Presented software bases on new theoretical findings on heat transfer in boilers. It
delivers unprecedented proven +/-2% uncertainty. It can be used to carry out tasks like
these:
Software calculates heat transfer in fossil fuel fired fire-tube steam, hot water and waste
heat boilers of arbitrary geometry and for arbitrary operating conditions (excess air,
pressure up to 99bar/1435psi). Boiler can consist of multiple segments such as furnace,
channels, chambers and tubes, with or without front or/and rear cooled door. The boiler
segments can be combined, which makes calculation of next to every known boiler design
possible.
Following boiler designs and boiler segments can be calculated:
1. Tubular boiler
2. Furnace (combustion chamber)
3. Channel after furnace (if any)
4. Boiler with 1, 2 or 3 tube assemblies after furnace (2-pass, 2-pass reverse flue, 3-
pass, 4-pass)
5. Redirection channel between two tube sets (one in 3-pass and two in 4-pass boilers)
6. Channel before boiler exit (if any)
7. Boiler with cooled rear door.
8. Waste heat boiler or exhaust gas boiler (such as hybrid biomass system) without or
with supplemental firing .
9. Tubular economizer with or without fins (circular or rectangular). Can also be
calculated separately as can stoichiometry of combustion.
Boiler can be made of following materials:
Economizer tubes can be made of following materials:
Boiler liquid can be following:
Input and output values can be either in Metric or English units.
Order of calculations
1. A stoichiometry of the combustion, adiabatic combustion temperature, flue-gas
enthalpy at that temperature, and a first estimation for the furnace exit temperature are
calculated.
2. Convective and radiant parts of the heat transfer are considered to be simultaneously
coexistent. For convection, the relevant temperature is mean logarithmic, for radiation the
mean radiant temperature that is calculated by proprietary procedure.
3. The impact of the turbulators or tube dents is taken into account according to the
proprietary developed procedure.
4. The convective and radiant parts of the heat transfer in the furnace are summed-up
and deducted from the flue gas enthalpy at the adiabatic combustion temperature. The
result is a temperature at the furnace exit.
5. The calculated flue-gas exit temperature is compared to the estimated one in step 1. If
they do not meet the preset difference (0.1°C) a new estimation is calculated as the
average of assumed one in step 1 and just calculated one. The procedure is then
repeated.
6. This same procedure is applied to every boiler segment using the exit temperature of
flue gas from one segment as being the initial temperature in the next section. Thus, the
initial temperature in next boiler section is equivalent to the exit temperature from
preceding section.
7. The sum of the heat transferred in all boiler sections represents its heat output which,
when divided by heat released from fuel, yields the boiler efficiency.
Discrepancy sources between measured and calculated values
There are always differences between calculated and actual values. The discrepancies
are of an operational (fouling, scaling on gas and water side) and of mathematical nature
(heat transfer equations are always derived from experiments). In general, for new and
well maintained boilers the discrepancy to actual values is as low as 2% (boiler output,
steam capacity, efficiency).
delivers unprecedented proven +/-2% uncertainty. It can be used to carry out tasks like
these:
- heat transfer analysis in boilers
- boiler design optimization
- retrofit of installed boilers.
Software calculates heat transfer in fossil fuel fired fire-tube steam, hot water and waste
heat boilers of arbitrary geometry and for arbitrary operating conditions (excess air,
pressure up to 99bar/1435psi). Boiler can consist of multiple segments such as furnace,
channels, chambers and tubes, with or without front or/and rear cooled door. The boiler
segments can be combined, which makes calculation of next to every known boiler design
possible.
Following boiler designs and boiler segments can be calculated:
1. Tubular boiler
- single pass or double pass
- horizontal or vertical
- tubes can have coiled-wire turbulators or dents.
2. Furnace (combustion chamber)
- circular or rectangular
- horizontal or vertical
- with or without rectangular fins
- wetback or dryback
- with or without front cooled door.
3. Channel after furnace (if any)
- one or more
- circular or rectangular
- horizontal or vertical
- with or without rectangular fins
- with or without baffles.
4. Boiler with 1, 2 or 3 tube assemblies after furnace (2-pass, 2-pass reverse flue, 3-
pass, 4-pass)
- horizontal or vertical
- tubes can have coiled-wire turbulators or dents.
5. Redirection channel between two tube sets (one in 3-pass and two in 4-pass boilers)
- circular or rectangular
- horizontal or vertical.
6. Channel before boiler exit (if any)
- one or more
- circular or rectangular
- horizontal or vertical.
7. Boiler with cooled rear door.
8. Waste heat boiler or exhaust gas boiler (such as hybrid biomass system) without or
with supplemental firing .
9. Tubular economizer with or without fins (circular or rectangular). Can also be
calculated separately as can stoichiometry of combustion.
Boiler can be made of following materials:
- boiler steel
- cast iron.
Economizer tubes can be made of following materials:
- steel
- copper.
Boiler liquid can be following:
- water
- Rankine cycle liquid
- thermal oil.
Input and output values can be either in Metric or English units.
Order of calculations
1. A stoichiometry of the combustion, adiabatic combustion temperature, flue-gas
enthalpy at that temperature, and a first estimation for the furnace exit temperature are
calculated.
2. Convective and radiant parts of the heat transfer are considered to be simultaneously
coexistent. For convection, the relevant temperature is mean logarithmic, for radiation the
mean radiant temperature that is calculated by proprietary procedure.
3. The impact of the turbulators or tube dents is taken into account according to the
proprietary developed procedure.
4. The convective and radiant parts of the heat transfer in the furnace are summed-up
and deducted from the flue gas enthalpy at the adiabatic combustion temperature. The
result is a temperature at the furnace exit.
5. The calculated flue-gas exit temperature is compared to the estimated one in step 1. If
they do not meet the preset difference (0.1°C) a new estimation is calculated as the
average of assumed one in step 1 and just calculated one. The procedure is then
repeated.
6. This same procedure is applied to every boiler segment using the exit temperature of
flue gas from one segment as being the initial temperature in the next section. Thus, the
initial temperature in next boiler section is equivalent to the exit temperature from
preceding section.
7. The sum of the heat transferred in all boiler sections represents its heat output which,
when divided by heat released from fuel, yields the boiler efficiency.
Discrepancy sources between measured and calculated values
There are always differences between calculated and actual values. The discrepancies
are of an operational (fouling, scaling on gas and water side) and of mathematical nature
(heat transfer equations are always derived from experiments). In general, for new and
well maintained boilers the discrepancy to actual values is as low as 2% (boiler output,
steam capacity, efficiency).
| BOILER DESIGN SOFTWARE FOR FIRE-TUBE BOILERS |
| INTRODUCTION |
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| DOWNLOAD (pdf file) Calculation and test results comparison summary |