1. Multi gas air ratio control platform (MGARCP)
of DVGW-EBI
to manage gas quality effects on appliance site
MARCOGAZ Gas Sensor Workshop
DVGW Research Centre at the Engler-Bunte-Institute
Dr. Holger Dörr
DVGW-Forschungsstelle am Engler-Bunte-Institut des Karlsruher Instituts für Technologie · Prüflaboratorium Gas

2. Outline Impacts of gas qualities on appliances Scope of MGARCP
Approach of MGARCP
Gas quality sensors: Measured properties
Experimental setup for gas quality sensor tests
Conclusions
DVGW-Forschungsstelle am Engler-Bunte-Institut des Karlsruher Instituts für Technologie · Prüflaboratorium Gas

3. Impacts of gas qualities on appliances
Gas quality fluctuations have effects on
emissions (CO, NOx, CxHy)
power (thermal, process heat input)
process quality and stability (temperature fields, flame lengths, ...)
Several adaptive gas-air-ratio-controls for gas appliances are available
Ionization based methods (SCOT and variants, domestic)
CO ZrO-based flue probes (non-domestic, less domestic)
O2-ZrO-based l flue probes (non-domestic)
CO/O2-ZrO-based flue probes (non-domestic)
temperature probe on burner surface (e.g. LambdaConstant, domestic)
DVGW-Forschungsstelle am Engler-Bunte-Institut des Karlsruher Instituts für Technologie · Prüflaboratorium Gas

4. Impacts of gas qualities on appliances
Harmonization of Natural Gas Quality CEN/TC 234 WG 11, CEN/TC 408
Dis-harmony in European Natural Gas Market(s)—Discussion of Standards and Definitions, Z. Energiewirtschaft, (2013), by: P. Drasdo, M. Karasz, A. Pustisek
Test gases are specified within EN 437
Recommended gas qualities are introduced in product standards
(e.g. EN Appendix DD)
Liberalisation of gas trading has certain effects on gas qualities and thereby on appliance operation, efficiencies and emissions
Not only ErP requires decreasing NOx-emissions (or CO, unburned CxHy)
Especially with high caloric gas qualities (LNG) NOx-formation will increase
There is a evolving need for adaptive gas-air-ratio-control for gas appliances!
DVGW-Forschungsstelle am Engler-Bunte-Institut des Karlsruher Instituts für Technologie · Prüflaboratorium Gas

5. Scope of MGARCP Research and development tool
Closely related to our gas quality research and standardisation activities
Self-adaptive control strategies: ideally power and emission adjustment
To understand more deeply self-adaptive control strategies (even the empirical approaches, proper parameterisation)
Tool for comparison of self-adaptive control strategies
Teaching tool especially for correlative gas analysis methods
DVGW-Forschungsstelle am Engler-Bunte-Institut des Karlsruher Instituts für Technologie · Prüflaboratorium Gas

6. MGARCP: Research and development tool
CO-Sensor (CO-Lambda probe)
O2-Lambda probe
Flue gas temperature (Pt100)
Reference measuring instrument:
Flue gas analyzer for CO2, CO, O2, NO, NO2, CxHy,
DVGW-EBI MGARCP:
Multi gas air ratio control platform
Base:
Baxi Duo-tec 33 kW
Condensing boiler-
combi-appliance
post-combustion
Full / partial load
Recording of any sensor
Characteristic curves:
Gas valve
Fan
dSignal/dt: sensitivity
analysis 
Ionisations probe (à la SCOT)
T-field (thermocouples)
in-process /
in-combustion
Heat meter (Power output)
Gas quality sensor
pre-combustion
DVGW-Forschungsstelle am Engler-Bunte-Institut des Karlsruher Instituts für Technologie · Prüflaboratorium Gas

7. Gas quality sensors: Measured properties
Small alkanes: various correlations with number of C-Atoms, molar mass
and velocity of sound,
source: Schley et al.: NEW TECHNOLOGIES FOR GAS QUALITY DETERMINATION (2001)
What's about hydrogen and CO2? No. of sensors, calibration efforts, range
Reference measurement instrumentation: GC, Mass Spectrometry, Infrared-Spectroscopy
DVGW-Forschungsstelle am Engler-Bunte-Institut des Karlsruher Instituts für Technologie · Prüflaboratorium Gas

8. Experimental setup for gas quality sensor tests
cost effective sensor: reduced requirements on measurement uncertainty
Gas quality sensor
Open issues:
admissible concentrations
T90-times
c(H2) > 5 % PGCs with
He as the only carrier gas
will fail
Data acquisition
Data analysis
Gas mixing station
DVGW-Forschungsstelle am Engler-Bunte-Institut des Karlsruher Instituts für Technologie · Prüflaboratorium Gas

9. Experimental setup for gas quality sensor tests
cost effective sensor: reduced requirements on measurement uncertainty
Gas quality sensor
System & Sensor activities at DVGW-EBI
validation
integration
development
Open issues:
admissible concentrations
T90-times
c(H2) > 5 % PGCs with
He as the only carrier gas
will fail
Data acquisition
Data analysis
Gas mixing station
DVGW-Forschungsstelle am Engler-Bunte-Institut des Karlsruher Instituts für Technologie · Prüflaboratorium Gas

10. Conclusions
Gas quality fluctuations will occur more frequently and with higher amplitudes.
There is a growing demand for cost effective gas quality sensors with reduced requirements with regard to measurement uncertainty.
Complexity relates to gas matrix (no. components & concentrations).
Gas quality sensors have to compete with in-process probes or flue gas probes.
There is still a need for more innovative products for natural gas applications!
DVGW-Forschungsstelle am Engler-Bunte-Institut des Karlsruher Instituts für Technologie · Prüflaboratorium Gas

11. Thank you for your attention!
DVGW-Forschungsstelle am Engler-Bunte-Institut des Karlsruher Instituts für Technologie · Prüflaboratorium Gas