Civil Engineering Reference
In-Depth Information
Fig. 8.1
Chilled water system
the desired functions in evaporators and condensers. Using a central chiller plant
instead of having multiple cooling devices throughout the building helps to limit the
existence of the refrigerant in a central location. This means monitoring, controlling
and evacuating expense of the stored refrigerant in a chiller assembly in case of
occurrence of refrigerant leak accident in the site can be limited to a central location
instead of multiple locations.
The main sources of energy consumption in air- or water-cooled chilled water
systems are power required for running the chiller (compressor), power required for
running the fan at cooling tower (Condenser fans in air cooled system), and power
required to run the pumps. Heat transfer to and from the pipes can indirectly increase
the energy consumption of the system also. The small energy consumed by low
voltage power provided for control valves is another source of energy consumption.
There is always electrical power consumption for heat tracing the water piping out-
side the heated mechanical rooms, and protecting the cooling tower basins from
freezing. It should be noted here that energy consumers of the airside of the system
will be discussed later in this chapter.
8.5
Heating Systems (Boilers)
A boiler by defi nition is a closed heating appliance that its function is to provide
either hot water or steam for power generation, processing, and space heating. It is
common to subcategorize the boilers to low pressure and high pressure. For a hot
