Experimental investigation of 4.2 K high efficiency G-M refrigerators

2014 ◽  
Author(s):  
X. H. Hao ◽  
S. H. Yao
Keyword(s):  
Experimental Investigation ◽  
High Efficiency

scholarly journals TURBOVENTILIATORIŲ, VEIKIANČIŲ BE VĖJO SRAUTO, EKSPERIMENTINIS TYRIMAS / EXPERIMENTAL INVESTIGATION OF TURBOVENTILATORS OPERATING WITHOUT WIND FLOW

2018 ◽  
Vol 10 (0) ◽  
pp. 1-5
Author(s):  
Dovydas Rimdžius ◽  
Juozas Bielskus
Keyword(s):  
Experimental Investigation ◽  
Energy Demand ◽  
High Efficiency ◽  
Normal Operation ◽  
Wind Flow ◽  
Wind Speeds ◽  
Energy Technologies ◽  
Operation Conditions ◽  
Low Wind Speeds ◽  
Ventilation Systems

Fans used in modern buildings ventilation systems make up a large part of the building‘s total energy demand. In order to ensure proper air quality and high efficiency of ventilation systems, it is necessary to search new solutions. One of the possible ways is to use renewable energy technologies. Currently it is a widespread use of wind energy in turboventilators. Major part of previous researches are related to tests of different construction turboventilators, determination of their characteristics and analysis of results. However, assessment of the current researches situation indicates the lack of fundamental researches of air flows interaction processes impact to turboventilators efficiency. In addition, researchers on hybrid turboventilators still search for solutions to increase the ventilation functionality when there is not enough wind power for operation of these devices. In order to determine the significance of these processes in more detail, in the present study, two different types of turboventilators are experimentally tested in two different ways. In one case, their rotors are rotated by an additional source of energy, in another case they are tested under different wind speed conditions. The aim of research is to assess not only the characteristics of the testes devices under normal conditions, but also their ventilation potential without wind flow. The results of experimental investigation showed that under normal operation conditions of the device, a large part of the extracted air flow is impacted by rotor rotation and ejection phenomenon. Empirical equations and investigation results presented in the paper can be useful for comparing other experiments and improving the functionality of the device at low wind speeds. Santrauka Šiuolaikinių pastatų vėdinimo sistemose naudojami ventiliatoriai sudaro didelę dalį pastato bendrojo energijos poreikio. Siekiant užtikrinti tinkamą oro kokybę ir aukštą vėdinimo sistemų efektyvumą, būtina ieškoti naujų sprendimų. Vienas iš galimų būdų – atsinaujinančią energiją naudojančių technologijų taikymas. Šiuo metu plačiai paplitęs būdas naudoti vėjo energiją turboventiliatoriuose. Didžioji dalis ankstesniuose moksliniuose tyrimuose atliktų eksperimentų susiję su skirtingų konstrukcijų turboventiliatorių bandymais, jų charakteristikų nustatymu ir rezultatų palyginimu. Visgi, vertinant esamą mokslinių tyrimų situaciją, pastebima, jog trūksta fundamentalių tyrimų nagrinėjant oro srautų sąveikos procesų įtaką turboventiliatorių efektyvumui. Be to, atliekamuose tyrimuose su hibridiniais tokio tipo įrenginiais tebeieškoma sprendimų, kaip padidinti vėdinimo funkcionalumą, kai nepakanka vėjo srauto įrenginiui veikti. Siekiant detaliau nustatyti minėtų procesų svarbą, pristatomame tyrime dviem skirtingais metodais eksperimentiškai bandomi du skirtingo tipo turboventiliatoriai. Vienu atveju jų rotoriai sukami papildomu energijos šaltiniu, kitu atveju bandomi skirtingomis vėjo greičių sąlygomis. Tyrimų metu siekiama įvertinti ne tik bandomų įrenginių charakteristikas veikiant įprastomis sąlygomis, bet ir jų vėdinimo potencialą be vėjo srauto. Eksperimentinių tyrimų rezultatai parodė, jog įrenginiui veikiant įprastomis sąlygomis didelė dalis ištraukiamojo oro srauto veikiama rotorių sukimosi bei ežekcijos reiškinio. Straipsnyje pateiktos empirinės lygtys ir tyrimo rezultatai gali būti naudingi lyginant kitus eksperimentus bei tobulinant įrenginio funkcionalumą esant mažam vėjo greičiui.

Theoretical and Experimental Investigation for Some Basic Physical Phenomena of Centrifugal Compressors

1986 ◽  
Author(s):  
Wang Qinghuan
Keyword(s):  
Experimental Investigation ◽  
Centrifugal Compressor ◽  
High Efficiency ◽  
Great Success ◽  
Centrifugal Compressors ◽  
Performance Map ◽  
Physical Phenomena

Based on a series of theoretical and experimental investigation, this paper presents several fundamental views on some basic physical phenomena of centrifugal compressors, such as choking flow, surge characteristics, matching of impeller and diffuser, the position of high-efficiency region on the performance map, etc. A prototype centrifugal compressor for a marine turbocharger series has been designed according to the principles discussed in this paper. It was a great success and has been put into production.

Experimental investigation on high-efficiency grinding of Inconel 718 with heat pipe grinding wheel

2017 ◽  
Vol 21 (1) ◽  
pp. 86-102 ◽  
Author(s):  
Jiajia Chen ◽  
Yucan Fu ◽  
Qingshan He ◽  
Yanbin Zhu ◽  
Wei Zhang
Keyword(s):  
Experimental Investigation ◽  
Heat Pipe ◽  
Inconel 718 ◽  
High Efficiency ◽  
Grinding Wheel

scholarly journals Experimental Investigation on Atomization and Dustfall Characteristics of Combined Nozzles for Shearer External Spray in Fully Mechanized Coal Mining Face

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Qian Wang ◽  
Ruixin Song ◽  
Junpeng Wang ◽  
Cuicui Xu ◽  
Gang Zhou ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Coal Mining ◽  
High Efficiency ◽  
Field Application ◽  
Respirable Dust ◽  
Optimal Parameters ◽  
Angle Change ◽  
Phase Doppler Interferometry ◽  
Mining Face

To explore the dustfall effect of combined nozzles used in a fully mechanized mining face, Phase Doppler Interferometry (PDI) system was used to test 6 types of high-efficiency atomizer under 8 MPa. A new nozzle group of nozzles 2#, 3#, and 5# is selected by atomization experiment. The atomization experiment and field application test of the preferred nozzle are performed. The experiment and field application results show that, with the spray pressure of 8 MPa, when the distance in the nozzle group is 200 mm and the angle change is 10 degrees, the atomization effect is the best. Under the optimal parameters, the average dustfall rates of the entire and respirable dust are 81.82% and 79.96%, respectively, which are 23.49% and 20.75% higher than those of the traditional shearer.

Theoretical and Experimental Investigation of a 10-kW High-Efficiency 1070-nm Fiber Amplifier

2020 ◽  
Vol 47 (10) ◽  
pp. 1006001
Author(s):  
陈晓龙 Chen Xiaolong ◽  
何宇 He Yu ◽  
徐中巍 Xu Zhongwei ◽  
郭晓晨 Guo Xiaochen ◽  
叶韧 Ye Ren ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
High Efficiency ◽  
Fiber Amplifier
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