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COBEM 2017
24th ABCM International Congress of Mechanical Engineering
DISTRIBUTED MODEL TO ACHIEVE THE STEADY STATE THROUGH THE FALSE TRANSIENT IN A SOLAR ASSISTED HEAT PUMP
Submission Author:
Tiago de Freitas Paulino , MG
Co-Authors:
Tiago de Freitas Paulino, Raphael Nunes Nunes de Oliveira, Luiz Machado, Ricardo Koury
Presenter: Tiago de Freitas Paulino
doi://10.26678/ABCM.COBEM2017.COB17-0403
Abstract
In this study, the distributed model of a direct expansion solar assisted CO2 heat pump are used. The methodology shows that it is possible for the system to achieve the correct steady state without it passing through a real transient, with the false transient operating during the initial part of the process. It is shown that, regardless of the initial temperature and mass distribution in the evaporator, if all points are in the same isochoric, then the same steady state will be achieved through the false transient. The isochoric of 0.00384 m³/kg was chosen and two points on this curve are used. The total mass are 120 grams in both points. The results show that the same evaporating temperature around 14.5°C and the superheat of 6 °C, was achieved in the steady state. Moreover, the liquid mass is 52 grams and the vapor mass is 68 grams in the steady state. The results of the simulation of the false transient were compared with the results achieve through the real transient simulation demonstrate a good agreement. Therefore, this methodology is appropriate to achieve the steady state in a simpler manner.
Keywords
mathematic model, false transient, steady state, CO2 heat pump, solar assisted
