Intercooled Recuperated Gas Turbine Research Articles

Thermo-economics, emissions, and sustainability comparison of a novel hybrid evaporative cooled solid oxide fuel cell-recuperated gas turbine with conventional system

A novel integration of a solid-oxide fuel cell to an evaporative intercooled recuperated gas turbine (SOFC-EIc-RGT) is presented. The goal of this integrated system is to reduce power consumption associated with the work of compression and hence augment power plant performance. The proposed system is compared with a conventional evaporative intercooled recuperated gas turbine (EIc-RGT). Both energetic and exergetic performance of the systems were carried out. A range of sustainability indexes were evaluated for each component of both configurations. The sustainability index helps to identify the impact on the environment. A novel entropy generation number, a dimensionless number, was proposed to identify “the ratio of component’s irreversibility to the heat supplied.” The maximum energy and exergy efficiencies for SOFC-EIc-RGT were nearly double that of the EIc-RGT. A novel performance map and emission map were plotted for power plant design engineers and researchers to analyse CO and NOx emissions with various operating parameters for EIc-RGT and SOFC-EIc-RGT. This economic analysis makes the system more reliable, which includes environmental and fuel cost rates.

Design and sensitivity analysis of a multistage solid oxide fuel cell hybrid system with an inter-cooled-recuperated gas turbine and organic Rankine cycle

A solid oxide fuel cell (SOFC) hybrid system with an inter-cooled-recuperated gas turbine(ICRGT) and organic Rankine cycle (ORC) was designed to address exergy destruction in the burner of a conventional SOFC and gas turbine (GT) system. In unfired mode of this system, SOFC acts as the GT heater and reheater instead of burners; burners are used only to aid load regulation in fired mode. In unfired mode, the system electrical efficiency is 69.86 % and the overall efficiency is 82.22 %. The total exergy destruction of the system is 21.93 % lower than that in fired mode by exergy analysis, which indicates the effectiveness of reducing afterburner exergy destruction, and the superior energy efficiency of this mode. For the design analysis, we analyzed the influence of different factors on the system, including the number of SOFC modules, turbine outlet temperature, burner exhaust into the turbine, oxidant utilization of SOFC cathode(OUC), and fuel utilization of SOFC anode(FUA) on the system. For the sensitivity analysis, we determined the variation rules of the components and system parameters for fuel proportions of 70–105 %. This work provides a reference for optimizing the design and operation of SOFC-GT and other SOFC hybrid systems.

Estimation of exergy-based sustainability index and performance evaluation of a novel intercooled hybrid gas turbine system

This paper contributes a novel sustainability index and modified exergy indicators for conventional gas turbines and solid oxide fuel cell integrated gas turbine (SOFC-GT) hybrid power cycles. In this work, an intercooled gas turbine (Ic-GT) cycle is considered as a base cycle, which gives an additive advantage in lowering the power required for the compressor. Moreover, on SOFC integration with Ic-GT, the qualitative and quantitative performance are examined. Numerical modeling is done using MATLAB and an exclusive comparison has been made based on energy-exergy and sustainability analysis for the system and its components. On comparing the first law efficiency at turbine inlet temperature, TIT 1250K and rp = 18 for Ic-GT, intercooled recuperated gas turbine (Ic-RGT), and Ic–SOFC–RGT, it is 25.82%, 36.04%, and 64.78%, respectively. Similarly, second law efficiency is 11.43%, 22.33%, and 61.11% and the overall sustainability index is 1.12, 1.28, and 2.57 for Ic-GT, Ic-RGT, and Ic–SOFC–RGT, respectively. Nine other modified exergy-based parameters are used to identify the role of fuel and product exergy and then compare the most affected component in three configurations.

Thermoeconomic investigation of power utilities: Intercooled recuperated gas turbine cycle featuring cooled turbine blades

In the era of fast paced development, energy sector is also looking for methodologies which can diligently investigate the thermodynamics as well as economics of power utilities. The methodology need to be so designed that it is able to analyze the effect of operating parameters on plant performance and its costing. In this regard thermoeconomic investigation is a tool which combined thermodynamic concepts and economic principles to analyze thermal systems. Present paper deals with comparative thermoeconomic investigation of basic gas turbine (BGT) and intercooled recuperated gas turbine (IcRcGT) cycle based power utilities featuring air film cooling of turbine blades. The work also represents the effect of operating parameters on thermoeconomics of two aforesaid cycles. In present work Average-Cost-Theory approach has been adopted for the investigation. The results so obtained from calculation reports that IcRcGT offers 50% higher plant specific work with 27.8% higher fuel flow rate as compared to BGT for base case parameters (rpc = 30, TIT = 1500 K, ηAC = 88% and ηGT = 90%). The total cost rate for IcRcGT is 16.33% higher and at the same time related cost of electricity is 20% lower as compared to BGT for same operating parameters due to higher plant specific work.

Thermodynamic assessment of SOFC-ICGT hybrid cycle: Energy analysis and entropy generation minimization

Hybrid power systems are being developed by the integration of fuel cell with conventional gas turbine. Integration of solid oxide fuel cell (SOFC) with gas turbine (GT) to form a hybrid cycle based power plant has been considered as this is known to be highly efficient primarily performance of SOFC being not limited to Carnot efficiency. In this article, a novel and optimal thermal integration of SOFC with intercooled-recuperated gas turbine has been presented. The novel contribution of this work is integration of blade cooled gas turbine model to a SOFC model. 1st and 2nd law thermodynamic analysis has been performed analyzing the influence of compression ratio (rp,c) and turbine inlet temperature (TIT) on hybrid plant specific work, hybrid efficiency, blade coolant requirement and entropy generation rate. The performance of hybrid system has been optimized by entropy generation minimization, for this purpose a constraint based algorithm has been developed, which is a function of recirculation ratio, mass of fuel and TIT, based on which gas composition at the anode exit stream has been examined. It has observed that the entropy generation first increases and then decreases as TIT increases. Furthermore, a unique performance contour has also been plotted for proposed hybrid cycle, which can be utilized by power plant designer. At TIT 1800K and rp,c 20, optimal efficiency has been achieved with entropy minimization of 8.05 W/K.

Novel and optimal integration of SOFC-ICGT hybrid cycle: Energy analysis and entropy generation minimization

Integrating fuel cells with conventional gas turbine based power plant yields higher efficiency, especially solid oxide fuel cell (SOFC) with gas turbine (GT). SOFCs are energy efficient devices, performance of which are not limited to Carnot efficiency and considered as most promising candidate for thermal integration with Brayton cycle. In this paper, a novel and optimal thermal integration of SOFC with intercooled-recuperated gas turbine has been presented. A thermodynamic model of a proposed hybrid cycle has been detailed along with a novelty of adoption of blade cooled gas turbine model. On the basis of 1st and 2nd law of thermodynamics, parametric analysis has been carried out, in which impact of turbine inlet temperature and compression ratio has been observed on various output parameters such as hybrid efficiency, hybrid plant specific work, mass of blade coolant requirement and entropy generation rate. For optimizing the system performance, entropy minimization has been carried out, for which a constraint based algorithm has been developed. The result shows that entropy generation of a proposed hybrid cycle first increases and then decreases, as the turbine inlet temperature of the cycle increases. Furthermore, a unique performance map has also been plotted for proposed hybrid cycle, which can be utilized by power plant designer. An optimal efficiency of 74.13% can be achieved at TIT of 1800 K and rp,c 20.

Thermodynamic optimization of a triple-shaft open intercooled-recuperated gas turbine cycle. Part 1: description and modeling

Considering the flow processes of the working fluid with the pressure drops, a thermodynamic model for a triple-shaft open intercooled-recuperated gas turbine cycle is established using thermodynamic optimization theory in Part 1 of this paper. The relative pressure drops associated with the flow through various cross-sectional areas are derived as functions of the low-pressure compressor inlet relative pressure drop. The analytical formulae of the cycle's power and efficiency are derived. The performance of the model cycle is optimized by adjusting the compressor inlet pressure, the mass flow rate and the distribution of pressure losses along the flow path in Part 2 of this paper.

Digital Control System Development for an Intercooled Recuperated Gas Turbine

The on-going development of a full authority digital engine control (FADEC) system for the US Navy’s Intercooled Recuperated (ICR) gas turbine requires a high level of system coordination to achieve the primary benefits of reduced specific fuel consumption and improved specific output power relative to a simple cycle engine. This paper describes the system requirements analysis and the implementation of control algorithms leading to the preliminary ICR control system design. The ICR control system is required to coordinate the actions of over 30 actuators using data taken from over 150 sensors. Primary control of the engine output power is provided by regulation of the fuel metering valve. Thermal management of the intercooler, recuperator, and variable area power turbine nozzle results in maximum cycle efficiency within safe operating limits. The new electronic engine controller (EEC) is based on a new open architecture Futurebus + backplane and is fully redundant in all operationally critical control functions. The EEC also features an operating panel and video display for local operation and maintenance of the control system. The graphic display and function keys provide access to control functions as well as assisting maintenance activities with built-in test diagnostics to trouble shoot failed circuitry.