Aim To study fuel dispersion in fuel air explosive(FAE) and computational ways of fuel dispersion velocity in the near area. Methods\ The dispersion process of fuel in FAE was analyzed by the use of results measured ...Aim To study fuel dispersion in fuel air explosive(FAE) and computational ways of fuel dispersion velocity in the near area. Methods\ The dispersion process of fuel in FAE was analyzed by the use of results measured with KODAK EKTAPRO EM Motion Analyzer and setting up mechanical models. Results\ Computational methods for fuel dispersion velocity in the acceleration stage is given and taken as a base for the study of fuel dispersion in the intermediate and the far area. Conclusion\ When the fuel flow velocity is higher than that of the explosion gas in the center cavity, the fuel divides with the explosion gas and its velocity of flow reaches a maximum. The acceleration stage ends at that time. The fuel dispersion velocity at this time is the initial conditions for numeral analyses of dispersion process in the intermediate and far areas.展开更多
Fuel Coolant Interactions (FCIs) are important issues in nuclear reactor severe accident analysis. In FCIs, fragmentation model of molten droplets is a key factor to estimate degree of possible damage. In this paper, ...Fuel Coolant Interactions (FCIs) are important issues in nuclear reactor severe accident analysis. In FCIs, fragmentation model of molten droplets is a key factor to estimate degree of possible damage. In this paper, the mixing process in FCIs is studied by the simulation of MIXA experiment with hydrodynamic fragmentation model. The result shows that hydrodynamic fragmentation model underestimates the fragmentation rate of high temperature molten droplets under the condition of low Weber numbers. It is concluded that models based on thermal fragmentation mechanism should be adopted to analyze the FCI process and its consequence.展开更多
A series of experiments of the premixing stage of fuel-coolant interactions (FCI), namely the particles falling into water, were carried out. The force on the particles during the course of falling has been studied. T...A series of experiments of the premixing stage of fuel-coolant interactions (FCI), namely the particles falling into water, were carried out. The force on the particles during the course of falling has been studied. The dropping character of hot particle was influenced by three main parameters, i.e., particle temperature, particle diameter and coolant subcooling that varied over a wide range. A high-speed camera recorded the falling speed of the particle and the moving curves were obtained. The experimental results showed that for the film boiling on the surface of particle and water, the temperature increase of either particle or coolant would slow down the particle falling velocity. The falling velocity of particle in small diameter is lower than that of the bigger particle. The present work can provide an experimental foundation for further investigation of high-speed transient evaporation heat transfer.展开更多
This paper presents the experimental results of composition changes of heavy fuel oil by stmulating weathering in static seawater under natural environmental conditions. The results indicate： n-C10 to n-C15 were lost...This paper presents the experimental results of composition changes of heavy fuel oil by stmulating weathering in static seawater under natural environmental conditions. The results indicate： n-C10 to n-C15 were lost gradually in 24 weeks and the relative abundance of alkanes with long chains （〉n-C19） increased markedly. The aromatic compounds with less than two tings （except C4N） were completely lost in 24 weeks and CnP and CnD became the main aromatics in the heavy fuel oil after 24 weeks. The ratios of n- C1/Pristane （Pr） and n-C18 Phytane （Ph） were suitable for identifying lightly weathered （3 weeks） heavy fuel oil. The ratios of n-ClT/n-C18 and Pr/Ph were suitable for identifying moderately weathered heavy fuel oil （12 weeks）; the ratios of C2D/C2P and C3D/C3P did not change significantly in 24 weeks and were more suitable for identifying moderately weathered heavy fuel oil （24 weeks）.展开更多
The amount of ethylene in refinery off-gas is high with a mass fraction of 20%,but the refinery off-gas is usually used as fuel gas in most refineries.The separation and recovery of ethylene is of remarkable significa...The amount of ethylene in refinery off-gas is high with a mass fraction of 20%,but the refinery off-gas is usually used as fuel gas in most refineries.The separation and recovery of ethylene is of remarkable significance for saving energy and reducing carbon dioxide emission.The aim of this paper is to use a novel absorbent mesitylene for the ethylene absorption process and assess its application feasibility through the ethylene + mesitylene vapor-liquid equilibrium data measurement and its binary interaction parameter correlation,as well as the simulation for ethylene separation process.展开更多
To promote the fuel utilization efficiency of IC engine, an approach was proposed for IC engine coolant energy recovery based on low-temperature organic Rankine cycle(ORC). The ORC system uses IC engine coolant as hea...To promote the fuel utilization efficiency of IC engine, an approach was proposed for IC engine coolant energy recovery based on low-temperature organic Rankine cycle(ORC). The ORC system uses IC engine coolant as heat source, and it is coupled to the IC engine cooling system. After various kinds of organic working media were compared, R124 was selected as the ORC working medium. According to IC engine operating conditions and coolant energy characteristics, the major parameters of ORC system were preliminary designed. Then, the effects of various parameters on cycle performance and recovery potential of coolant energy were analyzed via cycle process calculation. The results indicate that cycle efficiency is mainly influenced by the working pressure of ORC, while the maximum working pressure is limited by IC engine coolant temperature. At the same working pressure, cycle efficiency is hardly affected by both the mass flow rate and temperature of working medium. When the bottom cycle working pressure arrives at the maximum allowable value of 1.6 MPa, the fuel utilization efficiency of IC engine could be improved by 12.1%.All these demonstrate that this low-temperature ORC is a useful energy-saving technology for IC engine.展开更多
Fossil fuels are non-renewable, and their quantities have been reducing because of pumping. On the other hand, the traffic is still developing and needs for fuels are growing. As a consequence people are forced to loo...Fossil fuels are non-renewable, and their quantities have been reducing because of pumping. On the other hand, the traffic is still developing and needs for fuels are growing. As a consequence people are forced to look for other sources of getting fuel. Additional reason for this has been steadily boosting the prices of crude oil and gas. Diesel, as fuel that is often used, is possible to produce from different feedstock （oil rape, soybean, sunflower, palm, waste animal fats, algae, etc）. In this paper, the author analyzes the possibility of obtaining biodiesel from algae and the feasibility of such a method of producing biodiesel. Algae for biodiesel production are analyzed and the systems in which they are growing are described. Experience in this area is described as well as opportunities for further development of technology for getting biodiesel from algae. Algae are very resistant and can grow virtually anywhere in the desert, in salt and fresh water and even in the waste water. Algae can reproduce quickly; they use C02 for photosynthesis and less water than other crops. Bio fuel from algae is biodegradable and contains no sulphur and it is not toxic.展开更多
A special visible experiment facility has been designed and built, and an observable experiment is per- formed by pouring one or several high-temperature particles into a water pool in the facility. The experiment res...A special visible experiment facility has been designed and built, and an observable experiment is per- formed by pouring one or several high-temperature particles into a water pool in the facility. The experiment result has verified Yang’s evaporation drag model, which holds that the non-symmetric profile of the local evaporation rate and the local density of vapor would bring about a resultant force on the hot particle so as to resist its motion. How- ever, in Yang’s evaporation drag model, radiation heat transfer is taken as the only way to transfer heat from hot par- ticle to the vapor-liquid interface, and all of the radiation energy is deposited on the vapor-liquid interface and con- tributed to the vaporization rate and mass balance of the vapor film. In improved model heat conduction and heat convection are taken into account. This paper presents calculations of the improved model, putting emphasis on the effect of hot particle’s temperature on the radiation absorption behavior of water.展开更多
Recently ammonia has been investigated as a fuel for SOFCs （solid oxide fuel cells）. Ammonia is widely produced and transported globally, and stores hydrogen in its bonds making it an excellent fuel for fuel cells. ...Recently ammonia has been investigated as a fuel for SOFCs （solid oxide fuel cells）. Ammonia is widely produced and transported globally, and stores hydrogen in its bonds making it an excellent fuel for fuel cells. The high temperature of SOFCs allows for internal decomposition of ammonia. Previous models of ammonia-fed SOFCs treat ammonia decomposition as having first order dependence on ammonia partial pressure, and ignore the effect of hydrogen inhibition. However, research has shown that at low temperatures （≤ 600 ℃） and low ammonia partial pressures, the rate of ammonia decomposition is inhibited by the presence of hydrogen. This hydrogen inhibition effect was studied and implemented in a model of an ammonia decomposition reactor. Results showed that it may significantly decrease the rate of hydrogen generation. This work sets the foundation for more accurate modelling of intermediate temperature ammonia-fed SOFCs.展开更多
Coacervation of oxidized glutathione(GSSG)and a cationic surfactant,didodecyldimethylammonium bromide(DDAB),was constructed mainly driven by the electrostatic and hydrophobic interactions.The pH-dependent coacervate o...Coacervation of oxidized glutathione(GSSG)and a cationic surfactant,didodecyldimethylammonium bromide(DDAB),was constructed mainly driven by the electrostatic and hydrophobic interactions.The pH-dependent coacervate of GSSG-DDAB(1∶4,mol/mol)was analyzed.Under acidic and neutral conditions,a turbid suspension of droplets is observed,and alkaline pH results in the phase separation of coacervates as the top phase.The coacervate phase exhibits good performance(extraction efficiency>85%)in extracting several dyes from water,including brilliant yellow,acid red 13,cresyl violet acetate,eriochrom blue SE,and 4-hydroxyazobenzene.The dyes are added into the suspension in acidic conditions.Then,the dyes are enriched and extracted along with the coacervates as the top phase when pH is adjusted to~10.Coacervation of GSSG with DDAB provides a simple approach to extract organic pollutants in wastewater treatment.展开更多
文摘Aim To study fuel dispersion in fuel air explosive(FAE) and computational ways of fuel dispersion velocity in the near area. Methods\ The dispersion process of fuel in FAE was analyzed by the use of results measured with KODAK EKTAPRO EM Motion Analyzer and setting up mechanical models. Results\ Computational methods for fuel dispersion velocity in the acceleration stage is given and taken as a base for the study of fuel dispersion in the intermediate and the far area. Conclusion\ When the fuel flow velocity is higher than that of the explosion gas in the center cavity, the fuel divides with the explosion gas and its velocity of flow reaches a maximum. The acceleration stage ends at that time. The fuel dispersion velocity at this time is the initial conditions for numeral analyses of dispersion process in the intermediate and far areas.
基金National Natural Science Foundation of China (No.50576050)
文摘Fuel Coolant Interactions (FCIs) are important issues in nuclear reactor severe accident analysis. In FCIs, fragmentation model of molten droplets is a key factor to estimate degree of possible damage. In this paper, the mixing process in FCIs is studied by the simulation of MIXA experiment with hydrodynamic fragmentation model. The result shows that hydrodynamic fragmentation model underestimates the fragmentation rate of high temperature molten droplets under the condition of low Weber numbers. It is concluded that models based on thermal fragmentation mechanism should be adopted to analyze the FCI process and its consequence.
基金the National Natural Science Foundation of China (No. 50376036)
文摘A series of experiments of the premixing stage of fuel-coolant interactions (FCI), namely the particles falling into water, were carried out. The force on the particles during the course of falling has been studied. The dropping character of hot particle was influenced by three main parameters, i.e., particle temperature, particle diameter and coolant subcooling that varied over a wide range. A high-speed camera recorded the falling speed of the particle and the moving curves were obtained. The experimental results showed that for the film boiling on the surface of particle and water, the temperature increase of either particle or coolant would slow down the particle falling velocity. The falling velocity of particle in small diameter is lower than that of the bigger particle. The present work can provide an experimental foundation for further investigation of high-speed transient evaporation heat transfer.
文摘This paper presents the experimental results of composition changes of heavy fuel oil by stmulating weathering in static seawater under natural environmental conditions. The results indicate： n-C10 to n-C15 were lost gradually in 24 weeks and the relative abundance of alkanes with long chains （〉n-C19） increased markedly. The aromatic compounds with less than two tings （except C4N） were completely lost in 24 weeks and CnP and CnD became the main aromatics in the heavy fuel oil after 24 weeks. The ratios of n- C1/Pristane （Pr） and n-C18 Phytane （Ph） were suitable for identifying lightly weathered （3 weeks） heavy fuel oil. The ratios of n-ClT/n-C18 and Pr/Ph were suitable for identifying moderately weathered heavy fuel oil （12 weeks）; the ratios of C2D/C2P and C3D/C3P did not change significantly in 24 weeks and were more suitable for identifying moderately weathered heavy fuel oil （24 weeks）.
基金Supported by the National Natural Science Foundation of China （50890184） the National Basic Research Program of China （2011CB201306）
文摘The amount of ethylene in refinery off-gas is high with a mass fraction of 20%,but the refinery off-gas is usually used as fuel gas in most refineries.The separation and recovery of ethylene is of remarkable significance for saving energy and reducing carbon dioxide emission.The aim of this paper is to use a novel absorbent mesitylene for the ethylene absorption process and assess its application feasibility through the ethylene + mesitylene vapor-liquid equilibrium data measurement and its binary interaction parameter correlation,as well as the simulation for ethylene separation process.
基金Project(2011CB707201)supported by the National Basic Research Program of ChinaProject(51376057)supported by the National Natural Science Foundation of China
文摘To promote the fuel utilization efficiency of IC engine, an approach was proposed for IC engine coolant energy recovery based on low-temperature organic Rankine cycle(ORC). The ORC system uses IC engine coolant as heat source, and it is coupled to the IC engine cooling system. After various kinds of organic working media were compared, R124 was selected as the ORC working medium. According to IC engine operating conditions and coolant energy characteristics, the major parameters of ORC system were preliminary designed. Then, the effects of various parameters on cycle performance and recovery potential of coolant energy were analyzed via cycle process calculation. The results indicate that cycle efficiency is mainly influenced by the working pressure of ORC, while the maximum working pressure is limited by IC engine coolant temperature. At the same working pressure, cycle efficiency is hardly affected by both the mass flow rate and temperature of working medium. When the bottom cycle working pressure arrives at the maximum allowable value of 1.6 MPa, the fuel utilization efficiency of IC engine could be improved by 12.1%.All these demonstrate that this low-temperature ORC is a useful energy-saving technology for IC engine.
文摘Fossil fuels are non-renewable, and their quantities have been reducing because of pumping. On the other hand, the traffic is still developing and needs for fuels are growing. As a consequence people are forced to look for other sources of getting fuel. Additional reason for this has been steadily boosting the prices of crude oil and gas. Diesel, as fuel that is often used, is possible to produce from different feedstock （oil rape, soybean, sunflower, palm, waste animal fats, algae, etc）. In this paper, the author analyzes the possibility of obtaining biodiesel from algae and the feasibility of such a method of producing biodiesel. Algae for biodiesel production are analyzed and the systems in which they are growing are described. Experience in this area is described as well as opportunities for further development of technology for getting biodiesel from algae. Algae are very resistant and can grow virtually anywhere in the desert, in salt and fresh water and even in the waste water. Algae can reproduce quickly; they use C02 for photosynthesis and less water than other crops. Bio fuel from algae is biodegradable and contains no sulphur and it is not toxic.
基金Partially financed by National Natural Science Fund of China (No. 50046026 & No. 50376036) and 985 Engineering Fund of Shanghai Jiaotong University.
文摘A special visible experiment facility has been designed and built, and an observable experiment is per- formed by pouring one or several high-temperature particles into a water pool in the facility. The experiment result has verified Yang’s evaporation drag model, which holds that the non-symmetric profile of the local evaporation rate and the local density of vapor would bring about a resultant force on the hot particle so as to resist its motion. How- ever, in Yang’s evaporation drag model, radiation heat transfer is taken as the only way to transfer heat from hot par- ticle to the vapor-liquid interface, and all of the radiation energy is deposited on the vapor-liquid interface and con- tributed to the vaporization rate and mass balance of the vapor film. In improved model heat conduction and heat convection are taken into account. This paper presents calculations of the improved model, putting emphasis on the effect of hot particle’s temperature on the radiation absorption behavior of water.
文摘Recently ammonia has been investigated as a fuel for SOFCs （solid oxide fuel cells）. Ammonia is widely produced and transported globally, and stores hydrogen in its bonds making it an excellent fuel for fuel cells. The high temperature of SOFCs allows for internal decomposition of ammonia. Previous models of ammonia-fed SOFCs treat ammonia decomposition as having first order dependence on ammonia partial pressure, and ignore the effect of hydrogen inhibition. However, research has shown that at low temperatures （≤ 600 ℃） and low ammonia partial pressures, the rate of ammonia decomposition is inhibited by the presence of hydrogen. This hydrogen inhibition effect was studied and implemented in a model of an ammonia decomposition reactor. Results showed that it may significantly decrease the rate of hydrogen generation. This work sets the foundation for more accurate modelling of intermediate temperature ammonia-fed SOFCs.
文摘Coacervation of oxidized glutathione(GSSG)and a cationic surfactant,didodecyldimethylammonium bromide(DDAB),was constructed mainly driven by the electrostatic and hydrophobic interactions.The pH-dependent coacervate of GSSG-DDAB(1∶4,mol/mol)was analyzed.Under acidic and neutral conditions,a turbid suspension of droplets is observed,and alkaline pH results in the phase separation of coacervates as the top phase.The coacervate phase exhibits good performance(extraction efficiency>85%)in extracting several dyes from water,including brilliant yellow,acid red 13,cresyl violet acetate,eriochrom blue SE,and 4-hydroxyazobenzene.The dyes are added into the suspension in acidic conditions.Then,the dyes are enriched and extracted along with the coacervates as the top phase when pH is adjusted to~10.Coacervation of GSSG with DDAB provides a simple approach to extract organic pollutants in wastewater treatment.
