Further Saving with Smart Pumping System

Power savings can accrue by modulating the flow until an optimum temperature balance is achieved among the tower inlet and outlet temperatures and the wet bulb temperature.

If the cooling system is lightly-loaded, as indicated by a tower inlet approaching the wet-bulb, turn the fans off and the flow down until the tower inlet temperature rises.

Now, who can do the maths?

This would be a question to pose to the seller of the product, not strangers who have no idea of the system capacity or current configuration.

If the cooling tower is equipped with a fan, a VFD will likely save more energy with the fan than with the pump. With a fan, nearly the full range of the VFD can be used (say 10-100%). With a pump, the VFD can be slowed only to the point where the pump will still lift to the static height involved. This may be something like 85% of full speed. This can still save energy, but be aware of this limitation.

You said that you already have a VFD on the pump correct? If so then it's a safe bet that someone also installed something that will tell the VFD what speed to run, usually on a cooling tower it is a wet bulb temperature sensor and feedback system as PWSlack mentioned. If not, then someone was foolish about installing a VFD.

So then what is it that you are calling a "smart pumping system"? Is that another thing that someone is proposing that you add to this? That is not an industry standard term, more likely it is some manufacturer's trade name for a control system product and without knowing anything about it we cannot comment further. If you want help, don't make us guess. Spell it out.

The technical data received from the plant manager states ,A smart pumping system consists of a pump ,VFD, microprocessor, and special software.The pump can be any standard centrifugal pump fitted with instruementation to measure suction pressure, suction temperature,discharge pressure and pump flow.All of the hydraulic characteristics of the pump, fluid characteristics, user control parameters and pump control software reside on the microprocessor of the smart controller. The pump control software enables the controller to sense pump and process conditions and react accordingly.These system can be designed to maintain constant values of speed, capacity, pressure, level or PH and can be controlled either locally or through a distructive control system ( DCS ).

Hope the above detail will be sufficient to find some clue to my question

Well, were getting closer. But do you ALREADY have the VFD? If so, what is ALREADY giving it a speed command? Chances are, something is ALREADY doing this, now someone else is trying to sell it to you again. You asked if it will benefit you to add some other control system, yet we don't know that you don't already have one! Start with what you know, don't just guess.

The other possibility is that you already have a VFD, but someone is just manually controlling the speed. That seems ridiculous, but it happens. If that is the case, then for sure a "smart pumping system" would be an enormous benefit.

The point I am trying to get across is that if someone already went to the trouble of putting in a VFD, it was most likely just a part of an overall system to save energy. For example all of the things you are describing might already be taking place in your DCS, it isn't that difficult to do. Sometimes people try to sell things that they say are "smart" packaged control systems but end up just being redundant to existing systems, but with fancier names. Don't be fooled.

Thanks for your excellent and technically sound answer.The plant pumps and supply as well as exhaust fans all are running on star delta operation. Our organisation which also deals in energy audit, the plant manager has asked us to guide him regarding smart pump system. He wants to go for smart pumping system for the existing pumps and to buy this system for his new plant. Your further guidelines will be of immense value to the plant so do pass on your valuable points thanks.