System Optimization of Humid Air Turbine Cycle

1994 ◽  
Author(s):  
Yunhan Xiao ◽  
Rumou Lin ◽  
Ruixian Cai
Keyword(s):  
High Efficiency ◽  
Pressure Ratio ◽  
System Optimization ◽  
Combined Cycle ◽  
Parameter Analysis ◽  
Specific Power ◽  
Design Parameters ◽  
Humid Air ◽  
Systems Research ◽  
Air Turbine

The humid air turbine (HAT) cycle, proposed by Mori et al. and recently developed by Rao et al. at Flour Daniel, has been identified as a promising way to generate electric power at high efficiency, low cost and simple system relative to combined cycle and steam injection gas turbine cycle. It has aroused considerable interest. Thermodynamic means, such as intercooling, regeneration, heat recovery at low temperature and especially non-isothermal vaporisation by multi-phase and multi-component, are adopted in HAT cycle to reduce the external and internal exergy losses relative to the energy conversion system. In addition to the parameter analysis and the technical aspect of HAT cycle, there is also a strong need for “systems” research to identify the best ways, of configuring HAT cycle to integrate all the thermodynamic advantages more efficiently to achieve high performance. The key units in HAT cycle are analyzed thermodynamically and modelled in this paper. The superstructure containing all potentially highly efficient flowsheeting alternatives is also proposed. The system optimization of the HAT cycle is thus represented by a nonlinear programming problem. The problem is solved automatically by a successive quadratic algorithm to select the optimal configuration and optimal design parameters for the HAT cycle. The results have shown that the configuration of the HAT cycle currently adopted is not optimal for efficiency and/or specific power, and the current pressure ratio are too high to be favorable for highest performance. Based on the current technical practice, the optimal flowsheeting for thermal efficiency can reach 60.33% when TIT=1533K, while the optimal flowsheeting for specific power can achieve 1300kW/kg/s air for TIT at 1533K. The optimal flowsheeting configuration is compared favorably with the other existing ones.

Design Study of a Humidification Tower for the Advanced Humid Air Turbine System

2005 ◽  
Author(s):  
Hidefumi Araki ◽  
Shinichi Higuchi ◽  
Shinya Marushima ◽  
Shigeo Hatamiya
Keyword(s):  
Gas Turbine ◽  
Heat Exchangers ◽  
High Efficiency ◽  
Cooling System ◽  
Pressure Ratio ◽  
Humid Air ◽  
Air Turbine ◽  
Water Atomization ◽  
Air Cooler ◽  
Compressor Work

The AHAT (advanced humid air turbine) system, which can be equipped with a heavy-duty, single-shaft gas turbine, aims at high efficiency equal to that of the HAT system. Instead of an intercooler, a WAC (water atomization cooling) system is used to reduce compressor work. The characteristics of a humidification tower (a saturator), which is used as a humidifier for the AHAT system, were studied. The required packing height and the exit water temperature from the humidification tower were analyzed for five virtual gas turbine systems with different capacities (1MW, 3.2MW, 10MW, 32MW and 100MW) and pressure ratios (π = 8, 12, 16, 20 and 24). Thermal efficiency of the system was compared with that of a simple cycle and a recuperative cycle with and without the WAC system. When the packing height of the humidification tower was changed, the required size varied for the three heat exchangers around the humidification tower (a recuperator, an economizer and an air cooler). The packing height with which the sum total of the size of the packing and these heat exchangers became a minimum was 1m for the lowest pressure ratio case, and 6m for the highest pressure ratio case.

Energy Analysis of Part Flow and Full Flow Humid Air Turbine Cycle (HAT)

2006 ◽  
Author(s):  
Vahid Noei Aghaei ◽  
Bahador Bakhtiari ◽  
Hiwa Khaledi ◽  
Mohammad Bagher Ghofrani
Keyword(s):  
Thermodynamic Model ◽  
Energy Analysis ◽  
Pressure Ratio ◽  
Great Influence ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Water Mixture ◽  
Humid Air ◽  
Air Turbine

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.

scholarly journals Humid Air Gas Turbine Cycle: A Possible Optimization

1993 ◽  
Author(s):  
S. S. Stecco ◽  
U. Desideri ◽  
N. Bettagli
Keyword(s):  
Relative Humidity ◽  
Water Consumption ◽  
Compression Ratio ◽  
High Efficiency ◽  
Power Production ◽  
Specific Power ◽  
Humid Air ◽  
Air Turbine ◽  
High Specific Power ◽  
Gas Turbine Cycle

The humid air turbine (HAT), patented by Fluor Daniel, is an innovative cycle which allows to obtain an increase in efficiency and power production. The modification proposed by DEF allows to optimise the plant when natural gas is injected in the combustion chamber. Assuming a TIT (Temperature Inlet Turbine) at 1273 K and the cooling of recirculating water in the refrigerators, we studied the effects of the relative humidity and the compression ratio on the cycle’s performances. The aim of this paper is to suggest the parameters which allow to obtain high efficiency with high specific power, the possibility to modulate power production without a decrease in efficiency and low water consumption.

scholarly journals Semi Closed Gas Turbine Cycle and Humid Air Turbine: Thermoeconomic Evaluation of Cycle Performance and of the Water Recovery Process

1998 ◽  
Author(s):  
Andrea Corti ◽  
Bruno Facchini ◽  
Giampaolo Manfrida ◽  
Umberto Desideri
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Recovery Process ◽  
Plant Size ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Specific Power ◽  
Water Recovery ◽  
Humid Air ◽  
Air Turbine

A comparison between power plants built according to the HAT (Humid Air Turbine) and SCGT/CC (Semi-Closed Gas Turbine/Combined Cycle) concepts is presented, ranging from thermodynamic performance (efficiency and specific power output) to projected data for plant construction and operating costs. Both options appear to be of potential interest to electric utilities considering advanced gas turbine power plants, with significant differences form the point of view of plant size, water consumption, and adaptability to advanced developments for the limitation of environmental impact (CO2 emissions).

Design Study of a Humidification Tower for the Advanced Humid Air Turbine System

2005 ◽  
Vol 128 (3) ◽  
pp. 543-550 ◽  
Author(s):  
Hidefumi Araki ◽  
Shinichi Higuchi ◽  
Shinya Marushima ◽  
Shigeo Hatamiya
Keyword(s):  
Gas Turbine ◽  
Heat Exchangers ◽  
High Efficiency ◽  
Cooling System ◽  
Pressure Ratio ◽  
Humid Air ◽  
Air Turbine ◽  
Water Atomization ◽  
Air Cooler ◽  
Compressor Work

The advanced humid air turbine (AHAT) system, which can be equipped with a heavy-duty, single-shaft gas turbine, aims at high efficiency equal to that of the HAT system. Instead of an intercooler, a WAC (water atomization cooling) system is used to reduce compressor work. The characteristics of a humidification tower (a saturator), which is used as a humidifier for the AHAT system, were studied. The required packing height and the exit water temperature from the humidification tower were analyzed for five virtual gas turbine systems with different capacities (1, 3.2, 10, 32, and 100MW) and pressure ratios (π=8, 12, 16, 20, and 24). Thermal efficiency of the system was compared with that of a simple cycle and a recuperative cycle with and without the WAC system. When the packing height of the humidification tower was changed, the required size varied for the three heat exchangers around the humidification tower (a recuperator, an economizer, and an air cooler). The packing height with which the sum total of the size of the packing and these heat exchangers became a minimum was 1m for the lowest pressure ratio case, and 6m for the highest pressure ratio case.

Progress of the 40 MW-Class Advanced Humid Air Turbine Tests

2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Manabu Yagi ◽  
Hidefumi Araki ◽  
Hisato Tagawa ◽  
Tomomi Koganezawa ◽  
Chihiro Myoren ◽  
...  
Keyword(s):  
Metal Surface ◽  
Control Method ◽  
Cooling System ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Test Facility ◽  
Humid Air ◽  
Air Turbine ◽  
Calculation Results ◽  
Flow Compressor

A 40 MW-class test facility has been constructed to verify practicability of applying the advanced humid air turbine (AHAT) system to a heavy-duty gas turbine. Verification tests have been carried out from January 2012, and interaction effects between the key components were established. First, water atomization cooling (WAC) was confirmed to contribute to both increased mass flow rate and pressure ratio for the axial-flow compressor. The good agreement between measured and calculated temperatures at the compressor discharge was also confirmed. These results demonstrated the accuracy of the developed prediction model for the WAC. Second, a control method that realized both flame stability and low nitrogen oxides (NOx) emissions was verified. Although the power output and air humidity were lower than the rated values, NOx concentration was about 10 ppm. Finally, a hybrid nozzle cooling system, which utilized both compressor discharged air and humid air, was developed and tested. The metal surface temperatures of the first stage nozzles were measured, and they were kept under the permissible metal temperature. The measured temperatures on the metal surface reasonably corresponded with calculation results.

Impact of Inlet Fogging on the Performance of Steam Injected Cooled Gas Turbine Based Combined Cycle Power Plant

2017 ◽  
Author(s):  
Anoop Kumar Shukla ◽  
Onkar Singh
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Film Cooling ◽  
Pressure Ratio ◽  
Steam Injection ◽  
Combined Cycle ◽  
Specific Power ◽  
Temperature Cycle ◽  
Inlet Temperature ◽  
Combined Cycle Power Plant

Gas/steam combined cycle power plants are extensively used for power generation across the world. Today’s power plant operators are persistently requesting enhancement in performance. As a result, the rigour of thermodynamic design and optimization has grown tremendously. To enhance the gas turbine thermal efficiency and specific power output, the research and development work has centered on improving firing temperature, cycle pressure ratio, adopting improved component design, cooling and combustion technologies, and advanced materials and employing integrated system (e.g. combined cycles, intercooling, recuperation, reheat, chemical recuperation). In this paper a study is conducted for combining three systems namely inlet fogging, steam injection in combustor, and film cooling of gas turbine blade for performance enhancement of gas/steam combined cycle power plant. The evaluation of the integrated effect of inlet fogging, steam injection and film cooling on the gas turbine cycle performance is undertaken here. Study involves thermodynamic modeling of gas/steam combined cycle system based on the first law of thermodynamics. The results obtained based on modeling have been presented and analyzed through graphical depiction of variations in efficiency, specific work output, cycle pressure ratio, inlet air temperature & density variation, turbine inlet temperature, specific fuel consumption etc.

Performance Evaluation of a Small Scale High Efficiency Cogeneration System

2006 ◽  
Author(s):  
Mauro Reini
Keyword(s):  
High Efficiency ◽  
Pressure Ratio ◽  
Organic Rankine Cycle ◽  
Thermodynamic Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Working Fluid ◽  
Small Scale ◽  
Performance Parameters ◽  
Cogeneration System

In recent years, a big effort has been made to improve microturbines thermal efficiency, in order to approach 40%. Two main options may be considered: i) a wide usage of advanced materials for hot ends components, like impeller and recuperator; ii) implementing more complicated thermodynamic cycle, like combined cycle. In the frame of the second option, the paper deals with the hypothesis of bottoming a low pressure ratio, recuperated gas cycle, typically realized in actual microturbines, with an Organic Rankine Cycle (ORC). The object is to evaluate the expected nominal performance parameters of the integrated-combined cycle cogeneration system, taking account of different options for working fluid, vapor pressure and component’s performance parameters. Both options of recuperated and not recuperated bottom cycles are discussed, in relation with ORC working fluid nature and possible stack temperature for microturbine exhaust gases. Finally, some preliminary consideration about the arrangement of the combined cycle unit, and the effects of possible future progress of gas cycle microturbines are presented.

Development of an 8MW-Class High-Efficiency Gas Turbine, M7A-03

2007 ◽  
Author(s):  
Kazuhiko Tanimura ◽  
Naoki Murakami ◽  
Akinori Matsuoka ◽  
Katsuhiko Ishida ◽  
Hiroshi Kato ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
High Performance ◽  
High Efficiency ◽  
High Reliability ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Gas Temperature ◽  
Turbine Cooling ◽  
Distributed Power Generation

The M7A-03 gas turbine, an 8 MW class, single shaft gas turbine, is the latest model of the Kawasaki M7A series. Because of the high thermal efficiency and the high exhaust gas temperature, it is particularly suitable for distributed power generation, cogeneration and combined-cycle applications. About the development of M7A-03 gas turbine, Kawasaki has taken the experience of the existing M7A-01 and M7A-02 series into consideration, as a baseline. Furthermore, the latest technology of aerodynamics and cooling design, already applied to the 18 MW class Kawasaki L20A, released in 2000, has been applied to the M7A-03. Kawasaki has adopted the design concept for achieving reliability within the shortest possible development period by selecting the same fundamental engine specifications of the existing M7A-02 – mass air flow rate, pressure ratio, TIT, etc. However, the M7A-03 has been attaining a thermal efficiency of greater than 2.5 points higher and an output increment of over 660 kW than the M7A-02, by the improvement in aerodynamic performance of the compressor, turbine and exhaust diffuser, improved turbine cooling, and newer seal technology. In addition, the NOx emission of the combustor is low and the M7A-03 has a long service life. These functions make long-term continuous operation possible under various environmental restraints. Lower life cycle costs are achieved by the engine high performance, and the high-reliability resulting from simple structure. The prototype M7A-03 gas-turbine development test started in the spring of 2006 and it has been confirmed that performance, mechanical characteristics, and emissions have achieved the initial design goals.

Combined Cycle Engine Cascades Achieving High Efficiency

2016 ◽  
Author(s):  
Andy Schroder ◽  
Mark G. Turner ◽  
Rory A. Roberts
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Fuel Cell ◽  
Supercritical Carbon Dioxide ◽  
High Efficiency ◽  
Waste Heat ◽  
Combined Cycle ◽  
Design Parameters ◽  
Topping Cycle ◽  
Supercritical Carbon

Two combined cycle engine cascade concepts are presented in this paper. The first uses a traditional open loop gas turbine engine (Brayton cycle) with a combustor as the topping cycle and a series of supercritical carbon dioxide (S–CO2) engines as intermediate cycles and a bottoming cycle. A global optimization of the engine design parameters was conducted to maximize the combined efficiency of all of the engines. A combined cycle efficiency of 65.0% is predicted. The second combined cycle configuration utilizes a fuel cell inside of the topping cycle in addition to a combustor. The fuel cell utilizes methane fuel. The waste heat from the fuel cell is used to heat the high pressure air. A combustor is also used to burn the excess fuel not usable by the fuel cell. After being heated, the high pressure, high temperature air expands through a turbine to atmospheric pressure. The low pressure, intermediate temperature exhaust air is then used to power a cascade of supercritical carbon dioxide engines. A combined efficiency of 73.1% using the fuel lower heating value is predicted with this combined fuel cell and heat engine device. Details of thermodynamics as well as the (S–CO2) engines are given.

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