Exercise 1 Solution

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GROUP 13 De Donatis Lorenzo - 876178 Santoianni Genny, Nicole - 884523 Stucchi Simone - 874442 BEM Assignment 01 - GROUP 13 Exercise description The purpose of this exercise was the identification of the parameters (UA values) of our fan coil models in order to get the desired output values (in terms of outlet air Temperature and fan coil emission). Also, we evaluated the moist air outlet condition corresponding to those desired output values. Finally, the relationship between the UA values found and the corresponding inlet water mass has been plotted in a graph (for heach of the two fan coil models) for each assigned value of air mass. Trnsys procedure (described for the first analysis, then repeated similarly for each one) 1) The type mixer 5e has been selected 2) Some parameters have been changed: - specific heat of source side fluid 4.19 [kj/kg*K] (default, because its water) - specific heat of load side fluid 1.02 [kj/kg*K] (changed, because it’s air) 3) Inputs have been assigned - source side inlet T: 70°C – from table - source side air flow rate: 270 m3/h – from table - load side inlet temperature (= entering air T): 20°C – table - load side flow rate: from table 235 [m3/h] (BUT in trnsys it's given in a different unit!) – > transform unit of measurement manually or using transys with ‘equation’ tool (linking 2 calculators – create ‘Rho’ parameter(1.2 air density KG/m3), then create variable ‘m_FC_a’ (mass of air through the fan coil) given by ‘Rho*235 (m3/h)' and find [Kg/h] (unit of measurement required by the software). Create then a link to tell the software to take the value from the calculator. - UA: overall heat transfer of the exchanger [kW] à we have to find the correct value (changing it manually in an iterative process to find the searched outputs) 4)…