scholarly journals Methodology for determining the elemental composition, as well as energy and ignition properties of the low-sulfur marine fuels

2021 ◽  
Author(s):  
Zbigniew Korczewski

The key metrological issue of substance and energy balance in research engines is the precise determination of the ele-mental composition of the applied fuel and its net calorific value. This makes it possible to calculate the amount of heat brought with the fuel into the combustion chamber, as well as the amount and gas composition of the exhaust. However, to fully assess the energy quality of the fuel used, its ignition properties should also be estimated. They determine the combustion kinetics and, consequently, the course of gas pressure alterations and heat release in the cylinder, which have a direct impact on the indicated power and thermal efficiency of the engine. This article presents the methodology for carrying out this type of laboratory tests and their representative results con-cerning six different low-sulfur marine fuels used to feed marine engines at present. The considerations focus mainly on measurement technology, as well as the measuring apparatus applied today. Additionally some existing metrological difficulties that might be met were shortly described. The laboratory tests in question stand for the first stage of the program of testing a new kind of low-sulfur marine fuels in real operating conditions of a diesel engine, which was carried out at the Department of Ship Power Plants of the Gdańsk University of Technology.

2019 ◽  
Vol 178 (3) ◽  
pp. 15-19
Author(s):  
Zbigniew KORCZEWSKI

Within the article an issues of implementing the new kinds of marine diesel fuels into ships’ operation was described taking into ac-count restrictions on the permissible sulphur content introduced by the International Maritime Organization. This is a new situation for ship owners and fuel producers, which forces the necessity to carry out laboratory research tests on especially adapted engine stands. How to elaborate the method enabling quality assessment of the self-ignition engine performance, considered in three categories: ener-gy, emission and reliability, represents the key issue of the organization of such research. In the field of energy research, it is necessary to know the thermal efficiency of the engine as the basic comparative parameter applied in diagnostic analyzes and syntheses of sequen-tially tested marine diesel fuels. This type of scientific research has been worked out for two years in the Department of Marine and Land Power Plants of the Gdańsk University of Technology, as a part of the statutory activities conducted in cooperation with the Regional Fund for Environmental Protection in Gdansk and the LOTOS Group oil company. This article presents the algorithm and results of thermal efficiency calculations of the Farymann Diesel D10 test engine in the con-ditions of feeding with various low-sulfur marine diesel fuels: distillation and residual fuels. This parameters stands for one of ten diag-nostic measures of the ranking of energy and emission quality of newly manufactured marine diesel fuels being built at the Department.


2021 ◽  
Vol 10 (2) ◽  
pp. 021-027

Sawdust is often used as fuel for basic domestic needs like cooking, heating etc, with the application of the right technological procedure, the chemical energy in sawdust can be converted to electrical energy. sawdust is a usually a waste from timber processing industries and can pollute the environment if not properly disposed or utilized. Electricity can be generated from sawdust directly and sawdust can be processed into other products such as sawdust briquettes, pyrolysis oil, bioethanol and producer gas which can all be used to produce electricity using either a coal based thermal plant, oil based thermal plant and gas depending on the most suitable and efficient. As the calorific value of sawdust is dependent on the moisture content of the wood and the type of wood used, hence average calorific value of sawdust was used for this research work. In this study, the heat contents of sawdust and its various products were considered as fuels for divers power plants that is most suitable accordingly. This paper uses mathematical analysis to determine the amount of electrical energy produced from sawdust and it’s products. Sawdust briquettes was found to be the most efficient in terms of output power when a coal based thermal plant is utilized, the next being the utilization of a plain sawdust as fuel for a coal based thermal plant, the most optimal for the generation of electrical energy among the derivative of sawdust was pyrolysis oil being used as fuel in an oil based thermal plant.


Author(s):  
D. Goyal ◽  
A. H. King

TEM images of cracks have been found to give rise to a moiré fringe type of contrast. It is apparent that the moire fringe contrast is observed because of the presence of a fault in a perfect crystal, and is characteristic of the fault geometry and the diffracting conditions in the TEM. Various studies have reported that the moire fringe contrast observed due to the presence of a crack in an otherwise perfect crystal is distinctive of the mode of crack. This paper describes a technique to study the geometry and mode of the cracks by comparing the images they produce in the TEM because of the effect that their displacement fields have on the diffraction of electrons by the crystal (containing a crack) with the corresponding theoretical images. In order to formulate a means of matching experimental images with theoretical ones, displacement fields of dislocations present (if any) in the vicinity of the crack are not considered, only the effect of the displacement field of the crack is considered.The theoretical images are obtained using a computer program based on the two beam approximation of the dynamical theory of diffraction contrast for an imperfect crystal. The procedures for the determination of the various parameters involved in these computations have been well documented. There are three basic modes of crack. Preliminary studies were carried out considering the simplest form of crack geometries, i. e., mode I, II, III and the mixed modes, with orthogonal crack geometries. It was found that the contrast obtained from each mode is very distinct. The effect of variation of operating conditions such as diffracting vector (), the deviation parameter (ω), the electron beam direction () and the displacement vector were studied. It has been found that any small change in the above parameters can result in a drastic change in the contrast. The most important parameter for the matching of the theoretical and the experimental images was found to be the determination of the geometry of the crack under consideration. In order to be able to simulate the crack image shown in Figure 1, the crack geometry was modified from a orthogonal geometry to one with a crack tip inclined to the original crack front. The variation in the crack tip direction resulted in the variation of the displacement vector also. Figure 1 is a cross-sectional micrograph of a silicon wafer with a chromium film on top, showing a crack in the silicon.


TAPPI Journal ◽  
2014 ◽  
Vol 13 (8) ◽  
pp. 65-78 ◽  
Author(s):  
W.B.A. (SANDY) SHARP ◽  
W.J. JIM FREDERICK ◽  
JAMES R. KEISER ◽  
DOUGLAS L. SINGBEIL

The efficiencies of biomass-fueled power plants are much lower than those of coal-fueled plants because they restrict their exit steam temperatures to inhibit fireside corrosion of superheater tubes. However, restricting the temperature of a given mass of steam produced by a biomass boiler decreases the amount of power that can be generated from this steam in the turbine generator. This paper examines the relationship between the temperature of superheated steam produced by a boiler and the quantity of power that it can generate. The thermodynamic basis for this relationship is presented, and the value of the additional power that could be generated by operating with higher superheated steam temperatures is estimated. Calculations are presented for five plants that produce both steam and power. Two are powered by black liquor recovery boilers and three by wood-fired boilers. Steam generation parameters for these plants were supplied by industrial partners. Calculations using thermodynamics-based plant simulation software show that the value of the increased power that could be generated in these units by increasing superheated steam temperatures 100°C above current operating conditions ranges between US$2,410,000 and US$11,180,000 per year. The costs and benefits of achieving higher superheated steam conditions in an individual boiler depend on local plant conditions and the price of power. However, the magnitude of the increased power that can be generated by increasing superheated steam temperatures is so great that it appears to justify the cost of corrosion-mitigation methods such as installing corrosion-resistant materials costing far more than current superheater alloys; redesigning biomassfueled boilers to remove the superheater from the flue gas path; or adding chemicals to remove corrosive constituents from the flue gas. The most economic pathways to higher steam temperatures will very likely involve combinations of these methods. Particularly attractive approaches include installing more corrosion-resistant alloys in the hottest superheater locations, and relocating the superheater from the flue gas path to an externally-fired location or to the loop seal of a circulating fluidized bed boiler.


2020 ◽  
Vol 2 (2) ◽  
pp. 08-15
Author(s):  
Rahma Triyana ◽  
Salmi Salmi

Malaria is one of the health problems in Indonesia, especially West Sumatra. Determination of the description of Malaria disease in an area is needed to determine the spread and severity of the disease. This study aims to determine the frequency distribution according to age, sex and place of residence, description of the types of Plasmodium causes of Malaria and hematological features in Malaria patients at Siti Rahmah Padang Hospital in 2018. This type of research is a descriptive observational study with an approach or design cross section (cross sectional). The frequency distribution of Malaria sufferers in Siti Rahmah Padang Hospital in 2018 according to the highest age was in the age group 21-30 years as many as 28 cases (36.8%), the highest sex among men was 46 (60.5%) and the highest number of residences was found in Koto Tangah sub-district there were 31 cases (40.8%). The type of Plasmodium found in Malaria cases in Siti Rahmah Padang Hospital in 2018 was P. vivax (73 cases (96.05%)) and P. falciparum (3 cases (3.95%)). The results of laboratory tests on Hb, hematocrit, platelet and leukocyte levels in Malaria positive patients in Siti Rahmah Padang Hospital in 2018 were in the normal range.


2020 ◽  
Vol 2 (2) ◽  
pp. 08-15
Author(s):  
Rahma Triyana Y ◽  
Salmi Salmi

Malaria is one of the health problems in Indonesia, especially West Sumatra. Determination of the description of Malaria disease in an area is needed to determine the spread and severity of the disease. This study aims to determine the frequency distribution according to age, sex and place of residence, description of the types of Plasmodium causes of Malaria and hematological features in Malaria patients at Siti Rahmah Padang Hospital in 2018. This type of research is a descriptive observational study with an approach or design cross section (cross sectional). The frequency distribution of Malaria sufferers in Siti Rahmah Padang Hospital in 2018 according to the highest age was in the age group 21-30 years as many as 28 cases (36.8%), the highest sex among men was 46 (60.5%) and the highest number of residences was found in Koto Tangah sub-district there were 31 cases (40.8%). The type of Plasmodium found in Malaria cases in Siti Rahmah Padang Hospital in 2018 was P. vivax (73 cases (96.05%)) and P. falciparum (3 cases (3.95%)). The results of laboratory tests on Hb, hematocrit, platelet and leukocyte levels in Malaria positive patients in Siti Rahmah Padang Hospital in 2018 were in the normal range.


Author(s):  
O. M. Salamov ◽  
F. F. Aliyev

The paper discusses the possibility of obtaining liquid and gaseous fuels from different types of biomass (BM) and combustible solid waste (CSW) of various origins. The available world reserves of traditional types of fuel are analyzed and a number of environmental shortcomings that created during their use are indicated. The tables present the data on the conditional calorific value (CCV) of the main traditional and alternative types of solid, liquid and gaseous fuels which compared with CCV of various types of BM and CSW. Possible methods for utilization of BM and CSW are analyzed, as well as the methods for converting them into alternative types of fuel, especially into combustible gases.Reliable information is given on the available oil and gas reserves in Azerbaijan. As a result of the research, it was revealed that the currently available oil reserves of Azerbaijan can completely dry out after 33.5 years, and gas reserves–after 117 years, without taking into account the growth rates of the exported part of these fuels to European countries. In order to fix this situation, first of all it is necessary to use as much as possible alternative and renewable energy sources, especially wind power plants (WPP) and solar photovoltaic energy sources (SFES) in the energy sector of the republic. Azerbaijan has large reserves of solar and wind energy. In addition, all regions of the country have large reserves of BM, and in the big cities, especially in industrial ones, there are CSW from which through pyrolysis and gasification is possible to obtain a high-quality combustible gas mixture, comprising: H2 + CO + CH4, with the least amount of harmful waste. The remains of the reaction of thermochemical decomposition of BM and CSW to combustible gases can also be used as mineral fertilizers in agriculture. The available and projected resources of Azerbaijan for the BM and the CSW are given, as well as their assumed energy intensity in the energy sector of the republic.Given the high energy intensity of the pyrolysis and gasification of the BM and CSW, at the present time for carrying out these reactions, the high-temperature solar installations with limited power are used as energy sources, and further preference is given to the use of WPP and SFES on industrial scale.


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