Hi,
Currently, we are asked to calculate power consumption in kWh for specific pumps in order to lay out a plan to be more energy efficient.
I have started with the pump curve attached. The pump is used for NGLs with the original operating point at 620 GPM, 5200 ft of head and 76% efficiency (around 600 BHP) - Red Cloud. Electrical consumption has been calculated as follows:
Power = 600 BHP = 450 kW
E Consumption = 600 BHP x 0.75 x 1.1 x 24h/day = 11,880 kWh/day
The factor 1.1 is to account for electrical motor and parts losses
Currently the pump is running at 400 GPM with corresponding 500 BHP and around 65% efficiency (blue cloud).
Power = 500 BHP = 375 kW
E consumption = 500 BHP x 0.75 x 1.1 x 24h/day = 9,900 kWh/day
My understanding is that, as per pump affinity laws, power is proportional to the flowrate cube. Is that a correct approach? Electrical motor is a single speed motor (3560 RPM)
Thanks in advance
Sherif