Vfds For Subpumps And Gensets

[Mher]

Dear Experts.

I am conducting a study on a big irrigation site with 10 submersible pumps installed (ranges from 180hp to 225hp).

The pumps are currently driven by individual diesel gensets and started with reactor starters.

Each genset is only 50% loaded on rated pump speed.

Current power factors range from 0.83 to 0.87 (seen on the genset panels).

Diesel consumption costs are very big (fuel consumption ranges are 41 to 45 Liters/Hour)

 

In order to reduce the diesel consumption my first suggestion will be the following.

Operate 2 closely located pumps on one genset.

In order to achieve this the following steps will be adopted:

 

1) Install VFDs on the pump/motors to solve the issue of starting KVA problem (with 2 pumps on one genset).

2) Start the pumps sequentially.

3) Reduce pump speeds by the VFDs (as long as TDH is met) to reduce the KW drawn by each pump.

This will be done at the expense of slightly (tolerated) reduced flow of water.

4) High Input power factor of the VFDs will reduce current drawn from the gensets.

 

Optimum target is to reach 75-80% genset loading which will reduce the diesel consumption dramatically (pumps run at around 10 to hours per day).

 

Will the suggested solution work?

Do I miss something?

 

Thank you in advance.