Erfahrungs- und Forschungsbericht 2012 - Ensi

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Erfahrungs- und Forschungsbericht 2012 - Ensi

Figure 10: a) 3-D CAD of the cooling plate installed inside the 3.4 m high LINX vessel. The plate consists of a stack of 9 interchangeable

blocks that are independently temperature controlled. b) A supporting frame ensures the support and alignment

of the blocks with thermal expansion compensation. c) Picture of the Cooling/Heating block used for the temperature controlled

plate.

the heat flux through the plate. These blocks are

aligned and supported by a large metal frame. The

insulation in each side is made of Teflon plate and

PEEK material. The active height and width of the

plate are 250 cm and 40 cm respectively. The temperature

controlled blocks as well as the supporting

frame and insulation material were ordered and

received. A 3-D CAD view of the designed cooling

plate setup into the LINX vessel and details of a unit

block are presented in Figure 10.

As an important step the new design of the auxiliary

cooling/heating loop has been performed. This loop

will ensure the water supply (warm and/or cold) of

the 9 blocks by controlling the temperature and the

mass flow rate individual to each block. Deionized

water will be used to prevent heat transfer and surface

temperature homogeneity degradation due to

calcite formation. An open loop concept allows for

accurate feed water temperature control independent

of the experimental conditions. The water loop

design offers the possibility of having cold water injection

in the upper part of the plate while the lower

part is fed with warm water. Both condensation and

re-evaporation processes should be observable in

combination or individual. In order to decouple the

re-evaporation phenomena in a pure re-evaporation

case, the implementation of an artificial water film

injector is planned.

The difficulty of the design resides in the wide range

of thermal-hydraulics conditions that can be experimentally

investigated in the facility.

On the one hand a large mass flow rate is necessary

to avoid a too large temperature increase in

the blocks when condensation conditions are expected.

On the other hand, a small mass flow rate

is necessary to measure accurately any change in

temperature occurring under the re-evaporating

conditions. The dynamic range of the mass flow

rate easily reaches 1:50, a very high value which

reduces drastically the number of mass flow meters

and controllers that fulfill these specifications.

The solution of oval gear Kobold sensor was chosen

with possibility of changing the housing to increase

the dynamic range. The design was therefore done

in order to combine optimally the requirements on

the ranges of the measurable flow rates and temperature

increases expected in the blocks versus the

measurement accuracy. As of today, all the main

components of the auxiliary loop (i.e. flow meter,

valves) have been assessed, purchased and should

be received before the end of the year 2012.

Upgrading LINX facility and control system

During LINX reactivation, the main control board

appeared to have failed. Also, dating from mid 90’s,

parts of the control system implemented in LINX

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ENSI Erfahrungs- und Forschungsbericht 2012

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