This paper presents the results of previously carried out analyses regarding efficiency and criteria evaluation of various propulsion plants of modern LNG (Liquid Natural Gas) carriers. The results of previous identification and quality assessment of waste heat energy sources of a CST (Conventional Steam Turbine) plant are presente. In this paper the possibility of use a steam jet injector in order to recover the latent heat is analysed. Calculations were carried out for an injector equipped with a de Laval nozzle, determining the thermodynamic state parameters of the mixture of drive steam and sucked in steam as well as the steam on the outlet of the injector for the various ejection ratios. On the basis of the results of the injector calculation, the heat balance of a simple regenerative Clausius – Rankine steam cycle (with one regenerative heater – deaerator) was carried out. The degree of regeneration (increase of the thermal efficiency) for cycle using the regenerative injector was determined. Based on results the further research directions for complex plants using a steam jets are indicated.
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.
The increase of maritime international trade, especially of dangerous liquid cargos led to a significant increase of the number of sea-going ships. Their operation poses a real threat to the maritime environment both as a result of terminal events with transported dangerous liquid cargos and emissions of harmful products from fuels burnt by ship power systems. Because of those there is a need to undertake actions to prevent such occurrences using formal, legal and utilitarian tools. Philosophy of research methodology and rationalization of actions in compliance with international directives have been shown. The article presents the guidelines of the IMO Resolution MEPC 231(65) on preventing air pollution with carbon dioxide from ships. Design Energy Efficiency Index (EEDI) for a new ship was given as well as Energy Efficiency Operational Indicator (EEOI) determined for conventional ships after a completed voyage was defined and interpreted. A model of a Ship Energy Efficiency Management Plan (SEEMP) of a chosen ship has been constructed taking into account possible actions aimed at obtaining the highest power efficiency of the ship at sea voyage. Conclusions have been drawn and possible directions of further actions have been established.
Marine work conditions, differing from those on land, have been presented. The study has identified a multitude of factors generating physical and psychical effects on crew members, different cultural patterns and dangers which have to be overcome to reach the state when thinking of safety accompanies all performed activities. Creation of legislature and procedures and their observance have been presented as a basis for constructing safety culture and the sense of safety. Safety management, coordinated by ship owners, has been justified as activities to be realized on ships. It has been indicated in this study that building up safety culture among the members of the power plant crew of seafaring ships is the most important issue due to the fact that their work environment is unfriendly to humans and that there is a high fire risk in a ship power plant.
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.
The paper discusses the problem of maintenance of the marine steam turbogenerator sets used in power systems on VLCC type oil tankers. The analysis of operation, monitoring and applied diagnostic methods of a selected turbogenerator working in the AT series waste energy system produced by Mitsubishi is presented. The analysis focuses on the applied maintenance method and its credibility and effectiveness in terms of technical assessment. The results of the performed maintenance actions and applied operational procedures making use of technical diagnostics and supported by a wider range of measurement capabilities of external service are presented and evaluated. The range of the study includes the readiness, reliability and safety of the use of turbogenerators being the result of the maintenance performed in accordance with the applied strategy of operation.
The article justifies the application of gas fuels for supplying auxiliary ship boilers. It presents legal regulations on maritime environmental protection areas and their requirements which are in power. It shows the chronology of introduced limitations on sulphur and nitrogen dioxide emissions and thresholds of carbon dioxide emission reduction expressed by EEDI (Energy Efficiency Design Indicator) and EEOI (Energy Efficiency Operational Indicator). Ways to decrease the values of EEDI and EEOI in the ship energy effectiveness management have been shown. Consequences of replacing marine fuels with LNG for running auxiliary ship boilers have been considered thoroughly, taking into account ecological, constructional, operational, procedural and logistic limitations as well as economic consequences. The summary shows the influence of particular consequences of using LNG for running boilers on the methods of maintenance of auxiliary boilers.