scholarly journals PEMODELAN TEMPERATUR DARI PROSES PEMBAKARAN DI REFORMER FURNACE PADA INDUSTRI BAJA

2020 ◽  
Vol 16 (1) ◽  
pp. 25-30
Author(s):  
Trisaksono Bagus Priambodo

Conversion processes that involve large amounts of energy include processes in furnace reformers inthe steel industry. The reformer unit used to convert the process gas, namely a mixture of gas andsteam into CO and H2 gas with the help of a nickel catalyst. The heat energy used in the process is theresult of combustion from natural gas using combustion located above the furnace. The most importantthing in the conversion process is the radiative heat transfer in the combustion chamber to the reactionpipe wall so that enough energy is obtained to carry out the conversion process. One way to determinethe heat distribution of the reformer combustion chamber is to know the temperature profile along thereaction pipe, including the pipe wall temperature, the process gas temperature, and the temperatureof the combustion gas used as energy for the process in the reformer furnace. The performanceevaluation of the reformer furnace uses a mathematical model for combustion in the furnace which canlater be developed by knowing the fitting composition of the conversion results. The type of reformerstudied is the top-fired reformer. The results of modeling using data from the steel industry obtained thehighest temperature from the combustion of gas from the burner which is in the reaction pipe at aposition 3-4 meters from the upper end of the reformer around 1300 oC and the temperature of naturalgas-steam in the pipe reaches 860 oC at the end of the pipe. reaction. The pipe wall heating with naturalo ogas fuels provides a maximum temperature ranging from 890 C - 895 C on the outer wall of thereaction pipe, and the pressure inside the reaction pipe ranges from 8.0-8.5 atm.

2020 ◽  
Vol 04 ◽  
Author(s):  
Guohai Jia ◽  
Lijun Li ◽  
Li Dai ◽  
Zicheng Gao ◽  
Jiping Li

Background: A biomass pellet rotary burner was chosen as the research object in order to study the influence of excess air coefficient on the combustion efficiency. The finite element simulation model of biomass rotary burner was established. Methods: The computational fluid dynamics software was applied to simulate the combustion characteristics of biomass rotary burner in steady condition and the effects of excess air ratio on pressure field, velocity field and temperature field was analyzed. Results: The results show that the flow velocity inside the burner gradually increases with the increase of inlet velocity and the maximum combustion temperature is also appeared in the middle part of the combustion chamber. Conclusion: When the excess air coefficient is 1.0 with the secondary air outlet velocity of 4.16 m/s, the maximum temperature of the rotary combustion chamber is 2730K with the secondary air outlet velocity of 6.66 m/s. When the excess air ratio is 1.6, the maximum temperature of the rotary combustion chamber is 2410K. When the air ratio is 2.4, the maximum temperature of the rotary combustion chamber is 2340K with the secondary air outlet velocity of 9.99 m/s. The best excess air coefficient is 1.0. The experimental value of combustion temperature of biomass rotary burner is in good agreement with the simulation results.


Author(s):  
A. V. Sudarev ◽  
J. I. Zakharov ◽  
G. N. Ljubchik ◽  
L. S. Butovsky ◽  
E. A. Granovskya

The most effective method of increasing the thermal efficiency of a simple cycle gas turbine unit involves elevation of the gas temperature upstream of the turbine. This requires development of appropriate operational procedure principles and adequate combustion chamber design.


2003 ◽  
Vol 2 (1) ◽  
pp. 41-55 ◽  
Author(s):  
Alison Fuller ◽  
Lorna Unwin

This article argues that researching the lived reality of apprenticeship in contemporary workplaces provides a useful lens through which workplace learning more generally can be examined. Drawing on data from a 3-year study of the social and pedagogical relationships between apprentices and older workers in the English steel industry, the article proposes that, building on Engeström's work, an ‘expansive’ as opposed to a ‘restrictive’ approach to apprenticeship will not only deliver the broader goals being set for apprenticeship programmes around the world, but will also foster workplace learning. The article offers a critique of Lave and Wenger's novice to expert conceptualisation of apprenticeship and, using data from employee learning logs, argues that pedagogical relationships between apprentices and older workers need to be better understood. A conceptual framework for analysing the relationship between organisational culture and history, work organisation, and workplace learning is provided.


Author(s):  
SS Talebi ◽  
AM Tousi ◽  
A Madadi ◽  
M Kiaee

Recently, the utilization of micro gas turbines in smart grids are rising that makes the part-load operation principal situation of the engine service. This leads to faster life consumption that increases the importance of the diagnostics process. Gas path analysis is an effective method for gas turbine diagnostics. Complex dynamics of gas turbine induces challenging conditions to perform applicable gas path analysis. This study aims to facilitate MGT gas path diagnostics through reducing the number of monitoring parameters and preparation a pattern for engine level and component level health assessment in both full and part load operation of a recuperated micro gas turbine. To attain this goal a model is proposed to simulate MGT off-design performance which is validated against experimental data in healthy and degraded operation modes. Fouling in compressor, turbine and recuperator and erosion in compressor and turbine as the most common degradations in the gas turbine are considered. The fault simulation is performed by changing the health parameters of gas path components. According to the result investigation, a matrix comprises deviation contours of four parameters, Power, fuel flow, compressor discharge pressure, and exhaust gas temperature is presented and analyzed. The analysis shows that monitoring these parameters makes it possible to perform engine level and component level diagnostics through evaluating a binary code (generated by mentioned parameter variations) against the fault effects pattern in different load fractions and fault severities. The simulation also showed that the most power drop occurred under the compressor fouling by about 8.7% while the most reduction in thermal efficiency is observed under recuperator fouling by about 7.84%. Furthermore, the investigation showed the maximum decrease in the surge margin induced by the compressor fouling during the lower part-load operation by about 45.7% while in the higher loads created by the turbine fouling by about 14%.


2013 ◽  
Vol 31 (1) ◽  
pp. 27 ◽  
Author(s):  
Ravind Kumar ◽  
Mark Stephens ◽  
Tony Weir

This paper analyses trends in temperature in Fiji, using data from more stations (10) and longer periods (52-78 years) than previous studies. All the stations analysed show a statistically significant trend in both maximum and minimum temperature, with increases ranging from 0.08 to 0.23°C per decade. More recent temperatures show a higher rate of increase, particularly in maximum temperature (0.18 to 0.69°C per decade from 1989 to 2008). This clear signal of climate change is consistent with that found in previous studies of temperatures in Fiji and other Pacific Islands. Trends in extreme values show an even stronger signal of climate change than that for mean temperatures. Our preliminary analysis of daily maxima at 6 stations indicates that for 4 of them (Suva, Labasa, Vunisea and Rotuma) there has been a tripling in the number of days per year with temperature >32°C between 1970 and 2008. The correlations between annual mean maximum (minimum) temperature and year are mostly strong: for about half the stations the correlation coefficient exceeds 60% over 50+ years. Trends do not vary systematically with location of station. At all 7 stations for which both trends are available there is no statistically significant difference between the trends in maximum and minimum temperatures.


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