在叉流板翅式换热器结构基础上,研发制作了一种粘贴型内冷却紧凑式固体除湿器,并对这种新型除湿器的性能进行实验研究.除湿器使用硅胶作为吸湿剂,通过导热胶将硅胶颗粒粘贴在除湿器主边的气流通道壁面上.实验分为4组,分别在高湿度和低...在叉流板翅式换热器结构基础上,研发制作了一种粘贴型内冷却紧凑式固体除湿器,并对这种新型除湿器的性能进行实验研究.除湿器使用硅胶作为吸湿剂,通过导热胶将硅胶颗粒粘贴在除湿器主边的气流通道壁面上.实验分为4组,分别在高湿度和低湿度环境工况下,测试本文研制的除湿器在有内冷却和无内冷却条件下的除湿运行效果以检验内冷却气流对除湿器性能的影响.实验表明,内冷却紧凑式固体除湿器工作性能优良,在除湿器有内冷却的条件下,工作周期内除湿器的平均除湿量显著提高.在高湿度条件下,硅胶在20 m in内的动态吸湿率可达12.4%,高于目前已知的常压下硅胶对水蒸汽的动态吸湿率.展开更多
The five degree freedom magnetic bearing is researched and its structure and working principles are introduced also. Based on the fuzzy control technology, combining fuzzy algorithm and PID control method, identifying...The five degree freedom magnetic bearing is researched and its structure and working principles are introduced also. Based on the fuzzy control technology, combining fuzzy algorithm and PID control method, identifying the transition process mode of the online system to get the PID parameters＇ self-adjusting, the magnetic beating system＇s Fuzzy-PID nonlinear controller is designed by analyzing the system control demands. The Fuzzy-PID nonlinear controller can deal with the magnetic bearing system＇ s open loop instability and strong nonlinearity, and the approach could improve the system＇s rapidity, adaptability, stability and dynamic characteristics. Comparative analysis and experiments are conducted between linear PID and nonlinear fuzzy- PID control methods, the results show that the fuzzy-PID controller is better, and the five-freedom magnetic bearing＇ s rotary precision experiments are conducted by the fuzzy-PID controller, it satisfies the control rotary precision demands and realizes the hearing＇s steady floating and rotating.展开更多
The performance tests were conducted on oil–water heat transfer in circumferential overlap trisection helical baffle heat exchangers with incline angles of 12°, 16°, 20°, 24° and 28°, and com...The performance tests were conducted on oil–water heat transfer in circumferential overlap trisection helical baffle heat exchangers with incline angles of 12°, 16°, 20°, 24° and 28°, and compared with a segmental baffle heat exchanger. The results show that the shell side heat transfer coefficient h_o and pressure drop Δp_o both increase while the comprehensive index h_o/Δp_o decreases with the increase of the mass flow rate of all schemes. And the shell side heat transfer coefficient, pressure drop and the comprehensive index ho/Δpo decrease with the increase of the baffle incline angle at a certain mass flow rate. The average values of shell side heat transfer coefficient and the comprehensive index h_o/Δp_o of the 12° helical baffled scheme are above 50% higher than those of the segmental one correspondingly, while the pressure drop value is very close and the ratios of the average values are about 1.664 and 1.596, respectively. The shell-side Nusselt number Nu_o and the comprehensive index Nu_o·Eu_(zo)^(-1) increase with the increase of Reynolds number of the shell side axial in all schemes, and the results also demonstrate that the small incline angled helical scheme has better comprehensive performance.展开更多
文摘在叉流板翅式换热器结构基础上,研发制作了一种粘贴型内冷却紧凑式固体除湿器,并对这种新型除湿器的性能进行实验研究.除湿器使用硅胶作为吸湿剂,通过导热胶将硅胶颗粒粘贴在除湿器主边的气流通道壁面上.实验分为4组,分别在高湿度和低湿度环境工况下,测试本文研制的除湿器在有内冷却和无内冷却条件下的除湿运行效果以检验内冷却气流对除湿器性能的影响.实验表明,内冷却紧凑式固体除湿器工作性能优良,在除湿器有内冷却的条件下,工作周期内除湿器的平均除湿量显著提高.在高湿度条件下,硅胶在20 m in内的动态吸湿率可达12.4%,高于目前已知的常压下硅胶对水蒸汽的动态吸湿率.
文摘The five degree freedom magnetic bearing is researched and its structure and working principles are introduced also. Based on the fuzzy control technology, combining fuzzy algorithm and PID control method, identifying the transition process mode of the online system to get the PID parameters＇ self-adjusting, the magnetic beating system＇s Fuzzy-PID nonlinear controller is designed by analyzing the system control demands. The Fuzzy-PID nonlinear controller can deal with the magnetic bearing system＇ s open loop instability and strong nonlinearity, and the approach could improve the system＇s rapidity, adaptability, stability and dynamic characteristics. Comparative analysis and experiments are conducted between linear PID and nonlinear fuzzy- PID control methods, the results show that the fuzzy-PID controller is better, and the five-freedom magnetic bearing＇ s rotary precision experiments are conducted by the fuzzy-PID controller, it satisfies the control rotary precision demands and realizes the hearing＇s steady floating and rotating.
基金Project(50976035)supported by the National Natural Science Foundation of ChinaProject(4521ZK120064004)supported by the Science and Technology Commission Green Energy and Power Engineering of Special Fund Project of Shanghai,China
文摘The performance tests were conducted on oil–water heat transfer in circumferential overlap trisection helical baffle heat exchangers with incline angles of 12°, 16°, 20°, 24° and 28°, and compared with a segmental baffle heat exchanger. The results show that the shell side heat transfer coefficient h_o and pressure drop Δp_o both increase while the comprehensive index h_o/Δp_o decreases with the increase of the mass flow rate of all schemes. And the shell side heat transfer coefficient, pressure drop and the comprehensive index ho/Δpo decrease with the increase of the baffle incline angle at a certain mass flow rate. The average values of shell side heat transfer coefficient and the comprehensive index h_o/Δp_o of the 12° helical baffled scheme are above 50% higher than those of the segmental one correspondingly, while the pressure drop value is very close and the ratios of the average values are about 1.664 and 1.596, respectively. The shell-side Nusselt number Nu_o and the comprehensive index Nu_o·Eu_(zo)^(-1) increase with the increase of Reynolds number of the shell side axial in all schemes, and the results also demonstrate that the small incline angled helical scheme has better comprehensive performance.
