ESIE10-01 General Outline
Part 1 – System Outline 1–5
3
1
4
5
1.2 Features
Low operating cost EWAD is the result of careful design, aimed to optimizing the energy efficiency of the chillers, with the
objective of bringing down operating costs and improving profitability, effectiveness and economical
management. The EWAD chillers use the New very high efficiency McQuay single rotor screw
compressor design, large condenser coil surface area for maximum heat transfer and low discharge
pressure, advanced technology condenser fans, a single-pass pure conterflow shell&tube
direct-expansion evaporator with low refrigerant pressure drops.
Low operating
sound levels
Very low noise levels both at full load and part load conditions are achieved by the latest compressor
design that use a single main rotor with two adjacent rotating composite gaterotors making gas flow
velocities and subsequent noise levels among the lowest available, by a unique new fan that moves
large volume of air at exceptionally low sound levels and by the virtually vibration-free operation.
Outstanding
reliability
The EWAD chillers have two or three truly independent refrigerant circuits depending from the size, in
order to assure maximum safety for any maintenance, whether planned or not. They are equipped with
a rugged compressor design with advanced composite compressor gaterotors material, a proactive
control logic and are full factory-run-tested to optimized trouble-free operation.
Infinite capacity
control
Cooling capacity control is infinitely variable by means of a single screw asymmetric compressor
controlled by microprocessor system. Each unit has infinitely variable capacity control from 100%
down to 12% (two compressor unit), down to 7% (three compressors units). This modulation allows
the compressor capacity to exactly match the building cooling load without any leaving evaporator
water temperature fluctuation. This chilled water temperature fluctuation is avoided only with a
stepless control.
With a compressor load step control in fact, the compressor capacity, at partial loads, will be too high
or too low compared to the building cooling load. The result is a decrease in chiller energy costs,
particularly at the part-load conditions at which the chiller operates most of the time.
Units with stepless regulation offer benefits that the units with step regulation are unable to match. The
ability to follow the system energy demand at any time and the possibility to provide steady outlet water
temperature without deviations from the set-point, are the two points that allow you to understand how
the optimum operating conditions of a system can be met only through the use of a unit with step-less
regulation.
Building Load
Compressor Load
100
75
9
8
6
5
7
9
8
6
5
7
time
leaving water
temperature
[°C]
% cooling capacity
Building Load
Compressor Load
ELWT fluctuation with steps capacity control (4 steps)
100
75
9
8
6
5
7
9
8
6
5
7
time
leaving water
temperature
[°C]
% cooling capacity
To Next Page
Loading...
Need help?
General