Results Of Efficiency Calculations Research Articles

EFFECTIVENESS OF DECOY WATER TREATMENT ON REACTIVATORS AT PT GOODYEAR INDONESIA Tbk

PT Goodyear Indonesia Tbk is a tire manufacturing industry whose main need is the provision of water for steam boiler decoys. This water is obtained from groundwater and surface water such as river water which is then treated in a reactivator using one of the coagulants, namely PAC, so that impurities from river water can be removed, so the water is cleaner and can be used for steam boilers and does not interfere with a further decoy water treatment. This study aims to determine the effectiveness of water treatment in reactivators to be a reference for further treatment considerations at PT Goodyear Indonesia Tbk. The test result data showed the efficiency value between the inlet and outlet and compared it with the control limit set by the company. The efficiency test parameters consist of pH, conductivity, clarity measurement, and color measurement. Based on the results of efficiency calculations, several test parameters show that water treatment in reactivators at PT Goodyear Indonesia Tbk is still good and has a high-efficiency value.

Comparison of Marketing Efficiency in the Sheep-fattening Business Supply Chain Scheme in Langkat District

Aims: Analyze the economic efficiency of production and describe the supply chain scheme for the fattening sheep business in Sei Bingai District, Langkat Regency.
 Study Design: This type of research is quantitative descriptive research.
 Place and Duration of Study: The research was conducted from November 2022-January 2023 in Sei Bingai District, Langkat Regency.
 Methodology: Data collection techniques include several techniques, namely using questionnaires through Focus Group Discussions (FGD), in-depth interviews with respondents, document analysis, informal discussions, and direct observation. The data analysis method used is Economic Efficiency Analysis and System Supply Chain.
 Results: The results showed that 1) The marketing of fattening sheep in Sei Bingai District, Langkat Regency, has been efficient. This is proven by the results of efficiency calculations which show the efficiency of the three supply chain schemes is below 50%. Compared to the other two channels, scheme two is said to be the most efficient because the efficiency value is only 13.2%. In comparison, the highest efficiency value is in scheme three, followed by the first channel scheme. 2) The supply chain scheme for fattening sheep in Sei Bingai District, Langkat Regency, consists of producer breeders, agents, regional market intermediaries, and consumers.
 Conclusion: Improvements in performance indicators provide good performance results for the sheep-fattening supply chain. Efforts to improve the indicators of order fulfillment and compliance with standards are carried out by having good cooperation with suppliers. Companies must be more involved in handling the quality and quantity of fattening sheep.

ANALISIS EFISIENSI ENERGI PADA BOILER INDUSTRI TIPE FIRE-TUBE KAPASITAS 2TON/JAM DENGAN BAHAN BAKAR COMPRESSED NATURAL GAS (CNG) DI PT.X

ABSTRACT
 Boiler is a high pressure vessel or tank that functions to produce hot steam. Problems that often occur in the field on boiler machines are not efficient well when the work system or operating process in the field, especially when the process is under operating conditions on a fire tube boiler engine always experiences heat loss in the steam or steam system and the fuel system which affects the efficiency of the engine. fire tube boilers are not optimal for steam output. Therefore, with these conditions, it is necessary to calculate the efficiency of a good fire tube type boiler engine in order to meet the appropriate efficiency value standards in the operating process in the field. The method used in this study is the calculation of efficiency carried out by two methods, namely the direct method and the indirect method. Based on the results of efficiency calculations using the direct method, the efficiency value is 81.04%, while the results of calculations using the indirect method are 85.65%. The results of the calculation of efficiency values ​​that have been carried out from two methods, namely the direct and indirect methods meet the standard efficiency value of the boiler engine ≥ 80 %.
 
 Keywords: Fire Tube Boiler, Efficiency, Heat Loss, Direct and Indirect Method

An analytical study of average radiation efficiency of rotating annular plates in rotating frame

The chief objective of this present research is concerned with average sound radiation efficiency of a thin homogeneous rotating annular plate which subject to a transverse load in rotating coordinate system. The governing equation is solved by using Galerkin’s Method then the radiated sound power is obtained by using Rayleigh integral and the sound radiation efficiency is accordingly derived. Sound radiation pressure and sound radiation efficiency calculation results are separately verified by experiment and boundary element method (BEM) simulation. The influences of the rotating speed, geometry parameters, material parameter and boundary conditions on the sound radiation efficiency of the plate are analyzed. Results indicate that with the increase of the rotating speed, the sound radiation efficiency tends to shift to higher frequencies. Besides, with the decrease of the thickness, the sound radiation efficiency in low frequency range will increase while in medium and high frequency range will decrease. A similar conclusion is drawn in the study of Young's modulus. Finally, the phenomenon that different boundary conditions will change the distribution of sound radiation efficiency of the annular plate is observed by studying three most representative combinations of boundary conditions including clamped-free, free-free and simply supported-free.

A benchmark for Monte Carlo simulation in gamma-ray spectrometry

Monte Carlo (MC) simulation is widely used in gamma-ray spectrometry, however, its implementation is not always easy and can provide erroneous results. The present action provides a benchmark for several MC software for selected cases. The examples are based on simple geometries, two types of germanium detectors and four kinds of sources, to mimic eight typical measurement conditions. The action outputs (input files and efficiency calculation results, including practical recommendations for new users) are made available on a dedicated webpage.

Study on Calculation Method of Soluble Aerosol Removal Efficiency Under High Humidity Condition

Pool scrubbing is a potential method to removal aerosol under accident conditions of the nuclear power plants. The relative humidity of aerosol laden gas will increase when it passes through the liquid pool, which cause the hygroscopic growth of soluble aerosol. The hygroscopic growth of soluble aerosol can lead to the deviation of the size distribution of aerosol at the outlet of the liquid pool, resulting in a large error of the removal efficiency calculation results. In order to solve this problem, the size distribution of sodium chloride before and after penetrating the liquid phase was experimentally measured at gas flow rate of 4lpm and liquid height of 80 cm. Two methods of calculating the removal efficiency were proposed and compared. One method is directly calculating the removal efficiency by adding a diffusion drying tube before the aerosol laden gas enters the SMPS to reduce the relative humidity of sample gas below efflorescence point. Another method is modifying the aerosol size distribution and concentration curve by using the hygroscopic growth theory of soluble aerosols. The experiment results obtained by the two methods are in good agreement with the relative error within 20%.

The Impact of Predried Lignite Cofiring With Hard Coal in an Industrial Scale Pulverized Coal Fired Boiler

The paper presents the experimental and numerical study on the behavior and performance of an industrial scale boiler during combustion of pulverized bituminous coal with various shares of predried lignite. The experimental measurements were carried out on a boiler WP120 located in CHP, Opole, Poland. Tests on the boiler were performed during low load operation and the lignite share reached over to 36% by mass. The predried lignite, kept in dedicated separate bunkers, was mixed with bituminous coal just before the coal mills. Computational fluid dynamic (CFD) simulation of a cofiring scenario of lignite with hard coal was also performed. Site measurements have proven that cofiring of a predried lignite is not detrimental to the boiler in terms of its overall efficiency, when compared with a corresponding reference case, with 100% of hard coal. Experiments demonstrated an improvement in the grindability that can be achieved during co-milling of lignite and hard coal in the same mill, for both wet and dry lignite. Moreover, performed tests delivered empirical evidence of the potential of lignite to decrease NOx emissions during cofiring, for both wet and dry lignite. Results of efficiency calculations and temperature measurements in the combustion chamber confirmed the need to predry lignite before cofiring. Performed measurements of temperature distribution in the combustion chamber confirmed trend that could be seen in the results of CFD. CFD simulations were performed for predried lignite and demonstrated flow patterns in the combustion chamber of the boiler, which could prove useful in case of any further improvements in the firing system. CFD simulations reached satisfactory agreement with the site measurements in terms of the prediction of emissions.

Comparison Analysis of Selected Nuclear Power Plants Supplied With Helium from High-Temperature Gas-Cooled Reactor

Abstract The article presents results of efficiency calculations for two 560 MW nuclear cycles with high-temperature gas-cooled reactor (HTGR). An assumption was made that systems of this type can be used in so-called marine nuclear power plants. The first analysed system is the nuclear steam power plant. For the steam cycle, the efficiency calculations were performed with the code DIAGAR, which is dedicated for analysing this type of systems. The other system is the power plant with gas turbine, in which the combustion chamber has been replaced with the HTGR. For this system, a number of calculations were also performed to assess its efficiency. Moreover, the article names factors in favour of floating nuclear power plants with HTGRs, which, due to passive safety systems, are exposed to much smaller risk of breakdown than other types of reactors which were in common use in the past. Along with safety aspects, it is also economic and social aspect which make the use of this type of systems advisable.

Application of ORC power station to increase electric power of gas compression ignition engine

The paper presents the calculation results of efficiency of the subcritical low temperature ORC power station powered by waste heat resulting from the process of cooling a stationary compression ignition engine. The source of heat to supply the ORC power station is the heat in a form of water jet cooling the engine at a temperature of 92°C, and the exhaust gas stream at a temperature of 420°C. The study considers three variants of systems with the ORC power stations with different ways of using heat source. The first variant assumes using just engine cooling water to power the ORC station. In the second variant the ORC system is powered solely by a heat flux from the combustion gases by means of an intermediary medium - thermal oil, while the third variant provides the simultaneous management of both heat fluxes to heat the water stream as a source of power supply to the ORC station. The calculations were made for the eight working media belonging both to groups of so-called dry media (R218, R1234yf, R227ea) and wet media (R32, R161, R152a, R134a, R22).

Efficiency assessment of wind farms in China using two-stage data envelopment analysis

China has been the world’s leader in wind power capacity due to the promotion of favorable policies. Given the rare research on the efficiency of China’s wind farms, this study analyzes the productive efficiency of 42 large-scale wind farms in China using a two-stage analysis. In the first stage, efficiency scores of wind farms are determined with data envelopment analysis and the sensitivity analysis is conducted to verify the robustness of efficiency calculation results. In the second stage, the Tobit regression is employed to explore the relationship between the efficiency scores and the environment variables that are beyond the control of wind farms. According to the results, all wind farms studied operate at an acceptable level. However, 50% of them overinvest in the installed capacity and about 48% have the electricity-saving potential. The most important factors affecting the efficiency of wind farms are the installed capacity and the wind power density. In addition, the age of the wind farm and the wind curtailment rate have a negative effect on productive efficiency, whereas the ownership of the wind farm has no significant effect. Findings from this study may be helpful for stakeholders in the wind industry to select wind power projects, optimize operational strategies and make related policies.

Plant Minimum Stable Load (Pmin) Test for Ilijan CCPP

This paper describes the test results of plant minimum stable load (Pmin) for Ilijan Power Plant. The test was conducted on May 13 through 14, 2015 to investigate the plant operating and equipment condition in accordance with "Ilijan Plant Performance Test Procedure on Plant Minimum Stable Load" [1]. This paper also contains the assessment of the impact of Pmin to plant operating parameters and possible technical operating issues when operating at lower loads and to recommend the safe minimum load operation of Ilijan per block. In addition, this paper describes the performance calculation results of efficiency and heat rate depending on the load level.

MIS and SIS solar cells on polycrystalline silicon

MIS- and SIS-structured solar cells are receiving much attention in the photovoltaic community. Apparently these cells could be a viable alternative to thermally diffused p-n junctions for use on thin film polycrystalline silicon substrates. In this paper we review MIS- and SIS-structured solar cells and the possible advantages of these structures for use with thin film polycrystalline silicon. The results of efficiency calculations are presented. We also consider the lifetime stability and fabrication techniques amenable to large-scale production. Finally the relative advantages and disadvantages of these cells and the results obtained are presented.

Large signal analysis of the multicavity klystron

The techniques developed to study large signal effects in the two-cavity klystron have been extended to determine performance of the multicavity tube. Bunching is computed as a function of excitation phase and amplitude at various gaps, tunnel lengths, beam diameter and density. Results of efficiency calculations taking into account velocity distribution within the bunch are discussed.