1.1 jet pump structure.
Jet pump structural parameters include area ratio m, throat l2, throat length l4, roar pipe import angle α1 and diffusion angle α2 five factors. Where m = F2 / F1 = (d2 / d1) 2
By describing the performance of the liquid jet pump and the following three parameters to express:
Flow ratio q = Qb / Qa
The head ratio h = [(HcZc + Vc2 / 2g) - (Hb + Zb + Vb2 / 2g)] / [(Ha + Za + Va2 / 2g) - (Hb + Zb + Vb2 / 2g)]
Efficiency value η = qh / (1-h)
1.2 jet pump structure parameters of its performance
According to a large number of domestic and foreign scholars, when the range of values ​​is: m = 2-9, l2 = 1-6d0, l4 = 4-9d2, α1 = 150-1200, α2 = 0-140, v0 <50m / s When the result of its performance.
From this it can be seen that each structural parameter has the following effect on its performance:
(1) The area ratio is the main parameter affecting the jet pump, m = 3-4 is the high efficiency area.
(2) throat distance l2 = 1.0d0, the jet pump has a high efficiency point.
(3) Diffusion angle also has a greater impact on jet pump performance, when 40 <α2 <100 for the jet pump high-efficiency zone.
(4) The inlet angle of the throat has less effect on its performance.
(5) The length of the throat has a great influence on its efficiency, and its effective area is 6d4 <14 <8d2.
Because the experimental results with the boundary conditions selected range of different values ​​vary, so the various factors on the performance of the jet pump ability to change.