关键词: 室内换热器, 流路优化, 分液不均, APF, 数值仿真

Abstract: To address the issues of uneven refrigerant distribution and limited heat exchange capacity in the indoor heat exchanger of a split-type air conditioner with bottom-inlet and top-discharge airflow, this study investigates various flow path layout strategies. Numerical simulations for three-path and four-path circuits were conducted using CoilDesigner software. The optimized flow path was then validated for energy efficiency against experimental data from an enthalpy difference test bench. The proposed novel "4-inlet and 4-outlet" flow path achieved a simulated cooling capacity of 98.17% of the rated nominal value (3520 W) under standard cooling conditions. The maximum superheat temperature difference across all branches was controlled within 5 °C, and the branch pressure drop was reduced compared to traditional schemes. Experimental validation demonstrated that the prototype with the new flow path reached a maximum tested APF of 5.48 under standard enthalpy difference test conditions, representing an improvement of 0.07 (≈1.3%) over the conventional four-path scheme. This confirms the effectiveness and feasibility of the simulation-based optimization. Finally, based on the research findings, practical flow path optimization strategies are proposed, providing a reference for the energy-efficient design of indoor heat exchangers in bottom-inlet top-discharge configurations.

Key words: Indoor heat exchanger, flow path optimization, uneven liquid distribution, APF, numerical simulation