Parametric Study of a Finite-Time Steady Flow Reversed Lenoir Refrigeration Cycle

Ideal reversed heat engine cycles have long been the benchmark for refrigeration systems globally. By applying the concept of finite-time thermodynamics to ideal power and refrigeration cycles, researchers have modeled irreversible cycles that closely emulate real-world operations. In this study, a parametric analysis of the finite-time reversed Lenoir cycle was conducted, representing the first exploration of this reversed cycle using this approach. Key output parameters, such as the coefficient of performance (COP) and power input to the refrigeration cycle, were investigated. The analysis covered critical performance factors, including heat exchanger design, fluid properties, ambient conditions, and state values of the reversed Lenoir cycle, all of which impact the power input Ẇ and the COP of the finite time reversed Lenoir cycle, COP_LR. Additionally, an irreversible compression efficiency was incorporated to account for the various internal and external irreversibilities encountered during the cycle. The study examined the balance between a stable COP_LR across different values of the higher heat exchanger effectiveness, ϵ_H (hot side) and ϵ_L (cold side), and the marginal enhancement in COP_LR at elevated pressure ratios π, ranging from 4 to 7. Furthermore, the cycle operation was compared with the well-established reversed Brayton cycle to evaluate performance parameters.