KEP ES749 - 3.6 Gas Mass

ES749 Flow Computer
16
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
Orifice Plate
with DP Transmitter
FlowmeterTemperature
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
3.6 Gas Mass
Measurements:
A owmeter measures the actual volume ow in a gas line. Temperature and pressure
sensors are installed to measure temperature and pressure.
Calculations:
• Density and mass ow are calculated using gas characteristics stored in the ow
computer.
• With square law device measurement the actual volume is calculated from the
differential pressure, taking into account temperature and pressure compensation.
Output Results:
• Display Results
Mass or Volume Flow Rate, Resettable Total, Non-Resettable Total, Temperature,
Pressure, Density (optional: peak demand, demand last hour, time/date stamp)
• Analog Output
Mass or Volume Flow Rate, Temperature, Pressure, Density, Peak Demand,
Demand Last Hour
• Pulse Output
Mass or Volume Total
• Relay Outputs
Mass or Volume Flow Rate, Total, Pressure, Temperature, Density Alarms, Peak
Demand, Demand Last Hour
Applications:
Monitoring mass ow and total of gas. Flow alarms are provided via relays and datalogging
is available via analog (4-20mA) and serial outputs.
GAS MASS
Mass Flow
P T
ref
Z
ref
Mass Flow = Actual Volume Flow • ρ
ref
• • •
P
ref
T Z
ρ
ref
= Reference density
T
ref
= Reference temperature
P
ref
= Reference pressure
Z
ref
= Reference Z-factor
Calculations
Gas Mass
Illustration