KROHNE VFM 5090 EN - Manual (Page 21)

5.7 Options available with VFM5090(I)
5.7.1 METER TYPE
1. Heat Meter
VFM-5090(I), supports thermal power and energy calculations for Steam and Water. Thermal power is calculated
on line from the mass flow and specific enthalpy, at the operating P&T and thermal energy is calculated by time
integrating (totalizing) thermal power. An energy totalizer is provided to accumulate the thermal energy.
The thermal power can be displayed in one of the following units -
KJ/hr, MJ/hr, GJ/hr, BTU/hr, KCal/hr, KW and MW.
Corresponding units for energy display are - KJ, MJ, GJ, BTU, KCal, KWh and MWh.
2. FAD Meter
An air compressor sucks in air from the atmosphere and delivers it compressed to the required pressure. Since
atmospheric air contains water vapour, what the compressor actually sucks in is a mixture of air and water vapour.
Under these conditions the Free Air Delivery specification of the compressor is not directly and easily known.
Almost all manufacturers specify FAD at standard suction conditions only. What the user gets to use as eventual
plant air or process air needs to be found out and hence metered with ease and a reasonable accuracy of at least
±1%.
VFM 5090(I) FAD-METER can measure FAD on-line, compensated for humidity and RPM apart from its use as
STD FLOWMETER.The software built into the meter evaluates the FAD automatically on line. The menu driven
user friendly software prompts the user for information like ambient temperature, pressure and relative humidity,
design & actual RPM, and discharge pressure. The steam tables and compressibility data are programmed into the
memory as a standard feature. There is a temperature sensor which measures on line discharge temperature. The
meter is also available with an optional pressure sensor which measures the discharge pressure on-line eliminating
the need to feed in the value manually.
3. AGA Natural Gas Meter
The special version software is made with added capability for density computation according to American Gas
Association (AGA) standards.
AGA Natural Gas Meter - This software is made with the purpose of using VFM5090(I) Meter as a Natural Gas
meter which accurately calculates the density value of the gas mixture at given temperature and pressure so that
the mass flow and normalized mass flow calculations will be very much accurate. Please note that this is a special
version and supports only natural gas and gas mixture applications.
Heat Meter - The same software can be used to calculate the thermal power and energy for natural gas
applications. Heat value of the gas mixture is also available. Thermal power at the operating P&T is calculated on
line using the composition of natural gas. Thermal energy is calculated by time integrating (totalizing) thermal
power. An energy totalizer is provided to accumulate the thermal energy.
Heat value, compressibility factor and thermal power at the operating P & T is calculated on line using the
composition of natural gas.
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