Exercise 4 Solution

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GROUP 13 De Donatis Lorenzo - 876178 Santoianni Genny, Nicole - 884523 Stucchi Simone - 874442 Politecnico di Milano Course: Building Energy Modelling 2016/17 Professor: Mario Motta Tutor: Rossano Scoccia BEM Assignment 04 - GROUP 13 Generation subsystem: condensing boiler Exercise description The aim of this exercise was to model the condensing boiler system and to create the final model. In order to model the condensing boiler, we took the results of the last assignment. Procedure I) In the first part of this exercise we designed the condensing boiler as follow: We took the maximum energy need and the maximum energy loss from the distribution subsystem to understand the energy that the boiler must provide to the system. 𝑄"#$,&''('(+𝑄*+,,,-.-'=17,68 𝑘𝑊ℎ Then we multiplied for the ƞ of the condensing boiler found using the graph that is related to the specific condensing boiler model: in our case is 0,89. 𝑄89,:#*:=𝑄89,.('#*∗ ƞ 89=19,87 𝑘𝑊ℎ At the end, we decided to use a condensing boiler with: 𝑄89,&+"=20 𝑘𝑊ℎ In trnsys we inserted this variable that represents the size of the boiler. To obtain the value requested in the point II we created two new printers: - One to print the value of Q_CB_out that represents the monthly average values of the heating that leaves the condensing boiler and enter in the distribution subsystem. - Another printer was created to print the monthly average values of the W_em,in , that represents the electric energy demand of the fancoils. To calculate these values, we created one new variable in the calculator parameter named ‘P_FC’ that represents the energy requested to the fancoil in order to heat the room. Then we created a new equation : 𝑃A8∗𝑛A8∗𝑔𝑎𝑚𝑚𝑎A8 This formula represents the quantity of energy demand. The last step was to connect…