Performance Analysis Of Optimization Of Quantum Harmonic Otto Refrigerator

Abstract

Quantum Otto refrigerator in adiabatic driving, for both high-temperature regime and low temperature regime, can be mapped to Feynman's ratchet and pawl model. Finite time cycle period for a quantum Otto machine implies that either an adiabatic stroke or an isochoric process precedes in finite time duration. The quantum Otto refrigerators under consideration consist of two adiabatic strokes where the system (isolated from the heat reservoir) undergoes finite time unitary transformation and two isochoric steps where the system may not reach thermal equilibrium even at the respective ends of the two stages due to finite time interaction intervals. The harmonic Otto refrigeration cycles of a modeled harmonic oscillator operating under the conditions of maximum Ω-function was investigated. This trade-off objective function represents a compromise between energy benefits and losses for a specific job, in adiabatic frequency modulations. The study examines analytical expressions for the optimal performance both in the high-temperature (classical) regime and in the low-temperature (quantum) limit. The analytical expressions for coefficient of performance of the Otto cycle were derived. The variation of quasistatic process and process at maximum power disturbs the usage of a refrigerator. This means that in quasistatic process coefficient of performance is greater whereas power become vanishes. As well as at maximum power, coefficient of performance minimized. Due to this gap it should be optimized to analyze the performance of quantum Otto refrigerator. So, the study introduces the optimized quantity for the two temperatures. In addition, it tries to scale optimum value and maximum value. Finally, the coefficient of performance and power explained by figure of merit for adiabatic driving.