Steam Injected Gas Turbine Research Articles

Study on Multivariable Dynamic Matrix Control for a Novel Solar Hybrid STIGT System

To construct a clean and efficient energy system, advanced solar thermal power generation technology is developed, i.e., a solar hybrid STIGT (Steam Injected Gas Turbine) system with near zero water supply. Such a system is conducive to the efficient use of solar energy and water resources, and to improvement of the performance of the overall system. Given that the strong correlation between multiple-input and multiple-output of the new system, the MDMC (Multivariable Dynamic Matrix Control) method is proposed as an alternative to a PID (Proportional-Integral-Derivative) controller to meet requirements in achieving better control characteristics for a complex power system. First, based on MATLAB/Simulink, a dynamic model of the novel system is established. Then it is validated by both experimental and literature data, yielding an error no more than 5%. Subsequently, simulation results demonstrate that the overshoot of output power on MDMC is 1.2%, lower than the 3.4% observed with the PID controller. This improvement in stability, along with a reduction in settling time and peak time by over 50%, highlights the excellent potential of the MDMC in controlling overshoot and settling time in the novel system, while providing enhanced stability, rapidity, and accuracy in the regulation and control of distribution networks.

Parameter evaluation for a hybrid marine system combining solid oxide fuel cells and overexpanded steam-injected gas turbine

The article focuses on the development of decarbonized marine power systems, consisting of solid oxide fuel cells (SOFC) and gas turbines (GT), aiming to provide high economic and environmental performance. Currently, the potential of such systems is not fully realized due to issues related to the insufficient reliability and durability of the fuel cells themselves, as well as suboptimal heat utilization processes in the gas turbine section of the power plant. In contrast to previous research, this study demonstrates the prospects of using the steam-injected gas turbine (STIG) cycle and overexpanded turbine to improve the heat recovery conditions of exhaust gasses from fuel cells, enhance the efficiency of the power system, and increase the longevity of its key components. To achieve this, a corresponding mathematical model was developed, and optimization calculations for the proposed system cycle were conducted. Adopting the proposed cycle with a steam-injected gas turbine resulted in a 4.4 % increase in efficiency compared to traditional schemes. Such a system could be utilized in the design of advanced marine power system for the next generation.

Use of high salinity water in a power plant by connecting a direct contact membrane distillation (DCMD) to a steam-injected gas turbine (STIG)

Unlike steam turbines, electricity production in gas turbines is inherently independent of freshwater consumption. However, the thermal efficiency of gas turbines decreases as the temperature of input air increases. As a result, many methods of cooling the inlet air require the use of fresh water. Moreover, when it comes to humid gas turbine technology, the practice of injecting steam or humid air into the turbine to improve its thermal efficiency and output power consumes a substantial amount of freshwater. Therefore, reducing the use of fresh water to enhance the output power and thermal efficiency of gas turbines can be a necessary option, especially in hot and dry regions. Alternatively, considering the significant amounts of waste heat in gas turbines, one solution to reduce fresh water consumption is to connect them to thermal desalination units. However, conventional thermal desalination is only practical for seawater desalination in coastal areas. Therefore, this study explores the possibility of linking a direct contact membrane distillation (DCMD) unit to a Steam-injected gas turbine (STIG), which can use high salinity water sources like reverse osmosis (RO) brine in inland regions. The freshwater generated by the DCMD is used to chill the input air to the compressor and produce steam injected within the turbine. Simulation results show that this connection can raise the net output power by [9 to 17.2] MW and thermal efficiency by [3.3 to 15.6] % for compressor pressure ratios between [5 to 30], when compared to a simple gas turbine.

Potential evaluation of integrated high temperature heat pumps: A review of recent advances

Industrial and high temperature pumps are a well-established, sustainable, and low-emission technology for processing temperatures below 100 °C, especially when driven by renewable energy. The next frontier in heat pumping is to enhance the economic working envelope to serve the 100–200 °C range, where an estimated 27% of industrial process heat demand is required. High temperature heat pumps (HTHP) are an effective technology for delivering heat and recovering waste heat from various industrial processes, hence reducing primary energy consumption and the resulting CO2 emissions. The integration of high temperature heat pumps into different industrial process networks provides significant environmental and performance improvements,an innovative and profitable solution for different decarbonizing sectors. Higher temperature heat pumps offer significant potential to enhance thermally demanding industrial processes due to their high temperature lift capability. This review looks at how future improvements in HTHP technology can take use of breakthroughs in high-temperature heat pump research to address important technical obstacles. This review primarily consolidates data from HTHPs integrated with various industrial processes applications such as thermal energy storage, low-grade waste heat recovery, membrane fuel cell, organic Rankine cycle, super-critical water desalination, co-generation and poly-generation, vapor injection, steam injected gas turbine, and solar absorption system. However, the widespread diffusion of HP technologies faces several challenges, including technological (limitation of the electrical network due to intensive electrification of the heating sector), economic (high investment and installation cost), regulatory (lack of standards and mandatory policies), policy (uncertainty in policy and lack of clear heat decarbonization pathways and technology uptake), and public acceptance issues (unwarranted fear, misperception, misinformation, and previous experiences on the reliability of heat pumps) are highlighted.

Using of saltwater to increase the output power of a steam injected gas turbine (STIG) by connecting spray freezing desalination to it

Gas turbines are one of the common methods for generating electrical energy. However, reducing the output power by increasing the air temperature is one of the problems of these turbines. Common methods to compensate for the power drop of gas turbines are often based on turbine inlet air cooling (TIAC) technology or injecting steam or water into the turbine as humidified gas turbine (HGT) that causes an increase in its output power. However, these technologies often require high consumption of fresh water which limits their use in dry and low-water areas. Therefore this study has investigated the connection of a spray freezing desalination to a steam-injected gas turbine (STIG) through a reverse Brayton cycle for increasing its output power by consuming saltwater. This spray freezing desalination is a process based on eutectic freeze crystallization (EFC) technology that uses compressed air in a turbo expander to produce chilled air that can crystallize the droplet of sprayed saline water. This desalination technology has the potential of zero liquid discharge (ZLD). Therefore, with the possibility of using a saline water source such as reverse osmosis (RO) brine in this process, in addition to increasing the output power of gas turbines, it will be possible to reduce the environmental problems related to its disposal.

Performance Evaluation of Solar-assisted Trigeneration System in Thermo-environmental Perspective

Nowadays, the trigeneration systems are proving more promising than a combined cycle system. In terms of efficiency and reliability, these systems meet the typical requirements of cooling heating power in various applications. This work investigated the thermodynamic and environmental characteristics of a solar-based tri-generation system. The studied system consists of gas turbine and steam turbine modules along with heating and cooling provisions as per demand. The integrated system using parabolic trough collectors and also uses steam injected gas turbines for performance improvement. The overall performance of the proposed work is compared with and without a steam injection. The effect of integration of the solar cycle and steam injection for the trigeneration system is assessed. Further, carbon footprint rejected to the environment is also estimated. It is observed that the work output and trigeneration efficiency improved, and the carbon footprint gets reduced in the range varying between 10–40% for the cases studied.

Connection a vapor jet refrigeration system to a steam injected gas turbine

One of the problems with the gas turbine is the reduction of output power and thermal efficiency with an increase in the ambient temperature. This problem is serious, especially in hot and dry areas. To solve this problem, in this study, the connection of the steam jet refrigeration (VJRS) unit to a gas turbine is investigated. By designing a VJRS as an open cycle in this connection, in addition to cooling the inlet air, it is also possible to inject steam into the turbine as a steam-injected gas turbine (STIG) system. So in this process reducing the compressor power consumption and increasing the turbine output power are done simultaneously. With the possibility of injecting most of the steam into the turbine, in addition to the possibility of removing the condenser in the VJRS, the need for cooling water is also eliminated in this process. Therefore, by using a saltwater source to generate steam using the waste heat of the gas turbine, it is possible to increase its output power without the consumption of fresh water. Also compared to a combined cycle, is shown the ability of this process to increase the output power without needing to install additional expensive equipment.

Thermochemical recuperation by steam methane reforming as an efficient alternative to steam injection in the gas turbines

Improving the energy efficiency of gas turbines is an extremely important task of the world energy industry. This paper presents the results of thermodynamic analysis of a gas turbine unit with thermochemical exhaust heat recuperation by steam methane reforming (chemically recuperated gas turbine — CRGT). The thermochemical exhaust heat recuperation systems consist of a reformer, a steam–methane mixture preheater, and a steam generator. The main goal of this paper is comparing CRGT efficiency with the efficiency of a gas turbine unit with steam injection (STIG). To calculate the recuperated heat in a reformer, the thermodynamic analysis of steam methane reforming was performed via Gibbs free energy minimization method. Both thermodynamic cycle and reforming analysis were performed via Aspen HYSYS. The analysis was performed in the temperature range of working fluid at a turbine inlet (Tin) of 800–1300 °C and the steam-to-methane ratio of 1, 2, 3 (mol-to-mol). The results showed that thermochemical exhaust heat recuperation can be considered as an alternative to steam injection in gas turbines. The efficiency of CRGT is higher than the efficiency of STIG for the same steam-to-methane ratio. With increasing in Tin the efficiency of CRGT is increasing. The efficiency of STIG and CRGT at Tin=1300 °C for a steam-to-methane ratio of 3 is 37.4% and 47.3%, respectively.

Thermodynamic performance study of a new diesel-fueled CLHG/SOFC/STIG cogeneration system with CO2 recovery

A new type of diesel-fueled cogeneration system is proposed in this study. The system mainly includes solid oxide fuel cell, chemical looping hydrogen generation and steam injection gas turbine cycle. The system can effectively avoid the carbon deposition of solid oxide fuel cell, recovering CO2 without separation energy consumption. Additionally, it adopts the way of centralized supply of steam and air, thus reducing the complexity and loss of the system. On this basis, the system is comprehensively evaluated by sensitivity analysis, exergy analysis, energy utilization diagram analysis and exergoeconomic analysis. It is found that the total power efficiency, exergy efficiency and fuel energy saving ratio of the new system can reach 64%, 60% and 60% respectively. Meanwhile, the power production cost of the new system is 51.25 $/GJ, and the optimization suggestion of the system is given according to the result of exergoconomic analysis. The proposed system provides a theoretical basis and new idea for the design and construction of diesel-fueled energy supply system.

Parametric analysis of the efficiency of the combined gas-steam turbine unit of a hybrid cycle for the FPSO vessel

Abstract A thermal diagram of the combined gas-steam turbine unit of a hybrid cycle, which is an energy complex consisting of a base gas turbine engine with a steam turbine heat recovery circuit and a steam-injected gas turbine operating with overexpansion, is proposed. A mathematical model of a power plant has been developed, taking into consideration the features of thermodynamic processes of simple, binary, and steam-injected gas–steam cycles. Thermodynamic investigations and optimization of the parameters of a combined installation of a hybrid cycle for the generation of electrical energy have been carried out. Three-dimensional calculations of the combustion chamber of a steam-injected gas turbine were carried out, which confirmed the low emissions of the main toxic components.

Water and steam injection in micro gas turbine supplied by hydrogen enriched fuels: Numerical investigation and performance analysis

This paper investigates the energetic and environmental performance of micro gas turbine plant with two proposed concurrent improvements: the methane-based fuel enriched by hydrogen and the humidification of the plant cycle. The energetic and environmental benefits of both features are well-know, and the aim of this work is the analysis of their combined impact on the micro gas turbine operation. Despite enhancing fuel with H2 involves significant advantages like greenhouse emission reduction and a better combustion in case of low LHV fuels, most of commercial micro gas turbine combustors are not able to burn fuels with high hydrogen content unless structurally modified. On the contrary, has been demonstrated that humidified gas turbines (i.e., gas turbines with water injection, humid air turbine (HAT) and steam injection gas turbine (STIG) cycles) improve the combustion stability as well as electric power delivered and plant efficiency. Hence, in order to investigate the feasibility of the concurrent two features, the first step of this work was the thermodynamic analysis of a micro gas turbine supplied by methane-based fuels enriched with H2 up to 20%vol, considering both dry and humidified cycles. Since a combustion anomaly was detected, i.e., flashback, in the CFD study on the combustion chamber, a steam injection in the combustor has been added in the plant layout with the aim of overcoming the anomaly, and its effect on the combustion process has been analyzed also raising the hydrogen content up to 30%vol. The main outcome of this paper is the assessment of the feasibility of supplying the combustor of the proposed HGT-STIG micro gas turbine with a hydrogen enrichment up to 30%vol, achieving a safe and regular combustion mainly owing to a steam injection mass flow equal up to 125% of fuel flow.

Advanced Exergy and Exergoeconomic Analysis of a Gas Power System with Steam Injection and Air Cooling with a Compression Refrigeration Machine

Gas turbine power plants have been widely studied, and as a result the negative effects on their output power and thermal efficiency have been known when operating in atmospheric conditions exceeding ISO conditions. For this reason, different technologies and methodologies have been implemented, aiming to increase the output power and improve the thermal efficiency. Unfortunately, the lack of operational parameters for this system limited its characterization and implementation of strategies to improve its performance. Advanced exergetic and exergoeconomic analyses have been applied to improve energy and economic performance in steam injection gas turbine (STIG) cycle power plants with air cooling with a compression refrigeration machine. Results shows that the main sources of irreversibilities and higher costs are in the Combustion Chamber (CC), Heat Recovery Steam Generator (HRSG) and Gas Turbine (GT). From these components, the components of the HRSG and GT have the greatest potential for improvement, and this can be achieved by improving the overall configuration of the system, due to the fact that the destruction of exogenous exergy is in more significant measure avoidable. While the higher costs of investment can be reduced in the Combustion Chamber and Gas Turbine.

Efficiency Boosting and Steam Saving for a Steam-Injected Gas Turbine Engine: Optimization Study of the Running Conditions

AbstractThe increasing demand for gas turbines motivates the need to improve their performance and reduce the associated exhaust pollutants. Steam injection is an effective technique for boosting p...

A Review On Secondary Fluid Injection In Turbomachines

A turbomachine is basically a rotating blade or a set of rotating blades which in some cases utilizes the energy of the working fluid and in other cases imparts energy to it. Turbomachines are mainly divided into three ways i.e. on the basis of velocity vector of incoming flow (Axial, radial and mixed), on the basis of amount of fluid flow (open and closed), on the basis of utilize the energy (power consuming and power producing). There we will discuss on the third part of turbomachines i.e. on the basis of power consuming or power producing. A turbomachine works on either a high energy fluid or low energy fluid which is known as the primary fluid. Through the years many developments have been made to increase the efficiency of the machines to keep pace with the increasing population and the development of new technologies. In many Turbomachines these requirements are met by introduction of a secondary fluid at specific places or parts of the turbomachine. The secondary fluid can be different from the primary fluid or it can be the same also. There are many methods which utilize the properties of the secondary fluid to increase the performance of the turbomachine. Some methods are in widespread use while others are might be used in future. Some of the examples of methods of injecting secondary fluid are: water injection in jet engines to suppress noise and thus decrease the vibroacoustic stresses. Film cooling technique which injects cold air or steam on gas turbine parts to increase their working life which allows higher firing temperatures and thus increases efficiency. In compressors water is used to increase humidity which helps to increase the efficiency of a hydrogen cell. Apart from all these examples there are so many other applications of fluid injection in turbomachines which are like Air in hydro machines, Air in gas turbines, Air in pumps, Air in marine hydrokinetic turbine, Steam injection in gas turbines, Water injection in jet engines.

Solar hybrid steam-injected gas turbine system with novel heat and water recovery

For concentrating solar power, Brayton cycle offers a more attractive method than Rankine cycle to improve the flexibility and the efficiency of electricity production and peak-load regulation. Therefore, in this study, a solar hybrid steam-injected gas turbine system with novel heat and water recovery is proposed. The new system injects steam at the inlet of a turbine and recovers waste heat and water from exhaust gas. Thermodynamic models of the novel system are built to analyze main factors that affect the performance and characteristics. The system efficiency is improved by 17% under an optimal steam injection rate of 0.065. Water recovery rates reach up to 98%, which is associated with a high waste heat recovery rate from the exhaust gas. Compared with a single-stage absorption refrigeration unit, the heat recovery rate and refrigeration capacity of the system with a double-stage absorption refrigeration unit are increased by 109% and 63%, respectively. Furthermore, the models are applied to analyze the annual performance and environmental sustainability of the novel system in Lhasa and Dunhuang, western China. The maximum efficiency and peak power output of the novel system are increased by 21.8% and 37.9%, respectively. The consumption of fuels and emissions of CO2 is lower than conventional gas turbine. These results indicate that the proposed system shows high efficiency possibility and environmental sustainability with a near-zero water consumption.

A Parametric Investigation of the Steam Injection Gas Turbine System on a Cogeneration Plant

A Parametric Investigation of the Steam Injection Gas Turbine System on a Cogeneration Plant

Environmental impact and cost analysis of gas turbine cycles with steam injection and inter-stage turbine reheat

Inter-stage turbine reheat is an effective gas turbine retrofit which can easily be used with simple and steam injected gas turbines as well. Owing to the uncertainties relating to an efficiency comparison of steam injected and no-injection cycle designs, thermoeconomics and environmental impacts have been considered to evaluate reheat and steam injection which regards pollutant emissions and environmental costs together. Being the complemental of the authors previous studies on steam injected gas turbines, simple, reheat, steam injected (STIG) and reheat steam injected (RHSTIG) gas turbine cycles are compared. Economic feasibility of steam injection as well as inter-stage turbine reheat are discussed according to 2018 plant cost data. Optimal cycle parameters are determined using a new comprehensive cycle model which permits to work with realistic working fluids, simulates the combustion process regarding 14 exhaust species and determines NOx and CO emissions.

Environmental impact and cost analysis of gas turbine cycles with steam injection and inter-stage turbine reheat

Inter-stage turbine reheat is an effective gas turbine retrofit which can easily be used with simple and steam injected gas turbines as well. Owing to the uncertainties relating to an efficiency comparison of steam injected and no-injection cycle designs, thermoeconomics and environmental impacts have been considered to evaluate reheat and steam injection which regards pollutant emissions and environmental costs together. Being the complemental of the authors previous studies on steam injected gas turbines, simple, reheat, steam injected (STIG) and reheat steam injected (RHSTIG) gas turbine cycles are compared. Economic feasibility of steam injection as well as inter-stage turbine reheat are discussed according to 2018 plant cost data. Optimal cycle parameters are determined using a new comprehensive cycle model which permits to work with realistic working fluids, simulates the combustion process regarding 14 exhaust species and determines NOx and CO emissions.

High temperature heat and water recovery in steam injected gas turbines using an open absorption heat pump

The advantages of reinjecting steam from the heat recovery steam generator (HRSG) in the preceding gas turbine are increased power and electrical efficiency at low specific cost and a high operating flexibility. The discharge of the injected steam to the ambient has however two major drawbacks: (1) a relevant water consumption and (2) a large thermal loss related to the latent heat of steam. An open absorption heat pump cycle downstream of the HRSG can solve both problems, as it allows to recover the steam from the flue gas and use its condensation heat at elevated temperature. This paper presents for the first time a concept to efficiently integrate both technologies and assesses the potential and limitations of the absorption system for a steam injected gas turbine. For high network return temperatures (60 °C), the “High Temperature Condensation Boiler Technology” (HT-CBT) performs significantly better than a conventional flue gas condenser over the entire STIG operating range, both with respect to fuel efficiency and water recovery. For steam injection rates up to 1.16 kg/s (60 °C) and 0.96 kg/s (40 °C) fuel efficiency remains constant at ca. 95% resp. 102% and power can hence be increased without the associated energetic penalty. Within this range, full water recovery eliminates the high water usage of the Cheng Cycle, making it a suited technology for flexible cogeneration also in dry areas. For higher steam injection rates, the added benefit of the HT-CBT was found to be restricted by the limited availability of desorber heating from the HRSG, suggesting the integration of external desorber heating. The possibility to increase the power output for a given heat demand, with limited impact on fuel efficiency, increases the economic viability of the technology compared to heating only applications.

Steam injected Humphrey cycle for gas turbines with pressure gain combustion

Gas turbines are a mature technology and any increase in their efficiency comes at high R&D cost. Pressure Gain Combustion (PGC) has emerged as a concept to significantly improve their efficiency. Technically, PGC is realized through detonative combustion or approximations of constant volume combustion. The latter include pulsed resonant combustion and shockless explosion combustion. Detonation combustion is typically realized as pulsed or rotating detonation combustion. Gas turbine processes with PGC are modeled with the Humphrey or the ZND cycle. Most thermodynamic studies focus on the basic gas turbine cycle with PGC. The current work extends this scope by presenting a thermodynamic analysis of the steam injected Humphrey cycle. Steam injected gas turbines have several advantages that complement these of PGC. Steam injection can reduce NOx emissions and can be used in PGC gas turbine cycles to maximize combustor pressure gain. The present work applies 0-D thermodynamic modeling to compare the thermal efficiency of the Humphrey-STIG cycle to that of the Joule-STIG cycle. An optimum method to realize heat recuperation through steam injection in a Humphrey cycle is defined. The work concludes by defining Humphrey-STIG cycle configuration that result in realistic lengths of shockless explosion combustors.