Study of Diesel Fuel Heating by Intelligent Materials under Transient High Pressure

2011 ◽  
Vol 480-481 ◽  
pp. 126-131
Author(s):  
Xiao Lu Li ◽  
Le Feng Gu ◽  
Cang Su Xu ◽  
Jun Wang

This paper gives a way which utilizes the intelligent heating materials to preheat diesel fuel in the high-pressure tube in order to improve the cold starting and emissions of engine. A heating model of high-pressure tube was brought forward, and the pressure of tube was measured at a Diesel engine as the computational boundary condition. The unsteady heat transfer was simulated using the computational fluid dynamics by the temperature field and heating effect. Simulation results show that the diesel fuel temperature could improve by the right heating size and temperature in the high-pressure tube.

2011 ◽  
Vol 480-481 ◽  
pp. 120-125 ◽  
Author(s):  
Xiao Lu Li ◽  
Le Feng Gu ◽  
Cang Su Xu ◽  
Ying Li

The PTC materials, as a kind of positive temperature coefficient materials, are used to heat diesel fuel in the high-pressure fuel pipe near the injector in Diesel engine, which have a lot of advantages, such as simple structure, safe and rapid heating, and fixed heating temperature around its Curie point. In order to study its heating effect on diesel fuel of the high pressure fuel pipe, the dynamical models for both the controlled object and PTC heater are presented by the way of lumped parameter, and the heating effects are also simulated and analyzed. The calculation results show that the diesel temperature is heated by the PTC materials effectively. Meanwhile, the heating law by PTC materials heating diesel fuel in the high pressure fuel pipe of engine is also summarized.


Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4419
Author(s):  
Ting Li ◽  
Haiping Shang ◽  
Weibing Wang

A pressure sensor in the range of 0–120 MPa with a square diaphragm was designed and fabricated, which was isolated by the oil-filled package. The nonlinearity of the device without circuit compensation is better than 0.4%, and the accuracy is 0.43%. This sensor model was simulated by ANSYS software. Based on this model, we simulated the output voltage and nonlinearity when piezoresistors locations change. The simulation results showed that as the stress of the longitudinal resistor (RL) was increased compared to the transverse resistor (RT), the nonlinear error of the pressure sensor would first decrease to about 0 and then increase. The theoretical calculation and mathematical fitting were given to this phenomenon. Based on this discovery, a method for optimizing the nonlinearity of high-pressure sensors while ensuring the maximum sensitivity was proposed. In the simulation, the output of the optimized model had a significant improvement over the original model, and the nonlinear error significantly decreased from 0.106% to 0.0000713%.


2014 ◽  
Vol 953-954 ◽  
pp. 66-73
Author(s):  
Yan Ling Liu ◽  
Xue Zeng Shi ◽  
Yuan Yu

This paper presents the design of a solar/gas driving double effect LiBr-H2O absorption system. In order to use solar energy more efficiently, a new kind of solar/gas driving double effect LiBr-H2O absorption system is designed. In this system, the high-pressure generator is driven by conventional energy, natural gas, and solar energy together with water vapor generated in the high-pressure generator, which supplies energy to the low-pressure generator for a double effect absorption system. Simulation results illustrate that this kind of system is feasible and economical. Economic evaluation of several systems is also given in this paper in order to get a clear knowledge of the energy consumption of the system.


Author(s):  
Teguh Taruna Utama

Drinking water sources in Manggarai Regency are mostly supplied from springs. Golo Wua and Golo Watu are two villages in Manggarai Regency that utilize springs. About 12.06 liters/second of drinking water are needed by residants in those villages. This study addresses to forecast the demand of drinking water. This study found that pressure values in manual calculations range from 1.85 meters to 84.22 meters. The minimum pressure requirements from BPP-SPAM is 7 meters (0.7 bar). While the simulation results using the EPANET program, the pressure value is at 1.90 meters up to 84.22 meters. Therefore, the pipe diameter selection is appropriate and the pressure meets the requirements of the BPP-SPAM. Difference between pressure values less than 5% indicates that the selection is the right pipe diameter. Choosing the right pipe diameter will optimize the distribution network in the villages of Golo Wua and Golo Watu. The selected pipe is HDPE type. Selected pipe diameter 1½"; 2"; 2½”; 3"; 4 and 5". The pipe has a pressure resistance of up to 125 meters.


The thickness of the heat-affected zone (HAZ) has a great influence on the strength of the welded joint, so one of the important tasks is to control the HAZ to a small enough level, through using the suitable heat-input (qd). In this study, the authors use SYSWELD software to compute and build a relationship between the heat-input and the thickness of the heat-affected zone in the plate thickness direction to find the right heat-input for researched welding joint. The simulation results show that when welding the root pass with qd > 552 J/mm and the cap pass with 754 J/mm < qd < 1066 J/mm, the thickness of HAZ were increased with a function almost linearly.


2020 ◽  
Vol 198 ◽  
pp. 02006
Author(s):  
Nana Li ◽  
Yongqiang Zhou ◽  
Yanqiang Zhao ◽  
Guiju Li

In order to study the interaction between the left and right tunnels of suspension bridge tunnel-type anchorage, the finite difference numerical software is used to analyze the mechanical properties of the surrounding rock during the construction process. A numerical analysis model based on FLAC3D is established to analyze the stress, displacement and plastic zone changes of the surrounding rock of right tunnel anchor cavern during the construction of left tunnel anchor cavern. The right tunnel anchor cavern is excavated firstly, and then the left tunnel anchor cavern is excavated. The numerical simulation results show that the main displacement of the right tunnel occurs in the construction stage of the anchor plug body and the rear anchor cavern of the left tunnel. During the excavation of the left tunnel, the plastic zones of the left and right tunnel anchor caverns are only connected above the middle of the waist wall. Therefore, it is suggested that during the construction process, especially in the excavation stage of the anchor plug body and the rear anchor cavern, the area above the middle of the tunnel waist wall should be strengthened in time to ensure the construction safety.


Author(s):  
Darlington Njere ◽  
Nwabueze Emekwuru

The evolution of diesel fuel injection technology, to facilitate strong correlations of in-cylinder spray propagation with injection conditions and injector geometry, is crucial in facing emission challenges. More observations of spray propagation are, therefore, required to provide valuable information on how to ensure that all the injected fuel has maximum contact with the available air, to promote complete combustion and reduce emissions. In this study, high pressure diesel fuel sprays are injected into a constant-volume chamber at injection and ambient pressure values typical of current diesel engines. For these types of sprays the maximum fuel liquid phase penetration is different and reached sooner than the maximum fuel vapour phase penetration. Thus, the vapour fuel could reach the combustion chamber wall and could be convected and deflected by swirling air. In hot combustion chambers this impingement can be acceptable but this might be less so in larger combustion chambers with cold walls. The fuel-ambient mixture in vapourized fuel spray jets is essential to the efficient performance of these engines. For this work, the fuel vapour penetration values are presented for fuel injectors of different k-factors. The results indicate that the geometry of fuel injectors based on the k-factors appear to affect the vapour phase penetration more than the liquid phase penetration. This is a consequence of the effects of the injector types on the exit velocity of the fuel droplets.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4951


Author(s):  
Юрий Николаевич Рыбаков ◽  
Александр Васильевич Дедов ◽  
Роман Игоревич Кюннап ◽  
Сергей Владимирович Ларионов

Исследована проницаемость фторированного полиэтилена высокого давления (ПВД), предназначенного для изготовления ремонтных и технологических вкладышей резервуаров складов временного хранения топлива. Использование таких вкладышей позволяет снизить технологические потери углеводородов и увеличить надежность хранилищ из полимерных материалов. В качестве объекта исследования использовали пленки ПВД 10204-003 толщиной 100 мкм. Проницаемость пленок определяли при контакте с бензином марок Нормаль-80, Премиум-95, авиационным керосином ТС-1 и дизельным топливом. Рассмотрен механизм формирования структуры поверхностного фторированного слоя. Исследована кинетика изменения коэффициента проницаемости исходного и модифицированного полиэтилена в течение возможного срока хранения топлив. По результатам исследования установлено: 1) в полиэтилене перенос топлива протекает в две стадии, что определяется раздельной диффузией низкомолекулярных и высокомолекулярных фракций углеводородов; 2) фторирование полиэтилена приводит к уменьшению коэффициента проницаемости (что имеет практическое значение для сохранения качества топлива), но не влияет на перенос фракции углеводородов минимальной молекулярной массы. The permeability of fluorinated high-pressure polyethylene (HDPE), intended for the manufacture of repair and technological liners of tanks for temporary fuel storage has been investigated. As the object of research, 10204-003 HDPE films with 100 μm thickness were used. The permeability of the films was determined by contact with gasoline of the Normal-80 and Premium-95 brands, aviation kerosene TS-1, and diesel fuel. The formation mechanism of the surface fluorinated layer structure was considered. The kinetics of changes in the permeability coefficient of the original and modified polyethylene during the possible fuel storage period has been studied. It has been established that the transfer of fuel in polyethylene proceeds in two stages, which is determined by the separate diffusion of low-molecular and high-molecular hydrocarbon fractions. Fluoridation of polyethylene decreases the permeability coefficient, but does not affect the transfer of hydrocarbon fraction with the minimum molecular weight.


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