Endress+Hauser RMS 621 - Customer-Specific Applications

6 Commissioning RMS 621
50 Endress+Hauser
6.5 Customer-specific applications
6.5.1 Steam mass application
Monitoring the superheated steam in a feed pipe of a plant (20 t/h rating, approx.
25 bar). The steam quantity is used to operate the plant. This is never allowed to go below 15 t/h
steam flow. This is to be monitored by the alarm set point in the energy manager and retransmitted
using a relay.
The display of the energy manager is to scroll through one mask containing mass flow, pressure,
temperature and another with summed mass flow.
The following sensors are used for measurement:
• Volume flow: Vortex sensor (e.g. Prowirl)
Legend plate indication: K-factor: 38.9; Signal type: PFM, Alpha-factor: 4.88x10
6
• Pressure: Pressure sensor (e.g. Cerabar; 4 to 20 mA, 0.005 to 40 bar)
• Temperature: Pt100 temperature sensor
1. Flowmeter (Setup-Menu Flow):
Flow 1,
Signal type PFM,
K-factor: 38.9,
th. A coeff.:4.88x108
(operating example see fig. on the left).
2. Pressure sensor (Setup-Menu pressure):
Pressure 1,
Signal type: 4 to 20 mA,
Start value 0.005 bar,
End value 40 bar,
Default 25 bar (Pressure with which the RMS 621 will
continue to operate on sensor failure)
3. Temperature sensor (Setup-Menu temperature):
Temp. 1.1,
Signal type Pt100,
Default (enter the medium expected operating
temperature)
4. Set up application (Setup-Menu application):
Application1,
Steam mass,
Superheated steam,
Flow1,
Pressure 1,
Temp1.1,
Engineering units: Mass flow t/h, Mass sum t
5. Set up display (Setup-Menu display):
Group1: 3 values (mass flow, pressure, temperature)
Group 2: 1 value (mass sum) scrolled: 10 seconds,
Group 1: Yes,
Group 2 : Yes
6. Set up alarm set point:
Relay,
operating mode Min+Alarm,
signal source mass flow,
switch point 15 t/h,
hysteresis 0.5 t/h (this means relay reset at
15.5 t/h)