Natural Gas Metering Options
Natural Gas Metering Options
(OP)
Hi Guys,
I'm looking for some direction in picking meters to monitor Natural Gas flow and consumption.
I have a number of large box fires operating at max fire rate of 8 million Btus/hr, and am trying to decide on a technology to meter the amount of gas they use in an hour.
I'd like to stay in the realm of Mass Flow, if possible, but cost could make me move to volumetric calculation.
Does anyone have any experience to share with monitoring Natural Gas with Coriolis or Thermal Mass Flowmeters? Thermal Mass meters sounded promising, but I'm told they are subject to large amounts of drift over time.
Ideally, I'd like a meter that requires little maintenance, and is easy to calibrate.
For reference, the pipe size I'm working with is 2" sched. 40, with Natural Gas at 18psi. Turndown is a consideration as well, as my furnaces can go to low fire of around .5 million Btu/hr.
Any experiences/recommendations?
-Matt!
I'm looking for some direction in picking meters to monitor Natural Gas flow and consumption.
I have a number of large box fires operating at max fire rate of 8 million Btus/hr, and am trying to decide on a technology to meter the amount of gas they use in an hour.
I'd like to stay in the realm of Mass Flow, if possible, but cost could make me move to volumetric calculation.
Does anyone have any experience to share with monitoring Natural Gas with Coriolis or Thermal Mass Flowmeters? Thermal Mass meters sounded promising, but I'm told they are subject to large amounts of drift over time.
Ideally, I'd like a meter that requires little maintenance, and is easy to calibrate.
For reference, the pipe size I'm working with is 2" sched. 40, with Natural Gas at 18psi. Turndown is a consideration as well, as my furnaces can go to low fire of around .5 million Btu/hr.
Any experiences/recommendations?
-Matt!





RE: Natural Gas Metering Options
For higher turndowns, I prefer corriolis massflow meters. Calibration for these meters can't be done at site easily.
Regards,
RE: Natural Gas Metering Options
www.daniel.com
RE: Natural Gas Metering Options
RE: Natural Gas Metering Options
Orifice plates are pretty common in this type of service. Ultrasonics are another option. I don't have any experience with thermal meters to comment.
RE: Natural Gas Metering Options
Just my two cents.
chris
RE: Natural Gas Metering Options
Friar Tuck of Sherwood
RE: Natural Gas Metering Options
RE: Natural Gas Metering Options
Calorific values for gas are normally stated in volumetric units and therefore doesn't it make more sense to measure that value?
Incidentally, we use turbine meters which have a very low pressure drop and have built in digital outputs which we send to BMS (Building Management Systems).
Friar Tuck of Sherwood
RE: Natural Gas Metering Options
This article deals with natural gas flow measurement by dp and turbine meters.
http://www.flowmeterdirectory.com/flowmeter_artc/f...
Regards,
RE: Natural Gas Metering Options
RE: Natural Gas Metering Options
without sufficient the fluid density the vibrating or vortex shedding methods don't work.
keep in mind that the turbine types do require protection against overspeed and need provison for oiling on line (if the bearings arn't sealed.
RE: Natural Gas Metering Options
I regard any head type meter as limited to about 5:1 even with today's accuracy. The burners too have limited turndown. I would not object to orifice plate technologies at this size.
What precision is required - and why?
John
RE: Natural Gas Metering Options
RE: Natural Gas Metering Options
To answer your questions:
-Volumes are 9000 scfh or so at max fire, 500 scfh or so at min fire.
-Volumetric meters require pressure & temp compensation for calculations, mass flow meters do not. I'd prefer to not backwards engineer the BTU content per scfh if possible. Really, this is just a way to remove some error if I can.
-Precision: I'd like +/- 1.5% total error, if possible. Mainly, the meters will be used to prove out process improvements and to try to troubleshoot why one furnace may be running differently than another.
-Matt!
RE: Natural Gas Metering Options
These days a guy could strap a Rosemount or equivalent dP meter to the side for telemetry out to a surface datum logger or signal processing unit. Either way, that would proove far more costly than orifice/venturi meter itself!
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada
RE: Natural Gas Metering Options
Check out V-cones. Very accurate and repeatable.
http://www.mccrometer.com/products/pdvcone.htm
They are less expensive, but do require corrections for pressure and temperature.
They also do not require extensive upstream and downstream piping runs.
On my installation, they saved a bundle due to the piping configuration.
RE: Natural Gas Metering Options
BTW, I saw a new element at ISA with a venturi and annubar that has the benefits of a V-cone and better accuracy. I have no experience but am interested in this technology.
John
RE: Natural Gas Metering Options