Liquid Controls SP4000 - Manual (Page 25)

SP4000 Flow Computer
22
3.10 Steam Heat
Measurements:
A flowmeter measures the actual volume flow in a steam line. A temperature and/or
pressure sensor is installed to measure temperature and/or pressure.
Calculations:
• Density, mass flow and heat flow are calculated using the steam tables stored in the
flow computer. The heat is defined as the enthalpy of steam under actual conditions
with reference to the enthalpy of water at T=0
°
C.
• Saturated steam requires either a pressure or temperature measurement with the
other variable calculated using the saturated steam curve.
• Optional steam trap monitoring using compensation input.
Input Variables:
Superheated Steam: Flow, temperature and pressure
Saturated Steam: Flow, temperature or pressure
Output Results:
• Display Results
Heat, Mass or Volume Flow Rate, Resettable Total, Non-Resettable Total,
Temperature, Pressure, Density (optional: peak demand, demand last hour,
time/date stamp)
• Analog Output
Heat, Mass or Volume Flow Rate, Temperature, Pressure, Density, Peak
Demand, Demand Last Hour
• Pulse Output
Heat, Mass or Volume Total
• Relay Outputs
Heat, Mass or Volume Flow Rate , Total, Pressure, Temperature Alarms, Peak
Demand, Demand Last Hour
Applications:
Monitoring heat flow and total heat of steam. Flow alarms are provided via relays and
datalogging is available via analog (4-20mA) and serial outputs.
STEAM HEAT
Heat Flow
Heat Flow = Volume flow • density (T, p) • Sp. Enthalpy of steam (T, p)
Calculations
Steam Heat
Illustration
Flowmeter Temperature
Transmitter
PRINT
5
0 –
TIME
CLEAR
•
MENU
ENTER HELP
TEMP
4
PRE 1
3
RATE
2
TOTAL
1
GRAND
6
SCROLL
7
PRE 2
8
DENS
9
Pressure
Transmitter
*
* or Steam Trap Monitor