an integrated analytical process gc and shs based on is can communication circor tech patrick lowery...
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An Integrated Analytical Process GC and SHS Based on IS CAN Communication
Circor Tech
Patrick Lowery
ABB Analytical
Tracy Dye
IFPAC 2008
Baltimore
Vision
An integrated process analytical system that receives, sends and acts on critical multivariate data to monitor, communicate and control its status and health via any networked client.
NeSSITM Value Proposition
Improved System Reliability and Serviceability
Reduced Capital Costs
Reduced Operational and Maintenance Costs
Innovative, Early Adopter Market
? Time
Prevalence
Gen 2
Gen
1
Achieving the stated vision and value proposition in an innovative, early adopter market dictates the need for a phased, risk reduced approach.
Phased Market Approach
Phase 1 – Connectivity Hybrid communication system
Discrete analog outputs for single signal devices
Discrete digital inputs
IS CAN networked components for multivariate data devices
Basic control Temperature, flow, filtration backup, valve switching
Basic indication Sample flow, ΔP, temperature
Phased Market Approach
Phase 2 – “Self Describing” All SHS components have open standard
description file (EDDL, XML, etc.)
Real time operational view of SHS on any networked client
Fully integrated process analytical system
IS CAN for the NeSSITM Communication Bus
“Plug and play” in Div 1/Zone 1 classified areas
CAN is everywhere in demanding applications (marine, auto, aerospace)
Balanced signaling (differential drive) enables superior noise rejection (relative to unbalanced single end) especially over cables
Open and Standard, already built in … Data Integrity Mechanisms
Integral Bus Error Recovery and Self Correction
Message Prioritization Via Non-Destructive Arbitration
Mature and Well Defined Application Layers Such As CANopen
Master to slave or peer to peer communication This allows individual devices to contain their own alarms and setpoints
Allow for the system to interact with other devices in the system without the “SAM”
Smart SHS Topography
What is needed to ascertain status of SHS? Power
Pressures
Flows
Temperature (both ambient and actual fluid temp)
System valve status
Filter “health” (need two signals, either pressure/flow, or pressure & differential pressure)
Example of basic smart sample system topography
Smart SHS Topography
FIBER OPTIC CAN CABLE
(ENTIRE GC CONTROL ON FIBER OPTIC CANopen NETWORK
ANALOG I/O & IS BARRIERS, IF NEEDED
SAMIS POWER
SAMPLE SYSTEM
CABINETHEATER INTRINSICALLY
SAFE CANbus
ANALYZER LOWER LEVEL NETWORK
PROCESS CONTROL NETWORK
DCS SYSTEM AND FIREWALL/ NETWORK SWITCHING STATION
Smart SHS Topography
BYPASS FAST LOOP FLOW, TEMP, PRESSURES
FILTER HEALTH
(FLOW AND DIFF PRESSURE)
VALVE STATUS
FLOW TO ANALYZER
GC ATM REFERENCE PRESSURE
DIFF PRESSURE AND FLOW ACROSS STREAM SELECT
POWER MONITOR AND DEVICE INVENTORY/ HEALTH FROM CAN TO SAM
WHAT IS “SAM” There is no industry consortium on the definition of SAM (Sensor
Actuator Manager)
The definition of SAM in this system topology is: Bridge between C1D1 (Zone 1) and C1D2 (Zone 2) for CAN
communications
Integrated analog I/O to digitize 4-20mA devices
Obtains inventory of all CAN networked devices using IEEE virtual TEDs concept (i.e. device profiles/ data sheets)
Monitors total IS can bus power consumption and health
Has a basic application interface that can pass alarm triggers and set points down to devices and pass alarms and data up to GC
GC is not the sample system master per se, but a data server
Future upgrade path for CAN device metadata to provide system configuration data up to HMI at GC interface
Comparison to Traditional/ Legacy SHS Purely mechanical SHS
Lower initial capital cost, but no data from system
If system goes down, analyzer goes down, process is diverted or fines can occur (in emission monitoring applications)
EPA requires backfill of worst case data for emission monitoring analyzer downtime, average of $15-25k per event
Higher cost in human “capital” and higher average analyzer down time
One refining case study found an average of 6 hours of process down time (per event) from time of DCS alarm to time that analyzer/ process chemistry was verified
6 hours of process downtime = BIG $$$
Comparison to Traditional/ Legacy SHS Analog instrumented SHS (GEN 1.5)
Analog devices (in most but not all cases) are less expensive
No multi-variate data from single device
All devices must be discreetly wired and must have
Discreet IS barrier
Analog I/O module to PLC or data logger
PLC or data logger
Ethernet or other field bus communications module
Data can be shown that digital bus implementation can reduce overall system cost
~$300 per sensing point cost savings on pressure/temp sensing
~$2000 per sensing point on flow, including cabling/wiring cost
~20-30% reduction in needed modular or fitting hardware
~40% reduction in wiring/ installation / integration cost
Still challenges ahead Although major technical hurdles are being addressed,
there are still some market challenges ahead
Further reduction of cabling cost needed along with some more choices of chemical compatibility options
New types of power levels and digital bus implementation at IS certifying bodies
More IS power supply vendors needed
Further reduction in component costs can be realized by economy of scale (although highly expensive gen 1.5 systems have been economically justified at several large refineries)
Still opportunities ahead GEN 2, digital bus SHS also provide new opportunities
Integration of “grab bag” closed-loop sample system with continuous GC SHS for validation
Can differentiate between analyzer problem and SHS problem; if analyzer isolated as problem, can automatically route sample to sample cylinder for lab analysis
Can localize heating solutions with tighter control or vaporize liquid samples near source to GC, remove the need for problematic liquid inject valves
XML metadata into device profiles for graphical representation on HMI displays
Integration of continuous analyzers along with associated SHS onto analyzer network