Powerstream Screw DC

STEPLESS CAPACITY CONTROL

Powerstream’s compact semi-hermetic screw compressors are distinguished by a further improvement in energy efficiency under full and part load conditions. As a result, these compressors exceed the international efficiency standard of compact screws with respect to the seasonally weighted energy requirements to an even higher degree than before. This results in particularly high ESEER/IPLV and SCOP values.

The cooling capacity of the compressor is controlled by a slider, which allows an adaptation of the compressor displacement to the power requirement by shifting the start of the compression process through the axial movements of the control slider. The slider, starting from the full load position (100%), can be infinitely adjusted to a nominal of 25%.

CENTRALIZED CHILLED WATER PLANT CONTROL

The control hub of Powerstream chillers is a sophisticated controller with advanced software developed for efficient operation of water-cooled chillers. It manages and optimizes the chiller’s performance, giving complete control over the system for the plant operators.

Control software can be directly linked to the existing building management system. Integration with a BMS permits the collection and analysis of the operating data of chilled water plant and helps to maintain optimal equipment settings, savings in energy, identification of trouble-prone areas, provision of maintenance schedules and the generation of safety and security alarms.

For the efficient operation of multiple units on a single chilled water plant, the sequencing software permits interlinked operation of the complete system, thus providing optimal temperature control and minimal energy consumption.

ADOPTED FOR PART LOAD CONDITIONS • R134A-OPTIMIZED

The shell and tube evaporator incorporated in Powerstream design offers extremely high evaporating temperatures for a given supply water temperature and optimized for R134a refrigerant. Heat transfer rate of the evaporator enhanced with internal refrigerant side tube grooving and optimally positioned baffles.

The tube bundle composed of a series of pre-modeled U-shaped tubes enabling the free expansion of the whole unit independently from the shell. Internal baffles in the water circuit optimize the flow whilst keeping pressure drop to a minimum. Reduced baffle spacing ensures high heat transfer at low flow rates, as well as for brine operation.

EASY OF MAINTENANCE/CLEANING • R134A-OPTIMIZED

Powerstream Screw features newly developed shell-and-tube condensers optimized for R134a refrigerant to provide the best possible efficiency. With high-performance tubes, new baffle design and shell, these condensers provide maximum efficiency with a low cost per kW, as well as a shorter length and reduced weight.

Powerstream Screw chillers are equipped with two refrigerant circuits each connected to its own shell-and-tube condensers. This design enhances reliability and allows chiller maintenance to be performed without shutting it down completely, as well as maintenance of a connected cooling tower or dry cooler. Therefore, 60% of the design capacity will remain in service during maintenance periods.

20% SAVINGS WITH INTELLIGENT EXPANSION VALVES

The electronic expansion valve (EEV) reduces the need for high head pressure when running at lower than nominal ambient conditions. EEV is controlled by a driver which regulates its opening according to the performance levels required by the system and guarantees minimal overheating based on all operating conditions. Due to the superior control characteristics of EEV, Powerstream chillers demonstrate energy savings of up to 20%.