PRODUÇÃO E UTILIZAÇÃO DE GÁS
NATURAL: TRÊS PESQUISAS EM
DESENVOLVIMENTO NA POLI - USP
Silvio de Oliveira Júnior
Departamento de Engenharia Mecânica
ESCOLA POLITÉCNICA DA USP
[email protected]
Heat Transfer In A Twin-screw
Multiphase Pump: Thermal Modeling
And One Application In The
Petroleum Industry
Celso Yukio Nakashima
Silvio de Oliveira Jr.
Polytechnic School - University of São Paulo
Elisio F. Caetano
Petrobras/Cenpes
Objectives
• Modeling of heat transfer through screws
and casing
• Analyze thermal behavior during LOP
events
• Find temperature distributions in screws
and casing
• Seek for critical temperature values
during LOP
SMPS-500
Flow: 500 m3/h
Dp=60 bar
Speed: 0 – 3000 rpm
GVF = 0-95 %
Twin-Screw Pumps
chambers
discharge
suction
casing
peripheral clearance
radial clearance
flank clearance
Thermal Modeling
• Energy streams
Wk
Casing
Casing
Uk
Uk-1
Uk+1
Fluid
Screws
Uk
Rotor
r
Qkr

Qkc
Qenv
Thermal Modeling
• Energy and mass balances


dmk
 m ki  m ko
dt




dU k d ( mk u k )

 Qk  Wk  m ke  hke  mks  hks
dt
dt
• During LOP


dU k
 Q k  Wk
dt
dmk
0
dt
• Heat Transfer



Qk  Q kc  Q kr
Thermal Modeling
• Heat transfer through casing
y



Re
r
Ri

( - )
  max Re r 
( Re - R i )
x
Ri
Re
r
2
1 c cc T
 
T
T    T
T   T
 J
 
 J
  2

 J
 J
J kc t r 
r
    
r  z
Thermal Modeling
• Heat transfer through rotors
2
2
1   T    p    T

r
  1  
 
t r r  r    2r    2
r cr T
kr
Thermal Modeling
• Heat transfer coefficients
Rotor/fluid
Casing/fluid
Screw tip
Screw flank
Screw bottom
h (W/m2 .K)
3000.0
500.0
55.0
1250.0
Thermal Behavior During LOP
• Sample data during LOP
600
90
80
500
FLOW - M3/HR
400
60
50
300
40
200
30
20
100
10
0
15:02:53
0
15:04:19
15:05:46
15:07:12
TIME - HR:MIN:SEC
FLOW
CASING T
15:08:38
15:10:05
15:11:31
TEMPERATURE - °C
70
Thermal Behavior During LOP
• Results
(a) Screw temperature
before LOP
(b) Screw temperature
after LOP
(c) Casing temperature
after LOP
Conclusions
• Temperature rise was not critical;
• Prime recovery reduces temperatures;
• Next steps:
– Calculation of heat transfer coefficients
– Coupling of heat transfer model with the
thermo-hydraulic model of a twin-screw
multiphase pump
PERFORMANCE OPTIMIZATION OF
NATURAL GAS AND SUGARCANE BAGASSE
BASED COGENERATION SYSTEM
Leonardo Moneci Zamboni; Silvio de Oliveira Jr. and
Arlindo Tribess
Mechanical Engineering Department
Polytechnic School of the University of São Paulo - BRAZIL
Objective
This paper presents the exergy and
thermoeconomic performance
evaluation of cogeneration systems
designed for a sugar and alcohol mill
that uses natural gas and sugarcane
bagasse as fuels.
Cogeneration systems

The combined use of natural gas and
sugarcane bagasse in cogeneration
plants can generate electricity and
steam for processes as well as to allow
the commercialization of surpluses.
Cogeneration Systems
natural gas
2
3
8
System A
combus tion
chamber
4
2
gas turbine
compressor
air
7
9
1
heat recovery
steam generator 10
1
generation 1
5
cogeneration steam
8
12
18
10
H
node
generation 2
steam
turbine
20
13
19
19
process
23
11
stack
lost
steam
17
14
condens er
12
pump
23
27
17
node
14
16
13
15
20
pump
21
5
replacement
water
6
Cogeneration Systems
natural gas
2
3
8
System B
combustion
chamber
4
2
gas turbine
compressor
air
7
9
1
heat recovery
steam generator 10
1
generation 1
5
node
8
12
cogeneration steam
18
10
H
steam
turbine
steam
generator
9
air
21
16
18
17
generation 2
13
19
11
lost
steam
H
23
22
cane
bagasse
14
4
7
stack
22
condens er
12
20
26
pump
24
23
node
27
17
node
14
16
19
process
13
15
20
pump
21
5
replacement
water
6
Cogeneration Systems
natural gas
2
System C
combustion
chamber
3
8
4
2
gas turbine
compressor
air
7
9
1
heat recovery
steam generator 10
1
generation 1
5
node
8
12
H
23
21
11
15
18
F
17
generation 2
13
steam
generator
9
16
18
10
steam
turbine
air preheater
air
cogeneration steam
19
11
lost
steam
H
22
25
cane
bagasse
14
4
7
condens er
12
20
26
stack
22
24
23
node
pump
27
17
node
14
16
19
process
13
15
20
pump
21
5
replacement
water
6
Cogeneration Systems
natural gas
2
System D
combustion
chamber
3
8
4
2
gas turbine
compressor
1
air
generation 1
9
7
cane
bagasse
3
5
6
1
node
cogeneration steam
10
8
heat recovery
steam generator
12
18
10
H
generation 2
steam
turbine
13
19
11
17
lost
steam
20
23
stack
14
condens er
12
pump
23
27
17
node
14
16
19
process
13
15
20
pump
21
5
replacement
water
6
Cogeneration Systems
natural gas
2
3
8
System E
combustion
chamber
4
2
gas turbine
compressor
air
7
9
1
heat recovery
steam generator 10
1
generation 1
5
node
8
12
cogeneration steam
18
10
H
dryer
steam
turbine
steam
generator
6
3
9
16
17
11
23
cane
bagasse
18
generation 2
13
11
22
14
4
7
26
22
condens er
12
air
20
pump
24
23
node
27
17
node
14
16
19
lost
steam
H
15
stack
19
process
13
15
20
pump
21
5
replacement
water
6
Cogeneration Systems
natural gas
2
System F
combustion
chamber
3
8
4
2
gas turbine
compressor
air
generation 1
9
7
1
5
1
heat recovery
steam generator 10
cogeneration steam
8
12
18
10
H
steam
turbine
6
dryer
generation 2
13
19
23
11
20
17
lost
steam
7
3
stack
16
14
11
19
process
cane
bagasse
condens er
12
pump
23
27
17
node
14
16
13
15
20
pump
21
5
replacement
water
6
Cogeneration Systems
natural gas
2
3
8
System G
combustion
chamber
4
2
gas turbine
compressor
air
7
9
1
heat recovery
steam generator 10
1
generation 1
5
node
8
12
cogeneration steam
18
10
H
steam
turbine
steam
generator
9
air
21
16
18
17
generation 2
13
19
11
lost
steam
H
23
22
cane
bagasse
14
4
7
stack
22
pump
24
23
node
27
17
During 6 months
condens er
12
20
26
node
14
16
19
process
13
15
20
pump
21
5
replacement
water
6
Results
Specific average cost of eletricity [US$/MWh]
44
Sistema A
Sistema B
Sistema C
Sistema D
Sistema E
Sistema F
Sistema G
42
40
38
G
B
E
36
C
34
F
32
30
6
A
D
8
10
12
14
16
18
20
22
24
26
28
Sugar cane bagasse price [US$/t]
SISTEMA TETRA-COMBINADO DE TRIGERAÇÃO
AVALIAÇÃO TERMOECONÔMICA
Domingo Wilson Garagatti Arriola
Silvio de Oliveira Júnior
ESCOLA POLITÉCNICA DA USP
Sistema Tetra-Combinado de trigeração, para produção de eletricidade,
água gelada e vapor de processo
Parâmetros de desempenho do sistema
Tetra-Combinado de Trigeração
Ept
(kW)
15853
Qev
(kW)
3872
Qp
(kW)
4941

b
( %)
0,556 45,00
e
( %)
68,00
Custos de produção das utilidades geradas
ce
(US$/MWh)
cv
(US$/t)
cag
(US$/t)
36,37
19,23
0,13