Siemens FX300 manual Gross heat meter

2 DEVICE DESCRIPTION
	SITRANS FX300

2.2.5 Gross heat meter

In almost all applications with saturated steam, the steam is used for heating. It is much more interesting to know how great the heat flow volume is that is available to the process, than to know how great the flow is in kg/h.

As the enthalpy of steam changes with the temperature, it cannot be assumed to be constant. The vortex flowmeter has a special feature which calculates the flow of steam and water as power. The enthalpy tables are permanently programmed into the memory of the device.

The online density-compensated mass flow is multiplied by the correct enthalpy to obtain the flow as power output.

Power {QH] = mass flow [Qm] x enthalpy [H]

If the gross heat meter is activated, both the totalizer for the absolute steam consumption as well as that for the energy run internally.

14 www.siemens.com/flow 06/2009 - SFIDK.PS.050.F2.02 A5E02100423