Modular Air-cooled Screw Chiller

Description
This modular air-cooled screw chiller is a High-efficiency screw chiller that can be connected to all sorts of fan coil units to realize cooling/heating effects for civil or industrial buildings.

air-cooled-screw-chiller

Features:
●V type fin structure brings this unit small refrigerant pressure loss and high efficiency. 
● With a flooded-type shell-and-tube design, the evaporating temperature is increased, and the heat exchanging efficiency improves. 
● Less noise fan blades and the special compressor noise reduction device make noise below 5dB(A). 
● Totally-enclosed design, good-looking body. 

air-cooled-chiller-compressor
air-cooled-chiller-evaporator

● Special flooded screw compressor. 
A. Special motor with Grade F and thermos ability of 155°C. 
B. No speed-up gear mechanism design: twin screw compressor adopts direct-connected driving motor for reducing driving efficiency loss and for a more compact structure; 
C. Motor of the compressor is cooled down through diluent cooling of gas-absorbing cavity to lower the temperature of motor, and ensure diluent cooling of refrigeration oil. Through which can prevent decrease of insulativity due to high temperature of motor, otherwise the motor will be burnt. 
D. Built-in air exhaust check valve: it can prevent back flow of refrigerant when the unit closes down; built-in oil separator and oil heater for ensuring oil return. 
E.    Slide valve stepless adjustment for exact match of cooling output and load of compressor. 
F. High accuracy SKF shaft bearing: This twin screw compressor adopts high accuracy SKF shaft bearing so that the clearance of compressor can be smaller, transmission efficiency will be higher, energy efficiency ratio of compressor will be higher, and service life of compressor will be longer.

● Reliable compressor operating range control technology (initially created in the industry) 
The built-in pressure transducer and current transformer can conduct comprehensive control of high pressure, low pressure, current of compressor, and air exhaust temperature, so as to ensure reliable operation of compressor within the operating range.

● Compressor motor cool-down technology (initially created in the industry) 
It adopts electronic expanding valve control with wide adjustment range, which can precisely control gas absorbing and liquid spray volume; apply PD control method to feedback liquid spray information in advance can achieve fast adjustment and cool down motor directly, through which can control tempera-ture of motor and ensure reliability and performance of compressor.

 

air-cooled-screw-chiller-specification
air-cooled-screw-chiller-specification
air-cooled-screw-chiller-specification
air-cooled-screw-chiller-specification

Self-developed High-efficiency Vertical Oil Separator
This chiller adopts an external oil separator design, apply four stage (rotate separation, collision, and natural 
Sedimentation, filter separation) separating technology to ensure adequate filtration of refrigeration oil discharged from compressor, and prevent the refrigeration oil from leaking into the system. The real measurement efficiency of oil separation is up to 99.97%.

chiller-Vertical-Oil-Separator
chiller-valve-control

High-efficiency and Energy-saving
● Flooded shell and tube design: this chiller adopt TURBO-BII ultra high efficiency evaporator that the evaporating pipe is soaking in liquid refrigerant for improving heat transfer capacity and cooling efficiency, the evaporating temperature is higher than 5.5℃; chilled water pass through the tube for re-duking flowage pressure loss of water side and reduce energy consumption of water pump. This evaporator works with the high-performance and reliable special screw compressor, which can greatly improve cooling capacity and energy efficiency ratio of the unit. 

● Independent design of multiple compressors and multiple systems: It has 4 independent systems at most, with high energy efficiency of partial loading; the compressor adopts Y-Δ start-up with low start-up current.


● V-shape condenser design: It adopts V-shape layout with the best angle and the best air volume for more even distribution of air flow; it adopts ripple fenestration aluminous condensing fin for higher heat exchange efficiency. 
 
● Circulating design of economizer *(optional): auxiliary refrigerant of economizer conducts heat exchange with main refrigerant, to improve condenser depression of refrigerant when the main refrigerant returns to the expanding valve inlet, and improve liquid seal effect, ensure refrigerant entering into main throttle valve (electronic expanding valve) is in liquid state; at the same time the auxiliary refrigerant directly gets into compressor after it is gasified, which will increase inspiratory capacity of compressor. Such design can help to increase cooling capacity for 10%.

 

● High-accuracy electronic expanding valve control: stepping motor can have 3810 steps at most, which combines coarse tuning and sharp tuning for precisely adjusting flow of refrigerant. It can dynamically control degree of superheat for outlet of evaporator, to achieve higher utilization ratio of heat exchange area and improve operational efficiency under deviate work condition and low-load work condition.

chiller-Circulating-design-economizer
chiller-control

● Advanced Self Adapting Control: 
A. Automatically adjust yielding water temperature according to variation of load to ensure comfortable experience and energy saving during transition seasons; 
B. Start-up quantity of fan units can be controlled according to pressure, which can achieve more energy-saving in transition seasons. 
● Heat recovery function *(optional): It uses heat reclaim shell and tube to reclaim waste heat, the heat reclaim volume can be up to 20%; the water heated up by reclaimed heat can be up to 55℃; heat reclaim and non-heat reclaim work condition can be freely switched during operation, which can prevent energy waste in closing down the unit and conduct switch; quantity of fan units can be controlled according to high pressure, heat reclaim water temperature, ambient temperature, which can ensure the highest heat reclaim efficiency, and at the same time conduct air conditioning and supply hot water. It is the best choice for large hotels and apartments.

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chiller-fan

Safe and Reliable
● Ejecting oil return design: when the unit operates under bad oil return work condition, the ejector will be automatically started up to ensure reliable oil return of unit, which can solve the oil return problem of flooded unit. 
● Oil supply design of oil pump *(optional): the oil pump will conduct auxiliary oil return under low differential pressure, which can effectively prevent faulted oil circulation of compressor when the differential pressure is insufficient, and improve reliability of compressor. 
● Multiple anti-freeze design of shell and tube: 
A. Water flowing through the heat exchange tube can prevent partial frost cracking. 
B. Adopt multi-slot tube plate design to improve hermetically-sealed construction for preventing the risk of leakage. 
C. Add water flow switch water-break protection. 
D. Adopt evaporating temperature control technology to conduct triple control for evaporating temperature, water yielding temperature of shell and tube, anti-freeze water temperature. It can ensure that the evaporating temperature inside the shell and tube is over 0℃ for preventing frost cracking of shell and tube.
● Toproof design: 
A. Hermetically sealed structure, prevent exposure of parts and components. 
B. Adopt rotproof gold aluminum foil and anticorrosive materials to make the fins, which can go through the neutral salt spray test for 2000 hours. 
C. Adopt three-layer protection design for the chassis: epoxy zinc rich primer, high build epoxy antirust paint, four fluorine carbon paint *(optional). 
D. Parts and components of pipelines adopt zinc rich primer and four fluorine fluorine carbon paint *(optional). 
E. Self-made sheet metal adopts rotproof whether resistant polyester powder sprays coating *(optional).

High Comfort Level
● Ultralow temperature cooling design *(optional): Apply control technology of inverter fan unit to conduct reliable cooling under the ambient temperature of -20℃. 
● Stepless capacity adjustment: Single system 50%-100%, dual system 25%-100%; when compressor starts up under the minimum load, the cooling capacity of unit can be stepless adjusted according to the requirement of users. Adjust refrigerant volume by stepless slide valve for matching with actual load perfectly. 
● Noise reduction and vibration damping design 
A. Low noise axial fan design: adopt the plastic fan blade made of high-efficiency low noise fiber glass with improvement of 20% and streamline ail foil design that the fan can be driven directly, which has lower noise than general fan units. 
B. Sound insulation and noise reduction design for fan *(optional): sound insulation cover is specially designed for the fan that can further reduce the noise.

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