Techno-Economic Study on Implementation of Inventory Control Requirements for a Nuclear Powered Closed-Cycle Gas Turbine Power Plant

2020 ◽  
Author(s):  
Emmanuel Osigwe ◽  
Arnold Gad-Briggs ◽  
Mafel Obhuo ◽  
Pericles Pilidis
Keyword(s):  
Control System ◽  
Gas Turbine ◽  
Inventory Control ◽  
Control Level ◽  
Cost Comparison ◽  
Closed Cycle ◽  
Part Load ◽  
Discharge Temperature ◽  
Tank Pressure ◽  
The Impact

Abstract The use of an inventory control system offers a unique benefit of stable cycle thermal efficiency during part-load operation. This article focuses on the influence of initial inventory tank pressure on the control level using pressure differential as a driving force of the inventory control system. The study also considered the effects of using multiple tanks to increase the overall size of the inventory control tank and the use of insulation to reduce the impact of temperature variation between the compressor discharge temperature and the inventory tank temperature. The second part of this analysis is a cost comparison between the use of multiple tanks and the use of a transfer compressor to achieve high cycle efficiency at continuous part-load operation. The discussions in this paper accentuate the optimum benefit for utilizing an inventory control system for a single-shaft intercooled-recuperated closed-cycle gas turbine plant.

Bypass Control of Closed-Cycle Gas Turbines

1978 ◽  
Author(s):  
G. Krey
Keyword(s):  
Control System ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Closed Cycle ◽  
Part Load ◽  
Control Behavior ◽  
Bypass Valve ◽  
Load Behavior

The layout of the bypass control system of a closed-cycle gas turbine depends on the steady and nonsteady part-load behavior of the plant. In the paper, the results of investigations into the operating behavior of closed-cycle gas turbines are summarized. From these a method of laying out the bypass valve is deduced. Finally, an advanced bypass control system is described and the control behavior achievable therewith is explained.

Modelling the Effect of External Flue Gas Recirculation on NOx and CO Emissions in a Premixed Gas Turbine Combustor With Chemical Reactor Networks

2018 ◽  
Author(s):  
V. Prakash ◽  
J. Steimes ◽  
D. J. E. M. Roekaerts ◽  
S. A. Klein
Keyword(s):  
Gas Turbine ◽  
Flue Gas ◽  
Recirculation Zone ◽  
Chemical Reactor ◽  
Inlet Temperature ◽  
Part Load ◽  
Flue Gas Recirculation ◽  
Reactor Networks ◽  
Gas Recirculation ◽  
The Impact

The increasing amount of renewable energy and emission norms challenge gas turbine power plants to operate at part-load with high efficiency, while reducing NOx and CO emissions. A novel solution to this dilemma is external Flue Gas Recirculation (FGR), in which flue gases are recirculated to the gas turbine inlet, increasing compressor inlet temperature and enabling higher part load efficiencies. FGR also alters the oxidizer composition, potentially leading to reduced NOx levels. This paper presents a kinetic model using chemical reactor networks in a lean premixed combustor to study the impact of FGR on emissions. The flame zone is split in two perfectly stirred reactors modelling the flame front and the recirculation zone. The flame reactor is determined based on a chemical time scale approach, accounting for different reaction kinetics due to FGR oxidizers. The recirculation zone is determined through empirical correlations. It is followed by a plug flow reactor. This method requires less details of the flow field, has been validated with literature data and is generally applicable for modelling premixed flames. Results show that due to less O2 concentration, NOx formation is inhibited down to 10–40% and CO levels are escalated up to 50%, for identical flame temperatures. Increasing combustor pressure leads to a rise in NOx due to thermal effects beyond 1800 K, and a drop in CO levels, due to the reduced chemical dissociation of CO2. Wet FGR reduces NOx by 5–10% and increases CO by 10–20%.

Semi-Closed Gas Turbine Cycles: An Ecological Solution

2001 ◽  
Author(s):  
A. L. Laganelli ◽  
C. Rodgers ◽  
W. E. Lear ◽  
P. L. Meitner
Keyword(s):  
Global Warming ◽  
Greenhouse Gases ◽  
Gas Turbine ◽  
Fossil Fuels ◽  
High Efficiency ◽  
Anthropogenic Heat ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Closed Cycle ◽  
The Impact

The impact on global warming of transportation and the infrastructure that supports it has been investigated over several decades. Anthropogenic heat and the generation of greenhouse gases from burning of fossil fuels and are major contributors to the warming process. An approach to mitigate these effects is discussed that considers semi-closed cycle gas turbine engines as a practical approach to slowing the release of greenhouse gases. Semi-closed cycle gas turbine engines have an inherent capability to reduce all regulated emissions while maintaining high efficiency, which in turn reduces CO2 emissions. With emerging technology development that includes higher component efficiencies, high temperature material development, improved control devices, and advanced combustor designs, aided by computational fluid dynamics, semi-closed cycle engines appear to have the potential to mitigate global warming with little economic or infrastructural impact. A specific semi-closed engine type is described, the high pressure recuperated turbine engine (HPRTE), along with the inherent mechanisms for control of NOx, CO, unburned hydrocarbons, and particulates. Results from a breadboard demonstration of the HPRTE are discussed, as well as emerging technologies which benefit this type of engine.

CCPP Operational Flexibility Extension Below 30% Load Using Reheat Burner Switch-Off Concept

2015 ◽  
Author(s):  
Dirk Therkorn ◽  
Martin Gassner ◽  
Vincent Lonneux ◽  
Mengbin Zhang ◽  
Stefano Bernero
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Fast Response ◽  
Combined Cycle ◽  
Pollutant Emissions ◽  
Inlet Temperature ◽  
Operational Flexibility ◽  
Part Load ◽  
Combustion Technology ◽  
The Impact

Highly competitive and volatile energy markets are currently observed, as resulting from the increased use of intermittent renewable sources. Gas turbine combined cycle power plants (CCPP) owners therefore require reliable, flexible capacity with fast response time to the grid, while being compliant with environmental limitations. In response to these requirements, a new operation concept was developed to extend the operational flexibility by reducing the achievable Minimum Environmental Load (MEL), usually limited by increasing pollutant emissions. The developed concept exploits the unique feature of the GT24/26 sequential combustion architecture, where low part load operation is only limited by CO emissions produced by the reheat (SEV) burners. A significant reduction of CO below the legal limits in the Low Part Load (LPL) range is thereby achieved by individually switching the SEV burners with a new operation concept that allows to reduce load without needing to significantly reduce both local hot gas temperatures and CCPP efficiency. Comprehensive assessments of the impact on operation, emissions and lifetime were performed and accompanied by extensive testing with additional validation instrumentation. This has confirmed moderate temperature spreads in the downstream components, which is a benefit of sequential combustion technology due to the high inlet temperature into the SEV combustor. The following commercial implementation in the field has proven a reduction of MEL down to 26% plant load, corresponding to 18% gas turbine load. The extended operation range is emission compliant and provides frequency response capability at high plant efficiency. The experience accumulated over more than one year of successful commercial operation confirms the potential and reliability of the concept, which the customers are exploiting by regularly operating in the LPL range.

scholarly journals Helium and Combustion Gas Turbine Power Conversion Systems Comparison

1995 ◽  
Author(s):  
Colin F. McDonald
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Conversion ◽  
Practical Experience ◽  
Working Fluid ◽  
Major Theme ◽  
Closed Cycle ◽  
Combustion Gas ◽  
Conversion System ◽  
The Impact

For closed-cycle gas turbines, in a size to meet utility power generation needs, the selection of helium as the working fluid represents the best solution in terms of the overall power conversion system considering the differing requirements of the turbomachinery and heat exchangers. Helium is well suited for the nuclear Brayton cycle because it is neutronically inert. The impact of helium’s unique properties on the performance and size of the power conversion system components is discussed in this paper. The helium gas turbine plants, that have operated were based on 1950s and 1960s technology, represent a valuable technology base in terms of practical experience gained. However, the design of the Gas Turbine Modular Helium Reactor (GT-MHR), which could see utility service in the first decade of the 21st century will utilize turbomachinery and heat exchanger technologies from the combustion gas turbine and aerospace industries. An understanding of how the design of power conversion systems for closed-cycle plants and combustion gas turbines are affected by the working fluids (i.e., helium and air, respectively) is the major theme of this paper.

Analysing the impact of different classical controller strategies on the dynamics performance of production-inventory systems using state space approach

2018 ◽  
Vol 13 (1) ◽  
pp. 211-235 ◽  
Author(s):  
Huthaifa AL-Khazraji ◽  
Colin Cole ◽  
William Guo
Keyword(s):  
Control System ◽  
State Space ◽  
Inventory Control ◽  
Bullwhip Effect ◽  
Inventory Level ◽  
State Space Approach ◽  
Content Type ◽  
Production Inventory ◽  
The Impact ◽  
Space Approach

Purpose The purpose of this paper is to examine the impact of applying two classical controller strategies, including two proportional (P) controllers with two feedback loops and one proportional–integral–derivative (PID) controller with one feedback loop, on the order and inventory performance within a production-inventory control system. Design/methodology/approach The simulation experiments of the dynamics behaviour of the production-inventory control system are conducted using a model based on control theory techniques. The Laplace transformation of an Order–Up–To (OUT) model is obtained using a state-space approach, and then the state-space representation is used to design and simulate a controlled model. The simulations of each model with two control configurations are tested by subjecting the system to a random retail sales pattern. The performance of inventory level is quantified by using the Integral of Absolute Error (IAE), whereas the bullwhip effect is measured by using the Variance ratio (Var). Findings The simulation results show that one PID controller with one feedback loop outperforms two P controllers with two feedback loops at reducing the bullwhip effect and regulating the inventory level. Originality/value The production-inventory control system is broken down into three components, namely: the forecasting mechanism, controller strategy and production-inventory process. A state-space approach is adopted to design and simulate the different controller strategy.

scholarly journals The Impact of Feedback Information on Dynamics Performance of Production-Inventory Control Systems

2021 ◽  
Author(s):  
Huthaifa AL-Khazraji ◽  
Colin Cole ◽  
William Guo
Keyword(s):  
Control System ◽  
Control Systems ◽  
Inventory Control ◽  
Bullwhip Effect ◽  
Absolute Error ◽  
Feedback Information ◽  
Simulation Based ◽  
Production Inventory ◽  
Beneficial Impact ◽  
The Impact

The aim of this paper is to examine the beneficial impact of feedback information in the dynamics of production-inventory control systems. Two production-inventory control system models are analyzed: APIOBPCS and 2APIOBPCS models. The simulation-based experiment designs were conducted by using the state-space equations of the two models. The bullwhip effect as measured by the variance ratio between the order rate and the consumption rate, and inventory responsiveness as measured by the Integral of Absolute Error between the actual and the target levels of inventory, are two metrics used to evaluate the performance of the production-inventory control system in response to a random customer demand. To ensure that both models work under optimal performance, multi-objective particle swarm optimization (MOPSO) is employed to address the problem of tuning the controller’s parameters. The simulation results show the 2APIOBPCS model outperforms the APIOBPCS model at achieving the desired bullwhip effect and being able to provide better inventory responsiveness. The improvement in the inventory responsiveness becomes more significant when the system operates under mismatched lead time and/or an initial condition.

scholarly journals Rapid Positive Load Changes by Gas Injection in Closed Gas Turbine Cycles

1978 ◽  
Author(s):  
H. U. Frutschi
Keyword(s):  
Control System ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Gas Injection ◽  
Load Reduction ◽  
Control Methods ◽  
Power Demand ◽  
Closed Cycle ◽  
Autonomous Operation

Spontaneous response to power demand is essential during autonomous operation of power plants. In this case, only control principles with negligible negative momentary effects can be employed. A further requirement is a good part-load efficiency. After a brief description of the most important control methods of closed-cycle gas turbines, the dynamic behavior of the cycle during gas injection for positive load changes is analyzed. A very attractive method is inter-compressor injection from an intermediate pressure reservoir which can be charged from the compressor exit during load reduction. Based on these results, a control system for closed-cycle gas turbine employing gas injection is presented.

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