On dynamic modeling of industrial gas turbines based on low calorific value (LCV) gaseous fuels

Abstract

Global energy demand is expected to increase in the following two decades. Operational flexibility of power generation systems is a key aspect when assessing potential solutions seeking to help meeting this expected increase in global energy demand. In low calorific value (LCV) gaseous fuels-fired power plants, it is paramount to consider the effects of the employed LCV/lean-gases-based fuels on the associated gas turbine systems and surrounding equipment. Moreover, because of the industrial processes usually occurring upstream these power plants, the fuel supply conditions change significantly during their normal operation. Gas turbines based on LCV gaseous fuels thus present a quite distinct engine behavior, and their modeling is therefore challenging. The dynamic modeling of such engines is the main focus of this work. Accordingly, the gas turbine dynamic model developed here is initially discussed, along with topics, such as gas turbine mass flow rates, cooling systems effectiveness and gas turbine component characteristics, relevant to the dynamic modeling of LCV fuels-based power plants. The use of the developed model for the simulation of an actual combined cycle power plant with cogeneration based on a LCV fuel is next highlighted. The main results show that overall acceptable agreements between computed parameters and actual power plant operating data are obtained. The corresponding average discrepancies range from 1 to 6%. In spite of the large number of factors directly influencing the numerical results obtained from the real-time simulations carried out, the power plant operating data trends are in general well reproduced by the computed results. The obtained results highlight in particular both the model applicability to operating scenarios presenting significant gradients in gas turbine characteristic parameters, and the need of including in the modeling key processes present in power plants actual operation. Keywords Power plants • Gas turbines • Low calorific value gaseous fuels • Dynamic modeling List of symbols Variables A Area (m 2) a Characteristic parameter, constant (−) b Characteristic parameter, constant (−) Cp Specific heat at constant pressure (kJ/kg K) c Characteristic parameter, constant (−) h Specific enthalpy (kJ/kg) ℏ Heat transfer (film) coefficient (kW/m 2 K) I Inertia moment (kg m 2) k Characteristic parameter, constant (−) M Mass (kg) m Mass flow rate (kg/s) N Rotational speed (rad/s) N * Non-dimensional speed (−) PR Pressure ratio (−) p Pressure (kPa) Q Heat rate (kW) T Temperature (K)

Inhomogeneous packed bed burner for improving the utilization of low‐concentration methane

“…The utilization of low‐calorific gas (LCG) contributed to energy saving and environmental protection. The common sources of the LCG included the blast furnace gas, landfill gas, and coal mine methane (CMM) 1–4 . Due to the main component of methane, the greenhouse effect of the LCG discharging was at least 21 times higher than that of carbon dioxide 5–7 .…”

“…The common sources of the LCG included the blast furnace gas, landfill gas, and coal mine methane (CMM). [1][2][3][4] Due to the main component of methane, the greenhouse effect of the LCG discharging was at least 21 times higher than that of carbon dioxide. [5][6][7] In China, the total amount of CMM drainage was about 24 billion m 3 in 2020, but only 16 billion m 3 was utilized due to large proportion of low-concentration methane.…”