Progress of Cryogenics and Isotopes Separation

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The National Conference with international participation on New Cryogenic and Isotope Technologies for Energy and Environment - EnergEn 2018 is organized by the National Research-Development Institute for Cryogenic and Isotopic Technologies - ICSI Rm. Valcea with the scientific participation of the University of Pitesti and the University of Craiova and will be held at Baile Govora, in 2018.
MATHEMATICAL MODEL OF A HEAT EXCHANGER WORKING WITH DIFFERENT REFRIGERANT FLUIDS Print

 

MATHEMATICAL MODEL OF A HEAT EXCHANGER WORKING WITH DIFFERENT REFRIGERANT FLUIDS


Ion Zabet1*, Iulian Niţă1, Raluca Fako1, Graţiela Maria Ţârlea2


 


1Center of Technology and Engineering for Nuclear Project, 409, Atomistilor Street, Magurele, Ilfov, Romania

2Technical University of Civil Engineering Bucharest, 66 Blv. Pache Protopopescu, Bucharest, 021414, Romania





ABSTRACT


This paper involves building a model of a fin-and-tube heat exchanger geometry using EES software, creating a suitable geometry, setting up the cases (choosing solvers, numerical solution methods, etc.), making the calculations, and comparing results to known experimental data. The mathematical model can find a suitable heat exchanger to recover more Hydrogen with less quantity of Helium. Experiments done on fin-and-tube heat exchangers and reported in the literature are used for validation. The heat exchangers equipment used (for the validation of the model) were described in manufacturer product catalogue. The difference between calculated and manufacturer was ±4%. The model was validated in other applications. The model is working on the primary side with thermal fluids such as: R152a, R404A, R407C, R410A, R507A, R744, He and on the secondary side with gases such as: Air, H, T on the other side.
In the final of the paper it has been made a graphical comparison between refrigerants for heat exchanger geometry. In order to be able to liquefier more hydrogen and loss less (approx. 10 times less) is necessary to use a small quantity of Helium in a compact fin and tube heat exchanger. To analyze the capacity, mass flow, overall heat transfer coefficient, effectiveness and pressure drop of the heat exchanger, a model of fin and tube heat exchanger with the geometry describe in this paper was created using EES Software. In the simulations we used different input values for: secondary side fluid mass flow, evaporating and condensing temperature, inlet and outlet secondary side fluid temperature, atmospheric pressure and superheating difference temperature etc.
Keywords: cooling, heat exchanger, refrigerant, hydrogen, helium.
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*Corresponding authors: Ion Zabet, E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it