A continuing research on the direct expansion solar assisted ejector-compression heat pump cycle for water heater is presented in this paper, aiming to reveal the system dynamic characteristic by experimental method. The performance advantage of the presented system is verified at first. According to the test results, under the considered condition, the presented system can outperform the traditional ejector enhanced heat pump system and the air-source heat pump system by 24.1% and 29% in the heating coefficient of performance aspect, 24.2% and 30.5% in the average heating capacity aspect. After that, the main parameters affecting the dynamic behavior of the presented system are examined, including the ejector nozzle exit position, ejector mixing chamber diameter and solar radiation intensity. According to the test results, the system achieves the maximum heating coefficient of performance and heating capacity under mixing chamber diameter of 4 mm and nozzle exit position of 6 mm. Note that the ejector malfunction phenomenon appears when the mixing chamber diameter is reduced to 3 mm, due to the blocked flow channel of the ejector secondary flow. Additionally, the experiment finds that enhancing the solar radiation can obviously improve the ejector pressure lift ratio and help the system achieve superior heating performance.

本文对热水器直接膨胀式太阳能辅助喷射器-压缩热泵循环进行了持续研究，旨在通过实验方法揭示系统的动态特性。首先验证了所提出系统的性能优势。根据测试结果，在所考虑的条件下，所提出的系统在性能方面的供热系数方面分别优于传统喷射器增强型热泵系统和空气源热泵系统24.1%和29%、24.2%和30.5%在平均制热能力方面。之后，检查了影响所提出系统动态行为的主要参数，包括喷射器喷嘴出口位置、喷射器混合室直径和太阳辐射强度。根据测试结果，该系统在混合室直径为4mm，喷嘴出口位置为6mm的情况下，实现了最大的加热性能系数和加热能力。注意，当混合室直径减小到3mm时，喷射器故障现象出现，这是由于喷射器二次流的流道堵塞。此外，实验发现，增强太阳辐射可以明显提高喷射器压力提升比，帮助系统实现优越的加热性能。