$C_1$	coefficient of the polynomial.
$C_2$	coefficient of the polynomial.
$C_3$	coefficient of the polynomial.
$C_{st}$	specific heat capacity of steam at constant pressure, kJ/(kg · °C).
$C_{su}$	specific heat capacity of sulfur at constant pressure, kJ/(kg · °C).
$F_A$	inlet flow of air, ${\mathrm{km}}^3/\mathrm{h}$.
$F_{su}$	inlet flow of sulfur, $\mathrm{t}/\mathrm{h}$.
$G_0$	total gas flow, ${\mathrm{km}}^3/\mathrm{h}$.
$G_B$	gas combustion flow of boiler, ${\mathrm{km}}^3/\mathrm{h}$.
$G_H$	gas storage flow of gas holder, ${\mathrm{km}}^3/\mathrm{h}$.
$G_L$	loss flow of gas subsystem, ${\mathrm{km}}^3/\mathrm{h}$.
$G_M$	gas conversion flow of methanol production, ${\mathrm{km}}^3/\mathrm{h}$.
$G_R$	recycled gas flow of coke oven, ${\mathrm{km}}^3/\mathrm{h}$.
$H_S$	enthalpy value of steam, kJ/kg.
$H_{FW}$	enthalpy value of feed water, kJ/kg.
$M_s$	molar mass of inlet gas of s-th syngas compressor, $\mathrm{g}/\mathrm{mol}$.
$P_{C,i,s}$	air inlet pressure of s-th compressor, $\mathrm{MPa}$.
$P_{C,o,s}$	air outlet pressure of s-th compressor, $\mathrm{MPa}$.
$P_{SC,i,s}$	inlet pressure of s-th syngas compressor, $\mathrm{MPa}$.
$P_{SC,o,s}$	outlet pressure of s-th syngas compressor, $\mathrm{MPa}$.
$P_{T1,o}$	steam outlet pressure of air separation turbine, $\mathrm{MPa}$.
$P_{T2,o}$	steam outlet pressure of syngas compressor tubine, $\mathrm{MPa}$.
$P_{st,i}$	inlet pressure of steam, $\mathrm{MPa}$.
$Q_B$	total heat value of fuel, $\mathrm{kJ}/{\mathrm{m}}^3$.
$Q_{st}$	heat released from steam, kJ/h.
$Q_{su}$	heat of sulfur absorption, kJ/h.
R	gas constant for air, $\mathrm{kJ}/\mathrm{kg}·\mathrm{K}$.
$R_u$	universal gas constant, $\mathrm{kJ}/\mathrm{kg}·\mathrm{K}$.
$S_B$	steam generation flow from boiler, $\mathrm{t}/\mathrm{h}$.
$S_D$	steam consumption flow for desulfurization, $\mathrm{t}/\mathrm{h}$.
$S_L$	loss flow of steam subsystem, $\mathrm{t}/\mathrm{h}$.
$S_T$	steam extraction flow from turbine, $\mathrm{t}/\mathrm{h}$.
$S_{AS}$	steam consumption flow for air separation, $\mathrm{t}/\mathrm{h}$.
$S_{SC}$	steam consumption flow for syngas compressor, $\mathrm{t}/\mathrm{h}$.
$T_{C,i,s}$	air inlet temperature of s-th compressor, °C.
$T_{CA}$	cold air temperature, °C.
$T_{EG}$	exhaust gas temperature, °C.
$T_{SC,i,s}$	inlet temperature of s-th syngas compressor, °C.
$T_{SC,o,s}$	outlet temperature of s-th syngas compressor, °C.
$T_{T1,o}$	exhaust temperature of air separation turbine, °C.
$T_{st,i}$	inlet temperature of steam, °C.
$T_{st,o}$	outlet temperature of steam, °C.
$T_{su,i}$	inlet temperature of sulfur, °C.
$T_{su,o}$	outlet temperature of sulfur, °C
$V_H$	volume of gas holder, ${\mathrm{km}}^3$.
$W_{C,s}$	power consumption of s-th compressor, MW.
$W_{SC,s}$	power consumption of s-th syngas compressor, MW.
$W_{T1}$	power output of air separation turbine, MW.
$W_{T2}$	power output of syngas compressor turbine, MW.
$X_A$	molar fraction of air, %.
$X_N$	molar fraction of nitrogen, %.
$X_O$	molar fraction of oxygen, %.
${\alpha }_{EG}$	excess air coefficient for exhaust gas.
${\eta }_{I,s}$	isentropic efficiency of s-th compressor, %.
${\eta }_{P,s}$	polytropic efficiency of s-th syngas compressor, %.
${\eta }_{T1}$	isentropic efficiency of air separation turbine, %.
${\eta }_{T2}$	isentropic efficiency of syngas compressor turbine, %.
${\rho }_{A,s}$	relative density of inlet air of s-th compressor.
${\rho }_{SC,s}$	relative density of inlet gas of s-th syngas compressor.
$k_{B,1}$	calculation coefficient.
$k_{B,2}$	calculation coefficient.
$k_{T1}$	adiabatic index of steam of air separation turbine.
$k_{T2}$	adiabatic index of steam of syngas compressor tubine.
$m_s$	polytropic index of s-th syngas compressor.
$q_1$	effective utilization rate of boiler, %.
$q_2$	exhaust loss of boiler, %.
$q_3$	heat loss due to incomplete combustion of gases, %.
$q_4$	heat loss due to incomplete combustion of solid fuels, %.
$r_O$	oxygen to gas $G_M$ flow rate ratio.
$r_R$	recycled gas to total gas $G_0$ flow rate ratio.
$r_f$	fresh gas to gas $G_M$ flow rate ratio.