# Furnace {-}

```{rosmose furnace}
! OSMOSE ET furnace
```


```{rosmose} 
Tad = 2025 [C] # Adiabatic flame temperature of the fuel 
dtmin_radiation = 2 [C] # radiation delta t mininum
dtmin_convection = 8 [C] # convection delta t mininum
To = 25 [C] # Tamb = To = Tchemicalreference
Trad= 1050 [C] # Radiation temperature threshold, actual temperature is 1050°C but 400 can be used for plot visualization
Tstack = 100 [C] # Stack temperature threshold for no dew point
MWair = 29 [kg/kmol] # Molecular weight of dry air = 79% N2 + 21% O2
MWfuel = 16 [kg/kmol] # Molecular weight of methane
losses = 0.03 [-] # 3% Furnace losses
LHV = 50000 [kJ/kg] # natural gas LHV @ 25°C,1 bar
molratst = 9.52 [kmol/kmol] # Stoich molar air to fuel ratio
a = 1.02 [-] # excess air as in: CH4 + a*2(O2+3.76N2) --> CO2 + 2H2O + 2*3.76N2 + 2(a-1)(O2 + 3.76N2)
cpair = 1.075 [kJ/kg/K] # Air heat capacity @427°C, 1bar (Engineering toolbox)
Tprin = 26 [C] # Preheating temperature
Furnace_natGas_LOAD = 1000 [kW] # Reference furnace load 
Spec_heaterCost = 200 [Euro/kW]
n = 40.0 [yr] #lifetime of a furnace
i = 0.06 [-] #interest rate
CEPCI_2020 = 596.2 [-] # actual CEPCI
CEPCI_2008 = 575.4 [-] # CEPCI 2008
```


```{rosmose} 
v = %molratst% * %MWair% / %MWfuel% [kg/kg] # stoich air to fuel mass ratio
cpg = %Furnace_natGas_LOAD% / (%Tad% - %To%) [kW/K] # Flue gases heat capacity @1bar
Tad_corr = %To% + (%Furnace_natGas_LOAD% / (%cpg% + (%cpair% * (%a% -1) * %v% * %Furnace_natGas_LOAD% / %LHV%))) [C] # Corrected adiabatic flame temperature
cpg_corr = %Furnace_natGas_LOAD% / (%Tad_corr% - %To%) [kW/K] # Corrected flue gases heat capacity @1bar 
Q_rad_gross = (%Furnace_natGas_LOAD% * (%Tad_corr% - %Trad%) / (%Tad_corr% - %To%)) [kW] # Heat flow rate at the radiation threshold temperature
Q_conv_gross = %Furnace_natGas_LOAD% * (%Trad% - %Tstack%) / (%Tad_corr% - %To%) [kW] # Heat flow rate at the convection threshold temperature 
Q_preh = %cpair% * %v% * %Furnace_natGas_LOAD% / %LHV% * (%Tprin% - %To%) [kW] # Air preheating load
Q_stack = %cpg_corr% * (%Tstack% - %To%) [kW] # Stack losses
Q_radpreh = %Q_preh% + %Q_rad_gross% [kW] # Preheating load added to the highest temperature
Q_demand = %Furnace_natGas_LOAD% / (1-%losses%) [kW] # Total energy consumption by the furnace
Annuity = (%i%*(1+%i%)**%n%)/((1+%i%)**%n%-1) [-] #annualization factor
Cinv2_NGFur = %Spec_heaterCost%*%Furnace_natGas_LOAD%*(%CEPCI_2020%/%CEPCI_2008%)*%Annuity% [Euro/y]

```

<!-- ## These are the input and calculated parameters {-} -->

<!-- ```{rosmose} -->
<!-- : TAGS DISPLAY_TAGS [nvuD] -->
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**Layers of the Furnace ET**

```{rosmose} 
: OSMOSE LAYERS furnace

| Layer         | Display name | shortname | Unit | Color |
|:--------------|:-------------|:----------|:-----|:------|
|NATGAS         |Gas           |ng         |kW    |green  |

```

**Furnace unit of the Furnace ET**

```{rosmose} 
: OSMOSE UNIT furnace

|unit name  |type   |
|:----------|:------|
|Furnace    |Utility|
```

**Parameters of the Furnace unit**

```{rosmose Furnace_params}
: OSMOSE UNIT_PARAM Furnace

|cost1  |cost2  |cinv1  |cinv2         |imp1   |imp2   |fmin   |fmax   |
|:------|:------|:------|:-------------|:------|:------|:------|:------|
|0      |0      |0      |%Cinv2_NGFur% |0      |0      |0      |100    |
```


**Furnace Streams**

*Resource Streams*
Defining the resource streams, in this case natural gas to the furnace

```{rosmose Furnace_rs}
: OSMOSE RESOURCE_STREAMS Furnace

|layer      |direction|value                |
|:----------|:--------|:--------------------|
|NATGAS     | in      |%Q_demand%           |
```

*Heat Streams*

```{rosmose Furnace_hs}
: OSMOSE HEAT_STREAMS Furnace

|name       |Tin   |Tout    |Hin            |Hout               |DT min/2           |alpha|
|:----------|:-----|:-------|:--------------|:------------------|:------------------|:----|
|radiation  |%Trad%|%Trad%  |%Q_radpreh%    |0                  |%dtmin_radiation%  |1    |
|convection |%Trad%|%Tstack%|%Q_conv_gross% |0                  |%dtmin_convection% |1    |
|preheating |%To%  |%Tprin% |0              |%Q_preh%           |%dtmin_convection% |1    |
```


## Visualization of Furnace {-}
