scholarly journals On the Necessity of Changes in the Strategy of Utilization Ship Boiler Technical Condition Maintenance in the Aspect of LNG Applied as Fuel

2017 ◽  
Vol 25 (1) ◽  
pp. 29-34
Author(s):  
Andrzej Adamkiewicz ◽  
Wojciech Zeńczak

Abstract Heavy oils (HFO fuels) used on ships play a part in degradation of technical condition of heat exchange surfaces of utilization boilers especially on the exhaust gas side. Presence of sulphur in these fuels is the main factor favouring degradation. The upper limit for sulphur content in the fuel used outside the SECA areas equal to 3.5% is currently in force, at least until the year 2020 or 2025. The recommended by classification societies overhauls of utilization boilers are, therefore characterized by a specially chosen strategy thanks to which it is possible to maintain their appropriate technical condition. The requirement to use fuels with low sulphur content (LSFO), which are significantly more expensive than MDO fuels, in the areas of controlled sulphur emissions also led to a further introduction of alternative fuels, such as methanol and above all liquefied natural gas (LNG), onto ships. That is especially valid for the ship owners whose vessels e.g. ferries sail mainly within SCECA This article analyses the consequences of the introduced fuel change on utilization boiler maintenance. A change in the technical condition maintenance strategy for utilization boilers has been suggested.

HAND ◽  
1980 ◽  
Vol os-12 (3) ◽  
pp. 231-234 ◽  
Author(s):  
Leslie Klenerman

Tourniquet pressure rather than prolonged ischaemia is the main factor responsible for nerve palsies. It is essential to check the accuracy of the gauge of a pneumatic tourniquet against a mercury manometer regularly, as the commonest cause of a tourniquet paralysis is a faulty gauge. With regard to ischaemia three hours should be regarded as the upper limit of safety.


2015 ◽  
Vol 22 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Zbigniew Korczewski

Abstract The article discusses the problem of diagnostic informativeness of exhaust gas temperature measurements in turbocharged marine internal combustion engines. Theoretical principles of the process of exhaust gas flow in turbocharger inlet channels are analysed in its dynamic and energetic aspects. Diagnostic parameters are defined which enable to formulate general evaluation of technical condition of the engine based on standard online measurements of the exhaust gas temperature. A proposal is made to extend the parametric methods of diagnosing workspaces in turbocharged marine engines by analysing time-histories of enthalpy changes of the exhaust gas flowing to the turbocompressor turbine. Such a time-history can be worked out based on dynamic measurements of the exhaust gas temperature, performed using a specially designed sheathed thermocouple. The first part of the article discusses possibilities to perform diagnostic inference about technical condition of a marine engine with pulse turbocharging system based on standard measurements of exhaust gas temperature in characteristic control cross-sections of its thermal and flow system. Selected metrological issues of online exhaust gas temperature measurements in those engines are discusses in detail, with special attention being focused on the observed disturbances and thermodynamic interpretation of the recorded measuring signal. Diagnostic informativeness of the exhaust gas temperature measurements performed in steady-state conditions of engine operation is analysed in the context of possible evaluations of technical condition of the engine workspaces, the injection system, and the fuel delivery process.


2015 ◽  
Vol 5 (1) ◽  
pp. 20-35
Author(s):  
Ineke Kesuma Ningsih ◽  
Fitri Electrika D. Surawan ◽  
Zulman Efendi

The purpose of this research was to determine the percentage of each type of ‘roti manis’ physical damage, to identify factors causing the damages, and to determine whether the percentage amount of damage was whithin the business control limit. Types of damage observed were broken, too small in size, in appropriate form, over heated or burned.  Observation was conducted during 16 working days (one month) at Barokah Bakery in Lahat.  Result of the research showed that the broken damage was 1,31%; the too small in size was 1,1%; the unacceptable form was 0,98%; and no damage of over heat. Based on the causal effect analysis, it was found that the main factor causing ‘roti manis’s damages was caused by process inadequately. Result of diagram control analysis showed that the overall average damage was 3,4% with the upper limit was 5,2% and the lower limit was 1,6%. The percentage of the damage was considered high but it was within the company control limit of 2-4%


2019 ◽  
pp. 20-24
Author(s):  
Максим Андрійович Пирисунько ◽  
Роман Миколайович Радченко ◽  
Андрій Адольфович Андреєв ◽  
Вікторія Сергіївна Корнієнко

The problem of air basin pollution of the World Ocean with harmful emissions from the exhaust gases of marine diesel engines is primarily associated with the creation of highly efficient technologies for the neutralization of nitrogen oxides NOx on exhaust gases from a diesel engine. Emissions of harmful substances from the combustion of marine fuels are limited by international atmospheric protection programs and the requirements of the International Maritime Organization (IMO). The requirements relate to almost all groups of harmful emissions in marine engines and the more stringent of them are primarily related to nitrogen oxides NOx and sulfur oxides SOx. To reduce harmful emissions from exhaust gases into the environment, scientists and world engine leaders use and suggest various methods for reducing the content of harmful substances in exhaust gases. The implementation of new standards in the areas of further improvement of the working process, the use of alternative fuels, fuel, and air additives, as well as selective catalytic reduction systems do not preclude further development of scientific research in the field of exhaust gas cleaning. One of the promising ways in environmentalizing marine internal combustion engines is the neutralization of harmful substances in exhaust gases through particular gas recirculation (EGR-technology). However, the use of such techniques conflicts with the engine's energy efficiency. In the work presented, the scheme-design solution of the exhaust gas recirculation system with using the heat of recirculation gases by an ejector refrigeration machine for cooling the air at the intake of ship's main engine is proposed. The effect of using the heat of recirculation gases for cooling the air at the intake of the engine is analyzed taking into account the changing climatic conditions for a particular vessel's route line. It is shown that the use of an ejector refrigeration machine reduces the air temperature at the entrance of the main engine by 5…15 ° С, which reduces the specific fuel consumption. This reduces emissions of harmful substances when the engine is running with recirculation of gases.


2021 ◽  
Vol 12 (4) ◽  
pp. 23-40
Author(s):  
Naresh Kumar Konada ◽  
K.N.S. Suma ◽  
B.B. Ashok Kumar

Increase in energy demand, stringent emission norms and depletion of oil resources led to the discovery of alternative fuels forinternal combustion engines. Many alternative fuels like alcohols, petroleum gas, and compressed natural gas have been alreadycommercialized in the transport sector. In the present work, Pongomia oil and Neem oil are blended with diesel and used as analternate fuel for CI engines. The Pongomia oil and Neem oil can be converted into bio diesel using a chemical process of trans- esterification.Different proportions of fuel blends have been produced by the process of blending bio diesel consisting of 10%, 15%, 20%, 25%, and 30% (B10, B15, B20, B25, B30). The fuel properties of each blend are determined. The load test along with smoke and exhaust gas analysis of 4- Stroke Diesel engine using the blends of Pongomia oil and Neem oil with diesel are done in this study. The performance parameters of an engine are calculated for different blends. The sustainability of using alternate fuels in Diesel engines, especially the potential use of Pongomia oil and Neem oil as biodiesel have been brought to the fore through this work and suitable blends of bio diesel is suggested from the results. Keywords: 4-Stroke Diesel Engine, Pongomia and Neem oil Bo diesel, Performance, Smoke and exhaust gas analysis.


2012 ◽  
Vol 17 (1) ◽  
pp. 18
Author(s):  
Indartono Indartono

Indartono, in paper use of alternative fuel gas for a motor vehicle fuel oil explain that in many ways energy efficiency can also be more than just preservation. Energy efficiency is an attempt to reduce the use of petroleum materials and the selection of alternative fuels. Improved energy efficiency is also an environmental demands, because it can reduce air pollution, acid rain control the incidence and protect the earth from global warming, which may occur due to buildup of carbon dioxide in the atmosphere. One of the alternative fuel is CNG. In motor vehicles, CNG usage advantages include lower price, the exhaust gas is cleaner burning results and the potential source is still very large. Keywords: energy efficiency, fuel, CNG


2018 ◽  
Vol 7 (4.36) ◽  
pp. 920
Author(s):  
Byshov N.V ◽  
Bachurin A.N ◽  
Bogdanchikov I.Yu ◽  
Oleynik D.O ◽  
Yakunin Yu.V. ◽  
...  

The aim of the article is to develop a method and a device for reducing the toxicity of exhaust gases of diesel engines and reducing noise taking into account the current mode of operation of the engine. This is done with the help of installing a liquid catalyst (LC) into the exhaust system, ensuring the processes of trapping, chemical bonding and neutralization of toxic components and soot particles in the aerosol chamber while the vortex flow is being processed by a neutralizing solution supplied under pressure. Then the flow is divided into phases and toxic components and soot are separated in the centrifugal swirl drop separator (SDS).The developed and tested design of an exhaust gas cleaning device installed instead of the standard D-120 engine exhaust system and an automated cleaning process control system make it possible to reduce the toxicity of exhaust gases (EG): nitrogen oxides by 40 %, hydrocarbons by 43 % and soot by 70 %. The noise level of its work in enclosed spaces was reduced by 16–22 %. The device also had low gas-dynamic resistance.The investigation methodology is based on the use of modern methods and measuring devices. Exhaust gas tester META “Autotest CO – CH – CO2 – O2 – λ – NOx” was used to measure the toxicity of exhaust gases. To measure smoking at the exhaust of the diesel engine, the opacity meter META-01MP was used. The gas flow velocity was measured with ATT-1004 thermo-anemometer, the noise level of the tractor was recorded with noise and vibration meter VSHV–003–M2, and the fuel consumption with SIRT-1 meter.Theoretical studies were carried out on the basis of the laws of gas dynamics, the modern theory of statistical analysis, and experiment planning techniques. When developing an experimental LC model, dependencies were obtained, which allow to achieve the optimal design and technological parameters of the wet cleaning system for diesel exhaust gases.The optimization of the design parameters and the processing of experimental data were carried out with the help of modern software using the methods of mathematical statistics using computers.The current methods of reducing the toxicity of engines consist primarily in improving the design of engines, in order to influence the nature of the working process, the use of alternative fuels and additives, exhaust gas recirculation, as well as installing various types of exhaust gas catalytic systems. Measures related to the introduction of constructive changes in engines require some major restructuring of the industry, which is difficult to achieve in modern conditions. Alternative fuels have not yet been widely used in agriculture. Therefore, today the most effective and acceptable means of achieving environmental standards is the installation of various mobile catalysts in the exhaust system, as well as devices for trapping soot particles. The use of this exhaust gas cleaning system for diesel engines functioning in enclosed spaces can significantly improve the working conditions of the personnel and have a slight effect on the power and fuel-economic performance of the power unit, reducing the power of the D-120 engine of the T-30 tractor equipped with an upgraded exhaust system when taking external speed characteristics averaged 1.6 %, the torque was 1.5 % and the increase in specific fuel consumption was 1.8 %.In this paper we used materials from scientific publications indexed by bibliographic abstract databases of Scopus and Web of Science.   


2013 ◽  
Vol 832 ◽  
pp. 248-253
Author(s):  
B.S. Bidita ◽  
Suraya Abdul Rashid ◽  
Azni B. Idris ◽  
Mohamad Amran Mohd Salleh

Nanoemulsions are a class of nanomaterials which play an increasingly important role in commercial and environmental aspects. Water-in-diesel (W/D) nanoemulsion is considered one of the environmental friendly alternative fuels for reducing the emission pollution of internal combustion engine such as diesel engines. In this context, a study has been made to evaluate the combustion characteristics of W/D nanoemulsion fuel. A wide range of surfactant concentration (0.25% to 0.40% v/v) with varying amount of water percentage (0.5% to 0.8% v/v) was used in the preparation of W/D nanoemulsion fuel. The high energy emulsification method was applied to prepare W/D nanoemulsions. The combustion characteristics of W/D nanoemulsions are presented in terms of different formulating compositions. An engine test bed was used to combust the W/D nanoemulsions for measuring the exhaust emission concentrations such as CO, CO2 and NH3. A reduction in the concentrations of exhaust gas emissions was notified.


Author(s):  
Y. Tsujikawa ◽  
K. Kaneko ◽  
S. Fujii

In the course of the worldwide efforts to suppress the global warming, the saving energy becomes more important. Recently, the LNG (liquefied natural gas) terminals in our country have received more than 50 million tons of LNG per year. Therefore, the utilization of the cryogenic exergy in connection with the regasification of LNG gains more and more importance. The aim of this paper is the recovery of the energy consumed in liquefaction using the MGT (Mirror Gas Turbine), which is a kind of new combined cycle of a conventional gas turbine worked as a topping cycle and TG (inverted Brayton cycle) as a bottoming cycle. The optimum characteristics have been calculated and it is shown that this cycle is superior to the current-use gasification systems in employing seawater heats in terms of thermal efficiency and specific output. In the present cycle, the cold of LNG is used to cool the exhaust gas from a turbine of TG, and then the exergy of the liquefied natural gas is transformed to electric energy with a very high efficiency. The main feature of this new concept is the removal of an evaporation system using seawater.


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