Measurement of Refrigerant Flow Rate

[newbieeng]

hi all,

I am thinking about measuring the refrigerant flow rate at the inlet of condenser and evaporator on a working household refrigeration. Could I do it easily? I have doubts about taking accurate measurements from refrigerant during working. Is it possible to measure the mass flow rate of a two-phase flow? For instance, if I assembled a "flow meter" at the inlet of the evaporator, could I take good results? And also I saw a few paper that mention "Coriolis flow meter". Is this Coriolis flow meter able to take measurements from a two-phase fluid flow? I really do not know anything about this subject and trying to learn how to cope with it, so I need help on this.

Thanks in advance.

[taz24]

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You don't have to actualy measure it, it can be calculated on paper.

Use cool pack

http://www.ipu.dk/English/IPU-Manufacturing/Refrigeration-and-energy-technology/Downloads/CoolPack.aspx

And put all the readings into the software and it will callculate mass flow for you.

Mass flow will be the same going into the cond and the evap by the way :)
The refrigerant will flow through the system at the same rate even in mixed phases.

All the best

taz

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[taz24]

This is a screen shot of a system based on R134a with 0.4 Kw duty, small superheat and subcooling.
It shows about 0.00247268 Kg/s Mass flow.

taz
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8660

[newbieeng]

thank you taz,
maybe I explained myself wrong way. all I want is to determine that whether the mass flow rates at evap and cond are the same or not via experimentally. Thanks again your suggestion. do you know how does the coolpack find mass flow rate of the system? which equations does it use?

[taz24]

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Try this site..

http://www.freestudy.co.uk/thermodynamics/t5201.pdf

http://www.ideals.illinois.edu/bitstream/handle/2142/9750/TR048.pdf


On page 52 of the second pdf there is a good definition of Mass flow.

All the best

taz

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[newbieeng]

thx max.
I will read these.