Test Results From the Advanced Humid Air Turbine System Pilot Plant: Part 2—Humidification, Water Recovery and Water Quality

2008 ◽  
Author(s):  
Hidefumi Araki ◽  
Shinichi Higuchi ◽  
Tomomi Koganezawa ◽  
Shinya Marushima ◽  
Shigeo Hatamiya ◽  
...  
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Pilot Plant ◽  
Cooling System ◽  
Water Recovery ◽  
Humid Air ◽  
Circulating Water ◽  
Air Turbine ◽  
Recovery System ◽  
Calculation Results

The AHAT (advanced humid air turbine) system has been studied to improve thermal efficiency of gas turbine power generation. This is an original gas turbine power generation system which substitutes the WAC (water atomization cooling) system for the intercooler system of the HAT cycle. A pilot plant was built to verify feasibility of the AHAT system, which is composed of a gas turbine, a humidification tower, a recuperator and a water recovery system. Firstly, characteristics of the humidification tower were examined. The experimental results of the humidification rate agreed with the calculation results within a deviation of 1%. Humidification increased the heat recovery, and the electrical efficiency exceeded 40%. Secondly, characteristics of the spray-type water recovery system were examined. 95% of water consumed by the humidification tower was recovered, and a significant reduction of the make-up water for the HAT cycle was confirmed. Thirdly, concentrations of impurities within the circulating water of the AHAT system were measured when the recovered water was recycled without any purification process.

Performance Analysis of a 40mw Class Advanced Humid Air Turbine Pilot Plant

2013 ◽  
Author(s):  
Yutaka Watanabe ◽  
Toru Takahashi
Keyword(s):  
Gas Turbine ◽  
Pilot Plant ◽  
Gas Turbines ◽  
Power Plants ◽  
Medium Size ◽  
Water Recovery ◽  
Humid Air ◽  
System A ◽  
Air Turbine ◽  
Operational Test

Recently, high efficiency and operational flexibility are required for thermal power plants to reduce CO2 emissions and to introduce renewable energy sources. We study the advanced humid air turbine (AHAT) system, which appears to be high suitable for practical use because its configuration is simpler than that of gas turbine combined cycle power plants (GTCCs). Moreover, the thermal efficiency of AHAT system for small and medium-size gas turbines is higher than that of GTCCs. To verify feasibility of this system and the cycle performance of AHAT system, a 3MW-class pilot plant was built in 2006 by Hitachi, Ltd., which mainly consists of a gas turbine, a water atomization cooling (WAC) system, a recuperator, a humidification tower and a water recovery tower. Through the operational test from 2006 to 2010, we confirmed the feasibility of the AHAT as a power-generation system, and various characteristics such as the effect of changes in ambient temperature, part-load characteristics, and start-up characteristics. Next step, a 40MW-class pilot plant was built in 2011 and started operational tests. This system mainly consists of a dual-shaft heavy duty gas turbine, a WAC system, a recuperator and a humidifier. As a result of the operational test, it has been confirmed that the pilot plant output achieved rated power output. In this paper, we show the 40MW-class pilot plant running test results, and evaluate thermal characteristics of this plant and the effect of WAC and humidification on performance of this gas turbine system.

Development of Elemental Technologies for Advanced Humid Air Turbine System

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Hidetoshi Kuroki ◽  
Shigeo Hatamiya ◽  
Takanori Shibata ◽  
Tomomi Koganezawa ◽  
Nobuaki Kizuka ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pilot Plant ◽  
Pressure Ratio ◽  
High Humidity ◽  
Nox Emissions ◽  
Two Stage ◽  
Humid Air ◽  
Air Turbine ◽  
Recovery System

The advanced humid air turbine (AHAT) system improves the thermal efficiency of gas turbine power generation by using a humidifier, a water atomization cooling (WAC) system, and a heat recovery system, thus eliminating the need for an extremely high firing temperature and pressure ratio. The following elemental technologies have been developed to realize the AHAT system: (1) a broad working range and high-efficiency compressor that utilizes the WAC system to reduce compression work, (2) turbine blade cooling techniques that can withstand high heat flux due to high-humidity working gas, and (3) a combustor that achieves both low NOx emissions and a stable flame condition with high-humidity air. A gas turbine equipped with a two-stage radial compressor (with a pressure ratio of 8), two-stage axial turbine, and a reverse-flow type of single-can combustor has been developed based on the elemental technologies described above. A pilot plant that consists of a gas turbine generator, recuperator, humidification tower, water recovery system, WAC system, economizer, and other components is planned to be constructed, with testing slated to begin in October 2006 to validate the performance and reliability of the AHAT system. The expected performance is as follows: thermal efficiency of 43% (LHV), output of 3.6MW, and NOx emissions of less than 10ppm at 15% O2. This paper introduces the elemental technologies and the pilot plant to be built for the AHAT system.

Development of Elemental Technologies for Advanced Humid Air Turbine System

2006 ◽  
Author(s):  
Hidetoshi Kuroki ◽  
Takanori Shibata ◽  
Tomomi Koganezawa ◽  
Nobuaki Kizuka ◽  
Shigeo Hatamiya ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pilot Plant ◽  
Pressure Ratio ◽  
High Humidity ◽  
Nox Emissions ◽  
Two Stage ◽  
Humid Air ◽  
Air Turbine ◽  
Recovery System

The Advanced Humid Air Turbine (AHAT) system improves the thermal efficiency of gas turbine power generation by using a humidifier, a Water Atomization Cooling (WAC) system, and a heat recovery system, thus eliminating the need for an extremely high firing temperature and pressure ratio. The following elemental technologies have been developed to realize the AHAT system: (1) a broad working range and high-efficiency compressor that utilizes the WAC system to reduce compression work, (2) turbine blade cooling techniques that can withstand high heat flux due to high-humidity working gas, and (3) a combustor that achieves both low NOx emissions and a stable flame condition with high-humidity air. A gas turbine equipped with a two-stage radial compressor (with a pressure ratio of 8), two-stage axial turbine, and a reverse-flow type of single-can combustor has been developed based on the elemental technologies described above. A pilot plant that consists of a gas turbine generator, recuperator, humidification tower, water recovery system, WAC system, economizer, and other components is planned to be constructed, with testing slated to begin in October 2006 to validate the performance and reliability of the AHAT system. The expected performance is as follows: thermal efficiency of 43% (LHV), output of 3.6 MW, and NOx emissions of less than 10 ppm at 15% O2. This paper introduces the elemental technologies and the pilot plant to be built for the AHAT system.

Test Results From the Advanced Humid Air Turbine System Pilot Plant: Part 1—Overall Performance

2008 ◽  
Author(s):  
Shinichi Higuchi ◽  
Tomomi Koganezawa ◽  
Yasuhiro Horiuchi ◽  
Hidefumi Araki ◽  
Takanori Shibata ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pilot Plant ◽  
Pressure Ratio ◽  
High Humidity ◽  
Water Recovery ◽  
Two Stage ◽  
Humid Air ◽  
Air Turbine ◽  
Overall Performance

The AHAT (advanced humid air turbine) system is based on a recuperated cycle using high-humidity air. This system improves thermal efficiency by using the high-humidity air as working gas. After many studies and elemental tests, a 4MW-class pilot plant was planned and built in order to verify feasibility of the AHAT system from the viewpoints of heat cycle characteristic and engineering. This plant consists of a gas turbine, a recuperator, a humidification tower, a water recovery system, an economizer, and other components. The gas turbine consists of a two-stage centrifugal compressor (pressure ratio of 8), a reverse-flow type single-can combustor, and a two-stage axial-flow turbine. In overall performance tests, the plant thermal efficiency exceeded 40%LHV.

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.

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.

Study of Humid Air Gas Turbine System by Experiment and Analysis

2011 ◽  
Author(s):  
Toru Takahashi ◽  
Yutaka Watanabe ◽  
Hidefumi Araki ◽  
Takashi Eta
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pilot Plant ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Medium Size ◽  
Water Recovery ◽  
Two Stage ◽  
Humid Air

Humid air gas turbine systems that are regenerative cycle using humidified air can achieve higher thermal efficiency than gas turbine combined cycle power plant (GTCC) even though they do not require a steam turbine, a high combustion temperature, or a high pressure ratio. In particular, the advanced humid air gas turbine (AHAT) system appears to be highly suitable for practical use because its composition is simpler than that of other systems. Moreover, the difference in thermal efficiency between AHAT and GTCC is greater for small and medium-size gas turbines. To verify the system concept and the cycle performance of the AHAT system, a 3MW-class pilot plant was constructed that consists of a gas turbine with a two-stage centrifugal compressor, a two-stage axial turbine, a reverse-flow-type single-can combustor, a recuperator, a humidification tower, a water recovery tower, and other components. As a result of an operation test, the planned power output of 3.6MW was achieved, so that it has been confirmed the feasibility of the AHAT as a power-generating system. In this study, running tests on the AHAT pilot plant is carried out over one year, and various characteristics such as the effect of changes in ambient temperature, part-load characteristics, and start-up characteristics were clarified by analyzing the data obtained from the running tests.

Test Results of 40MW-Class Advanced Humid Air Turbine and Exhaust Gas Water Recovery System

2014 ◽  
Author(s):  
Takuya Takeda ◽  
Hidefumi Araki ◽  
Yasushi Iwai ◽  
Tetsuro Morisaki ◽  
Kazuhiko Sato
Keyword(s):  
Gas Turbine ◽  
Test Facility ◽  
Nox Emissions ◽  
Exhaust Gas ◽  
Water Recovery ◽  
Test Results ◽  
Operational Flexibility ◽  
Start Up ◽  
Air Turbine ◽  
Recovery System

Operational flexibility, such as faster start-up time or faster load change rate, and higher thermal efficiency, have become more and more important for recent thermal power systems. The advanced humid air turbine (AHAT) system has been studied to improve operational flexibility and thermal efficiency of gas turbine power generation systems. A 40MW-class AHAT test facility was built and the rated output was achieved. Through operations at the facility, it has been verified for the first time that the key components of the medium-class gas turbines, such as an axial compressor and multi-can combustor, can be applied to the AHAT system. The cold start-up time from ignition to rated power was about 60 min, which is approximately one-third that of a conventional gas turbine combined cycle (GTCC) plant. NOx emissions were 24ppm (at 16% O2) when the humidity of combustion air was approximately a half that of present commercial AHAT plants, and NOx emissions in a future commercial AHAT system were thought to be less than 10ppm. A water recovery system which recovers water from a part of the exhaust gas of the 40MW-class test facility was built and test operations were made from June 2013. In this paper, water recovery test results as well as the 40MW-class gas turbine test results are shown.

scholarly journals Humid Air Turbine Cycles With Water Recovery: How to Dispose Heat in an Efficient Way

1998 ◽  
Author(s):  
Umberto Desideri ◽  
Francesco Di Maria
Keyword(s):  
Flue Gas ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Plant Performance ◽  
Water Recovery ◽  
Humid Air ◽  
Air Turbine ◽  
Recovery System ◽  
Additional Costs ◽  
Original Configuration

Since the humid air turbine (HAT) cycle was first presented by Rao and Joiner (1990), several modifications were proposed to the original configuration to further improve its efficiency. In the last years, the attention was focused in the water recovery from flue gas and in determining the most suitable systems to separate water from gas and solving the problem of low temperature at the stack. In all the above studies it was shown that condensing water from flue gas requires a significant flow rate of a cooling medium (generally water) which is needed to remove condensation heat which must then be disposed in the environment. This worsens power plant performance because large cooling towers are needed. On the other hand, the reduced cost of water treatment may compensate the additional costs of the condensation equipment. In this paper, the introduction of an Organic Rankine Cycle (ORC), which transforms in mechanical power a fraction of the heat recovered from the HAT cycle, both in the water recovery system and in other heat exchangers, is presented. Results were obtained by using three different fluids and maximizing the ORC input exergy. The substances which were used are the conventional R502 refrigerant fluid, ammonia and the new HF134a, which is replacing phased-out CFCs in refrigeration systems.

Thermo-Economic Evaluation of Bio-Ethanol Humidification EvGT Cycle

2005 ◽  
Author(s):  
Marcus Thern ◽  
Torbjo¨rn Lindquist ◽  
Tord Torisson
Keyword(s):  
Gas Turbine ◽  
Equilibrium Model ◽  
Pilot Plant ◽  
Rankine Cycle ◽  
Outlet Temperature ◽  
Humid Air ◽  
Power Cycles ◽  
Air Stream ◽  
Air Turbine ◽  
Institute Of Technology

The evaporative gas turbine pilot plant (EvGT) has been in operation at Lund Institute of Technology in Sweden since 1997. This article presents the latest development in the evaporative technology, the evaporation of bio-ethanol in a gas turbine power plant as a means to reduce the emission of greenhouse gases. Bio-ethanol is produced from a feedstock consisting of corn-stover, and the bio-ethanol is here considered to be a renewable fuel with zero impact regarding CO2 in the exhaust gases. This concept is evaluated and compared to a direct-fired Rankine cycle in the size range of 3–5 MWel and 15–30 MWel concerning plant efficiency and investment cost. The proposed bio-ethanol evaporation technology provides fuel for a Humid Air Turbine by evaporating bio-ethanol into the compressor discharge air. This evaporation process creates a combustible gas that is led to the combustor as the primary fuel. The bio-ethanol used in the process has not been distilled. The bio-ethanol is supplied to the process as a mash, i.e. a mix of water and ethanol with low concentration of ethanol. To extract the ethanol from the mash, energy is required. In this process, low-level heat from the gas turbine cycle is used for the separation process. All power cycles studied have been modeled in IPSEpro™, a heat and mass balance software, using advanced component models developed by the authors. An equilibrium model is used to model the behavior of the evaporation of ethanol and water into an air stream. A correction parameter has been introduced into the equilibrium model to account for the deviation from equilibrium. This parameter has been validated through experimental work on the Evaporative Gas Turbine pilot plant. The evaporation technology can be used with different types of cycle configurations attaining electrical efficiencies of 29% for a simple version of a Humid Air Turbine. The Humid Air Turbine can sustain a combustor outlet temperature of 1100°C without supplementary firing. The proposed cycle configuration also shows to be an economically viable alternative to direct fired Rankine cycle.

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