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Schematic diagram of a steam boiler Theoretical framework of the laboratory fire-tube steam boiler For effective and efficient functioning of the boiler, important calculations to be carried out are enumerated as follows: 1. Operating temperature and pressure The operating temperature and pressure of a boiler must be determined in order to make other important calculations required for effective functioning of the boiler. 2. Stresses in tubes and drums Stresses are induced in different parts of an operating boiler by the temperatures and pressures of hot flue gases, feed water and steam respectively. The magnitudes of these stresses must be known so that the boiler will be operated under safe conditions.
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This paper presents the design of a laboratory fire-tube steam boiler for eventual construction and use as a teaching aid and for research purposes. Thermodynamics, heat transfer and strength of materials analysis were conducted to estimate dimensions of parts and 3D modelling process was used to draft the working drawings of the steam boiler. Oper...
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... Accurate prediction of heat transfer characteristics is of significant importance for boiler safety [6]. Several numerical and experimental studies have been conducted to understand the thermal-hydraulic behavior of conventional boilers [7][8][9][10]. In the past, traditional methods relied heavily on expensive experimentation and the building of scaled models, but now more flexible and cost-effective approaches are available through the use of CFD techniques and other advanced thermal-hydraulic system codes [11,12]. ...
This paper deals with a steady-state heat transfer analysis in a 4-pass fire-tube boiler. A computational program has been developed to study the heat transfer between the combustion gases and the boiler tube walls. On these surfaces, the energy balance was established, taking into account the heat transfer by convection and thermal radiation. The heat transfer characteristics, namely, the heat flux densities and the corresponding wall temperatures, are evaluated for different operating conditions. The modeling approach was validated by comparing the calculated outlet gas temperature against the experimental data, of the PFTA 500HP fire-tube boiler, for three types of fuels and various operating pressures. The comparison shows that the calculation results are in good agreement with the boiler's experimental data. A parametric analysis has also been conducted to investigate the working pressure effect on the boiler thermal behavior.
... A case study was studied and it was demonstrated that under these operating conditions, 90% CO 2 capture efficiency can be achieved with no energy penalty further than the one originated in the CO 2 compression system. Ohijeagbon et al. (2013) reported on the design of laboratory fire tube boiler for eventual construction and use as teaching aid and for research purposes, the design enables the availability of portable and affordable steam boiler for steam generation in school laboratory and to enhance research and students' learning process in area of thermodynamics, heat transfer and energy studies. ...
... This pressure is based on the nominal thickness. The internal design pressure is given by (Ohijeagbon et al., 2013). ...
... The minimum required wall thickness of a boiler is a value beyond which the boiler wall cannot be easily damage by the operation pressure in a boiler. The formula is given as (Ohijeagbon et al., 2013). ...
In this study, a miniature fluidised bed boiler for steam generation was designed and constructed. The boiler is made up of a steam drum, combustion chamber, downcomer and riser tubes as a heat exchanger, a non-return valve and superheater tube. Experimental investigation on the fuel distribution was carried in two-dimensional chamber with cross-section of 500 mm x 1000 mm and bed height of 77 mm, 47 mm and 27 mm. The results obtained from the performance evaluation of the fluidised bed boiler operated with corncob at constant feed rate of 6kg/h for various bed heights of 77 mm, 47 mm and 27 mm recorded stability in the saturation temperature of 121 o C at 50 minutes, 144 o C at 45 minutes and 153 o C at 30 minutes, respectively. In additional, saturation pressures of 2.0 bar from 50 to 55 minutes for bed height of 77 mm, 2.1 bar from 45 to 50 minutes for bed height of 47 mm and 3.6 to 3.7 bar from 45 to 55 minutes for bed height 27 mm were obtained. The effect of fuel particle size on emissions and over all combustion efficiency of corncobs has proven to be efficient in a fluidised bed boiler as the emission analysis of the flue gas has shown to be low in various percentages of 0.0003% of NO x , 0.001% HC, 0.02% of CO and 0.93% of Nitrogenm, respectively.
... A case study was studied and it was demonstrated that under these operating conditions, 90% CO 2 capture efficiency can be achieved with no energy penalty further than the one originated in the CO 2 compression system. Ohijeagbon et al. (2013) reported on the design of laboratory fire tube boiler for eventual construction and use as teaching aid and for research purposes, the design enables the availability of portable and affordable steam boiler for steam generation in school laboratory and to enhance research and students' learning process in area of thermodynamics, heat transfer and energy studies. ...
... This pressure is based on the nominal thickness. The internal design pressure is given by (Ohijeagbon et al., 2013). ...
... The minimum required wall thickness of a boiler is a value beyond which the boiler wall cannot be easily damage by the operation pressure in a boiler. The formula is given as (Ohijeagbon et al., 2013). ...
In this study, a miniature fluidised bed boiler for steam generation was designed and constructed. The boiler is made up of a steam drum, combustion chamber, downcomer and riser tubes as a heat exchanger, a non-return valve and superheater tube. Experimental investigation on the fuel distribution was carried in two-dimensional chamber with cross-section of 500 mm x 1000 mm and bed height of 77 mm, 47 mm and 27 mm. The results obtained from the performance evaluation of the fluidised bed boiler operated with corncob at constant feed rate of 6kg/h for various bed heights of 77 mm, 47 mm and 27 mm recorded stability in the saturation temperature of 121 o C at 50 minutes, 144 o C at 45 minutes and 153 o C at 30 minutes, respectively. In additional, saturation pressures of 2.0 bar from 50 to 55 minutes for bed height of 77 mm, 2.1 bar from 45 to 50 minutes for bed height of 47 mm and 3.6 to 3.7 bar from 45 to 55 minutes for bed height 27 mm were obtained. The effect of fuel particle size on emissions and over all combustion efficiency of corncobs has proven to be efficient in a fluidised bed boiler as the emission analysis of the flue gas has shown to be low in various percentages of 0.0003% of NO x , 0.001% HC, 0.02% of CO and 0.93% of Nitrogenm, respectively.
... al. [2] construct a dry steam boiler incorporated with super heater that was electrically operated. Waheed et al. [3] projected the laboratory steam boiler designed from the conceptual physical geometry of fire-tube boiler which elucidated the primary units making up a boiler. Dimensions of major and secondary parts were estimated from computations from the theoretical framework and 3D modelling process for the steam boiler was then carried out to present various working drawings of the steam boiler for possible construction. ...
This paper presents the design, construction and performance evaluation of steam boiler. It is aimed at improving an existing steam boiler through the incorporation of a heating element and a thermostat. The joining techniques and handling of the equipment for optimum usage was explained in details. The INVENTOR design shows the pictorial views, lines and dimensions for its mass production purposes. The electric steam boiler was put to test in order to determine its function ability and effectiveness through some experiment. When the electric steam boiler was tested, higher efficiency is obtained when compared with the already existing one. Therefore, it can be deduced that the constructed boiler can be operated with optimum efficiency when compared with existing one.
... Operational data of a fire tube steam boiler that uses diesel as its fuel were used to illustrate the minimization technique being investigated in this study. Ohijeagbon et al., 2013 b [20] have obtained numerical values for the thermodynamic properties of material streams for this particular steam boiler. ...
This paper presents a parametric study on fire-tube steam boilers’ heat exchanging unit using Entropy Generation Minimization (EGM) technique. Mathematical equation that models entropy generation rate (Ṡgen), and entropy generation number (Ns), were formulated. The entropy generation number was related to the geometric features of the system. Solving the equations showed the effects of each geometric feature on both pressure drop and Ns. Correlation equation relating dimensionless fire-tube length to dimensionless tube diameter was also obtained. The obtained correlation equation is a tool to be incorporated into fire-tube steam boiler design, so as to account for entropy generation during design.
... Operational data of a fire tube steam boiler that uses diesel as its fuel were used to illustrate the minimization technique being investigated in this study. Ohijeagbon et al., 2013 b [20] have obtained numerical values for the thermodynamic properties of material streams for this particular steam boiler. ...
This paper presents a parametric study on fire-tube steam boilers’ heat exchanging unit using Entropy Generation Minimization (EGM) technique. Mathematical equation that models entropy generation rate (Ṡgen), and entropy generation number (Ns), were formulated. The entropy generation number was related to the geometric features of the system. Solving the equations showed the effects of each geometric feature on both pressure drop and Ns. Correlation equation relating dimensionless fire-tube length to dimensionless tube diameter was also obtained. The obtained correlation equation is a tool to be incorporated into fire-tube steam boiler design, so as to account for entropy generation during design.
... Operational data of a fire tube steam boiler that uses diesel as its fuel were used to illustrate the minimization technique being investigated in this study. Ohijeagbon et al., 2013 b [20] have obtained numerical values for the thermodynamic properties of material streams for this particular steam boiler. ...
This paper presents a parametric study on fire-tube steam boilers’ heat exchanging unit using Entropy Generation Minimization (EGM) technique. Mathematical equation that models entropy generation rate (Ṡgen), and entropy generation number (Ns), were formulated. The entropy generation number was related to the geometric features of the system. Solving the equations showed the effects of each geometric feature on both pressure drop and Ns. Correlation equation relating dimensionless fire-tube length to dimensionless tube diameter was also obtained. The obtained correlation equation is a tool to be incorporated into fire-tube steam boiler design, so as to account for entropy generation during design.
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