Papers by Keyword: Efficiency

Abstract: In order to study the efficiency on hydro-mechanical transmission (HMT),this paper analyses the stepless speed regulation characteristic,torque characteristic and hydraulic power distributing characteristic of HMT.According to the calculating method of efficiency of the closed pump-motor system and planetary gear,the approximate efficiency formulas of HMT were established.The result shows that:the efficiency of HMT is much higher than that of hydrostatic transmission (HST),the peak efficiency of HMT can reach about 90% and the average efficiency of HMT can exceed more than 80%.

Abstract: Sugarcane bagasse was successfully developed to be used as immobilizing agent for Lactobacillus rhamnosus NRRL 442. Several different structural and morphology were obtained between the sugarcane bagasse and immobilized probiotic-sugarcane bagasse. Sugarcane bagasse was able to preserved high cell viability (~98%) after immobilization. Also it was shown that the bagasse was an excellent biomaterial for immobilizing Lactobacillus rhamnosus NRRL 442 and retaining the cell viability.

Abstract: Elimination gasoline vapor in oil tank by mechanical ventilation has disadvantages of long vent time poor safety, and low efficiency, however, those shortcomings can be better conquered if combusted gas is used in the process of the mechanical ventilation. Based on former studies, the research on the effects of inlet location on gasoline vapor’s inert replacement in oil tank by combusted inert gas is studied experimentally in this paper. The conclusions in this paper can provide some useful guidance for the field project of gasoline vapor’s inert replacement in oil tank.

Abstract: Different rotor bars type, lower in iron loss, total loss and thicknesses of steel sheets will increase the efficiency of the induction motor. In this paper, the 3-phase 0.5 Hp AC induction motor have been thoroughly investigated and analyzed in term of efficiency, torque, iron loss, total loss and loss field. The comparison is done by software simulation named MotorSolve (IM) that enable user to produces more design of induction motor with result in a short time. Based on simulation, it shows that the Round Bars (RO.B) have more efficient compared to Round Outer and Inner Bars (ROIB) type.

Abstract: – Decrease the iron loss, total loss and thicknesses of steel sheets will produce high efficiency of the induction motor This paper studies, a rotor construction with different thickness was investigated thoroughly and analyzed in the case of efficiency, torque, all losses and distribution field. All result simulation was done by MotorSolve (IM) which allows the user to produce more design of induction motor with a decision within a short time. According to simulation result, the 0.35 mm showed that a best performance and efficient compared to 0.50 mm thickness of rotor frame.

Abstract: Ongoing research and development of ultra-high performance concrete (UHPC) in the Czech Republic has been utilized in design and implementation of light-weight segmental deck of the cable-stayed footbridge over the Labe River in Celakovice with main span of 156 m. Detailing, design issues, construction method and efficiency of using UHPC on this large span lightweight bridge is described in the paper. The superstructure of the Celakovice footbridge was completed in the December 2013 and the bridge was opened for the public in April 2014. Main advantages of this project is not only low maintenance and reasonable life cycle cost but also favourable tender price which was achieved by the contractor Metrostav a.s. due to combination of high-strength modern materials steel and UHPC.

Abstract: The photovoltaic (PV) system output performance is not independent as it varies over extended periods as well as it depends on the varying atmospheric conditions. In this work, the effect of ambient temperature and relative humidity on the efficiency performance of the polycrystalline PV system was investigated and analyzed in a tropical region. This was done by using a measurement system consists of sensors for measuring both electrical of the system and the atmospheric parameters concurrently at interval of time for a period of a year at the back of Pure and Applied Physics Department, Ladoke Akintola University of Technology Ogbomoso, Nigeria. From the measurements obtained, it was deduced that the performance efficiency of the system varied with the variation in the magnitude of the atmospheric parameters. The maximum daily value of efficiency obtained was 55% between the ambient temperature and relative humidity of 33oC to 34oC and 50% to 55% respectively. This can serve as a baseline to the PV designers and users for adequate installation of the system in the study area and other areas that have similar solar characteristics.Key words: Photovoltaic, polycrystalline, solar cell, semiconductor, efficiency.Corresponding Author:

Abstract: The manuscript presents results of a 3 years experiment, concerning in the monitoring of working parameters of a ground – water heat pump with horizontal collectors. The measured working parameters of the refrigerant circuit are: evaporating pressure, condensing pressure, superheating temperature, discharge temperature, sub cooling temperature. There were also measured the flow rate and the temperatures on the heating circuit of water and on the horizontal collectors circuit with antifreeze. The methodology of data processing, described in the manuscript, allowed calculation of evaporating temperature and condensing temperature, based on measured corresponding pressures. The main obtained results consist in a complete set of working and performance parameters and their variation in 3 years of operation. Details are presented for operating conditions characteristic for different cases: middle of heating season, end of heating season, middle of non-heating season, beginning of heating season. Some practical conclusions of the study are also presented in the manuscript. It was indicated how the outside temperature is influencing the values of working and performance parameters, but mainly on the effective number of running periods.

Abstract: Currently, Combined Cycle Power Plants represent the most advanced technology in the domain of high and medium power generation units operating with fossil fuels. Consequently, the interest for their implementation in the propulsion systems field is justified. At this moment, Combined Cycle Units are used for propulsion only on ships (marine propulsion). The present study goes one step further by referring to a small scale Combined Cycle Unit configured for operation as terrestrial propulsion system and based on a two-pressure-levels Steam Cycle. The performances of this unit are analyzed function by the compressor pressure ratio and HRSG feed water temperature.

Abstract: Increasing the energy efficiency of a gas turbine plant can be achieved by exhaust gas heat recovery in a recovery boiler. Establishing some correlations between the parameters of the boiler and of the turbine is done usually based on mathematical models. In this paper it is determined from experimental point of view, the effectiveness of a heat recovery boiler, which operates together with a gas turbine power plant. Starting from the scheme for framing the measurement devices, we have developed a measurement procedure of the experimental data. For experimental data processing is applied the effectiveness - number of transfer unit method. Based on these experimental data we establish correlations between the recovery boiler effectiveness and the gas turbine plant characteristics. The method can be adapted depending on the type of flow in the recovery boiler.