# Piping System Design

1. Dec 5, 2013

### rogueDNA

1. The problem statement, all variables and given/known data

Piping System Design Problem​

The design of a piping system is required to deliver chilled water to a four-story engineering design office building. The chiller is to be placed in the basement of the building. Chilled water is to be delivered to the air handling units (AHU) on the various floors. The head loss through the chiller is 22Q2 where Q is in CFS and the head loss is in lbf-ft/lbm. The cooling fluid leaves the chiller at 45ºF returning to the chiller at 60ºF. Because of a computer center, the cooling load of the first floor is different from the remaining three floors. Therefore, the flow to floors 2,3, and 4 is 50 GPM, and use 1-AHU per floor, and 100 GPM for the first floor and uses two AHUs in parallel. The AHUs are located near the center of each floor, and have a head loss of 155Q2 where Q is in CFS and the head loss is in lbf-ft/lbm. Design the system for water as working fluid (note that in many occasions, an antifreeze is required).

The following specifications must be met:

1 Provide valves to isolate each AHU.
2 Provide valves to isolate supply and return lines.
3 Avoid pipe velocities in excess of 10ft/s, while maintaining the flow turbulent.
4 All pipes are to be schedule 40.

Determine the following:

1. Sketch the actual piping system and briefly describe rationale for design and mechanism to balance the system (10 pts).
2. Specify lengths of each pipe and diameters (To reduce complexity, use a minimum of three diameters; one for supply and return, one for floor 1, and one for the remaining floors). (5 pts).
3. Description and location of each valve (5 pts).
4. Flow rates in GPM for each floor (5 pts).
5. Increase in head loss and total flow rate for the pump (s) to be used in ft and GPM, respectively (10 pts).
6. Choose the appropriate pump (s) for the system from Goulds Reference or any other credible vendor, preferably for a rotor speed of 1,750 RPM and specify the total pumping power required (5 pts.)
7. Find the pumps’ and system's operating points (10 pts.).

Synthetize all analysis, calculations and drawings. Use the following attached drawing as reference.

2. Relevant equations

Reynolds Number to determine if flow is laminar/turbulent
Coleman Equation to calculate friction factor

3. The attempt at a solution

I have tried modeling this in FLUENT software but I can not really understand it, I am new to that software. I'm hoping somebody can provide some guidance on how to approach this problem by doing it on paper. I'm a bit confused by the english system of units used as I'm used to working in metric, but that's a small issue. Any help is kindly appreciated.
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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