The supply momentum-driven stratified thermal environment created by advanced air distribution is a promising solution for sustainable and livable indoor environments. This study proposes a strategy to decouple the exhaust and return air for the supply momentum-driven stratified thermal environment. Experimentally validated Computational Fluid Dynamics simulations are used to verify the effectiveness of the strategy regarding energy efficiency improvement in a stratum-ventilated office. The proposed decoupled strategy positions the return vent below the exhaust vent and above the supply vent. The proposed decoupled strategy has two mechanisms for energy efficiency improvement, i.e., 1) reducing the cooling load of return air by lowering return air temperature relative to exhaust air temperature, and 2) advancing the airflow pattern with improved cooling efficiency of the occupied zone by reinforcing and suppressing the entrainments of the supply air jet from the occupied zone and the upper zone, respectively. The advanced airflow pattern reduces the cooling loads of both return air and fresh outdoor air and increases the Coefficient of Performance. Decreasing the height of the return vent strengthens Mechanism 1, but nonmonotonically affects Mechanism 2. By properly determining the height of the return vent, results show that the proposed decoupled strategy saves energy by 13.5% and 11.9% in thermally neutral and slightly warm environments, respectively. This study contributes to advancing air distribution for energy saving with thermal comfort.

中文翻译：

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供气动量驱动的分层热环境的排气口和回风口解耦，并加强了来自占用区的供气射流夹带


由先进空气分配创造的供应动量驱动的分层热环境是可持续和宜居室内环境的一个有前途的解决方案。本研究提出了一种在供气动量驱动的分层热环境中解耦排气和返回空气的策略。经过实验验证的计算流体动力学模拟用于验证该策略在分层通风办公室中提高能源效率的有效性。建议的解耦策略将回风口定位在排气口下方和送风口上方。所提出的解耦策略具有两种提高能源效率的机制，即 1） 通过降低相对于排气温度的回风温度来减少回风的冷却负荷，以及 2） 通过加强和抑制来自占用区和上部区域的送风射流的夹带，提高占用区的气流模式并提高冷却效率， 分别。先进的气流模式降低了回风和新鲜室外空气的冷却负荷，并提高了性能系数。减小回风口的高度会加强机制 1，但非单调性地影响机制 2。通过正确确定回风口的高度，结果表明，所提出的解耦策略在热中性和微热环境中分别节省了 13.5% 和 11.9% 的能源。本研究有助于推进空气分布，通过热舒适实现节能。