Extracting energy from low pressure flow

[AdamJ2]

Hello Everyone,

I would really appreciate if anyone has ideas on how to extract energy from low pressure flow. The situation is that I have horizontal water flow in a pipe with a working pressure of 1.5 bar and I need to figure a way to convert some of the flow into a useful energy form such mechanical (rotation) or electrical. My first thought was to use a hydraulic motor but I quickly realise that these devices only operate at at least 10 bar. I'd grateful for any help.

 

[hydtools]

A hydroelectric generator.

Ted

 

[LittleInch]

Some form of waterwheel or vane pump running backwards. But you need a lot of flow to get anything useful.

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[IRstuff]

Along the same lines, a waterwheel

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[LittleInch]

Just Google low head hydropower

E.g.

https://www.renewablesfirst.co.uk/h...earning-centre/head-and-flow-detailed-review/

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[Jacc]

Pneumatic motors are designed to run on low pressure. Parker and Globe are two brands.
They probably don’t like water though.

 

[itsmoked]

Maybe this fits?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[EngineerTex]

How much flow do you have? Can you accelerate the water with a nozzle and use a pelton turbine?

https://youtu.be/uN_yPUC8vHM

Do you have enough flow to be able to boost pressure with a ram pump, store the higher pressure in a tank and then extract energy from that with a higher-pressure system?

https://science.howstuffworks.com/transport/engines-equipment/question318.htm

What would you use if you had flow with a higher pressure?

What is the application? Personal? Work? Hobby?

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[AdamJ2]

Hello everyone,

many thanks for everyone who provided suggestions, sorry for not replying I was quite ill and couldn't work for the past few days.

hydtools, IRSTUFF & littleInch,
I quite like this suggestion. although I couldn't find a suitable waterwheel I am going with a water trubine (shown in the photo) which hopefully will do the trick. Out of curiosity, does anyone know what happens if I use a 10W water turbine with a flow powerful enough to power a 150W, would there be H&S risk?

Jacc,
thanks a lot for the suggestion, I;ve looked into this but I don' think it will work with water.

itsmoked,
great idea, I'll investigate this prospect further but I think my flow might be too weak.

EngineeringTex,
thanks a lot for you comment, unfortunately I can't use a nozzle in my application. I quite like your idea with the pump and tank and I'll see how I can apply it. I'm currently using a small tank to reduce flow fluctuations but I haven't considered using a pump so thanks. If I had a higher pressure I'd simply use a hydraulic motor but all the ones I found only operate relatively high pressures (at least 10-30 bars). My project is work related so I have a budget to try things out but it would of course be best to get it right the first time.

thanks again everyone

 

[LittleInch]

You just won't get the flow.

You have as you say 1.5 bar - that 0.15MPa. When you look up those minim wheels you'll get about 10V if you're lucky and virtually no current.

https://www.aliexpress.com/item/DC-...water-flow-generator-F50-80V/32235880094.html

1.5 bar is what you get from most domestic supplies in Europe or the UK - maybe more in the US but I was astounded by how many options came up for the F50 80V pump.

An interesting demo here:

https://www.youtube.com/watch?v=cVT70JNO3dU

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Also: If you get a response it's polite to respond to it.

 

[AdamJ2]

Hi LittleInch,

yeah I agree seems like the wheel won't reach anywhere near the advertised 10W which isn't much to begin with. nonetheless I've ordered a couple since they're very much and I'll see how it goes. Also thanks for sharing the video demo, I didn't realise these water turbines were actually popular.

 

[LittleInch]

Looks like people are trying to get power from their domestic water supply.

The efficiency looks terrible so you will use a LOT of water.

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Also: If you get a response it's polite to respond to it.

 

[chicopee]

I don't have any idea on the amount of water that is available, however, research the Banki hydroelectric cross flow turbine. There is a fair amount of information and research on this turbine.