基于制冷剂R141B的喷射器混合模型及其实验验证

Experimental validation of a hybrid ejector model with refrigerant R141B

建立了一个简单且有效的喷射器混合模型。首先利用热力学、流体力学原理导出一个计算喷射器引射系数的基本方程;然后用一个二维函数来近似引射流的速度分布,对导出的基本方程进行简化;最后通过数值研究和集总参数法得到了一个喷射器混合模型。与现有的模型进行比较,新模型非常简单,只有一个方程且只含3个常系数,因此该模型可以用于喷射器的实时控制与优化。文中还介绍了辨识这3个常系数的方法。最后建立了一个基于制冷剂R141B的喷射制冷系统,实验验证结果表明新模型能精确地预测喷射器的性能。

A simple but effective hybrid ejector model was developed. First a fundamental model for calculating entrainment ratio was derived based on thermodynamic and fluid dynamic principles. Then a 2D velocity function was used to approximate the velocity distribution of entrained flow to simplify the fundamental equation. Based on numerical studies and the lumped-parameter method, the hybrid ejector model was finally established. Compared with the existing models, the developed model was very simple, consisting of only one equation and three constant parameters. Therefore the model can be used in real time control and optimization of ejector systems. Furthermore, the procedure for identifying the parameters was presented. In the end, an ejector refrigeration system with refrigerant R141B was investigated. The results of the experimental validation showed that the proposed model could accurately predict the ejector performance.