Toward the improvement of performance of the electric vehicle (EV), the design of the motor shape appropriate to heat removal is important. A typical EV motor is composed of the pair of coaxial cylinders with the fixed outer cylinder (i.e., stator) and rotating inner cylinder (i.e., rotor). The present study experimentally and numerically clarifies the influence of inner shape on thermo-fluid characteristics of the EV motor. The flow behavior in slits between the rotor and stator was measured via PIV. The heat transfer of the gap between the rotor and stator was obtained by the numerical calculation. Furthermore, thermal network was introduced in order to estimate thermo-fluid characteristics among every component of the EV motor. In flow visualization via PIV, vortex flow was observed in the slit on the stator wall. In the numerical calculation, the heat transfer rate of with slit case in the high rotational speed was increased compared with that of without slit case. Hence, it was implied that the heat flux was increased by the presence of vortex of the internal slits. In the temperature estimation, difference between thermal resistances without slit case and with slit case did not affect temperatures of each component.

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Low-grade Thermal Energy Conversion (LTEC) system has a huge energy resource but low energy density. Because the thermal efficiency of cycle is theoretically small, it is necessary to enhance on the system performance of the LTEC system. The Multi-Stage cycle was proposed aiming at optimizing the power output from low-temperature heat sources such as geothermal or waste heat. An evaluation method for the multi-stage power generation system using an unutilized heat source has been proposed in previous studies. In this paper, it is shown on an influence of the heat source temperature and flow rate on the maximum power of Multi-Stage cycle that has independent equipment respectively. As a result, the maximum power output of Multi-Stage cycle increased approximately twice compared with a Single-Stage cycle. The maximum power output ratios of Multi-Stage cycle to Single-Stage cycle are almost same at any heat source flow rate conditions. The thermal efficiency of the cycle for the maximum power of a multistage heat engine was constant in each heat source temperature condition, regardless of the number of stages. The heat source temperature did not impact the increased maximum power efficiency, during an increased number of stages for a multistage heat engine.

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In the Fukushima Daiichi nuclear power plant accident in 2011, the tsunami attacked the power plant and station blackout occurred. As a result, core meltdown was intended at Unit 1, 2 and 3. To remove molten fuels from the Fukushima Daiichi nuclear power plants, it is necessary to know the current status of the reactors. The current status of the reactors may be affected by the thermal and hydraulic behavior of the coolant in the reactors. In the Fukushima Daiichi nuclear power plant accident, seawater was injected into the reactor to cool down the nuclear fuels. The injection of the seawater may change the thermal-hydraulic characteristics in the reactors due to the changes of the physical properties of the coolant. Therefore, the thermal hydraulic behavior of seawater has to be evaluated to consider the current status of Fukushima Daiichi nuclear power plants. However, there is little information about the thermal-hydraulic characteristics of seawater. In order to understand the effects of the seawater on the thermal hydraulic behaviors, a research project was started in Japan Atomic Energy Agency. In this research project, we performed two-different type experiments, one is heat transfer and visualization experiment by using internally heated annulus, the other is a heat transfer experiment by using degraded core simulated test section. The internally heated annulus simulates single fuel rod, simply, and we obtain basic thermal-hydraulics data of seawater in a nuclear reactor. To obtain basic thermal-hydraulics data, we performed the PIV and visualization of steam-water interface by using high speed camera. The thermal-hydraulic experiment by using the degraded core simulated test section was performed in order to investigate the effects of seawater to degraded core cooling. In this paper, the outline of this research project, including objective, outline of experimental apparatus and schedule, is reported. In addition, examples of two experimental results are also shown.

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The heat even at relatively low temperature, such as hot spring, solar energy, waste heat from industry, are regarded as an important heat source of a power generation. When the Organic Rankine Cycle (ORC) is used, the great efforts are paid in order to reduce the irreversible loss at the heat exchangers, in addition to the improvement of the efficiency of expanders and liquid pump. In this study, the improvement of the ORC is investigated theoretically. In order to reduce the restrictions on the heat exchange conditions caused by pinch point that appears at the bubbling point in a normal ORC cycle, the use of a heat pump is proposed. R245fa is supposed as the working fluid of the ORC and also as the working fluid of heat pump. As a heat source hot water at 98℃ is supposed, and as the heat sink 30℃ water is supposed to be supplied. By the small temperature difference between heat source and heat sink, the work of the heat pump is kept at small level. The application of heat pump brings 3 to 28% output increase per unit hot water.

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Usually, Trichloroethane has been used for the de-oiling and cleaning of machine parts. But its production and import have been prohibited since 1995 because of its possibility to destroy the ozone layer. Generally for biological and environmental safety, the de-oiling should be done with the physical method instead of the chemical method using detergent or solvent. As one of the physical method, a cleaning by a supersonic wet steam jet has been proposed. The steam jet with water droplets impinges on the oily surface of machine parts and removes the oil or smudge. In the present study, the low-cost and taper-shaped nozzles were fabricated with an electric discharge machining. The jet behaviors from the taper-shaped nozzles were carefully observed by using air and wet steam. The non-equilibrium model of wet steam was proposed and compared with the experimental results. The spatial distribution of low density regions along the jet axis was considered to contribute the cleaning and de-oiling. However, the condensate generated with the depressurization of steam depressed the injected steam mass flow rate. Furthermore, the steam cleaning was conducted for the plastic coin and the good cleaning effect could be confirmed in spite of the short cleaning duration.

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Europe has a long tradition in utilization of lignite for the Basic Supply of Electric Power. Technology for the combustion of low grade coal has been developed to reach availability for row lignite units above 90% and efficiency rates up to 43%. Large lignite sources exist also in Southeast Asia; however the technology of utilization for power generation is not fully available. Steinmuller Engineering GmbH (SE) is a company located in Germany which has retrofitted more than, 18,000 MW_<thermal> lignite firing systems with modern RSM-Burners. This paper introduces two SE references regarding the improvement of existing lignite fired boilers. The first reference is an example for engineering and supply of Low-NOx firings systems at Maritsa East 3 / Bulgaria, where SE equipped 4 x 227 MW_e units with corresponding systems. The challenges of this project were mainly the very low emissions values and the very short project execution time. Both challenges were managed successfully due to intensive simulations and testing's on the one hand and a flexible project management and engineering team on the other hand. The second reference is an example for engineering work in cooperation with other players. RWE, the second largest utility company in Germany, wanted to modernize two 600 MW_e lignite fired boilers in Niederauβem. Goal of the revamp was the minimization of the possible boiler load (within the existing emission limits) as well as the reduction of the slagging. Interaction between combustion engineering and CFD simulation solves this task and could be successfully implemented.

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Hydropower generation is now attracting attention because of the world's energy problems. With cooperation from the industrial, governmental, and academic sectors, a new type of Francis turbine runner was developed for the Kazunogawa small hydropower generation plant. To validate its performance, a model turbine test facility was built at Waseda University, and a performance test was performed. This experiment confirmed that the maximum hydraulic efficiency was about 88%, and the operational point of maximum efficiency agreed with the design point. Then, using a high-speed video camera, three-hole pitot tube, and computational fluid dynamics (CFD) with cavitation analysis, the loss generation mechanism of the turbine was clarified. In addition, a vibratory cavitation erosion test was carried out to select the material for a prototype runner. It was found that the volume loss of ALBC was lower than that of any other material. At the first stage of prototype turbine design, a design point that could generate the maximum output fora year was calculated using the flow duration curve at the installation location. Then, the loss in the casing and double circular cascade was improved using CFD. Performance and load rejection tests were performed before the prototype turbine operation. It was confirmed that the maximum efficiency was 91%, and the runaway speed was lower than the value predicted by the model turbine test.

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Welding processes and fabrication techniques are being developed for Advanced USC boilers. Advanced 9Cr steels, Nickel base alloys (HR6W, HR35, Alloy 617, Alloy 263 and Alloy 740H) have been selected as candidate materials for the boilers. The GTAW and SMAW welding processes were developed for plates, small-diameter tubes and large-diameter pipes, and welding procedure tests were performed by GTAW; maximum creep rupture tests of these weld joints are expected to take over 100,000 hours. In fabrication techniques, methods for hot bending tests by high-frequency induction heating for large-diameter pipes and cold/hot bending tests for small-diameter tubes have been established. Mock-ups of SH-header and RH-header adequately confirmed the ability of tubes to be fabricated and cold bent, the weldability of pipes, the ability to fabricate at the stub weld joints and the weldability of stub joints. Mock-up tube loops were also produced to confirm the ability of tubes to be cold and hot bent, the weldability at the slide spacer and the weldability of dissimilar weld joints between HR6W and stainless steels. With test-loop fabrication finished, the loop test in the plant has been in progress for two years.

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In the present study, we analytically tackle the development of a prediction model with the experiment as a counterpart. The model separate two stages: (i) CO_2 hydrate is generated from at the interface, and propagated of hydrate under CO_2 hydrate without condition and ; (ii) CO_2 hydrate grew for the case that the hydrate exists. In developing the prediction model, it is necessary to elucidate the diffusion process of CO_2 molecule and H_2O molecule in hydrates. It is, however, difficult to measure experimentally the molecular diffusivity in CO_2 hydrates under high-pressure condition. In this study, we used molecular dynamics simulations to model the diffusion properties of both molecules in hydrates. First, validity of molecule behavior is confirmed that structure was broken at CO_2 hydrate did not exist condition. As a result of calculation varied water vacancies, the vacancy play an important role for molecule behavior and diffusion of each molecule in hydrates.

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Toshiba has enlarged the capacity of indirectly hydrogen-cooled turbine generators (IHCG) with higher efficiency to reduce the CO_2 emission. IHCG has more advantages in maintenance and cost than directly water-cooled turbine generators (DWCG). We have developed high thermal conducting (HTC) insulation technology to improve the cooling performance of the stator windings of IHCGs. Developed HTC insulation had already applied to the actual 670MVA class IHCG, resulting in an increase of generator efficiency. Furthermore, we have completed the design of 820MVA class IHCGs. Currently, we are investigating higher thermal conductive HTC insulation (hereafter called the next HTC insulation) technology. In this paper, experimental results of the next HTC insulation for the actual sized stator bars were reported.

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Carbon Capture and Storage (CCS) is regarded as a countermeasure for global warming, but introduction of conventional CCS system deteriorates thermal efficiency of power station. As a solution, a project has started by NEDO to develop the High-efficiency Oxy-fuel IGCC system, which can keep high efficiency more than 42% even after capturing CO_2. In this system, gasifying agent and combustion air is substituted by oxygen diluted by exhaust gas recirculated from gas turbine combustor. The target of this project was set as to achieve net thermal efficiency more than 42%, which is equivalent to state of the art coal-fired power station. Various approaches were done to confirm the concept of this system and to develop fundamental technologies necessary for achieving this system. This project is a joint development by CRIEPI and Kyushu University. This paper introduces the latest status of this project executed by CRIEPI by referring several related papers.

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It is very important to decrease CO_2 emissions from fossil-fueled power plants while pursuing economically competitive solutions. To achieve these goals, the authors are developing, with other partners, a highly efficient and economical semi-closed power cycle using supercritical carbon dioxide as a working fluid. Major components of this cycle include an air separation unit, turbine and combustor, generator, compressor, pump, and economizer heat exchanger. Fossil fuel, typically natural gas or syngas from coal gasification, is fed into an innovative combustor at high pressure together with pure oxygen from an air separation unit and a stream of hot, high-pressure CO_2 recycled from within the semi-closed system. The two major products from this combustion process are CO_2 and H_2O. The H_2O can be easily removed from the cycle, leaving a high-pressure, high-purity carbon dioxide working fluid. As a result, excess combustion-derived carbon dioxide can be sent into a pipeline without requiring extensive cleanup or further compression, and therefore there is no negative impact on the thermal efficiency of the plant. The net thermal efficiencies of commercial plants with 100% carbon capture are projected to be 59% for natural gas and 51% for coal (LHV), taking all parasitic loads such as the air separation unit, compressor, pump, and all other equipment into consideration. The cycle is being demonstrated through a 50MWt power plant that will validate all of its characteristics. The FEED study for the plant has been completed, the site has been selected, permitting is underway, purchase orders have been issued, and manufacturing of some of the major components has begun. The components of the demonstration plant have all been selected and designed as a scale down of the future commercial plant design, which has a capacity of 500MWt to 600MWt. This paper describes the characteristics of and commercial development status for the cycle, with a particular focus on the development of the turbine and combustor.

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The purpose of this study is to develop the compact auxiliary water heater for home CHP (combined heat and power). The tubular flame is formed in a swirling flow field by injecting the air-fuel mixture tangentially into the cylindrical chamber. In this study, the effect of the swirl intensity on heat transfer characteristics is investigated. In this experiment, the swirl intensity S_w was changed by the thickness of the inlet slit nozzles, as S_w = 3.9-14.3. The heat transfer characteristics on the coiled tube was investigated under the combustion and non-combustion conditions. The combustion rate was 5-15 kW at the air ratio of 1.5. The swirling flow causes the high heat transfer coefficient than that at the non-swirling flow condition at the same flow rate. Averaged heat transfer coefficient on the coiled tube at S_w = 14.3 showed about 1.7 times higher than that at S_w = 3.9. Averaged heat transfer coefficient on the coiled tube heat exchanger agreed with the Dhir's correlation, which was conducted under the swirling flow under the non-combustion condition.

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A large-scale CCS demonstration project is currently being undertaken by the Japanese government in the Tomakomai area, Hokkaido prefecture, Japan. The project is scheduled to run for the period JFY 2012-2020 to demonstrate the viability of CCS system from CO_2 capture through to injection and storage. 100,000 tonnes per year or more of CO_2 derived from an industrial source will be injected from land and stored in two different saline aquifers under the seabed in the offshore area of the Tomakomai Port. At the capture facility, gaseous CO_2 of 99% purity is recovered by an activated amine process. A two-stage absorption system with a low pressure flash tower has been selected to reduce the amine reboiler duty in the capture system expected to be 1.0 GJ/ton-CO_2 or less for the typical CO_2-containing industrial feed gas. The construction works are currently progressing on schedule for planned CO_2 injection startup in 2016.

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In order to reduce CO_2 emission from thermal power plants with keeping high thermal efficiency, a new concept of IGCC system, namely oxy-fuel IGCC, is recently proposed. CO_2 is recycled in this system, hence the effect of CO_2 recycle should be clarified. In this study, the effect of recycled CO_2 injection on coal gasifier performance was investigated by means of three-dimensional RANS-based numerical simulation. In calculation of a coal gasifier, coal char gasification and water-gas shift reaction are important phenomena, therefore, the partially active site sharing coal gasification model and detailed chemistry of water-gas shift reaction model were implemented. The results show that recycled CO_2 injection promotes coal gasification for the lower oxygen concentration condition in which gaseous concentration temperature is relatively high. On the other hand, for higher oxygen and CO_2 concentration condition in which gaseous temperature level is relatively low, it is important that how much the higher gasification reactivity in a gasifier is exploited by optimizing local heat balance. It is essential to locally control exothermic gaseous and endothermic heterogeneous reaction in order to take advantage of recycled CO_2 injection in the O_2/CO_2 blown gasifier system.

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In order to obtain the turbine blade's vibration characteristics under different damping conditions, and to improve the turbine blade design level, a finite element model of turbine blade is developed in this paper. Based on the Mindlin contact model, point-to-point contact condition is simulated, while based on the one-bar microslip model, face-to-face contact condition is simulated. The two models adopted in this paper have been proved to be very accurate in describing corresponding contact phenomenon. The turbine blade response under different contact model, different normal pressure and different damping locations are calculated. It can be obtained that, there is an optimal normal pressure that generates minimum response of turbine blade. In addition, the optimal normal pressure is different when the damper is located in different locations, and there would be a best location that makes turbine blade the minimum response. The turbine blade may have different responses when different models are adopted, this is because there would be differences of stiffness and damping when different models are adopted. The computational method adopted in this paper can be generalized to the analysis of damping turbine blade, and could provide a foundation for the development of damping turbine blade.

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This paper proposes a particle swarm optimization algorithm-based finite-time convergent sliding mode control for the application of solar inverters. Though classic sliding mode control (SMC) is insensitive to parameter variations and disturbances, it has an infinite system-state convergence time. For high-accuracy tracking control, finite-time convergent sliding mode control (FTCSMC) is developed and provides finite system-state convergence time. But, the chatter problem still exists in FTCSMC, and such problem will incur high solar inverter voltage harmonics and slow dynamic response. To obtain high-quality solar inverter output voltage, the particle swarm optimization (PSO) algorithm is applied to optimally tune the control gains of the FTCSMC for eliminating the chatter. By combining a FTCSMC with PSO algorithm, a closed-loop solar inverter yields good performance under various loading. Simulation and experimental results show that the proposed control can achieve low total harmonic distortion (THD) under nonlinear loading conditions and fast dynamic response under transient loading conditions. Because the proposed control is simpler to implement than prior techniques and offers more exact and rapid convergence, this paper will be of interest to designers of related sustainable energy systems.

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The development of small-scale Organic Rankine Cycle systems is currently pursued, especially for automotive applications. The design of such systems is very challenging because the small capacity and constraints on weight and volume imply designs which are far from the design envelope of conventional ORC power plants. Achieving an optimal design by integrating all systems components is very difficult if performed with the conventional approach, which tackles all the design sub-problems in sequence. This work presents, therefore, a new methodology whereby the thermodynamic cycle and the components preliminary design are simultaneously optimized. To this purpose, a modeling code has been developed that couples a routine for the thermodynamic cycle calculation with a 1D tool for the preliminary sizing of plate heat exchangers and a 0D model for the evaluation of the turbine performance. The case study considered to test such a methodology is the design of an ORC unit for waste heat recovery on board of long-haul trucks. The results show that, unlike the sequential approach, the integrated methodology reveals the relations between the design variables and the constraints, notably those concerning the turbine technical feasibility and the exhaust gas pressure drop. Thanks to this information, the designer can identify the trade-offs among the different design objectives and evaluate the sensitivity of the system performance with respect to key design variables, e.g., minimum temperature difference in the exchangers and evaporating pressure. For the specific test case, the optimal solution corresponds to a waste heat recovery system featuring at the design point (Diesel engine power output of 100 kW) a mechanical power close to 3 kW, evaporating pressure of 1.1 MPa, and a 94 krpm turbine with an isentropic efficiency of almost 80%. Although applied to the design of a mini-ORC system, this integrated design procedure is applicable to any conventional or novel ORC turbogenerator.

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The combined flue gas-steam heat regeneration cycle is a newly proposed concept. It combines boiler flue gas and turbine steam into a regeneration cycle so as to maximize the usage of thermal energy. Using low pressure extracted steam heats cold air. High temperature flue gas heats feed water for boiler. Re-ducting energy loss in the heat exchange. The optimal temperature of air at air preheater inlet, optimal temperature of feed water are calculated in this paper. Taking a ultra super-critical 1000MW unit as an example, the coal consumption can be reduced by 6.9g/KW.h.

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This paper briefly introduced the structure of DHN type saturated steam boiler, and taking the DHN-type saturated steam boiler as an example, the modification scheme to meet the needs of the production process steam was presented by improving the boiler steam temperature, neither changing the structure of boiler pressure parts nor increasing the operating pressure, and the main parameters of the before and after modification were tested, it achieved good economic benefit through the practical operation and provided the theoretical basis for the transformation of small steam boiler.

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The ultra supercritical boiler technology with double reheat can significantly increase the efficiency of a Rankine cycle power plant, and reduce fuel consumption for a given output. Recently China is developing 1000MW ultra supercritical boiler with double reheat which is arranged in tower type and the steam parameters are 350bar, 605℃/613℃/613℃. Thermal-hydraulic analysis is the key factors for the design and operation of ultra supercritical boiler with double reheat. According to the boiler structure and furnace-sided heat flux, the water wall of an ultra supercritical tower boiler with double reheat is treated in this paper as a flow network system consisting of series-parallel loops, pressure grids and connecting tubes. Based on the mass, momentum and energy conservations and some supplementary equations, a mathematical model is developed. Pressure drop, mass flux distribution, outlet vapor temperatures and metal temperatures data in the water wall at BMCR (boiler maximum continuous rating), 75% THA (turbine heat acceptance) and 30% THA load are obtained by iteratively solving the mathematical model. The results show that the water wall in the ultra supercritical boiler can operate safely.

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Towards new conceptual magnesium-based fuel (Mg/AP/HTPB) water ramjet, under actual working conditions (about 3 MPa, 3000 K), water dissociation effect will influence combustion process due to dissociation production O_2 participating in reaction as well. Firstly, a one-dimensional numerical simulation of Mg/H_2O premixed gas was conducted to calculate the finite rate and equilibrium temperature. The results reveal that temperature pulsation and further heat release rate pulsation would be aroused under consideration of water dissociation, and this phenomenon is applicable to actual magnesium-based fuel combustion. Especially, thermoacoustic oscillations will occur and grow if heat release pulsation is sufficiently in phase with sound pressure pulsation, sometimes with catastrophic results. Then aiming at such potential destructive thermoacoustic oscillations phenomenon, a one-dimensional numerical calculation model considering a mean flow was established to achieve complex frequency under different working conditions. The results indicate that the oscillation model belong to low-frequency oscillation due to real part of eigenfrequency less than 700 Hz, while the imaginary part profile of complex frequency representing the growth or decay of amplitude, and water/fuel ratio, water inlet position and fuel composition all hold great influence. In particular, reliable water/fuel ratio range was predicted due to certain magnesium-based fuel and structural configuration to inhibit or control thermoacoustic oscillations. All in all, theoretical investigations of thermoacoustic oscillations in such new conceptual magnesium-based water ramjets hold the innovative significance, and the results achieved in present study would provide some valuable guidance for finding much more effective approach to suppress or control thermoacoustic oscillations.

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Complex multiphase flow, heat transfer and reaction process in entrained flow gasifier can't be measured directly. The numerical simulation and process investigation will supply technical support for gasifier design and operation. SG-Vortex gasifier is a new type entrained flow coal gasifier developed by SBWL. Numerical simulation and process investigation of three-stage SG-Vortex gasifier have been carried out in this study. A comprehensive three-dimensional numerical model is developed for simulation of the industrial scale SG-Vortex gasifier. The dry pulverized gasification process is divided into several submodels. The Realizable k-ε model is applied to close the Reynolds-averaged Navier-Stokes equation for gas phase, and the Random-Trajectory model is used to simulate the behavior of particle flow in gasifier. Water evaporation, coal pyrolysis, and homogeneous and heterogeneous char reactions are all considered. The P1 model is adopted to calculate the radiative heat transfer in gasifier. Otherwise, the water shift reaction process in second stage of gasifier is studied. The results indicated that the coal particle enrich on the wall above the burner and bottom of gasifier, the particle is effected by centrifugal force. So steady slagging flow can be formed on the surface of the membrane wall. Furthermore, the eddy effect also led the particle flow to the wall of gasifier and deposited, and the slagging formed on the wall of gasifier molted and flow down from the top of gasifier. Temperature and syngas composition distribution in the gasifier is agreed well with similar industrial gasifier. Water shift reaction exists in second stage of gasifier, and the shift efficiency over than 20%. So the H_2/CO will increase more than 100% compared to general entrained flow pulverized coal gasifier. This advantage led a significant cost saving of investment and operation cost from shift unit.

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Fault diagnosis for Steam Turbine Flow Passage (STFP) is of great importance to maintain the operation of steam turbine in thermal power plants. STFP usually work under time-varying running conditions due to the variable loads, the thermal parameter signals in such an environment are hence highly non-stationary and non-linear. In this paper, a novel fault diagnosis method based on Empirical Mode Decomposition (EMD) - Kernel Principal Component Analysis (KPCA) feature extraction and Support Vector Machine (SVM) is proposed for STFP. Firstly, EMD is applied to extract the fault features of thermal parameter signals. Then, KPCA is applied to further reduce the amount of feature eigenvector and wipe off the redundant features to improve accuracy. Finally, the low-dimensional eigenvectors are inputted into a SVM to recognize faults. Based on practical normal signals, which are collected from a CLN600-24.2/566/566 steam turbine, four types of representative fault signal of STFP are simulated and applied to test this method. The calculation results verified that the proposed method can detect STFP faults quickly and accurately.

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Hot-state numerical simulation was made to study the combustor of a heavy duty gas turbine. The model was devided into three parts: liner cap, full scale liner and transition piece. Three-dimensional flow field and temperature distribution were obtained from the calculation of combustor, which adopted axial swirler on the liner cap and gas jet orifices with different arrangement. The effect of different swirler blade angle on combustion was studied. Results reflect the characteristics of combustion flow field well and has important reference significance to the design of heavy-duty gas turbine combustor.

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The working state of wind turbine blades has profound significance for the safe and efficient operation of wind turbine, which causes scholars extensive research interest. Several kinds of sensors were applied to monitor the state of wind turbine blades, however most of them can be used in the laboratory rather then wind power factory for the reasons such as high price or short lifespan etc. The development of computer vision provides a novel solution for wind turbine blades surface fault diagnosis. This paper use computer vision method to solve the problems of fault detection and classification, which is a theoretical foundation for on-broad diagnostic system of wind turbine blades fault diagnosis. A detail introduction is made of how to identify and classify surface fault of the blades from an image including both blade and background. The arithmetic based on combination of gray gradient and mathematical morphology method is used to extract blades image which are in the picture of complex background, which is a more effective way compared with the results of some traditional image extraction mathematical method. Dual tree complex wavelet was involved to extract image features with 5 other image feature extraction method to determine blade fault types, and the result showed that it can improve the effect of fault diagnosis significantly.

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This paper selects absorption line near 2.25μm, and has temperature correction test range 20〜270℃, this allows more accurate measurement results. It makes relative error from 67.53% to 3.33% at 200℃. Design and install measuring gun, and realize continuous on-line measurement of SCR process ammonia slip of a power unit of Jiaxing Jies Power Plant, the measurement results basically reflect the real-time ammonia slip rate of this power unit. It lays the foundation for future power plant continuous on-line measurement technology for the escaping ammonia of SCR process.

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The radical change in physical properties near the critical point may limit the heat exchange rate of printed circuit heat exchangers (PCHE) due to the presence of a pinch point inside the regenerative heat exchanger. Experimental and numerical investigations on forced convection heat transfer of carbon dioxide at supercritical pressures within a semi-circular PCHE have been performed in the present study. Primary operational parameters included inlet pressure ranged from 7.5MPa to 8.5MPa, mass fluxes ranged from 108 kg/m^2s to 760 kg/m^2s and the average heat fluxes was from 20kW/m^2 to 90kW/m^2. Good agreement was found between the experiments and numerical simulations by SST k-w model with the near-wall region being completely and accurately resolved. A physically improved semi-empirical correlation for the forced convection heat transfer of supercritical CO_2 within the PCHE was developed by implementing probability density function (PDF)-based property revised technique for more reasonably interpreting the influence of instantaneous turbulent temperature and fluctuating properties. The predictions of the PDF-based new developed correlation are significantly improved so that more than 96% data in the heating mode and more than 92% data in the cooling mode with various heat fluxes are captured and collapsed to an ideal straight line within an accuracy of 25%.

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Microwave irradiation was employed to upgrade the physicochemical properties of Philippine lignite with high moisture and oxygen content to prepare high-quality coal water slurry (CWS) fuel for gasification. Characteristics of the CWS char-CO_2 gasification were investigated on a pressurized thermo-balance. It was found that microwave irradiation can effectively decrease the CWS apparent viscosity. In addition, the gasification temperature and activation energy of CWS char prepared from the microwave upgraded lignite decreased, indicating the gasification reactivity increased. The CWS char prepared from the microwave upgraded lignite was more responsive to the gasification pressure. The gasification activation energy of CWS char prepared from raw lignite and microwave upgraded lignite decreased from 222.3 KJ/mol and 220.7 KJ/mol to 220.5 KJ/mol and 184.8 KJ/mol, respectively. The reason was that metal ions such as Na^+, Ca^<2+> and Mg^<2+> concentrated on the lignite particle surfaces by microwave irradiation catalyzed CWS char-CO_2 gasification.

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Structure strength design methods for very high pressure (VHP) rotors of 700℃ USC Steam Turbines are introduced. Steam thermal parameters of blade stages of VHP welded rotors are analyzed. The transient finite element analysis is implemented for start and shutdown process, including cold start, warm start, hot start, very hot start, sliding-pressure shutdown and normal shutdown, to obtain the temperature and stress distribution of the VHP welded rotor. The strength design criteria and strength analysis results are given for 700℃ USC steam turbine VHP welded rotor. The results show that the structure strength design of 700℃ USC Steam Turbine VHP welded rotor is safe.

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The calculation and assessment method for the crack propagation life under low cycle fatigue and high cycle fatigue of nuclear steam turbine rotors is presented. The loads and fatigue cycle stress amplitude, the threshold and material constants of the fatigue crack growth as well as the crack propagation life calculation methods for low cycle fatigue and high cycle fatigue of nuclear steam turbine rotors are introduced. The calculation and assessment method for the crack propagation calendar life under low cycle fatigue and high cycle fatigue of nuclear steam turbine rotors are given together with an application example for calculation and improvement of the fatigue crack propagation calendar life of a low pressure rotor for 1000MW nuclear steam turbines. The analysis results indicate that effect of the high cycle fatigue on the fatigue crack propagation calendar life of nuclear steam turbine rotors can not be ignored. It is necessary to evaluate the crack propagation life under LCF and HCF interactions, both for new designed nuclear steam turbine rotors and defect nuclear steam turbine rotors in service.

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Using wood chip gasified gas WCG as the design fuel, under the operation restriction of the fuel cell, reformer and gas turbine, the performance of an intermediate temperature-solid oxide fuel cell(IT-SOFC) and a gas turbine(GT) hybrid system was analyzed. Using non-design fuels (such as cotton wood gas CWG, grape seed gas GSG and corn stalk gas CSG), the system operation performance in design and off-design conditions were deeply researched, with the IT-SOFC of 1026K being constant. Results show that, using the design fuel WCG, the output power of hybrid system is 177.72kW, the electrical efficiency is 58.74%, the working temperature of IT-SOFC and GT both satisfy the design requirements, the compressor surge margin is 21.07% and the S/C boundary value is 1.98, the hybrid system has good operation performance. Under the design condition, using non-design fuel GSG, the system output power and efficiency both decrease, the S/C boundary value is higher than 2, the reformer is prone to carbon deposition phenomenon. Using CSG and CWG as fuel, the system output power increases and the efficiency decreases. Under the off-design condition, using the design fuel WCG, the efficiency of fuel cell and hybrid system are higher than that of the non-design fuel. Using GSG as fuel, the S/C boundary value is higher than that of the other fuel, the issue of carbon deposition should be aware. When using the four types of fuel, the system efficiencies are higher than 60% at low load operation, contrarily, the system performances become weak at high load operation. Using the CSG and CWG, the system can have a higher load capacity, however, the carbon deposition is easy to occur. Hence, the types of fuel should be selected appropriately based on the load demand, hybrid system economy and security.

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A multi-spectral imaging system is proposed to reconstruct the soot temperature and volume fraction fields of a laboratory-scale ethylene flame. The Charge-coupled device (CCD) cameras with Liquid Crystal Tunable Filters (LCTF) were applied to capture the multispectral flame images for obtaining monochromatic radiative intensities. The LCTFs provide images of the flame at multiple wavelengths and generate high-resolution spectra at every pixel. A least square QR decomposition (LSQR) method is applied to solve the large ill-posed equations and obtain the multi-wavelength local emission distributions from which temperature and volume fraction profiles can be extracted. Before conducting the experimental measurement, the calibration method of the multi-spectral imaging system is introduced, and the calibration results with 6 different wavelengths are demonstrated. The measured region of the flame is divided into 7×7×3 volume elements, and specifically it is dispersed to 3 layers in the vertical direction. Considering the measured distribution profiles, the experimental reconstruction results are determined to be reasonable.

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Low NOx combustion technology is a clean economic and extremely effective method to reduce NOx emission of coal-fired boiler. It is critical to study low NOx combustion for coal-fired boiler denitration transformation. In low NOx transformation, NOx emission of tangential firing pulverized coal boiler depends on the distance between SOFA wind and upper primary air, the tangential circle size and the amount of SOFA wind. Besides, the arrangement of third wind scale is a long-standing and actual difficult problem, especially to meager coal. In this paper, experimental and numerical methods are conducted to study NOx emission of the transformed 130t/h coal boiler. The numerical simulation shows that the optimal distance between SOFA wind and upper primary air depends on the volatiles and calorific value of coal. The temperature in outlet of furnace is more uniform when the arrangement of SOFA wind takes anti-clockwise. What's more, when the amount of SOFA wind accounts for about 15%〜20% of the amount of secondary air, the NOx emission was significantly reduced without reducing the boiler efficiency. According to the simulation results and practical condition, the 130t/h boiler was retrofitted. Experimental results showed that the NOx emission reduced from 310ppm to 168ppm, with 2.5%〜3.0% oxygen component in flue gas and lower SOFA wind opened.

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Non-premixed flames are widely utilized as pilot flames in lean premixed combustors, which are prone to combustion instabilities. The dynamics of bluff-body stabilized non-premixed flames undergoing sinusoidal modulations in the air flow were investigated by experiments. The flow field, the reaction zone, the pressure oscillation and heat release rate were recorded by the dynamic data measurement system. The dynamics of the flame structure and the flame transfer function were measured in detail at different amplitudes of fluctuation. Analysis of the experimental results shows that the periodical movements of the vortex shedding from the bluff-body play crucial roles on the dynamics of the flames' structure and the heat release rate. There are three typical regions behind the bluff-body, such as the continuous recirculation zone, the vortex-breaking-up region and the bluff-body wake. At large amplitude of velocity fluctuations, the continuous recirculation zone disappears, resulting in the variation of the flame transfer function. When the modulation is intense enough, extinctions appear near the outlet of burner and the flame could blow out. These results help to understand the response of the non-premixed flame to fluctuations of air flow and develop combustion instability control techniques.

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The laser propulsion process of laser supported detonation wave with gas-liquid two phase propellant has been analyzed. The ideal power cycle model of gas-liquid two phase propellant laser propulsion has been established to analyze the energy conversion efficiency using thermal dynamic method. It's founded that the compression ratio and the pressure ratio are the main factors to improve the efficiency of energy conversion and the conversion efficiency can be enhanced through improving the two factors. The compression ratio is related to the inlet Mach number and the pressure ratio is associated with the power density of the laser and the characteristic of the propellant. The efficiency can be improved through increasing the speed of the craft, improving the power density of laser and perfecting propellant. Through mixed with water, the threshold of air breakdown will decrease, the absorbing efficiency will increase and the pressure ratio will increase, thus the efficiency of energy conversion will be enhanced. The study of gas-liquid two phase propellant is of great significance to the later study of laser propulsion.

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This paper introduces the 660MW ultra-supercritical double-reheat steam turbine developed independently by Dongfang Turbine CO.LTD (short for DTC). By improving the steam parameters, optimization of thermal system, using double reheat cycle, application of new high temperature materials, structure upgrading, such turbine parameters are successfully upgraded to 31MPa/600℃/620℃/620℃, power plant generation efficiency reached 46.6%. The unit with the world's highest parameters will be the first double reheat unit in China, provides a feasible path for the plan of energy saving and emission reduction, provides experience for the commercial operation of 700℃ level turbine in the future.

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The LP casing of DFSTW's Ultra-supercritical 1000MW steam turbine is such a structure: 1200mm end rotor blades, bearing seat is cantilever supported on end plate of casing, inner casing is supported on casing by cat's claw. It is very large (long,wide,high=8370×9360×7124mm). So it is very difficult to avoid resonating and impact-rubbing between movable and stationary parts of steam turbine. Based on FEA theory, a three dimensional finite element model of LP casing to analyze the deformation, stiffness, frequency and response has been developed. By using this method, Dong Fang Steam Turbine Works have designed a lot of LP casing, such as steam turbine exported to Middle DFSTW Market is 60Hz model, Ultra-supercritical 1000MW (1200mm end rotor blades) or 660MW generators of LIUHENG, JIAOZUO Power plant etc. in the operation, the bearing Vibration is small, and the stiffness and vibration performance of LP casing have reached the international leading level. Result of FEA calculate is conform with the fact. It shows the numerical analysis can provide usable data for LP casing designing and improving.

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The technical characteristics of the new DTC (Dongfang turbine Co.,Ltd) high efficiency 1000MW ultra-supercritical steam turbine with 1200mm end rotor blade are described in this paper. The detailed optimizing technology of the thermal system, flow passage, structure design and operation mode is illustrated and the corresponding application conditions of these technology are presented as well. The technical index and research and development process of the new DTC high efficiency 1000MW ultra-supercritical steam turbine are also introduced. The heat rate prediction of the unit will reduce 6% by 2022 in order to make the coal-fired unit cleaner and more efficient and then make great contribution to the energy conservation and emissions reduction of the world.

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Under the condition of settled stator blade vortex design, the blade chord variation along spanwise direction can significantly change the endwall losses, and possibly the profile loss in the mid-height section. One way to reduce these losses is by decreasing the relative pitch-chord ratio at the root and tip height region, and increasing it or keeping it the same from the original one at the mid-height region. This paper presents a CFD study where two different stator blade chord spanwise variation methods are applied to the stages of an IP steam turbine. The original one is of the traditional method where the stator blade chord remains constantly or increases linearly along blade height. While the new one has the characteristics as follows: the stagger angle and scale of the 2D profile geometry are changed compared with the original one; the variation of blade chord throughout the height of the blade is parabolic, with large chord in the endwall region, and small chord in the mid-height region; the 2D profile stagger angle on different section heights is changed from the original one to maintain the same blade vortex design; the blade number is slightly changed to satisfy the pitch-chord ratio requirements while keeping the section moduli and moments of inertia almost the same. The CFD calculation results show that, with the new design strategy, the stator endwall loss decreased significantly, and the profile loss in the mid-height section reduced slightly as well, compared with the original one.

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New technologies are applied to improve the aerodynamic performance of impulse high pressure turbine stages based on the conventional impulse stage designs. The new three-dimensional stator blade profile, labyrinth brush seal design and optimized reaction degree distribution are used to redesign the conventional impulse three turbine stages for the high pressure cylinder. The aerodynamic characteristics of the redesigned impulse high pressure turbine stages are experimental measured and numerical simulated at different operational speeds. The aerodynamic parameters of the second stage of the impulse three stages for the high pressure turbines are obtained. The obtained results show that the aerodynamic efficiency of the redesigned impulse turbine stages improves compared to the conventional design. The detailed flow fields and corresponding flow mechanisms of the redesigned impulse stages and conventional design for the high pressure cylinder are also analyzed and discussed.

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Vane failure due to resonance vibration should be avoided in an axis-flow compressor design. So the vibration characteristic of the vane row should be analyzed. The interaction of adjacent blades and vanes causes unsteady flow. Once the margin between the vane natural frequency and the aerodynamic force frequency is insufficient, it will lead excessive vibration stress on the vane. As the vane is assembled as clearance fit, its contact boundary is nonlinear. This paper introduces the equivalent stiffness matrix into the finite element model to calculate a series of equivalent linear vibration system characteristic. For each linear vibration system, the natural frequency of the fundamental modal shape is analyzed. Then the curve of natural frequency to the equivalent contact stiffness can be drawn. A vane modal test fixture is designed to complete the modal identification. Combining the series of modal simulation and test, the natural frequency dispersion of the vane nonlinear vibration system can be predicted. Strain gauge is used to test the vane dynamic stress during the compressor mapping test. The vibration characteristic in the operating condition is compared with the predicted model. The equivalent contact stiffness of the vane in the operating condition can be verified. The results show that the predicting model can be used to analyze the nonlinear vibration characteristic of the vane.

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Four ash samples were taken from the HRSG of a ferrosilicon furnace in western China, which suffered serious slagging and fouling. X-ray fluorescence (XRF), X-ray powder diffraction (XRD) and scanning electron microscope (SEM) were utilized to analyze the ash samples. The results show that low melting point salt and composite salts are absorbed to the superheater tube walls in aerosol form and solidify to form the initial slag layer. With the continuous deposition of the low melting point compounds, more and more ash particles in the flue gas are absorbed to the slag surface to form thicker slag. Low melting point composite salts are absorbed to the evaporator tube walls in aerosol form. With the deposition of low melting point composite salts, more and more ash particles are absorbed to form the fouling. Since there is less space between pin-finned tubes, the larger iron-rich slag particles are easy to deposit on tube walls and fin surfaces, which are advantageous to the fouling process. There are large quantities of superfine ash particles in the flue gas that are easy to be absorbed by other particles or tube walls, which facilitate the slagging and fouling processes.

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The steam-flow-excited vibration and bearing oil whirl are two main faults affecting the safe operation of large steam turbines. According to the non-linear vibration theory and fluid dynamics, the model of steam exciting force in the condition of partial steam admission in governing stage, as well as the steam turbine nonlinear dynamic model with the steam exciting force and the bearing oil-film force, are deduced in this paper. The numerical calculation method is employed to analyze the vibration response of nonlinear rotor system. The bifurcation diagrams of rotor system are obtained under the action of the steam exciting force and the oil-film force separately, as well as in coupling condition. The coupling performance between the steam exciting force and the oil-film force are discussed, and the coupling influence of the steam exciting force and the oil-film force upon the stability of rotor system are analyzed. The results can provide theoretical basis for the performance study of steam-flow-excited in large steam turbine.

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The whole power plant and the process of power generation are so complicated that comprise so many apparatus and systems. Any small part would make the power plant in fault. In order to find and study the fault reasons easily, the whole power plant could been divided into several subsystems in several levels. Study on the fault records of 600MW units, manufactured by Shanghai Electric Power Generation Equipment Co., Ltd. (SECPG), which are running in China. All the records are from China Electric Power Reliability Management Center. With the help of fault matrix, a fault tree covering all fault records on all units has been established. And the fault tree has 5 levels: the whole power plant, turbine and generator, all faulty components, the certain power plants and fault causes. Turbine has been divided into 9 parts, generator has been divided into 4 parts and there are 10 kinds of fault reasons. So it is clear that the connections among all the parts, faults, causes and elements in the final fault tree. The final fault tree and the matrix of faults are digitized, integrated and visualized to represent the faults. The digitized representation is the most imaginable and integrated.

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Coal-fired and gas turbine combined cycle units are two main products of Shanghai Electric Power Generation Equipment Co., Ltd. (SECPG). The carbon emission from these units can be calculated by matrix. Making a list of the carbon emission amount, then the total amount of carbon emission during the past 60 years can be calculated. 320GW of power units have been manufactured by SECPG, so the amount of carbon emission has been mounting as more and more products. According to the data on good authority, our products produced 1.45 trillion-KWH of electricity every year, but 12 billion tons of CO_2 at the same time. After years of effort, as main steam parameters of most high-power power units are higher and higher, the CO_2 emission has been eliminated to 810g/kW・h-900g/kW・h and CO_2 emission from one certain unit a year can drop to 4.63t-4.68t. Although the number of coal-fired units is decreasing, so many coal-fired units are still in China and will be main energy source in the future decades. If CO_2 emission has to be further cut, new energy should be widely used. But new energy can't support the energy consumption of China, so gas energy will be an important part of our energy structure with the coal energy decreasing. All in all it is desirable to develop new and clean energy instead of coal and to eliminate carbon emission effectively.

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As the development of laser technology, acoustic technology and weak signal detection technology, a new concept is put forward to solve the problem of measuring the concentration and distribution of water droplets in wet steam. The study presents the geometry of laser transfers in evaporating semitransparent water droplet in wet steam, analyzing the selective absorption of laser radiation and its influence on the evaporation processes. It's found that the evaporation of water droplets involve in advection, conduction, convection and mass transfer. In the series of physical process above, there are conversions of various energy, light energy, thermal energy and acoustic energy. The emergence of acoustic signal and mechanism of photoacoustic effect in water evaporation process are studied. The relation between droplet lifetime and evaporation rate is investigated. The distribution of temperature and pressure internal water droplet and its influence on evaporation process is indicated. The influence of laser intensity and wavelength and droplet initial state on evaporation process is investigated. In order to investigate the water droplet evaporation theoretically and numerically, it's necessary to simplify the single water droplet evaporation process by reasonable assumptions. The analysis of physical process of liquid saturated droplet evaporation in wet steam provides a certain theoretical basis for further quantitative study in the mechanism of droplet evaporation.

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The evaporation of water droplet is relevant to numerous technologically important applications, such as fire suppression, industrial cooling and so on. For the saturated water droplets in wet steam, the numerical analysis of evaporation process caused by laser radiation is studied. The water droplet is assumed to be spherical and semitransparent to radiation. Based on the traditional model of water droplet evaporation, a simplified physical model is developed and mathematical model equations are set up, which include radiative transfer equations, energy equations and mass transfer equations. Considering the effect of thermophysical parameters varied with temperature on evaporation process, the change law of some parameters is obtained, which include evaporating rate, droplet mass and droplet diameter. The influence law of various initial diameter and laser intensity to evaporation process is explored under this consideration, too. The numerical analysis of single water droplet evaporation plays an important role for further study of mechanism study of wetness measurement by laser-induced vaporization enhanced photoacoustics method.

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The solution of providing industrial extraction steam by F-class combined cycle power plant was discussed, which mainly aimed at providing adjustable extraction from steam turbine with intermediate pressure between 1.0MPa(a) to 2.5MPa(a). By analyzing the traditional extraction solution and the HP exhaust extraction solution, the effect on the performance of steam turbine under design condensing condition was found. The economic benefits on extraction condition by using these two solutions were also compared in this paper, and the recommendation for project was given.

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Finite element analysis considering startup-running-shutdown process was carried out to determine the local mechanical behavior and damage mechanism for one large capacity and high parameter steam turbine rotor. Research indicates that different temperature gradient, peak stress and stress triaxiality exist in different positions of the rotor, resulting in complicate damage mechanism for local area of rotor. For steady operation, high stresses which are induced by thermal-mechanical loads, present in the inlet area. The center of rotor and local complex structure should be paid attention for its high positive stress triaxiality. For transient operation, the heat was introduced or took away from high temperature steam in the inlet zone and axial seal zone, leading special temperature field in the rotor. The stress magnitude strongly depends on temperature gradients in transient operation. In startup process, compressive stresses mainly present in the out surface of rotor, and tensile stresses mainly exist in the center of the rotor. The opposite stress distribution is revealed in the shutdown process. The alternative stress and stress triaxiality in local area were observed in the startup-shutdown process. Additionally, it was found that the rotor was elastic in steady and transient operation. But if extreme conditions (long term creep, fatigue, thermal shock, extreme cold et al.) are subjected, different damage may be occurred. For steady running, the high positive stress triaxialities in the center and local concentrated zone promote long term creep damage. For startup-shutdown process, alternative stresses and stress triaxialities promote energy dissipation of local zone, further cause high fatigue life consumption. In order to keep the rotor operate safely, the stresses at critical points in the rotor should be limited, and the design as well as assessment based on the local mechanical behavior and damage mechanism has to be considered.

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