"Cooling Fan" cooling liquid (water or brine) evaporator, the evaporator can be divided into horizontal shell and tube evaporator (refrigerant tube evaporator flooded, the refrigerant in the evaporator tube called dry), and risers cold water tank. Evaporator cooling air, the evaporator can be divided into two categories, one is made of natural convection air evaporation pipes, such as widely used in cold storage wall pipes, the top row of pipes, generally made the establishment of a tube, single-row coil, double coil, double U-shaped pipe or four rows of U-tube type and other types; the other is the forced air flow chillers, cold storage chiller system used to make the box type, air conditioning clusters are usually used in pipe system made of ribbed sheet, in which the cooler, the refrigerant by pressure, gravity or the liquid head pressure pump generates a flow in the tube, because the cooling medium is air, air side heat transfer coefficient is very low, so the heat transfer coefficient of the evaporator is low. In order to improve heat transfer performance, often take to increase heat transfer temperature difference, heat transfer tube plus fin or increase air flow and other measures to achieve their goals.