An Innovative Inlet Air Cooling System for IGCC Power Augmentation: Part II—Thermodynamic Analysis

2012 ◽  
Author(s):  
Mirko Morini ◽  
Michele Pinelli ◽  
Pier Ruggero Spina
Keyword(s):  
Gas Turbine ◽  
Air Temperature ◽  
Power Plants ◽  
Cooling System ◽  
Ambient Air ◽  
Combined Cycle ◽  
Air Separation ◽  
Air Cooling ◽  
Separation Unit ◽  
Gasification Process

Integrated Gasification Combined Cycles (IGCCs) are energy systems mainly composed of a gasifier and a combined cycle power plant. Since the gasification process usually requires oxygen as the oxidant, the plant also has an Air Separation Unit (ASU). Moreover, a producer gas cleaner unit is always present between the gasifier and the gas turbine. Since these plants are based on gas-steam combined cycle power plants they suffer from a reduction in performance when ambient temperature increases. In this paper, an innovative system for power augmentation in IGCC plants is presented. The system is based on gas turbine inlet air cooling by means of liquid nitrogen spray. In fact, nitrogen is a product of the ASU, but is not always exploited. In the proposed plant, the nitrogen is first chilled and liquefied and then it can be used for inlet air cooling or stored for a postponed use. This system is not characterized by the limits of water evaporative cooling (where the lower temperature is limited by air saturation) and refrigeration cooling (where the effectiveness is limited by pressure drop in the heat exchanger). A thermodynamic model of the system is built by using a commercial code for the simulation of energy conversion systems. A sensitivity analysis on the main parameters (e.g. ambient air temperature, inlet air temperature difference, etc.) is presented. Finally the model is used to study the capabilities of the system by imposing the real temperature profiles of different sites for a whole year.

Gas Turbine Performance Enhancement by Inlet Air Cooling and Coolant Pre-Cooling Using an Absorption Chiller

2016 ◽  
Author(s):  
Hyun Min Kwon ◽  
Jeong Ho Kim ◽  
Tong Seop Kim
Keyword(s):  
Gas Turbine ◽  
Air Temperature ◽  
Power Plants ◽  
Cooling System ◽  
Combined Cycle ◽  
Air Cooling ◽  
Absorption Chiller ◽  
Large Power ◽  
Cycle Simulation ◽  
Standard Design

The gas turbine combined cycle is the most mature and efficient power generation system. While enhancing design performance continuously, a parallel effort to make up for the shortcomings of the gas turbine should be pursued. The most critical drawback is the large power loss in hot season when electricity demand is usually the highest. Therefore, it is important to implement an effective power boosting measure in gas turbine based power plants, especially in areas where the annual average temperature is much higher than the standard design ambient temperature. The simplest method in general is to reduce the gas turbine inlet air temperature by any means. Several schemes are commercially available, such as mechanical chilling, evaporative cooling, inlet fogging and absorption chilling. All of them have merits and demerits, either thermodynamically and economically. In this study, we focused our interest on the absorption chilling method. Theoretically, absorption chilling provides as much cooling effect (air temperature reduction) as the mechanical chilling, while electric power consumption is negligibly small. A distinct feature of an absorption chiller in contrast to a mechanical chiller is that thermal energy (heat) is needed to drive the chilling system. In this research, we propose an innovative idea of making the independent heat supply unnecessary. The new method provides simultaneous cooling of the turbine coolant and the inlet air using an absorption chiller. The inlet cooling and coolant precooling boost the gas turbine power synergistically. We predicted the system performance using cycle simulation and compared it with that of the conventional mechanical cooling system.

An Innovative Inlet Air Cooling System for IGCC Power Augmentation: Part I—Analysis of IGCC Plant Components

2012 ◽  
Author(s):  
Mirko Morini ◽  
Mauro Venturini
Keyword(s):  
Simulation Model ◽  
Power Plants ◽  
Cooling System ◽  
Combined Cycle ◽  
Air Separation ◽  
Air Cooling ◽  
Ambient Conditions ◽  
Characteristic Energy ◽  
Separation Unit ◽  
Plant Components

Integrated Gasification Combined Cycle (IGCC) power plants are energy systems mainly composed of a gasifier and a combined cycle power plant. Since the gasification process usually requires oxygen as the oxidant, an Air Separation Unit is also part of the plant. Moreover, a producer gas cleaning unit is always present between the gasifier and the gas turbine. With respect to Natural Gas Combined Cycles (NGCCs), IGCCs are characterized by a consistent loss in the overall plant efficiency due to the conversion of the raw fuel in the gasifier and the electrical power parasitized for fuel production which considerably reduces plant net electric power. In order to reduce this loss, synergies among the different components of the plant should be improved. In this paper, an analysis of state-of-the-art IGCC plant components is presented. Particular interest is given to characteristic energy and flow streams in order to evaluate possible synergies and optimizations. Moreover, a simulation model of an IGCC plant, built in a commercial energy system simulation environment, is set up and the influence of ambient conditions on IGCC net power output is analyzed. The suggestions gained from the current paper and the simulation model will be used in the Part II of this paper to evaluate the capability of a strategy for IGCC power augmentation, based on ASU discharged nitrogen utilization.

Analysis of Gas Turbine Performance in IGCC Plants Considering Compressor Operating Condition and Turbine Metal Temperature

2009 ◽  
Author(s):  
Y. S. Kim ◽  
J. J. Lee ◽  
K. S. Cha ◽  
T. S. Kim ◽  
J. L. Sohn ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Combined Cycle ◽  
Air Separation ◽  
Metal Temperature ◽  
Integrated Gasification Combined Cycle ◽  
Separation Unit ◽  
Gasification Process ◽  
Surge Margin ◽  
Compressor Surge ◽  
Integration Degree

An IGCC (integrated gasification combined cycle) plant couples a power block to a gasification block. The method of integrating a gas turbine with a gasification process is the major design option. Matching between the gas turbine and the air separation unit is especially important. This study analyzes the influences of IGCC design options on the operability and performance of the gas turbine. Another research focus is given to the estimation of the change of turbine metal temperature in the IGCC operating environment. For this purpose, a full off-design analysis of the gas turbine is used with the turbine blade cooling model. Four different syngas fuels are considered. As the integration degree becomes lower, the gas turbine power and efficiency increase. However, a lower integration degree causes a reduction of the compressor surge margin and overheating of the turbine metal. Only near 100% integration degree designs are almost free of those two problems. The syngas property also affects the gas turbine operation. As the heating value gets lower, the problems of surge margin reduction and metal overheating become more severe. Modifications of the compressor (adding a couple of stages) and the turbine (increasing gas path area) could solve the compressor surge problem. However, the turbine overheating problem still exists. In particular, the turbine modification is predicted to overheat turbine metal considerably.

Technical and Economical Evaluation of Media and Fog Systems in Fars, Qom, Yazd, Shahid Rajaee Power Plants

2012 ◽  
Vol 433-440 ◽  
pp. 7229-7233
Author(s):  
Karim Maghsoudi Mehraban ◽  
Seyyed Vahid Mahmoodi Jezeh ◽  
Seyyed Hossein Musa Kazemi
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Air Temperature ◽  
Power Plants ◽  
Cooling System ◽  
Combined Cycle ◽  
Power House ◽  
Economical Evaluation ◽  
Hot Days ◽  
Media Systems

In the hot days of summer, the efficiency of gas turbine is extremely reduced because the input air to compressors becomes hot. For solving this problem, one can increase the efficiency of the power house by charging to decrease the input air temperature to the compressor of gas turbine. In this paper, all kinds of cooling the inlet air to the gas turbine are introduced and then the technical and economical evaluation of these installed cooling system in Shahid Rajaee, Qom, Fars and Yazd power plants are expressed and the results show that the fog system cannot prove its effectiveness in Shahid Rajaee and Qom power plants. Whereas the installation of media systems in Fars combined cycle power plant produces more megawatt than its guarantee conditions and no particular problem has been observed.

Comparison Between Oxygen-Blown and Air-Blown IGCC Power Plants: A Gas Turbine Perspective

2011 ◽  
Author(s):  
Prashant S. Parulekar
Keyword(s):  
Power Plants ◽  
Ambient Air ◽  
End Users ◽  
Combined Cycle ◽  
Air Separation ◽  
Integrated Gasification Combined Cycle ◽  
Gaseous Oxygen ◽  
Separation Unit ◽  
Advantages And Disadvantages ◽  
Integrated Gasification

The gasifier in an Integrated Gasification Combined Cycle (IGCC) Power Plant gasifies coal using an oxidant gas that facilitates partial combustion and effective gasification of the coal feed. When electricity generation is the prime objective of the IGCC facility this oxidant can be ambient air, or gaseous oxygen produced from an Air Separation Unit (ASU). Gasification technology providers are presently divided in their type of offering and information in the public domain does not effectively guide End Users in the advantages and disadvantages of the two gasification methods as applicable to the particular project being developed. This paper highlights key design aspects that should guide End Users in making an effective assessment and perform detailed evaluation of the gasification technologies for the particular IGCC project in consideration.

GT Inlet Air Boosting and Cooling Coupled With Cold Thermal Storage in Combined Cycle Power Plants

2008 ◽  
Author(s):  
Nicola Palestra ◽  
Giovanna Barigozzi ◽  
Antonio Perdichizzi
Keyword(s):  
Gas Turbine ◽  
Energy Production ◽  
Power Plants ◽  
Cooling System ◽  
Electric Energy ◽  
Thermal Storage ◽  
Combined Cycle ◽  
Inlet Pressure ◽  
Air Cooling ◽  
Air Cooling System

Investigation results of compressor inlet air boosting and cooling, applied to combined cycle power plants, are presented and discussed. Gas turbine performances may be reduced by site altitude and inlet losses due to air ducts and filters. Increasing inlet pressure by fans allows the restoring of gas turbine power output and efficiency at least to ISO reference conditions. Coupling such a system with inlet air cooling may completely suppress the temperature increase given by inlet air compression and the pressure losses through air coils as well; therefore, by this way, a further increase of electric energy production can be achieved. An in-house simulation code, developed for evaluating inlet air cooling system performance by cool thermal storage, has been adapted in order to also simulate off-design behaviour of boosting applied to combined cycle plants. A 127 MW reference power plant, operating in the Italian scenario, has been considered. Inlet pressure increase has been evaluated with and without inlet cooling, and in comparison with inlet cooling solution alone. Both thermodynamic and economical results have been analyzed. A parametric analysis on both system sizing parameters has been carried out. Best solution was found in coupling boosting to inlet cooling system through cool thermal storage; it produced an important increase in electric energy production. Location site influence on investment pay-back proved to be less important compared to the solution with inlet air cooling system alone.

Effect of Inlet Air Cooling by Absorption Chiller on Gas Turbine and Combined Cycle Performance

2005 ◽  
Author(s):  
Hiwa Khaledi ◽  
Roozbeh Zomorodian ◽  
Mohammad Bagher Ghofrani
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Cooling System ◽  
Positive Influence ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Air Cooling ◽  
Internal Source ◽  
Absorption Chiller

Gas turbine performances are directly related to site conditions. The use of gas turbines in combined gas-steam power plants, also applied to cogeneration, increases such dependence. In recent years, inlet air cooling systems have been introduced to control air temperature at compressor inlet, resulting in an increase in plant power and efficiency. In this paper, the dependence of outside conditions for a simple gas turbine and a combined cycle plant is studied, using absorption chiller as inlet air cooling system. We used, as case study, a simple plant equipped with one frame E gas turbine and a combined cycle with a two pressure level heat recovery steam generator (HRSG). It was found that inlet air cooling with absorption chiller has great positive influence on power and less on efficiency of the gas turbine plant. Two steam sources (External and Internal) have been considered for chiller. External source has large positive influence on power but keep the efficiency of the combined cycle unchanged, while internal source causes a reduction in steam turbine mass flow. Consequently power production and efficiency of the combined cycle decrease. This reduction is lower in mid temperature (25 to 35°C) but higher in high temperature (35 to 45°C). Inlet cooling would result in lowering turbine exhaust temperature, thus decreasing the efficiency of HRSG.

Optimization of fog inlet air cooling system for combined cycle power plants using genetic algorithm

2015 ◽  
Vol 76 ◽  
pp. 449-461 ◽  
Author(s):  
Mehdi A. Ehyaei ◽  
Mojtaba Tahani ◽  
Pouria Ahmadi ◽  
Mohammad Esfandiari
Keyword(s):  
Genetic Algorithm ◽  
Power Plants ◽  
Cooling System ◽  
Combined Cycle ◽  
Air Cooling ◽  
Air Cooling System

Inlet Air Cooling Applied to Combined Cycle Power Plants: Influence of Site Climate and Thermal Storage Systems

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Nicola Palestra ◽  
Giovanna Barigozzi ◽  
Antonio Perdichizzi
Keyword(s):  
Power Output ◽  
Parametric Analysis ◽  
Power Plants ◽  
Cooling System ◽  
Thermal Storage ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Air Cooling ◽  
Ambient Conditions ◽  
Cooling Systems

The paper presents the results of an investigation on inlet air cooling systems based on cool thermal storage, applied to combined cycle power plants. Such systems provide a significant increase of electric energy production in the peak hours; the charge of the cool thermal storage is performed instead during the night time. The inlet air cooling system also allows the plant to reduce power output dependence on ambient conditions. A 127MW combined cycle power plant operating in the Italian scenario is the object of this investigation. Two different technologies for cool thermal storage have been considered: ice harvester and stratified chilled water. To evaluate the performance of the combined cycle under different operating conditions, inlet cooling systems have been simulated with an in-house developed computational code. An economical analysis has been then performed. Different plant location sites have been considered, with the purpose to weigh up the influence of climatic conditions. Finally, a parametric analysis has been carried out in order to investigate how a variation of the thermal storage size affects the combined cycle performances and the investment profitability. It was found that both cool thermal storage technologies considered perform similarly in terms of gross extra production of energy. Despite this, the ice harvester shows higher parasitic load due to chillers consumptions. Warmer climates of the plant site resulted in a greater increase in the amount of operational hours than power output augmentation; investment profitability is different as well. Results of parametric analysis showed how important the size of inlet cooling storage may be for economical results.

scholarly journals Investigation of Applicability of Polyimide Membranes for Air Separation in Oxy-MILD Zero-Emission Power Plants

2019 ◽  
Vol 137 ◽  
pp. 01033
Author(s):  
Leszek Remiorz ◽  
Grzegorz Wiciak ◽  
Krzysztof Grzywnowicz
Keyword(s):  
Power Plants ◽  
Ambient Air ◽  
Continuous Functions ◽  
Air Separation ◽  
Low Oxygen ◽  
Recovery Coefficient ◽  
Separation Unit ◽  
Operational Conditions ◽  
Serial Connection ◽  
Zero Emission

Primary element of an oxy-combustion plants is ambient air separation unit. This paper presents the results of experimental research concerning the parameters of the separation of N2/O2 from ambient air, using capillary polymer membranes, potentially applicable in oxy-combustion technology, under variable operational conditions. Collected data were utilized to approximate continuous functions describing the variability of essential parameters of the air separation based on such membranes. The functions were introduced to develop a complete mathematical model of the separation unit, intended to be applied in oxy-Moderate or Intense Low Oxygen Dilution (oxy-MILD) zero-emission plants. Computational analyses were performed for three variants of the unit’s configuration: serial connection of membrane modules, unit with retentate recirculation and unit with permeate recirculation. The results of the research, in the form of sets of characteristic curves, depicting parameters of the separation process as a function of the variable operational conditions, show that crucial differences to the subsequent separation parameters (permeate purity, real selectivity coefficient, recovery coefficient) and with regard to the power consumed, were obtained. The highest parameters of the module were gained for serial connection, whereas the lowest – for permeate recirculation. The lowest energy consumption was acquired for the retentate recirculation variant.

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