- -

.

.

.

.

.

- 2 -

, , , , km , ..

, , , , km , .

- () (1-1) 3 .

pd - ps vd2 - vs2 Havail = + + y (1-1) 2g

pd vd ps, vs , y (1-1) . 3 , m.

- () . /sec, /min, /sec, gpm, cfs .

- () (;kg-m/kg) . .Q H Pw .

Pw = HQ (1-2)

Pw (water power) , kg-m/sec , 75kg-m/sec(HP) . , . (P) , KS .

p(%) = Pw/P = HQ/P (1-3)

(1.1) .

(1.1) ) ,

, , , .

- 3 -

(turbo) , (impeller) () .

- (centrifugal type) , (spiral or volute type) diffuser casing .

- () .

- (axial flow type) .

-

- , , (samlping

pump) (), , , ,

- ,

() () . 6m, 100m 200m .

1. () bucket . (2.1) , , . , .

(2.1)

- (2.2) , , . .

(2.2)

2. (Torricelli ) (2.3) 1m 760mm

- 4 -

, 0.101MPa. [0.101MPa=1.033kgf/, 13.6 760mm, 10.33m ] 760mm . 0 .

760mm

a

b

b

a

(2.3) Torricelli

, 8m 6m.

3. () . , , . . () . . . (2.1) .

(2.1) (1 )()

()

()

()

05

10

0.028850.025470.02268

152030

0.020500.018710.1607

4. 100 1

. 100 . , . (2.2), (2.3) . .

(2.2) () (m)

0 10 20 30 90100

0.0623 0.1251 0.2383 0.4326 7.149310.3323

(2.3) (m) (m)

0 100 200 300 5003,000

10.3310.2110.09 9.97 9.73 7.15

5. (2.4) 1 2 , , .

1

2

V1

V2

A1

p1r1

z1 z2

A2

p2r2

2.4)

v12 p1 v22 p2 -- + -- + z1 = -- + -- + z2 = const (2-1) 2g 2g

v,p,z, , , , . v2/2g , p/

- 5 -

, z . [ / = kgfm/kgf = m]

v2/2g (velocity head), p/ (pressure head), z (potential head) , v2/2g (dynamic pressure), p (static pressure) , (total pressure) . (2-1) (Bernoulli's equation) . 1 2 , 1 2 1 2 , (2-2) .

v12 p1 v22 p2 -- + -- + z1 = -- + -- + z2 + H (2-2) 2g 2g

H 1 2 .

6. . (2.5) 1 2 1 2 .

(2.5)

Hth , H (2-3) .

v12 p1 v22 p2 -- + -- + z1 + Hth = -- + -- + z2 + H (2-3) 2g 2g

Hth H H Hth = H+H (2-4)

.

v12 p1 v22 p2 -- + -- + z1 + H = -- + -- + z2 2g 2g p2 v22 p1 v12 H = (-- + -- + z2) - (-- + -- + z1) (2-4) 2g 2g H , kgfm/kgf=m (2-5) . (kgfm/kgf)(kgf/) = kgf/ .

v12 v22 -- + p1 + z1 + H = -- + p2 + z2 (2-5) 2g 2g

1. - , KS . (3.1) , , , , , . , , . 25/m 47m , 225kw, 86% , 40m 29.2/m, 230kw, 83% .

(3.1) 500400

- 6 -

, . 0 () 0 , . , , , . . ( = )

- (, , ) .

, , (), ( ), , ,

, , , , , , , .

, , , , .

(3.1)

N(rpm)

Q(/min)H(m)

Pw(kw)

P(kw)

(%)

12345....

. .

. ,

.

. () (6-0.05)

.

2. (Ns) , , . 3 2 Ns .

Ns = N [Q]1/2 / H3/4 (3-1)

, 1/2 , 1 .

Q=14/min, H=100m, N=1750rpm 1 Ns = 1750 [14]1/2 / [100]3/4 = 207 2 Ns = 1750 [14]1/2 / [50]3/4 = 348 1 Ns = 1750 [7]1/2 / [100]3/4 = 147 Ns Ns , Ns . Ns Ns . , .

3. Ns . Ns -

- 7 -

, 0 () . (3.2a), - Ns , Ns . (3.2b), - Ns , Ns .(3.2c)

(3.2)

4. , 2 , .

Q' N' D' --- = --- [---]3 (3-2) Q N D H' N' D' --- = [---]2 [---]2 (3-3) H N D

P' N' D' p --- = [---]3 [---]5 [---] (3-4) P N D p'

, P : , N : , D : , p : .

- , 20% .

1 (3-2,3,4) D'/D=1, p'/p=1 (3-5) . Q' = Q [N'/N] H' = H [N'/N]2 P' = P [N'/N]3 (3-5)

, Q,H,P Q',H',P' 1, 2, 3 .

- , . , . Ns . .

5. - (cavitation) 100 1 100 , . , . , , , . , , . . , .

- 8 -

- (NPSH ; Net Positive Suction Head) (NPSHav) (NPSHre) .

- (NPSHav) system NPSH .

NPSHav

NPSHav = hsv = ps/ - pv/ hs - fvs2/2g (3-6)

hsv : (m) ps : (kgf/ abs.) pv : (kgf/ abs.) : (kgf/) hs : () (m) [ (-), (+)] fvs2/2g : (m)

(3-6) NPSHav hs , .

NPSHav

0 (3-6) .

NPSHav hsv = 10 - hs - fvs2/2g (3-7)

(3.3)

NPSH ( )

(3.2) NPSH

4m

3m

ps : (kgf/abs) 1.0330 10

4 1.0330 104

pv : (kgf/abs) 0.0238 10

4 0.0238 104

: (kgf/) 998.2 998.2

hs : (m) - 4 + 3

fvs2/2g : (m) 0.7 0.5

hsv = ps/ - pv/ hs - fvs2/2g

hsv = 10.35-0.24-4-0.7 = 5.41m

hsv = 10.35-0.24+3-0.5 = 12.61m

[ 20, 0m ]

- (NPSHre) (NPSHre) . (3.4) NPSHre a-c' , Thoma .

(3.4)

NPSHre(Hsv) , Hsv Q,n (3-8) .

S = Q1/2/Hsv3/4 N (3-8)

, Q

- 9 -

1/2 . Q /min, Hsv m, N rpm S Ns 12001300 .

NPSHre ( Thoma ) H, Hsv Thoma() .

= Hsv / H = NPSHre / H (3-9)

, H . , . .

- [NPSHre(1+)] [NPSHav NPSHre(1+)] , 0.3( 1m) . NPSHre NPSHav . (3.4) 2 NPSH A , A , .

NPSHre .

(3.5) NPSHav NPSHre

( ) - ,

, NPSHav .

- NPSHav 1.3 NPSHre . -

. -

.

- .

- .

- .