Muzzer Ward

Thanks for all the awesome insights guys. I've got the second pipe installed and put pressure gauges on both so now know with more accuracy the pressures/heads.

North stream static pressure is 113psi, so the head calculates out at 79m. Dynamic pressure with a 1.5l/s flow generating 400w is 100psi.

West stream static pressure is 99psi, so a head of 69m.

The next job is to get a y-junction and combine the two pipes, add another pressure gauge and test the flow.

I'm thinking for the two 50mm pipes an 80mm diameter junction should be good. Also, 80mm diameter seems to be a common input for a lot of hydros on the market. It'll be interesting if I can even get such a junction locally, probably not something often used.

I'll post the results here for those interested.

Thank for the quick replies. I'm upgrading the turbine so it will be capable of extra water input. Ideally I would upgrade to two jets but the turbines I'm interested in are only available in single jet below 3kw, and I'm looking at only 1-2kw. Which is why I'll be wanting to combine the two streams into one input.

So summing up Mike, you think 85 psi is the likely outcome.

Kyle, I'm not sure I completely grasp the ramifications of your answer; I understand the thinking (I think) but the 80psi - will that flow nicely at the output of the Y junction or will it be a mess of inefficient turbulent water hitting the jet as some tries to back up the lower pressure pipe? I guess I'm asking if efficiency will take a major hit? Can I expect almost a double of potential power by doubling the pipes or will the pressure difference (backflow etc) cause a major hit for efficiency?

Thanks guys

Hey, I'm in a pretty unique position where I actually have two streams on my property which are suitable for microhydro. Who would have thought this could pose a problem!!?

On the North stream we have about 70m head and currently have a small turbine generating 400w. We'd like to add the West stream (about 60m head) to the turbine (which can handle it) but there is only one jet input on the turbine. Adding a second jet is not an option. So we though we would combine the two pipes to essentially double the flow from 2 to 4 litres/second.

The question is, if the pressures are different (about 10psi - that is 90psi North stream and 80psi West stream) will this mean the pressures will try to equalise with flow from from one pipe pushing against the other and causing efficiency loss? To what extent?