Transient Acceleration in Belt Conveyor Speed Control

Vermelding onderdeel organisatie

July 2016 Darwin 1

Transient Acceleration

in Belt Conveyor Speed Control

Yusong Pang, Daijie He & Gabriel Lodewijks

Transport Engineering and Logistics

Delft University of Technology

Introduction

•  Belt conveyor speed control

•  Control dynamics and scenarios

•  Determination of acceleration

•  Fuzzy speed control system

•  Implementation

3

5

Energy Savings of Speed Control

Tens of mil

lions kWh’s

saving

Thousands of

_{tons CO}

Speed Control in Transient Operations

Belt speed regulation in

transient operation

7

Operational Risks

•  Belt over-tension

•  Belt slippage

•  Motor over-heating

•  Acceleration/control profile

•  Discontinuous control vs. discrete control

•  Stress cycles

Material Loading Scenarios

Scenario 1: constant loading degree in

long term operations

Scenario 2: moderately varying loading

degree in between long term operations

Scenario 3: moderately varying loading

degree in between short term operations

Scenario 4: excessively varying loading

degree in all operations

9

Material Loading Practice

Scenario 1

Data from dry bulk terminal operations (EMO)

Scenario 2

Scenario 3

Determination of Acceleration

Estimation

(

)

(

)

2

2

S

S

m g

a

Cfg

S

L m

m

m

⎛

⎞

₋

⎜

⎟

=

+

⎜

ʹ

+

ʹ

+

ʹ

⎟

⎝

⎠

(

)

(

)

1

2

2

roll belt bulk

e

m g

a

Cfg

L m

m

m

−

=

−

ʹ

+

ʹ

+

ʹ

(

)

(

)

2

2

rf sf nom motor d roll belt bulk heat

d roll belt bulk rotor gear

i i T

R CfgL m

m

m

a

R L m

m

m

m

m

ʹ

ʹ

ʹ

−

+

+

=

ʹ

ʹ

ʹ

ʹ

ʹ

⎡

+

+

+

+

⎤

⎣

⎦

(

)

max

min

max,

tension

,

max,

slip

,

max,

heat

a

₌

a

a

a

2

V

T

a

π

Δ

=

11

Determination of Acceleration

Optimization

Five element model

1

2

3

4

i

i-1

i-2

i+2

i+3

i+4

N-3

N-2

N-1

_N

i+1

Mass

K

H

V

C

G

F

_F

_±

_dF

Determination of Acceleration

13

Fuzzy Speed Control

%

(

)

%

actual nominal

Actual Loading Rate

v

v

Reference Loading Rate

Fuzzy Speed Control

%

(

)

%

actual nominal

Actual Loading Rate

v

v

Reference Loading Rate

=

⋅

_

1

i act

i

nom

15

Implementation

Parameters (symbol, unit) value Parameters (symbol, unit) value Conveyor length (Lconv, m) 1000 Friction coefficient between drive pulley

and conveyor belt (µ, -) 0.35 Nominal capacity (Cdes, t/h) 2500 Wrap angle of belt on drive pulley (α, o) 180 Nominal speed (Vb, m/s) 5.2 Motor torque rating (Tnom,motor, Nm) 1592 Belt width (B, m) 1.200 Motor service factor (isf, -) 1.15 Young’s modulus of belt (Eb, N/m2) 340*106 Reduction factor of gearbox (irf, -) 18 Cross section area of belt (Abelt, m2) 0.01236 Inertia of gearbox reduced to a mass on the

drive pulley radius (m’gearbox, kg)

37

Nominal rupture force of belt per unit width (kN, kN/m)

500 Inertia of motor reduced to a mass on the drive pulley radius (m’motor, kg)

6654

Mass of belt per unit length (m’belt, kg/m) 14.28 Minimal safety factor in steady state operation (SB,min,-)

8.0

Mass of idler per unit length on the carrying side (m’roll,c, kg/m)

14.87 Minimal safety factor in transient operation (SA,min,-)

5.4

Mass of idler per unit length on the return side (m’roll,r, kg/m)

7.72 Coefficient of secondary resistances (C, -) 1.09

Mass of gravity take-up device (mT, kg) 5060 Artificial friction coefficient (f, -) 0.018

17

19

Conclusions

•  Transient speed control taking operational risks into

account

•  Acceleration determination based on theoretical estimation

and simulation optimization

•  Applicability of speed control taking material loading

scenarios into account

•  Energy savings balanced with stress cycles in fuzzy speed

regulations

21

THANK YOU VERY MUCH

!