Hey Michael...we just installed a new Energy Systems low head hydro here in Victoria in case you are in the area ever and want to see it in action...loving it!
Jeffe On 11/2/04 6:38 PM, "Michael Lawley" <[EMAIL PROTECTED]> wrote: > > > Hi, > > To answer your questions. Below is data relayed to me by the client, I'm not > convinced about the accuracy of the data but here it is. > > Original unit was running at 131m on the gauge, 24- volt battery system. > The client has opened up the jet measuring the exhaust water and current flow > to the batteries. It seems a bit erratic to me so there is probably some > experimental error here. Our agent called in recently and advise that his > measurements were at best approximate, but is gives a general picture. > > Results below are for a worn bronze Pelton rotor > 2.5mm jet, 0.25 L/s, 1.5 amps, 36 Watts, 11% > 2.77mm jet, 0.3 L/s, 4 amps, 96 Watts, 25% > 3.0mm jet, 0.35 L/s, 7 amps, 210 Watts, 47% > 3.17mm jet, 0.40 L/s, 11 amps, 264 Watts, 52% > > The only result we got back for our turbine was with 5.1mm jet on the same > installation > delivering 30 amps at 24 volts. > > 5.1mm jet, 1 L/s, 30 amps, 720 Watts, 56% > > > We find that running a large rotor keeps the rpm down, the losses to air > friction and bearings are less at a lower rpm. We still run the Pelton rotor > at its optimum rpm and the Smart Drive magnetic rotor can be moved in and out > to alter the running speed until you achieve maximum output. > > I cannot agree that there is any rotor efficiency loss, if you run it at its > optimum speed (a little under half the theoretical jet velocity) the rotor > will maintain efficiency. > > Regards > > > > Michael Lawley > Renewable Energy Engineer > EcoInnovation > 671 Kent Road > R.D.1 > New Plymouth > New Zealand > > Phone: (NZ) 06 752 2765 > Web site: www.ecoinn.co.nz > email: [EMAIL PROTECTED] > > > ----- Original Message ----- > From: Max Klohn > To: [EMAIL PROTECTED] > Sent: Tuesday, November 02, 2004 2:32 AM > Subject: Re: [microhydro] Abrasion and surface hardness > > > > Hi Michael, > > a "large", low RPM rotor at such high head and low flow? what is the % > efficiency penality you get from that choice? > > I agree from my own experience that car alternators are quite > inefficient, so the smartdrive efficiency gain should compensate for the > rotor efficiency loss. Just for curiosity, how much power was your > client getting before and now? > . > Max > > El vie, 29 de 10 de 2004 a las 17:33, Michael Lawley escribi�: >> By way of example, we recently supplied a turbine on a site with a 135m of >> head, flow 0.5-1 L/s. >> >> The turbine the clients been using for the last 2 years had a bronze Pelton >> rotor made in the USA using a car alternator. The bronze rotor has been all >> but worn away after 2 years of continuous use. Also the car alternator needed >> the brushes replacing every 6 months and overhauling every 12 months. With a >> small PCD rotor it was running at about 2500 rpm. After 2 years of running >> the bronze rotor is very badly worn and unusable. >> >> We supplied this client a plastic Pelton rotor turbine on a trial basis to >> see what would happen. The rotor PCD is much larger as it is only running at >> 1000 rpm on a smart drive PMG. >> >> After 50 days on test the client has decided to purchase the turbine, he has >> indicated that some wear has occurred but is happy with the unit. After >> talking to the client most of the wear occurred when he was doing high flow >> tests. We has a 100mm line (way to large for the low flow he has most of the >> time). When he opened up the line with a larger jet accumulated grit/slit in >> the line started to move and sand blasted the rotor for may hours (the line >> is long and it took time to clean out). His view is that most of the wear >> occurred at this time as up to this point there was no noticeable wear on the >> spoons. >> >> We normally only approve them up to 100m of head. You can see from this >> example that 135m might be pushing it. Even if the spoons only last 6 months, >> 4 sets are still only a fraction of the price of the bronze unit. In fact he >> could buy over 10 sets of replacement spoons for the price of one bronze >> rotor. If you always have a spare set on hand then it is not a problem. It >> will not be long before we see Chinese injection moulded Pelton spoons that >> will make even our ones look expensive. >> >> Metal spoons have advantages but the labour component required to polish and >> balance them means that there are expensive to make in developed countries >> with high labour rates. Injection moulding on the other hand takes about 10 >> seconds a shot. >> >> For most clients in the 20-70m range (that we commonly supply) we have not >> had any reports of wear problem and we have enough of them out there to have >> heard of a problem if it existed. We wouldn't give a 2 year warrantee if we >> thought they wouldn't do the job. >> >> >> >> Regards >> >> >> >> Michael Lawley >> Renewable Energy Engineer >> EcoInnovation >> 671 Kent Road >> R.D.1 >> New Plymouth >> New Zealand >> >> Phone: (NZ) 06 752 2765 >> Web site: www.ecoinn.co.nz >> email: [EMAIL PROTECTED] >> >> >> ----- Original Message ----- >> From: Marc de Piolenc >> To: [EMAIL PROTECTED] >> Sent: Friday, October 29, 2004 1:52 PM >> Subject: [microhydro] Abrasion and surface hardness >> >> >> >> I'm a little disturbed at the assumption, evident in >> many recent messages, that a hard surface is >> necessarily more resistant to abrasion than a soft >> one. This is not correct, and people on this list in >> particular need to be aware of that. >> >> When a hard abrasive particle hits a hard surface, it >> loses nearly none of its kinetic energy, and in a >> turbulent stream may strike the surface again and >> again, each time spalling or scraping off a small >> amount of material. >> >> When it hits a soft surface, it tends to lose energy - >> essentially embedding itself temporarily. This can >> often result in LESS wear on a soft surface than on a >> hard one. The ultimate useful application of this >> property is in an industrial process called lapping, >> in which a soft tool (the lap) charged with an >> abrasive, is used to remove material from a much >> harder workpiece. >> >> It is therefore incorrect to assume that a plastic >> turbine bucket will necessarily have less wear in it >> than a metal bucket of the same profile. It MAY be so >> - not all soft surfaces have the property of resisting >> wear - but that must be substantiated by test. Surface >> hardness is only one of the relevant parameters. >> >> Best, >> Marc de Piolenc >> Iligan City, Philippines >> >> >> >> __________________________________ >> Do you Yahoo!? >> Yahoo! Mail Address AutoComplete - You start. We finish. >> http://promotions.yahoo.com/new_mail >> >> >> >> >> >> Does your company feature in the microhydro business directory at >> http://microhydropower.net/directory ? If not, please register free of charge >> and be exposed to the microhydro community world wide! >> >> NOTE: The advertisements in this email are added by Yahoogroups who >> provides us with free email group services. The microhydro-group does not >> endorse products or support the advertisements in any way. >> >> More information on micro hydropower at http://microhydropower.net >> >> To unsubscribe: send empty message to >> [EMAIL PROTECTED] >> >> >> Yahoo! Groups Sponsor >> ADVERTISEMENT >> >> >> >> >> >> ----------------------------------------------------------------------------->> - >> Yahoo! Groups Links >> >> a.. To visit your group on the web, go to: >> http://groups.yahoo.com/group/microhydro/ >> >> b.. To unsubscribe from this group, send an email to: >> [EMAIL PROTECTED] >> >> c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. >> >> >> >> >> [Non-text portions of this message have been removed] >> >> >> >> >> >> >> >> Does your company feature in the microhydro business directory at >> http://microhydropower.net/directory ? If not, please register free of charge >> and be exposed to the microhydro community world wide! >> >> NOTE: The advertisements in this email are added by Yahoogroups who provides >> us with free email group services. The microhydro-group does not endorse >> products or support the advertisements in any way. >> >> More information on micro hydropower at http://microhydropower.net >> >> To unsubscribe: send empty message to [EMAIL PROTECTED] >> Yahoo! Groups Links >> >> >> >> >> >> >> >> >> > > > > > > > Does your company feature in the microhydro business directory at > http://microhydropower.net/directory ? If not, please register free of charge > and be exposed to the microhydro community world wide! > > NOTE: The advertisements in this email are added by Yahoogroups who provides > us with free email group services. The microhydro-group does not endorse > products or support the advertisements in any way. > > More information on micro hydropower at http://microhydropower.net > > To unsubscribe: send empty message to [EMAIL PROTECTED] > > > Yahoo! Groups Sponsor > ADVERTISEMENT > > > > > > ------------------------------------------------------------------------------ > Yahoo! Groups Links > > a.. To visit your group on the web, go to: > http://groups.yahoo.com/group/microhydro/ > > b.. To unsubscribe from this group, send an email to: > [EMAIL PROTECTED] > > c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. > > > > > [Non-text portions of this message have been removed] > > > > > > > > Does your company feature in the microhydro business directory at > http://microhydropower.net/directory ? If not, please register free of charge > and be exposed to the microhydro community world wide! > > NOTE: The advertisements in this email are added by Yahoogroups who provides > us with free email group services. The microhydro-group does not endorse > products or support the advertisements in any way. > > More information on micro hydropower at http://microhydropower.net > > To unsubscribe: send empty message to [EMAIL PROTECTED] > Yahoo! Groups Links > > > > > > > ------------------------ Yahoo! Groups Sponsor --------------------~--> $9.95 domain names from Yahoo!. Register anything. http://us.click.yahoo.com/J8kdrA/y20IAA/yQLSAA/FGYolB/TM --------------------------------------------------------------------~-> Does your company feature in the microhydro business directory at http://microhydropower.net/directory ? If not, please register free of charge and be exposed to the microhydro community world wide! NOTE: The advertisements in this email are added by Yahoogroups who provides us with free email group services. The microhydro-group does not endorse products or support the advertisements in any way. More information on micro hydropower at http://microhydropower.net To unsubscribe: send empty message to [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/microhydro/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
