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The impact of vapour compression refrigeration is the main push for scientists to find an alternative sustainable technology. Vapour absorption is an ideal technology which makes use of waste heat or renewable heat, such as biomass, to drive absorption chillers from medium to large applications. In this paper, the aim was to investigate the feasibility of a biomass driven aqua-ammonia absorption system. An estimation of the solid biomass fuel quantity required to provide heat for the operation of a vapour absorption refrigeration cycle (VARC) is presented; the quantity of biomass required depends on the fuel density and the efficiency of the combustion and heat transfer systems. A single-stage aqua-ammonia refrigeration system analysis routine was developed to evaluate the system performance and ascertain the rate of energy transfer required to operate the system, and hence, the biomass quantity needed. In conclusion, this study demonstrated the results of the performance of a computational model of an aqua-ammonia system under a range of parameters. The model showed good agreement with published experimental data.
Munyeowaji Mbikan; Tarik Al-Shemmeri. Computational Model of a Biomass Driven Absorption Refrigeration System. Energies 2017, 10, 234 .
AMA StyleMunyeowaji Mbikan, Tarik Al-Shemmeri. Computational Model of a Biomass Driven Absorption Refrigeration System. Energies. 2017; 10 (2):234.
Chicago/Turabian StyleMunyeowaji Mbikan; Tarik Al-Shemmeri. 2017. "Computational Model of a Biomass Driven Absorption Refrigeration System." Energies 10, no. 2: 234.
Purpose This paper aims to present experimental results of gasoline-fuelled engine operation of a crankcase-scavenged two-stroke cycle engine used for unmanned air vehicle (UAV)/unmanned air system application and to cross correlate with computational fluid dynamic modelling results. Design/methodology/approach Computational modelling of the engine system was conducted using the WAVE software supported by the experimental research and development via dynamometer testing of a spark ignition UAV engine to construct a validated computational model exploring a range of fuel delivery options. Findings Experimental test data and computational simulation have allowed an assessment of the potential advantages of applying direct in-cylinder fuel injection. Practical implications The ability to increase system efficiency offers significant advantages in terms of maximising limited resources and extending mission duration capabilities. The computational simulation and validation via experimental test experience provides a means of assessment of possibilities that are costly to explore experimentally and offers added confidence to be able to investigate possibilities for the development of similar future engine designs. Originality/value The software code used has not been applied to such crankcase-scavenged two-stroke cycle engines and provides a valuable facility for further simulation of the twin cylinder horizontally opposed design to offer further system optimisation and exploration of future possibilities.
Peter Hooper; Tarik Al-Shemmeri. Improved efficiency of an unmanned air vehicle IC engine using computational modelling and experimental verification. Aircraft Engineering and Aerospace Technology 2017, 89, 184 -192.
AMA StylePeter Hooper, Tarik Al-Shemmeri. Improved efficiency of an unmanned air vehicle IC engine using computational modelling and experimental verification. Aircraft Engineering and Aerospace Technology. 2017; 89 (1):184-192.
Chicago/Turabian StylePeter Hooper; Tarik Al-Shemmeri. 2017. "Improved efficiency of an unmanned air vehicle IC engine using computational modelling and experimental verification." Aircraft Engineering and Aerospace Technology 89, no. 1: 184-192.
This paper presents a computer model that will evaluate the performance of a thermo-chemical accumulator. The model is based on operational data such as temperatures and flow rates. The ultimate goal for this model is to estimate the coefficient of performance (COP) of this unit when run on hot water from biomass combustion as the heat source. The outputs of the model are verified by comparing the simulation of the actual machine with published experimental data. The computed results for cooling COP are within 10% of the measured data. The simulations are all run for heat load temperatures varying between 80 °C and 110 °C. As expected, simulation results showed an increase in COP with increased heat source temperatures. The results demonstrate that the potential of combined solar and biomass combustion as a heat source for absorption cooling/heating in climates with low solar radiation can be coupled with biomass waste.
Sacha Oberweis; Tariq Al-Shemmeri. Performance Evaluation of a Lithium-Chloride Absorption Refrigeration and an Assessment of Its Suitability for Biomass Waste Heat. Applied Sciences 2012, 2, 709 -725.
AMA StyleSacha Oberweis, Tariq Al-Shemmeri. Performance Evaluation of a Lithium-Chloride Absorption Refrigeration and an Assessment of Its Suitability for Biomass Waste Heat. Applied Sciences. 2012; 2 (4):709-725.
Chicago/Turabian StyleSacha Oberweis; Tariq Al-Shemmeri. 2012. "Performance Evaluation of a Lithium-Chloride Absorption Refrigeration and an Assessment of Its Suitability for Biomass Waste Heat." Applied Sciences 2, no. 4: 709-725.
During biomass combustion, a number of physical and chemical processes occur in time and space during the combustion. The processes include: drying and preheating of the fuel, pyrolytic release of volatile matter, glowing combustion char, etc. In general the combustion of biomass produces, next to energy, ash, carbon dioxide and monoxide, unburnt hydrocarbons, oxides of nitrogen, particulate matter. This paper investigates characteristics of different biomass samples, such as the moisture, ash and fixed carbon content and the volatile matter. The paper tries to find a correlation for fuels from the North-West European region with their higher heating values. These correlations are compared to previous publications. Furthermore, the paper presents a performance and emissions evaluation for 40 kW biomass boiler. The results show that biomass is a valuable option for energy generation and the reduction of GHG gases.
Sacha Oberweis; T.T. Al Shemmeri. Emissions and performance from a biomass boiler for different solid biomass fuels. International Journal of Renewable Energy Technology 2012, 3, 323 .
AMA StyleSacha Oberweis, T.T. Al Shemmeri. Emissions and performance from a biomass boiler for different solid biomass fuels. International Journal of Renewable Energy Technology. 2012; 3 (4):323.
Chicago/Turabian StyleSacha Oberweis; T.T. Al Shemmeri. 2012. "Emissions and performance from a biomass boiler for different solid biomass fuels." International Journal of Renewable Energy Technology 3, no. 4: 323.
S. Oberweis; T.T. Al-Shemmeri. ɣ-Stirling engine- The effect of different working gases and pressures. Renewable Energy and Power Quality Journal 2011, 315 -320.
AMA StyleS. Oberweis, T.T. Al-Shemmeri. ɣ-Stirling engine- The effect of different working gases and pressures. Renewable Energy and Power Quality Journal. 2011; ():315-320.
Chicago/Turabian StyleS. Oberweis; T.T. Al-Shemmeri. 2011. "ɣ-Stirling engine- The effect of different working gases and pressures." Renewable Energy and Power Quality Journal , no. : 315-320.
This paper presents an algorithm which correlates nitrogen oxides emitted and the combustion flame temperature during the combustion of biodiesel. An iterative process is used to determine the flame temperature taking into account the phenomenon of dissociation. The results of the algorithm are presented for different blends and air-to-fuel ratios. These predicted results are compared with laboratory tests conducted in the present study on a stationary diesel engine run on different blends of biodiesel. Within the range of tests carried out, the NOx emissions from biodiesel and its blends proved to be higher than those of petro-diesel fuel. Furthermore, in this study a strong correlation was found relating the NOx emissions and the flame temperature.
T.T. Al-Shemmeri; S. Oberweis. Correlation of the NOx emission and exhaust gas temperature for biodiesel. Applied Thermal Engineering 2011, 31, 1682 -1688.
AMA StyleT.T. Al-Shemmeri, S. Oberweis. Correlation of the NOx emission and exhaust gas temperature for biodiesel. Applied Thermal Engineering. 2011; 31 (10):1682-1688.
Chicago/Turabian StyleT.T. Al-Shemmeri; S. Oberweis. 2011. "Correlation of the NOx emission and exhaust gas temperature for biodiesel." Applied Thermal Engineering 31, no. 10: 1682-1688.
This paper presents an investigation into the effect of biodiesel blending on emissions and efficiency in a stationary diesel engine. Rapeseed based biodiesel blended in increments of 25% with fossil diesel. The emissions of CO
S. Oberweis; T.T. Al Shemmeri. Emissions and performance of a stationary diesel engine run on biodiesel blends. International Journal of Oil, Gas and Coal Technology 2011, 4, 375 .
AMA StyleS. Oberweis, T.T. Al Shemmeri. Emissions and performance of a stationary diesel engine run on biodiesel blends. International Journal of Oil, Gas and Coal Technology. 2011; 4 (4):375.
Chicago/Turabian StyleS. Oberweis; T.T. Al Shemmeri. 2011. "Emissions and performance of a stationary diesel engine run on biodiesel blends." International Journal of Oil, Gas and Coal Technology 4, no. 4: 375.
S. Oberweis; T.T. Al-Shemmeri. Effect of Biodiesel blending on emissions and efficiency in a stationary diesel engine. Renewable Energy and Power Quality Journal 2010, 1, 304 -310.
AMA StyleS. Oberweis, T.T. Al-Shemmeri. Effect of Biodiesel blending on emissions and efficiency in a stationary diesel engine. Renewable Energy and Power Quality Journal. 2010; 1 (8):304-310.
Chicago/Turabian StyleS. Oberweis; T.T. Al-Shemmeri. 2010. "Effect of Biodiesel blending on emissions and efficiency in a stationary diesel engine." Renewable Energy and Power Quality Journal 1, no. 8: 304-310.