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1

Marine diesel engine – a novel approach of indicated power determination and related uncertainty level

Kowalak P., Żmudzki S., Borkowski T.

Combustion Engines

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2017

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R. 56, nr 1

15--20

EN

A proposal of a new method for marine engine indicated power determination, based on direct piston position, instead of crankshaft angular position measurement, was presented. With the aid of bond graph theory, it was proved, that the new method is equivalent to conventional method. To verify hypothesis, that the new method has potential of determined indicated power uncertainty reduction, simulated calculations were carried out. Results of calculations for two marine diesel engines: medium-speed, four stroke and slowspeed two stroke type, at assumption of engine crankshaft constant speed, were compared with results obtained by a conventional method. Data, collected by means of a typical portable, industrial, digital indicator on engines in service, were used for simulation. The uncertainties of engines indicated power determined by means of two methods were analysed. The indicated power uncertainty, achieved for conventional method, was nearly twice higher than for new proposed method. Finally, uncertainty structure was analysed and evaluated for both: new and conventional method of engine indicated power determination.

2

Marine engine indicated power uncertainty determination

Kowalak P.

Combustion Engines

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2015

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R. 54, nr 2

3--13

EN

A proposal of marine engine indicated power uncertainty evaluation method was presented. The uncertainties of the indicated power definitional formula components were evaluated. Methods of uncertainty estimation for measurement carried out in industrial conditions were proposed. A new component called a phase shift angle, in modified formula for the piston kinetic was introduced. The indicated power uncertainty was divided into two calculable parts called uncertainty category I and uncertainty category II. The results of the uncertainties determined for two marine engines: trunk piston and cross-head type were presented. The influence of the individual component of indicated power formula for the overall indicated power uncertainty value was shown.

PL

Zaprezentowano propozycję metody oceny niepewności mocy indykowanej silnika okrętowego. Określono niepewności składników definicyjnego równania mocy indykowanej. Przedstawiono metody szacowania niepewności dla pomiarów przeprowadzonych w warunkach przemysłowych. W zmodyfikowanym równaniu ruchu tłoka wprowadzono nową wielkość fizyczną określoną jako kąt przesunięcia fazowego. Zaproponowano także podział niepewności mocy indykowanej na dwie obliczalne części, nazwane niepewnością rodzaju I oraz niepewnością rodzaju II. Przedstawiono wyniki niepewności wyznaczonych dla dwóch silników okrętowych: wodzikowego i bezwodzikowego. Zaprezentowano wpływ poszczególnych składników równania mocy indykowanej na wartość jej całkowitej niepewności.

3

Vessel main propulsion engine performance evaluation

Borkowski T., Kowalak P., Myśków J.

Journal of KONES

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2012

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Vol. 19, No. 2

53-60

EN

In general, the performance of a ship in service is different from that obtained on shipyard sea trial. Apart from any differences due to loading conditions, and for which due correction should be made, these differences arise principally from the weather, fouling and surface deterioration of the hull and propeller. The influence of the weather, both in terms of wind and sea conditions, is an extremely important factor in ship performance analysis. Consequently, the weather effects needs to be taken into account if a realistic evaluation is to be made. The primary role of the ship service analysis is a standard of performance data, under varying operational and environmental conditions. The resulting information, derived from this data, becomes the basis for operational and chartering decision. In addition, the part for the data records is to enable the analysis of trends of either the hull or machinery, from which the identification of potential failure scenarios and maintenance decisions can be derived. The traditional method of data collection is the deck and engine room log records, and this is the most commonly used method today. In terms of data processing and capabilities, this method of data collection is far from ultimate, since involves significant data distortion risk. Instrumentation errors are always a potential source of concern in performance analysis methods. Such errors are generally in the form of instrument drift or gross distortion of the reading. However, these can generally be detected by the use of trend analysis techniques. The procedure for the evaluation of the ship's service performance, that relies on proven methods of main propulsion engine service data analysis used and applied for container vessel - small feeder. The vessel is equipped with indirect main propulsion, driven by means of modern medium speed engine. The different approach demonstrated to achieve the reliable and accurate main engine performance. The difference in developed engine power has been found, that corresponds well to registered sea trial results and engine retrofitting reports done, in order to limit the effective power.

4

Energy efficiency design index of container vessel - operational approach

Borkowski T., Kasyk L., Kowalak P.

Journal of KONES

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2012

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Vol. 19, No. 4

93-100

EN

The ship "Energy Efficiency Design Index (EEDI)" has been formulated by the IMO Marine Environment Protection Committee (MEPC) as a measure of the CO2 emission performance of ships. The ship EEDI is calculated based on characteristics of the ship at build, incorporating parameters including ship capacity, engine power and fuel consumption. Shipping is responsible for CO2 discharge of approximately 3.3% global emission and despite being an energy-efficient transport means, compared with other transport modes, there are opportunities for increasing energy efficiency. The EEDI requires a minimum energy efficiency level (CO2 emissions) per capacity mile (e.g. tonne mile) for different ship type and size sectors. With the level being tightened over time, the EEDI will stimulate continued technical development of all the components influencing the energy efficiency of a ship. The paper presents an overview of EEDI calculation method for container vessels and results of experimental approach. The experimental process results through comprehensive analysis of operational data, from modern container vessel, equipped with direct main propulsion unit have been introduced. Ship operators have already been implementing energy efficiency operational measures and set goals for reducing the energy consumption of their fleet. Performance and savings are not always monitored and reported. However, it can be foreseen that such activity when is successfully promoted, reduction of CO2 emissions can be achieved.

5

Combustion pressure appraisal in marine diesel engine

Borkowski T., Kowalak P., Marcinek M., Bonisławski M.

Journal of KONES

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2011

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Vol. 18, No. 4

25-32

EN

The practical design of the marine engine multi in-cylinder pressure acquisition system has been presented. The system operational properties and measurement methodology is aimed the online marine diesel engine applications. The design of engine combustion pressure recording system is based on piezoelectric sensors set that comprises quartz pressure element and charge amplifier, mounted on the indicator pipes, equipped with valves. The required crank degree signal is obtained from shaft encoder that is installed on the test bed engine shaft-line (free end of the hydraulic break). The encoder's TDC dedicated reference pulse is able generate simultaneously at the cylinder 1 and 6 in TDC position. The accuracy of the static crankshaft position calibration was evaluated. Additionally, a complex timing system was developed for individual cylinder TDC and crankshaft positioning definition. Before real time data acquisition starts, the number of engine cycles is defined for recording and the first pulse of each crankshaft revolution is used as trigger signal, so that all instantaneous pressure and crank angle signals acquisition can be started at the identical crankshaft position. The method provides required numbers of combustion cycles to be measured for time domain averaging and off line processing.

6

Assessment of ship's engine effective power, fuel consumption and emission using the vessel speed

Borkowski T., Kasyk L., Kowalak P.

Journal of KONES

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2011

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Vol. 18, No. 2

31-39

EN

Currently, the Baltic Sea States suggests a proposal to designate the Baltic Sea as an Emission Control Area for nitrogen oxides, in accordance with Annex VI of MARPOL73/78. The emission would be estimated on the data produced by the AIS (Automatic Identification System) system that is compulsory for ships. Therefore, exhaust emission of the ships' can be computed using the actual speed and main propulsion shaft power. Mostly, main propulsion engines' exhaust emission is dependent to realistic performance and can be determined. The research plan has been prepared, aimed an evaluating the main propulsion engine performance and emissions. In cooperation with the ship owner, the experimental program onboard the container vessel, equipped with latest large bore, two-stroke, and slow speed MAN B&W electronic controlled engine was carried out. The records set of vessel speed and related engine shaft power, fuel consumption and exhaust emission for container vessel is formed. Taking into account; main engine performance, types of fuel and other input data, the emission factors were determined for ship sea service state. Main engine shaft power estimation and measurement setup, examples of main engine shaft power, the shaft power equation coefficients density, example of main engine service operation, fuel oil consumption group, the ship speed estimated form, example of main engine area operation influenced by weather conditions are presented in the paper.

7

The Angle Measurement Uncertainty Evaluation By Means Of Incremental Encoder

Kowalak P.

Journal of Polish CIMAC

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2009

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Vol. 4, no 2

121-128

EN

The application of incremental encoders in the marine engines field was briefly described. The problem of the angle measurement uncertainty evaluation by means of an incremental encoder was presented. A theoretical assumption of experiment was discussed and a project of an experimental test allowing statistical evaluation of angle measurement uncertainty was proposed. The uncertainty estimation of a type A as well as the type B according to ISO standards was carried out. The numerical values of the results were presented. The proposition of improvement of test bed for encoders examination was proposed.

8

In cylinder pressure assessment from marine diesel engine

Borkowski T., Kowalak P.

Journal of KONES

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2009

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Vol. 16, No. 3

39-46

EN

This paper explores the feasibility ofusing in-cylinderpressure-based variables in terms of certain class of errors, caused by indirect pressure measurement. Experimental direct in-cylinder measurement pressure setup was constructed, to make comparisons with standard indicator channel and indicator valve design. Zero-dimensional model was used for particular combustion system design. Subsequently, paper describes the application of a zero-dimensional combustion model for pressure signal analysis in cylinder head indicating passage of medium speed marine diesel engine. Recording of engine cylinder pressure development and its qualified evaluation is common aid for maintenance. Especially the outline of experimental test-bed, the injector nozzle equipped with piezoelectric pressure transducer, measurement system specification, B type uncertainty -mean angular speed characteristic, wavelet "denoising" setting and signals comparison, engine cylinder indicator model channel, cylinder pressure traces influenced by engine speed and load, cylinder pressure traces influenced by engine load and speed with two different indicator channel lengths, Indicated engine cylinder power in motoredmode of operation are presented in the paper.

9

Wykorzystanie inteligentnych przetworników pomiarowych w procesie dydaktycznym

Kowalak P.

Zeszyty Naukowe / Akademia Morska w Szczecinie

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2008

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nr 15 (87)

349-354

PL

Scharakteryzowano pojęcie przetwornika inteligentnego. Przedstawiono możliwosci prowadzenia zajęć dydaktycznych z wykorzystaniem przetworników zainstalowanych w stanowiskach laboratoryjnych Akademii Morskiej. Przedstawiono możliwości konfiguracji zdalnej i lokalnej przetworników oraz podano możliwości ich zastosowania w przemyśle i dydaktyce.

EN

Characterization of smart sensor concept. Presentation of educational opportunities of smart sensors installed in laboratory of Maritime Academy of Szczecin. Presentation of local and remote methods of configuration and calibration and their educational applications.

10

Experimental Determination Of Low Speed Diesel Engine Crankshaft Twisting

Kowalak P.

Journal of Polish CIMAC

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2008

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Vol. 3, no 2

9-13

EN

The exhaust gas emission control, together with the demand for specific fuel oil consumption reduction, poses a challenge for constructors. As a possible solution a very accurate fuel injection and combustion process control is considered. Such a control needs a precise timing and synchronization with every piston movement. The understanding of crankshaft deformation phenomena seems to be essential. In this work the experimental methodology of the crankshaft twist angle determination has been presented. The method is based on the cylinder pressure signal and an incremental encoder signal analysis. The presented results show the mean value of crankshaft twist angle under load. The momentary values are presented, too.

11

Speed irregularity characteristic of low speed, two-stroke marine diesel engine applied as vessel's main propulsion

Kowalak P.

Journal of KONES

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2008

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Vol. 15, No. 4

263-268

EN

The piston engine irregularity is a consequence of the uneven power supply from the engine units. As such, it contains valuable information about engines units working process. Unfortunately, it is strongly influenced by torsional vibration, resonance, and propeller behaviour. In order to better understand the speed irregularity phenomena the instantaneous speed was recorded and its characteristic against engine mean speed was developed. Some statistical parameters: standard error and deviation as well as variance were determined. The results were compared with propulsion plant torsional vibration. The presented results show that the irregularity of the long stroke engine's speed is strongly influenced by torsional vibration phenomena. The analyzed engine has a bared speed range 37-43 rpm. Exactly around that range, the speed irregularity reaches its maximum values of 18% of mean speed. The analysis can be considered as qualitative look into the phenomena. However even based on the presented analysis one can observe some practical inferences. The common type of electronic indicators is used to simplify the measurement by assuming that the shaft speed is equal in between the pickup pulses. In order to increase the accuracy of the indicated power determination the use of such instrument should be avoided in the speed range, which is a multiple number of the barred speed. Due to the fact that the shaft speed is irregular especially in the ranges where torsional resonance may occur the piston positioning (for example for TDC determination) purpose procedure should take it into account.

12

Marine diesel engine piston's instantaneous position experimental determination

Kowalak P.

Problemy Eksploatacji

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2007

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nr 3

113-120

PL

Przedstawiono eksperymentalne możliwości obserwacji ruchu tłoka poprzez skrzynię korbową silnika okrętowego. Wyznaczono charakterystyczne punkty położenia tłoka w czasie. opracowano metodę estymacji wystąpienia GMP tłoka na podstawie jego obserwowanych położeń. Zaproponowano model matematyczny umożliwiający szacowanie położenia dynamicznego GMP tłoka na podstawie obserwacji jego ruchu. Wykazano występowanie różnicy pomiędzy wystąpieniem GMP termodynamicznym, a GMP dynamicznym.

EN

The experimental possibility of piston movement observation through the crankcase has been presented. The characteristic piston positioning points in the time domain have been determined. The piston TDC estimation methodology based on observed positioning points has been developed. A mathematic model for piston TDC estimation has been proposed. The difference between thermodynamic and dynamic TDC has been detected and presented.

13

The dynamic TDC assigning on the marine four stroke engine's indication diagram

Kowalak P.

Journal of KONES

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2007

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Vol. 14, No. 2

259-266

EN

Determination of the internal combustion piston engine 's indicated power is a complex task. A number of difficulties lead to lots of solutions utilized to increase the accuracy of the result. This paper reports on the experiments concerned with a four stroke engine's piston dynamic position determination. Although the paper is mostly concerned with the piston's TDC definition, the experimental methodology can be utilized in the entire piston movement determination. A specially developed measuring assembly and its working principle utilized in the experiment have been presented too. It allows the acquiring of a set of time-position coordinates. Based on the coordinates, the mathematical algorithm for dynamic piston positioning can be developed. As the piston movement was being observed from the crankcase side, the methodology proved to be relatively cheap and easier for installation, compared to proximity sensors installed in the cylinder head. The advantage of optical sensors and light pipes being used was reduction of the explosion risk in oil mist environment inside the crank case.

14

Instantaneous piston speed measurement for marine diesel engine combustion monitoring

Kowalak P., Borkowski T.

Journal of KONES

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2006

|

Vol. 13, No. 2

215-223

EN

It is important that marine diesel engines run in their normal condition in order to maintain correct efficiency, low pollution and high reliability. The record of in-cylinder pressure pattern and its evaluation is one of the most powerful sources for experimental based analysis of internal combustion engines. In addition, collected data and calculated values expand the engine diagnostic system capabilities. From the other hand reliable calculation of mean indicated pressure and other performance data requires accurate measurement of cylinder pressures and detection of the crankshaft position. It is necessary to ensure correct synchronization of recorded pressure shape with crankshaft position. For this purpose magnetic pick-up to measure the rotational speed from flywheel is usually used as a source of sampling pulses. The instantaneous piston speed can be investigated using the linear movement sensor located inside the crankshaft box. For this purpose marine propulsion testing engine was equipped with optic fiber sensor to perform permanent piston position measurement. Test bed with examined engine is equipped additionally with: optoelectronic in-cylinder pressure transducer, magnetic pick-up to measure rotational speed from flywheel, optic fiber sensor to measure the rotational speed and angular increments from propeller shaft and strain gauge arrangement designed to provide effective torque measurement.

15

Możliwości eliminacji zakłóceń przy pomiarach ciśnień w komorze spalania silników okrętowych

Borkowski T., Kowalak P.

Zeszyty Naukowe / Akademia Morska w Szczecinie

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2005

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nr 5 (77)

111--120

PL

Potrzeby wprowadzenia systemów monitoringu procesu spalania, wszystkich układów cylindrowych silników okrętowych przez cały okres eksploatacji stymulują rozwój techniki elektronicznego indykowania. Dane z systemów monitoringu mają służyć zaawansowanej diagnostyce pracy silnika. Złożone przetwarzanie sygnałów pomiarowych wymaga zastosowania precyzyjnych i efektywnych elementów przeciwzakłóceniowych. W artykule przedstawiono aspekty zastosowania filtrów elektronicznych w pomiarze ciśnień w komorze spalania.

EN

In order to improve the reliability of the engine system, a new technology for engine control is needed. One of the methods used to meet this requirement is to develop a convenient and real-time measuring system. The equipment can be used in order to evaluate engine performance. Conventional calculations based on the pressure-volume diagram require a high-speed central processing unit (CPU) and a high accuracy measurement instrument. This paper presents some interference problems with combustion pressure measurement and analysis.

16

Eksploatacyjna metoda analizy rozkładu obciążeń użytecznych silników napędu głównego statku

Borkowski T., Kowalak P., Kijewska M.

Zeszyty Naukowe / Akademia Morska w Szczecinie

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2005

|

nr 5 (77)

121--130

PL

Okrętowe wolnoobrotowe silniki wysokoprężne stanowią zdecydowaną większość głównych napędów dla statków handlowych. Instalowane są one w najprostszych układach napędowych, gdzie silnik jest bezpośrednio połączony ze śrubą. Taki układ zapewnia najwyższą sprawność i najniższe z możliwych zużycie paliwa. Warunkiem uzyskania najlepszych rezultatów w tym zakresie jest utrzymywanie w czasie eksploatacji statku określonych zasad eksploatacji głównego napędu statku. W artykule przedstawiono uproszczoną metodę analizy istotnych wskaźników pracy głównego układu napędowego statku. Metoda może być stosowana w eksploatacji silników wyposażonych w standardowe urządzenia pomiarowe.

EN

The marine diesel engine today is the prime mover for ship propulsion. The most typical marine propulsion plant of modern merchant ships is a single, slow-speed turbocharged, two stroke diesel engine, directly coupled to the vessel's single, fixed or controllable pitch propeller. This configuration can provide high power outputs and improved fuel economy. The paper deals with basic ship propulsion factors used for fuel consumption calculations.

17

Emisja NOx przez silniki okrętowe - możliwości weryfikacji w eksploatacji

Borkowski T., Kowalak P.

Zeszyty Naukowe / Wyższa Szkoła Morska w Szczecinie

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2002

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nr 66

103-113

EN

In any program designed to achieve emissions reductions from internal combustion engines, the test procedures that are used to determine emissions levels are as important as the emissions standards that are implemented. Three duty cycles, designed by the ISO for propulsion marine diesel engines are employed. This paper discusses the testing issues specific to marine engines, supported by means of example.

PL

W każdym programie ukierunkowanym na redukcję emisji składników toksycznych spalin z silników tłokowych wykorzystuje się kontrolne procedury testowe, które są niezwykle istotne, tak jak ustanawiane ograniczenia emisji. Trzy cykle testowe sformułowane w normach ISO są przeznaczone dla okrętowych silników napędowych. Na podstawie podanego przykładu omówiono aspekty możliwości weryfikacji emisji NOx w eksploatacji.