scholarly journals Thermal tension of cylinder covers of transport diesel engines converted to marine diesels

2021 ◽  
Vol 2021 (2) ◽  
pp. 55-64
Author(s):  
Alexander Andreevich Ivnev ◽  
Vladimir Anatoljevich Zhukov ◽  
Yuriy Evgenievich Khryashchyev ◽  
Alexander Ivanovich Yamanin
Keyword(s):  
Cast Iron ◽  
Aluminum Alloys ◽  
Diesel Engines ◽  
Cylinder Head ◽  
Power Plants ◽  
Thermal Loading ◽  
Elevated Temperatures ◽  
Prolonged Exposure ◽  
Physical And Mechanical Properties ◽  
Three Dimensional Model

The article describes the characteristics of thermal loading of the cylinder covers of transport diesel engines during their conversion to marine diesels. The engines of the CHN14/14 type produced by the Yaroslavl Motor Plant are proposed as promising for use in marine power plants. A special feature of the engine design is the individual four-valve cylinder heads, which have a complex geometric shape. The conversion of automobile engines, the cylinder heads of which were made of aluminum alloys, to marine ones is accompanied by an increase in the degree of their acceleration. The cylinder heads in operation experience significant thermal and mechanical loads, which causes the need for increased requirements for the materials of the cylinder heads. The rational choice of the cylinder head material is one of the most important tasks to be solved when upgrading and boosting engines. Experience in the operation of marine diesel engines shows that in order to ensure the required reliability under prolonged exposure to elevated temperatures due to forcing, it is necessary to choose cast iron as a structural material. A three-dimensional model of the cylinder head is developed. When performing the calculations, the boundary conditions are justified, taking into account the local nature of the distribution of thermal and mechanical effects on the diesel cylinder head. As a result of numerical modeling, the stress-strain states of cylinder heads made of high-strength cast iron, ductile iron and cast iron with vermicular graphite are determined and analyzed. There has been proved the preference for using cast irons with vermicular graphite, which have satisfactory casting and physical and mechanical properties. The advantages of using cast iron with vermicular graphite include a decrease in the temperature of the cylinder head in the area of the inter-valve bridge. The possibility of increasing the engine power from 330 to 560 kW when replacing aluminum alloys with cast iron with vermicular graphite for the manufacture of cylinder heads is proved.

Microstructure and Mechanical Properties of a New Ni-Cr-Fe-W-Al Alloy for Advanced Ultra-Supercritical Power Plants

2015 ◽  
Vol 816 ◽  
pp. 586-593 ◽  
Author(s):  
Xian Chao Hao ◽  
Long Zhang ◽  
Xiu Juan Zhao ◽  
Tian Liang ◽  
Ying Che Ma ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Thermodynamic Calculation ◽  
Power Plants ◽  
Elevated Temperatures ◽  
Prolonged Exposure ◽  
Thermal Exposure ◽  
Average Diameter ◽  
Al Alloy ◽  
Microstructural Stability

Optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermodynamic calculation were used to study the phase stability and precipitation in a Ni-Cr-Fe-W-Al alloy. Mechanical properties were also studied. The major precipitates after standard heat treatment or prolonged aging at 725 oC and 800 oC were M23C6 and γ′. M23C6 precipitated intergranularly. P-phase was not detected after thermal exposure, which was different from the results of thermodynamic calculation. The average diameter of γ′ increased with the increasing exposure temperature and time, and could be depicted by the LSW theory. Specimens in solution-annealed condition exhibited excellent ductility. During the prolonged exposure at 725 oC, tensile strength and ductility at room and elevated temperatures kept well, which means this alloy possessed good microstructural stability after a long time exposure.

Some Factors Influencing Cylinder Head Gasket Problems and Design

1973 ◽  
Vol 187 (1) ◽  
pp. 43-49
Author(s):  
M. G. Herrington
Keyword(s):  
Cast Iron ◽  
Diesel Engines ◽  
Cylinder Head ◽  
Cylinder Block ◽  
Temperature Variations ◽  
Factors Influencing ◽  
Test Conditions ◽  
Cylinder Head Gasket ◽  
Block Face

The environment under which a cylinder-head gasket has to function is reviewed and a typical cylinder head to cylinder block assembly is considered, outlining the temperature variations in the inlet and exhaust ports. Curves showing head-face to block-face movement for varying engine speeds and coolant temperatures are reviewed with power units running at accelerated gasket destruction test conditions. Comparisons are made between cast-iron block and aluminium head and cast-iron head and block for both petrol and diesel engines.

Some Factors Influencing Cylinder Head Gasket Problems and Design

1973 ◽  
Vol 187 (1) ◽  
pp. 43-49 ◽  
Author(s):  
M. G. Herrington
Keyword(s):  
Cast Iron ◽  
Diesel Engines ◽  
Cylinder Head ◽  
Cylinder Block ◽  
Temperature Variations ◽  
Factors Influencing ◽  
Test Conditions ◽  
Cylinder Head Gasket ◽  
Block Face

The environment under which a cylinder-head gasket has to function is reviewed and a typical cylinder head to cylinder block assembly is considered, outlining the temperature variations in the inlet and exhaust ports. Curves showing head-face to block-face movement for varying engine speeds and coolant temperatures are reviewed with power units running at accelerated gasket destruction test conditions. Comparisons are made between cast-iron block and aluminium head and cast-iron head and block for both petrol and diesel engines.

BRUSH ALLOY 3

Alloy Digest ◽  
1983 ◽  
Vol 32 (3) ◽  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Copper Alloy ◽  
Elevated Temperatures ◽  
Physical And Mechanical Properties ◽  
Heat Treating ◽  
Good Resistance ◽  
Good Corrosion Resistance

Abstract BRUSH Alloy 3 offers the highest electrical and thermal conductivity of any beryllium-copper alloy. It possesses an excellent combination of moderate strength, good corrosion resistance and good resistance to moderately elevated temperatures. Because of its unique physical and mechanical properties, Brush Alloy 3 finds widespread use in welding applications (RWMA Class 3), current-carrying springs, switch and instrument parts and similar components. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as casting, forming, heat treating, machining, joining, and surface treatment. Filing Code: Cu-454. Producer or source: Brush Wellman Inc..

RED CUT COBALT

Alloy Digest ◽  
1980 ◽  
Vol 29 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Cast Iron ◽  
High Speed ◽  
Elevated Temperatures ◽  
High Speed Steel ◽  
Heat Treating ◽  
High Speeds ◽  
Red Hardness ◽  
Nonferrous Alloys ◽  
Cutting Point

Abstract RED CUT COBALT steel is made by adding 5% cobalt to the conventional 18% tungsten -4% chromium-1% vanadium high-speed steel. Cobalt increases hot or red hardness and thus enables the tool to maintain a higher hardness at elevated temperatures. This steel is best adapted for hogging cuts or where the temperature of the cutting point of the tool in increased greatly. It is well adapted for tools to be used for reaming cast-iron engine cylinders, turning alloy steel or cast iron and cutting nonferrous alloys at high speeds. This datasheet provides information on composition, physical properties, and hardness as well as fracture toughness. It also includes information on forming, heat treating, and machining. Filing Code: TS-367. Producer or source: Teledyne Vasco.

The Role of Free-Living Amoebae Occurring in Heated Effluents as Causative Agents of Human Disease

1983 ◽  
Vol 15 (10) ◽  
pp. 135-147
Author(s):  
Maurice A Shapiro ◽  
Meryl H Karol ◽  
Georg Keleti ◽  
Jan L Sykora ◽  
A J Martinez
Keyword(s):  
Human Disease ◽  
Power Plants ◽  
Elevated Temperatures ◽  
Human Subjects ◽  
Cooling Towers ◽  
Free Living ◽  
Cooling Systems ◽  
Delayed Onset ◽  
Source Of Infection ◽  
Causative Agents

It has been shown that several pathogenic organisms may be frequently found in thermal effluents and cooling systems of coal fired power plants. One of them is pathogenic Naegleria fowleri, the causative agent of an acute fatal human disease - primary amoebic meningoencephalitis (PAM). In our study two out of eight power plants investigated, harbored pathogenic N. fowleri in heated water or cooling towers. The occurrence of this organism was related to elevated temperatures. No significant correlation was found for other biological and chemical parameters. In addition, pathogenic Acanthamoeba which causes granulomatous amoebic encephalitis (GAE) was found in the tested heated effluents from coal fired power plants. Non-pathogenic strains of N. fowleri as well as other free-living and “harmless” amoebae were also very abundant in effluents from all investigated coal fired power plants and cooling towers. It has been reported that several species of nonpathogenic amoebae were isolated from humidifiers and air conditioning systems. Serological testing of symptomatic human subjects has indicated that these organisms may be one of the causative agents of hypersensitivity pneumonitis. An experimental study performed in our laboratory involved testing of guinea pigs sensitized by injection of axenic, non-pathogenic N. gruberi. Delayed onset skin reactivity was apparent in all animals injected with the antigen. Antibodies were detected in all sensitized animals. Bronchial provocation challenge employed to investigate pulmonary hypersensitivity was also used, and yielded positive results. All the sensitized animals displayed delayed onset respiratory responses. The results of this study indicate that not only pathogenic but also non-pathogenic free-living amoebae may be important causative agents of human disease. The occurrence of these organisms in cooling systems from coal fired power plants indicates that these facilities may be an important source of infection.

scholarly journals Three-dimensional CFD modeling of thermal behavior of a disc brake and pad for an automobile

2020 ◽  
Vol 15 (4) ◽  
pp. 543-549
Author(s):  
Haydar Kepekci ◽  
Ergin Kosa ◽  
Cüneyt Ezgi ◽  
Ahmet Cihan
Keyword(s):  
Cast Iron ◽  
Friction Coefficient ◽  
Elevated Temperatures ◽  
Gray Cast Iron ◽  
Three Dimensional ◽  
Brake System ◽  
Gray Cast ◽  
Cfd Modeling ◽  
Disc Brake ◽  
Disc Material

Abstract The brake system of an automobile is composed of disc brake and pad which are co-working components in braking and accelerating. In the braking period, due to friction between the surface of the disc and pad, the thermal heat is generated. It should be avoided to reach elevated temperatures in disc and pad. It is focused on different disc materials that are gray cast iron and carbon ceramics, whereas pad is made up of a composite material. In this study, the CFD model of the brake system is analyzed to get a realistic approach in the amount of transferred heat. The amount of produced heat can be affected by some parameters such as velocity and friction coefficient. The results show that surface temperature for carbon-ceramic disc material can change between 290 and 650 K according to the friction coefficient and velocity in transient mode. Also, if the disc material gray cast iron is selected, it can change between 295 and 500 K. It is claimed that the amount of dissipated heat depends on the different heat transfer coefficient of gray cast iron and carbon ceramics.

INCREASING THE RESOURCE OF DIESEL CYLINDER HEADS BY IMPROVING THE TECHNOLOGY OF THEIR RESTORATION

2020 ◽  
Vol 15 (7) ◽  
pp. 950-957
Author(s):  
G.D. Mezhetskiy ◽  
◽  
V.A. Strelnikov ◽  
Keyword(s):  
Diesel Engines ◽  
Thermal Loading ◽  
Theoretical Calculations ◽  
Operating Conditions ◽  
Advanced Technology ◽  
Temperature Fields ◽  
Cylinder Block ◽  
Diesel Cylinder ◽  
Thermal Intensity

The article presents the results of studies of the thermal fatigue strength of diesel cylinder heads and their resource under operating conditions, by using the most advanced technology for their restoration. Based on the results of theoretical calculations of durability and operational studies, a restoration technology has been proposed, which makes it possible to increase the resource of cylinder heads by 2 ÷ 2.5 times. For this purpose, the non-uniformity of the temperature field on the firing bottom of the cylinder heads of YaMZ-238NB diesel engines was theoretically determined and experimentally confirmed. On the basis of theoretical calculations, the most heatstressed sections of the plane of the cylinder heads of diesel engines bonded to the cylinder block were determined, and the appearance of cracks in them. When developing a method for calculating the temperature fields of the fire bottom, the universal finite element method (FEM) was used. This method makes it possible to take into account the geometry and conditions of thermal loading of the cylinder heads quite accurately. For the determination of temperature fields, a well-founded assignment of the boundary conditions is crucial. With this in mind, a number of surfaces were determined that characterize the durability of the entire part during operation. As a result of calculations carried out on a computer, temperature fields have been obtained that make it possible to analyze the distribution of temperatures and temperature gradients at any point of the fire bottom. The highest temperatures (620...635K) are localized in the central part of the fire bottom, which is two times higher in thermal intensity than the peripheral one and confirms the appearance of cracks in these places during the operation of diesel cylinder heads.

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