What is the Working Principle of an Evaporator?
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The principle of an evaporator involves heating a solution to vaporize and remove part of the solvent, thereby increasing the concentration of the solution—a process known as solution concentration. Below is an introduction to the working principle of an evaporator: 1. The equipment used for evaporation is called an evaporator. Since most solutions to be evaporated are aqueous, the evaporation process uses steam as the heating agent to generate vapor. The evaporator mainly consists of a heating chamber and an evaporation chamber. The heating chamber provides the heat required for evaporation, promoting the boiling and vaporization of the liquid. The steam generated in the heating chamber carries a large amount of liquid foam, which, upon entering the larger space of the evaporation chamber, is separated from the steam through self-condensation or the action of a demister. 2. The evaporator serves as a device for heating the refrigerant and absorbing heat from the surroundings. It primarily consists of a heating chamber and an evaporation chamber. The liquid refrigerant enters through the feed port, while heating steam heats the tube bundles inside the heating chamber. Due to the smaller heating surface area of the thicker central tube compared to the tube bundles, the vaporized refrigerant from the tube bundles rises into the evaporation chamber. 3. The liquid refrigerant in the central circulation tube descends to continue the cycle. (The cross-sectional area of the central circulation tube is approximately 40%–100% of the total cross-sectional area of the tube bundles, which directly affects the efficiency of the evaporator.) In fresh air heat exchange units and fan coil units, the evaporator primarily provides chilled water during the cooling process and heated refrigerant during the heating process. 4. In contrast to its role in ground source heat pump systems, during the heating process, the evaporator acts as a ground-side device, heating the circulating water on the ground side. The heated water is then transferred to the condenser through heat exchange in the unit, where the heat from the water is discharged by the condenser. 5. During the cooling process of the unit, the evaporator functions as an end device. The ground-side condenser condenses the ground-side water and supplies it to the evaporator to absorb heat from the surroundings, thereby achieving the cooling effect.
