期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
流体/半流体物料连续流射频加热辅助装置设计与试验
1
作者 张浩 仵明太 +2 位作者 张一鸣 王绍金 令博 《农业工程学报》 EI CAS CSCD 北大核心 2024年第19期33-41,共9页
针对流体/半流体物料在流动状态下开展射频杀菌、钝酶、提取时加热不均匀的问题,该研究设计了一套适用于英国Strayfield SO6B型射频加热系统的流体/半流体物料连续流辅助装置。该装置主要由蠕动泵、电动机、料槽和控制系统等组成,料槽... 针对流体/半流体物料在流动状态下开展射频杀菌、钝酶、提取时加热不均匀的问题,该研究设计了一套适用于英国Strayfield SO6B型射频加热系统的流体/半流体物料连续流辅助装置。该装置主要由蠕动泵、电动机、料槽和控制系统等组成,料槽内部装有一组剪切折叠满面式螺旋桨实现对物料的混合搅拌。选取生牛乳、羧甲基纤维素(carboxymethylcellulose,CMC)溶液以及苹果渣-柠檬酸混合溶液(PS)3种物料分别进行射频处理,结果显示,相同条件下3种物料的升温速率从大到小依次为生牛乳、CMC溶液、PS,且在20 min内所有物料即可达到目标温度,证实该装置可以辅助不同特性流体/半流体物料实现射频连续均匀加热。与无螺旋搅拌相比,在物料静止状态,螺旋搅拌可以改善射频加热均匀性,其中CMC溶液改善最为明显,其射频加热均匀性指数由0.139降为0.068;在物料流动状态,螺旋搅拌可以改善CMC溶液与果渣粒径为5 mm的苹果渣-柠檬酸混合溶液(PS5)的加热均匀性,CMC溶液和果渣粒径PS5的最大温差分别下降了13.4和11.4℃,但在低速搅拌时固液混合物料易因颗粒漂浮而降低加热均匀性。整体来看,该装置可以实现流体/半流体物料的射频连续均匀化处理,可为该类物料的射频连续化加热及工业化处理提供技术与理论支持。 展开更多
关键词 射频 连续流 流体/半流体 加热均匀性 辅助装置
下载PDF
Optimal selection of annulus radius ratio to enhance heat transfer with minimum entropy generation in developing laminar forced convection of water-Al2O3 nanofluid flow 被引量:23
2
作者 Siavashi Majid Jamali Mohammad 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第8期1850-1865,共16页
Heat transfer and entropy generation of developing laminar forced convection flow of water-Al_2O_3 nanofluid in a concentric annulus with constant heat flux on the walls is investigated numerically. In order to determ... Heat transfer and entropy generation of developing laminar forced convection flow of water-Al_2O_3 nanofluid in a concentric annulus with constant heat flux on the walls is investigated numerically. In order to determine entropy generation of fully developed flow, two approaches are employed and it is shown that only one of these methods can provide appropriate results for flow inside annuli. The effects of concentration of nanoparticles, Reynolds number and thermal boundaries on heat transfer enhancement and entropy generation of developing laminar flow inside annuli with different radius ratios and same cross sectional areas are studied. The results show that radius ratio is a very important decision parameter of an annular heat exchanger such that in each Re, there is an optimum radius ratio to maximize Nu and minimize entropy generation. Moreover, the effect of nanoparticles concentration on heat transfer enhancement and minimizing entropy generation is stronger at higher Reynolds. 展开更多
关键词 nanofluid heat transfer enhancement forced convection entropy generation annulus radius ratio
下载PDF
A new dimmer for alternating-current directly driven light-emitting-diode lamp 被引量:1
3
作者 KIM Jong-hyun RYU Myung-hyo +1 位作者 YOON Hyok-min SONG Eui-ho 《Journal of Central South University》 SCIE EI CAS 2012年第2期374-379,共6页
A new dimmer using a mental-oxide-semiconductor field-effect transistor (MOSFET) for alternating-current (AC) directly driven light-emitting-diode (LED) lamp was presented. The control method of proposed dimmer is pul... A new dimmer using a mental-oxide-semiconductor field-effect transistor (MOSFET) for alternating-current (AC) directly driven light-emitting-diode (LED) lamp was presented. The control method of proposed dimmer is pulse width control (PWM) method. Compared with the conventional phase-controlled dimmer, the proposed PWM dimmer can produce sine wave and did not cause harmonics problem. Furthermore, the proposed control method did not amplify the light flicker due to the independence of input voltage. Therefore, the PWM dimmer can be used as the dimmer of the AC LED lamp instead of the conventional phase-controlled dimmer. The experimental result shows that the proposed PWM dimmer has good performances. 展开更多
关键词 alternating-current directly driven light-emitting-diode pulse width control total harmonic distortion flicker triac
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部