© Siemens AG 2015
Process Gas Chromatographs
SITRANS CV
■ Overview
■ Design
Enclosure
• EEx-d version standard
• Heating adjustable from 60 to 165 °C (isothermal)
• Decentralized installation close to sampling point
Analytical modules
The compact analytical modules contain all the functional
components of a chromatograph. The SITRANS CV operates
with:
• Live injection
• Valveless live switching on microchip basis
• Standardized analytical modules
• Multidetection through use of up to 8 micro thermal
conductivity detectors in smallest possible areas
(e.g. on all column/purging outputs and injection)
The SITRANS CV gas chromatograph (GC), which is based on
the innovative analytical technology of the MicroSAM, is an
analyzer that has been specially developed for natural gas
analysis. The device concept enables the higher and lower
calorific value, standard density and Wobbe index (according to
ISO, AGA 8, Gost standard) to be determined in a way that is not
only cost-effective, but also quick, precise and reliable.
■ Benefits
Flexible installation: The rugged and compact design enables
installation in even extreme areas of application, such as
offshore exploration, or directly at the pipeline. The SITRANS CV
has the certification required (such as explosion protection or
splashwater protection) to meet the requirements of these applications.
Like the MicroSAM, the SITRANS CV consists of a basic unit and
an analysis module, which, if necessary, can be replaced in as
short a time as possible. Combined with low power and gas
consumption, this keeps operating costs down.
Notable features of the CVControl software, which has been
specially developed for calibration-related applications,
includes its ease of operation and transparency.
The automatic method optimization integrated in the software
increases the repeatability of the calorific value measurement
and reduces the cost of ownership.
■ Function
Live injection
The SITRANS CV has a two-stage injection system. Using a
micro injection valve, a defined quantity of sample is first brought
up to the carrier gas pressure. This eliminates the pressuredependent error in the dosing quantity present with conventional
systems. In the second stage, the sample is transferred to the
column by a valveless micro injection system (live dosing).
The result is an "active" injection.
The injection volume can be varied time-controlled, and exactly
matched to the column requirements.
Valveless live column switching
Because of the high dead volume of conventional valves, only
the valveless version can be considered for a miniaturized
system. In this case, the generation of differences in flow using
several electronic pressure regulators at appropriate positions of
the column setup causes a change in the flow directions.
(The system operates according to the Wheatstone principle,
but pneumatically.) The functions "Cut" and "Backflushing" can
then be implemented free of dead volume.
The column system
The serial RS 485/RS 232 and Ethernet interfaces enable
communication with both the control system and a flow
computer.
The separation system consists of up to three separation
columns connected in series. Micro TCDs or micro live circuits
are installed in sequence ("inline") upstream and downstream of
the individual columns. Three electronic pressure regulators
supply the columns with carrier gas and carry out the switching
functions (injection, backflushing and cut).
Like the MicroSAM, the unit’s high analytical capability can be
attributed to narrow-bore capillary columns, live injection, live
switching and in-line detection.
By using narrow-bore capillary columns, the separation at high
resolution is carried out within a much shorter time, approx.
factor 2 to 3 compared to standard capillary columns.
■ Application
• Analysis of natural gas in power plants:
- For quality control
- For turbine optimization
- Pipeline monitoring
• Analysis of natural gas when opening up sea beds
(off-shore plants).
• Analysis of bio-natural gas in preprocessing plants
• Analysis of natural gas in liquefaction and regasification plants
(LNG Regasification and Storage)
• Determination of calorific value in natural gas for power plants,
in gas transfer stations, or during turbine optimization
• Analysis of calorific value in natural gas preparation plants
Electronic pressure regulators
A high pressure stability together with rapid changing rates in
the hPa range are required for precise and fast switching. This is
achieved in the electronic pressure regulators by means of a
piezo actuator.
Detector
The micro TCDs (silicon wafer technology) work on the principle
of continuous measurement of the different thermal conductivities of the carrier gas and the components to be measured.
The measurement can be carried out without falsification by
avoiding catalytic effects on the heating wires and maintaining a
constant flow velocity. This permits consistent in-line detection,
i.e. without qualitative or quantitative losses of substances.
Siemens AP 01 · 2015
3/27
3
© Siemens AG 2015
Process Gas Chromatographs
SITRANS CV
Modules
The standardized application modules generally feature live
injection and live switching functions, detectors and separation
columns.
Column 1
Detector
Column 2
Detector
Circuit
Column 3
Detector
C09
Detector
Sil5
TCD
Sil5
TCD
Live
Porabond Q
TCD
Injection
Non-polar aromatic and
aliphatic hydrocarbons
TCD
C01
Sil5
Injection
TCD
TCD
RTX-1
Injection
All components except
molecular filter components
PoraPLOT/Porabond Q TCD
Live
CO2, C2, H2O
C3, C4, C5, C6+
C13
3
Non-polar aromatic
and aliphatic hydrocarbons
TCD
C3, i-C4, n-C4, neo-C5,
i-C5, n-C5
Sum C6+ as sum peak
in the backflush
HayeSepN
Molecular filter
TCD
H2, (Ar+O2), N2, C1,
CO
TCD
Live
N2, CH4, CO2, C2
Application
Component
Possible working range (%)
The SITRANS CV is a storage product. Precalibration is carried
out at the factory, using helium and argon (as the carrier gas)
and a calibration gas. The measured components and switching
functions (live injection, backflushing, cut) are saved in the GC.
The calibration process itself should be performed during
commissioning on-site.
Oxygen
0 ... 4
Measurements can be made within the following working
ranges:
Table 2: Measuring range of the additional measured component oxygen
of the extended calorific value analysis (see Article No. 7KQ3105-1)
The remark in footnote 1 about the detection of oxygen and
nitrogen is not valid in the case of an extended calorific value
analysis. In this case, all components from the Table 1
"Measured components and performance parameters for Pos.
8_0 (master setup, standard calorific value analysis in accordance with ISO 6976-1995)" plus oxygen are detected and
quantified.
Component
Checked working range Possible working range
(%)
(%)
Methane
57 ... 100
50 ... 100
Nitrogen1)
0 ... 22
0 ... 25
For the analysis of biomethane the following components and
their working ranges are measured (Table 3).
Carbon dioxide
0 ... 12
0 ... 20
Component
Ethane
0 ... 14
0 ... 20
Possible working range Calibration gas for bio(%)
methane measurement
(%)
Propane
0 ... 5
0 ... 15
Methane
> 80
89
i-butane
0 ... 0.9
0 ... 10
Nitrogen
<8
4
n-butane
0 ... 1.8
0 ... 10
Ethane
<6
2.5
Neopentane
0 ... 0.1
0 ... 1
Carbon dioxide
<4
2.5
i-pentane
0 ... 0.12
0 ... 1
Propane
<5
1.0
n-pentane
0 ... 0.12
0 ... 1
Hexane+2)
Butane
< 1.2
0.2
0 ... 0.08
0 ... 3
Oxygen
<3
0.2
< 0.7
0.2
<3
0.2
Hexane
0 ... 1
Heptane+3)
0 ... 1
2-Methylpropane
(isobutane)
Octane
0 ... 1
Hydrogen
Nonane+4)
0 ... 1
Table 3: Measured components, working ranges and calibration gas for
the analysis of biomethane
Helium
Concentration can be entered as a fixed value in
the components list
H2S
< 500 ppm
No measured component
High/low calorific value
Calculated
Calculated
Density and relative
density
Calculated
Calculated
Wobbe index
Calculated
Calculated
Compressibility factor
Calculated
Calculated
Normalisation factor
Calculated
Calculated
Table 1: Measured components and performance parameters for
Pos. 8_0 (master setup, standard calorific value analysis in accordance
with ISO 6976-1995)
1)
Any oxygen or carbon monoxide present in the sample will be detected
along with the nitrogen and, therefore, taken into account when the
nitrogen concentration is determined.
2)
Hexane+ = group(iso/n-hexane to iso/n-nonane)
3)
Heptane+ = group(iso/n-hexane) and group(iso/n-heptane to iso/n-nonane)
4)
Nonane+ = group(iso/n-hexane), group(iso/n-heptane), group(iso/n-octane),
group(iso/n-nonane)
3/28
Siemens AP 01 · 2015
© Siemens AG 2015
Process Gas Chromatographs
SITRANS CV
For analysis of natural gas with backflush summation, the
following components and working ranges are measured:
Component
Possible working range (%)
Methane
50 ... 100
Nitrogen
0 ... 25
Carbon dioxide
0 ... 20
Ethane
0 ... 20
Propane
0 ... 15
Measurements within the scope of the possible working ranges
(Table 1 "Measured components and performance parameters
for Pos. 8_0 (Master setup, standard analysis of calorific value in
accordance with ISO 6976-1995)", right column, and Table 2
"Measuring range of the additional measured component
oxygen of the extended analysis of calorific value (see Article
No. 7KQ3105-1)") are possible. However, checking of the
repeatability and correctness has not been carried out by the
official German body "Physikalisch technischer Bundesanstalt
(PTB)".
i-butane
0 ... 10
Concentration range (mol.%)
n-butane
0 ... 10
Repeatability according to ISO
6974-5 (2001); Mol fraction (%),
absolute
50 < xi < 100
0.03 ... 0.035
1 < xi < 50
0.011 ... 0.03
0.1 < xi < 1
0.006 ... 0.011
xi < 0.1
< 0.006
Neopentane*
i-pentane
0 ... 1
n-pentane
0 ... 1
Hexane+
0 ... 3
Helium
Concentration can be entered as a
fixed value in the component list
H2S
No measured component
High/low calorific value
Calculated
Density and relative density
Calculated
Wobbe index
Calculated
Compressibility factor
Calculated
Normalization factor
Calculated
Table 4: Component and measuring ranges for the analysis, including
backflush summation
* Because the neopentane concentration is very small in practice, this
component is not calibrated and is measured with the relative response
factor of isopentane. For this reason, a possible working range is not
indicated.
Analyses within the checked working range as well as the quality
parameters resulting from these (upper and lower calorific
values, density and relative density, Wobbe index, compression
and normalization factors) correspond to the requirements listed
below.
Table 5: The repeatability of the measured components complies with
ISO 6974-5 (2001) – Annex B (Article No. 7KQ3105-0, 7KQ3105-1)
The repeatability of the calorific value and standard density
achieve a relative standard deviation of < 0.01 %. SITRANS CV
for the analysis of biomethane achieves a relative standard
deviation of < 0.05 %.
The calibration gas is an extremely important factor for consideration in terms of the MPE (maximum permissible error), and
has a significant effect on the accuracy of the overall measuring
system. For this reason, SITRANS CV - based on a comparative
measuring procedure - can never be more accurate than the
calibration gas used. Other parameters besides the accuracy
data on the calibration gas certificate are important for the
accuracy of a system. Examples of these include the optimum
gas composition, the ambient temperatures of the calibration
gas cylinders during transportation and operation, potential
condensation of, for instance, higher hydrocarbons in a
calibration gas cylinder, and the functionality of the sample
preparation system.
Under optimum conditions, the SITRANS CV achieves an MPE of
< 0.1 % for the calorific value and the standard density, whereby
the system for measuring biomethane produces an MPE of
< 0.5 %.
SITRANS CV is designed for measuring with various configurations; the calibration gases required for this purpose are shown
below. (Table 6, Measurement and calibration gas components):
Siemens AP 01 · 2015
3/29
3
© Siemens AG 2015
Process Gas Chromatographs
SITRANS CV
SITRANS CV – Overview of possible configurations and the required calibration gases
Carrier gas
He
He
Ar
He
Analyzer module
C09
C01
C01
C13
Calorific value analysis Calorific value analysis Basic Bio-CH4
C6+
C6+ with oxygen
Extended calorific
C6+ backflush
value analysis Bio-CH4
Calculation standard is ISO 6976, GOST and AGA 8 can be selected
3
Article No.
7KQ 3105-0
7KQ 3105-2
7KQ 3105-3
Hydrogen
-
-
-
M CR
-
Oxygen
-
M CR
M CR
M CR
-
Nitrogen
M CR
M CR
M CR
M CR
M CR
Carbon dioxide
M CR
M CR
M CR
M CR
M CR
Methane
M CR
M CR
M CR
M CR
M CR
Ethane
M CR
M CR
-
M CR
M CR
Propane
M CR
M CR
-
M CR
M CR
Isobutane
M CR
M CR
-
M CR
M CR
Butane
M CR
M CR
-
M CR
M CR
Neopentane
M*1
M*1
-
-
M*1
Isopentane
M CR
M CR
-
-
M CR
M CR
Pentane
Group C6+
7KQ 3105-1
M CR
M CR
-
-
M*2 CR
M*2 CR
-
-
-
-
-
-
-
M*2 CR
Group C6+ backflush
Extended application 7KQ 3105- B02
Separate measurement of Group C6 and
Group C7+
M*3 CR*3
M*3 CR*3
-
-
-
Separate Groups C6,
C7, C8, C9
M*4 CR*4
M*4 CR*4
-
-
-
Caution!
Use of the SITRANS CV with a carrier gas different to that of the supplied solution can lead to faults and to the destruction
of the analysis module. Depending on the composition of the calibration gas, external heating for the calibration gas cylinder may be necessary.
M
Measured
CR
Required as calibration component; composition see catalog AP 01 – SITRANS CV - Function
M*1
Neopentane is measured with the response factor of isopentane;
for direct calibration of neopentane: see operating instructions
M*2
Group C6+ is measured with the relative response factor of n-hexane
M*3/CR*3
Groups C6 and C7+ are measured separately and calibrated with n-hexane and n-heptane, respectively
M*4/CR*4
Group C6, Group C7, Group C8, Group C9 are measured and calibrated separately
Table 6: Overview of device versions and available measurement configurations and the calibration gas compositions required for them
3/30
Siemens AP 01 · 2015
© Siemens AG 2015
Process Gas Chromatographs
SITRANS CV
■ Technical specifications
Climatic conditions
Permissible ambient temperature
-20 ... +55 °C (depending on oven
temperature)
Permissible storage/transport
temperature
-30 ... +70 °C
Permissible relative humidity
Max. 90 %
Protection against dust and moisture
• According to EN 60529/IEC 60529
• According to NEMA 250
IP 65
NEMA 4X
Power supply
SITRANS CV with SIMATIC Extension Unit
Power supply
24 V DC (18.5 ... 30.2 V)
External fuse
T2.5 A
Power consumption, typical
18 W
Power consumption, maximum
60 W
3
Dimensions and weights
Width x depth x height
360 x 300 x 220 mm
(approx. 14" x 12" x 9")
Weight
15 kg (35 lb.)
Mounting
Installation on
Post, pipe or wall
Distance from wall or next chromatograph
300 mm (12")
Distance from ceiling or floor
200 mm (8")
Electromagnetic compatibility
Noise suppression
According to CISPR 11 / EN 55011 /
DIN VDE 0875 Limit class B
EMC immunity
According to IEC 60801/
DIN VDE 0843
Conducted interferences on AC
supply lines
• According to Part 4 (burst)
• According to Part 5 (ms pulses),
line against line
• According to Part 5 (ms pulses),
line against ground
2 kV
1 kV
2 kV
Conducted interferences on signal
lines
• According to Part 4 (burst)
1 kV
Immunity to static discharge
• According to Part 2 (ESD)
8 kV
Immunity to fields
• According to Part 3 and Part 6
10 V/m
Safety
Electrical safety
IEC 61010 / DIN VDE 0411
Explosion protection
ATEX and IEC Ex:
II 2 G Ex d IIC T4 Gb
Class I, Zone 1, Group IIB + H2 T4
Class I, Div 1, Groups B, C, D T4
Factory Sealed
Oven
Number/type
1 / isothermal
Purging with N2
Possible
Dimensions (D x H)
160 x 10 mm
Max. heating power
35 VA
Temperature range
60 … 165 °C
Temperature stability
± 0.1 K (60 ... 165 °C)
Temperature accuracy
± 3 K (60 ... 165 °C)
Retention time variations per 10 °C
change in ambient temperature
Approx. 0.3 %
Warm-up period from 30 … 100 °C
10 minutes
Siemens AP 01 · 2015
3/31
© Siemens AG 2015
Process Gas Chromatographs
SITRANS CV
Columns and gases
Separating column switching
3
Detectors, calibration and performance data
Multidimensional chromatography
with backflushing and cut in live
system
Detector type
TCD, max. 8 sensors
Cell volume
0.02 µl
Multifunctional diaphragm valve
For injection and backflushing
Calibration
Manual or automatic, single level
Gas connections
Swagelok 1/8"
Repeatability for calorific value and
density
≤ 0.01 % (for natural gas)
Pressure regulators
Max. 4 single-channel electronic
pressure regulators
Accuracy for calorific value and
density
≤ 0.1 % (for natural gas)
Solenoid valves for control of
diaphragm valve
2 NC contacts, 2 NO contacts
Linear range
Typically ≥ 104
Carrier gas
He, Ar
Cycle time
Application-dependent
Notice:
Ambient temperature influence
Negligible
The carrier gas defined for the
delivered state must be used.
Mean Time to Repair/MTBF
< 1 hour / 3 years
(without consumables)
Changing the carrier gas could
destroy the thermal conductivity
detectors.
≥ 99.999 % (5.0)
< 0.1 μm
Degree of separation 99.99 % for
0.1 μm particles
< 35 ml/min
500 …700 kPa
Electronics: Communication and analytical controller (CAC)
• Gas purity (minimum requirement)
• Solid components
• Required filtration
• Consumption
• Inlet pressure
Microprocessor
Intel 586 architecture
Flash EPROM
128 MB
Dynamic RAM
64 MB
Operating system
Windows CE 5.0
Software
Preinstalled. Modifications or
upgrades for operation PC downloadable via network or locally
600 kPa (g) recommended
Important:
A continuous carrier gas supply is
required for error-free operation (frequent carrier gas failure has a negative effect on the life cycle of the
detectors and the device-internal
pressure regulator). In addition, an
external two-layer pressure regulator for the carrier gas pressure is
strongly recommended.
Electronics: Realtime signal processor (RSP)
Microprocessor
Motorola 68376, 20 MHz
Flash EPROM
1 MB
Static RAM
1 MB
Operating system
Forth
Software
Preinstalled. Modifications or
upgrades downloadable via internal
service interface
Not required
Instrument air
Interfaces
Sample and injection
Sample streams
3
Communication
1 x Ethernet 10BaseT/TCP/IP
Calibration sample streams
1
Control system coupling
1 x Modbus RS 485/RS 232 RTU/
ASCII
Phase
Gaseous
Permissible sample pressure
10 … 60 kPa above atmospheric
pressure
NOTICE: Sample must not contain
ethine (acetylene).
Sample flow
20 … 100 ml/min
Max. sample temperature
120 °C
Solid components
< 0.1 μm
Required filtration
Degree of separation 99.99 %
for 0.1 μm particles
Material with which the sample comes
into contact
Stainless steel, fused silica,
polyimide
Injection
• Controller
"Valveless" live injection
With multifunctional diaphragm
valve
From 2 ... 50 μl
• Injection volume adjustable using
switching times
Inputs/outputs: Basic equipment
Digital outputs
(relay contact 0.4 A/24 V DC)
4, 3 x samples, 1 x calibration
Digital inputs (24 V to optocoupler)
4, for 1 = sample flow;
2 = time synchronization;
3 = revision (results have no effect
on average values);
4 = calibration
Status indicator
LEDs for
•
•
•
•
•
•
Supply voltage
Software Heartbeat
Ready
Maintenance request alert
Fault
Sample flow
LCD for
• Sample stream: S1, S2, S3, S4
• Sample components: e.g. CO2,
propane, etc.
• Measured value of sample as
numeric value
Recommended operator panel
3/32
Siemens AP 01 · 2015
Personal computer
Desktop or laptop
Processor
At least Pentium III
Clock
≥ 800 MHz
Interfaces
1 x Ethernet
Operating system
Windows XP, Windows 7
Software
CV Control version 1.30.0.0 and
higher
© Siemens AG 2015
Process Gas Chromatographs
SITRANS CV
Selection and ordering data
Article No.
SITRANS CV process gas chromatograph
Basic unit (incl. application module)
mounted on mounting bracket
Explosion-proof, for Zone 1
Power supply 24 V DC
For 3 sample streams + 1 calibration stream
For ambient temperatures from -20 ... +55 °C
Stand-alone communication via 1 RS 485, RS 232
interface (MODBUS RTU, ASCII)
For post, pipe or wall mounting
Includes CV Control operating software (English)
7KQ3105-
Notes on 7KQ3105-..
Support bracket
7
For easy mounting, incl. support for 8 gas connections
consisting of:
• Mounting part: Dimensions 380 x 110 mm (W x H)
• Bracket for gas connection: Dimensions 146 x 110 mm
(D x H), bracket on right side, mounted at right angle
Sample flow switchover
The chromatograph enables automatic selection and switchover
of 3 sample flows and 1 calibration flow. The DO signal from the
gas chromatograph requires an external relay for the solenoid
valve. The sample preparation system can be ordered
separately.
Click on the Article No. for the online configuration
in the PIA Life Cycle Portal.
Applications
For standard calorific value analysis
(N2, CO2, C1-C5, C6+)
0
For extended calorific value analysis with oxygen
(N2, CO2, O2, C1-C5, C6+)
1
For calorific value analysis with biomethane
(N2, H2, CO2, O2, C1-C4)
2
For calorific value analysis (N2, CO2, C1-C5, C6+)
backflush summation
3
Additional versions
Ambient temperatures
Particularly in warmer zones, weather protection is necessary to
protect the SITRANS CV against direct solar radiation.
The chromatograph is designed as standard for temperatures
from -20 to +55 °C. A version in a thermostatically-controlled
casing is also available as an option for temperatures outside
these limits.
Order code
Communication
Add "-Z" to Article No. and specify Order code
SITRANS CV has a serial interface (RS 485/RS 232) for MODBUS
communication (RTU/ASCII). Modbus mapping can be flexibly
used (see manual for more information).
Russian configuration
Russian configuration for extended calorific
value analysis
A01
The operator input is by means of another separate interface via
Ethernet (TCP/IP).
Extended measuring range in combination
with position 8_0 and position 8_1
N2, C02, C1-C5, C6, C7 (+)
B02
Other serial and analog (4 to 20 mA) interfaces are optionally
possible using an external solution package (see Article No.
7KQ2160).
N2, C02, C1-C5, C6, C7, C8, C9 (+)
Acceptance and customer information
(in agreement with application laboratory)
Documentation
Factory acceptance, 1 day
D01
Factory acceptance (performance record), 1 day
D02
Factory acceptance, every additional day
D03
The documentation includes a SITRANS CV Manual and
CVControl Operating Manual in English and German. The
documents can be found on the enclosed CD.
Proof of repeatability
Safety manuals in all EU languages are also available on the CD.
Repeatability up to 8 h
E01
Repeatability up to 24 h
E02
Repeatability up to 48 h
E03
Selection and ordering data
Article No.
Analog data transmission and serial interface
External module for generation of analog and serial
interfaces
7KQ2160- 7 7 7
CVControl operating software
The operating software (language: English or Russian) is
included in the scope of supply. Windows XP or Windows 7 must
be installed on the computer in order to install this software.
A general system check is made of the basic unit and the
integrated application module. The module and basic unit are
described in the manual. In addition to the standard configuration, additional country-specific and user-specific sub-configurations are available. The performance record ex works
contains the analysis check, including a repeatability record (4h
test).
Click on the Article No. for the online configuration in
the PIA Life Cycle Portal.
Analog values via external unit (standard package)
2 analog values
0
4 analog values
1
8 analog values
The chromatograph is preconfigured; In addition, three
CD-ROMS are enclosed:
• SITRANS CV Software (including manuals and CVControl
Operating Instructions)
• Country-specific sub-setups
• Parameter backup
2
1)
16 analog values
3
20 analog values1)
4
Application
MODBUS multiplexer
Without multiplexer
A
Without CE certificate
B
With CE certificate
C
Enclosure
Without protective casing
A
With protective casing
B
1)
On request
Siemens AP 01 · 2015
3/33
3
© Siemens AG 2015
Process Gas Chromatographs
SITRANS CV
Article No. Pos. 8_0: Applications –
Standard calorific value analysis
Article No. Position 8_3: Applications – Calorific value analysis
with backflush summation
This application comprises the standard calorific value analysis.
The chromatograph's measurement method is set at the factory,
using a synthetic natural gas mixture. The performance parameters specified in Table 5 and the criteria explained in the
subsequent text apply to the individual components in Table 1
and their physical variables.
This position includes the analysis of the components listed in
Table 4, in which case the components starting from C6, including the isomers, are regarded as the sum peak. This variant is
especially well suited for natural gases with very low content of
higher hydrocarbons, especially C6+.
The calculation of the calorimetric variables is possible
according to the following standards: ISO 6976-95, GOST,
AGA 8, where the former is preset. The reference states for the
combustion and for the gas volume that must be specified for
calculation purposes are preset to the standard state (Tb=25 °C,
Tn = 0 °C) and can be easily changed to other reference states
during commissioning using the operating software (Tb=
operating temperature, Tn= standard temperature).
3
However, this backflush summation can also be used to effectively analyze natural gas with typical C6+ fractions. The components up to and including C6+ can be analyzed within the
possible concentration ranges according to Table 4.
A01 – SITRANS CV for calorific value analysis Pos. 8_0, 8_1, 8_2
und 8_3 – Russian configuration
This position includes the possibility for ordering SITRANS CV
with a Russian Ex certificate.
The CVControl software provides the energy units BTU/ft3,
KWh/m3 and MJ/m3.
IMPORTANT: This Russian version results in a change in the
nomenclature from SITRANS CV to MicroSAM.
Article No. Pos. 8_1: Applications – extended calorific value
analysis with oxygen
The following also applies to Pos. 8_3:
The limits listed in GOST Standard 31371.7-2008 are checked
during the inspection and supplied with the device documentation.
This position includes the extended calorific value analysis of the
components and possible working ranges from Table 1. Oxygen
is measured in addition to the listed components (see Table 2).
A carrier gas dry filter (Article No. filter set A5E00400116) on the
mounting bracket of the SITRANS CV or enclosed separately is
used as standard for this measurement.
The remarks concerning oxygen and CO in footnote 1 of Table 1
are no longer applicable to this position. The information
concerning calculation and performance parameters are
identical to Pos. 8_0.
Important:
For correct operation of SITRANS CV in accordance with Pos.
8_0 and 8_1, all measured components must be present in the
calibration gas. The calibration gases listed in the table "Recommended calibration gases for Pos. 8_0 and 8_1" are recommended (also see Table 6):
Component
Pos. 8_0 (mol%)
Oxygen
Pos. 8_1 (mol%)
0.5
B02- SITRANS CV with extended measuring range in combination with Pos. 8_0
This position permits separate measurement of the group
isomers of the higher hydrocarbons C6 to C7(+) and C6 to C9
(+). In accordance with the designation C7(+) and C9 (+), a
detailed measurement is carried out up to and including n-C9.
Important:
Testing and certification of the SITRANS CV is carried out using
the standard calorific value analysis in accordance with
Pos. 8_0. If Pos. D02 or D03 has been selected, this does not
include repetition of the proof of repeatability (4 h test) of the unit
during the factory acceptance.
The following calibration gases are essential for operation of the
SITRANS CV including these extended measuring ranges:
Required
components
Calibration gas for C6
Calibration gas
and C7(+) measurement for C6 and C9(+)
(mol%)
measurement
(mol%)
Nitrogen
4
4
Carbon dioxide
1.5
1.5
Nitrogen
4.00
4.00
Methane
88.9
88.4
Carbon dioxide
1.50
1.50
Ethane
4
4
Methane
89,00
89,00
Propane
1
1
Ethane
4.00
4.00
Isobutane
0.2
0.2
Propane
1.00
1.00
n-butane
0.2
0.2
Isobutane
0.20
0.20
Neopentane
0.05
0.05
n-butane
0.20
0.20
Isopentane
0.05
0.05
Neopentane
0.10
0.10
n-pentane
0.05
0.05
Isopentane
0.05
0.05
n-hexane
0.05
0.05
n-pentane
0.05
0.05
n-hexane
0.05
0.05
n-heptane
0.05
0.05
Table 7: Recommended calibration gases for Pos. 8_0 and 8_1
A summary of the various country-specific setups, i.e. standard
settings including measured components and calibration gases,
can be found on the parameter backup CD in the "Readme.pdf"
document.
Article No. Pos. 8_2: Applications – Calorific analysis with
biomethane
This position contains the analysis of the components and
working ranges of the biomethane listed in Table 3. Based on the
measured concentrations of the components, the quality parameters – such as heating values – are determined in accordance
with the international standards ISO, GOST and AGA analogously to positions 8_0 and 8_1.
3/34
Siemens AP 01 · 2015
n-octane
0.05
n-nonane
0.05
Table 8: Components and concentrations of the calibration gases for the
extended measuring ranges
Further information regarding startup of SITRANS CV including
C7(+) and C9(+) measurement can be found in the manual and
on the enclosed document CD (country-specific setup
"Readme.pdf" file)
© Siemens AG 2015
Process Gas Chromatographs
SITRANS CV
D01 - Acceptance and customer information - Factory
acceptance, visual check, 1 day
Component
Gas #1 (Mol.%)
Gas #2 (Mol.%)
Gas #3 (Mol.%)
Methane
Residual
(approx. 75)
Residual
(approx. 85)
Residual
(approx. 96.5)
Nitrogen
15.5
5
2.5
Carbon dioxide
0.5
2
0.1
Oxygen
0.5
2
4
Ethane
8
4
0.5
The scope of the tests to be carried out is described in Table 9
"Scope of tests during factory acceptance". When ordering D02,
please supplement the desired option from E0x.
Propane
0.5
2
0.15
i-butane
0.15
0.5
0.03
n-butane
0.15
0.5
0.03
Record of component isolation
Neopentane
0.08
0.3
0.03
i-pentane
0.08
0.3
0.03
n-pentane
0.08
0.3
0.03
Hexane
0.05
0.1
0.015
The scope of supply is checked and the documentation and
operation of the unit explained as part of the factory acceptance
process. The factory acceptance does not include repetition of
the proof of repeatability (4 h test) of the unit.
D02 - Acceptance and customer information - Factory
acceptance with performance record, 1 day
Stability test (repeatability)
Checking the Modbus connection
Through a final check of existing
documentation and according to
current chromatograms, 5 analyses
According to order E01 ... E03
Performance criteria according to
page 3/28 ff.
Checking or simulation of Modbus
communication can be carried out
using a flow computer provided by
the customer, for example.
Calculation test
Comparison of the values calculated
by CVControl with a customer comparison procedure (optional)
Auto-calibration function
Auto-optimization of method
The two functions are explained theoretically and practically during presentation of CVControl.
Alarm and event messages
Simulation of alarm situations;
as per customer requirement
Table 8: Scope of test during factory acceptance
SITRANS CV is a standard product. Only in this manner is it
possible to guarantee short delivery times and attractive prices.
All performance records required retrospectively require higher
overhead. However, will will be happy to come to an agreement
regarding implementation.
D03 - Acceptance and customer information - Factory
acceptance, each additional day
Only in conjunction with D01 or D02
E0x - Repeatability test
Proof of repeatability over a period of 4 h is included as
standard. Longer repeatability records for the unit can be
ordered by means of the supplementary item E0x.
E01 to E03 - Repeatability test, 8 h – 24 h – 48 h
Only in conjunction with D02
Linearity tests can be carried out in the factory on request. The
standard calibration gases required for this (Table 10: "Recommended calibration gases for linearity test during acceptance")
are provided free of charge. If the customer specifies other
calibration gases with different compositions or higher uncertainty requirements, they must provide these gases for acceptance purposes. As an option, Siemens can procure these
special calibration gases (subject to a charge).
On request, proof of the complete functionality of the
SITRANS CV is possible within the certified temperature and
ambient conditions.
Table 10: Recommended calibration gases for linearity test during
acceptance
The calibration gases have the following uncertainties:
Proportions of
component materials (Mol.%)
Uncertainty (or smaller)
0.1 ... 0.25
± 5.00 %
0.25 ... 1
± 1.00 %
1 ... 10
± 0.50 %
10 ... 100
± 0.20 %
Table 11: Uncertainties of calibration gases
Notes on 7KQ2160-..
Analog and serial data transmission
SITRANS CV does not provide internal analog outputs. These
properties can be provided by the SIMATIC Extension Unit.
This uses the Modbus output of the chromatograph in order to
generate up to 8 active analog outputs (standard, more analog
outputs on request).
Modbus multiplexers are available in addition, and allow up to
2 Modbus masters to be connected to the SITRANS CV. The
distance from the SITRANS CV should not be more than
1 200 m. In the case of an installation without enclosure (without
explosion protection), we deliver the components for generation
of analog outputs mounted on a rail, otherwise in the Ex d
enclosure.
Pos. 08_ 0 - 5 – Analog values via external unit
This position includes:
• Mounting rail
• Power supply
• SIMATIC S 7-300 and SIMATIC S7, Micro Memory Card 3.3 V
NFLASH, 64 KB
• Analog output module with terminating connector
• Protocol converter
Pos. 09_ A – C: Modbus multiplexer
(only applicable together with 0-4)
The Modbus signal can be routed using the Modbus multiplexer
and connected to two Modbus masters. B specifies supply of
the components without CE certificate.
Pos. 10_ A - B: Enclosure
This position includes the option for installation of the SIMATIC
extension unit in the hazardous area (Zone 1 and Zone 2). A
protective casing Ex d with standard cable glands including the
modules required for the analog outputs and the Modbus multiplexer (if applicable) are provided for this purpose.
Siemens AP 01 · 2015
3/35
3
© Siemens AG 2015
Process Gas Chromatographs
SITRANS CV
■ Dimensional drawings
200
70
12
300
156
20
3
40 34
85
306
20
1
5
4
8
40
220
40
L = 4 000 mm
D 10 (4x)
SITRANS CV, dimensions in mm
3/36
Siemens AP 01 · 2015