This paper reports on a micromachined Si/glass stack recuperative heat exchanger with in situ temperature sensors. Numerous high-conductivity silicon plates with integrated platinum resistance temperature detectors (Pt RTDs) are stacked, alternating with low-conductivity Pyrex spacers. The device has a 1 × 1-cm2 footprint and a length of up to 3.5 cm. It is intended for use in Joule-Thomson (J-T) coolers and can sustain pressure exceeding 1 MPa. Tests at cold-end inlet temperatures of 237 K-252 K show that the heat exchanger effectiveness is 0.9 with 0.039-g/s helium mass flow rate. The integrated Pt RTDs present a linear response of 0.26%-0.30%/K over an operational range of 205 K-296 K but remain usable at lower temperatures. In self-cooling tests with ethane as the working fluid, a J-T system with the heat exchanger drops 76.1 K below the inlet temperature, achieving 218.7 K for a pressure of 835.8 kPa. The system reaches 200 K in transient state; further cooling is limited by impurities that freeze within the flow stream. In J-T self-cooling tests with an external heat load, the system reaches 239 K while providing 1 W of cooling. In all cases, there is an additional parasitic heat load estimated at 300-500 mW.

中文翻译：

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用于高热负荷的 Si/Glass 本体微机械低温换热器：制造、测试和应用结果

本文报道了一种带有原位温度传感器的微加工硅/玻璃叠层换热式换热器。许多带有集成铂电阻温度检测器 (Pt RTD) 的高电导率硅板堆叠在一起，交替使用低电导率 Pyrex 垫片。该器件的占地面积为 1 × 1 cm2，长度可达 3.5 cm。它适用于焦耳-汤姆逊 (JT) 冷却器，可承受超过 1 MPa 的压力。在 237 K-252 K 的冷端入口温度下进行的测试表明，在 0.039-g/s 的氦质量流量下，热交换器的效率为 0.9。集成的 Pt RTD 在 205 K-296 K 的操作范围内呈现 0.26%-0.30%/K 的线性响应，但在较低温度下仍然可用。在以乙烷为工作流体的自冷测试中，带有热交换器的 JT 系统下降了 76。比入口温度低 1 K，在 835.8 kPa 的压力下达到 218.7 K。系统瞬态达到200 K；进一步冷却受到在流动流中冻结的杂质的限制。在具有外部热负载的 JT 自冷测试中，系统达到 239 K，同时提供 1 W 的冷却。在所有情况下，都存在估计为 300-500 mW 的额外寄生热负载。