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Screw compressor: In a screw compressor, the mutual engagement of the male and female rotors enables them to rotate within the casing, thereby carrying out the processes of suction, compression, and exhaust. Its main components include a screw compressor, condenser, evaporator, thermal expansion valve, and other control elements, which are fewer than those in a centrifugal compressor. It features a compact structure, reliable and balanced operation, few vulnerable components, high efficiency at partial load, and a long service life. Centrifugal chiller: It relies on the centrifugal force generated by the high-speed rotating impeller in a centrifugal compressor to provide power for cooling. Its main components include the centrifugal compressor, evaporator, condenser, throttling mechanism, vapor recovery device, lubrication system, and electrical control cabinet. It features high cooling capacity due to a single mechanism, but has drawbacks such as \"surge\". Screw compressors: The cooling capacity of a single screw compressor is lower than that of a centrifugal compressor, typically ranging from 30 RT to 500 RT. Therefore, screw compressors used for large-scale cooling applications now employ multiple compressors, which are controlled and regulated by a microcomputer; each compressor also has its own separate cooling system. Centrifugal compressor: A single centrifugal compressor can provide a large cooling capacity, ranging from 150 to 3000 RT; therefore, centrifugal chillers are usually designed with just one such compressor to meet the required cooling capacity. Screw compressor: The electric motor is directly connected to the main rotor and the auxiliary rotor, which mesh with each other to rotate at low speed. Centrifuge: An electric motor drives the impeller to rotate at high speed through a pair of speed-increasing gears. Screw compressor: A screw compressor uses hydraulic pressure to operate the slide valve in order to control capacity; under partial load, there is no uneven shock at all. For multi-head screw chiller units, the energy adjustment range is generally between 10% and 100%, allowing for continuous energy regulation. Especially in commercial and residential facilities such as hotels, shopping malls, and conference centers, the air conditioning load varies significantly with seasonal changes and fluctuations in foot traffic, which requires cooling units to have a wide range of energy adjustment capabilities. Centrifuge: Generally, the energy regulation range of centrifuge units is 40–100%. When operating at loads below 40%, these units are prone to experiencing \"surge\" phenomena; in severe cases, this can damage the core component of the unit – the impeller. Currently, many centrifugal compressor manufacturers use the method of \"air supplementation\" to bring the compressor’s surge threshold to 20% or 10%; however, this process requires a large amount of energy, resulting in relatively low efficiency of the compressor when its operation level is below 50%. Screw compressor: The screw compressor is a multi-compressor type with an independent cooling system; therefore, during maintenance or repairs, it is necessary to shut down the individual damaged compressor while the others continue to operate as usual. Centrifuge: Generally, centrifuges use a single compressor; when maintenance or repair is required, the entire machine must be shut down to stop its cooling operation. It has a complex structure, many vulnerable components, and high maintenance costs. Screw compressors: They achieve air intake and exhaust through the meshing rotation of male and female rotors. Their rotational speed is relatively low, usually at 2950 revolutions per minute, and their noise level is generally around 75 dB(A), while centrifugal compressors typically have a noise level of over 80 dB(A). Centrifuge: Generally, it operates at 9,000 to 40,000 revolutions per minute, and it uses blades or impellers to draw in and discharge air; as a result, its noise level is slightly higher than that of screw compressors, and the noise is more piercing. Centrifugal chillers and screw compressors consume a large amount of electricity, but under the same cooling capacity, the energy efficiency of screw compressors when operating at part load is higher than that of centrifugal chillers under similar conditions. With a total cooling capacity of 5632 Kw (1600 refrigeration tons), if 3 units are used, each unit will have a cooling capacity of approximately 650 refrigeration tons. Below, taking a 650-ton cold water chiller as an example, a comparative analysis of the power consumption of the two types of chillers is presented. Statistics show that when the chiller operates at full load, That is, 100% capacity, the time spent in this condition accounts for 2.3% of the total operating time, while 75%, 50%, and 25% correspond to other capacity levels. Their runtime accounts for 41.5%, 46.1%, and 10.1% of the total runtime, respectively. This project is calculated based on 4 months of air conditioning use per year: the total operating time is 4×30×10=1200 hours. Then for the unit, 100%, 75%, 50%, 25%. The running times were 27.6, 498, 553, and 121 hours respectively. Screw chiller units: Taking the manufacturer’s RSW-1000-4 unit as an example, its COP at full load is 5.24. The COP of the unit at 75%, 50%, and 25% load is 6.63, 7.23, and 6.03 respectively. The power consumption of the unit at 100%, 75%, 50%, and 25% load is respectively: 650×3.517×100%÷5.24=436Kw ； 650×3.517×75%÷6.63=259Kw ； 650×3.517×50%÷7.23=158Kw ； 95kW650×3.517×25%÷6.03=95Kw. The total electricity consumption over 4 months is: 436×27.6+259×498+158×553+95×121=239884 kWh. During 4 months of operation, the 650 cold ton unit consumed a total of 239,884.6 kWh of electricity for the screw compressor system ； The total electricity consumption of the centrifuge unit is 276,719 kWh. In other words, screw compressors save 36,834.4 kWh compared to centrifugal compressors, which means a reduction of nearly 15% in operating costs. Centrifugal unit: Taking the manufacturer’s 1000-19XR7070555EKS unit as an example, its COP at full load is 5.58. The COP of the unit at 75%, 50%, and 25% load is 5.97, 5.74, and 3.87 respectively. The power consumption of the unit at 100%, 75%, 50%, and 25% load is respectively: 650×3.517×100%÷5.58=410Kw ； 650×3.517×75%÷5.97=276Kw ； 650×3.517×50%÷5.74=199Kw ； 650×3.517×25%÷3.87=148Kw. Total electricity consumption over 4 months: 410×27.6+276×498+199×553+148×121=276719 kWh