In order to improve the efficiency of heating and the uniformity of temperature distribution in recycling asphalt mixtures, a pyramidal radiation heater is designed. The principles of designing horn surface size and a...In order to improve the efficiency of heating and the uniformity of temperature distribution in recycling asphalt mixtures, a pyramidal radiation heater is designed. The principles of designing horn surface size and antenna length are established according to the law of energy conservation and microwave antenna radiation theory. Modeling and simulation are carried out using IE3D software. The simulation results demonstrate that, with a fixed horn surface size, the shortened electric antenna length is the main factor leading to the improved heating uniformity. On the other hand, with a fixed antenna length and diminished surface size, the standing wave ratio decreases with the improved radiation efficiency. Furthermore, the efficiency of radiation drops with increased distance between the horn surface and the asphalt pavement. Microwave heating experiments are carried out using this type of heater. The temperature distribution of asphalt samples is obtained by the grid temperature measurement method, and Matlab simulation is performed. The experimental results are in good agreement with the simulation.展开更多
In order to study the thermoelectric efficiency of microwave heating and reproduction of asphalt pavements and the uniformity of reproduction temperature distribution, a waveguide excitation cavity is designed and app...In order to study the thermoelectric efficiency of microwave heating and reproduction of asphalt pavements and the uniformity of reproduction temperature distribution, a waveguide excitation cavity is designed and applied to the structural design of a microwave heater. The structural sizes of the incentive cavities are determined based on the waveguide transmission line theory. Using IE3D software, electromagnetic simulations are respectively carried out in four different situations, including the distances between the magnetron probes （antennas） and a short-circuit board, different horn electric lengths and aperture sizes, different dielectric properties of the asphalt mixture, and the distances between the asphalt surface and the mouth cavity. The results show that, when the distance between the magnetron probe and the short-circuit board is 32.5 ram, it is the best installation site; reduction of aerial length is the main factor in improving the heating uniformity. When the aggregate is limestone, the best heating effect can be produced. Maximum radiation efficiency can be realized by adjusting the space between the heater radiation port and the asphalt pavement. The experimental results of asphalt mixture heating in four different situations have a substantial agreement with the simulation results, which confirms that the developed microwave heater can achieve better impedance matching, thus improving the quality and efficiency of heating regeneration.展开更多
Metal organic chemical vapor deposition(MOCVD) is a key equipment in the manufacturing of semiconductor optoelectronic devices and microwave devices in industry. Heating system is a vital part of MOCVD. Specific heati...Metal organic chemical vapor deposition(MOCVD) is a key equipment in the manufacturing of semiconductor optoelectronic devices and microwave devices in industry. Heating system is a vital part of MOCVD. Specific heating device and thermal control technology are needed for each new reactor design. By using resistance-wire heating MOCVD reaction chamber model, thermal analysis and structure optimization of the reactor were developed from the vertical position and the distance between coils of the resistance-wire heater. It is indicated that, within a certain range, the average temperature of the graphite susceptor varies linearly with the vertical distance of heater to susceptor, and with the changed distances between the coils; furthermore, single resistance-wire heater should be placed loosely in the internal and tightly in the external. The modulate accuracy of the temperature field approximately equals the change of the average temperature corresponding to the change of the coil position.展开更多
The numerous environmental protection equipments for desulfuration,denitration,and precipitation have been installed in the domestic coal-fired power plants,while the investment and energy consumption of the units inc...The numerous environmental protection equipments for desulfuration,denitration,and precipitation have been installed in the domestic coal-fired power plants,while the investment and energy consumption of the units increase correspondingly.To reduce the operational cost and initial investment as much as possible,the working processes of the environmental protection equipments are optimized in the design and some new technologies are adopted for energy saving.These technologies include the SCR,SNCR,combined SCR and SNCR for denitration device,system without gas-gas heater design for desulfuration,desulfuration system without bypass,booster fan and induced draft fan integrated,stack and cooling tower integrated and so on.However,such measures may cause some new problems during the operation of the equipment.The problems are summarized and analyzed thoroughly and the feasible methods are provided to solve them,which could decrease the operational risk of units.The present discussion can also improve the further design of environmental protection equipments to ensure the long-term steady operation of the units.展开更多
The project has as its aim the design and implementation of the control of temperature in the cockpit of the prototype of neonatal life support equipment ESVIN based on the international standard IEC 60601-2-19 concer...The project has as its aim the design and implementation of the control of temperature in the cockpit of the prototype of neonatal life support equipment ESVIN based on the international standard IEC 60601-2-19 concerning the basic security and operation of the neonatal incubators. The prototype has been developed and is important because the cockpit is a new concept of medical equipment of neonatal life support. There was a modeling of the system of heating of the incubator using the concepts of system identification with the purpose of finding a mathematical model that describes the dynamic behavior of the system. Then, design and implement the strategy of feedback control with digital PID （proportional-integral-derivative） algorithm. The model allowed the design and implementation of a digital PID controller that meets in a satisfactory manner with the requirements, in accordance with the international standard. The control system implemented in the neonatal incubator ESVIN improved the effectiveness of the neonatal life support equipment in regard to temperature controller of the cockpit.展开更多
基金The Key Project of Science and Technology of Ministry of Education(No.03081,105085)the SciTech Achievements Transformation Program of Jiangsu Province(No.BA2006068)
文摘In order to improve the efficiency of heating and the uniformity of temperature distribution in recycling asphalt mixtures, a pyramidal radiation heater is designed. The principles of designing horn surface size and antenna length are established according to the law of energy conservation and microwave antenna radiation theory. Modeling and simulation are carried out using IE3D software. The simulation results demonstrate that, with a fixed horn surface size, the shortened electric antenna length is the main factor leading to the improved heating uniformity. On the other hand, with a fixed antenna length and diminished surface size, the standing wave ratio decreases with the improved radiation efficiency. Furthermore, the efficiency of radiation drops with increased distance between the horn surface and the asphalt pavement. Microwave heating experiments are carried out using this type of heater. The temperature distribution of asphalt samples is obtained by the grid temperature measurement method, and Matlab simulation is performed. The experimental results are in good agreement with the simulation.
基金The Sci-Tech Achievements Transformation Program of Colleges and Universities in Jiangsu Province(No.JH09-13)the Research Fund of Nanjing Institute of Technology(No.YKJ201005)
文摘In order to study the thermoelectric efficiency of microwave heating and reproduction of asphalt pavements and the uniformity of reproduction temperature distribution, a waveguide excitation cavity is designed and applied to the structural design of a microwave heater. The structural sizes of the incentive cavities are determined based on the waveguide transmission line theory. Using IE3D software, electromagnetic simulations are respectively carried out in four different situations, including the distances between the magnetron probes （antennas） and a short-circuit board, different horn electric lengths and aperture sizes, different dielectric properties of the asphalt mixture, and the distances between the asphalt surface and the mouth cavity. The results show that, when the distance between the magnetron probe and the short-circuit board is 32.5 ram, it is the best installation site; reduction of aerial length is the main factor in improving the heating uniformity. When the aggregate is limestone, the best heating effect can be produced. Maximum radiation efficiency can be realized by adjusting the space between the heater radiation port and the asphalt pavement. The experimental results of asphalt mixture heating in four different situations have a substantial agreement with the simulation results, which confirms that the developed microwave heater can achieve better impedance matching, thus improving the quality and efficiency of heating regeneration.
基金Projects(61376076,61274026,61377024)supported by the National Natural Science Foundation of ChinaProjects(12C0108,13C321)supported by the Scientific Research Fund of Hunan Provincial Education Department,ChinaProjects(2013FJ2011,2013FJ4232)supported by the Science and Technology Plan of Hunan Province,China
文摘Metal organic chemical vapor deposition(MOCVD) is a key equipment in the manufacturing of semiconductor optoelectronic devices and microwave devices in industry. Heating system is a vital part of MOCVD. Specific heating device and thermal control technology are needed for each new reactor design. By using resistance-wire heating MOCVD reaction chamber model, thermal analysis and structure optimization of the reactor were developed from the vertical position and the distance between coils of the resistance-wire heater. It is indicated that, within a certain range, the average temperature of the graphite susceptor varies linearly with the vertical distance of heater to susceptor, and with the changed distances between the coils; furthermore, single resistance-wire heater should be placed loosely in the internal and tightly in the external. The modulate accuracy of the temperature field approximately equals the change of the average temperature corresponding to the change of the coil position.
文摘The numerous environmental protection equipments for desulfuration,denitration,and precipitation have been installed in the domestic coal-fired power plants,while the investment and energy consumption of the units increase correspondingly.To reduce the operational cost and initial investment as much as possible,the working processes of the environmental protection equipments are optimized in the design and some new technologies are adopted for energy saving.These technologies include the SCR,SNCR,combined SCR and SNCR for denitration device,system without gas-gas heater design for desulfuration,desulfuration system without bypass,booster fan and induced draft fan integrated,stack and cooling tower integrated and so on.However,such measures may cause some new problems during the operation of the equipment.The problems are summarized and analyzed thoroughly and the feasible methods are provided to solve them,which could decrease the operational risk of units.The present discussion can also improve the further design of environmental protection equipments to ensure the long-term steady operation of the units.
文摘The project has as its aim the design and implementation of the control of temperature in the cockpit of the prototype of neonatal life support equipment ESVIN based on the international standard IEC 60601-2-19 concerning the basic security and operation of the neonatal incubators. The prototype has been developed and is important because the cockpit is a new concept of medical equipment of neonatal life support. There was a modeling of the system of heating of the incubator using the concepts of system identification with the purpose of finding a mathematical model that describes the dynamic behavior of the system. Then, design and implement the strategy of feedback control with digital PID （proportional-integral-derivative） algorithm. The model allowed the design and implementation of a digital PID controller that meets in a satisfactory manner with the requirements, in accordance with the international standard. The control system implemented in the neonatal incubator ESVIN improved the effectiveness of the neonatal life support equipment in regard to temperature controller of the cockpit.
