Classification and main performance of HVAC chillers

Classification and main performance of HVAC chillers

Classification and main performance of HVAC chillers Commonly used chillers are divided into piston type, screw type, centrifugal type, and vortex type chiller according to the type of refrigeration compressor used. Their evaporators and condensers generally use shell and tube heat exchangers, the throttling device uses thermal expansion valves, the refrigerant is freon, piston, screw, centrifugal and vortex types use R22 or R134a, and the operation control adopts fully automatic Controlled and equipped with multi-level energy regulation. The cooling capacity range of water-cooled screw chillers is generally 125-1800kw, and most of the compressors use semi-hermetic screw type. Centrifugal chillers have a large single unit cooling capacity, generally greater than 1000kw, less floor space, low energy consumption, and high reliability. They are mainly used in office buildings, hotels, theaters, shopping malls, hospitals, etc. that require large and medium cooling capacity. Shell and tube condenser Under normal circumstances, most manufacturers will use high-efficiency condensing heat transfer tubes. The multiple spiral ribs and spiral protrusions on the outer surface of the tube greatly increase the heat transfer coefficient and heat transfer capacity. The optimized design of the internal structure effectively improves the anti-corrosion and anti-fouling capabilities of the condenser, and gives full play to the heat exchange effect of the condenser, thereby ensuring that the unit reaches a higher level of performance. The shell and tube condenser is also equipped with a safety valve, a vent valve, etc., to ensure the safety of the shell and tube condenser and the convenience of cleaning and maintenance. Shell and tube evaporator In general, most manufacturers use multi-spiral thin ribs and spiral protrusions on the inner surface of the tube to greatly improve the heat transfer coefficient and heat transfer capacity. It adopts a shell-and-tube structure, and the appearance adopts the latest flame-retardant, waterproof insulation material for heat preservation. The pressure resistance on the refrigerant side of the water cooler is 28Kg/cm2, and the pressure resistance on the water side is up to 20Kg/cm2. The PVC engineering plastic water baffle is installed inside the evaporator, which has strong anti-corrosion ability. The evaporator inlet is specially designed to make the refrigerant more evenly distributed in each copper tube to improve the overall heat transfer efficiency. Using the latest corrugated inner spiral high-efficiency heat exchange tube, the heat transfer coefficient is high. Evaporation in the tube has a high heat transfer efficiency to ensure the good cooling performance of the unit.