CO₂ is an excellent natural refrigerant that can be used in almost any commercial cooling application thanks to its useful range of evaporative temperatures and excellent environmental properties. However, due to its low critical temperature, CO₂ has an important issue related to the low performance of the simplest transcritical refrigeration cycle. To overcome it, the subcooling technique is a well-known method to improve the energy performance of any refrigeration cycle especially the CO₂ transcritical one. The IHX is a widely used example of this method that is implemented in almost all standalone systems that use CO₂ as a refrigerant. As an alternative of this element, in this work, a thermoelectric subcooling system is presented and tested in a CO₂ transcritical refrigerating plant. The experimental tests have been performed at two ambient temperatures: 25 and 30 °C, maintaining a constant evaporating level at -10 °C and varying the voltage supply to thermoelectric modules and the heat rejection pressure. The results from these experimental tests revealed that the COP and the cooling capacity of the refrigerating plant can be enhanced up to 9.9% and 16.0%, respectively, operating at the optimum operating conditions. Moreover, the experimental tests corroborate the existence of an optimum voltage which maximizes the COP, and the almost linear capacity regulation easily adjustable by varying the voltage supply.

由于其有用的蒸发温度范围和出色的环境性能，CO ₂是一种出色的天然制冷剂，几乎可用于任何商业制冷应用。然而，由于其低的临界温度，CO ₂具有与最简单的跨临界制冷循环的低性能有关的重要问题。为了克服这个问题，过冷技术是一种提高任何制冷循环（尤其是CO _2超临界循环）的能量性能的众所周知的方法。IHX是此方法的广泛使用的示例，几乎在所有使用CO _2的独立系统中都实现了IHX作为制冷剂。作为该元素的替代方案，在这项工作中，介绍了一种热电过冷系统，并在CO _2超临界制冷设备中进行了测试。已在两个环境温度（25和30°C）下进行了实验测试，在-10°C下保持恒定的蒸发水平，并改变了向热电模块提供的电压和排热压力。这些实验测试的结果表明，在最佳运行条件下运行，制冷设备的COP和制冷量可以分别提高到9.9％和16.0％。此外，实验测试证实了最佳电压的存在，该最佳电压使COP最大化，并且几乎线性的容量调节可通过改变电源来轻松调节。