Dynamic simulation of the helium refrigerator/liquefier for LHD

Maekawa, R.; Ooba, K.; Nobutoki, Minoru; Mito, T.

doi:10.1016/j.cryogenics.2004.10.001

Cited by 29 publications

(12 citation statements)

References 8 publications

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“…Out of different expander based cold ends, considering the trade-off between reliability and performance efficiency, EXP+JT configuration is a reasonable compromise that avoids the use of somewhat less reliable 'wet expander'. From the results obtained, it may be concluded that Config.4-1 with cold end as EXP+JT may be considered as a more acceptable configuration and many large-scale plants seen around the world today [18][19][20][21][22] have similar configurations as shown in Fig. 5. …”

Section: Trade-offs In Cold End Designmentioning

confidence: 61%

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Exergy analysis of large-scale helium liquefiers: Evaluating design trade-offs

Thomas¹,

Ghosh²,

Chowdhury³

2014

AIP Conference Proceedings

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Abstract. It is known that higher heat exchanger area, more number of expanders with higher efficiency and more involved configuration with multi-pressure compression system increase the plant efficiency of a helium liquefier. However, they involve higher capital investment and larger size. Using simulation software Aspen Hysys v 7.0 and exergy analysis as the tool of analysis, authors have attempted to identify various trade-offs while selecting the number of stages, the pressure levels in compressor, the cold-end configuration, the heat exchanger surface area, the maximum allowable pressure drop in heat exchangers, the efficiency of expanders, the parallel/series connection of expanders etc. Use of more efficient cold ends reduces the number of refrigeration stages and the size of the plant. For achieving reliability along with performance, a configuration with a combination of expander and Joule-Thomson valve is found to be a better choice for cold end. Use of multi-pressure system is relevant only when the number of refrigeration stages is more than 5. Arrangement of expanders in series reduces the number of expanders as well as the heat exchanger size with slight expense of plant efficiency. Superior heat exchanger (having less pressure drop per unit heat transfer area) results in only 5% increase of plant performance even when it has 100% higher heat exchanger surface area.

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Section: Trade-offs In Cold End Designmentioning

confidence: 61%

“…Therefore, many helium plants in operation today have configurations as those shown in Fig. 6 [19][20][21][22].…”

Section: Trade-offs In Expander Arrangementsmentioning

confidence: 99%

Exergy analysis of large-scale helium liquefiers: Evaluating design trade-offs

Thomas¹,

Ghosh²,

Chowdhury³

2014

AIP Conference Proceedings

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“…Therefore, most of existing simulators are not taking into account the real process control and cannot be used as a real-time training simulator, except the simulator of Maekawa et al (2005). The originality of PROCOS resides in the fact that it is based on the real process control architecture including the supervision system.…”

Section: Existing Cryogenic Modelling Approachesmentioning

confidence: 99%

“…To the best of the authors' knowledge, there exists only a few dynamic simulations devoted to helium cryogenic plants: • Maekawa, Ooba, Nobutoki, and Mito (2005) have simulated a 10 kW @ 4.5 K refrigerator used in a fusion experiment;…”

Section: Existing Cryogenic Modelling Approachesmentioning

confidence: 99%

A process and control simulator for large scale cryogenic plants

Bradu

Gayet

Niculescu

2009

Control Engineering Practice

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This paper presents a process and control simulator for industrial helium cryogenic plants controlled by Programmable Logic Controllers (PLC). This simulator can be used for different purposes such as operator training, test of the PLC programs or the optimization of the plant. The different component models used in the simulator are detailed and explained. Various large scale cryogenic plants used for the particle accelerator LHC (Large Hadron Collider) at CERN have been modeled and simulated. The good agreement between the simulation results and the dynamic behaviour of real plants is demonstrated with experimental results. Various discussions complete the presentation.

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“…In particular, several dynamic simulators have been proposed by [2,3,4,5,6] for operator training, dimensioning and/or control design. Based on a better dynamic modeling of the underlying process, advanced control schemes have been proposed which were often dedicated to a particular key variable.…”

Section: Introductionmentioning

confidence: 99%