摘要： The solar absorption-subcooled compression hybrid cooling system (SASCHCS) is tech-economically feasible for high-rise buildings. Since such a system operates with no auxiliary heat source, the performance coupling of its absorption subsystem and solar collectors is sensitive to the variation of hot water ?ow rate. In this regard, the relationship of system performance and hot water ?ow rate is required to be clari?ed exactly. Therefore, this paper aims to illustrate the e?ect mechanism of hot water ?ow rate and to propose the corresponding decision criterion. The case study is based on a typical high-rise o?ce building in subtropical Guangzhou. The daily working process of this system with di?erent hot water ?ow rates is simulated and analyzed. Subsequently, the useful heat of collectors and cooling capacity of the absorption subsystem with the hot water ?ow rate is discussed in detail. The results show that the SASCHCS operates with hot water temperatures ranging from 60 C to 90 C. The energy saving increases with the rise of hot water ?ow rate, but such variation tends to be ?at for the excessively high ?ow rate. As the collector ?ow rate increases from 1 m3/h to 10 m3/h, the daily energy saving improves by 21% in August. Similarly, the daily energy saving increases by 37.5% as generator hot water ?ow rate increases from 1 m3/h to 10 m3/h. In addition, the collector ?ow rate of 3.6 m3/h (13.33 (kg/m2 h)) and the generator ?ow rate of 5.2 m3/h (19.26 (kg/m2 h)) are optimal for the annual operation, with considering power consumption of water pumps. This paper is helpful for the improvement of SASCHCS operating performance.