Numerical study on the auxiliary entrainment performance of an ejector with different area ratio

In this paper, an ejector-based multi-evaporator refrigeration system is proposed for the tropical region refrigerated trucks. CFD simulations are performed to study the auxiliary entrainment effect of the ejector operated in air-conditioning - freezing mode. First, the performance of the ejector with various auxiliary hole position in different chambers is investigated. Then, based on the optimal auxiliary hole position of each chamber, the influence of double and triple auxiliary holes on the ejector performance is identified. Next, optimal angle with the optimized auxiliary hole position is determined. Last, the effect of the ejector area ratio on optimal auxiliary hole position, angle and entrainment ratio is evaluated. The main results show that: (1) Optimal auxiliary hole position is 59.5 mm or the length ratio of distance between the inlet of constant-area mixing chamber and the auxiliary hole center point to the length of the constant-area mixing chamber is 1.90, and optimal auxiliary hole angle is 45 degrees; (2) The effect of the auxiliary hole position on the ejector performance is stronger than the auxiliary hole angle; (3) the optimum auxiliary hole position, angle as well as entrainment ratio are affected by the ejector area ratio.

Automated summary

The study shows that the impact of the auxiliary hole position on ejector performance is more significant than the auxiliary hole angle; the optimal auxiliary hole position is 59.5 mm, which has a crucial influence on ejector performance and entrainment ratio; the optimal auxiliary hole position, angle, and entrainment ratio are affected by the ejector area ratio.