Research on the thermal performance of SAC-HVIW system under the influence of solar transmission and local radiant heater

Abstract

Solar air collector (SAC ) combining with hollow ventilated interior wall (HVIW ) system is a new type of energy-saving and environmentally friendly heating system. In engineering applications, it will be affected by solar transmission and local radiant heat sources (external heat gain), but these factors have not been considered in previous studies. In this paper, the series connection of HVIW simplified heat exchange unit model is used to improve the original thermal network of the SAC-HVIW building, and experimental verification is carried out. Results show that the temperature deviation of the air cavity and the wall surface calculated by the model are all within 10%, which can be used for the external heat gain calculation of HVIW. Then, in order to research the influence of the intensity of external heat gain and the position of action on the thermal process of HVIW, seven cases of simulation calculation were designed. Results show that when the external heat gain is the same but the acting position is different, it has little effect on the minimum and fluctuation of the indoor air temperature (all within 0.1°C). However, the change of external heat gain has obvious influence on the minimum temperature. When the external heat gain of cases are 136W and 900W, the corresponding minimum temperature are about 0.5°C and 3.5°C higher than the cases of 82W, respectively.