Performance Analysis And Experiment Research On Internal Fin-plate Evaporative Condenser

Evaporative condenser was becoming the research hotspot because of the advantages of energy-saving, water saving and the compact structure. The optimization of internal structure in the internal fin-plate evaporative condenser and plate structure of heat transfer to strengthen the heat transfer performance of the internal fin-plate evaporative condenser was investigated. Also, the influence of spray density on the characteristics of gas-liquid two-phase flow of the internal fin-plate evaporative condenser was investigated. The main contents were as follows:(1)A new-type internal fin-plate evaporative condenser was proposed, and the optimization study was conducted for the performance of heat transfer. The influence of length of the baffle and fins on the performance of heat transfer was investigated. The results show that the turbulence intensity was increased and the outlet temperature was reduced with the increasing of the length of baffle. The outlet temperature was reduced with the increasing of the height and spacing of fins. When the length of baffle was 410 mm, the spacing of fin was 70 mm, and the height of fin 20 mm, the outlet temperature of the optimal model was reduced by 6.1% and the turbulence intensity is increased by 19.5% than that of the original model. The unit refrigerating capacity and coefficient of performance was respectively increased by 20.5% and 21.83% compared with the original model when the evaporate temperature was 268.15 K. At the same time, the heat transfer performance was enhanced.(2)Some kinds of new-type plate was comparably analyzed. The influence of the kind of plate, spray density and air velocity on the characteristics of gas-liquid two-phase flow and the performance of heat transfer were investigated. The results showed that the time of water film forming of the semicircle corrugated plate was lower and the heat transfer area was larger and the heat transfer performance of it was better. The optimal spray density of spray water for different kinks of evaporative condenser was different and the range of optimal spray density of spray water was in 0.48 kg/m·s-0.93 kg/m·s. The wall temperature of semi-circle corrugated plate was increased and the temperature of gas-liquid interface was decreased with the increasing of spray density if the air inlet velocity was constant. When the air inlet velocity is less than 2.5m/s, increasing air inlet velocity could reduce the thickness of water film of external semicircle corrugated plate effectively and the heat transfer would be enhanced.(3)The experimental platform of the internal fin-plate evaporative condenser was established to research the characteristic of water film flow. The water film flowing form with different spray density and the influence of spray density on the temperature field of heat-exchange plate were investigated. The results showed that the thickness of water film thinned with the decreased of the spray density; Affected by the plate type and gas fluid shear stress, water film flowing gathered toward the center area, and the phenomenon of water film splash appeared in local area with larger spray density; When the spray density were 0.524 kg/m·s, 0.738 kg/m·s, 0.905kg/m·s, the performance of heat transfer of semicircle corrugated plate is superior to the other plates. Also, heat-exchange area of plate was the main factor affecting the heat transfer performance with the range of spay density.