Hydraulic vs. electrically driven pumps?

[nocam1334]

What are some of the pros and cons of a hydraulic driven pump vs. an electrically driven pump (from a designer's point of view)?

 

[JRLAKE]

One that sticks out to me is the environment. If you don't want to run electrical lines in an explosive or wet area hydraulic driven pumps are a good alternative.

For example, I see hydraulic driven pumps used a lot in mining applications.

 

[nocam1334]

How about with respect to:

1) Weight
2) Starting Time
3) Noise
4) Maintenance

 

[nocam1334]

I have some more info. I am relative newbie at design, and I am looking into designing a submersible pump that is electrically driven (an electric motor directly coupled to the submersible pump). I actually have a hydraulically driven model to go by, so I would probably just need to figure out what it will take to adapt it to be electrically driven.

One question I have is whether the electric motor would overheat in a mud drilling application. Anyone have any experience in this area?

 

[hydtools]

If you have a hydraulic driven pump, why do you want to change it to electric?

Ted

 

[nocam1334]

It's actually customer request, a particular customer likes the pump itself but would prefer it to be electrically driven.

 

[hydtools]

You need to match the impeller speed and have enough horsepower to deliver current pump performance.

Ted

 

[Artisi]

"nocam1334 (Mechanical) 31 Jul 08 15:52
I have some more info. I am relative newbie at design, and I am looking into designing a submersible pump that is electrically driven (an electric motor directly coupled to the submersible pump). ......."


With many manufacturers throughout the world having invested a small fortune in development of electric submersible pumps, why would you want to reinvent the wheel?

My opinion is you are wasting your time and unlikely to succeed. Where will you get the motor from, how will you cool it during operation, etc etc etc.

 

[ScottyUK]

I suspect that the hydraulic motor will be smaller and lighter than the electric one of the same power rating and shaft speed, particularly as shaft speed decreases. In a submersible pump application I can imagine that trying to incorporate a larger motor into an existing design will lead to all sorts of complications and compromises such as increased OD of the pump canister, but I ain't a pump designer so maybe I'm wrong.

If an electric cable breaks down in the hole it trips a supply breaker. If a hydraulic hose fails it ejects high pressure oil into whatever hole you're drilling: probably not ideal the hole was a well for potable water.


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If we learn from our mistakes I'm getting a great education!

 

[JRLAKE]

I seriously doubt you'll find an electric motor to adapt to the existing pump frame. You need to buy a new pump. First you need to make sure it will work in the application. Call your local submersible pump vendor. I recommend Gorman Rupp or Flygt.

 

[EdStainless]

One of the biggest problems with electric subs is cooling. If this is a low speed unit then stay hydr.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[hydromech]

More and more automotive OEMs are going to hydrostatic drives for fans and auxilary rotary functions.

The power to weight ratio of a hydraulic motor is far in excess of an electric one.

Your customer needs to be re-educated about the benefits of hydraulics over electrical actuators.

Direct him here and we will show him the error of his ways!

 

[Unotec]

You are not talking of a downhole mud motor, are you?

<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying ” Damn that was fun!” - Unknown>>

 

[ScottyUK]

hydromech,

That's possibly true IF you have an available source of power for the hydraulic pump to drive the motor. If you have to drive the hydraulic pump with an electric motor then the power/weight ratio of the system is much worse than the all electric design. Of course if saving weight in a specific part of the system is advantageous then hydraulics might still be better.


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If we learn from our mistakes I'm getting a great education!

 

[hydromech]

Scotty...

You are of course correct, what nutter would install a complete hydraulic system just to run a small motor.

It really only applies to mobile equipment.

Adrian

 

[Apakrat]

nocam1334 --- Something Ya might want to think about.

The electric motor will need a bottom hole “dump valve” arrangement or an electric motor several times more hp for shutdown times when discharge pipe is loaded to the top of hole.

Irrigation water well people seem to wanna sell electric motors 4 times required head needs.

A hydraulic motor will usually start and operate at excess of it’s stated design limit loads.

 

[nocam1334]

Thanks for all the info guys. We are going back to the customer and telling him electric is probably not the way to go in this situation.

 

[HPMach]

Original selection of drive will primarily depends on availability of power source & suitability. I would say Hydraulic system is complicated, if it is for continuos duty and controls are required.

 

[heidenwag]

We manufacture a lot of electric AC motors for downhole drilling applications. The motor usually drives the hydraulic pump and works at 200 Deg C. The customers prefer 2 phase motors to minimize the cable length which can be up 20000 feet long. See

http://www.ducommun.com/motors-resolvers.html.