Q = 200 m 3 / h = ( 200 / 3600 ) m 3 / s = 0.0556 m 3 / s Q=200m^3/h=(200/3600)m^3/s=0.0556m^3/s Q=200m3/h=(200/3600)m3/s=0.0556m3/s

泵进口直径也叫泵吸入口直径，是指泵吸入法兰处管的内径。可用下式计算。 D s = K s Q n 3 = ( 4 ∼ 5 ) 200 / 3600 2900 3 = 107.0 ∼ 133.8 m m D_s=K_s\sqrt[3]{\frac{Q}{n}}=(4\sim5)\sqrt[3]{\frac{200/3600}{2900}}=107.0\sim133.8mm Ds​=Ks​3nQ​ ​=(4∼5)32900200/3600​ ​=107.0∼133.8mm其中 K s = 4 ∼ 5 K_s=4\sim5 Ks​=4∼5，取 D s = 125 m m D_s=125mm Ds​=125mm，该直径应从标准法兰中选取。

泵出口直径也叫泵排出口径，是指泵排出口法兰处管道内径。一般用下式计算。 D d = K d Q n 3 = ( 3.5 ∼ 4.5 ) 200 / 3600 2900 3 = 93.7 ∼ 120.4 m m D_d=K_d\sqrt[3]{\frac{Q}{n}}=(3.5\sim4.5)\sqrt[3]{\frac{200/3600}{2900}}=93.7\sim120.4mm Dd​=Kd​3nQ​ ​=(3.5∼4.5)32900200/3600​ ​=93.7∼120.4mm其中 K d = 3.5 ∼ 4.5 K_d=3.5\sim4.5 Kd​=3.5∼4.5，取 D d = 100 m m D_d=100mm Dd​=100mm，该直径应从标准法兰中选取。

v s = 4 Q D s 2 π = 4 × 200 / 3600 0.12 5 2 × π = 4.5271 m / s v_s=\frac{4Q}{D_s^2\pi}=\frac{4\times200/3600}{0.125^2\times\pi}=4.5271m/s vs​=Ds2​π4Q​=0.1252×π4×200/3600​=4.5271m/s

v d = 4 Q D d 2 π = 4 × 200 / 3600 0.10 0 2 × π = 7.0736 m / s v_d=\frac{4Q}{D_d^2\pi}=\frac{4\times200/3600}{0.100^2\times\pi}=7.0736m/s vd​=Dd2​π4Q​=0.1002×π4×200/3600​=7.0736m/s

h g = p a ρ g − h c − p v ρ g − N P S H a = 10.33 − 0.5 − 0.24 − 7.5 = 2.09 m h_g=\frac{p_a}{\rho g}-h_c-\frac{p_v}{\rho g}-NPSH_a=10.33-0.5-0.24-7.5=2.09m hg​=ρgpa​​−hc​−ρgpv​​−NPSHa​=10.33−0.5−0.24−7.5=2.09m取 h c = 0.5 m h_c=0.5m hc​=0.5m，装置汽蚀余量 N P S H a NPSH_a NPSHa​假设为 7.5 m 7.5m 7.5m

N P S H r = N P S H a / 1.3 = 7.5 / 1.3 = 5.77 m NPSH_r=NPSH_a/1.3=7.5/1.3=5.77m NPSHr​=NPSHa​/1.3=7.5/1.3=5.77m

C = 5.62 n Q N P S H r 3 / 4 = 5.62 × 2900 × 200 / 3600 5.7 7 3 / 4 = 1032 C=\frac{5.62n\sqrt{Q}}{NPSH_r^{3/4}}=\frac{5.62\times2900\times\sqrt{200/3600}}{5.77^{3/4}}=1032 C=NPSHr3/4​5.62nQ ​​=5.773/45.62×2900×200/3600 ​​=1032

n s = 3.65 n Q H 3 / 4 = 3.65 × 2900 × 200 / 3600 8 4 3 / 4 = 89.9177 ≈ 90 n_s=\frac{3.65n\sqrt{Q}}{H^{3/4}}=\frac{3.65\times{2900}\times\sqrt{200/3600}}{84^{3/4}}=89.9177\approx90 ns​=H3/43.65nQ ​​=84