducted to mitigate the formation of ash slag in gasifier. Adaro coal from Indonesia and empty fruit bunch (EFB) were used as blends. EFB is used to promote the utilisation of renewable energy source and to reduce the Green House Gas Emission (eg. CO2). Adaro coal and EFB; and 4 blended fuels from Adaro:EFB at blending ratios of 80:20, 85:15, 90:10 and 95:5 were prepared in laboratory. Prediction of slagging tendency for Adaro:EFB blends were conducted using two slagging indices, which are slagging index, Basic/Acidic(B/A) and ratio-slag viscosity index (SR). Mineral oxides (eg. SiO2, Al2O3, Fe2O3) from the ashes of single and blended fuels were determined using Filed-Element Scanning Electron Microscopy (FESEM) and were used as input for the prediction of slagging tendency. The results showed that Adaro:EFB with blend ratio of 80:20 and 85:15 had low slagging tendency based on slagging index (B/A) and SR. Therefore, these two blending ratios are suitable to be used in the gasification system to avoid the ash slagging problem. © (2014) Trans Tech Publications, Switzerland.

Rahman M.R.A.,Tnb Research Sdn Bhd | Ridwan M.I.,Tnb Research Sdn Bhd
Advanced Materials Research | Year: 2014

The monitoring of dissolved combustible gases in power transformer oil could enable early detection of disastrous fault. The conventional dissolved gases in oil monitoring activities have these characteristic: 1) periodically sampling and 2) manual interpretation of combustible gases. However, periodical sampling increases number of undetected fault due to long sampling interval and manual interpretation of dissolved gas is often too complex for system operator to digest, resulting inreduced reliability of the power system and lack of situational awareness. To enhance the condition based monitoring activities for power transformer; TNB Research is embarking on online monitoring and knowledge-based system research project to address both issues related to periodical sampling method. This paper outlines the conceptual framework of the research project which was recently approved. It includes - (1) the system architecture of the online monitoring system, (2)brief explanation of the mechanism of photo-acoustic spectroscopy, (3)the engineering system situational awareness framework which integrates different levels of automation and (4)blocks of knowledge sources theory used in modeling the engineering system. © (2014) Trans Tech Publications, Switzerland.

Othman N.F.,TNB Research SDN Bhd | Boosroh M.H.,TNB Research SDN Bhd
IOP Conference Series: Earth and Environmental Science | Year: 2016

Synthetic gas or syngas is produced from the gasification process. Its main compositions are hydrogen, H2; carbon monoxide, CO; methane, CH4; carbon dioxide, CO2and nitrogen, N2. Syngas is a substitute for the depleting natural gas (80-90%.vol. CH4). Natural gas is combusted in gas turbine in gas-fired power plant to produce electricity. However, combustion of syngas using gas turbine is expected to show different behavior compared to natural gas combustion. This is because of H2 and CO contents in syngas have higher adiabatic flame temperature than CH4. In this study, different quality of syngas with different contents of H2 (0.6-0.8 %.vol.) and CO (1-3 %.vol.) were combusted using 30kW Micro Gas Turbine (MGT). Performances of different syngas quality were studied using NOx, CO, CO2 emissions and combustion efficiency parameters. NOx and CO are the main pollutants from the combustion process. NOx emissions were the highest for syngas with H2contents of 0.8 %.vol. and CO contents of 3 %.vol. CO emissions were in the range of 220-310 ppm for all the tested syngas. While, CO2 emissions were in the range of 0.96-1.06 % for all the tested syngas. Combustion efficiencies were reduced for syngas with CO contents of 1 %.vol. and H2 contents of 0.6-0.8 %.vol. This is most probably due to the dilution effect of N2in syngas.

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