Transcript Slide 1

Process Department
SSE-06
COMPARATIVE STUDY OF THE USE OF
VISUAL FLOW, INPLANT AND OTHER
SIMULATORS IN THE RELIEF SYSTEM
DESIGN
Prepared by: Pedro Ceballos
Revised by: Edgar Alfonso / Carmelo Trezza / María Pereira / Fernando Azuaje
Invensys User Group Series, Houston, October 15-16
Copyright © 2012. Inelectra SACA.- All rights reserved
Content
•
Relief Systems
•
Relief System Components
•
Relief System Hydraulic Evaluations
•
DA-1/ DA-2/ VDU Relief System Hydraulic Evaluation
•
Comparison of Simulators
•
Conclusions
Relief Systems
Definition:
•
Installing a pressure relief device, lines and means for transport and
disposal of the relief fluid in gaseous phase, liquid or both.
•
It is used when the presence of liquid, toxic properties or other factors
would make it dangerous to discharge into the atmosphere
Standards Applicable to Relief Systems:
API 520 I. Sizing, Selection, and Installation of Pressure-Relieving Devices in
Refineries. Part I—Sizing and Selection
API 520 II. Sizing, Selection, and Installation of Pressure-Relieving Devices in
Refineries. Part II—Installation
API 521. Pressure-relieving and Depressuring Systems
API 526. Flanged Steel Pressure Relief Valves
API 537. Flare Details for General Refinery and Petrochemical Service
API 576. Inspection of Pressure-relieving Devices
Relief System Components
Relief Valves
Flare
Discharge Lines
Protected
Equipments
Subheaders
Header
KnockOut Drum
KnockOut Drum Pumps
Relief System Hydraulic
Evaluations
P1= ? psig (Backpressure)
Criteria to define the
relief valve type:
P2= 0 psig
Relief Valve
(Set pressure) DPtip= 3 psig
BP(%) = Backpressure (psig)
SP
Set Pressure (psig)
Flare
Conventional:
BP/SP<10%
Balanced:
10%<BP/SP<30%
DPsello= 2 psig
Pilot:
30%<BP/SP<75%
KnockOut
Drum
DA-1/ DA-2/ VDU Relief System
Hydraulic Evaluation
Description:
Project: Deep Conversion
Location: Puerto La Cruz Refinery
Engineering: Detail
DA-1/DA-2 (Atmospheric
Units
Distillation Units)
Involved:
VDU (Vacio Unit)
Flare Type: Ground Flare
Darwin LNG; Australia
DA-1/ DA-2/ VDU Relief System
Hydraulic Evaluation
Main Objective:
* Validate the results obtained during the basic engineering of hydraulic
calculations associated with the main header of Ground Flare Relief System and
DA-1/DA-2/VDU referred to in the Deep Conversion Project of Puerto La Cruz.
Secondary Objective :
* Compare the use, advantages and disadvantages of simulators available in the
Company (INELECTRA) for Relief Systems Analysis (VISUAL FLOW, INPLANT,
Aspen Flare and Superchems).
DA-1/ DA-2/ VDU Relief System
Hydraulic Evaluation
Relief System Design :
Main Contingency: General Electric Power Failure
Total Relief Load: 782392 lb/h
Size Head: 42’’
DA-1: Atmospheric Tower
Equipment Involved DA-2: Atmospheric Tower
VDU: Vacuum Tower
Design Basis:
* Pressure of 10 psi at Ground Flare.
* In the General Electric Power Failure DA-1, DA-2 and VDU discharge
simultaneously.
* Maximum speed (Mach): Discharge Line: 0.75 / Header-SubHeader: 0.50.
* Backpressure criteria: Conventional: 10% / Balanced: 30% / Pilot: 75%.
DA-1/ DA-2/ VDU Relief System
Hydraulic Evaluation
Relief System Scheme:
VDU
TRAIN 1 & 2
42’’
Ground
Flare
DA-1
DA-2
DA-1/ DA-2/ VDU Relief System
Hydraulic Evaluation
VISUAL FLOW Simulation:
VDU Towers
DA-1 Tower
DA-2 Tower
DA-1/ DA-2/ VDU Relief System
Hydraulic Evaluation
INPLANT Simulation
VDU Towers
DA-1 Tower
DA-2 Tower
DA-1/ DA-2/ VDU Relief System
Hydraulic Evaluation
Aspen Flare Simulation
DA-2 Tower
DA-1 Tower
VDU Towers
DA-1/ DA-2/ VDU Relief System
Hydraulic Evaluation
SuperChems Simulation
DA-1/ DA-2/ VDU Relief System
Hydraulic Evaluation
Results. Cooling Water Failure (DA-1 Tower)
PSV-04416A PSV-04416B PSV-04416C PSV-04416D PSV-04416E PSV-04416F
SP=30psig SP=31.5psig SP=31.5psig SP=31.5psig SP=31.5psig SP=31.5psig
Outlet Line Mach Nro
0.191
0.191
0.191
0.191
0.191
0.191
BASIC ENG.
Backpressure (psig)
21.9
21.9
21.9
21.9
21.9
21.9
(SUPERCHEMS)
Back P / Set P (%)
73.1
69.6
69.6
69.6
69.6
69.6
Outlet Line Mach Nro
0.216
0.214
0.214
0.313
0.313
0.313
DETAIL ENG.
Backpressure (psig)
15.0
15.3
15.3
14.7
14.7
14.6
(VISUAL FLOW)
Back P / Set P (%)
49.9
48.6
48.6
46.6
46.6
46.5
SIMULATOR
PARAMETER
Results. General Power Failure (DA-2 Tower)
SIMULATOR
BASIC ENG.
(SUPERCHEMS)
DETAIL ENG.
(VISUAL FLOW)
PARAMETER
Outlet Line Mach Nro
Backpressure (psig)
Back P / Set P (%)
Outlet Line Mach Nro
Backpressure (psig)
Back P / Set P (%)
PSV-05391-A PSV-05391-B PSV-05391-C
SP= 30 psig SP= 31.5 psig SP= 31.5 psig
0.169
0.169
0.169
21.5
21.5
21.5
71.5
68.1
68.1
0.192
0.192
0.192
15.4
15.4
15.7
51.3
48.8
49.8
DA-1/ DA-2/ VDU Relief System
Hydraulic Evaluation
Origin of differences (Basic Eng. – Detail Eng.)
Header Inside Diameter 42’’:
Basic Eng.:
40’’
Fittings (Basic Eng.):
Elbow 90° 90 deg. 1 Weld. 90 deg angle
Elbow 45° 45 deg. Standard (R/D=1), all types
T branch Used as elbow. Standard, screwed
T run Run through tee. Screwed
Detail Eng. (Piping Classs)
41.188’’
K(12”)=1.247
Fittings (Detail Eng):
Elbow 90° Long-Radius (R/D=1.5), all types
Elbow 45° 45 deg. Long radius (R/D=1.5), all types
T branch Used as elbow. Standard, flanged/welded
T run Run through tee. Flanged/welded
K(12”)=0.217
DA-1/ DA-2/ VDU Relief System
Hydraulic Evaluation
Results. Cooling Water Failure (DA-1 Tower)
SIMULATOR
PARAMETER
Outlet Line Mach Nro
VISUAL FLOW Backpressure (psig)
Back P / Set P (%)
Outlet Line Mach Nro
INPLANT Backpressure (psig)
Back P / Set P (%)
Outlet Line Mach Nro
ASPEN FLARE Backpressure (psig)
Back P / Set P (%)
Outlet Line Mach Nro
SUPERCHEMS Backpressure (psig)
Back P / Set P (%)
PSV-04416A PSV-04416B PSV-04416C PSV-04416D PSV-04416E PSV-04416F
SP=30psig SP=31.5psig SP=31.5psig SP=31.5psig SP=31.5psig SP=31.5psig
0.216
0.214
0.214
0.313
0.313
0.313
15.0
15.3
15.3
14.7
14.7
14.6
49.9
48.6
48.6
46.6
46.6
46.5
0.209
0.209
0.209
0.209
0.209
0.209
15.9
15.9
15.9
15.9
15.9
15.9
52.8
50.3
50.3
50.3
50.3
50.3
0.209
0.212
0.211
0.210
0.210
0.210
16.3
15.9
16.1
16.1
16.1
16.1
54.4
50.4
51.0
51.2
51.3
51.1
0.210
0.210
0.210
0.210
0.210
0.210
15.0
15.0
15.0
15.0
15.0
15.0
50.1
47.7
47.7
47.7
47.7
47.7
DA-1/ DA-2/ VDU Relief System
Hydraulic Evaluation
Results. General Power Failure (DA-2 Tower)
SIMULATOR
VISUAL FLOW
INPLANT
ASPEN FLARE
SUPERCHEMS
PARAMETER
Outlet Line Mach Nro
Backpressure (psig)
Back P / Set P (%)
Outlet Line Mach Nro
Backpressure (psig)
Back P / Set P (%)
Outlet Line Mach Nro
Backpressure (psig)
Back P / Set P (%)
Outlet Line Mach Nro
Backpressure (psig)
Back P / Set P (%)
PSV-05391-A
SP= 30 psig
0.192
15.4
51.3
0.185
16.2
54.1
0.185
16.3
54.3
0.187
15.8
52.6
PSV-05391-B
SP= 31.5 psig
0.192
15.4
48.8
0.185
16.1
51.0
0.185
16.3
51.9
0.187
15.8
50.1
PSV-05391-C
SP= 31.5 psig
0.192
15.7
49.8
0.185
16.1
51.0
0.186
16.3
51.7
0.187
15.8
50.1
Comparision of Simulators
Mounting the Model:
Allows change the method of thermodynamic
Allows added viscosity experimental data.
Easy to add components and uses them when
performing the simulation on other computers
Allows to create pseudocomponentes with PM>1000
VISUAL
ASPEN
INPLANT
FLOW
FLARE
YES
YES
YES
NO
YES
NO
SUPERCHEMS
NO
NO
NO
YES
YES
NO
NO
YES
NO
YES
Allowsto add over 50 pseudocomponentes in a line
YES
NO
YES
YES
Allows to add pipes to the library
Allows to copy valves and equipments
Allows to enable and disable lines and equipments
Ease of data entry
YES
YES
NO
YES
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
Comparision of Simulators
Simulator Flexibility:
VISUAL
ASPEN
INPLANT
SUPERCHEMS
FLOW
FLARE
Evaluation of the pressure drop at the entrance of
the safety valve
Can simulate various scenarios (contingencies)
with a single run
Sizing Relief Valves
Sizing Relief Headers
Allows isometric drawings
Dynamic Evaluation of Fire Contingency
Radiation Evaluation
It takes into account energy losses to the
environment
YES
NO
NO
YES
YES
NO
YES
NO
YES
YES
YES
NO
NO
YES
YES
NO
NO
NO
YES
YES
NO
NO
NO
YES
YES
NO
YES
YES
NO
NO
YES
YES
Comparision of Simulators
Results Report:
Getting quick results (duration of the run)
Reports the pressure drop in each segment / fitting
Calculation of relief temperature
Easy to calculate backpressure on PSV
VISUAL
ASPEN
INPLANT
SUPERCHEMS
FLOW
FLARE
YES
YES
YES
NO
YES
YES
NO
YES
YES
NO
NO
NO
YES
YES
YES
NO
Comparision of Simulators
General recommendations for use of simulators
according to the case study
Case
Simulator
VISUALFLOW
Simulation of gas relief
Superchems
Simulation of viscous liquid relief
Inplant
Simultaneous evaluation of several cases where contingency is VISUALFLOW
involved one relief valve
Aspen Flare
Quick estimate of the backpressure
INPLANT
VISUALFLOW
Evaluation of the pressure drop at the entrance to the relief valve
Superchems
Evaluation of Fire event when multiple loads are involved (dynamic
Superchems
simulation)
Superchems,
Evaluation of heat loss to the environment
AspenFlare
Conclusions
* The diameters established for the main header (42"), for
DA-1 subheader (42") and DA-2 subheader (30") during
basic engineering are according with the design basis.
* It should verify that the fittings on the pipes do not create
an excessive pressure drop avoid unnecessary
overdesigns.
* According to the system under study, each relief systems
simulator offers particular advantages, among them are
the INPLANT by the facilities in the model assembly and
VISUAL FLOW for flexibility and good results.
Thanks for your
attention!!