A PVT measurement apparatus by the Burnett method for the temperature range from room temperature to 250 ℃ and at pressures up to 100 MPa has been developed with a remote operation system. PVT measurements of hydrogen, helium and nitrogen have been accomplished up to 97 MPa. The density uncertainty of the present measurements at 80 ℃ is estimated to be 0.2 % from the deviations for nitrogen. An existing equation of state (EOS) for hydrogen agrees well with the present measurements within ±0.22 % at 80 ℃. The systematic deviations between the EOS and the present measurements at 120 ℃ and 160 ℃ are shown with the maximum deviation of 0.52 % at 120 ℃ and 97 MPa.

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The present study discusses the heat and reaction characteristics of the multistage alcoholic-fuel reformer. Gas temperatures, exhaust gas components and radical chemiluminescence intensities were monitored in the reformer. In the single-stage case, temperature level inside the reactor and decomposition ratio of CH_3OH, a, were decreased with an increase in equivalence ratio, φ (≥3.0). In contrast, higher φ resulted in lower OH-radical chemiluminescence intensity inside the reactor. In the double-stage case that a portion of the air was supplied to the secondary port, a slight increase in the H_2 concentration was observed, and an excessive increase of local temperature was avoided. These results show the double-stage air supply is effective to control the temperature distribution and avoid an undesired hot-spot in the reformer without causing a significant change in the components of the product gas.

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The concept of using CO_2 as a gasification medium has been investigated both theoretically and experimentally. The theoretical investigation was done using Aspen[○!R] Plus simulations to explore and understand the impact of CO_2 on an integrated gasification combined cycle (IGCC) plant and the gasifier performance. The results show that a steam to carbon ratio of 1.5 provides a hydrogen output from the gasifier of 1.15 kg hr^<-1> while generating about 14 kW of electricity per kmol hr^<-1> of carbon from a SOFC using the portion of the CO generated that was not needed to drive the reforming reactions. However recycling up to 25% of CO_2 into the gasifier produces about 15% more hydrogen, while using 20% less CO for combustion to drive the gasification reactions. The IGCC simulations show that the addition of CO_2, from the high pressure compressor, does not change the CGE. The baseline CGE using steam gasification of Spring Creek coal (9338 BTU lb^<-1>) is 65.0% whereas replacing the steam with CO_2 resulted in a CGE of 65.1%. Moreover, the H_2O/CO was reduced from 4.2 for steam gasification to 2.0 for CO_2 gasification, which is the minimum necessary to enable efficient operation of water gas shift reactors. Validation tests over a CO_2 concentration range from 0% to 100% by volume resulted in a significant enhancement in the CO evolution above 700℃. However the CO_2 introduction suppressed the H_2 production at temperatures above 700℃, indicating a delayed effect on H_2 suppression. All biomass test samples showed similar mass decay behavior and were completely exhausted by 900°-1000℃. Finally, CO_2 gasification of various biomass and municipal solid waste (MSW) feedstocks has yielded similar results to those obtained using coal.

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The biomass and waste are one of the renewable energy that expected to reduce the greenhouse gas emission into atmosphere, and the development of those utilization technologies is a pressing necessity. However, the biomass and waste resources are distributed wide and thinly, and the cost of collection and transportation is expensive. Then, CRIEPI has advanced the development of biomass/waste carbonizing gasification process for small-scale and high-effective power generation system. This process feature is to adopt the carbonizer as pretreatment equipment of the gasifier. A carbonizer makes it possible to use various biomasses and wastes with different chemical property as a fuel of the gasifier. In this paper, the carbonizing gasification test results of the oil-plant dregs (PKS; Palm Kernel Shell and JSD; Jatropha Seeds Dregs) and food processing waste (coffee dregs and beer dregs) are reported.

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The tar produced in the biomass gasification process had a bad effect on the whole gasification process flow. If the tar can be transformed into combustible gas before condensation, the gasification efficiency would be improved and the tar content would be decreased. This thesis built a tar catalytic cracking and removal process model of biomass rice straw pyrogenation and gasification by based on the analysis of factors influencing the tar catalytic cracking rate, and least squares support vector machine, and conducted the validation. On this basis, this thesis did an optimized calculation upon the parameters of the tar removal process. The results proved that this model had good generalization ability, fitting effect, and can simulate the characteristics of biomass rice straw catalytic `cracking process, and when the catalytic cracking temperature reached 937.0101℃ and the gas residence time was 0.9041 s, the maximum of the tar catalytic cracking rate can be 95.4418%.

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In expectation of mixing wood pellets in the fuel at Maizuru Power Plant Unit 1 ("Plant) at the Kansai Electric Power Co., Inc., we have been conducting tests using in-house testing equipment to determine pulverization and combustion characteristics of the wood pellets. As a result, the pellets' characteristics were successfully ascertained. In line with the upcoming commencement of mixed fuel operation, we have implemented trial runs at the Plant in an effort to establish a method for setting the maximum mixing ratio in a coal pulverizer with different coal properties, and to confirm the combustion characteristics and boiler heat absorption balance.

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We are imported over 90% primary energy resources from foreign countries in Japan. To keep the future electric power stable supply and to reduce the carbon dioxide emission, the development of the carbon dioxide reduction technology from the electric power generation systems is our urgent issue. The authors studied the technologies to capture the carbon dioxide from the exhaust gas and storage, and got the conclusion that it was theoretically possible, practically and economically unfeasible. To reduce the carbon dioxide, first it is necessary to improve the new power generating system's efficiency developing the more high-temperature gas turbine combined-cycle and coal gasification combined-cycle power generation systems. Secondly it is necessary to promote the carbon neutral biomass resources' use substituted for fossil resources. The BDF such as bio-ethane, fat acid ester etc. is combusted in the existing oil fired and natural gas fired power generation plats, and woody biomass and solid waste will be co-fired at the existing coal fired power generating plants. In near future, the construction of new power generating plants based on biomass co-firing technology will be necessary. In this paper the authors proposed two scenarios to achieve the carbon dioxide emission reduction from that of 1990 in 2050.

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A comprehensive CFD modeling study has been undertaken to investigate the co-firing of pulverized coal and biomass in a 150 kW_<Fuel> swirl-stabilized burner, which is similar in flow pattern to a typical low-NO_x burner. The objective of the present study is to derive a reliable modeling methodology for design and optimization of low NO_x burners co-firing pulverized coal and biomass. For this purpose, the effects of meshes, global reaction mechanisms for homogeneous combustion, turbulence models, turbulence-chemistry interactions, properties of the solid fuels, and solid-fuel particle conversion models are finely examined. The modeling results are compared with detailed mapping of molar fractions of main species, obtained from FT IR and a Horiba gas analyzer. This paper presents mainly the comparison of different global homogenous combustion mechanisms and different solid-fuel particle conversion models, in modeling of pulverized coal and biomass co-combustion.

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Urbanization development and sewage industry development have brought about a soaring increment of sewage sludge, how to dispose the ever-increasing sewage sludge and eliminate their hazard has become a serious problem with which people are currently confronted. The technologies of co-combustion of sewage sludge and coal can not only ease the problems in sewage sludge disposal in many big cities, but also can utilize the heat of waste sewage sludge for power generation. Based on the actual situation and need of the co-combustion of coal and sewage sludge in the power plant, one coal sample from a power plant and one sewage sludge sample from a sewage treatment plant were studied in this paper for the feasibility of co-combustion in the coal-fired power plant. Sewage sludge with different moisture contents and coal were mixed into different proportions. Thermal gravity analysis (TGA) and Drop Tube Furnace (DTF) experiments were used to study the characteristics of combustion, pollution gases emission and also heavy metal emission. It was found in this study that there was a comparatively large difference between combustion characteristics of sewage sludge and those of coal. However, the performance of co-combustion of sewage sludge with coal is generally expressing the joint action result of sewage sludge and coal, and sometimes better than the burning of single coal. This study will provide essential and fundamental research data for the feasibility and utilization of co-combustion of coal and sewage sludge in the power plant.

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Global warming is currently a key topic in international politics; therefore, the impact of measures taken to counteract it is enormous. However, it should be noted that considerable controversy surrounds the scientific truth on global warming. Therefore, clarifying the scientific truth is both urgent and crucial. To this end, the author, as vice chairman of the editorial committee of the Japan Society of Energy and Resources, coordinated an e-mail discussion among five prominent Japanese scientists. The full text in Japanese, including data forming the basis of the discussion, is available for download from the homepage of the Japan Society of Energy and Resources (http://www.jser.gr.jp/). To the author's knowledge, the discussion, supporting papers, and associated data represent the first trial of its kind. On the occasion of ICOPE-09, the coordinator summarizes the outline of the e-mail discussion and illustrates state-of-the-art research on global warming.

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Carbon dioxide (CO_2) ocean sequestration technologies, such as dissolution into seawater, are important to mitigate global warming. In this study, solution processes of CO_2 gas in seawater and synthetic seawater were experimentally and theoretically studied under various pressures and temperatures to evaluate the transport process of CO_2 in seawater. The solubilities of CO_2 in seawater and synthetic seawater were measured by a change in pressure due to absorption at pressures up to 3 MPa and the temperatures ranged from 276 K to 333 K. It was obtained that the solubilities of CO_2 increase with an increase in pressure, but decrease with an increase in temperature. The solubility of CO_2 in synthetic seawater decreases with an increase in salt concentration. Empirical correlations for solubilities of CO_2 in seawater at various temperatures and pressures were obtained based on the experimental data. In the theoretical analysis for the solution of single CO_2 bubble in seawater, the single CO_2 bubble was assumed to be stationary and surrounded by infinite liquid seawater. The rate of solution of bubble in liquid is affected strongly by various parameters, such as solubility, diffusion coefficient, bubble radius, and temperature.

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In this paper, several decarburization technologies of coal-fired power plant flue gas were reviewed. In general, major decarburization processes of coal-fired power plant flue gas as follow: adsorption, membrane separation, low-temperature separation and absorption separation. Main points and feasibility of those decarburization technologies were summarized. The research status of CO_2 removal of flue gas was presented, and the keystones of each research were summarized.

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Coal is the main fossil fuel of thermal power plants in China. CO_2 emission reduction is a key factor in supporting the continued use of fossil fuels, particularly coal consumption. Characteristics of coal-fired flue gas were presented, and four main technologies, solvent absorption, membranes, adsorption, and cryogenic were reviewed. With regard to the characteristics of each technology and coal combustion flue gas described in the above, chemical absorption process was regarded as the most promising to be put into large scale use. An aqueous ammonia based multi-pollutant control process for scrubbing SO_2, NOx, mercury, and CO_2 from flue gas was developed on the basis of relative literatures. The following advantages of the aqueous ammonia process over conventional amines were examined: lower heat requirement, more CO_2 absorption, lower chemical cost, and multi-pollutant control with by-products.

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The objective of the present study is to measure the CO_2 hydrate film thickness experimentally and predict the time transition of the hydrate film thickness by the analysis. In the experiment, the hydrate film thickness which forms at the interface between water and liquid CO_2 was measured by laser interference method. The hydrate film thickness was about 8 μm at 6 MPa and 7.1 ℃ with water flow adjacent to the hydrate film. The hydrate film thickness was about 13 pm at 6 MPa and 4.6 ℃ without water flow. In the analysis model, hydrate formation occurs at the interface between the liquid CO_2 and the hydrate due to the penetration of H_2O molecules through the hydrate film. Meanwhile hydrate dissolution occurs at the interface between the water and the hydrate due to the diffusion of CO_2 molecules to the water phase. The results indicate the film thickness decreases within several minutes, then increases.

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A novel power generation system with low carbon dioxide (CO_2) emission was proposed. Thermal stimulation method was selected to dissociate the oceanic methane hydrate. By means of process simulation, the feasibility of proposed system was confirmed. A power generation system with approximately 40% thermal efficiency and above 90% CO_2 recovery rate was achieved. In this system, CO_2 due to the combustion is recovered by compressed seawater. CO_2 dissolved seawater is heated by the exhausted gas and injected to the hydrate layer to dissociate the methane hydrate. CO_2 is sequestrated simultaneously. Moreover, in order to quantify the heat loss during the injection of hot seawater to the hydrate layer, numerical simulation of the internal pipe flow was conducted. It was shown that the seawater temperature at the pipe outlet can be evaluated by the pipe diameter, thermal conductivity and the thickness of the insulation material.

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Using laboratory-scale bubbling reactor, the relationship between desulfurization efficiency and several factors were studied, including flow rate of the simulated flue gas, concentration of magnesia absorbent and magnesium sulfate, concentration of sulfur dioxide in the flue gas, and temperature of the absorption liquid etc. With the parameters close to the practical conditions, the results indicated that the whole desulfurization process can be divided into two parts according to the pH value of absorption liquid. The efficiency improves with the increase of concentration of magnesia or magnesium sulfate, and decreases with the increase of flue gas flow rate or concentration of sulfur dioxide. The temperature has no obvious effect on the desulfurization efficiency. It can be concluded that magnesium desulfurization process is controlled by the mass transfer of sulfur dioxide at the gas-liquid interface, especially the chemical absorbent reaction in liquid film.

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Carbide slag and fly ash are the by-product of chemical engineering. This paper reports the dissolution process of mixed absorbents of carbide slag, fly ash, and limestone as wet absorbents. The reaction activity of single component of carbide slag or fly ash is better than the limestone. When limestone is mixed with carbide slag, the dissolution rate of the mixture increases with the increasing of carbide slag content. The reaction rate of fly ash is the fastest, and doesn't obviously change when the fly ash is mixed with carbide slag. The fly ash can be used as an additive to improve the reaction property of desulfurizers. The shrinking core model incorporated into particle size distribution is introduced to study the dissolution process of solid particle groups. The dissolution processes of three desulfurizers are predicted. And the reaction characteristics of desulfurizers can be described by a parameter called the total chemical reaction rate constant. This correlation model has a significant value for improving the liquid-solid reaction theory system. And it is helpful to obtain the micro chemical reaction parameters from the macro experimental data.

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According to the process of the wet FGD (Flue Gas Desulphurization) and the layout of the 2×350MW units, the paper creatively puts forward the design of a steel chimney located on the construction of the absorber. With STAAD. Pro software, the shell element analysis method is adopted for the analysis of the overall structural strength and stability, and the stiffening ribs are used to enhance the stability of the structure. The combined structure simplifies the process system of FGD and saves the area. For the old power plants which are required to install FGD, it is both effective and economical.

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The micro-grid has been operating at institute of technology of Shimizu Corporation since July, 2006. Main generators are two gas engine CHP (Combined Heat and Power) systems which rated output are 350kW and 90kW. Two power storage devices, a secondary battery and an electric double layer capacitor, are also installed to compensate rapid load fluctuation. This paper proposes an islanding operation control technique for these equipments using an integrated central control by central control server and an autonomous control of electric double layer capacitor. It is possible seamless operation transition between grid-connecting operation and islanding operation because condition signal of circuit breaker has transmitted to each generator at 30 milliseconds. We have verified validity of the developed control method by using the micro-grid. As the results of 50 times transition experiments, frequency fluctuation target (within 0.2 Hz) has been satisfied with probability 99.9 % and voltage fluctuation target (within 10 %) has been satisfied with probability 100.0 %.

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This paper presents practical distribution system equipment models such as various distributed generators, voltage regulators, and loads for fast three phase unbalanced load flow calculation in distribution systems. The method can calculate voltage and current of distribution systems, in which distributed generators are introduced. The calculation time of the proposed method is about 40 times faster than that of the Newton-Raphson method. Moreover, an introduction effect evaluation tool for distributed generators using the proposed three phase unbalanced load flow calculation is presented. It provides various functions such as power system network diagram creation function and voltage profile chart display function. Therefore, the introduction effect evaluation of distributed generators in distribution systems can be evaluated quite easily.

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Renewable energy resources are generally unstable and affect the performance of electricity grids when they are fully connected. A distributed energy supply network system is expected to overcome the above problem. Such a system consists of a network system in which electricity and heat can be transferred between dispersion generators and the renewable energy resources and can supply stable energy to an urban district. We have constructed an assessment model to evaluate the energy conservation and CO_2 emissions of a distributed energy supply network system. In this study, we evaluated the introduction of a gas engine cogeneration system (CGS) to a commercial building and the introduction of photovoltaic (PV) systems to residential buildings. The evaluated results indicated that the energy consumption was reduced by approximately 0.1 to 8% when compared to systems that did not have an energy network. The energy-saving rate varied, depending on the conditions such as the scale of buildings and the number of residential buildings.

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Flammability of mixture containing syngas and gasoline in spark ignition engine is discussed as a part of feasibility study of new proposed gasoline engine system, which consists of two engines. In the engine system, the syngas is partial burnt gasoline, and the reactor is one of the spark ignition engines. The syngas is supplied to another engine. The ratio of syngas against mixture was about 34 %. Therefore it was thought that the syngas was burnt in another engine. Lower heating value of the mixture containing syngas, gasoline and air is quite low, comparing with same volume of stoichiometric mixture not containing syngas. The system was proposed to improve thermal efficiency of partial load condition. Experimental data shows the possibility that the system reduces throttle loss. In addition, process of gasoline gasification in spark ignition engine is also effective to improve thermal efficiency.

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In order to improve the performance of 16 V280 diesel engine, the three-dimensional numerical models of the flow field in the nozzle which belongs to the injection system was built, and different detailed flow structures was captured under different pressure conditions. Through the analysis of the flow field, the unsuitable position of the nozzle was located, and the methods which combine CAD/CAM/CFD was applicated to optimize the structure of the nozzle. The analysis results indicate that with the increase of the injection pressure; the flow turbulence intensity increase; the more energy get lost, which caused by turbulence; the coefficient of flow decrease. After the spray nozzle structure was changed into sphere pin valve, the current capacity under the same level of injection pressure was improved greatly.

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Applied software GT-FUEL to build up the physics and the mathematics model of the 16V280ZJ diesel engine' electronics injection system. Ask for the help of solenoid valve to control feeding timing and feeding quantity in order to research on optimization of injection pressure and injection rate curves. In contrast with the experiment of the machine injection system to elaborate the superiority of the electronic control system .It showed that optimizing the fuel injection system by GT-FUEL is doubtlessly practical and theoretically estimable for it could not only cut down the experimental workload but uncover some physical phenomena out of reach for experimental investigations.

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In this paper, we try to carry out a dynamics model of one kind of 16V240 diesel engine using an engine dynamics simulation PC software named GT-CRANK with the method of virtual prototype technology. Contrast the diesel engine journal bearing performance's change rule under the different temperature of the lubrication oil, then provides the evidence for improved design of the locomotive diesel engine.

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A plant dynamic simulator was developed for analyzing operational characteristics of power generation plants. The main feature of the simulator is an automatic code generation functionality through links to CAD systems containing information on piping and instrumentation of plants that have been specified during plant design. The automatic code generation system is expected to provide significant reductions in development time for new plant dynamic simulators. The automatic code generation system was applied to a conventional power plant system with a condenser and a water feed system. The following results were obtained: 1) Component models were identified from the CAD systems by automatic analysis of the data structure of piping and instrumentation diagrams. 2) The identified component models were automatically related to input and output connections according to the given system piping configurations.

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It is necessary to maintain or improve the thermal efficiency and decrease the maintenance cost in thermal power plants. For that, it is necessary to investigate the performance deterioration factors and solve the problem promptly. However, it is difficult to adequately understand the internal state of the plant and to find the performance deterioration factors only by the measurement data. Therefore we developed the method and the program based on heat and mass balance analysis to calculate the immeasurable quantity of state, efficiency of each equipment in a thermal power plant and the influence that these factors give to thermal efficiency. Moreover the performance of the plant can be simulated when the operating condition is changed. By using the method, we came to be able to investigate the performance deterioration factors in power plants.

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GT-Power software is used to simulation model for EQD 180N-30 turbo launch machine. According to condition of the different hydrogen blending ratio, and analyse the impact of excess air ratio and Spark Advanced Angle on engine performance. The simulated results show that on the different hydrogen blending ratio, engine has better comprehensive Performance. Through the comparison of the experiment to the simulation results, the simulation results are consistent with the experiment.

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A supercritical CO_2 gas turbine cycle can be effectively applied not only for the nuclear reactor but also for the fossil fired power plant. Since an inlet temperature of heat source for this cycle is considerably high and the CO_2 pressure is also very high, these become difficult design problems. An introduction of an economizer for the combustion gas leaving a CO_2 heater and a double expansion turbine cycle are effective to solve these problems. A specific design of 300MWe plant is shown. As a result of system design, the cycle thermal efficiency became 43.4 %. For the heat exchangers such as the CO_2 heater, the economizer and the recuperators, PCHE type heat exchanger is effective. The component designs for the CO_2 heater, the economizer, S-CO_2 turbines, compressors and the recuperators are shown.

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Considering the thermal economic analysis methods of the auxiliary thermodynamic system of PWR nuclear power plant and the secondary loops of nuclear power plant's features, a Matrix for calculating the efficiency of the secondary loops auxiliary system of nuclear power plant is derived by the aquivalent enthalpy drop theory, the theory of matrix and the normal thermal-equilibrium method, suitable for quantitative thermal efficiency analysis of secondary-loop of PWR nuclear power plant. The structure of this matrix has a mapping relationship with the secondary-circuit of PWR nuclear power plant auxiliary system, and it can simplify the thermal economic analysis of PWR nuclear power plant auxiliary system, and provides a theoretic principle for analysing the economics of the thermal system of the secondary-loop of PWR nuclear power plant auxiliary system. An example is given to illustrate the validity of the method, and it indicated that the thermal economics diagnostic method is well defined and easy to be used in system design and operation diagnosis.

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In this paper we propose a new plant of a closed cycle oxy-fuel gas turbine power plant combining a nuclear heat generator. A pressurized water reactor (PWR) is designed to supply saturated steam into an oxy-fuel gas turbine power plant for specific power output increase. The saturated steam from the reactor can be under lower pressure and temperature than those of an existing PWR power plant. In this study we estimated plant performance from the heat balance model based on a conceptual design of a hybrid plant and generating costs of the proposed plant calculated from Japanese cost data of an existing PWR plant and an LNG combined cycle gas turbine plant. The generating efficiency of an oxy-fuel gas turbine plant without nuclear steam generator is estimated to be less than 35 [%]. Based on this efficiency of the whole plant performance, the corresponding generating efficiency of nuclear steam generator contributing to the specific power output of the proposed hybrid plant is estimated to be around 45 [%] even if the steam conditions are lower than an existing PWR plant. The generating costs of the hybrid plant are estimated for some different power capacities from 200 to 1000 [MWe] with gas turbine combustor inlet pressure of 5.00 [MPa]. The generating costs are 15-20 [%] lower than those calculated from the weighted heat performance of both an oxy-fuel gas turbine plant without nuclear steam generator and an existing PWR plant.

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Environmental issues around the world have been attracting our attention, and power plants are required to comply with environmental regulations. Turbine generators are also required to increase their output and efficiency to reduce emission of CO_2. To meet these requirements, we have developed a series of indirectly hydrogen cooled turbine generators up to 580 MVA class. Generally speaking, improvement of cooling system and reduction of energy losses are necessary for large turbine generators to increase their output. The latest technologies such as fluid and electromagnetic analyses are applicable to the design of large turbine generators, and we confirmed that they are highly reliable through factory tests of a 510 MVA generator. In this paper, we focus on the state of the art 350 MVA indirectly hydrogen cooled generator developed with 3D fluid and electromagnetic analyses. The efficiency was increased by 0.2% compared to conventional generators.

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The variable gas exchange valve actuation systems have been developed in order to improve the efficiency of the combustion process. The electro-hydraulic valve actuation (EHVA) systems have good power to weight ratio, high maximum force and good controllability. The disadvantages are limited frequency bandwidth and energy recovery. Each component of the EHVA system has certain energy consumption, which is characteristic to the component. In this study the power consumptions of the components are investigated by means of the simulation. The investigated components are a hydraulic pump, a hydraulic accumulator, a control valve, and hydraulic lines connecting the components. The pressure losses caused by the oil flow are most significant in the control valves, 50-60% of the total energy consumption. If the stored kinetic energy of the actuator and moving oil masses could be reused, the energy consumption could be up to 25% better.

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By introducing corona protection technique on parallel ring, generators are designed more compact for 1000MW/27kV capacity. The invention of directly molded process of voltage grading tapes is used to simplify the courses of manufacture. The most suitable anti-corona material is selected through tests and researches among grading tapes and semi-conductive vanishes. Conventional test methods are broken through by directly testing the AC property of these materials. The voltage grading system works in the aging test of mica paper ground wall under 81kV/10h and 54kV/1000h, which guarantees the life of whole insulation system. The reliability of design leads ahead. The intention of which is properly realized by the training of the workers. Finally, the direct molding process of corona protection technique on parallel ring is applied to all 1000MW generators.

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The Japanese government has launched the "Cool Earth-Innovative Energy Technology Program[2]" in 2008 March to promote international cooperation and actively contribute to substantial global greenhouse gas emissions reductions. 21 technologies that can contribute to substantial reductions in CO_2 emissions by efficiency improvement and low carbonization were selected. The Advanced Ultra Super Critical pressure power generation (A-USC), that aims to commercialize 700 deg-C class pulverized coal (PC) power system with 46% power generation efficiency by around 2015 and 48% efficiency by around 2020, is included in the technologies. We have started a large-scale development of the A-USC technology in 2008 August. 700 deg-C class boiler, turbine and valve technologies, which include high temperature material technology, will be developed. Some candidate materials for boilers are being tested. Turbine rotor and casing materials are being developed and tested, as well.

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Modern society relies heavily on the fossil fuels that lead to the carbon dioxide emissions. The development of 700℃ class advanced ultra super critical plant is one of the solutions for the reduction of carbon dioxide emissions. The technology developments of the 700℃ class USC plant are being evaluated in Europe and the United States. In Japan, the 700℃ class USC technology was chosen as one of the national projects last year. This paper describes the development issues and progress of the turbine material and the structures for 700℃ class USC. It especially introduces the progresses in development of two kinds of unique Ni base alloys.

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Supercritical and ultra supercritical thermal power generating units are the major development power generating units. The main steam parameters of thermal power generating units directly affect on the generating efficiency and pollutant emission. In this paper, the state-of-the-art of oversea supercritical and ultra supercritical thermal power generating units was analyzed. Under the condition of the domestic technology and manufacture capacity, and based on the generating efficiency and unit performance meeting of requirement, the thermal parameters' determination method of ultra supercritical thermal power generating units was studied. Main steam pressure is generally less than 27.56 MPa, and the temperature of main steam and reheated steam is about 600℃.

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In this paper, the operating economy of the 1000MW USC (Ultra Super Critical) steam turbine unit is studied by the energy loss and heat consumption deviation analysis. The heat economy calculation model is built by using the conventional heat balance method and the equivalent enthalpy drop method, and the key parameters on off-design condition are determined, which ensure the accuracy of the results of the energy loss and heat consumption deviation analysis. For some special conditions which are not suitable for the equivalent enthalpy drop method, the off-design condition calculation of the steam turbine and its thermal system is adopted.

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Efficiency improvement of thermal power plants is one of the key technologies to protect the global environment. There are many approaches in this regard, which are investigated and developed around the world. Thermal efficiency of fossil power plants has been improved by raising steam temperature as high as 610 Cin a realization of Ultra Super Critical (USC) steam turbine system. In order to enhance the thermal efficiency further, we are developing the Advanced Ultra Super Critical (A-USC) steam turbine system with technical innovations and the reliable design philosophy. A-USC steam turbines will have steam temperature over 700 C, whose thermal efficiency is much higher and carbon dioxide emission is much less than conventional USC plant. There are many aspects and field of technology for the realization of such steam conditions, for instance, material development, cooling design, casing design, and so on. In this paper, we will describe these items well as system design and turbine structure.

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Problem of lacking water resources that affects the development of the coal-fired power generation units in the rich coal areas of the north of China is analyzed. It is proposed that the air-cooled supercritical and ultra-supercritical steam turbines are the key equipment of water-saving coal-fired generation units with the large capacity and the high efficiency. Technical versions and structure characteristics of the air-cooled supercritical and ultra-supercritical steam turbines are presented. Moreover, the effectiveness in saving coal and water of the air-cooled supercritical and ultra-supercritical coal fired generation units is analyzed. It is showed that the application of the air cooled supercritical and ultra-supercritical steam turbines achieves significant economic benefit and society benefit in China.

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A hybrid computational method using fluid dynamics has been proposed and developed for the blade design of steam turbines. It is composed of three main block: the quasi 3-dimensional through-flow calculation block, the fully 3-dimensional flow calculation block, and the mixing plane block. The hybrid computational method was applied to a 4-stage low-pressure steam turbine, where the rotating blade of the second stage was simulated in a fully 3-dimensional shape. The error in the steam mass flow rate across the mixing plane was confirmed to be sufficiently small, less than 0.5%. Primary design parameters such as the degree of reaction, Mach number and wetness mass fraction distributions were confirmed to be in good agreement with parameters for the fully 3-dimensional calculation of single turbine stage. In addition, the calculation time for four turbine stages was reduced by 40% as compared to the fully 3-dimensional calculation for single turbine stage. The developed hybrid method was judged as useful in the blade design of steam turbines.

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Unsteady 3-D flows through two-stage stator-rotor cascade channels in a low-pressure steam turbine model developed by Mitsubishi Heavy Industry (MHI) are numerically investigated and compared with the experiments. The fundamental equations solved in this study are based on the compressible Navier-Stokes equation and the SST turbulence model in general curvilinear coordinates. The high-order high-resolution finite-difference method based on the fourth-order compact MUSCL TVD (Compact MUSCL) scheme and the Roe's approximate Riemann solver are used for the space discretization of convection terms. A parallelized LU-SGS scheme based on the pipelining algorithm is also employed for the parallel-implicit time-integration. Total pressures, static pressures and yaw angles of flow velocity vectors at the outlet of first-stage rotor, second-stage stator, and second-stage rotor obtained from the computation are compared with the corresponding experiments. Finally the reliability of both numerical and experimental approaches is discussed.

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Numerical simulation is performed on the first two stages of IP cylinder of a 600MW steam turbine using CFD and CHT methods. Cooling effects of HP cylinder leakage steam on IP cylinder rotor is investigated and flow behavior of the leakage steam in cooling passages is studied, with configurations of seals, root bottom gaps and diaphragm-to-disc gaps included. Efficient cooling effects are achieved on the rotor and blade root of the first stage, with highest temperature decrease being up to 90K. No obvious cooling effects are found on the second stage rotor blade and rotor disc. Maximum temperature of rotor groove for first and second stage appears at trailing and leading side of its meshing surface with root flat, with value being 796K and 803K separately, which are 41K and 34K lower than the temperature of IP cylinder fresh mean steam.

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The present numerical work is undertaken to focus on the performance of Tip Chordline Sweeping (TCS) and Axial Sweeping (AXS) of low speed axial compressor rotor blades against the baseline unswept rotor (UNS) performance for different tip clearance levels. This paper presents in detail the trends in blade loading and tip leakage flow as modified by the two rotor sweeping schemes. 15 domains were modeled with 5 sweep configurations (0°, 20° TCS, 30° TCS, 20° AXS and 30° AXS) for 3 clearances (0.0%, 0.7% and 2.7% of the blade chord). CFD simulation and flow analysis are done using commercial CFD package ANSYS^[○!R] CFX 11.0. Turbulence was modeled by standard k-w model employing automatic wall functions. Results are validated with the experimental data available in the literature. Through the results, 20° AXS rotor is found to be distinctive among all the rotors with highest pressure rise, higher operating range and less tip clearance loss characteristics. TCS rotors produced improved total pressure rise at the low flow coefficients when the tip gap is increased. Observations near the tip reveal that UNS rotor shows very high sensitivity in the static pressure distribution for the tip clearance flows while AXS rotor found to be stable than the other rotors when the tip clearance is increased. Besides, AXS rotor has high loading capability and less tip clearance effect on blade loading at the near stall mass flow. At non-zero clearances, much of the leakage flow exits the clearance gap with a negative axial velocity component, creating vortex related flow blockage. At both non-zero clearance levels, this blockage is highest for the UNS rotor and lowest for the AXS rotor. UNS rotor leakage vortices penetrated more into the passage before the axial velocity deficit getting sufficiently dissolved. This problem is found to be less for the swept rotors.

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Half ring structure is used for a stator vane of turbo-machinery. In order to exactly analyze the vibration response characteristics of a half ring structure, a whole model should be used, because the cyclic symmetry method cannot be applied for it. In the mechanical design, however, it is unpractical to carry out the vibration response analysis using a whole model. In this paper, an efficient method for predicting the vibration response characteristics of a half ring structure is proposed. The vibration response characteristics of a half ring structure and a full ring structure are compared, using the formulation derived. The vibration response analysis for an actual steam turbine vane with a half ring structure is carried out to verify the validity of the method proposed here. The vibration characteristics of a half ring structure are also verified by the actual loading test.

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In order to study the impact of steam excited force, due to the steam turbine seals clearance, on rotor vibration and stability, a complete structural model of single-disc and single-span continuous rotor system with double bearings and shaft seals is set up. Besides the nonlinear factors such as bending, shearing effect and shaft asymmetry, the combined influence of both steam excited force and bearing oil-film force are taken into consideration. After discretization for the rotor using finite element method, a nonlinear dynamic model of rotor system is built based on the Hamilton principle. The rotor's motion under different spin velocity are studied through numerical analysis, and the results show that the dynamic behavior of rotor has obvious nonlinear characteristics.

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This paper descibes a computational method of random vibration of the turbine blades using the multi-degree of freedom spectrum analysis. This computational method is applied to the cyclic symmetry method to the spectral analysis and enabled a large-scale calculation of the steam turbine blades. In this computational method, it especially focused on the grouped blade structure. The grouped blade structure has the feature from which the response of two or more modes is calculated with one harmonic number. Also, the random vibration examination by a simple blade model was performed. Both modal damping and random excitation PSD (Power Spectrum Density) are the most important factors of the calculation. The experimental results demonstrated that the random vibration response of the turbine blade can be estimated by this calculation method.

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An optimized structure of the integrated shroud for the circularly interlocked turbine blade is highly advantageous to increase system stiffness and decrease dynamic stress. But the working condition of the interlocked structure could affect the blade's natural frequencies greatly. The shroud gap is one of the most important design parameters for the circularly interlocked blades. To ensure a credible frequency and stress for the blade, it is necessary to choose an appropriate shroud gap to make all the adjacent shrouds pin together effectively at the rated turbine speed via the untwist effect. This paper is devoted to study the natural frequency and the coupling situation of the interlocked blades with varying shroud gap width. The commercial FEA software ABAQUS is employed to perform the simulation and the modeling results are compared with the measurement results.

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The fatigue life estimation of structural components is one of the most interested subjects in engineering fatigue research. There exists complex energy phenomenon in the fatigue damaging process. Further studies shows that energy index has many advantages in describing the fatigue behavior of materials, while the development of the energy-based fatigue theory is very limited. In this paper, a new irreversible-energy-based method based on experimental regularity was lead in to consider the influence of the stress level and temperature on the accumulated damage process. At the end of the paper, the method was implemented with the experimental data, damage model and finite element technology on quenched and tempered low-alloyed material 30Cr2MoV. A little example was given to verifying the validity of the method with traditional life assessing method.

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Based on the mode III stress intensity factor, three kinds of crack and their influence on rotor's torsional shear stress are studied in this paper. By deducing and calculating the stress intensity factor K_<IIIA> both for the transverse straight crack model and the transverse semi-elliptical crack model, and for the transverse straight crack model and the slant crack model, relationships between K_<IIIA> and a/R for these models are obtained. Then, W_e (the relative difference concerning torsional shear stress of the transverse straight crack model and the transverse semi-elliptical crack model) and W_<sl> (the relative difference concerning torsional shear stress of the transverse straight crack model and the slant crack model) are defined. In addition, the relationship between a/R and (a/c)_<cr> and the relationship between W_<sl cr> and θ_<cr> are obtained. They are very useful for engineering applications when simplicity is needed.

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