Estudo experimental e modelo de simulação para determinação da massa de uma bomba de calor assistida por energia solar de expansão direta carregada com CO2 e o efeito da irradiação sobre o COP e o TEWI do sistema

Abstract

The present work is a study on the effect of solar irradiation on the mass inventory, coefficient of performance (COP) and total equivalent impact on global warming (TEWI), in a heat pump (BDC) of direct expansion assisted by solar energy (DX-SAHP). The equipment operates in the transcritical cycle, with CO2 as the refrigerant. The knowledge of its mass under different insolation conditions is essential for BCD to achieve high-energy efficiency. Thus, 48 experimental operation points were evaluated, and a mathematical model was developed to estimate the amount of mass in each part of the BDC. The phenomena of heat transfer, head loss, biphasic fluid in the evaporator and supercritical fluid in the gas cooler were considered. The model obtained an average error of 6.32% in the mass calculation, with the results concentrated within a tolerance range of ± 18%. In general, it was found that the increase in irradiation maximizes the value of the COP, minimizing the TEWI, and among the conditions analyzed, the best point of operation occurred with a COP of 6.5. For this situation, the TEWI was 1047 kg CO2-eq and the mass 609g, with an error of 5.6%.