A 195 cm³ swash-plate piston expander was tested in an ORC using R245fa as working fluid. Rotational speeds ranging from 1,000 to 4,000 RPM and pressure ratios from 7 to 12 were imposed. In total, 65 steady state points were measured. With these measurements, performance maps were generated to point out the influence of rotational speed and levels of pressure on mechanical power and isentropic efficiency. These maps have highlighted the existence of an optimal rotational speed of around 3,000 RPM maximizing the mechanical power, while the speed that maximizes the isentropic efficiency lies between 2,000 and 2,500 RPM. The maximal mechanical power and isentropic efficiency were 2.8 kW and 53%, respectively. Then the measurements were used to analyze the losses. This analysis has shown that, under the expansion and compression limit, the theoretical isentropic efficiency has values comprised between 90 and 70% for pressure ratios of 7–12. The filling factor affects the isentropic efficiency for low rotational speeds and low pressure ratios. Indeed, indicated isentropic efficiency is around 60% for 1,000 RPM and around 75% for 4000 RPM. These values stay quite constant with the pressure ratio. Finally, a mechanical efficiency comprised between 40 and 90% was observed, which lowers the isentropic efficiency to values comprised between 30 and 53%. Finally, a model based on energy and mass conservation inside a cylinder volume was successfully calibrated and was able to predict mass flow rate, mechanical power, and exhaust temperature with good agreement. This model has enabled disaggregation of the influence of pressure drops and leakages on the filling factor, then on the isentropic efficiency. This analysis has shown that pressure drops mainly affect the compactness of the expander, and not so much the isentropic efficiency (except for low rotational speeds where pressure drops can lower the isentropic efficiency by 14%). In contrary, leakages have a strong impact. The importance of the different sources of losses varies with the speed. For the optimal speed of 2,500 RPM, under-expansion and compression have the strongest impact, followed by mechanical losses, leakages and pressure drops, respectively.

195厘米³斜盘式活塞膨胀器在ORC中使用R245fa作为工作流体进行了测试。施加从1,000到4,000 RPM的转速和从7到12的压力比。总共测量了65个稳态点。通过这些测量，生成了性能图以指出转速和压力水平对机械功率和等熵效率的影响。这些图突出显示了最佳旋转速度的存在，该旋转速度约为3,000 RPM，可最大化机械功率，而使等熵效率最大化的速度则介于2,000和2,500 RPM之间。最大机械功率和等熵效率分别为2.8 kW和53％。然后，将测量结果用于分析损耗。分析表明，在膨胀和压缩极限下，对于7–12的压力比，理论上的等熵效率值为90％至70％。对于低转速和低压力比，填充因子会影响等熵效率。实际上，对于1000 RPM，等熵效率约为60％，对于4000 RPM，其等效熵约为75％。这些值随压力比保持相当恒定。最后，观察到机械效率在40％至90％之间，这将等熵效率降低到30％至53％之间的值。最终，成功地校准了基于气缸容积内能量和质量守恒的模型，并且能够很好地预测质量流量，机械功率和排气温度。该模型可以分解压降和泄漏对填充系数的影响，然后关于等熵效率。该分析表明，压降主要影响膨胀机的紧凑性，而对等熵效率的影响不大（除了转速较低时，压降会使等熵效率降低14％）。相反，泄漏会产生很大的影响。不同损失来源的重要性随速度而变化。对于2,500 RPM的最佳速度，膨胀不足和压缩影响最大，其次是机械损耗，泄漏和压降。不同损失来源的重要性随速度而变化。对于2,500 RPM的最佳速度，膨胀不足和压缩影响最大，其次是机械损耗，泄漏和压降。不同损失来源的重要性随速度而变化。对于2,500 RPM的最佳速度，膨胀不足和压缩影响最大，其次是机械损耗，泄漏和压降。