Abstract Airfoil printed circuit heat exchanger (PCHE) is considered as one of the competitive candidates in the 3rd generation of concentrating solar power (CSP) plant, where the molten salt and supercritical carbon dioxide (S-CO2) are adopted as the heat transfer fluids (HTFs). To study the flow features and heat transfer performance of the two HTFs in the airfoil channel of PCHE, a three-dimensional numerical model was firstly developed and validated by experiment. Then, the friction features and heat transfer of the two HTFs under different mass flow rate and inlet temperature conditions were numerically investigated. Then, the performance of distributed airfoil channels was compared with that of straight channels and zigzag channels. Finally, the heat transfer and friction factor correlations were fitted for the two HTFs in the airfoil channel of PCHE, which can be used in relatively wide ranges of Reynolds number and temperature. The results show that the larger inlet temperature leads to higher heat transfer performance for molten salt, but causes lower heat transfer performance for S-CO2. The airfoil channels have the best comprehensive heat transfer performance among these three channels at the given pumping power. Moreover, the maximum deviations between the simulation results and the proposed heat transfer correlations are within ±6% for both the molten salt and S-CO2. Finally, the maximum deviations between the proposed friction correlations and the calculated results are within ±4% and ±8% for the salt and S-CO2, respectively. The correlations and results given in current study can contribute to the design and application of airfoil PCHEs in the 3rd generation of CSP plant.

中文翻译：

---

熔盐和超临界 CO2 在印制电路换热器翼型通道中流动的传热与摩擦

摘要 翼型印刷电路换热器（PCHE）被认为是第三代聚光太阳能（CSP）装置的竞争候选者之一，其中采用熔盐和超临界二氧化碳（S-CO2）作为传热流体。 (HTF)。为了研究PCHE翼型通道中两种HTF的流动特征和传热性能，首先建立了三维数值模型并通过实验验证。然后，数值研究了两种HTFs在不同质量流量和入口温度条件下的摩擦特性和传热特性。然后，将分布式翼型通道的性能与直通道和锯齿形通道的性能进行了比较。最后，对PCHE翼型通道中的两个HTF进行了传热和摩擦因数的相关性拟合，可以在相对较宽的雷诺数和温度范围内使用。结果表明，入口温度越高，熔盐的传热性能越高，而 S-CO2 的传热性能越低。在给定的泵功率下，翼型通道在这三个通道中具有最佳的综合传热性能。此外，对于熔盐和 S-CO2，模拟结果与建议的传热相关性之间的最大偏差均在 ±6% 以内。最后，对于盐和 S-CO2，建议的摩擦相关性与计算结果之间的最大偏差分别在 ±4% 和 ±8% 内。