scholarly journals Technical and Ecological Analysis of Different Solutions of the Power Supply of a Marine Diesel Engine

2019 ◽  
Vol 26 (4) ◽  
pp. 127-134
Author(s):  
Rafał Krakowski

AbstractThe article contains provisions on the prevention of sea pollution by ships, including, inter alia, the International Convention for the Prevention of Pollution from Ships, developed in 1973 (MARPOL). The convention aims to protect the marine environment from oil and its derivatives. Special areas, where extraordinary measures have been taken to prevent sea pollution, due to the intensity of ship traffic and the greater threat of damage to the marine environment have also been presented. In the further part of the article, the applicability of various pro-ecological solutions, i.e. the use of catalysts, low-sulphur fuels, and in the case of using residual fuels – exhaust gas scrubbers were described. In the main part of the article, a technical and ecological analysis was made. In addition, difficulties resulting from the use of pro-ecological solutions were described. The costs of using low-sulphur fuel meeting the emission standards, installing the scrubber and modification of the natural gas combustion unit were compared with the assumption of ten years of passenger-car ferry sailing. Then the problems that individual solutions create were shown. In the final part of the article, alternatives to those described, i.e. the liquefied natural gas (LNG) power supply, electric and hydrogen drives were presented.

2019 ◽  
Vol 6 (2) ◽  
pp. 56-63
Author(s):  
L. D. Pylypiv ◽  
І. І. Maslanych

There are investigated the influence of operating pressures in the gas supply system on the level of such energy indicators as efficiency, gas flow and gas overrun by gas equipment in residential buildings. There is established a relationship between the values of operating pressures in the gas supply system and the gas consumption level of household appliances. The causes of insufficient pressure in the gas networks of settlements are analyzed in the article. There is also developed an algorithm for calculating the change in the efficiency of gas appliances depending on the operational parameters of the gas network. It has been found that the most efficient operation of gas appliances is observed at an overpressure at the inlet of gas appliances of about 1200 Pa.To ensure the required quality of natural gas combustion among consumers and minimize gas consumption there are justified the following measures in the article: coordinating a domestic regulatory framework for assessing the quality of natural gas with international norms and standards; improving the preparation of gas coming from local wells before supplying it to gas distribution networks; auditing low pressure gas pipelines and reconstructing areas affected by corrosion; ensuring standard gas pressure in the network for the normal operation of domestic gas appliances; stating quality indicators of natural gas combustion by gas sales organizations.


2002 ◽  
Vol 125 (1) ◽  
pp. 40-45 ◽  
Author(s):  
K. P. Vanoverberghe ◽  
E. V. Van den Bulck ◽  
M. J. Tummers ◽  
W. A. Hu¨bner

Five different flame states are identified in a compact combustion chamber that is fired by a 30 kW swirl-stabilized partially premixed natural gas burner working at atmospheric pressure. These flame states include a nozzle-attached tulip shaped flame, a nonattached torroidal-ring shaped flame (SSF) suitable for very low NOx emission in a gas turbine combustor and a Coanda flame (CSF) that clings to the bottom wall of the combustion chamber. Flame state transition is generated by changing the swirl number and by premixing the combustion air with 70% of the natural gas flow. The flame state transition pathways reveal strong hysteresis and bifurcation phenomena. The paper also presents major species concentrations, temperature and velocity profiles of the lifted flame state and the Coanda flame and discusses the mechanisms of flame transition and stabilization.


MTZ worldwide ◽  
2015 ◽  
Vol 76 (10) ◽  
pp. 30-35
Author(s):  
Bertold Hüchtebrock ◽  
José Geiger ◽  
Avnish Dhongde ◽  
Harsh Sankhla

2012 ◽  
Vol 26 (4) ◽  
pp. 2058-2067 ◽  
Author(s):  
Abolhasan Hashemi Sohi ◽  
Ali Eslami ◽  
Amir Sheikhi ◽  
Rahmat Sotudeh-Gharebagh

2018 ◽  
Vol 21 (5) ◽  
pp. 824-837 ◽  
Author(s):  
Jian Huang ◽  
Gordon McTaggart-Cowan ◽  
Sandeep Munshi

This article describes the application of a modified first-order conditional moment closure model used in conjunction with the trajectory-generated low-dimensional manifold method in large-eddy simulation of pilot ignited high-pressure direct injection natural gas combustion in a heavy-duty diesel engine. The article starts with a review of the intrinsic low-dimensional manifold method for reducing detailed chemistry and various formulations for the construction of such manifolds. It is followed by a brief review of the conditional moment closure method for modelling the interaction between turbulence and combustion chemistry. The high computational cost associated with the direct implementation of the basic conditional moment closure model was discussed. The article then describes the formulation of a modified approach to solve the conditional moment closure equation, whose reaction source terms for the conditional mass fractions for species were obtained by projecting the turbulent perturbation onto the reaction manifold. The main model assumptions were explained and the resulting limitations were discussed. A numerical experiment was conducted to examine the validity the model assumptions. The model was then implemented in a combustion computational fluid dynamics solver developed on an open-source computational fluid dynamics platform. Non-reactive jet simulations were first conducted and the results were compared to the experimental measurement from a high-pressure visualization chamber to verify that the jet penetration under engine relevant conditions was correctly predicted. The model was then used to simulate natural gas combustion in a heavy-duty diesel engine equipped with a high-pressure direct injection system. The simulation results were compared with the experimental measurement from a research engine to verify the accuracy of the model for both the combustion rate and engine-out emissions.


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