Progress has been developed in harvesting lowfrequency and irregular blue energy using a triboelectric–electromagnetic hybrid generator in recent years. However,the design of the high-efficiency, mechanically durable...Progress has been developed in harvesting lowfrequency and irregular blue energy using a triboelectric–electromagnetic hybrid generator in recent years. However,the design of the high-efficiency, mechanically durable hybrid structure is still challenging. In this study, we report a fully packaged triboelectric–electromagnetic hybrid generator(TEHG), in which magnets were utilized as the trigger to drive contact–separation-mode triboelectric nanogenerators(CS-TENGs) and coupled with copper coils to operate rotary freestanding-mode electromagnetic generators(RF-EMGs). The magnet pairs that produce attraction were used to transfer the external mechanical energy to the CS-TENGs, and packaging of the CS-TENGpart was achieved to protect it from the ambient environment. Under a rotatory speed of 100 rpm, the CS-TENGs enabled the TEHG to deliver an output voltage, current,and average power of 315.8 V, 44.6 μA, and ~ 90.7 μW,and the output of the RF-EMGs was 0.59 V, 1.78 m A, and 79.6 μW, respectively. The cylinder-like structure made the TEHG more easily driven by water flow and demonstrated to work as a practical power source to charge commercial capacitors. It can charge a 33μF capacitor from 0 to 2.1 V in 84 s, and the stored energy in the capacitor can drive an electronic thermometer and form a self-powered water-temperature sensing system.展开更多
为探索水泵流量对整车冷却系统的影响,建立发动机GT-POWER模型和整车冷却系统GT-COOL模型,同时利用试验验证模型的准确性,并求取发动机热边界条件和散热器换热特性参数。建立散热器三维几何模型,利用CFD方法求取散热器的流动特性参数,...为探索水泵流量对整车冷却系统的影响,建立发动机GT-POWER模型和整车冷却系统GT-COOL模型,同时利用试验验证模型的准确性,并求取发动机热边界条件和散热器换热特性参数。建立散热器三维几何模型,利用CFD方法求取散热器的流动特性参数,将发动机模型和散热器模型在STAR-CCM+中耦合成一个系统,模拟整车冷却系统的工作过程。以某农用车的冷却系统为例,通过仿真求得其水泵流量在0.8 kg/s时散热器散热功率达到最大值10.489 k W,且发动机燃烧室壁面温度为523 K,较为合理。展开更多
The majority of research on water turbines focuses on design improvement of large-scale hydrokinetic turbines for power generation, which may have delayed the utilization of kinetic energy contained in rivers and cana...The majority of research on water turbines focuses on design improvement of large-scale hydrokinetic turbines for power generation, which may have delayed the utilization of kinetic energy contained in rivers and canals. The aim of this paper is to improve the efficiency of a two bladed Savonius type cross-flow hydrokinetic turbine, which can be used as an energy converter to harness free-stream kinetic energy of water. An impinging jet duct design is presented for improving performance of the Savonius turbine in wind application as seen from literature. The performance of the modified turbine is evaluated using CFD software Fluent, and is compared with that of a simple two bladed Savonius water turbine and some of the prominent literature designs of the Savonius turbine. It is shown that the present design exhibits improved performance compared to the selected designs of the Savonius turbine.Further an insight of the improved performance of the modified turbine is also obtained from flow physics study.展开更多
In the coal fired power station, the regulation of the load or the sudden stop operation of the unit in accident may result in water hammer, which would have critical influence on the safety operation of the unit. In ...In the coal fired power station, the regulation of the load or the sudden stop operation of the unit in accident may result in water hammer, which would have critical influence on the safety operation of the unit. In this paper the analysis of water dynamic characters and the calculation of the pressure increment were shown, when the water hammer was produced in the system.展开更多
Application of CuO-water nanofluid with size of the nanoparticles of 20 nm and volume concentrations up 2% is numerically investigated in a radiator of Chevrolet Suburban diesel engine under turbulent flow conditions....Application of CuO-water nanofluid with size of the nanoparticles of 20 nm and volume concentrations up 2% is numerically investigated in a radiator of Chevrolet Suburban diesel engine under turbulent flow conditions. The heat transfer relations between airflow and nanofluid coolant have been obtained to evaluate local convective and overall heat transfer coefficients and also pumping power for nanofluid flowing in the radiator with a given heat exchange capacity. In the present study, the effects of the automotive speed and Reynolds number of the nanofluid in the different volume concentrations on the radiator performance are also investigated. The results show that for CuO-water nanofluid at 2% volume concentration circulating through the flat tubes with Renf = 6000 while the automotive speed is 70 km/hr, the overall heat transfer coefficient and pumping power are approximately 10% and 23.8% more than that of base fluid for given conditions, respectively.展开更多
Neutral beam injection heating is one of the main auxiliary heating methods in controllable nuclear fusion research. In the EAST neutral beam injector, a water flow calorimetry （WFC） system is applied to measure the...Neutral beam injection heating is one of the main auxiliary heating methods in controllable nuclear fusion research. In the EAST neutral beam injector, a water flow calorimetry （WFC） system is applied to measure the heat load on the electrode system of the ion source and the heat loading components of the beamline. Due to the heat loss in the return water pipe, there are some measuring errors for the current WFC system. In this paper, the errors were measured experimentally and analyzed theoretically, which lay a basis for the exact calculation of beam power deposition distribution and neutralization efficiency.展开更多
This paper is concerned with water saving for water-loop cooling tower system in power plants. A newly developed water saving device of swirling flow is presented. The key point is that the new water saving device mak...This paper is concerned with water saving for water-loop cooling tower system in power plants. A newly developed water saving device of swirling flow is presented. The key point is that the new water saving device makes the steam swirl up along the device wall rather than engender laminar flow in a corrugated plate. The corrugated plate device can save approximately 10 percent of the total lost water. In contrast to the scale model of corrugated plate water saving device, experimental analyses have demonstrated that the new water saving device of swirling flow is more efficient, with a capacity of saving more than 20 percent of water.展开更多
基金funded by Natural Science Foundation of China (NSFC) (Grant No. U1432249)the National Key R&D Program of China (Grant 2017YFA0205002)+5 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)supported by Collaborative Innovation Center of Suzhou Nano Science & Technologythe support from China Postdoctoral Science Foundation (2017M610346)Natural Science Foundation of Jiangsu Province of China (BK20170343)Nantong Municipal Science and Technology Programthe support from Jiangsu University National Science Research Program (16KJB110021)
文摘Progress has been developed in harvesting lowfrequency and irregular blue energy using a triboelectric–electromagnetic hybrid generator in recent years. However,the design of the high-efficiency, mechanically durable hybrid structure is still challenging. In this study, we report a fully packaged triboelectric–electromagnetic hybrid generator(TEHG), in which magnets were utilized as the trigger to drive contact–separation-mode triboelectric nanogenerators(CS-TENGs) and coupled with copper coils to operate rotary freestanding-mode electromagnetic generators(RF-EMGs). The magnet pairs that produce attraction were used to transfer the external mechanical energy to the CS-TENGs, and packaging of the CS-TENGpart was achieved to protect it from the ambient environment. Under a rotatory speed of 100 rpm, the CS-TENGs enabled the TEHG to deliver an output voltage, current,and average power of 315.8 V, 44.6 μA, and ~ 90.7 μW,and the output of the RF-EMGs was 0.59 V, 1.78 m A, and 79.6 μW, respectively. The cylinder-like structure made the TEHG more easily driven by water flow and demonstrated to work as a practical power source to charge commercial capacitors. It can charge a 33μF capacitor from 0 to 2.1 V in 84 s, and the stored energy in the capacitor can drive an electronic thermometer and form a self-powered water-temperature sensing system.
文摘为探索水泵流量对整车冷却系统的影响,建立发动机GT-POWER模型和整车冷却系统GT-COOL模型,同时利用试验验证模型的准确性,并求取发动机热边界条件和散热器换热特性参数。建立散热器三维几何模型,利用CFD方法求取散热器的流动特性参数,将发动机模型和散热器模型在STAR-CCM+中耦合成一个系统,模拟整车冷却系统的工作过程。以某农用车的冷却系统为例,通过仿真求得其水泵流量在0.8 kg/s时散热器散热功率达到最大值10.489 k W,且发动机燃烧室壁面温度为523 K,较为合理。
文摘The majority of research on water turbines focuses on design improvement of large-scale hydrokinetic turbines for power generation, which may have delayed the utilization of kinetic energy contained in rivers and canals. The aim of this paper is to improve the efficiency of a two bladed Savonius type cross-flow hydrokinetic turbine, which can be used as an energy converter to harness free-stream kinetic energy of water. An impinging jet duct design is presented for improving performance of the Savonius turbine in wind application as seen from literature. The performance of the modified turbine is evaluated using CFD software Fluent, and is compared with that of a simple two bladed Savonius water turbine and some of the prominent literature designs of the Savonius turbine. It is shown that the present design exhibits improved performance compared to the selected designs of the Savonius turbine.Further an insight of the improved performance of the modified turbine is also obtained from flow physics study.
文摘In the coal fired power station, the regulation of the load or the sudden stop operation of the unit in accident may result in water hammer, which would have critical influence on the safety operation of the unit. In this paper the analysis of water dynamic characters and the calculation of the pressure increment were shown, when the water hammer was produced in the system.
文摘Application of CuO-water nanofluid with size of the nanoparticles of 20 nm and volume concentrations up 2% is numerically investigated in a radiator of Chevrolet Suburban diesel engine under turbulent flow conditions. The heat transfer relations between airflow and nanofluid coolant have been obtained to evaluate local convective and overall heat transfer coefficients and also pumping power for nanofluid flowing in the radiator with a given heat exchange capacity. In the present study, the effects of the automotive speed and Reynolds number of the nanofluid in the different volume concentrations on the radiator performance are also investigated. The results show that for CuO-water nanofluid at 2% volume concentration circulating through the flat tubes with Renf = 6000 while the automotive speed is 70 km/hr, the overall heat transfer coefficient and pumping power are approximately 10% and 23.8% more than that of base fluid for given conditions, respectively.
基金supported by the National Magnetic Confinement Fusion Science Program of China(No.2013GB101001)the International Science&Technology Cooperation Program of China(No.2014DFG61950)
文摘Neutral beam injection heating is one of the main auxiliary heating methods in controllable nuclear fusion research. In the EAST neutral beam injector, a water flow calorimetry （WFC） system is applied to measure the heat load on the electrode system of the ion source and the heat loading components of the beamline. Due to the heat loss in the return water pipe, there are some measuring errors for the current WFC system. In this paper, the errors were measured experimentally and analyzed theoretically, which lay a basis for the exact calculation of beam power deposition distribution and neutralization efficiency.
文摘This paper is concerned with water saving for water-loop cooling tower system in power plants. A newly developed water saving device of swirling flow is presented. The key point is that the new water saving device makes the steam swirl up along the device wall rather than engender laminar flow in a corrugated plate. The corrugated plate device can save approximately 10 percent of the total lost water. In contrast to the scale model of corrugated plate water saving device, experimental analyses have demonstrated that the new water saving device of swirling flow is more efficient, with a capacity of saving more than 20 percent of water.
