Simulating the Torsional Vibration Signal of Two-Stroke Marine Diesel Engine with Normal Firing and Mis-Firing

The article presented the modelling of torsional vibration signal of marine diesel engine, MAN B&W 6S46MC-C7, installed in general cargo ships 34000 DWT, built at Pha Rung Shipyard (Vietnam). The authors imitated the torsional vibration signal, based on the established signal modelling when diesel engine works normal firing and mis-firing state, according to the Class Regulation Rules for new building steel hull ships when calculating and measuring the torsional vibration of marine diesel propulsion shaft-line system. The authors used Matlab software to imitate the torsional vibration signals in the real time domain and then converted them into the frequency order by Fast Fourier Transform (FFT)

Concept for a LNG Gas Handling System for a Dual Fuel Engine

Pada saat sekarang ini, banyak kapal yang sudah menggunakan LNG sebagai bahan bakar utama mesin karena berdasarkan faktanya LNG tidak memiliki kandungan sulphur dan pada saat proses pembakaran LNG menghasilkan kandungan NOx yang rendah dibandingkan dengan heavy fuel oil dan marine diesel oil. LNG tidak hanya menghasilkan gas emisi yang rendah tetapi juga memiliki keuntungan ekonomis. Pada laboratorium mesin, jurusan maritime studies di Warnemunde, Germany, terdapat sebuah mesin type MAN 6L23/30A, dimana mode operasi mesin ini akan dirubah menjadi dual fuel engine. Oleh karena itu, pada thesis ini, penggunaan mesin berbahan bakar ganda akan dibandingkan ketika menggunakan natural gas dan marine diesel oil, kemudian menentukan komponen komponen yang dibutuhkan untuk sistem suplai bahan bakar gas. Dengan melakukan proses perhitungan, mesin MAN 6L23/30 A membutuhkan kapasitas natutal gas sebesar 12.908 m3 untuk kebutuhan 5 hari pada beban penuh. Sebuah konsep untuk sistem suplai bahan bakar gas akan dirancang dari storage tank sampai engine manifold. Germanischer Lloyd dan Project Guide dual fuel engine akan digunakan sebagai referensi untuk menghasilkan desain yang optimal dan memenuhi standard. ====================================================================== Nowadays, ships are using LNG as main engine fuel because based on the facts that LNG has no sulphur content, and its combustion process, LNG produces low NOx content compared to heavy fuel oil and marine diesel oil. LNG is not only produces low gas emission, but may have economic advantages. In the engine laboratory of maritime studies department in Warnemunde, Germany, there is a diesel engine type MAN 6L23/30 A, where the mode operation of these engine would be changed to dual fuel engine mode operation. Therefore, in this thesis, the use dual fuel engine will be compared where it will utilize natural gas and marine diesel oil and select the required components for fuel gas supply system. By conducting the process calculation, engine MAN 6L23/30 A requires the capacity natural gas of 12.908 m3 for 5 days at full load. A concept for LNG supply system would be arranged from storage tank until engine manifold. Germanischer Lloyd and Project Guide of dual fuel engine will be used as a guidelines to develop an optimal design and arrangement which comply with the regulation

Main Engine Selection Optimization Analysis of the Ship Caraka Jaya III Based on Engineering and Economy Cosiderations

Caraka Jaya III, as sister ships, built in Indonesia in the era 1990, devided into three building phases. Each phase had the different main engine. Especially for the second phase used the MAN B&W 5S26MC as main engine. After several years later, some of the engines were going to have the problems, especially for the pistons and its rings. The selected engine was not the only one that should be used. In accordance with selection the engine, the optimization procrdure offer best solution as compromise. Selecting the main engine is a complicated and time consuming task. The application of Analytic Hierarchy Process (AHP), one of the Multi Criteria Decision Making (MCDM), would promise a powerful tool for main engine selection as well as usual engineering design process. To select the candidate of the main engine it needs more criteria to obtain satisfactory solution. The criteria therefore are developed as pair wise coparison matrix leading to the mathematic solution. Analysis procedure is devided into three levels, namely, (1) criteria, (2) sub-criteria and (3) alternative of the selected engine. A consistency ratio needed as the acceptance criteria to check the solution of the pair wise comparison matrix. The final result obtained from multiplication of all matrixs on analysis, namely, SKL Diesel 8VD29/24AL- 0.149; MaK 9M20 – 0.190; Wartsila 9L20 – 0.088; Wartsila 6SW28 – 0.121; NIIGATA 8PA5L – 0.098; MAN B&W 5S26MC-0.354. According to the result, optimation solution will be MAN B&W 5S26MC or MaK 9M2

Fuel mass flow variation in direct injection diesel engine – influence on the change of the main engine operating parameters

A change in the main operating parameters of a high speed turbocharged direct injection diesel engine MAN D0826 LOH15 during the fuel mass flow variation has been analyzed. On the basis of two measurement sets, on two different engine rotational speeds, performed with standard diesel fuel, several operating parameters have been calculated: engine torque, effective power, excess air ratio, specific effective fuel consumption and heat released per engine process. The calculated parameters are presented for a wide engine operating range. In addition to measurement sets, several important parameters have been measured. Additional measured parameters have been lubrication oil temperature and exhaust gas temperature before and after the turbocharger turbine. The presented engine operating parameters allow deep insight into the analyzed diesel engine process

Engine performance and particulate matter speciation for compression ignition engines powered by a range of fossil and biofuels

Fuels: Non-renewable fossil fuels are the largest man-made contributor to global warming. Biofuel market share will increase, promoted by renewability, inherent lower net CO$_2$ emissions, and legislation. The environmental and human health impact of diesel exhaust emission particulate matter (PM) is a major concern. Fossil diesel PM aftertreatment systems exist. Near future fuel PM research and the evaluation of current aftertreatment technology, highlight a route for future development. Using a holistic approach this body of work studies the interdependence between the fuel, the CI engine and associated aftertreatment system. The overall objective of this thesis is the evaluation of current diesel aftertreatment using renewable near future fuels. Diesel blends with 1st and 2nd generation biodiesel fuels are viable. Carefully selected blends like B20G10 can make all round regulated emission improvements. Green additive dimethyl carbonate (DMC) enhances diesel combustion by oxygenation. Regulated emissions of THC, CO (>30% reduced) and PM (50% reduced) for 2% DMC in diesel. 1st generation biodiesel (RME) is widely available. Combustion produces significantly less solid PM than diesel (90% by mass >98% by number, for all fuels. For synthetically produced 2nd generation gas to liquid (GTL) fuels there are potentially DPF regeneration implications. Current aftertreatment solutions are as effective for bio alternatives as they are for fossil diesel. Biodiesels, green additives and aftertreatment are effective clean emissions improvements, until the promise of true zero emission vehicles is realised

Advanced Low-Floor Vehicle (ALFV) Specification Research

This report details the results of research on market comparison, operational cost efficiencies, and prototype tests conducted on a novel design for an Advanced Low Floor Vehicle (ALFV), flex-route transit bus. Section I describes how the need for such a bus arises from a combination of diminishing transit funding from the federal government and demographic and transportation factors. Section II describes the unique features of this bus design that render it suitable for rural and urban operation, including improved transit passenger and wheelchair accessibility, reduced maintenance, structural design features, safety provisions, and the technical specifications of this design. Section III details the potential differences in capital and operational costs of procuring and operating this bus in a fleet. Potential cost reductions due to the long-life vehicle concept, maneuverability, operational savings (from APTA Bus Roadeo tests), and reserve fleet savings are explored. Section IV refers to the Federal Transit Administration (FTA) new model bus tests (“Altoona Testing”). However, at the this time, the Altoona Bus Test Report for these tests is not yet released by the bus manufacturer, Ride Solution, Inc., as is its right under the Bus Testing Regulation. The report must be released to the public before this bus can be purchased by a transit agency using FTA funds. In addition to the standard Altoona Bus Test, additional research was conducted to determine the turning ability, suspension travel, ramp travel index, field of view for the driver, compliance to Americans with Disabilities Act (ADA) requirements, and timed assessment of wheelchair securement. Section IV also presents the results of these tests. Section V presents results from a market comparison that included the buses in this mid-size category that were tested at Altoona and are expected to be available for FTA grantees to purchase. The specifications and performance of the ALFV bus are compared with these buses. Section VI presents a flex-route utilization plan, and Section VII provides the results from a survey of transit professionals about their interest in the features of this bus design. Section VIII gives Ride Solution’s experience in developing the concept for ALFV. Conclusions of this report are presented in Section IX, followed by the references and appendices

Biofuel as an alternative shipping fuel : technological, environmental and economic assessment

© Royal Society of Chemistry 2019Fossil derived fuels available for application within the maritime sector have been dominated by heavy fuel oil (HFO), which is conventionally used in low speed (main) engines, and more refined fuels such as marine diesel oil (MDO), which is consumed in fast or medium speed engines. However, increasing fuel costs and regulatory pressure such as the restrictions placed on sulphur content have increased interest in the use of alternative fuels. A number of alternative fuels have been identified and may be viable for use within the maritime sector including straight vegetable oil (SVO) as an alternative to HFO in low speed engines, biodiesel to replace MDO/MGO in low to medium speed engines and bio-liquefied natural gas (bio-LNG) in gas engines using LNG. The potential sources of biomass feedstocks, conversion pathways and technologies are identified. The key parameters limiting their potential application are examined, in particular, availability, technological development, technical integration, and operational consequences. A proposed solution to overcome these limitations is recommended. The effective implementation of these strategies will enable the more widespread use of biofuels in marine applications, significantly reducing emissions from ships and improving global air quality and also protecting the ecological environment.Peer reviewe