Features of screw chillers

The screw chiller is a central air conditioning equipment host with a semi-enclosed twin-screw compressor as the core and refrigerant as the carrier. When cooling, it uses air or water as the cold source, and releases the heat on the load side to the cold source through the refrigeration cycle, thereby cooling and cooling the load side; when heating, the air-cooled unit uses air as the heat source, extracts the heat from the heat source side through the refrigeration cycle and releases it to the load side, thereby heating and heating the load side; the unit uses a high-quality imported brand twin-screw compressor, whose moving parts are only about 1/10 of the reciprocating compressor, and uses a total of 11 high-precision Swedish SKF bearings in the radial and axial directions. At the same time, it is combined with an axial thrust balance drum to effectively balance the axial load. The rotor is in continuous operation, and the vibration is only about 1/5 of that of the reciprocating type; there is no need to consider shock absorption when installing the whole machine; at the same time, it also ensures the long-term stable operation of the unit; the single compressor can choose a four-stage capacity adjustment method for energy saving, which can save energy as much as possible under partial load conditions while reducing the frequent start-up of the compressor, thereby extending the service life of the unit; combined with the highly intelligent control of PLC , so that the unit can achieve the best energy efficiency ratio regardless of full load or partial load, significantly reducing the user's operating costs; through the combination of multiple compressors, more detailed multi-stage capacity adjustment can be achieved;

The screw chiller can also adopt 25%-100% stepless capacity adjustment, but in order to ensure the long-term operation safety of the unit, it cannot be used in extremely harsh environments

and long-term operation at less than 50% of the nominal cooling capacity of the unit. Please confirm with our technical department before ordering;

The oil return method adopted by the screw unit is differential pressure return, without the need for an external oil pump, which greatly reduces the failure rate of the oil supply system; the compressor adopts an advanced three-stage

oil filter, which makes the oil filtration rate as high as 99.7%, which greatly guarantees the oil return of the compressor;

For units with multiple compressor heads, the microcomputer will automatically memorize the operating time of each compressor, and the compressor with less operating time will be activated first at the next startup; Similarly, when it is necessary to unload the operation, the unit with longer operating time will be unloaded first to achieve balanced operation of each compressor and extend the service life of the whole machine; In order to more fully separate the refrigeration oil from the refrigerant, the low-temperature chiller is equipped with an external centrifugal high-efficiency oil separator, which can greatly reduce the refrigeration oil retained in the evaporator due to low temperature, ensure the safety of the compressor lubrication system, and also improve the heat exchange effect of the evaporator; The screw air-cooled chiller accurately designs the aluminum sheet spacing to minimize the chance of frosting. Comprehensive analysis and judgment based on time, temperature and pressure are fully combined to truly realize on-demand defrosting, and each defrost is thorough, extending the defrosting interval. Screw chillers are widely used in various fields such as central air conditioning and industrial cooling. When used for industrial cooling, the low-temperature water produced by the chiller can be directly sent to the equipment and containers that need to be cooled. However, in order to control the precise and stable water temperature, the water outlet of the chiller is often sent to the buffer pool before entering the equipment or container that needs to be cooled. Screw chillers can be used for various low-temperature cooling in industrial cooling. After adding appropriate antifreeze to the chilled water side, the outlet water temperature can be 0 to -35°C to meet different industrial cooling requirements; the commonly used antifreeze solvents are ethylene glycol, sodium chloride and calcium chloride solutions. In application, it is recommended that customers set different concentrations of antifreeze solutions according to the outlet water temperature. Please refer to the attached table for the freezing points of various solutions; Screw chillers that fully follow the reverse Carnot cycle can obtain 3-4kW of cooling capacity or heating capacity under normal circumstances with an input of 1kW of electricity, and their operating costs will be more advantageous than other air conditioning methods.

Air-cooled chillers are easy to install and maintain, eliminating the need for cooling tower systems. Only chilled water pipes need to be connected. They do not occupy a dedicated machine room, have very few vulnerable parts, and have a low maintenance rate. Water-cooled chillers have high refrigeration efficiency, consume less electricity to produce the same cooling capacity, and have relatively less noise during operation. In order to better protect the atmosphere, in addition to HCFC22, refrigeration and air-conditioning equipment using green and environmentally friendly refrigerant media such as HFC407C and HFC134a can also be produced; the unit adopts advanced PLC control, which is highly intelligent, with built-in multi-stage timer switch control intelligent mode, which can realize automatic operation without guarding all day; the control system has a linkage control of the water pump reserved inside; and various protection functions are complete.

Product options

■Adopting internationally renowned brand twin-screw compressor, it has the characteristics of high efficiency, low noise, low wear and long service life.

■Adopting 4-stage energy adjustment or 0%-100% stepless automatic adjustment.

■Adopting German Siemens PLC programmable controller, LCD touch screen, Chinese and English human-machine interface.

■Complete fault protection: high and low pressure protection, exhaust protection, oil level protection, water flow protection, reverse missing protection, chilled water antifreeze protection, cooling water over-high protection, etc.

■Ultra-wide chilled water temperature variable range, meeting the requirements of low-temperature industrial use.

Product options

1.Salt water evaporator

2.Stepless energy regulation

3.Whole heat recovery/partial heat recovery

4.Pump/cooling tower control

5.Special power supply

6.Internet of Things

Products features

■Twin screw compressor brand is employed,with high effciency ,low noise level,less wearing and long operation time.

■Four stage volume control or0%-100% automatic regula.

■Use PLC microcomputer control from GermanySIEMENS,With LCD touch screen,both English and Chinses human-machina intertace.

■Complete breakdown protection:high and low pressure protection,air discharge protection,oil level protection,water flow protection,reverse and lack phase protection,chilled water anti-freezing protection,cooling water overtop protection

■Wider range of variable chilled water temperature to meet the low temperature industrial requirements.

Product specification

Refrigerant:R22/R134a /R407C

Evaporator/condenser max water pressure drop:1.0MPa

Evaporator:Fouling Fouling factor 0.018 ㎡’℃/KW

Condenser:Fouling factor 0.044 m’℃/KW

Power supply:380/3P/50HZ

Allowable voltage fluctuate: ±5%

Allowable frequency fluctuate: ±2%

Compressor

Select semi-closed 5:6asymmetric twin-screw compressor from world-renownedbrand ,The possiblity of shaft seal leakoge is zero.Using a rotating exhaust design,the latest development of the fourth generation line,optimize the circumferencespeed, excellent design of gear so that the unit has higher compression efficiency,Motor chamber compression chamber integrally cast,highprecision.Double pressure compensated rotor housing, very strong,no expansioneven in the state of high pressure,and it effectively reduces the noise.

Heat exchanger

The condenser and evaporator of this series unit adopts shell and tuble heat exchanger,using new high efficient heat exchanger structure.heat exchanger adopts themost advanced and effcient heat exchanger tube bundle with, unique geometric characteristics and,enhanced tube nucleate boiling required vaporization core, strengthen the fluid in the tube and delay perturbationat the same time,the waterside fouling,heat transfer enhancement,the inside wall in order to get the bestperformance,comparede to the previous design,the unique design of the heattransferefficiency is increased by30%.Evaporator evaporation tube with inner screw groove on outer concave tooth enhancedheat transfer technology,condenser tube with inner screw groove cutter teethtechnology,improves the evaporator and condenser heat transfer efficiency andtheevaporation temperature,and ultimately improve the energy effincy ratiofor the unit.

PLC

A good all-Chinese interactive interface is to achieve automatic control function before the LCD display real-time statues of the machine work, precise monitoringunit operating at optimum state, the touch panel sealed, waterproof, dustproof,corrosion-resistant, long-key life. Equipped with refrigerant pumps, cooling waterpumps and cooling tower fan interlock control function.

Low temperature chillers

NLW series of low temperature chillers based on well-known brands asthe host semi-hermetic screw com pressor, built-in suction filter, oil filter,oil separators, safety valve and protection module, with no leakage, low noise, stable operation.