We present a novel measurement method for the characterization of thermal diodes in a saturated steam atmosphere. A measuring setup has been developed in which two pressure sensors are integrated. Using a developed analytical model, the heat flow, the volume flow, and the cracking pressure are determined from the measured absolute pressures and the pressure difference. The analytical model was verified using a flow through an orifice. We first calculated the volume flow through the orifice, with a diameter of 3 mm, using the Reader-Harris equation and then compared it to experimentally determined values. The experimentally determined values showed a discrepancy of 9%. With the measurement setup, we have characterized a check valve developed for magnetocaloric heat pumps, which has a thermally rectifying behavior. The developed check valve consists of three spring arms, which are radially attached to a valve disk. The heat flow through the check valve in the forward direction is 166 W for water, 239 W for ethanol, and 547 W for methanol at a temperature difference of 1 K. In the reverse direction, the heat flow is -0.03 W at a temperature difference of -1 K. For methanol, this corresponds to a rectification coefficient of more than 18 000.

中文翻译：

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在饱和蒸汽环境中表征热二极管的方法

我们提出了一种新的测量方法来表征饱和蒸汽环境中的热二极管。已经开发了一种测量装置，其中集成了两个压力传感器。使用开发的分析模型，热流、体积流量和开启压力由测得的绝对压力和压差确定。使用通过孔口的流动来验证分析模型。我们首先使用 Reader-Harris 方程计算通过直径为 3 毫米的孔口的体积流量，然后将其与实验确定的值进行比较。实验确定的值显示出 9% 的差异。通过测量设置，我们对专为磁热泵开发的止回阀进行了表征，该止回阀具有热整流行为。开发的止回阀由三个弹簧臂组成，这些弹簧臂径向连接到阀盘上。正向通过止回阀的热流为水 166 W，乙醇为 239 W，甲醇为 547 W，温差为 1 K。反方向，热流为 -0.03 W，温度为-1 K 的差异。对于甲醇，这对应于超过 18 000 的整流系数。