PIV 에 의한 상수도 배관용 틸팅디스크 체크 밸브의 손실저감에 관한 연구

A PIV Study on Loss Reduction for Tilting Disk Check Valve Installed in Piping System of Water Supply

발표자 : 이 중 열

한국수자원공사 수도시설처

Research Purpose Research Purpose

▶ ▶ 가압펌프장에 설치된 틸팅 디스크 체크밸브의 손상사고에 대한 유 가압펌프장에 설치된 틸팅 디스크 체크밸브의 손상사고에 대한 유 체역학적인 원인규명이 부족함체역학적인 원인규명이 부족함▶ ▶ 밸브 손상사고의 원인 규명을 위한 밸브 손상사고의 원인 규명을 위한 11 차적인 유동특성파악차적인 유동특성파악

▶ ▶ 손실 수두 저감 방안제시손실 수두 저감 방안제시

▶ ▶ 유동장의 특성과 상관관계를 갖는 압력강하 메커니즘에 관한 실험유동장의 특성과 상관관계를 갖는 압력강하 메커니즘에 관한 실험 적 고찰적 고찰

Photos of Tilting Disc Check ValvePhotos of Tilting Disc Check Valve

Front viewFront view Rear viewRear view

Preliminary ExperimentationPreliminary Experimentation

고해상도 고속도 카메라를 이용한 고해상도 고속도 카메라를 이용한 11 차 예비 실험수행차 예비 실험수행

밸브 내부 유동특성을 파악한 후 손실수두 저감 방안모색밸브 내부 유동특성을 파악한 후 손실수두 저감 방안모색

유체역학적 접근을 통한 손실수두 발생원인 조사 유체역학적 접근을 통한 손실수두 발생원인 조사

Item Specification

Visualization

equipments

High speed CCD camera 1280 X 1024 Pixels

Light source Ar-Ion laser (5W)

Sheet light Cylindrical lens

Measuring

conditions

Working fluid Tap water

Temp. 15 ℃

Tracer particles PVC (100 μm)

Image

processing

Host PC Pentium 4 (1.7GHz)

Calculation time 30 sec./frame

IdentificationCross correlation

Cactus 3.1

Error rate Less 1.2 %

Experimental Conditions IExperimental Conditions I

Visualization photo of middle section (45 deg open)Visualization photo of middle section (45 deg open)

Visualization photo of side section (45 deg open) Visualization photo of side section (45 deg open)

Visualization ResultsVisualization Results

4545oo 열린 밸브중앙단면의 가시화결과열린 밸브중앙단면의 가시화결과 , , 비교적 균일한 흐름의 비교적 균일한 흐름의 유동장을 형성하고 있음을 확인유동장을 형성하고 있음을 확인

Visualization ResultsVisualization Results

4545oo 열린 밸브 보스단면 가시화결과열린 밸브 보스단면 가시화결과 , , 상당히 불규칙적인 유동장이 상당히 불규칙적인 유동장이 형성되고 있음을 확인형성되고 있음을 확인

밸브 보스단면의 돌출형상에 의한 영향으로 유동방향으로 교란발생밸브 보스단면의 돌출형상에 의한 영향으로 유동방향으로 교란발생 압력 회복률 지연압력 회복률 지연

보스단면의 형상을 유선형에 가깝게 변형 보스단면의 형상을 유선형에 가깝게 변형 유동장의 안정화 기대 유동장의 안정화 기대 밸브 후방 압력회복률의 상승 기대 밸브 후방 압력회복률의 상승 기대 밸브 수두손실 감소 밸브 수두손실 감소

Photos of Experimental ApparatusPhotos of Experimental Apparatus

Definition of Measurement PositionDefinition of Measurement Position

60

60

Mid section

Side sectionPressure hole

1 3 4 5 62

Arrangement of PIV SystemArrangement of PIV System

Laser

Monitor Hi-8mm & VTR

Host Computer Printer

Water Tank

Pump

DigitalFlow Meter

High Speed CameraDigital

Manometer

Power Supply

Model Valve

Disk Drive

Photos of Experimental ApparatusPhotos of Experimental Apparatus

Pressure hole Pressure hole

Pressure hole Pressure hole

Pre-improved modelPre-improved model

Improved modelImproved model

Item Specification

Visualization

equipments

Camera 1008 X 1018 Pixels

Light source Nd-Yag dual pulsed laser

Sheet light Cylindrical lens

Measuring

conditions

Working fluid Tap water

Temp. 15 ℃

Tracer particles PVC (100 μm)

Image

processing

Host PC Pentium 4 (1.7GHz)

Calculation time 30 sec./frame

IdentificationCross correlation

Cactus 3.1

Error rate Less 1.0 %

Experimental Conditions IIExperimental Conditions II

Pressure MeasurementPressure Measurement

밸브 전밸브 전 · · 후방으로 모두 후방으로 모두 77 개의 등간격 개의 등간격 (60mm) (60mm) 압력 공 설치압력 공 설치

유량 유량 : 30 liter/sec (: 30 liter/sec ( 밸브 완전개방시밸브 완전개방시 ))

밸브개도 변화 밸브개도 변화 : Full open, 15 deg, 30 deg, 45 deg, 60 deg : Full open, 15 deg, 30 deg, 45 deg, 60 deg

(( 관경 관경 : 0.05m, : 0.05m, 유량 유량 : 30m: 30m33/hr, /hr, 동점성계수 동점성계수 : 1.1565 X 10: 1.1565 X 10-6 -6 mm22/sec)/sec)

Re = 183,311 Re = 183,311

Visualization results by PIV (Mid-section)Visualization results by PIV (Mid-section)

x- Axis(mm)

y-A

xis(

mm

)U=3.0(m/sec)

0.2

396

8.5

917

5.8

077

0 80 1610

25

50

x- Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.12

958.

6591

5.81

59

0 99 1970

27

53

00

5050

161161

Unit : mmUnit : mm

00

5050

161161

Unit : mmUnit : mm

Improvement Model – Instantaneous Velocity Fields (Full-Open) Improvement Model – Instantaneous Velocity Fields (Full-Open)

Pre-Improvement Model – Instantaneous Velocity Fields (Full-Open) Pre-Improvement Model – Instantaneous Velocity Fields (Full-Open)

161161

Visualization results by PIV (Mid-Section)

00

5050Unit : mmUnit : mm

Pre-Improvement Model – Averaged Velocity Fields (Full-Open) Pre-Improvement Model – Averaged Velocity Fields (Full-Open)

x- Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.03

188.

8113

5.88

48

0 99 1970

27

53

00

5050

161161

Unit : mmUnit : mm

Improvement Model – Averaged Velocity Fields (Full-Open) Improvement Model – Averaged Velocity Fields (Full-Open)

x- Axis(mm)

y-A

xis(

mm

)U=3.0(m/sec)

0.3

175

7.9

632

5.4

146

0 80 1610

25

50

Visualization results by PIV (Mid-Section)

x-Axis(mm)

y-A

xis(

mm

)U=3.0(m/sec)

0.23

968.

5917

5.80

77

0 80 1610

25

50

x-Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.12

958.

6591

5.81

59

0 99 1970

27

53

00

5050Unit : mmUnit : mm

Pre-Improvement Model – Instantaneous Velocity Profile (Full-Open) Pre-Improvement Model – Instantaneous Velocity Profile (Full-Open)

00

5050

161161

Unit : mmUnit : mm

Improvement Model – Instantaneous Velocity Profile (Full-Open) Improvement Model – Instantaneous Velocity Profile (Full-Open)

161161

Visualization results by PIV (Mid-Section)

x-Axis(mm)

y-A

xis(

mm

)U=3.0(m/sec)

0.31

757.

9632

5.41

46

0 80 1610

25

50

x-Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.03

188.

8113

5.88

48

0 99 1970

27

53

00

5050Unit : mmUnit : mm

Pre-Improvement Model – Averaged Velocity Profile (Full-Open) Pre-Improvement Model – Averaged Velocity Profile (Full-Open)

00

5050

161161

Unit : mmUnit : mm

Improvement Model – Averaged Velocity Profile (Full-Open) Improvement Model – Averaged Velocity Profile (Full-Open)

161161

Visualization results by PIV (Side-Section)

x- Axis(mm)

y-A

xis(

mm

)U=3.0(m/sec)

0.0

288

9.9

906

6.6

700

0 108 2170

34

68

x- Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.12

769.

8077

6.58

10

0 107 2150

28

57

00

5050

161161

Unit : mmUnit : mm

00

5050

161161

Unit : mmUnit : mm

Improvement Model – Instantaneous Velocity Fields (Full-Open) Improvement Model – Instantaneous Velocity Fields (Full-Open)

Pre-Improvement Model – Instantaneous Velocity Fields (Full-Open) Pre-Improvement Model – Instantaneous Velocity Fields (Full-Open)

x- Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.1

237

10.1

985

6.8

403

0 108 2170

34

68

x- Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.11

549.

8280

6.59

05

0 107 2150

28

57

00

5050Unit : mmUnit : mm

Pre-Improvement Model – Averaged Velocity Fields (Full-Open) Pre-Improvement Model – Averaged Velocity Fields (Full-Open)

00

5050

161161

Unit : mmUnit : mm

Improvement Model – Averaged Velocity Fields (Full-Open) Improvement Model – Averaged Velocity Fields (Full-Open)

161161

Visualization results by PIV (Side-Section)

Visualization results by PIV (Side-Section)

x-Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.02

889.

9906

6.67

00

0 108 2170

34

68

x-Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.12

769.

8077

6.58

10

0 107 2150

28

57

00

5050Unit : mmUnit : mm

Pre-Improvement Model – Instantaneous Velocity Profile (Full-Open) Pre-Improvement Model – Instantaneous Velocity Profile (Full-Open)

00

5050

161161

Unit : mmUnit : mm

Improvement Model – Instantaneous Velocity Profile (Full-Open) Improvement Model – Instantaneous Velocity Profile (Full-Open)

161161

Visualization results by PIV (Side-Section)

161161

x-Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.12

3710

.198

56.

8403

0 108 2170

34

68

x-Axis(mm)

y-Ax

is(m

m)

U=3.0(m/sec)

0.11

549.

8280

6.59

05

0 107 2150

28

57

00

5050Unit : mmUnit : mm

Pre-Improvement Model – Averaged Velocity Profile (Full-Open) Pre-Improvement Model – Averaged Velocity Profile (Full-Open)

00

5050

161161

Unit : mmUnit : mm

Improvement Model – Averaged Velocity Profile (Full-Open) Improvement Model – Averaged Velocity Profile (Full-Open)

Visualization results by PIV (Mid-Section)

x- Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.01

8711

.865

67.

9166

0 87 1740

27

53

x- Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.17

3313

.775

59.

2415

0 103 2060

28

56

00

5050

161161

Unit : mmUnit : mm

00

5050

161161

Unit : mmUnit : mm

Improvement Model – Instantaneous Velocity Fields (30 deg) Improvement Model – Instantaneous Velocity Fields (30 deg)

Pre-Improvement Model – Instantaneous Velocity Fields (30 deg) Pre-Improvement Model – Instantaneous Velocity Fields (30 deg)

Visualization results by PIV (Mid-Section)

x- Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.4

238

10.9

711

7.4

553

0 87 1740

27

53

x- Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

1.01

6712

.939

18.

9650

0 103 2060

28

56

00

5050Unit : mmUnit : mm

Pre-Improvement Model – Averaged Velocity Fields (30 deg) Pre-Improvement Model – Averaged Velocity Fields (30 deg)

00

5050

161161

Unit : mmUnit : mm

Improvement Model – Averaged Velocity Fields (30 deg) Improvement Model – Averaged Velocity Fields (30 deg)

161161

Visualization results by PIV (Mid-Section)

x-Axis(mm)

y-A

xis(

mm

)U=3.0(m/sec)

0.01

8711

.865

67.

9166

0 87 1740

27

53

x-Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.83

9713

.328

09.

1653

0 103 2060

28

56

00

5050Unit : mmUnit : mm

Pre-Improvement Model – Instantaneous Velocity Profile (30 deg) Pre-Improvement Model – Instantaneous Velocity Profile (30 deg)

00

5050

161161

Unit : mmUnit : mm

Improvement Model – Instantaneous Velocity Profile (30 deg) Improvement Model – Instantaneous Velocity Profile (30 deg)

161161

Visualization results by PIV (Mid-Section)

x-Axis(mm)

y-A

xis(

mm

)U=3.0(m/sec)

0.42

3810

.971

17.

4553

0 87 1740

27

53

x-Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

1.01

6712

.939

18.

9650

0 103 2060

28

56

00

5050Unit : mmUnit : mm

Pre-Improvement Model – Averaged Velocity Profile (30 deg) Pre-Improvement Model – Averaged Velocity Profile (30 deg)

00

5050

161161

Unit : mmUnit : mm

Improvement Model – Averaged Velocity Profile (30 deg) Improvement Model – Averaged Velocity Profile (30 deg)

161161

Visualization results by PIV (Side-Section)

x- Axis(mm)

y-A

xis(

mm

)U=3.0(m/sec)

0.0

533

12.7

086

8.4

901

0 93 1860

29

58

x- Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.06

7312

.845

48.

5861

0 107 2150

28

57

00

5050

161161

Unit : mmUnit : mm

00

5050

161161

Unit : mmUnit : mm

Improvement Model – Instantaneous Velocity Fields (30 deg) Improvement Model – Instantaneous Velocity Fields (30 deg)

Pre-Improvement Model – Instantaneous Velocity Fields (30 deg) Pre-Improvement Model – Instantaneous Velocity Fields (30 deg)

Visualization results by PIV (Side-Section)

x- Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.1

298

11.9

788

8.0

291

0 93 1860

29

58

x- Axis(mm)

y-A

xis(

mm

)

U=3.0(m/sec)

0.03

3013

.049

68.

7107

0 107 2150

28

57

00

5050Unit : mmUnit : mm

Pre-Improvement Model – Averaged Velocity Fields (30 deg) Pre-Improvement Model – Averaged Velocity Fields (30 deg)

00

5050

161161

Unit : mmUnit : mm

Improvement Model – Averaged Velocity Fields (30 deg) Improvement Model – Averaged Velocity Fields (30 deg)

161161

Visualization results by PIV (Side-Section)

x-Axis(mm)

y-A

xis(

mm

)U=3.0(m/sec)

0.05

3312

.708

68.

4901

0 93 1860

29

58

x-Axis(mm)

y-Ax

is(m

m)

U=3.0(m/sec)

0.05

1113

.503

29.

0191

0 107 2150

28

57

00

5050Unit : mmUnit : mm

Pre-Improvement Model – Instantaneous Velocity Profile (30 deg) Pre-Improvement Model – Instantaneous Velocity Profile (30 deg)

00

5050

161161

Unit : mmUnit : mm

Improvement Model – Instantaneous Velocity Profile (30 deg) Improvement Model – Instantaneous Velocity Profile (30 deg)

161161

Visualization results by PIV (Side-Section)

x-Axis(mm)

y-A

xis(

mm

)U=3.0(m/sec)

0.12

9811

.978

88.

0291

0 93 1860

29

58

x-Axis(mm)

y-Ax

is(m

m)

U=3.0(m/sec)

0.03

3013

.049

68.

7107

0 107 2150

28

57

00

5050Unit : mmUnit : mm

Pre-Improvement Model – Averaged Velocity Profile (30 deg) Pre-Improvement Model – Averaged Velocity Profile (30 deg)

00

5050

161161

Unit : mmUnit : mm

Improvement Model – Averaged Velocity Profile (30 deg) Improvement Model – Averaged Velocity Profile (30 deg)

161161

Results ( Full open )

(Full open)압력강하그래프

28

25 25 25 25 25

36

28.530

31.5 31.533

0

5

10

15

20

25

30

35

40

1 2 3 4 5 6

(m

mH

g)

밸브

전후

압력

차 Full open( )개선후Full open( )개선전

Results ( 15 deg )

(15deg)압력강하그래프

59.5

48 48 48 47 46

83

59 60 62 64 64

0

10

20

30

40

50

60

70

80

90

1 2 3 4 5 6

(m

mH

g)

밸브

전후

압력

차 15deg( )개선후15deg( )개선전

Results ( 30 deg )

(30deg)압력강하그래프

121115 113 112 110.5 110.5

170

135.5 139.5 139.5 139.5 139.5

0

20

40

60

80

100

120

140

160

180

1 2 3 4 5 6

(m

mH

g)

밸브

전후

압력

차 30deg( )개선후30deg( )개선전

Results ( 45 deg )

(45deg)압력강하그래프

280

245 241 238 238 237.5

334

277 281 280 280 280

0

50

100

150

200

250

300

350

400

1 2 3 4 5 6

(m

mH

g)

밸브

전후

압력

차 45deg( )개선후45deg( )개선전

Results ( 60 deg )

(60deg)압력강하율그래프

462

416 414.5 414.5 414 414

500.5

453 456 457 457 457

0

100

200

300

400

500

600

1 2 3 4 5 6

(m

mH

g)

밸브

전후

압력

차 60deg( )개선후60deg( )개선전

속도장의 분포에서 형상개선 후의 후류의 크기감소 효과를 알 수있속도장의 분포에서 형상개선 후의 후류의 크기감소 효과를 알 수있으며으며 , , 보스부 형상변형에 따른 영향으로 후류 억제의 효과를 얻음보스부 형상변형에 따른 영향으로 후류 억제의 효과를 얻음

Conclusion

속도프로파일 분포에서 형상개선 후의 시간평균 속도프로파일 분포에서 형상개선 후의 시간평균 v v 방향 속도성분이 방향 속도성분이 개선전에 비해 낮은 값을 가지므로 밸브에 의한 유동교란의 감소개선전에 비해 낮은 값을 가지므로 밸브에 의한 유동교란의 감소 , , 방출후류의 감쇄방출후류의 감쇄 , , 이에따른 손실저감 효과를 얻음이에따른 손실저감 효과를 얻음

압력측정 결과압력측정 결과 , , 밸브가 완전열림 상태인경우 밸브 직후에서 밸브가 완전열림 상태인경우 밸브 직후에서 22%, 22%, 22 번 위치에서 번 위치에서 12.2%, 12.2%, 대부분의 압력이 회복되었다고 판단되는 대부분의 압력이 회복되었다고 판단되는 66번 번 위치에서 위치에서 24.2%24.2% 의 손실감소 효과를 얻을 수 있음의 손실감소 효과를 얻을 수 있음본 연구에서 제안한 밸브시트 형상개선의 효과는 우수한 성과를 본 연구에서 제안한 밸브시트 형상개선의 효과는 우수한 성과를 제시함을 알수 있고제시함을 알수 있고 , , 추후 실제 모델을 제작하여 손실 저감 효과를 추후 실제 모델을 제작하여 손실 저감 효과를 검증할 필요성이 있음검증할 필요성이 있음

Pre-Improvement Model – Averaged Velocity Profile (30 deg, Front Side) Pre-Improvement Model – Averaged Velocity Profile (30 deg, Front Side)

Improvement Model – Averaged Velocity Profile (30 deg, Front Side) Improvement Model – Averaged Velocity Profile (30 deg, Front Side)

Animation results by PIV (Mid-Section)Animation results by PIV (Mid-Section)

Animation results by PIV (Side-Section)Animation results by PIV (Side-Section)

Pre-Improvement Model – Averaged Velocity Profile (30 deg, Front Side) Pre-Improvement Model – Averaged Velocity Profile (30 deg, Front Side)

Improvement Model – Averaged Velocity Profile (30 deg, Front Side) Improvement Model – Averaged Velocity Profile (30 deg, Front Side)