Abstract The use of Milli-Channel Heat Exchangers (MCHE) presents numerous assets: efficient heat transfer, huge compactness, and limited pressure drop. For an engineer, the Fanning friction factor and the convective heat transfer coefficient are two main parameters to describe the performance of a heat exchanger. A brazed MCHE with rectangular channels in stainless steel made by the Institut für Mikrotechnik Mainz (IMM, Mainz, Germany) has been characterized experimentally and theoretically in a counter-current configuration. The selected working fluids are deionized water and oil without any phase change during experiments. The pilot unit ensures measurements of pressure drops, temperatures, and volumetric flow rate of each fluid flowing in laminar regime. A one-dimensional model has been developed. The temperature and pressure profiles of each fluid are represented by differential equations associated with boundary conditions. The system of coupled equations consists in a two-point boundary value problem solved numerically by the Matlab software. The parameters of a Nusselt number correlation are identified together with those of a Fanning friction factor one by minimizing a sum of squared differences between experimental and predicted data. The calculated temperature and pressure profiles present a good agreement with measurements. A statistical analysis shows that each optimized parameter is significant.

中文翻译：

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用于液-液传热的紧凑型微通道换热器的实验表征

摘要 微通道换热器 (MCHE) 的使用呈现出众多优点：有效的传热、巨大的紧凑性和有限的压降。对于工程师来说，范宁摩擦系数和对流传热系数是描述换热器性能的两个主要参数。由 Institut für Mikrotechnik Mainz（IMM，Mainz，德国）制造的不锈钢矩形通道钎焊 MCHE 已在逆流配置中进行了实验和理论上的表征。所选工作流体为去离子水和油，在实验过程中没有任何相变。先导单元确保测量层流状态下每种流体的压降、温度和体积流量。已经开发了一个一维模型。每种流体的温度和压力分布由与边界条件相关的微分方程表示。耦合方程组包含一个由 Matlab 软件数值求解的两点边值问题。通过最小化实验数据和预测数据之间的平方差的总和，将努塞尔数相关性的参数与范宁摩擦系数 1 的参数一起识别。计算出的温度和压力曲线与测量值非常吻合。统计分析表明，每个优化参数都是显着的。通过最小化实验数据和预测数据之间的平方差的总和，将努塞尔数相关性的参数与范宁摩擦系数 1 的参数一起识别。计算出的温度和压力曲线与测量值非常吻合。统计分析表明，每个优化参数都是显着的。通过最小化实验数据和预测数据之间的平方差的总和，将努塞尔数相关性的参数与范宁摩擦系数 1 的参数一起识别。计算出的温度和压力曲线与测量值非常吻合。统计分析表明，每个优化参数都是显着的。