Gas Turbine Power Plant Research Articles

Parametric diagnostics and assessment of the state of gas turbine power plants using SCADA-technologies and imitation mod-elling

Parametric diagnostics and assessment of the state of gas turbine power plants using SCADA-technologies and imitation mod-elling

Comparative analysis of various channel shapes for a plate-fin heat exchanger of a small-sized gas turbine power plant

Comparative analysis of various channel shapes for a plate-fin heat exchanger of a small-sized gas turbine power plant

ІНТЕГРАЛЬНА ІНФОРМАЦІЙНО-ОБЧИСЛЮВАЛЬНА СИСТЕМА, ЩО ЗАБЕЗПЕЧУЄ ТЕХНІЧНЕ ОБСЛУГОВУВАННЯ ЗА СТАНОМ СИЛОВИХ ГАЗОТУРБІННИХ УСТАНОВОК

The effectiveness of the chosen maintenance strategy is determined by the completeness of information about the current technical condition of the facility. The real current state of a dynamic object should specify the list and scope of preventive and remedial work for each specific maintenance object. Existing strategies and programs according to the technical condition of dynamic objects are conditionally divided into three groups: with control over the level of reliability of the operating object; with control of the parameters of the object of operation; hybrid. Power gas turbine plants are objects of operation with high functional significance. They have an insufficient degree of redundancy, as well as a low level of operational manufacturability. Therefore, it is advisable for them to apply a maintenance strategy as per the parameter control. The article proposes general principles on the basis of which an integral information-computing system for processing parameters can be built. This system is the main element of the automated control system for the technical condition of the gas turbine power plant. Synthesized adaptive system for dynamic control of parameters characterizing the current technical state of a gas turbine power plant. Closing the control loop of the technical condition of the object with negative feedback allows you to switch from the strategy of its maintenance according to the operating time to the maintenance strategy according to the state with the control of parameters. The integrated information-computing system should solve two main tasks: a reliable assessment of the current technical state of a dynamic object and prediction of a pre-failure state in the medium and long term. The main condition for organizing the maintenance of dynamic objects according to the state with the control of parameters is the possibility of continuous monitoring of the parameters characterizing the current technical state. The choice of such parameters is ambiguous, which is due to both the specific features of dynamic object and diverse nature of relationship between faults and controlled parameters. The requirements for the determining parameters are of a general nature: the parameters must have acceptable accuracy and stability of readings over time; have the greatest diagnostic value among other parameters; not depend on changes in external operating conditions and modes of operation; based on standard measurements. The system of continuous monitoring of parameters characterizing technical state of a dynamic object must be adaptive. It should change in accordance with the change in technical condition of the gas turbine power plant. The use of a set of parameters of its dynamic linear model as characteristic of the current technical state of an object is justified for a wide class of objects. The control system of such objects operates in the stabilization mode, therefore, the adaptive system of continuous monitoring synthesized on the basis of this model provides the possibility of assessing the current technical state of the gas turbine power plant and makes it possible to predict its technical state. At the same time, the adaptation of the parameters of the linear dynamic model of the object to the new technical condition of the gas turbine plant should be carried out with the least interference in the normal operation of the plant.

Development and assessment of a low-emissions gas turbine system for power utilities incorporating intercooling and solar preheating

• 1. Two novel solar-hybrid gas turbines with high compression ratios are proposed. • 2. The novel cycles use PTCs to preheat the compressed air before their combustors. • 3. A high solar share of 24.3% and lower CO2 emissions of 28.14 can be achieved. • 4. The novel cycles have high efficiencies and low electricity costs. • 5. The novel cycles have low fuel consumption rates with short payback periods. Literature shows that using medium-temperature solar collectors, such as parabolic trough collectors (PTCs), to heat the gas turbine's compressed air before it enters the combustion chamber is unfeasible with high-pressure ratio gas turbines. This is because the compressor's outlet air temperature exceeds the solar field's maximum operating temperature. In this study, PTCs technology was integrated into intercooled gas turbine cycles to solve this problem. Intercooling a gas turbine improves its performance and allows for solar energy integration of PTCs. Two inventive solar preheated intercooled gas turbine power plants with a high-pressure ratio of 37 have been proposed and investigated: solar preheated single-intercooled gas turbines (SP-IcGT single ) and solar preheated double-intercooled gas turbines (SP-IcGT double) . Under design and off-design operation conditions, the plants' performance and optimal solar field area were evaluated. A comprehensive economic and environmental analysis of the novel cycles was also conducted and reported. The study shows that the solar integration of PTCs with intercooled gas turbines is a promising technique, providing a fuel-based efficiency of 54% for the SP-IcGT double and 51.3% for the SP-IcGT single . In addition, the analysis shows that the novel cycles have a high solar share, save more fuel, and are more environmentally friendly than solar-preheated conventional gas turbines. SP-IcGT double saves 28.2% and SP-IcGT single saves 19.3%. The SP-IcGT double and SP-IcGT single consume 6675 and 7017 kJ/kWh, respectively, compared to 9500 kJ/kWh for solar preheated conventional gas turbines in the previous literature. Furthermore, the economic analysis shows positive prospects for solar preheated intercooled gas turbine projects. The SP-IcGT double has a payback period of 6.409 years and the SP-IcGT single has 5.545 years. Overall, the solar integration of PTCs with intercooled gas turbines is an attractive technology in Sunbelt countries.

ИССЛЕДОВАНИЕ СОВМЕСТНОЙ РАБОТЫ АВТОНОМНОЙ ГАЗОТУРБИННОЙ ЭЛЕКТРОСТАНЦИИ И ГЕНЕРИРУЮЩЕГО УЗЛА С ВОЗОБНОВЛЯЕМЫМИ ИСТОЧНИКАМИ ЭЛЕКТРОЭНЕРГИИ

The relevance The installed capacity of renewable energy sources increases annually relative to the total installed capacity. Features of work inherent in renewable energy installations modify the nature of transient processes in electric power systems during emergency modes. A number of authors, when studying the operation of renewable sources as part of the energy system, consider the parallel operation of renewable sources with a powerful electric power system, and also do not take into account the drive motors of power plant generators. In this paper, the study of transient processes is carried out in an isolated electric power system with renewable energy sources, the power of which is comparable to the power of classical generators. This work is dedicated to the study of transient processes in an isolated electric power system with renewable energy sources, the power of which is comparable to the power of classical generators. The research takes into account the model of a synchronous generator drive motor and its control system, configured in accordance with applicable requirements and standards. Aim of research The main aim of the research is to assess the impact of renewable energy sources on the operating modes of an isolated gas turbine power plant during emergency disturbances. Research methods To achieve the main aim of the research the method of the simulation mathematical modeling in Matlab/Simulink was used. Results During the research, a number of curves were obtained that characterize the operating modes of an isolated power system during an emergency process. The analysis of these curves has showed that the stable operation of the power plant is possible with the installed capacity of renewable energy sources not exceeding 60 % of the power reserve of the power plant's lead generator.

Thermo-economic assessment of upgrading a basic gas turbine power plant into CHP plant

Thermo-economic assessment of upgrading a basic gas turbine power plant into CHP plant

Exergoeconomic and sensitivity analyses of a gas turbine power plant using MINI-REFPROP and MATLAB simulink

In this paper, exergy, exergoeconomic, and exergoenvironmental analysis of a gas turbine cycle and its optimization have been carried out by MINI-Reference Fluid Properties (MINI-REFPROP) and Matrix Laboratory (MATLAB) SIMULINK. The parametric study was carried out based on the Specific Exergy Costing approach. The mathematical models were developed and presented regarding mass, energy, and economy. The Excel and MATLAB LIBRARY TOOLS BOX are used to perform thermodynamic properties and research analyses. The analyses lead to valuable economic status benchmarks. The exergoeconomic factor, relative cost, total cost of energy loss, and energy destruction for the combustion chamber and work output were determined. The parametric study was conducted, considering the effects of the gas turbine inlet temperature, air compressor inlet temperature, and compressor pressure ratio. For the considered case study status, the combustion chamber in the plant revealed the highest amount of energy destruction (85%), leading to the recommendation that more attention be paid to boilers in terms of design, selection, operation, and maintenance, while the combustion chamber has a high improvement potential (91%).

Numerical and Experimental Study of Combustion of Methane-Hydrogen Mixtures in a Model Combustion Chamber of a Gas-Turbine Power Plant

Numerical and Experimental Study of Combustion of Methane-Hydrogen Mixtures in a Model Combustion Chamber of a Gas-Turbine Power Plant

The investigation of an SGT5-2000E gas turbine power plant performance in Benin City based on energy analysis

• The effect of change in ambient air temperature on the performance of the SGT5 -2000E Gas turbine Power Plant was analyzed for this location. • The average net power output was 97.33% of the guaranteed value. • For this location, a 1 0 C rise in ambient air temperature, there are drops of 1.16% in net power output and 1.58% net thermal efficiency, a 1.58% increase in SFC and HR, and a 0.64% decrease in WR. • This study has suggested efficient ways of overcome drawbacks observed. In order to address the growing global energy demand and save energy from operating gas turbine power plants, the performance and losses from existing gas turbine power plants need to be studied. In view of this, this research work aims at carrying out the energy analysis of the SGT5-2000E Gas Power Plant for off-design conditions. The energy analysis was conducted using operating data collected from the power plant to evaluate the thermal efficiencies, specific fuel consumption (SFC), heat rate (HR), work ratio (WR) and energy losses with the aid of MATLAB software. The effects of ambient air temperature and compressor pressure ratio on the thermodynamic performance were carried out. Energy analysis results obtained showed that the average net thermal efficiency of the SGT5-2000E Gas Power Plant was found to be 30.21% at the ambient air temperature range from 21 to 35 0 C, the compressor pressure ratio of 10.73 to 10.96, the net power output of 148.92MW to 160. 70MW, and 60.16% of the fuel energy input was lost to the power plant surroundings as waste heat. Also, the results obtained revealed that for a 1 0 C rise in ambient air temperature, there are drops of 1.16% in net power output and 1.58% net thermal efficiency, a 1.58% increase in SFC and HR, and a 0.64% decrease in WR. Furthermore, the results obtained showed that there was a lower performance of the plant at high ambient air temperature and a lower compressor pressure ratio and the exhaust gas waste heat can be utilized for a combined heat and power system. Accordingly, the study has provided an understanding of suitable information about the power plant that can be used for efficient operation and waste minimization as ways of performance enhancement of the SGT5-2000E Gas Turbine Power Plant in Benin City.

Sustainable opportunities to recover power plants’ waste heat: a benchmark of techno-economically optimized heat pumps

Current climate targets, adopted worldwide, pursue the decarbonization of all energy sectors. In power generation, the spread of RES has caused the shift of the Combined Cycle Gas Turbine (CCGT) power plants’ traditional role from providing constant baseload power to flexible operations providing services and backup capacity to the grid, as a consequence, the revenues opportunities on the traditional electricity markets (e.g., day-ahead, and intra-day markets) are no longer certain. At the same time is urgent to address a significant carbon intensity reduction in the heating sector, which is responsible for a large part of the current greenhouse gas emissions. Exploiting the low-exergy waste heat of CCGT’s water-cooled condenser as a thermal source for vapor compression heat pumps can meet two targets. On one hand, the revenues from heat production enhance the viability of the CCGT power plant, often essential for the security of the electrical supply. On the other hand, the heat delivered to the user represents a low-carbon alternative to traditional gas-fired boilers or even to air-sourced heat pumps characterized by lower efficiency. This work assesses the recovery of thermal energy from the sea cooling water at the bottoming cycle condenser of Tirreno Power 794 MWel CCGT in Vado Ligure through a high-temperature heat pump using R600 as a working fluid. Cooling water represents a privileged heat source and the integration into the power plant’s site allows running the HP at a lower cost than the electricity retail price. The case study takes into account the new Vado Ligure sports hall, to size the HP and explore the economic and environmental performances. The proposed layout is compared with the main solutions available: air source heat pump, gas, and electric boilers. The results show that on a lifespan of 20 years such integration of a heat pump with a CCGT could lead to consistent economical savings and emissions cuts.

Near-Optimal Decentralized Diagnosis via Structural Analysis

Health monitoring of current complex systems significantly impacts the total cost of the system. Centralized fault diagnosis architectures are sometimes prohibitive for large-scale interconnected systems, such as distribution systems, telecommunication networks, water distribution networks, or fluid power systems. Confidentiality constraints are also an issue. This article presents a decentralized fault diagnosis method that only requires the knowledge of local models and limited knowledge of their neighboring subsystems. The method, implemented in the decentralized diagnoser design ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$D^{3}$ </tex-math></inline-formula> ) algorithm, is based on structural analysis and can advantageously be applied to high-dimensional systems, linear or nonlinear. Using the concept of isolation on request, a hierarchy is built according to diagnostic objectives. The resulting diagnoser is based on analytical redundancy relations (ARRs) generated along the hierarchy. Their number is optimized via binary integer linear programming (BILP) while still guaranteeing maximal diagnosability at each level. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$D^{3}$ </tex-math></inline-formula> proves of lower time complexity than its centralized equivalent. It is successfully applied to a nonlinear combined cycle gas-turbine power plant.

Graphical Prediction of Optimum Pinch Point Value with AEA Software Simulation and Validation Applied in Closed Cycle Gas Power Plant

Studying industries energy saving is very important prospect for many researchers in the last four decades. In this respect, better process heat transfer can be achieved to improve process operating and capital cost. Thereafter, obtaining higher amount of heat recovery, which will help to reach system optimum heat exchanger network design. Application of Pinch analysis (PA) in our current study, was found to be as an effective method towards economic solution and assessment for all system thermal processes. Whereby, minimizing energy losses, and thus, prediction of maximum energy saving. In addition, application of "Aspen Energy Analyzer (AEA)" simulation software assist our effort to optimize Heat Exchanger Network design (HEN), with various application scenario towards best design. This study represents a "Case study" as a Brayton closed cycle gas turbine power plant in Al-khairat district, which is one of a number of sites used to generate electricity for Iraq national grid. However, the plant original design is open cycle. This study, represent an attempt to apply (PA) in system closed cycle model with the same working conditions. The results predicted, on the contrary of open cycle, that using closed cycle (PA) with temperature difference ∆Tmin can be acceptable with several design propositions. The optimum (∆Tmin = 15℃) were evaluated in the closed cycle system pinch analysis, thereby the maximum Qrec. process that minimize the QHmin &amp; QCmin requirement were identified by the software simulation for the best HEN design. These results were found as Qrec. = 318.330 MW, QHmin = 88.607 MW and QCmin =39.564 MW.

Comparative Thermodynamic Environmental and Economic Analyses of Combined Cycles Using Air and Supercritical CO2 in the Bottoming Cycles for Power Generation by Gas Turbine Waste Heat Recovery

This study aims to improve existing fossil gas turbine power plants by waste heat recovery. These power plants function with an air simple cycle (ASC) and are implemented where water resources are limited. Modeling and simulation of ASC and two advanced energy conversion systems are performed. They are the gas turbine–air bottoming cycle (GT-ABC) and gas turbine–supercritical carbon dioxide bottoming cycle (GT-sc-CO2BC). The main intent is to assess the benefits of employing sc-CO2 as a working fluid in a closed Brayton bottoming cycle compared to air, based on the energetic and exergetic performance and economic and environmental impact. Analyses of ASC, GT-ABC, and GT-sc-CO2BC are performed for various topping gas turbine powers: large (plant 1); medium (plant 2); and low (plant 3). The results of the energetic and exergetic analyses indicate that there is a significant improvement in the output power (ranging from 22% to 25%); and energy and exergy efficiencies of GT-ABC and GT-sc-CO2BC (up to 8% and 11%, respectively) compared to that of ASC. To provide better insight into the behavior of these technologies and achieve their better integration, we investigate the influence of varying the bottoming compressor pressure ratio, the ambient temperature, and the gas flow rate in the bottoming cycle. The results of the environmental and economic analyses show that the amount of CO2 emissions in GT-sc-CO2BC is reduced by 10% more than in GT ABC. The results also show that GT-ABC improves the NPV between 17.69% and 30% but GT-sc-CO2BC improves it even more, between 25.79% and 33.30%.

An experimental study of syngas combustion in a bidirectional swirling flow

The paper reports on the results of an experimental study of methane and syngas combustion as well as their co-firing in a bidirectional swirling flow. The results confirmed that the bidirectional flow structure provides a significant decrease in the lean blow-off equivalence ratio as well as that of emissions of main pollutants. The combustion intensification becomes more evident when using syngas is as fuel. The composition of the used syngas is as follows (by volume): H2 - 29.42%; CO - 14.32%; CH4 - 3.8%; N2 - 49.11%; H2O - 3.35%. In this case, the lean blow-off is achieved at ϕ < 0.1, NOx emission is halved, while CxHy and CO emissions become 20 times less compared to pure methane combustion. However, according to experimental results, the co-combustion of syngas (volume fraction Vsyn = 15%) and methane is the most appropriate fuel utilization mode. It provides blow-off and emission properties similar to those for combustion of pure syngas, whereas energy consumption for its production is much lower. Moreover, unlike hydrocarbon fuel combustion, that of syngas in a bidirectional swirling flow is characterized by the presence of density stratification. This is accompanied by the flame formation at significantly different locations in the combustion chamber at lean and “ultra-lean” modes of operation. Hydrogen combustion most likely to occur in the core region at near-blow-off modes ϕ < 0.1, whereas normal ‘operating modes in the range 0.2 = ϕ ≤ 0.4 result in the formation of a conical flame surface where CH4 and CO combustion occurs. These new results with respect to the flame structure as well as blow-off and emission properties make it possible to consider bidirectional vortex combustors for application in modern gas turbine power plants in order to meet the strict environmental and energy requirements.

Cost comparison of thermal storage power plants and conventional power plants for flexible residual load coverage

The paper presents a cost comparison of thermal storage power plants (TSPP) with various conventional power plants. TSPP require less fuel and can better fulfill the demand of variable and intermittent residual loads through providing a much higher flexibility with their intrinsic heat storage system, also called Carnot Battery. Due to reduced or completely avoided usage of fossil fuels, TSPP satisfy the goal of reducing greenhouse emissions in the current world. When comparing the LCOE of conventional power plants, such as biomass, coal, gas turbine and combined cycle power plants mentioned in this paper, with TSPP, the electricity cost of TSPP is lower than that of conventional power plants, no matter if they are newly built or obtained from converting existing plants. TSPP represent an effective hedge against the escalation of fossil fuel market prices as well as against rising CO2 cost additions. The comparison indicates that TSPP under current conditions are the most cost-effective way to produce highly flexible power on demand.

An equilibrium model of NOx emission in gas turbine combustors

In this study, an equilibrium model for NOx emission in gas turbine combustors was developed. The model is based on the governing thermodynamic, materials, and energy balance equations. Results obtained from the model simulation were compared with operational data from a local gas turbine power plant. There was about a 3 to 6 percent deviation for the periods considered. Consequently, the model is reliable in the design of new combustors and in assessing the pollutant emission during operations. It was established that factors that affect NOx formation include flame temperature and quantity of excess air used. Furthermore, the results revealed that the most important parameter that governs the formation of NOx is flame temperature, as the formation of NOx rises exponentially with an increase in the combustor flame temperature.

Numerical simulation on the hydrodynamic performance of high-pressure evaporator in once-through heat recovery steam generators

• The overall performance of once-through evaporator at all loads was simulated. • Flow network, models of metal temperature and flow instability were established. • Solving the flow instability trend of evaporator based on time domain method. • The safety of evaporator operation is evaluated from various factors. The once-through heat recovery steam generator (HRSG) of gas-turbine combined-cycle power plants adopts a triple-pressure reheat evaporator arrangement. To study the overall performance of the evaporator during operation, it’s divided into three sections: EVA1, EVA2, and EVA3 along the working fluid flow. In this study, in accordance with the heating load distribution characteristics of the evaporator and in consideration of the system mass, momentum, and energy conservation equations, the nonlinear mass and pressure drop balance equations are directly solved. The flow distribution, pressure drop distribution, profiles of working fluid temperature and outlet steam temperature of evaporator at boiler maximum continuous rating (BMCR), 75 % BMCR, and 30 % BMCR loads are analyzed. The flow distribution of evaporator at each load shows a positive response characteristic. The flow distribution at all levels is relatively reasonable, and there will be no heavy difference in the temperature and steam quality of fluid, which will lead to pulsation. Simulation results demonstrate that the metal properties can meet the requirements of material strength at each working condition, and the evaporator will not experience flow instability, stagnation, and pulsation at low loads. The triple-pressure once-through reheat HRSG can operate safely and reliably and has the advantage of lifting and lowering the load rapidly.

Modern Thermodynamic Analysis by the Energic-Exergic Method of Gas Turbine Power Plants 55 MW in Taza-Iraq

Abstract Because of the increasing demand for energy in the recent period, it has become necessary to intensify the study in the field of evaluating the performance of the gas station under the first and second laws efficiency. The energy and exergy losses of gas stations are represented by the compressor, combustion chamber, and turbine. Therefore, this work aims to analyze the energy and exergy of a 55 MW Taza gas power station. The investigation demonstrated that the most significant misfortunes of the exergy happened in the combustion chamber, where was 66.5MW the most minimal misfortunes in the compressor 5MW while the misfortunes in the turbine 8.4MW. The thermal efficiency of the gas turbine power plant was 33.06%, while the exergy efficiency was 32.39%. The novelty of the current work concentrated on obtaining the Grassmann graph for each component.

Performance analysis of selective exhaust gas recirculation integrated with fogging cooling system for gas turbine power plants

Selective exhaust gas recirculation (S-EGR) is a proposed alternative for enhancing the CO2 capture units applied in power plants. Most previous studies focused on the correlation between S-EGR and CO2 capture unit efficiency. Nevertheless, the S-EGR system without pre-cooling considerably influences the gas turbine output power due to its relatively high temperature. Hence this study aims to investigate the influence of the integration of fogging cooling systems with S-EGR on gas turbine performance. This combination could reduce the adverse effects of the S-EGR system in power plants as well as increase the effectiveness of the fogging cooling system in hot, humid regions. A three-dimensional Euler–Lagrange CFD model is employed to simulate the mutual effect between S-EGR and fogging cooling systems under different operation conditions. The impact of output condition from combined fogging and S-EGR system (cooled CO2 enriched air) on the gas turbine performance is then investigated. Results illustrate that applying the fogging cooling approach after mixing the inlet air and S-EGR reduces the moisture content of the inlet air and augments the cooling capacity of the fogging system. When the CO2-enriched stream is pre-cooled to the same ambient temperature, the fogging system outlet temperature drops more, especially at high S-EGR ratios. Applying the S-EGR system could increase the inlet mixture density (CO2-enriched air) by about 12% at an S-EGR ratio of 35%, which is increased to 18% after incorporating the fogging cooling system. Regarding gas turbine performance, using CO2-enriched air without pre-cooling leads to a significant deterioration in performance, notably at high S-EGR ratios. On the other hand, the amalgamation of S-EGR with fogging cooling could boost gas turbine output power from 11.7 to 19.2%, with an efficiency gain of half a percentage point.

Predicting the Impact of Compressor Flexibility Improvements on Heavy-Duty Gas Turbines for Minimum and Base Load Conditions

The increasing importance of renewable energy capacity in the power generation scenario, together with the fluctuating consumer energy demand, forces conventional fossil fuel power generation systems to promptly respond to relevant and rapid load variations and to operate under off-design conditions during a major fraction of their lives. In order to improve existing power plants’ flexibility in facing energy surplus or deficit, retrofittable solutions for gas turbine compressors are proposed. In this paper, two different operation strategies, variable inlet guide vanes (IGVs) and blow-off extraction (BO), are considered for enabling partial load and minimum environmental load operation, and thus to identify implementation opportunities in existing thermal power plants. A typical 15-stage F-class gas turbine compressor is chosen as a test case and some energy demand scenarios are selected to validate the adopted solutions. The results of an extensive 3D, steady, CFD analysis are compared with the measurements coming from an experimental campaign carried out in the framework of the European Turbo-Reflex project. It will be shown how the combined strategies can reduce gas turbine mass flow rate and power plant output, without significantly penalizing efficiency, and how such off-design performance figures can be reliably predicted by employing state-of-the-art CFD models.