基于吸收式制冷沿程加热气泡泵的启动性能

气泡泵是太阳能无泵吸收式制冷的核心部件,其启动性能影响无泵吸收式制冷机的实际工程运用。以水为工质,实验研究了系统初压力,沉浸高度,提升管入口工质温度,加热功率对沿程加热气泡泵启动性能的影响。实验结果表明:当加热功率过低时,气泡泵偶有泵起,但不能正常启动,存在一个最低启动功率。气泡泵正常启动分为三个阶段,延迟阶段:工质温度迅速攀升,但液体提升量为零。过渡阶段:工质温度缓慢上升,液体提升量不断升高。稳定阶段:温度和流量基本保持不变。系统初压力越低,启动时间和最低启动功率减小,提升管内工质温升速度越快。沉浸高度越高,系统越容易启动,但是对提升管出口工质温度的影响很小。系统初压力一定时,随着提升管进口工质温度升高,延迟时间和启动时间减小,当进口温度超过30℃时,其对延迟时间的影响已经很小。启动时间随加热功率的增加而减小。

Start-up Performance of Full-length Heating Bubble Pump based in Absorption Refrigeration Cycles

As the core component of absorption refrigeration unit,the start-up performance of the bubble pump affects the actual engineering application of absorption refrigerator unit.With water as the working fluid,the experiment emphatically studied the effect of initial system pressure,the immersion height,inlet temperature,and the heat input on the start-up performance of full-length heating bubble pump.The results showed that Startup process was divided into three phases,Delay phase:the working temperature rose rapidly,but the liquid mass flow rate is zero.The transition phase:the working temperature rose slowly,the liquid mass flow increased continuously,and the steady phase:the working temperature and the liquid mass flow rate remained stable;when the heat input was too low,the bubble pump occasionally pumped up,there was the minimum start-up power;the lower the initial system pressure,the lower the start-up time and the minimum start-up power,the faster the temperature rise of the working fluid;the higher the immersion height,the easier the system will start,the immersion height had little effect on the working temperature of the riser outlet;as the temperature of the riser inlet increased,the start-up time decreased.When the temperature exceeded 50℃,the influence of the riser inlet temperature on the start-up time was very small.The start-up time decreased as the heat input increased.