Thermodynamic optimization of the recuperative heat exchanger for Joule–Thomson cryocoolers using response surface methodology

• Response Surface Methodology was developed to analyze the heat exchanger.
• The available work loss minimization was introduced as a new criterion.
• The interacting effects of geometric parameters were considered in the study.
• The optimum geometric parameters of the heat exchanger were acquired and verified.

In this paper, a numerical study is performed to investigate the effects of geometrical parameters on the thermodynamic performance of the helically coiled recuperative heat exchanger in a Joule–Thomson (J–T) cryocooler. A novel optimization model is developed based on the available work loss minimization for the recuperative heat exchanger. The experiments are conducted based on four factors: L, Dt, S, Ds, one level: Nd, and the results are analyzed according to the principle of Response Surface Methodology (RSM). The final predicted optimum combination of geometrical parameters for the heat exchanger is: L = 430.5 mm, Dt = 0.45 mm, S = 5.41, Ds = 4.3 mm. The optimization results are in good agreement with our model, and the deviations of predicted values are less than 1.32%. The model and results presented here for the optimization of the heat exchanger can provide helpful guidance and a new way for the optimization of J–T cryocooler.