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Steam System Modeler Tool (SSMT)
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EERE » Advanced Manufacturing Office » Steam Calculators » Boiler Calculator
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Boiler Calculator
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Determines the amount of fuel energy required to produce steam with specified properties at a given flow rate using general boiler
operational characteristics.
Glossary
Deaerator Pressure*
psig
Value is required and can't be empty
Resources
Combustion Efficiency*
%
Value is required and can't be empty
Blowdown Rate*
%
Value is required and can't be empty
psig
Value is required and can't be empty
Tutorials
Properties Calculators:
Steam
Saturated Properties
Steam Properties
Equipment Calculators:
Boiler
Pressure*
Temperature
Heat Loss
Steam Mass Flow *
Flash Tank
* Required
*
329
°F
klb/hr
Value is required and can't be empty
Enter
PRV w/ Desuperheating
Header
Examples: Mouse Over
Deaerator
Calculation Details and Assumptions below
Steam Turbine
Calculation Details
Steam System Modeler
Step 1: Determine Properties of Steam Produced
Using the Steam Property Calculator, properties are determined using Steam Pressure and the selected second parameter (Temperature,
Specific Enthalpy, Specific Entropy, or Quality). The Specific Enthalpy is then multiplied by the Mass Flow to get the Energy Flow:
Steam Energy Flow = Specific Enthalpy * Mass Flow
Step 2: Determine Feedwater Properties and Mass Flow
The feedwater flow rate can be calculated from steam mass flow and blowdown rate:
1.
2.
3.
4.
Blowdown Mass Flow = Feedwater Mass Flow * Blowdown Rate
Steam Mass Flow = Feedwater Mass Flow - Blowdown Mass Flow
Steam Mass Flow = Feedwater Mass Flow - Feedwater Mass Flow * Blowdown Rate
Feedwater Mass Flow = Steam Mass Flow / [ 1 - Blowdown Rate ]
Using the Steam Property Calculator, properties are determined using Deaerator Pressure and Quality = 0 (Saturated Liquid). The Specific
Enthalpy is then multiplied by the Mass Flow to get the Energy Flow:
Feedwater Energy Flow = Specific Enthalpy * Mass Flow
Step 3: Determine Blowdown Properties and Mass Flow
Using the calculated feedwater mass flow and blowdown rate:
Blowdown Mass Flow = Feedwater Mass Flow * Blowdown Rate
Using the Steam Property Calculator, properties are determined using Steam Pressure and Quality = 0 (Saturated Liquid). The Specific
Enthalpy is then multiplied by the Mass Flow to get the Energy Flow:
Blowdown Energy Flow = Specific Enthalpy * Mass Flow
Step 4: Determine Boiler Energy
Boiler Energy = Steam Energy Flow + Blowdown Energy Flow - Feedwater Energy Flow
Step 5: Determine Fuel Energy
Fuel Energy = Boiler Energy / Combustion Efficiency
Assumptions
Deaerator provides feedwater near the boiling temperature for the deaerator's set operating pressure. (Saturated Liquid)
Steam, Boiler, and Blowdown Pressure are the same.
Combustion Efficiency is the % of fuel energy that is directly added to the feedwater and not otherwise lost or used.
Blowdown Rate is the % of incoming feedwater mass flow rate that leaves the boiler as a saturated liquid at boiler pressure.
Does not include any evaluation of any complex boiler configurations or fluctuations in operation.
Energy from motors (pumps, fans, etc.) are not considered.
Boiler and fuel types are not considered.
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Version: v0.9 - Build Date: 3/17/2015