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1
Content available Studies on the effects of cold starts of the ship main engine
Adamkiewicz Andrzej, Fydrych Janusz, Drzewieniecki Jan
Polish Maritime Research
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2022
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nr 3
109--118
EN
This article presents the influence of various ship’s operational conditions occurring during manoeuvres related to entering and leaving the ports and mooring operations. Frequent starts and stops of the ship’s propulsion unit are then required, which affect the variability of the energetic loads of the ship’s power plant, causing accelerated, non-design wear of the ship’s main propulsion engine. The effects of cold start-ups of the main ship engine are the subject of this study. Conditions of the engine inlet valve damage process are discussed. The physics of the degradation process leading to air inlet valve damage was considered. Laboratory tests of structure continuity and their results are discussed, and the valve material defects were excluded as the cause of the damage. The causes of repeated damage to the inlet air valves were identified. The effectiveness of the performed corrective measures was confirmed by a documented control test of the engine start-up. The article is a utilitarian premise for the requirements of the Classification Society.
2
Content available An attempt at applying machine learning in diagnosing marine ship engine turbochargers
Adamkiewicz Andrzej, Nikończuk Piotr
Eksploatacja i Niezawodność
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2022
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Vol. 24, no. 4
795--804
EN
The article presents a diagnosis of turbochargers in the supercharging systems of marine engines in terms of maintenance decisions. The efficiency of turbocharger rotating machines was defined. The operating parameters of turbocharging systems used to monitor the correct operation and diagnose turbochargers were identified. A parametric diagnostic test was performed. Relationships between parameters for use in machine learning were selected. Their credibility was confirmed by the results of the parametric test of the turbocharger system and the main engine, verified by the coefficient of determination. A particularly good fit of the describing functions was confirmed. As determinants of the technical condition of a turbocharger, the relationship between the rotational speed of the engine shaft, the turbocharger rotor assembly and the charging air pressure was assumed. In the process of machine learning, relationships were created between the rotational speed of the engine shaft and the boost pressure, and the indicator of the need for maintenance. The accuracy of the maintenance decisions was confirmed by trends in changes in the efficiency of compressors.
3
Content available Determination of the operating parameters of steam jet injectors for a main boiler’s regenerative feedwater system
Adamkiewicz Andrzej, Grzesiak Szymon
Zeszyty Naukowe Akademii Morskiej w Szczecinie
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2019
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nr 60 (132)
171--176
EN
Due to the development of alternative propulsion systems, there is a need for LNG tanker turbine propulsion plants to regain their competitiveness. Previous research revealed effective methods to increase the thermal efficiency of the steam cycle based on quality assessment, and it was proposed that the latent heat of the main turbine exhaust steam could be recovered. Research was carried out for the steam cycle using regenerative heat exchangers fed by steam jet injectors. In this paper, an algorithm to determine the operating parameters of steam jet injectors, and the calculation results for different drive steam parameters are presented. The obtained results will be used as input parameters for further heat balance calculations of the proposed regenerative steam cycles.
4
Content available Operational verification of a ship main power system element choice : case study
Adamkiewicz Andrzej
Journal of KONES
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2019
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Vol. 26, No. 4
7--14
EN
The article refers to results and conclusions on post-emergency repairs of a turbo-charging system of a DEUTZ engine of the SBV 8M 628 type of 1715 kW – the main power unit of a cement carrier. The failure of the turbocharger led to severing of a part of the exhaust outlet valve head. In order to determine the cause of the turbocharger fault, parametric identification of the reference state of the turbocharging system interacting with the ship main power engine has been carried out. The post-emergency servicing of the turbocharger comprised mounting a new blade rim of expansive instruments of smaller capacity than the so far used. Control measurement results of the power system after the replacement of the turbocharger turbine nozzle have been presented. Limitations of correct engine operation have been noted in the range of maximum load with continuous power (MCR). A range of corrective maintenance servicing of fuel equipment has been presented. Using the values of measured torque at the propeller shaft, incorrect interaction between the shaft and the main engine has been noted. A new propeller, adequate to the design operational parameters of the engine characteristics, has been chosen and mounted. The correctness of turbine expansive instrument replacement has been verified by correct interaction between the elements of the power system: propeller – main engine – turbocharging system. Thus, a wider range of economically acceptable ship operation has been obtained.
5
Content available Studies on resistance to erosion of nickel and its alloys to be used in elements of fluid - flow machines
Waliszyn Aleksandr, Adamkiewicz Andrzej
Eksploatacja i Niezawodność
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2019
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Vol. 21, no. 4
692--696
EN
The article presents results of studies on metal resistance to erosive damage taking place under the influence of hydraulic cavitation. On the basis of earlier research, a hypothesis on fatigue character of erosive wear and a dependence of metal resistance to erosive damage on its crystalline lattice structure has been assumed. To verify this hypothesis, metals with different crystalline lattice structures like steel 45 (flat-centred structure), nickel 200/201 and nickel alloy Monel 400 (hexagonal structure) have been tested at a cavitation-strike stand. Results obtained there confirmed the assumed hypothesis, at the same time justifying the use of nickel protective coatings in fluid-flow machines.
PL
W artykule przedstawiono wyniki badań odporności metali na uszkodzenia erozyjne zachodzące pod wpływem kawitacji hydraulicznej. Na podstawie wyników wcześniejszych badań, przyjęto hipotezę o zmęczeniowym charakterze zużycia erozyjnego oraz zależności odporności metali na zniszczenia erozyjne od struktury ich sieci krystalicznej. Dla potwierdzenia przyjętej hipotezy na stanowisku kawitacyjno-udarowym sprawdzono metale z różnymi sieciami krystalicznymi: stal 45 (sieć płasko centralna), nikiel 200/201 oraz stop niklu Monel 400 (sieć heksagonalna). Otrzymane wyniki badań potwierdziły przyjętą hipotezę, wskazując tym samym na zasadność stosowania niklowych powłok ochronnych w maszynach przepływowych.
6
Content available Waste heat recovery from the air preparation room in a paint shop
Adamkiewicz Andrzej, Nikończuk Piotr
Archives of Thermodynamics
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2019
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Vol. 40, no 3
229--241
EN
The policy of sustainable development seeks to improve energy efficiency of industrial equipment. Efforts to improve energy efficiency also apply to the paint shops, where the recovery of waste heat is sought. The main source of a large amount of low-temperature waste heat in the paint shop is the spray booth. The second place where a large amount of low temperature waste heat is released is the room where the compressed air is prepared. Low energy efficiency of air compressors requires a large electric power supply. As a result, the emitted large heat fluxes become waste energy of the technological process. Heat is equivalent to up to 93% of the electric power supplied in the air compression process. There are solutions for recovering heat from compressors coming from the oil cooling water, but then the waste heat from the cooling of the compressed air and from the electric motor is released into air in the room. A method for recovering low-temperature waste heat from the air preparation room by means of an air-source heat pump has been proposed. An energy balance of the air compression and dehumidification process for the paint shop was made. A Matlab’s built-in numerical model includes air compressor and dehumidifier, heat recovery and accumulation for the purposes of use in the spray booth. A simulation experiment was carried out on the effectiveness of heat recovery from the air preparation room. The use of combined energy management in paint shops was proposed.
7
Content available Identification of waste heat energy sources of a conventional steam propulsion plant of an LNG carrier
Adamkiewicz Andrzej, Grzesiak Szymon
Archives of Thermodynamics
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2019
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Vol. 40, no 3
195--210
EN
This paper presents the origins of marine steam turbine application on liquefied natural gas carriers. An analysis of alternative propulsion plant trends has been made. The more efficient ones with marine diesel engines gradually began to replace the less efficient plants. However, because of many advantages of the steam turbine, further development research is in progress in order to achieve comparable thermal efficiency. Research has been carried out in order to achieve higher thermal efficiency throughout increasing operational parameters of superheated steam before the turbine unit; improving its efficiency to bring it nearer to the ideal Carnot cycle by applying a reheating system of steam and multi stage regenerative boiler feed water heating. Furthermore, heat losses of the system are reduced by: improving the design of turbine blades, application of turbine casing and bearing cooling, as well as reduction in steam flow resistance in pipe work and maneuvering valves. The article identifies waste energy sources using the energy balance of a steam turbine propulsion plant applied on the liquefied natural gas carrier which was made out basing on results of a passive operation experiment, using the measured and calculated values from behavioral equations for the zero-dimensional model. Thermodynamic functions of state of waste heat fluxes have been identified in terms of their capability to be converted into usable energy fluxes. Thus, new ways of increasing the efficiency of energy conversion of a steam turbine propulsion plant have been addressed.
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