scholarly journals Energy performance analysis of GE-F5 gas turbines at off-design conditions by applying an innovative convergent–divergent system for the inlet air cooling

2019 ◽  
Vol 52 (9-10) ◽  
pp. 1508-1516
Author(s):  
Seyed Mehdi Arabi ◽  
Hossein Ghadamian ◽  
Mohammad Aminy ◽  
Hassan Ali Ozgoli ◽  
Behzad Ahmadi ◽  
...  
Keyword(s):  
Output Power ◽  
Air Temperature ◽  
Gas Turbines ◽  
Power Plants ◽  
Characteristic Curve ◽  
Ambient Air ◽  
Energy Performance ◽  
Air Cooling ◽  
Design Algorithm ◽  
Ambient Air Temperature

Ambient air temperature increase, in a gas power plant, causes the intake air mass flow rate to be decreased and can have a significant reducing effect on output power and efficiency. To compensate for this reduction, at different climate conditions, various systems can be used to cool the inlet air. To predict the performance of a gas turbine at off-design conditions (by changing surrounding conditions and/or the air cooling method), modeling of the unit performance is required. Due to the high consumption of water and electricity in the conventional cooling systems, in this paper, in addition to introducing an off-design algorithm, governing equations of each cycle elements were inferenced by their characteristic curve. By developing code in MATLAB software, the effect of applying a novel convergent–divergent system on GE-F5 gas units in Yazd Zanbagh power plants was studied. The results show that in a temperature range between 14 and 50 °C, for each degree decrease in ambient air temperature, an approximately 8.99 kW increase in output power can be obtained. The main advantage of this system is the capability of its application in both dry and humid regions. In addition, the refrigerant medium is not required, which makes this system desirable to use in arid areas.

Thermodynamic Evaluation of a 42MW Gas Turbine Power Plant

2014 ◽  
Vol 12 ◽  
pp. 83-94 ◽  
Author(s):  
Henry Egware ◽  
Albert I. Obanor ◽  
Harrison Itoje
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Air Temperature ◽  
Power Plants ◽  
Exergy Analysis ◽  
Ambient Air ◽  
Thermodynamic Evaluation ◽  
Ambient Air Temperature ◽  
Energy And Exergy ◽  
Gas Turbine Power Plant

Energy and exergy analyses were carried out on an active 42MW open cycle gas turbine power plant. Data from the power plant record book were employed in the investigation. The First and Second Laws of Thermodynamics were applied to each component of the gas power plant at ambient air temperature range of 21 - 330C. Results obtained from the analyses show that the energy and exergy efficiencies decrease with increase in ambient air temperature entering the compressor. It was also shown that 66.98% of fuel input and 54.53% of chemical exergy are both lost to the environment as heat from the combustion chamber in the energy and exergy analysis respectively. The energy analysis quantified the efficiency of the plant arising from energy losses , while exergy analysis revealed the magnitude of losses in various components of the plant. Therefore a complete thermodynamic evaluation of gas turbine power plants requires the use of both analytical methods.

Inlet Air Supercharging of a 70 kW Microturbine

2006 ◽  
Author(s):  
Robert Brandon ◽  
Bryan Halliday ◽  
John S. Hoffman
Keyword(s):  
Air Temperature ◽  
Gas Turbines ◽  
Ambient Air ◽  
Business Case ◽  
Weather Data ◽  
Limiting Factor ◽  
Boost Pressure ◽  
Ambient Temperatures ◽  
Ambient Air Temperature ◽  
Field Deployment

The significant reduction in power output of small gas turbines at high ambient temperatures places the technology at a significant disadvantage compared with reciprocating engines. On site power applications in many jurisdictions are experiencing high power costs during summer peak times. A variable speed industrial fan combined with an evaporative cooler has been constructed and operated in the CETC laboratory in Ottawa, Canada to supply supercharged inlet air to a microturbine rated at 70 kW at ISO conditions. The supercharging system can raise the inlet air pressure by 10.5 kPa (42” wc). A mapping of the turbine performance has been done as a function of boost pressure, relative humidity and ambient air temperature. A net power increase has been observed from 57 kW to 70 kW at an ambient air temperature of 33°C (91°F) and RH of 60%, a 23% increase. Supercharging at lower temperatures yields lower net power increases since the microturbine generator rating is the limiting factor; for example an 11% increase in net power was observed at an inlet air temperature of 11°C (52°F) and RH of 60%. Supercharging was shown to decrease net fuel-to-electricity efficiency of this recuperated turbine by about 3%, at an air temperature of 33°C (91°F). An economic analysis using published power prices and weather data from Toronto explores the business case of using supercharging, with the best economies likely for multiple units or larger microturbines, such as 250 kW units. The objective of the project was to demonstrate the concept leading to a field trial in Toronto or in Calgary where the altitude offers a further benefit to the inlet air supercharging concept. Work is underway to design a control system suitable for field deployment for the concept.

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.

Implications of Thermal Discharge Limits on Future Power Generation in Texas

2013 ◽  
Author(s):  
Margaret A. Cook ◽  
Carey W. King ◽  
Michael E. Webber
Keyword(s):  
Thermoelectric Power ◽  
Air Temperature ◽  
Electricity Generation ◽  
Power Plants ◽  
Cooling Water ◽  
Ambient Air ◽  
Thermal Discharge ◽  
Ambient Air Temperature ◽  
Thermal Effluent ◽  
Thermoelectric Power Plants

The recent drought in Texas revealed the vulnerability of curtailment for some power plants due to cooling water supplies being too hot. Assessing the risk of reduced operations at thermoelectric power plants associated with thermal discharge limits, as well the potential for cooperation between power plants, can increase the resiliency of the electricity grid in Texas and aid future planning. This evaluation compares the observed effluent discharge water temperatures from thermoelectric power plants in the Electric Reliability Council of Texas (ERCOT) interconnection with Environmental Protection Agency (EPA) discharge temperature limits. Results indicate that at least two major power plants representing over 3,000 MW of cumulative generation capacity have operated at or near these temperature limits in the past. Predicted warming from heat waves, droughts, or climate change might increase ambient air temperature (one of the primary factors affecting effluent temperature) causing even higher derating in the future. We modeled current and future average monthly cooling water effluent temperature for open loop and recirculating cooling pond systems in ERCOT using current climate data and predictions of ambient air temperature, electricity generation, dew point, and wind speed for 2027–2032. While there are some power plants that are projected to be exposed to thermal effluent-related curtailment, we estimate that there is six times as much electricity generation potential available from other existing generators that can meet demand without reaching thermal effluent temperature limits. That is, this work’s analysis indicates that other existing power plants could generate additional electricity to offset the curtailment of the particular power plants at greatest risk from derating to maintain grid reliability.

Economic Evaluation on GTCC Inlet Air Cooling With Absorption Chiller

2005 ◽  
Author(s):  
Cheng Yang ◽  
Zeliang Yang ◽  
Ruixian Cai
Keyword(s):  
Economic Evaluation ◽  
Fuel Consumption ◽  
Output Power ◽  
Air Temperature ◽  
Cooling System ◽  
Ambient Air ◽  
Air Cooling ◽  
Absorption Chiller ◽  
Air Cooling System ◽  
Temperature Depression

Inlet air temperature increase results in a considerable reduction in GTCC power output. Present design of inlet air cooling system usually applied static method, which considered a constant depression of inlet air temperature, an approximate estimate of runtime, output power increase and fuel consumption variation per temperature depression, etc. However, to a crumb, at least another two problems should be studied. One is GTCC performance variation with inlet air temperature, since the kilowatt increment per centigrade is not a constant; the other is off design performance of inlet air cooling system, since the inlet air temperature depression through the cooling system varies with the actual operation conditions, such as ambient air temperature and cooling water temperature, etc. This paper presents an economic evaluation with numerical integration method on GTCC inlet air cooling with absorption chiller. For a typical GTCC composed of series E gas turbine and combined components, their non-dimensional performance curves are fitted with regression equations. Associating with these equations, the inlet air temperature characteristics of GTCC are simulated; and the fitted analytical expressions for GTCC inlet air temperature characteristics are also presented. The simulation method of off design performance of a typical absorption chiller is described. For a typical GTCC with inlet air cooling in south China area, integrated with the everyday typical weather data, GTCC everyday average output power and fuel consumption, output power increment and GTCC fuel consumption increment are simulated. The simulation results show that, for every 1°C depression in inlet air temperature, the GTCC output power increases 0.5%, while heat rate varies slightly and trends towards a rise at the inlet air temperature of about 15°C. Research on inlet air cooling scheme (Scheme 10°C, cooling the ambient air temperature from ambient temperature 30°C to 10°C) shows that, Scheme 10°C yields annual average 16°C of inlet air temperature depression. Economic evaluation based on numerical integration indicates that, in the case of Scheme 10°C, annual output power increases by 8.27%, fuel consumption rate increases by 1.03%; payback period approximately amounts to 2.0 years when power price is 12 cent/(kW.h) and fuel cost is $265/t.

scholarly journals The energy analysis of GE-F5 gas turbines inlet air–cooling systems by the off-design method

2019 ◽  
Vol 52 (9-10) ◽  
pp. 1489-1498
Author(s):  
Seyed Mehdi Arabi ◽  
Hossein Ghadamian ◽  
Mohammad Aminy ◽  
Hassan Ali Ozgoli ◽  
Behzad Ahmadi ◽  
...  
Keyword(s):  
Air Temperature ◽  
Gas Turbines ◽  
Design Method ◽  
Characteristic Curve ◽  
Air Cooling ◽  
Cooling Systems ◽  
Normal Cycle ◽  
Turbine Cooling ◽  
Efficiency Increase ◽  
Gas Power Plant

Increasing the inlet air temperature causes a reduction in the air mass flow rate, and the efficiency and output power of a gas power plant will reduced. To compensate this power and efficiency decrease, different cooling systems can be applied to the inlet air flow. This paper introduces and analyzes different gas turbine cooling systems and studies their effect on the efficiency of Zanbagh power plant’s G11 gas unit by extracting the governing equations regarding the characteristic curve and coding in the MATLAB software. In average, the simulation results show that reduction of 1 °C of inlet air temperature between 14 °C and 50 °C causes an efficiency and power output increase by 0.085% and 0.16 MW, respectively. The maximum cycle efficiency increase applied to cool the inlet air is around 2.7%, which can be achieved using the wet compression method. In addition, this method can reduce fuel consumption by 5% in comparison to a normal cycle.

Treatment of a Municipal Leachate Under Multi-Variable Conditions

1982 ◽  
Vol 17 (1) ◽  
pp. 135-148
Author(s):  
P.T. Wong ◽  
D.S. Mavinic
Keyword(s):  
Air Temperature ◽  
Nutrient Loading ◽  
Ambient Air ◽  
Removal Rates ◽  
Ambient Air Temperature

Abstract The treatability of a municipal leachate (BOD5 = 8090 mg/L) was investigated, by aerobic biostabilization, at a nutrient loading of BOD5:N:P of 100:3.2:1.1. The first stage effluents were subsequently polished by lime-magnesium coagulation. The ranges of ambient air temperature and sludge age studied were 5° to 25°C and 5 to 20 days, respectively. In the biostabilization phase, a BOD5:N:P loading of 100:3.2:1.1 was found to be “adequate” for treatment. Organic and metal removals in the first stage units were excellent. Under all conditions investigated, except for the two units close to washout conditions (5-day sludge age units at 5° and 10°C), BOD5 and COD removals of at least 99.4 and 96.4 percent, respectively, were achieved. Similarly, removal rates for most of the metals monitored were greater than 90 percent. In general, the removal of residual contaminants was not enhanced significantly by the addition of magnesium in the lime-magnesium polishing step.

scholarly journals Ambient Air Temperature Assisted Crystallization for Inorganic CsPbI2Br Perovskite Solar Cells

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3398
Author(s):  
Yi Long ◽  
Kun Liu ◽  
Yongli Zhang ◽  
Wenzhe Li
Keyword(s):  
Solar Cells ◽  
Air Temperature ◽  
High Performance ◽  
Defect Density ◽  
Perovskite Solar Cells ◽  
Ambient Air ◽  
Dark Phase ◽  
High Quality ◽  
Ambient Air Temperature ◽  
Air Atmosphere

Inorganic cesium lead halide perovskites, as alternative light absorbers for organic–inorganic hybrid perovskite solar cells, have attracted more and more attention due to their superb thermal stability for photovoltaic applications. However, the humid air instability of CsPbI2Br perovskite solar cells (PSCs) hinders their further development. The optoelectronic properties of CsPbI2Br films are closely related to the quality of films, so preparing high-quality perovskite films is crucial for fabricating high-performance PSCs. For the first time, we demonstrate that the regulation of ambient temperature of the dry air in the glovebox is able to control the growth of CsPbI2Br crystals and further optimize the morphology of CsPbI2Br film. Through controlling the ambient air temperature assisted crystallization, high-quality CsPbI2Br films are obtained, with advantages such as larger crystalline grains, negligible crystal boundaries, absence of pinholes, lower defect density, and faster carrier mobility. Accordingly, the PSCs based on as-prepared CsPbI2Br film achieve a power conversion efficiency of 15.5% (the maximum stabilized power output of 15.02%). Moreover, the optimized CsPbI2Br films show excellent robustness against moisture and oxygen and maintain the photovoltaic dark phase after 3 h aging in an air atmosphere at room temperature and 35% relative humidity (R.H.). In comparison, the pristine films are completely converted to the yellow phase in 1.5 h.

Evaluation of the influence of ambient air temperature and air velocity on mortar cement durability using a forced convection solar dryer

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Younes Bahammou ◽  
Mounir Kouhila ◽  
Haytem Moussaoui ◽  
Hamza Lamsyehe ◽  
Zakaria Tagnamas ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Forced Convection ◽  
Air Temperature ◽  
Building Materials ◽  
Ambient Air ◽  
Physical Significance ◽  
Drying Process ◽  
Air Velocity ◽  
Content Type ◽  
Ambient Air Temperature

PurposeThis work aims to study the hydrothermal behavior of mortar cement toward certain environmental factors (ambient air temperature and air velocity) based on its drying kinetics data. The objective is to provide a better understanding and controlling the stability of mortar structures, which integrate the sorption phenomenon, drying process, air pressure and intrinsic characteristics. This leads to predict the comportment of mortar structures in relation with main environmental factors and minimize the risk of cracking mortar structures at an early age.Design/methodology/approachThermokinetic study was carried out in natural and forced convection solar drying at three temperatures 20, 30 and 40°C and three air velocities (1, 3 and 5 m.s-1). The empirical and semiempirical models tested successfully describe the drying kinetics of mortar. These models simulate the drying process of water absorbed by capillarity, which is the most common humidity transfer mechanism in building materials and contain parameters with physical significance, which integrate the effect of several environmental factors and intrinsic characteristics of mortar structures.FindingsThe models simulate the drying process of water absorbed by capillarity, which is the most common humidity transfer mechanism in building materials and contain parameters with physical significance, which integrate the effect of several environmental factors and intrinsic characteristics of mortar structures. The average activation energy obtained expressed the temperature effect on the mortar diffusivity. The drying constant and the diffusion coefficient can be used to predict the influence of these environmental factors on the drying behavior of various building materials and therefore on their durability.Originality/valueEvaluation of the effect of several environmental factors and intrinsic characteristics of mortar structures on their durability.

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