Thermal Performance Prediction of a Biomass Based Integrated Gasification Combined Cycle Plant

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
T. Srinivas ◽  
B. V. Reddy ◽  
A. V. S. S. K. S. Gupta

The performance characteristics of a rice husk based integrated gasification combined cycle (IGCC) plant has been developed at the variable operating conditions of gasifier. A thermo-chemical model developed by the authors has been applied for wet fuel (fuel with moisture) for predicting the gas composition, gas generation per kg of fuel, plant efficiency and power generation capacity, and NOx and CO2 emissions. The effect of the relative air fuel ratio (RAFR), steam fuel ratio (SFR), and gasifier pressure has been examined on the plant electrical efficiency, power output, and NOx and CO2 emissions of the plant with and without supplementary firing (SF) between gas turbine (GT) outlet and heat recovery steam generator (HRSG). The optimum working conditions for efficient running of the IGCC plant are 0.25 RAFR, 0.5 SFR, and 11 bar gasifier pressure at the GT inlet temperature of 1200 °C. The optimum operational conditions of the gasifier for maximum efficiency condition are different compared to maximum power condition. The current IGCC plant results 264.5 MW of electric power with the compressor air flow rate of 375 kg/s at the existed conventional combined cycle plant conditions (Srinivas et al., 2011, “Parametric Simulation of Combined Cycle Power Plant: A Case Study,” Int. J. Thermodyn. 14(1), pp. 29–36). The optimum compressor pressure ratio increases with increase in GT inlet temperature and decreases with addition of SF.

2021 ◽  
Author(s):  
Silvia Ravelli

Abstract This study takes inspiration from a previous work focused on the simulations of the Willem-Alexander Centrale (WAC) power plant located in Buggenum (the Netherlands), based on integrated gasification combined cycle (IGCC) technology, under both design and off-design conditions. These latter included co-gasification of coal and biomass, in proportions of 30:70, in three different fuel mixtures. Any drop in the energy content of the coal/biomass blend, with respect to 100% coal, translated into a reduction in gas turbine (GT) firing temperature and load, according to the guidelines of WAC testing. Since the model was found to be accurate in comparison with operational data, here attention is drawn to the GT behavior. Hence part load strategies, such as fuel-only turbine inlet temperature (TIT) control and inlet guide vane (IGV) control, were investigated with the aim of maximizing the net electric efficiency (ηel) of the whole plant. This was done for different GT models from leading manufactures on a comparable size, in the range between 190–200 MW. The influence of fuel quality on overall ηel was discussed for three binary blends, over a wide range of lower heating value (LHV), while ensuring a concentration of H2 in the syngas below the limit of 30 vol%. IGV control was found to deliver the highest IGCC ηel combined with the lowest CO2 emission intensity, when compared not only to TIT control but also to turbine exhaust temperature control, which matches the spec for the selected GT engine. Thermoflex® was used to compute mass and energy balances in a steady environment thus neglecting dynamic aspects.


Author(s):  
M. W. Horner ◽  
G. A. Cincotta ◽  
A. Caruvana

This paper presents the results of three significant tests recently performed by GE under the DOE High Temperature Turbine Technology Phase II Program contract. The first test involved a simulated Integrated Gasification Combined Cycle (IGCC) test of a water-cooled composite nozzle exposed to low Btu coal gas at design operating conditions (2600 F + firing temperature, 12 atm pressure). The second test is that of a water-cooled monolithic nozzle, a full-scale model of the second-stage nozzle planned for the Technology Readiness Vehicle Verification Test. The third test demonstrates coolant water delivery, transfer, and metering distribution, from the stationary feed line to the turbine rotor, enroute to individual bucket airfoil coolant passages. These tests successfully demonstrated the IGCC operation with very good results, and show every indication that operation at firing temperatures up to 3000 F is well within the design capability of the water-cooled turbine.


Author(s):  
Vahid Noei Aghaei ◽  
Bahador Bakhtiari ◽  
Hiwa Khaledi ◽  
Mohammad Bagher Ghofrani

Current researches on the development of gas turbine related power plants such as HAT cycle and Combined Cycle are aimed to increase the plant efficiency and output power, while reducing the cost of power generation and emission. Humid air turbine cycle (HAT) is one of innovative cycles, which are able to provide a substantial power boost of the system and an efficiency rise of several percentage points. In order to perform energy analysis of Full Flow HAT cycle and Part Flow HAT cycle an advanced thermodynamic model is developed, which is enabling evaluation of behavior of Full Flow and Part Flow Humid Air Turbines and predicting the influence of operational parameters in the performance of these cycles. Changes in level of cooling technology are introduced in the model. Results show that this parameter has great influence on the cycle efficiency, especially at high Turbine Inlet Temperature (TIT). Also to model the accurate behavior of humid air, a new thermodynamic model is used to predict thermodynamic properties of air-water mixture at elevated temperature and pressure. In The pressure, in which compressor divided into two sections (LP/HP) is considered to find the optimum performance of cycle. Finally performance of Part Flow HAT cycle at different operating conditions (compressor pressure ratio, TIT) and bypass factors is verified and compared with Full Flow HAT cycle. Results show that in Part Flow HAT cycle changes in bypass factor has little influence on performance of the cycle. Furthermore, Part Flow HAT cycle exhibits better performance (compared to Full Flow HAT cycle) at high pressure ratio region, and vice versa at low pressure ratio region.


Author(s):  
S Ghosh ◽  
S De

In this paper an integrated gasification combined cycle (IGCC) with a high-temperature, pressurized solid oxide fuel cell (SOFC) in the topping cycle and a single-pressure, non-reheat steam bottoming cycle has been conceptualized and analysed. An energy analysis is done for this combined cycle. The study reveals that an overall efficiency above 54 per cent is achievable for this combined cycle, which also offers satisfactory environmental friendliness. A higher pressure ratio across the gas turbine is found to improve the overall efficiency of the combined cycle. The SOFC operating temperature is found to influence the performance of the combined cycle in different ways, depending on the pressure ratios.


Author(s):  
Michael Tsurikov ◽  
Wolfgang Meier ◽  
Klaus-Peter Geigle

In order to investigate the combustion behavior of gas turbine flames fired with low-caloric syngases, a model combustor with good optical access for confined, non-premixed swirl flames was developed. The measuring techniques applied were particle image velocimetry, OH* chemiluminescence detection and laser-induced fluorescence of OH. Two different fuel compositions of H2, CO, N2 and CH4, with similar laminar burning velocities, were chosen. Their combustion behavior was studied at two different pressures, two thermal loads and two combustion air temperatures. The overall lean flames (equivalence ratio 0.5) burned very stably and their shapes and combustion behavior were hardly influenced by the fuel composition or by the different operating conditions. The experimental results constitute a data-base that will be used for the validation of numerical combustion models and form a part of a co-operative EC project aiming at the development of highly efficient gas turbines for IGCC (Integrated Gasification Combined Cycle) power plants.


Author(s):  
Feliciano Pava´n ◽  
Marco Romo ◽  
Juan Prince

The present paper is a thermodynamics analysis, i.e. both energy and exergy analyses for a natural gas based combined cycle power plant. The analysis was performed for an existing 240 MW plant, where the steam cycle reduces the irreversibilities during heat transfer from gas to water/steam. The effect of operating variables such as pressure ratio, gas turbine inlet temperature on the performance of combined cycle power plant has been investigated. The pressure ratio and maximum temperature (gas turbine inlet temperature) are identified as the dominant parameters having impact on the combined cycle plant performance. The work output of the topping cycle is found to increase with pressure ratio, while for the bottoming cycle it decreases. However, for the same gas turbine inlet temperature the overall work output of the combined cycle plant increases up to a certain pressure ratio, and thereafter not much increase is observed. The exergy losses of the individual components in the plant are evaluated based on second law of thermodynamics. The present results form a basis on which further work can be conducted to improve the performance of these units.


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