A two-component heavy fuel oil evaporation model for CFD studies in marine Diesel engines

Fuel ◽  
2014 ◽  
Vol 115 ◽  
pp. 145-153 ◽  
Author(s):  
Nikolaos Stamoudis ◽  
Christos Chryssakis ◽  
Lambros Kaiktsis
2019 ◽  
Vol 20 (8-9) ◽  
pp. 967-985 ◽  
Author(s):  
Yuhai He ◽  
Peilin Zhou ◽  
Liangtao Xie ◽  
Jiyun Zhang

Lubrication of cylinders between liners and rings is one of the crucial factors that affects the efficient operation of diesel engines. Marine diesel engines usually use inferior heavy fuel oil with high sulphur content, and the acidic substances formed by fuel combustion need alkaline cylinder oil to neutralize. For the operational cost to a marine engine, besides fuel oil, cylinder oil also takes a big share. This article first analyses the advantages and disadvantages of existing cylinder lubrication systems with regard to oil injection control. Second, the control parameters and variables such as the oil injection pressure, timing, oil feed rate and reliability are analysed, and the corresponding control schemes formulated. Third, the control strategies are developed in detail. Finally, verification tests are carried out on an actual engine, with the results showing that the control strategies developed in this article provide a stable, cost-effective, creative and excellent solution for cylinder lubrication with reduced cylinder wear. A thin and uniform oil film distribution is retained on the liner surface, with savings in cylinder oil consumption, lower particulate matter emission levels and improved cylinder liner and piston rings running conditions. The experimental results show that the oil consumption could be reduced by up to 50%.


2006 ◽  
Vol 7 (2) ◽  
pp. 181-199 ◽  
Author(s):  
L Goldsworthy

A simplified model is presented for vaporization and combustion of heavy residual based fuel oil in high-pressure sprays, in the context of marine diesel engines. The fuel is considered as a mix of residual base and cutter stock. The model accounts for multiple fuel components as well as limited diffusion rates and thermal decomposition rates within droplets by the use of straight-line relationships for the saturation pressure of combustible fuel vapour at the droplet surface as functions of droplet temperature. The energy required for decomposition of heavy molecules is accounted for. Combustion is modelled using a timescale that is the sum of a kinetic timescale based on a single-step reaction and a turbulent timescale based on turbulent mixing rates. The ignition timescale is based on a simple three-equation model. Cellwise ignition is employed. The heavy fuel oil model is applied to two different constant volume chambers that are used to test ignition and combustion quality of marine heavy fuel oil, using the computational fluid dynamics code StarCD version 3.2. Good agreement is shown between trends in measured and computed data including ignition delay, burn rate and spatial distribution of spray and flame parameters. The model is tested for two representative fuels, one with good ignition and combustion properties and one poor. Essentially only two parameters need to be changed to set the fuel quality. These are the ignition delay factor and the activation energy for the high-temperature kinetics. Further tuning of the model to specific fuels is possible by modifying the saturation temperature relationships.


2010 ◽  
Author(s):  
Herbert Roeser ◽  
Dilip Kalyankar

Ships are an integral part of modern commercial transport, leisure travel, and military system. A diesel engine was used for the first time for the propulsion of a ship sometime in the 1910s and has been the choice for propulsion and power generation, ever since. Since the first model used in ship propulsion, the diesel engine has come a long way with several technological advances. A diesel engine has a particularly high thermal efficiency. Added to it, the higher energy density of the diesel fuel compared to gasoline fuel makes it inherently, the most efficient internal combustion engine. The modern diesel engine also has a very unique ability to work with a variety of fuels like diesel, heavy fuel oil, biodiesel, vegetable oils, and several other crude oil distillates which is very important considering the shortage of petroleum fuels that we face today. In spite of being highly efficient and popular and in spite of all the technological advances, the issue of exhaust gas emissions has plagued a diesel engine. This issue has gained a lot of importance since 1990s when IMO, EU, and the EPA came up with the Tier I exhaust gas emission norms for the existing engine in order to reduce the NOx and SOx. Harsher Tier II and Tier III norms were later announced for newer engines. Diesel fuels commonly used in marine engines are a form of residual fuel, also know as Dregs or Heavy Fuel Oil and are essentially the by products of crude oil distillation process used to produce lighter petroleum fuels like marine distillate fuel and gasoline. They are cheaper than marine distillate fuels but are also high in nitrogen, sulfur and ash content. This greatly increases the NOx and SOx in the exhaust gas emission. Ship owners are trapped between the need to use residual fuels, due to cost of the large volume of fuel consumed, in order to keep the operation of their ships to a competitive level on one hand and on the other hand the need to satisfy the stringent pollution norms as established by the pollution control agencies worldwide. Newer marine diesel engines are being designed to meet the Tier II and Tier III norms wherever applicable but the existing diesel engine owners are still operating their engines with the danger of not meeting the applicable pollution norms worldwide. Here we make an effort to look at some of the measure that the existing marine diesel engine owners can take to reduce emissions and achieve at least levels prescribed in Tier I. Proper maintenance and upkeep of the engine components can be effectively used to reduce the exhaust gas emission. We introduced a pilot program on diesel engine performance monitoring in North America about two years ago and it has yielded quite satisfying results for several shipping companies and more and more ship owners are looking at the option of implementing this program on their ships.


2008 ◽  
Vol 45 (04) ◽  
pp. 191-193
Author(s):  
Wei Hai-jun ◽  
Wang Guo-you ◽  
Wang Xiao-rui

The purpose of this paper is to study the applicability of thermal processed fuel oil (hereafter called waste plastic disposal, or WPD) of diesel engines using low-quality fuel oil. In the experiment, stability of engine operation and components of exhaust gas, such as NOx and COx, were inspected from basic and applicable points of view. This paper illustrates a new test and result of WPD oil applied to marine diesel engines. In recent years, efforts have to be made to develop an advanced technique for recycling waste plastics in order to use scrapped plastics as fuel for diesel engines. It is very important and necessary for us to cope with the increasing calorific value and to satisfy the growing need of environment protection. The experimental fuel oil is obtained by a mixing of diesel oil, WPD, and water.


2020 ◽  
Vol 20 (3) ◽  
pp. 1549-1564 ◽  
Author(s):  
Fan Zhang ◽  
Hai Guo ◽  
Yingjun Chen ◽  
Volker Matthias ◽  
Yan Zhang ◽  
...  

Abstract. Studies of detailed chemical compositions in particles with different size ranges emitted from ships are in serious shortage. In this study, size-segregated distributions and characteristics of particle mass, organic carbon (OC), elemental carbon (EC), 16 EPA polycyclic aromatic hydrocarbons (PAHs) and 25 n-alkanes measured aboard 12 different vessels in China are presented. The results showed the following. (1) More than half of the total particle mass, OC, EC, PAHs and n-alkanes were concentrated in fine particles with aerodynamic diameter (Dp) < 1.1 µm for most of the tested ships. The relative contributions of OC, EC, PAH and alkanes to the size-segregated particle mass are decreasing with the increase in particle size. However, different types of ships showed quite different particle-size-dependent chemical compositions. (2) In fine particles, the OC and EC were the dominant components, while in coarse particles, OC and EC only accounted for very small proportions. With the increase in particle size, the OC / EC ratios first decreased and then increased, having the lowest values for particle sizes between 0.43 and 1.1 µm. (3) Out of the four OC fragments and three EC fragments obtained in thermal–optical analysis, OC1, OC2 and OC3 were the dominant OC fragments for all the tested ships, while EC1 and EC2 were the main EC fragments for ships running on heavy fuel oil (HFO) and marine-diesel fuel, respectively; different OC and EC fragments presented different distributions in different particle sizes. (4) The four-stroke low-power diesel fishing boat (4-LDF) had much higher PAH emission ratios than the four-stroke high-power marine-diesel vessel (4-HMV) and two-stroke high-power heavy-fuel-oil vessel (2-HHV) in fine particles, and 2-HHV had the lowest values. (5) PAHs and n-alkanes showed different profile patterns for different types of ships and also between different particle-size bins, which meant that the particle size should be considered when source apportionment is conducted. It is also noteworthy from the results in this study that the smaller the particle size, the more toxic the particle was, especially for the fishing boats in China.


Author(s):  
Tatsuro Tsukamoto ◽  
Kenji Ohe ◽  
Hiroshi Okada

In these years, a problem of air pollution in a global scale becomes a matter of great concern. In such social situation, diesel engines are strongly required to reduce the NOx and particulate emission in the exhaust gas. In this paper, measurements of particulate emissions from a low speed two-stroke marine diesel engine were conducted with several kinds of diesel oil and a heavy fuel oil, to know the characteristics of particulate emissions at the present situation. The effects of engine load and sulfur content of the fuel on the particulate emission have been examined. The particulate emission from the test engine was measured by partial-flow dilution tunnel system, and particulate matter collected on the filter was divided into four components, SOF (soluble organic fraction), sulfate, bound water and dry soot, by Soxlet extraction and ion chromatograph. Results show that the particulate emission from the test engine operated with heavy fuel oil is three times as much as the value with diesel oil and that not only sulfate but SOF and dry soot concentration increase with the increase in fuel sulfur content. It is also found that the conversion rate from sulfur in fuel into sulfate in particulate matter is nearly independent of the sulfur content in the fuel and increases with the increase in the engine load.


2010 ◽  
Vol 41 (12) ◽  
pp. 1143-1151 ◽  
Author(s):  
Zhongqing Zheng ◽  
Xiaochen Tang ◽  
Akua Asa-Awuku ◽  
Heejung S. Jung

Author(s):  
Hyoung-Keun Park ◽  
Sang-Hak Ghal ◽  
Tae-Hyung Park ◽  
Yong-Hee Ahn ◽  
Sung-Hyeok Kim

Straight vegetable oil (SVO) fuels such as palm oil, animal fat oil and waste vegetable oil were tested as fuels in a single-cylinder diesel engine to evaluate applicability to medium-speed diesel engines. Fuel-related properties of the SVO were assessed and compared with conventional marine diesel fuel oil (MDO). The total acid number (TAN) of the SVO fuels changed during a short interval in a drying oven which heated the SVO fuels to 170 degrees Celsius for several weeks. The SVO have not gone rancid any further after reaching limit. And the TAN of the SVO fuels was not related to corrosion of the parts. The SVO fuels needed to be heated to an appropriate temperature to use as fuel of the engine since the SVO fuels are more viscous than conventional diesel fuels. Both the injection period and the injection pressure increased due to low heating values of the SVO fuels. By the same token, fuel oil consumption increased over 10%. The overall exhaust emissions were lower with the SVO fuels, but NOx emission was as much as MDO at the higher loads.


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