IBM Rear Door Heat eXchanger V2, Руководство по установке и обслуживанию

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Attention: To help maintain optimum performance of the Rear Door Heat
eXchanger and provide proper cooling for all rack components, you must always
take the following precautions:
v Install filler panels over all unoccupied bays.
v
Route signal cables at the rear of the rack so that they enter or exit the cabinet
through the top and bottom air baffles.
v
Bundle signal cables together in a rectangle so that the upper and lower
air-baffle sliders are closed as far as possible. Do not bundle signal cables
together in a circular formation. For more information, see “Routing cables
through the upper and lower air baffles” on page 42.
The following illustration shows the typical performance of the heat exchanger, 30
kW heat load.
* As described in “Water-supply requirements for secondary loops” on page 13, a
given water temperature may be used only if the system that is supplying the water
is able to measure the room dew point and automatically adjust the water
temperature accordingly. Otherwise, the water temperature must be above the
maximum dew point that is allowed at that data center installation.
140
130
120
110
100
90
80
70
60
50
% heat removal as function of water temperature and flow rate for
given rack power, rack inlet temperature, and rack air flow rate
4 10 12 14
% heat remo
va
l
Water flow rate (gpm)
Water
temperature
12°C *
14°C *
16°C *
18°C *
20°C *
6 8
22°C *
24°C *
Airflow
(cfm) = 2500
Rack Power
(W) = 30000
Tinlet, air
(C) = 27
Figure 2. Typical performance of the heat exchanger, 30 kW heat load
Chapter 2. Heat exchanger planning, specifications, and requirements
7