The transcritical carbon dioxide heat pump cycle has been drawing much research interest due to its environmental friendliness and the thermodynamic features of carbon dioxide. However, there is one concerning issue, which is the huge exergy loss associated with the isenthalpic process in the expansion valve. In the current study, a new transcritical carbon dioxide heat pump cycle is proposed, where a Tesla turbine replaces the expansion valve. The Tesla turbine is a bladeless turbine that works with any two-phase fluid, which is the case for the expansion of supercritical CO₂. A 3D computational fluid dynamics model is first developed to simulate the flow of carbon dioxide within a Tesla turbine, and then the extracted results are used as data for subsequent thermodynamic modeling of the heat pump cycle. The Tesla turbine power production and exergy losses, as well as the proposed heat pump cycle coefficient of performance are investigated in terms of the turbine rotor angular velocity and the gas cooler and evaporator pressures. It is demonstrated that the coefficient of performance of the cycle where a Tesla Turbine is integrated is up to 16.3% higher than the traditional cycle with the expansion valve. In addition, at rotor angular velocity equals to 1000 rad/s, the turbine power is maximum and increasing the inlet pressure leads to the higher torque and consequently higher turbine power. At lower inlet pressure, the coefficient of performance of the heat pump cycle is higher. A thermodynamic trade-off is illustrated between the power production from the Tesla turbine and the vapor quality at the outlet of the Tesla turbine, as a function of rotor angular velocity. It is numerically proven that the optimum rotor angular velocity corresponds to the maximum exergy efficiency of the Tesla turbine, which in turn leads to the maximum coefficient of the performance of the whole cycle.

跨临界二氧化碳热泵循环由于其环境友好性和二氧化碳的热力学特性而引起了很多研究兴趣。然而，存在一个令人担忧的问题，那就是与膨胀阀中的等焓过程相关的巨大的火用损失。在当前的研究中，提出了一个新的跨临界二氧化碳热泵循环，其中特斯拉涡轮机取代了膨胀阀。Tesla涡轮机是无叶片涡轮机，可与任何两相流体一起工作，超临界CO ₂的膨胀就是这种情况。首先开发3D计算流体动力学模型以模拟Tesla涡轮机内二氧化碳的流动，然后将提取的结果用作数据，用于热泵循环的后续热力学建模。根据涡轮转子角速度以及气体冷却器和蒸发器压力，研究了特斯拉涡轮的发电量和火用损失，以及建议的热泵循环性能系数。事实证明，集成了Tesla Turbine的循环的性能系数比带有膨胀阀的传统循环高出16.3％。另外，在转子角速度等于1000 rad / s时，涡轮机功率最大，并且增加入口压力会导致更高的扭矩，从而导致更高的涡轮机功率。在较低的进口压力下 热泵循环的性能系数较高。示出了在特斯拉涡轮的功率产生与特斯拉涡轮的出口处的蒸气质量之间的热力学折衷，该折衷是转子角速度的函数。数值证明，最佳转子角速度对应于特斯拉涡轮的最大火用效率，进而导致整个循环的最大性能系数。