Line Chilldown

Line Chilldown Using Liquid Hydrogen and Liquid Nitrogen

This validation case compares SINDA/FLUINT and FloCAD® predictions with a 1966 test by the National Bureau of Standards (NBS, now National Institute of Standards and Technology, NIST). In the NBS tests, a pressurized dewar containing either LN2 or LH2 was isolated from an empty 200ft (61m) line (open to the atmosphere) by a valve. At time zero, the valve between the dewar and the line was opened, and cryogenic liquid was allowed to flow until the line was completely full and liquid was discharged from open end of the pipe.

Test Set-up

Comparison with Test Data

Liquid (Normal) Hydrogen, Comparison with Figure 7

Differences between parahydrogen and normal hydrogen are explored, since the exact composition of the hydrogen is unknown. The importance of uncertainties in heat transfer and pressure drop correlations, copper alloy properties (also unknown), dewar pressure, and even the roughness and manufacturing tolerance of the tubing is explored. This study demonstrates automated calibration to test data, and investigation of sensitivities.

Click here to fetch the Cryogenic Cooldown Validation from our User Forum

Download the full Line Chilldown Validation report

See also LNG chilldown of a flexible composite hose

Vapor Compression Cycles

Tuesday March 10th, 2pm MST

This webinar explains how the toolbox approach of Thermal Desktop and FloCAD can be used to design and simulate vapor compression cycles at various levels of detail. Applications include heat pumps, automotive climate control, and refrigeration systems.

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Working Fluid Mixtures

Thursday March 12th, 2pm MST

Working fluid mixtures can be as simple as air and water. Or as complex as ... well, air and water.

"Air" might be a simple perfect gas or a collection of real gases ... itself a mixture. "Water" might be a simple nonvolatile approximation of liquid water, or it might be a volatile liquid.

This webinar discusses mixture types, and repercussions such as pressure and temperature range limits. It illustrates both how to set initial conditions and how to determine what is going on in results.

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