Water pump system in Chiller work

Article details

Water pump system in Chiller work

It is one of the key points of the Chilled Water System.

This helps deliver cold water from the Chiller to the AHU/FCU for heat exchange. and send water back into

Chiller again for new cooling.

🔧 Water pump system in Chiller work can be divided into 3 main system.
1. Chilled Water Pump (CHWP)
 • Duties: Deliver cold water from Chiller to AHU / FCU.
 • Return to Chiller after heat exchange.
 • Used with office building systems, hospitals, department stores.

2. Condenser Water Pump (CWP)
 • Function: Send coolant water to exchange heat with the Chiller's condenser.
 • Then bring it back to release heat at the Cooling Tower.
 • Required in systems using Water-Cooled Chillers.

3. Primary / Secondary Pump System (only in large systems)
 • Primary Pump: circulates water only in the Chiller loop.
 • Secondary Pump: delivers cold water to use in the AHU / FCU.
 • Separate circuits for flexibility in the operation of multiple chillers.

🔄 Easy to understand work diagram
[Cooling Tower]
       ↓↑
[Condenser Water Pump]
       ↓↑
[Water-Cooled Chiller]
       ↓↑
[Chilled Water Pump] ──→ [AHU / FCU] ──→ Return to Chiller.

Or if using the Primary/Secondary

[Primary CHWP] ↔ [Chiller] ↔ [Secondary CHWP] → [AHU/FCU]

💡 Techniques you should know
 • Use VFD (Variable Frequency Drive) to control the pump to reduce energy during low load periods.
 • Install Check Valve and Balance Valve to prevent water backflow and control Flow.
 • Large systems use a Differential Pressure Sensor to control the pressure of the water in the pipe.

🧊 Example of selecting a pump size
 • Flow rate (Q): Calculated from cooling load (RT).
Q = \frac{\text{RT} \times 3.517}{\text{ΔT} \times 4.186}
Or roughly:
Q \approx \text{RT} \times 2.4 \, \text{(LPM)}
 • Head (H): Calculated according to pipe length + friction loss + equipment.

📌 Short summary
The pump serves the system.
CHWP circulates cold water in every system.
CWP circulates coolant, only water-cooled.
Primary/Secondary Separate circuits, working independently, large system