Experimental and numerical investigation on the performance of square cyclones with different vortex finder configurations

Abstract Energy costs account for an important share of the total costs of urban and suburban bus operators. The purpose of this paper is to expand empirical research on bus transit operation costs and identify the key factors that influence bus energy efficiency of the overall bus fleet of one operator and aid to the management of its resources. We estimate a set of multivariate regression models, using cross-section dataset of 488 bus drivers operating over 92 days in 2010, in 87 routes with different bus typologies, of a transit company operating in the Lisbon’s Metropolitan Area (LMA), Rodoviaria de Lisboa, S.A. Our results confirm the existence of influential variables regarding energy efficiency and these are mainly: vehicle type, commercial speed, road grades over 5% and bus routes; and to a lesser extent driving events such as: sudden longitudinal decelerations and excessive engine rotation. The methodology proved to be useful for the bus operator as a decision-support tool for efficiency optimization purpose at the company level.

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Influential Vectors in Fuel Consumption by an Urban Bus Operator

A comprehensive review on performance improvement of micro energy mechanical system: Heat transfer, micro combustion and energy conversion

Wind power has been receiving attention as the new energy resource in addressing the ecological problems of burning fossil fuels. Savonius wind rotor is a vertical axis wind turbines (VAWT) which has relatively simple structure and low operating speed. These characteristics make it suitable for areas with low average wind speed as in Indonesia. To identify the performance of Savonius rotor in generating electrical energy, this research experimentally studied the effect of fin addition for the 'S' shape of Savonius VAWT. The fin is added to fill the space in the blade in directing the wind flow. This rotor has two turbine blades, a rotor diameter of 1.1 m and rotor height of 1.4 m, used pulley transmission system with 1:4.2 multiplication ratio, and used a generator type PMG 200 W. The research was conducted during dry season by measuring the wind speed in the afternoon. The average wind speed in the area is 2.3 m/s with the maximum of 4.5 m/s. It was found that additional fin significantly increase the ability of Savonius rotor VAWT to generate electrical energy shown by increasing of electrical power. The highest power generated is 13.40 Watt at a wind speed of 4.5 m/s by adding 1 (one) fin in the blade. It increased by 22.71% from the rotor blade with no additional fin. However, increasing number of fins in the blade was not linearly increase the electrical power generated. The wind rotor blade with 4 additional fins is indicated has the lowest performance, generating only 10.80 Watt electrical power, accounted lower than the one generated by no fin-rotor blade. By knowing the effect of the rotor shape, the rotor dimension, the addition of fin, transmission, and generator used, it is possible to determine alternative geometry design in increasing the electrical power generated by Savonius wind turbine.

https://iopscience.iop.org/article/10.1088/1757-899X/288/1/012132/pdf

Performance ‘S’ Type Savonius Wind Turbine with Variation of Fin Addition on Blade

Repurposing abandoned wells for geothermal energy: Current status and future prospects

Organic Rankine Cycle is a technology that convert low-temperature heat sources intoa mechanical energy, and it can be used to produce electrical energy in a closed system. The heatsources can be received from renewable energy such as geothermal, solar, and biomass.Furthermore, the ORC system can also be used to increase energy efficiency in the industry byutilizing the waste heat produced. Therefore, there are two classification of the ORC system,namely a heat recovery system and binary power plant. Recently, the ORC system has made athrive in the geothermal power plant. The ORC system can be applied to resources with low tomedium temperature characteristics (<90°C - 150°C). This paper will present an overview of theimplementation, model, and innovation of ORC system technology in geothermal resources.

https://iopscience.iop.org/article/10.1088/1742-6596/1402/4/044064/pdf

Organic Rankine Cycle (ORC) in geothermal power plants

Water power is a renewable energy source which has great potential in replacing fossil energy for generating electricity. The aim of this research is to analyze the influence of vertical distance of water source (water head) and nozzle diameter on the electrical power generated by Pelton turbine. It used Pelton turbine type with 22 buckets (vanes) which employed a PMG 200 watts generator with 1 : 2 pulley transmission system. Four different values of nozzle diameter and three different values of water head were chosen as the design parameters of the turbine. The electrical power was measured in three replications for each combination of the design parameters. The research showed that water head and nozzle diameter significantly affect the power generated by the Pelton turbine. The higher the water head from the surface, the more power generated. It was found that the electric power linearly increases with the increasing of nozzle diameter. However, it reaches the peak in 9 mm nozzle diameter and is getting lower in a larger diameter. The highest electric power of 16.89 watt is observed by adjusting the water head on 4.6 m with 9 mm nozzle diameter. Those design parameters are able can produce a rotation speed at 320 rpm in the generator. By identifying the appropriate parameters, it is possible to have more power generated by the water turbine used for hydroelectric power generation plant.

https://iopscience.iop.org/article/10.1088/1757-899X/288/1/012108/pdf

Performance of Pelton Turbine for Hydroelectric Generation in Varying Design Parameters

Experimental Investigation of Wind Turbine Using Nozzle-lens at Low Wind Speed Condition

The performance of cyclone separator as the ash trapper in the gasification system was studied through the Computational Fluid Dynamic (CFD) using the finite volume method. The ash trapper system is important part due to the effect on the gasification process, in particular on the quality of Syngas (Synthesis Gas). Therefore, the aim of this study is to find the suitable of the cyclone separator in the gasification apparatus that can separate the syngas and particulates. The CFD simulation was performed to determine the effect of adding the counter-cone in the cyclone separator to the trend of the efficiency of ash separation, speed profile, and pressure drop in the gasification process. The Reynold Stress Model (RSM) was employed for the for swirl flows modelling accuracy. The efficiency of ash separation was predicted by using the flow velocity in the cyclone separator and the pressure drop in the vortex finder. Discrete Phase Model (DPM)-one-way coupling was used to predict the efficiency of collection. The results of this simulation show that by adding the counter-cone in the cyclone separator increasing the number of particulates trapped and the distribution efficiency of particle diameter. The cyclone separator with the counter-cone can trap the particle diameter less than 1 micro meter (μm) while the cyclone separator without the counter-cone cannot.

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Danar Susilo Wijayanto

Papers

Performance ‘S’ Type Savonius Wind Turbine with Variation of Fin Addition on Blade

Organic Rankine Cycle (ORC) in geothermal power plants

Performance of Pelton Turbine for Hydroelectric Generation in Varying Design Parameters

Experimental Investigation of Wind Turbine Using Nozzle-lens at Low Wind Speed Condition

The CFD Simulation of Cyclone Separator without and with the Counter-cone in the Gasification Process