Research on influence and demand of Miller cycle based on the coupling of marine low-speed engine and turbocharger

Author(s):  
Dawei Wang ◽  
Lei Shi ◽  
Heng Zhang ◽  
Xiaofeng Li ◽  
Yuehua Qian ◽  
...  
Keyword(s):  
Author(s):  
Thomas S. Knudsen ◽  
Ole Groene ◽  
Per Soerensen

The Norwegian shipowner Odfjell has had more than one year’s experience of operating a vessel powered by an MAN B&W 6L60MC/ME low-speed engine capable of operating by electronic valve control, without a camshaft. During that period, the engine has run in both conventional and camless modes. Valuable data has been collected on the impact of camless engine technology, on operating performance, and on operating costs. Odfjell has now ordered a 7-cylinder S50ME-C engine, featuring electronic operation, for installation on a 37,500 dwt chemical tanker newbuilding.


Author(s):  
Syed Adnan Qasim ◽  
Usman F. Chaudhri ◽  
M. Afzaal Malik ◽  
Riaz A. Mufti

In the normal high speed engine operation at small piston-to-bore radial clearance, elastohydrodynamic lubrication (EHL) of skirts and non-Newtonian lubricant behavior prevent adhesive wear, but in the initial engine start up, the large clearance, low speed and absence of EHL, cause start up wear. This study models 2-D upper convected Maxwell viscoelastic EHL of piston skirts at small radial clearance in a few initial low speed engine start up cycles by solving the Reynolds equation and using the inverse solution technique. The numerical analysis incorporate characteristic lubricant relaxation times and a perturbation method to predict and compare hydrodynamic and EHL pressures and film profiles. The effects of viscoelasticity on the lubricant characteristics, transverse eccentricities of piston, film thickness, and pressure fields in the hydrodynamic and EHL regimes are investigated. This study suggests that EHL film is formed at very small piston-to-bore radial clearance at low start up speed under assumed conditions to prevent start up wear as viscoelasticity produces a beneficial effect on piston skirts lubrication in the initial engine start up.


2021 ◽  
Vol 9 (3) ◽  
pp. 321
Author(s):  
Roman Varbanets ◽  
Oleksij Fomin ◽  
Václav Píštěk ◽  
Valentyn Klymenko ◽  
Dmytro Minchev ◽  
...  

The article presents the acoustic method of marine low-speed engine turbocharger parameter estimation under operating conditions when a prompt assessment of instantaneous turbocharger speed and rotor vibration level is required. The method lies in the analysis of the acoustic signal that is generated by the compressor of the turbocharger with the diesel engine running under load. The spectral analysis reveals that the compressor blades generate acoustic oscillations that are always present in the overall acoustic spectrum of the turbocharger regardless of its technical condition. The harmonic components corresponding to the blades can be detected in the spectrum using the limit method. The calculated instantaneous turbocharger speed makes it possible to analyze the main harmonic amplitude in the spectrum. The method presented in this paper helps eliminate discrete Fourier transform (DFT) spectral leakage so that the amplitude of the main harmonic can be estimated. Further analysis of the amplitude of the main harmonic allows for efficient estimation of the turbocharger rotor vibration level when in operation. The method can be practically applied by means of a smartphone or a computer that has the dedicated software installed. The proposed method lays the foundations for a permanent monitoring system of turbocharger speed and vibration in industrial and marine diesel engines.


2020 ◽  
pp. 30-35
Author(s):  
Андрій Миколайович Радченко ◽  
Дмитро Вікторович Коновалов ◽  
Іван Володимирович Калініченко ◽  
Чен Нінь ◽  
Хан Баочен

The efficiency of cooling the scavenge air of the main low-speed engine of the transport vessel during operation in the equatorial tropical latitudes is analyzed. The peculiarity of the tropical climate is the high relative humidity of the air at the same time its high temperatures and temperatures of seawater. The cooling of the scavenge air with an absorption lithium bromide chiller by transforming the scavenge air heat into the cold was investigated. With this, the potentially possible minimum temperature of the cooled air was determined considering the temperature of the cold water (coolant) from the absorption lithium bromide chiller and the temperature differences in the heat exchangers of the intermediate water circuit of cooling. Absorption lithium bromide chillers are characterized by high efficiency of transformation of waste heat into cold - high coefficients of performance. Circuit-design solution of three-stage cooling system of scavenging air of ship's main engine - in high-temperature (cogeneration) stage using the extracted heat of scavenging air to get cold with absorption chiller and traditional stage for cooling scavenge air by seawater and low-temperature cooling stage by absorption chiller. The effect of deeper cooling of the scavenge air was determined in comparison with the cooling of the scavenge air with seawater, taking into account the changing climatic conditions during the route of the vessel. It is shown that due to the high efficiency of heat transformation in absorption chillers (high coefficients of performance 0.7…0.8), there is a significant amount of excess heat of scavenging air over the heat required to cool it to 22 °C, which reaches almost half of the available scavenge air heat on the Shanghai-Singapore-Shanghai route. This reveals the possibility of additional cooling the inlet of the turbocharger of the engine with the achieving almost double fuel economy due to the cooling of all cycle air of the low-speed engine, including the air at the inlet.


2020 ◽  
pp. 18-23
Author(s):  
Роман Миколайович Радченко ◽  
Дмитро Вікторович Коновалов ◽  
Максим Андрійович Пирисунько ◽  
Чжан Цян ◽  
Луо Зевей

The efficiency of air cooling at the inlet of the main low speed engine of a transport vessel during operation in tropical climatic conditions on the Shanghai-Karachi-Shanghai route was analyzed. The peculiarity of the tropical climate is the high relative humidity of the air at the same time its high temperatures, and hence the increased thermal load on the cooling system, which requires efficient transformation of the waste heat into the cold in the case of the use of waste heat recovery refrigeration machines. The cooling of the air at the inlet of the low speed engine by absorption lithium bromide chillers, which are characterized by high efficiency of transformation of waste heat into cold – by high coefficients of performance, is investigated. A schematic-construction solution of the air cooling system at the inlet of the ship's main engine using the heat of exhaust gases by an absorption chiller is proposed and analyzed. With this the cooling potential of the inlet air cooling from the current ambient air temperature to 15 ° C and the corresponding heat consumption for the operation of the adsorption chiller, on the one hand, was compared with the available exhaust gas heat potential, on the other hand. The effect of using the exhaust gas heat to cool the air at the inlet of the engine has been analyzed taking into account the changing climatic conditions during the voyage. Enhancement of fuel efficiency of the ship's engine by reducing the inlet air temperature were evaluated by current values of the reduction in specific and total fuel consumption. It is shown that due to the high efficiency of heat conversion in absorption chillers (high coefficients of performance 0.7…0.8), a significant amount of excessive exhaust gas heat over the heat required to cool the ambient air at the inlet of the engine to 15 ° C, which reaches almost half of the available exhaust gas heat during the Shanghai-Karachi-Shanghai route. This reveals the possibility of additional cooling a scavenge air too with almost double fuel economy due to the cooling of all cycle air of the low speed engine, including the air at the inlet.


Sign in / Sign up

Export Citation Format

Share Document