Experimental Investigation On Performance Of Plate Absorber

The LiBr-H₂O absorption chiller is driven by hot water, steam or burning gas; and the refrigerant is water. In the case of air pollution and energy scarcity, absorption chillers have been attached more attention for the two distinct characters: the use of environmentally friendly refrigerant and the heat driving. As a major component of an absorption chiller, the absorber has an important effect on the performance and size of absorption system. Direction from making a compact and efficient absorber, an experimental device was set up for testing the working performance of a vertical plate falling film absorber based on the single-effect lithium bromide absorption cooling system. The characters of the plate absorber are simple construction, vertically cuboid shape, easy arrangement, small floor area, facility of adjusting load and size. After designing, setting and debugging, the functions of setting experimental conditions, testing parameters, watching phenomenon in the plate absorber should been achieved. In addition, the performance of other types absorbers also could be tested in this system.Experimental study on performance of the plate absorber was carried out after the experimental system was finished. A single plate was adopt to study the effect of the parameters such as cooling water flow rate, inlet solution temperature, inlet solution flow rate on absorption heat and heat transfer coefficient of plate absorber. All tests were conducted with an aqueous LiBr solution with 62 wt% concentration, an inlet cooling water with 31℃ temperature, 11 ℃ evaporating temperature. And the inlet solution temperature range is from 35-75 ℃, the Reynolds number is from 50-200. The effect of additive (2-ethyl-l-hexanol) on absorption and heat transfer coefficient is tested with the varied solution concentration and flow rate.The results indicate that absorption heat increase with cooling water flow rate and decrease with solution temperature. The effect of additive on promoting absorption is obvious, absorption heat and heat transfer coefficient increased more than one time with additive than that without additive.