R134a Refrigerant Water Cooled Screw Chiller High Efficiency series

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R134a Refrigerant Water Cooled Screw Chiller 

Overview

Cooling Cpacity range : 209.8-2151.5kW

Refrigerant : R134a

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Product Overview

The MARS Star II series flooded screw water-cooled chiller comes with a heritage of the spectacular design of European screw chillers, and brings together the scientific and technological achievements of EK for designing and manufacturing chiller systems for more than half a century. It uses EK efficient semi-hermetic low-noise single-screw compressors, R134a environment-friendly refrigerant, and efficient flooded evaporator, and adopts the cutting-edge AI microcomputer control technology of EK to achieve efficient operation, system reliability, and low noise. All these make EK central air conditioners the preferred choice for the central air-conditioning systems for high-end hotels, office buildings, schools, hospitals, factories, enterprises, and other large- and medium-sized public buildings and civil buildings.
 

Efficient Single Screw Technology

Symmetrical balanced compressor

EK efficient semi-hermetic low-noise single-screw compressor has one screw rotor and two star wheel rotors. This unique structure and the
adoption of cutting-edge technologies can deliver high energy efficiency.

Single-screw rotor

The single-screw rotor boasts the most-advanced technology and is processed with a high-precision special-purpose machine. The assembly is supported by 2 or 3 bearings, which are balanced to G 2.5 to effectively minimize the vibration of the compressor.

Star wheel

The star wheels are made of a carbon-reinforced material that is stable and wear-resistant. They are symmetrically arranged on both sides of the
screw rotor, so that the axial force and radial force of the screw cancel each other out. The tooth ratio of the star wheel to the rotor is designed in such a manner that the optimal thermodynamic performance can be guaranteed. The star wheel always has three teeth meshing with those of the rotor for simultaneous suction, compression and exhaust. The symmetrical structure brings ultra low vibration during compression and enables the star wheel and the screw rotor to generate double reverse acoustic waves to form an internal silencer. For this, the noise generated by the
compressor is quite low.

Stepless regulation

Equipped with quality solenoid valve assembly, the unit can achieve accurate and stepless regulation of the compressor capacity (25% to
100%). Various slide valve volume ratios are supported for many different operating conditions, to perfectly match with the actual load, ensure unit operation efficiency, and provide a comfortable environment with less energy used.

Double-layer casing

The double-layer casing made of cast iron is processed with a precision M/C machine and the processing precision is measured with a 3D precision measuring instrument to ensure that the compressor precision and gap can meet the requirement for efficient operation. Such design ensures the maximum bearing capacity and security of the unit, and also reduces noise and vibration.

Bearing

Quality high-precision bearings, combined with an excellent oil pipeline system and the inherent balanced and symmetrical structure of the compressor, can enable the axial force and radial force of the screw to cancel each other out. With less force exerted, the bearings can remain durable for over 100,000 hours.

Suction filter

The double-layer air inlet screen design ensures high strength and small pressure loss, and protects the suction safety of the compressor.

Oil pipeline safety

The oil pipeline of the compressor is equipped with a filter with an accuracy of 25 um and adsorption performance reaching Grade 13 as specified by GB/T 14309-2002. Therefore, the filter can adequately remove impurities from the oil pipeline. In addition, an oil level switch is provided to accurately detect the oil level of the unit, thus ensuring the compressor safety.

Motor

The unit features a world-renowned high-efficiency bipolar three-phase F-grade insulated inductive motor, return-refrigerantcooled compressor, and built-in PTC thermistor. It is configured with an intelligent motor protection module to protect the motor and accurately monitor the coil temperature of compressor motor, so as to ensure normal operation of the compressor. The unique internal cooling channel and the innovative cooling guide plate guarantee long-term operation of the compressor in a wider operating range.

Efficient Heat Exchange Technology

Efficient flooded evaporator

The efficient flooded evaporator with heat exchange copper tubes distributed uniformly is adopted. The copper tubes are internally and
externally reinforced, and allow for efficient heat exchange. Based on the fluid simulation design concept, professional computer simulation
software is introduced to analyze the heat exchange performance of the evaporator and achieve the optimal heat exchange performance of
the refrigerant and freezing medium with less refrigerant charged.

Efficient condenser

The condenser structure is optimized using industry-leading efficient heat exchange tubes with excellent performance, improving the heat
exchange performance. The condenser is provided with a pure reverse flow subcooling chamber with multiple turbulent flows at the bottom to
increase the subcooling degree and further improve the unit performance. The condenser is designed with a built-in efficient oil separator, and
an air equalizing plate at the top, which not only ensures stable oil return, but also reduces the impact of high-speed refrigerant gas on the
copper tubes, thus effectively reducing the noise.

Internally and externally reinforced efficient heat exchange tube

The heat exchange tubes are efficient evaporator and condenser tubes specially developed based on the principles of refrigerant boiling and condensation. Both the inner and outer surfaces have been reinforced, which greatly improves the heat exchange coefficient on both the water side and the refrigerant side, and delivers a high heat exchange efficiency.

AI Intelligent Control Technology

The control cabinet with strong current separated from weak current is equipped with an intelligent digital control center for improved efficiency.
With a large LCD professionally developed by EUROKLIMAT, it facilitates unit monitoring, data recording, and safety protection.

The chilled water temperature at the outlet is controlled as accurate as ±0.5°C, and all kinds of system sensors can accurately transfer all the
signal data to the controller so that the controller can protect the unit components in time for enhanced reliability of the unit.
The three-level password protection prevents misoperations by non-professionals and, together with the multi-protection function, ensures safe operation of the unit.

All the operating parameters and alarm records of the unit can be recorded and stored.

Unit start/stop can be controlled from a remote end and data can be transmitted through the Internet.
A 4°C to 8°C temperature difference control at inlet/outlet can be set as required.
The cooling pump, chilled pump, and cooling tower can be controlled in an interlocked manner.

Security, Stability & Green Technology

Condenser built with an oil separator

The condenser is built with an efficient oil separator with an oil separation efficiency of over 99.99%, which is not hampered even under harsh working conditions and partial load conditions. This effectively reduces the amount of oil carried by the refrigerant in the heat exchange system, and improves the heat exchange efficiency of the unit.

Triple-oil-return design

The condenser is built with an oil separator for oil return, the oil return for the evaporator is achieved by a jet pump, and that for the compressor is realized on the air suction side. This triple-oil-return design ensures normal oil supply of the compressor, and prevents oil being accumulated in the evaporator, thus guaranteeing stable, safe and reliable operation of the unit.
Oil is supplied through a pressure difference without any oil charging pump to ensure adequate lubrication of moving components
of the compressor.

Throttling by EXV

The whole series adopts internationally renowned EXVs for throttling, which can accurately control the flow of refrigerant and ensure that the unit can perform well at full or partial load. The EXV features quick response and a wide regulation range, so that the unit can make full use of the evaporator's heat exchange area to achieve the optimal heat exchange effect in any working condition, guaranteeing efficient operation of the unit, and significantly improving the unit's efficiency under partial load.

Centralized Control

The EK centralized control system for ACs adopts an industry-leading control solution, and applies to the freezing pump, cooling pump and
cooling tower control system solutions. Control and monitoring can be implemented simultaneously based on the main Web browser
network of Microsoft.

Specification