Multiaqua CFFWA Series, Руководство по эксплуатации

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System Description & Sequence of Operation
The Multiaqua Chiller is a self-contained, air-cooled condenser, coupled with an insulated brazed plate
heat exchanger (evaporator). The system utilizes a scroll compressor to circulate refrigerant between the
condenser and heat exchanger. The refrigerant is metered into the heat exchanger with a thermostatic
expansion valve. Protecting the system are high and low pressure switches as well as a pump flow switch.
Liquid solution (water and propylene glycol) is circulated through the heat exchanger by a factory
supplied internal pump. The liquid solution flows through the heat exchanger to the system supply piping
and on to the air handlers.
A solenoid-operated, motorized valve or circulator controls the flow of the chilled liquid solution through
the air handlers. The valves or circulators can be actuated by a variety of different control schemes.
Liquid solution temperature is controlled by a chiller mounted digital electronic controls. A system
sequence of operation, individual control description, troubleshooting information and a schematic are
included in the controls section.
It must be recognized that ferrous pipe may cause acceleration deterioration of the brazed
plate heat exchanger and could void the heat exchanger warranty.
Cooling Diversity Load
Equipment sizing for a chilled liquid solution system can utilize Cooling Load Diversity. Diversity is
described as the actual amount of cooling needed (heat load) by various sections of a structure at a given
time. Conventional air conditioning systems are designed for the highest structure heat load. The
conventional system determines and selects equipment based on the peak heat load demanded by the
structure. A system sized to take advantage of diversity would determine the heat load by the time of day,
building exposure and usage. As an example the sections of a structure facing west, demand more cooling
in the afternoon, than sections facing east. The opposite of this is true in the morning, where the east
section is exposed to a higher heat load requiring more cooling. Utilizing diversity the chiller system
would adapt to the needs of each side of the structure during peak demand by delivering more cooling to
that area and less to the areas that do not need it. A structure utilizing a conventional DX system, requires
8 tons of cooling at peak load, could utilize a much smaller capacity system (potentially 4 or 5 tons) if the
system installed could take advantage of load diversity, which would supply the necessary amount of
cooling to the space, as and when needed instead of keeping a larger capacity available at all times.
Cooling load diversity can best be determined by referring to ACCA. (Air Conditioning Contractors of
America) Manual “J”, Refer to the appendix A-2, Multi-Zone Systems. ACCA’s Internet address is
http://www.acca.org/
Because of diversity a Multiaqua Chiller can serve more total air handler tonnage than chiller capacity.
For example, a 5-ton chiller may be delivering chilled liquid solution to 7 or more tons of air handler
capacity. Because of cooling load diversity, the building does not need equal amounts of cooling in each
area at the same time.
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