Experimental study on operation characteristics of bubble pump with different working fluids

Solar powered air-conditioning systems with the absorption pair of lithium bromide and water are receiving much attention for the use of solar energy. To reduce absorption systems´ dependence on electricity totally, it is an important method to replace the conventional solution mechanical pump by the bubble pump. In order to further comprehend bubble pump, operation characteristics of bubble pumps with different working fluids of pure water and aqueous lithium bromide solution were investigated and compared. Experimental results show that startup time of bubble pump decreases with pump heat input and pumping frequency increases with heat input as pump lift and driving head are constant. As pump lift and heat input are constant, startup time of bubble pump increases with driving head and pumping frequency decreases with driving head. On the same conditions of pump lift, driving head and heat input, the pressure in separator and heating temperature of the bubble pump with aqueous lithium bromide solution are higher than that of bubble pump using pure water as its working fluids.