Types of hydro turbine

Types of hydro turbine

Present-day hydro turbines come in a variety of shapes (Figure 17). They also vary considerably in size, with ‘runner’ diameters ranging from as little as a third of a metre to some 20 times this. Here we look at how they work, the factors that determine their efficiency, and the site parameters that determine the most suitable turbine.

Gidroturbin turlari

Zamonaviy turbinalar har xil shaklga ega (17-rasm). Ularning o'lchamlari ham sezilarli darajada farq qiladi: "slayder" ning diametri metrning uchdan biridan taxminan 20 martagacha. Bu erda biz ularning qanday ishlashini, samaradorligini belgilovchi omillarni va eng maqbul turbinani aniqlaydigan sayt parametrlarini ko'rib chiqamiz.

Figure 17 Types of turbine runner. Shakl 17 Turbinali yuguruvchining turlari

Francis turbines (figure 17, top left) are by far the most common type in present-day medium- or large-scale plants, being used in locations where the head may be as low as 2 m or as high as 200 m. They are radial-flow turbines, which means the water flow is inwards towards the centre, and modern turbines can achieve efficiencies as high as 95% – but only under optimum conditions, as maintaining exactly the right speed and direction of the incoming water relative to the runner blades is important.

Frensis turbinalari (17-rasm, yuqori chap) zamonaviy o'rta va yirik o'simliklarning eng keng tarqalgan turi bo'lib, ular boshi 2 m dan 200 m gacha bo'lishi mumkin bo'lgan joylarda qo'llaniladi, ular radial oqim turbinalari, ya'ni suv oqimi ichkariga qarab markazga yo'naltiriladi va zamonaviy turbinalar 95% gacha samaradorlikka erishishi mumkin, ammo faqat optimal sharoitda yuguruvchining pichog'iga nisbatan keladigan suv tezligi va yo'nalishini aniq saqlab turish muhimdir.

‘Propeller’ or axial-flow turbines (figure 17 top centre) sweep their blades through the entire area which the water enters, and are therefore suitable for very large volume flows and have become usual where the head is only a few metres. In such turbines the efficiency can be improved by varying the angle of the blades when the power demand changes.

"Pervanel" yoki eksenel turbinalar (17-rasm, eng yuqori markaz) suvning pichoqlari bilan butun maydonni qoplaydi va shuning uchun juda yuqori hajmli oqimlarga mos keladi va boshlari atigi bir necha metr bo'lgan joyda odatiy holga aylandi. Bunday turbinalarda samaradorlikni pichoqlar balandligini o'zgartirish orqali yaxshilash mumkin, chunki quvvatga talab o'zgaradi.

 Kaplan turbines (figure 17 bottom centre) are axial turbines where the blade angle may be varied to improve efficiency.

Kaplan turbinalari (17-rasm, pastki markaz) - eksenel turbinalar, bu erda samaradorlikni oshirish uchun pichoq burchagi o'zgarishi mumkin.

Pelton Wheels (figure 17 bottom left) are the preferred turbine for sites of the type shown in Figure 5.14 (c) with heads above 250 metres or so. The pelton is in contrast to the reaction turbines discussed above, it is an impulse turbine, operating in air at normal atmospheric pressure, and is basically a wheel with a set of double cups or ‘buckets’ mounted around the rim. The water passes round the curved bowls, and under optimum conditions gives up almost all its kinetic energy. The power can be varied by adjusting the jet size to change the volume flow rate, or by deflecting the entire jet away from the wheel.

Pelton g'ildiraklari (17-rasm, pastki chap) - shakllari 5.14 (c) da ko'rsatilgan 250 metrdan yuqori boshli turbinalar. Pelton, yuqorida tavsiflangan reaksiya turbinalaridan farqli o'laroq, normal atmosfera bosimida havoda ishlaydigan impuls turbinasidir va asosan, chekka atrofida o'rnatilgan ikkita stakan yoki "belkurak" to'plami bo'lgan g'ildirakdir. Suv egri kosalardan oqib o'tadi va optimal sharoitlarda deyarli barcha kinetik energiyani yo'qotadi. Quvvatni oqim hajmini o'zgartirish uchun reaktiv hajmini sozlash yoki butun reaktivni g'ildirakdan chetga surib o'zgartirish mumkin.

Turgo turbines (figure 17 top right) are a variant on the Pelton wheel, where the double cups are replaced by single, shallower ones, with the water entering on one side and leaving on the other. This is still an impulse turbine, but is able to handle a larger volume of water than a Pelton wheel of the same diameter gives it an advantage for power generation at medium heads.

Turgo turbinalari (17-rasm, yuqori o'ng) - bu Pelton g'ildiragidagi o'zgarish, bu erda er-xotin stakan kichikroq, bitta stakan bilan almashtiriladi, suv bir tomondan kirib, boshqa tomondan chiqadi. U hanuzgacha impuls turbinasidir, ammo u xuddi shu diametrdagi Pelton g'ildiragiga qaraganda katta hajmdagi suv bilan ishlay oladi, bu esa unga elektr energiyasini o'rta boshlarda ishlab chiqarish afzalligini beradi.

The cross-flow turbine (figure 17 bottom right) is another impulse type. The water enters as a flat sheet rather than a round jet. It is guided on to the blades, travels across the turbine and meets the blades a second time as it leaves.

O'zaro faoliyat oqim turbinasi (17-rasm pastki o'ngda) yana bir turtki hisoblanadi. Suv dumaloq oqim emas, balki tekis choyshab sifatida kiradi. U pichoqlar tomon burilib, turbinadan o'tadi va chiqib ketayotganda pichoqlarni ikkinchi marta uchratadi.