Abstract: In response to the issue that building grilles affect the high-temperature refrigeration performance of air conditioners, this paper first uses CFD numerical simulation method to calculate the air flow loss caused by grilles, and analyzes the flow field distribution of outdoor units of air conditioners inside and outside the grilles. In addition, experiments and numerical simulations were conducted to investigate the improvement of high-temperature refrigeration performance by installing the outdoor unit, adjusting the outlet angle, and adding a guide coil. Research has shown that after installing building grilles, the air outlet grille pass rate of outdoor units is 16.68%. To increase the air output, try to place the outdoor unit tightly against the grille during installation, reduce the distance on the front side, and increase the distance on the left side if the distance and installation permit. It is recommended that this position be greater than 170 mm. Concentrated air output can improve the grid air output rate, reduce the air output angle from 45 ° to 0 °, and increase the grid air output by 76.20%. The installation of air guide rings on the grille has improved the performance of the air conditioner inside the grille. The grille pass rate can reach about 50%, the cooling energy efficiency can be improved by 4.53%, the cooling capacity can be increased by 73.08%, and the cooling capacity can reach 90.82% without the grille.

Key words: Air conditioner outdoor unit, High temperature refrigeration, Architectural grating, Return airflow, Air volume increase