Pressure drop over double parallel system

In summary, the system you described has pipes that carry 24 L/min of water at 60 degrees through 3 manifolds, which then distribute the water over 8 heat exchangers. Each heat exchanger requires 1 L/min and has a resistance of about 1.333 KPa at that flow. The manifolds have a resistance of 1.85 KPa, and the main distribution tubes are 4 meters long at 20mm and carry the full load of 24 L/min, adding up to a total resistance of 3.53 KPa. Overall, the total pressure drop over the system is 6.71 KPa, considering that the resistances of all the components are in parallel.
  • #1
Anansi
I have a system where pipes run 24l L/min of water @60 degrees through 3 manifolds and those manifolds distribute the water over 8 heat exchangers. Every heat exchanger requires 1 L/min, and has a resistance of about 1.333 KPa per heat exchanger at that flow (2 meter @ 9mm diameter + 2 connectors with CV=0.85). Every manifold has a resistance of 1.85 KPa (2 connectors with CV=5.77, resistance of tube is negligible here). The main distribution tubes are 4 meters long at 20mm and carry the full load of 24 L/min that should add up to about 3.53 KPa.

As far as I can tell I need to only count the resistance of all these parts once because they are parallel so the total pressure drop over the system is 1.333+1.85+3.53=6.71 KPa. But its rather important to select the right pump for the system so would really like a verification for this.
 
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  • #2
Anansi said:
As far as I can tell I need to only count the resistance of all these parts once because they are parallel...
Your analysis looks good to me (without commenting on the numeric values).
 

1. What is pressure drop over a double parallel system?

The pressure drop over a double parallel system is the decrease in pressure that occurs when a fluid flows through two parallel paths in a system. It can also be referred to as the pressure loss or pressure difference.

2. How is pressure drop over a double parallel system calculated?

The pressure drop over a double parallel system can be calculated using the Darcy-Weisbach equation, which takes into account factors such as fluid viscosity, flow rate, and pipe geometry. Alternatively, it can be measured experimentally using pressure gauges.

3. What causes pressure drop over a double parallel system?

The primary cause of pressure drop over a double parallel system is friction between the fluid and the walls of the pipes. This friction results in energy being lost, which leads to a decrease in pressure along the flow path. Other factors that can contribute to pressure drop include changes in pipe diameter and fluid density.

4. How does pressure drop affect the flow rate in a double parallel system?

As pressure drop increases, the flow rate in a double parallel system decreases. This is because a higher pressure drop means a greater loss of energy, which reduces the driving force for the fluid to flow through the system. Therefore, a larger pressure difference is needed to maintain the same flow rate.

5. How can pressure drop over a double parallel system be minimized?

To minimize pressure drop over a double parallel system, the pipes should have a larger diameter, as this reduces the surface area for friction to occur. Additionally, using smoother pipes and reducing the flow rate can also help to decrease pressure drop. Proper maintenance and cleaning of the pipes can also prevent buildup and reduce pressure drop.

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