An optimal design analysis method for heat recovery devices in building applications
An optimal design analysis method for heat recovery devices in building applications
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DOI：
10.1016/j.apenergy.2014.05.024
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发表时间：
2014-09
期刊：
影响因子：
11.2
通讯作者：
X. Liu;J. Niu
中科院分区：
文献类型：
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作者：
X. Liu;J. Niu
空气-空气热回收系统广泛应用于建筑应用中，以减少用于调节新鲜空气的能量。换热器芯体的几何形状是影响热回收系统整体性能的关键因素之一。为了更好地指导建筑应用中高性能换热器的开发，本文从实际应用的角度提出了一种新的分析方法。新的优化方法的目标是：在任何给定的质量流量，温度差和所需的热回收效率，以最小化的材料成本在指定的风扇能量使用，或者，以最小化的风扇能量使用在给定的材料成本。不同的管道几何形状与经典的j/affactor方法一起分析：等边三角形（Tri），圆形（Cyl），正方形（Squu），矩形与纵横比1/2（Rec（1/2）），1/4（Rec（1/4））和1/8（Rec（1/8））。一种新的通道结构命名为交叉波纹三角形（CCT）管道也被认为是比较。从节能角度看，在相同水力直径下，在层流区，Rec（1/8）型的泵送功率要求最低，而CCT型的泵送功率要求最高，说明采用该结构时能耗较大。相反，在指定的风扇功耗下，Rec（1/8）所需的总表面积最小，这意味着从节省材料的角度来看，平行板通道是最佳的几何形状。采用该方法，可以综合考虑制造成本和运行成本，实现最优设计。所提出的方法可用于选择目标导向的高性能热回收芯几何形状，以获得期望的热回收性能，从而减少空间、重量、支撑结构、能量需求和寿命成本。
Air-to-air heat recovery system is widely used in building applications to reduce the energy used for conditioning the fresh air. The heat exchanger core geometry is one of the key factors that affect the overall performance of a heat recovery system. To better guide the development of high performance heat exchangers in building applications, a new analysis method is proposed in this work from the practical application point of view. The objective of the new optimization method is: at any given mass flow rate, temperature difference and desired heat recovery effectiveness, to minimize the material cost at a specified fan energy use, or alternatively, to minimize the fan energy use at a given material cost. Different duct geometries are analyzed together with the classicalj/ffactor method: equilateral triangle (Tri), circular (Cyl), square (Squ), rectangle with aspect ratio 1/2 (Rec(1/2)), 1/4 (Rec(1/4)), and 1/8 (Rec(1/8)). A novel channel structure named cross-corrugated triangular (CCT) duct is also considered for comparison. From the energy saving point of view, under the same hydraulic diameter, the pumping power requirements for Rec(1/8) are the lowest when compared with the other shapes in the laminar flow region, while the pumping power requirements for CCT duct are the highest, indicating larger energy consumptions when using such structure. Conversely, with a specified fan power consumption, the required total surface area of Rec(1/8) are the smallest, which means that a parallel plate channel is the best geometry from the material saving point of view. By employing this method, the manufacturing and operating cost can be considered synthetically for achieving an optimal design. The proposed method can be used to select target-oriented high performance heat recovery core geometry for desired heat recovery performance, resulting in reduced space, weight, support structure, energy requirement and lifetime cost.