Table of Contents
Advertisement
The flow rate of the water in the system must be in the range of 23 - 57 liters (6 - 15 gallons) per minute.
Pressure drop versus flow rate for heat exchangers (including quick-connect couplings) is defined as
approximately 103 kPa (15 psi) at 57 liters (15 gallons) per minute.
• Water volume limits
The heat exchanger holds approximately 9 liters (2.4 gallons). Fifteen meters (50 ft) of 19 mm (0.75 in.)
supply and return hoses hold approximately 9.4 liters (2.5 gallons). To minimize exposure to flooding in the
event of leaks, the entire product cooling system (heat exchanger, supply hose, and return hose),
excluding any reservoir tank, must have a maximum 18.4 liters (4.8 gallons) of water. This is a cautionary
statement, not a functional requirement. Also consider using leak detection methods on the secondary
loop that supplies water to the heat exchanger.
• Air exposure
The secondary cooling loop is a closed loop, with no continuous exposure to room air. After you fill the
loop, remove all air from the loop. An air bleed valve is provided at the top of a heat exchanger manifold
for purging all air from the system.
Water delivery specifications for secondary loops
This section includes the various hardware components that make up the delivery system secondary loop
that provides the chilled, conditioned water to the heat exchanger. The delivery system includes pipes,
hoses, and the required connection hardware to connect the hoses to the heat exchanger. Hose
management in raised-floor and non-raised-floor environments is also described.
The heat exchanger can remove 100% or more of the heat load from an individual rack when it is running
under optimum conditions.
The primary cooling loop is considered to be the building chilled-water supply or a modular chiller unit. The
primary loop must not be used as a direct source of coolant for the heat exchanger.
The main purpose of this topic is to provide examples of typical methods of secondary loop setup and
operating characteristics that are needed to provide an adequate, safe supply of water to the heat
exchanger.
Attention: The overpressure safety device must meet the following requirements:
• Comply with ISO 4126-1 (Information about obtaining this document is at https://webstore.ansi.org/
Standards/ISO/ISO41262013. Search on document number iso 4126-1.)
• Be installed so that it is easily accessed for inspection, maintenance, and repair.
• Be connected as close as possible to the device that it is intended to protect.
• Be adjustable only with the use of a tool.
• Have a discharge opening that is directed so that discharged water or fluid will not create a hazard or be
directed toward any person.
• Be of adequate discharge capacity to ensure that the maximum working pressure is not exceeded.
• Be installed without a shutoff valve between the overpressure safety device and the protected device.
The following figures show typical cooling solutions with the most flexibility possible. Consider the following
guidelines before planning your solution.
• A method for monitoring and setting the total flow rate delivered to all of the heat exchangers is required.
This can be a discrete flowmeter that is built into the flow loop or a flowmeter within the secondary loop of
the coolant distribution unit (CDU).
• After you set the total flow rate for all of the heat exchangers by using a flowmeter as previously
described, it is important to design the plumbing so that it provides the flow rate that you want for each
heat exchanger and provides a way to verify the flow rate. Figure 5 on page 16 through Figure 8 on page
54
ThinkSystem Heavy Duty Full Depth 42U Rack Cabinet User Guide
Advertisement
Table of Contents
