Purification processes are widely used in hydrogen networks of refineries to increase hydrogen reuse. In refineries, hydrogen purification techniques include hydrocarbon, hydrogen sulfide and CO removal units. In addi...Purification processes are widely used in hydrogen networks of refineries to increase hydrogen reuse. In refineries, hydrogen purification techniques include hydrocarbon, hydrogen sulfide and CO removal units. In addition, light hydrocarbon recovery from the hydrogen source streams can also result in hydrogen purification. In order to simplify the superstructure and mathematical model of hydrogen network integration, the models of different purification processes are unified in this paper, including mass balance and the expressions for hydrogen recovery and impurity removal ratios, which are given for all the purification units in refineries. Based on the proposed unified model, a superstructure of hydrogen networks with purification processes is constructed.展开更多
The purpose of this study is to use magnetic field of 50/60 Hz up to 0.2 mT for energy source. This paper focuses on magnetic energy harvesting from electrical appliances which can be also used for power consumption m...The purpose of this study is to use magnetic field of 50/60 Hz up to 0.2 mT for energy source. This paper focuses on magnetic energy harvesting from electrical appliances which can be also used for power consumption monitoring. The magnetic energy harvesting device consists of an energy harvesting module, Cockcroft-Walton circuit and storage capacitor. First of all, typical magnetic fields around several electrical appliances are investigated. In order to harvest 10 mJ energy, the shape of magnetic flux concentration flange in energy harvesting module and number of steps in Cockcroft-Walton circuit are considered. From experimental results, magnetic energy harvesting of 17 mJ from a refrigerator is successfully demonstrated.展开更多
We previously devised a new type of portable hydraulic turbine that uses the kinetic energy of an open-channel flow to improve output power by catching and accelerating the flow. The turbine contains an axial flow run...We previously devised a new type of portable hydraulic turbine that uses the kinetic energy of an open-channel flow to improve output power by catching and accelerating the flow. The turbine contains an axial flow runner with an appended collection device and a diffuser section that is not axisymmetric. The objective of this study is to determine how interference between the collection device and the runner influences performance characteristics of the turbine. We investigated the performance characteristics of the turbine and flow field for different numbers of blades during both unsteady and steady flow. During an unsteady flow, the maximum values of power coefficients for three and two blades increased by approximately 8.8% and 21.4%, respectively, compared to those during a steady flow. For the three-blade runner, the power coefficient showed small fluctuations, but for the two-blade runner, the power coefficient showed large fluctuations. These fluctuations in the power coefficient are attributed to fluctuations in the loading coefficient, which were generated by interference between the runner and the diffuser section of the collection device.展开更多
基金Supported by the National Basic Research Program of China(2012CB720500)the National Natural Science Foundation of China(21276204,20936004)
文摘Purification processes are widely used in hydrogen networks of refineries to increase hydrogen reuse. In refineries, hydrogen purification techniques include hydrocarbon, hydrogen sulfide and CO removal units. In addition, light hydrocarbon recovery from the hydrogen source streams can also result in hydrogen purification. In order to simplify the superstructure and mathematical model of hydrogen network integration, the models of different purification processes are unified in this paper, including mass balance and the expressions for hydrogen recovery and impurity removal ratios, which are given for all the purification units in refineries. Based on the proposed unified model, a superstructure of hydrogen networks with purification processes is constructed.
文摘The purpose of this study is to use magnetic field of 50/60 Hz up to 0.2 mT for energy source. This paper focuses on magnetic energy harvesting from electrical appliances which can be also used for power consumption monitoring. The magnetic energy harvesting device consists of an energy harvesting module, Cockcroft-Walton circuit and storage capacitor. First of all, typical magnetic fields around several electrical appliances are investigated. In order to harvest 10 mJ energy, the shape of magnetic flux concentration flange in energy harvesting module and number of steps in Cockcroft-Walton circuit are considered. From experimental results, magnetic energy harvesting of 17 mJ from a refrigerator is successfully demonstrated.
文摘We previously devised a new type of portable hydraulic turbine that uses the kinetic energy of an open-channel flow to improve output power by catching and accelerating the flow. The turbine contains an axial flow runner with an appended collection device and a diffuser section that is not axisymmetric. The objective of this study is to determine how interference between the collection device and the runner influences performance characteristics of the turbine. We investigated the performance characteristics of the turbine and flow field for different numbers of blades during both unsteady and steady flow. During an unsteady flow, the maximum values of power coefficients for three and two blades increased by approximately 8.8% and 21.4%, respectively, compared to those during a steady flow. For the three-blade runner, the power coefficient showed small fluctuations, but for the two-blade runner, the power coefficient showed large fluctuations. These fluctuations in the power coefficient are attributed to fluctuations in the loading coefficient, which were generated by interference between the runner and the diffuser section of the collection device.
