Cryme Facility, Water facility test section during PIV and LIF experiments / optical setup for visualization

The “CryME” (Cryogenic Microgravity Experiments) facility is a fully customized cryostat, for the characterization of cryogenic sloshing, boiling and thermal stratifi cation on earth and in microgravity conditions at temperature down to 70 K. The presence of large windows allows the use of non-intrusive optical techniques such as particle image velocimetry or high-speed visualization.

The cryostat is schematically composed by three areas:

- An evacuated space, which provide high thermal insulation of the inner parts;

- An LN2 reservoir, which pressure is properly defi ne to obtain the LN2 temperature between 70 and 77 K;

- The sample area, surrounded by GHe, at temperature selected between 70 and 77 K.

The cryostat has been designed with a large internal sample area providing isothermal condition, with very high temperature uniformity. Different cells can be placed inside the cryostat to perform scientific experiments.

“CryoLine“ is a large multipurpose facility, which allows the characterization of cryogenic valves and the study of cryogenic water hammer and chill-down phenomena. The CryoLine facility can be placed horizontally, vertically and at intermediate angles to study the effect of gravity direction on cryogenic two-phase fl ows. Characterization of Cryogenic two-phase flow is performed using non-intrusive measurement technique, such as high speed and high-resolution visualization. The facility is equipped with a reservoir of about 600 liters to store Liquid Nitrogen at an adjustable pressure from 1 to 20 bars allowing a maximum flow rate of 1.2 l/s. An on/off control valve allows to prime or to stop the flow of LN2 from the reservoir to the rest of the facility. The whole installation is certified.

The measurements section is composed by:

- A stainless steel pipeline, housing the selected element, and flush mounted measurement sensors (temperature and pressure sensors)

- Vacuum chamber (1.7mm x 0.7m x 0.7 m), surrounding the line offering a thermal insulation of all its elements.

The chamber is provided of optical access (quartz windows).

The facility allows measurement of temperature, pressure, flow rate and visualization of the fl ow (single phase or two-phase ) during transient and at steady state.

The flow rate is measured by means of a Coriolis fl owmeter, while the temperature and pressure sensors are placed in a VKI customized plugin module. The pressure transducers are screwed on the module in four points around the circumference of the inner pipe. The temperature sensor housing requires, instead, a cap that flush-mounts the sensor on the line.

The pressure transducers are Cryogenic Miniature ruggedized CTL-190 M series (Kulite France). The sensible tip has a four arm Wheatstone bridge as measuring principle, vacuum referred. The temperature transducers are Resistant Temperature Detector (RTD) Cernox CX-1050-AA-HT-1.4L (Lake Shore Cryotronics, Inc).

CryoLine Facility, vertical position

Cryogenic Water Hammer

CryoLine Facility configured for valve characterization testing