The measurement of in-cylinder pressure during operation in reciprocating compressors is usually done in a destructive test in which a small bore is machined in the side of the cylinder. This instrumentation process not only impacts the real clearance volume of the compressor but also adds undesired dynamics to the measured value. This paper proposes a novel method for pressure measurement based on the connecting rod strain which solves most of the limitations of traditional methods. Experimental results obtained with a refrigeration compressor indicate that the proposed method presents errors smaller than ±0.2 bar for a coverage probability of 95% when compared with the values measured by a reference piezoelectric pressure transducer. The results are at least equivalent to the ones presented by traditional in-cylinder pressure measurement methods, but the proposed method uses a simpler setup and does not affect the compressor working condition.

中文翻译：

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使用连杆应变测量往复式压缩机的瞬时缸内压力

往复式压缩机运行期间的缸内压力测量通常是在破坏性试验中完成的，其中在气缸的侧面加工一个小孔。该仪表过程不仅会影响压缩机的实际间隙容积，而且还会为测量值增加不希望的动态。本文提出了一种基于连杆应变的压力测量新方法，解决了传统方法的大部分局限性。使用制冷压缩机获得的实验结果表明，与参考压电压力传感器测量的值相比，所提出的方法在覆盖概率为 95% 的情况下呈现出小于 ±0.2 bar 的误差。结果至少与传统的缸内压力测量方法所呈现的结果相当，