Optimization of cooling load and coefficient of performance for real regenerated air refrigerator

Abstract

The performance analysis and optimization of a real regenerated air refrigerator is carried out by using finite-time thermodynamic method in this article. To maximize the cooling load and the coefficient of performance of the refrigerator, the heat conductance distribution between the hot-and cold-side exchangers and the regenerator for the fixed total heat exchanger inventory and heat capacitance rate matching between the working fluid and heat reservoirs are optimized, respectively. The influences of the pressure ratio, the total heat exchanger inventory, the efficiencies of the compressor and expander, the pressure recovery coefficient, and the ratio of the heat capacitance rates of heat reservoirs on the optimum characteristic of the refrigerator are shown by detailed numerical examples. The results obtained may provide guidance for the design of practice air refrigeration plants.

Influence of multi-irreversibilities on the performance of a Brayton refrigeration cycle working with an ideal Bose or Fermi gas

“…Using the Brayton refrigeration cycle model established here and the analysis method in Refs. [15,[23][24][25][26][27]36,37], one can further discuss the performance of an irreversible regenerative Brayton refrigeration cycle working with the quantum gases.…”

“…According to Fig. 1, one may introduce the compression and expansion efficiencies [16][17][18][19][20][21][22][23][24][25][26][27] …”

“…Consequently, the first approximation of the correction function can be expressed as [11,14] F (T , P ) = 1 ± EP /T 5/2 (24) where E = (2πh 2 /m) 3/2 /(4 √ 2k 5/2 ). By using Eq.…”

A generalized model of an irreversible thermal Brownian refrigerator and its performance

“…9. It can be seen that similar to the real conventional irreversible refrigerators [84][85][86][87][88][89][90][91][92][93][94][95][96], the curves of R ⁄ versus e are all closed loop- shaped ones. For each curve in the four figures, there exist a maximum cooling load (R Ã max ) with its corresponding COP (e R Ã ) as well as a maximum COP (e max ) with its corresponding optimum cooling load (R Ã e ).…”

“…In the figure, _ Q L is the heat leakage between the hot and cold reservoirs, _ Q 1 and _ Q 2 are, respectively, the rates of heat absorbed from the cold reservoir and released to the hot reservoir, and P is the power input into the system. This generalized irreversible thermal Brownian refrigerator model is similar to that for the macroscopic irreversible refrigerators [84][85][86][87][88][89][90][91][92][93][94][95][96].…”