Dynamic gas bearing turbine technology in hydrogen plants

Abstract

Dynamic Gas Bearing Turbines -although applied for helium refrigerators and liquefiers for decades -experienced limitations for hydrogen applications due to restrictions in axial bearing capacity. With a new design concept for gas bearing turbines developed in 2004, axial bearing capacity was significantly improved enabling the transfer of this technology to hydrogen liquefiers. Prior to roll-out of the technology to industrial plants, the turbine bearing technology passed numerous tests in R&D test benches and subsequently proved industrial scale demonstration at Linde Gas' hydrogen liquefier in Leuna, Germany. Since its installation, this turbine has gathered more than 16,000 successful operating hours and has outperformed its oil bearing brother in terms of performance, maintainability as well as reliability.The present paper is based on Linde Kryotechnik AG's paper published in the proceedings of the CEC 2009 concerning the application of Dynamic Gas Bearing Turbines in hydrogen applications. In contrast to the former paper, this publication focuses on the steps towards final market launch and more specifically on the financial benefits of this turbine technology, both in terms of capital investment as well as operating expenses.

Cycle Design of Reverse Brayton Cryocooler for HTS Cable Cooling Using Exergy Analysis

“…The complete thermodynamic properties of helium at the proposed designed condition are listed in TABLE 2, and the corresponding temperature-entropy diagram is shown in Figure 6. Table 2: Thermodynamic properties of helium for designed cycle Figure 6: Designed Brayton-cycle cryocooler on temperature-entropy diagram of helium Gas bearing turbo expander system is selected for this cycle as it gives stable performance and runs a system for the longer time [7]. Ghosh [8] has described a procedure to obtain the parameter such as diameter of wheel and specific speed of turbine.…”

Hydrogen liquefaction: a review of the fundamental physics, engineering practice and future opportunities

“…255 Oil-bearing and gas-bearing turbine technologies are considered state-of-the-art for hydrogen liquefiers. 126,256 Oilbearing systems require a continuous oil supply, oil pumps, and additional infrastructure for safe shutdown in the case of cycle failure. 192 This additional equipment and power requirement increases their capital and operational expenditure above those of gas-bearing turbines.…”

“…These include BOG generation due to depressurisation (flashing), heat ingress into transfer pipes, heat added by equipment such as pumps, and cooling down of LH 2 carrying vessels. For future large-scale LH 2 storage and transport applications involving land-based tanks and Table 7 Summary of challenges across the hydrogen liquefaction process 126,169,174,192,202,245,246,256 Energy & Environmental Science Review sea-borne vessels, the management of such BOG is crucial from both an economic and safety perspective.…”

A Review of Grooved Dynamic Gas Bearings

“…GBs often utilize gas lubricant that originates directly from the working gas processed by the rotating machine. The gaseous lubricant can either be operated under ideal gas conditions such as in air cycle machines [4] or gas processing [5] or close to the saturation line such as in heat pumps or chillers [6]. In dynamic bearings, no auxiliaries are needed, and the machines can easily be conceived as hermetic units, thus avoiding the need for complicated seals to prevent leakage.…”