Abstract For impinging jet ventilation (IJV) system, the energy efficiency is believed to be further improved by splitting the return vent from the exhaust device. However, how to properly set the return devices of IJV is unclear when it comes to a comprehensive consideration of the thermal comfort, indoor air quality (IAQ) and energy efficiency. In the present study, numerical simulations are performed to determine the thermal comfort indices (draught comfort (PD) and temperature gradient between the head and ankle levels (ΔT)), IAQ indices (air change efficiency (ACE) and contaminant removal efficiency (e)) and energy efficiency index (η) for an IJV system with return outlet height (H) ranged from the ceiling to the floor level. The technique for order preferences by similarity to an ideal solution (TOPSIS) method is employed to determine the optimal return vent height by considering these performance evaluation indices simultaneously. The results indicate that when the H increases, the values of ΔT and η decrease, while the values of PD, ACE and e increase. An optimal range of H (1.2–1.5 m above the floor) is recommended for the best overall performance of IJV. Moreover, a comprehensive graph of H is displayed in this paper, which could provide directions for optimizing the positions of exhaust and return devices.

中文翻译：

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基于TOPSIS法的排气/回风分流型冲击射流通风系统回风口高度优化研究

摘要 对于冲击射流通风（IJV）系统，认为通过将排气装置的回风口分流来进一步提高能效。然而，综合考虑热舒适性、室内空气质量（IAQ）和能源效率，如何正确设置IJV的回流装置尚不清楚。在本研究中，进行数值模拟以确定热舒适指数（通风舒适度 (PD) 和头部和脚踝之间的温度梯度 (ΔT)）、室内空气质量指数（换气效率 (ACE) 和污染物去除效率 (e) )) 和能效指数 (η) 的 IJV 系统，其回流出口高度 (H) 范围从天花板到地板水平。通过同时考虑这些性能评估指标，采用与理想解决方案相似的顺序偏好技术（TOPSIS）方法来确定最佳回风口高度。结果表明，当 H 增加时，ΔT 和 η 的值减小，而 PD、ACE 和 e 的值增加。为获得 IJV 的最佳整体性能，建议使用最佳 H 范围（距地面 1.2-1.5 m）。此外，本文还展示了H的综合图表，可为优化排气和回流装置的位置提供方向。为获得 IJV 的最佳整体性能，建议距离地面 5 m）。此外，本文还展示了H的综合图表，可为优化排气和回流装置的位置提供方向。为获得 IJV 的最佳整体性能，建议距离地面 5 m）。此外，本文还展示了H的综合图表，可为优化排气和回流装置的位置提供方向。