Conveners
C2PoB - Expanders I
- Yatming Than (BNL)
- Kenichi Sato (Japan Science and Technology Agency)
Abstract：In the start-stop phase, the foil in the gas foil bearing and the shaft are in a dry friction state. The solid lubricating coating on the foil and rotor has a crucial effect on bearing‘s using life. The friction and wear characteristics of several coating materials， like molybdenum disulfide, aluminum oxide, dense Cr, polyamide，were tested on the friction and wear test rig. The...
The numerical simulation included solid blades with four different leading-edge thicknesses and four different leading-edge geometries. One of the geometries was square, one was ellipse a(ellipse ratio is 1), one was ellipse b(ellipse ratio is 2), and the other was ellipse c(ellipse ratio is 3). The four thicknesses were 0.7mm, 0.6mm, 0.5mm, 0.4mm. The results show increased efficiency loss...
An extensive experimental program has been carried out on a 22 mm tip diameter radial-axial flow cryogenic turboexpander, in order to directly compare performance characteristics by varying the vaneless space. A reference nozzle with radial clearance 0.5 mm was used in the refrigeration system, and seven other nozzles were designed with radial clearance of 0.1 mm, 0.2 mm, 0.8 mm, 1.0 mm, 1.2mm...
Turbo-expander is the core machinery of the helium refrigerator. Bearing as the supporting element is the core technology to impact the design of turbo-expander. The perfect design and performance study for the gas bearing are the premise to ensure the stability of turbo-expander. In this paper, numerical simulation is used to analyze the performance of gas bearing for a 500W helium...
Most modern medium and large capacity helium liquefaction/refrigeration plants employ high speed cryogenic turboexpanders in their refrigeration/liquefaction cycles as active cooling devices. The operating speed of these turboexpanders is in the range of 3000-5000 Hz and hence specialized types of bearings are required. Floating pad journal bearing, which is a special type of tilting pad...
Coal-bed methane (CBM) reserves are rich in Sinkiang of China, and liquefaction is a critical step for the CBM exploration and utilization. Different from other CBM gas fields in China, CBM distribution in Sinkiang is widespread but scattered, and the pressure, flow-rate and nitrogen content of CBM feed vary significantly. The skid-mounted liquefaction device is suggested as an efficient and...
