# The Influence of Co-Firing Coal with Biomass Syngas on the Thermodynamic Parameters of a Boiler
## Nomenclature
\begin{tabular}{l l} \(FC_{\rm ar}\) & content of fixed carbon on the as-received basis (\%) \\ \(H\) & area of convective heating surfaces (m\({}^{2}\)) \\ H\({}_{\rm ar}\) & content of hydrogen on the as-received basis (\%) \\ \(i_{\rm s}\) & sensible heat of mixed fuels (kJ kg\({}^{-1}\)) \\ \({}^{\rm coal}_{\rm syngsgs}\) & sensible heat of coal (kJ kg\({}^{-1}\)) \\ \(i_{\rm s}^{\rm o}\) & sensible heat of biomass syngas (kJ kg\({}^{-1}\)) \\ \(l_{\rm c}^{0}\) & enthalpy of cold air (kJ kg\({}^{-1}\)) \\ \(l_{\rm ex}^{\rm o}\) & enthalpy of exhaust gas (kJ kg\({}^{-1}\)) \\ \(l_{\rm d}^{\rm o}\) & enthalpy of flue gas at the furnace exit (kJ kg\({}^{-1}\)) \\ \(k\) & radiant attenuation factor of flue gas (m\({}^{-1}\) MPa\({}^{-1}\)) \\ \(k_{\rm C,q}\) & radiant attenuation factor of soot (m\({}^{-1}\) MPa\({}^{-1}\)) \\ \(k_{\rm h}\)\(h_{\rm h}\) & radiant attenuation factor of fly ash (m\({}^{-1}\) MPa\({}^{-1}\)) \\ \(k_{\rm K}\)\(\mu_{\rm K}\) & radiant attenuation factor of char (m\({}^{-1}\) MPa\({}^{-1}\)) \\ \(k_{\rm q}\) & radiant attenuation factor of triatomic gases (m\({}^{-1}\) MPa\({}^{-1}\)) \\ \(K\) & heat transfer coefficient of convective heating surfaces (W m\({}^{-2}\) K\({}^{-1}\)) \\ \(m_{\rm q}\) & a dimensionless coefficient correlated to the proportion of luminous area \\  & in the flame \\ \(m_{\rm r}\) & CO\({}_{2}\) annual emission reduction (t) \\ \(m_{\rm t}\) & CO\({}_{2}\) annual emission (t) \\ \(m_{\rm t0}\) & CO\({}_{2}\) annual emission under BMCR (t) \\ \(M\) & a dimensionless coefficient related to fuel characteristics, combustion \\  & mode, and temperature distribution \\ \(M_{\rm ar}\) & content of moisture on the as-received basis (\%) \\ \(M_{\rm i}\) & CO\({}_{2}\) emission intensity of power generation (g kW\({}^{-1}\) h\({}^{-1}\)) \\ \(N_{\rm ar}\) & content of nitrogen on the as-received basis (\%) \\ \(O_{\rm ar}\) & content of oxygen on the as-received basis (\%) \\ \(p\) & power generation (MW) \\ \(q_{2}\) & heat loss owing to the exhaust gas (\%) \\ \(q_{3}\) & heat loss owing to incomplete combustion of gaseous fuels (\%) \\ \(q_{4}\) & heat loss owing to incomplete combustion of solid fuels (\%) \\ \(q_{5}\) & heat loss owing to radiation and convection (\%) \\ \(q_{6}\) & heat loss owing to ash residue (\%) \\ \(Q_{\rm D}\) & available heat of fuel (kJ kg\({}^{-1}\)) \\ \(Q_{\rm tr}\) & heat transfer quantity of convective heating surfaces (W) \\ \(Q_{\rm R}\) & heat absorption of flue gas (kJ kg\({}^{-1}\)) \\ \(Q_{\rm k}\) & sensible heat of combustion air (kJ kg\({}^{-1}\)) \\ \(Q_{\rm net,ar}\) & lower heating value of mixed fuels (kJ kg\({}^{-1}\)) \\ \(Q_{\rm net,ar}^{\rm coal}\) & lower heating value of coal (kJ kg\({}^{-1}\)) \\ \(Q_{\rm net,ar}^{\rm syngs}\) & lower heating value of biomass syngas (kJ m\({}^{-3}\)) \\ \(Q_{\rm r}\) & heat entrained into the boiler envelope (kJ kg\({}^{-1}\)) \\ \(Q_{\rm av}\) & total available heat of working fluid (kW) \\ \(r_{\rm H_{\rm D}O}\) & water vapor volume fraction \\ \(S_{\rm ar}\) & content of sulfur on the as-received basis (\%) \\ \(S_{\rm ar,c}\) & converted content of sulfur (\%) \\ \(t_{\rm l}\) & acidic dew point (\({}^{\circ}\)C) \\ \(t_{\rm w}\) & water dew point (\({}^{\circ}\)C) \\ \(T_{\rm r}^{\rm w}\) & furnace exit flue-gas temperature (K) \\ \(T_{\rm a}\) & theoretical combustion temperature (K) \\ \(V^{0}\) & theoretical air volume (m\({}^{3}\) kg\({}^{-1}\)) \\ \(V_{\rm a}\) & total air flow rate of air heater inlet (m\({}^{3}\) s\({}^{-1}\)) \\ \(V_{\rm f}\) & total flue-gas flow rate of air heater outlet (m\({}^{3}\) s\({}^{-1}\)) \\ \(V_{\rm H_{\rm D}O}^{0}\) & theoretical water vapor volume (m\({}^{3}\) kg\({}^{-1}\)) \\ \(V_{\rm H_{\rm D}O}\) & total water vapor volume (m\({}^{3}\) kg\({}^{-1}\)) \\ \(V_{\rm v}\) & total flue-gas volume (m\({}^{3}\) kg\({}^{-1}\)) \\ \(V^{0}\) & theoretical flue-gas volume (m\({}^{3}\) kg\({}^{-1}\)) \\ \(V_{\rm daf}\) & content of volatile matter on a dry ash-free basis (\%) \\ \(W\) & generation capacity of the boiler (kW h) \\ \(x\) & volume of biomass syngas to 1 kg of coal under standard conditions (m\({}^{3}\) kg\({}^{-1}\)) \\ \end{tabular}