Organic Rankine cycles are one of the available solutions for converting low grade heat source into electrical power. However the development of plants tends to be very expansive due to the specific design of the expander. Usually, the input parameters for designing an ORC plant are the temperature and power of the heat and cold sources. They lead to the selection of a working fluid, pressures and temperatures. The expander is then designed based on the required operating parameters. Using standard turbine easily available on the market and with well known performances would allow to reduce the development and manufacturing cost. However, the ORC would have to be adapted to make the expander work in its best conditions. For a solar concentrated heat source, the temperature and power can be adapted by adjusting the concentration factor and the total area of the collector. In this paper, a given gas turbine is considered to be used as the expander of the ORC. Knowing the turbine's performances with air, the optimal operating parameters (pressure, temperature, flow rate and rotational speed) of the ORC with different fluids are sought based on similitude rules. The adaptation aims to maintain the same density evolution, inlet speed triangle and inlet Mach number with the working fluid as with air. The performance maps of the turbine are then computed with CFD simulations and showed a maximum isentropic efficiency close to the one with air, about 78%.

中文翻译：

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标准径向涡轮机作为适应太阳能集中 ORC 的涡轮膨胀机的性能评估

有机朗肯循环是将低品位热源转换为电能的可用解决方案之一。然而，由于膨胀机的特定设计，工厂的发展往往非常广泛。通常，设计 ORC 设备的输入参数是热源和冷源的温度和功率。它们导致选择工作流体、压力和温度。然后根据所需的操作参数设计膨胀机。使用市场上容易获得且具有众所周知的性能的标准涡轮机将允许降低开发和制造成本。但是，必须对 ORC 进行调整，才能使膨胀机在最佳条件下工作。对于太阳能集中热源，温度和功率可以通过调整集中系数和集热器的总面积来调整。在本文中，考虑使用给定的燃气轮机作为 ORC 的膨胀机。了解涡轮在空气中的性能后，基于相似规则寻求 ORC 在不同流体下的最佳运行参数（压力、温度、流速和转速）。该适应旨在保持工作流体与空气相同的密度演变、入口速度三角形和入口马赫数。然后使用 CFD 模拟计算涡轮机的性能图，并显示出与空气接近的最大等熵效率，约为 78%。s 与空气的性能，ORC 与不同流体的最佳操作参数（压力、温度、流速和转速）是基于相似规则来寻求的。该适应旨在保持工作流体与空气相同的密度演变、入口速度三角形和入口马赫数。然后使用 CFD 模拟计算涡轮机的性能图，并显示出与空气接近的最大等熵效率，约为 78%。s 与空气的性能，ORC 与不同流体的最佳操作参数（压力、温度、流速和转速）是基于相似规则来寻求的。该适应旨在保持工作流体与空气相同的密度演变、入口速度三角形和入口马赫数。然后使用 CFD 模拟计算涡轮机的性能图，并显示出与空气接近的最大等熵效率，约为 78%。