Methods for periodical re-verification of heat meters Replacement of all heat meters e.g. with 5 years interval (most used principle in Europe) Statistical sample test (mainly used in Denmark) AMR based meter fleet surveillance (accepted by DANAK in Denmark)
Facts about AMR based meter fleet surveillance 5 years field experience 7308 installations made from 2004 to 2009 20 Heat utilities in Denmark are using this method Accepted by DANAK in February 2006
Interval (Years) AMR based meter fleet surveillance 7 Re-verification intervals in Europe (or no official rules for re-verification of heat meters) 6 5 4 3 2 1 0 Austria Belgium Cyprus Czech Rep. Denmark Estonia Finland France Germany Greece Hungary Ireland Italy Latvia Lithuania Luxembourg Malta Netherlands Poland Portugal Slovakia Slovenia Spain Sweden United Kingdom Iceland Norway Switzerland Source: Working group Thermal Energy within AQUA, Sep. 2008
The principles behind AMR based meter fleet surveillance
Odd meter numbers UTILITY SIDE HEAT METER COMSUMER SIDE Even meter numbers UTILITY SIDE HEAT METER COMSUMER SIDE
The heat meters used for AMR based meter fleet surveillance
AMR-based heat calculator for 2 flow meters and 3 temperature sensors Long-life flow meters qp 0.6 1000 m 3 /h. Insensitive to flow disturbances and magnetite
Parallel The ultrasonic beam runs in parallel with the measuring pipe and is transmitted from the transducers via the reflectors Triangle The ultrasonic beam covers the measuring pipe in a triangle. The ultrasonic beam is transmitted from the transducers and reflected in a triangle to cover the measuring pipe
Temperature loss/meter pipe (K) AMR based meter fleet surveillance Temperature loss in steel pipes 2 1,8 1,6 Reference conditions Water: 55 C Ambient: 23 C 1,4 1,2 Non isolated ¾ black steel pipe 1 0,8 0,6 0,4 0,2 Foam isolated ¾ 0 10 100 1000 black steel pipe Flow rate (Liter/hour)
Non isolated Max. pipe distances between sensors when allowing up to 0.25 K error at qi (15 liter/hour) Foam isolated ¾ black steel pipe
Results from AMR based meter fleet surveillance
Deviation E2-E1 (%) AMR based meter fleet surveillance 10 E2 -E1 % deviation per May 2004 Max. in-service-error set by the surveillance system 8 6 4 2 0-2 0 100 200 300 400 500-4 -6-8 -10 Max. in-service-error acc. to the Danish rules Number of heat meter installations (357 meters per May 2004)
Deviation E2-E1 (%) AMR based meter fleet surveillance 10 E2 -E1 % deviation per May 2009 Max. in-service-error set by the surveillance system 8 6 4 2 0-2 0 100 200 300 400 500-4 -6-8 -10 Max. in-service-error acc. to the Danish rules Number of heat meter installations (471 meters per May 2009)
Main meter in relation to check meter in % (E2-E1)/E1*100 % AMR based meter fleet surveillance Flow meters in flow pipe and return pipe, wrongly installed 10 8 6 4 2 0-2 -4-6 -8 0 2 4 6 8 10 12 14 16 18 20 Flow pipe sensor were mounted in return pipe and vice versa Date of corrected installations 4319826 4319827 4319828 4475234 4475239 4475290 4475302-10 Number of data readings (weekly) Due to the water density, the inlet is about 2.2% higher than the outlet at the temperature sets 75 C/27 C. This means approx. 4.4% error when the flow sensors are wrongly installed.
Deviation in K AMR based meter fleet surveillance Deviations in temperature sensor validations 0,5 0,4 0,3 0,2 0,1 0-0,1-0,2-0,3 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 4319827 4319828 4475317 4475368 4475371 4475227 4475242 4475246 4475258 4475268 4475484-0,4-0,5 Measurements per week Max. in-service-error set by the surveillance system
Measurement error i % AMR based meter fleet surveillance Compliance between system result and Laboratory re-verification (complete heat meters) 15 10 5 0 0,01 0,1 1 10-5 4475380F 4475271F 4475345F 4475294F 4475273F MDIR07.01-01 MDIR07.01-01 -10-15 Flow (m3/h) 3qi - 0,1qp - 0,7qp Max. in-service-error acc. to the Danish rules
Cost comparison between: Replacement of all heat meters with 5 years interval and AMR based meter fleet surveillance
Euro s per meter AMR based meter fleet surveillance Accumulated cost of new meters and installations 800 700 600 500 AMR based Ultrasonic heat meters Standard heat meters 400 300 200 100 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Years of service
Advantages with AMR based meter fleet surveillance Environmental savings because heat meters are in service as long as they are performing well Economical savings for the heat supplier Heat loss due to defective meters is reduced to a minimum
Advantages with AMR based meter fleet surveillance Meter surveillance in real installations means also surveillance of the impact of e.g. flow disturbances AMR and leak surveillance are included, meaning economical savings on meter reading and reduced supply water Efficient fraud detection
Thank you for your attention! Søren Lang Product Group Manager Meter Division, Heat, Cooling and Water E-mail: SL@kamstrup.dk