Modelagem e simulação dinâmica de ciclo de refrigeração operando com vazão variável de refrigerante

Abstract

This work presents the dynamic modeling and simulation, using the software Simulink/MATLAB, of a refrigeration vapor compression cycle main components: evaporator, compressor, condenser and expansion valve. The components are connected to simulate the cycle operation. Equipped with a control system, the cycle is coupled with an air-conditioned room model to attend the comfort settings. The heat exchangers are modeled using the moving boundary method, the compressor and valve use semiempirical models. The room is modeled to obtain temperature and humidity at each instant, based on transient thermal load data calculated using the RTS (Radiant Time Series) method. This tool allow to observe in real time any cycle operating parameter and evaluate its performance under different operating conditions regarding the main control variables, such as the compressor speed, valve opening and air flow. The main objective of the work is analyze the energy efficiency of a cycle operating with variable refrigerant flow (VRF) compared to an On/Off system and evaluate the cycle performance under various thermal load conditions.