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Although the non-oxygenated triterpenic hydrocarbons (primarily C34H58) produced by the Bot-22 strain of Botryococcus braunii are exceptionally promising candidates for automobile fuel applications, it remains necessary to develop appropriate cracking technologies to convert these oils into a fuel with the required properties. The aim of this research was to develop an on-site process capable of converting the oil extracted from Bot-22 (Bot-oil) to a fuel that satisfies the specifications for diesel fuels, a so-called “drop-in” fuel. One of our primary goals for this on-site conversion was to have it operate as a low-temperature process. In this study, an experimental analysis of Bot-oil catalytic conversion under mild conditions was performed. The results demonstrated that the Bot-oil conversion reaction will proceed at temperatures as low as approximately 200 °C, and that the lowest temperature which resulted in a suitably efficient reaction was found to be 260 °C, generating a yield of 85 %. The physical properties of the converted oil were found to come close to satisfying Japan’s JIS #2 diesel fuel specification. The converted oil’s cetane number (CN), one of the most important quality indexes of diesel fuels, was estimated by measuring its ignition delay in a constant-volume combustion chamber. The estimated CN of the converted oil had a value of 40, which is 5 points below the JIS #2 requirement. It is thought that the Bot-oil can be used to produce a drop-in fuel using a simple on-site conversion process, although further development is required to achieve this aim.

Stator coils transposed by 540deg are widely used as one of the solutions to reduce the circulating current loss in the coil strands of turbine generators. However, the difference of the leakage fluxes in the two coil end parts, which is possibly caused by the coil end length deviation, the winding pitch, and the presence of the connection rings, may induce unbalanced voltage in the stator coil strands, which increase circulating current loss even in the transposition coils. This paper describes the mechanism and the analysis results of the circulating current increase in the coil strands due to the coil end flux difference. Then, some new schemes to reduce the circulating current loss are proposed and discussed.

Experimental and numerical analysis of methanol steam reforming for fuel cell have been carried out. The reforming catalyst was supported by metal honeycomb to decrease the heat capacity. Conversion performances were improved by segmenting the catalyst into several blocks due to the enhancement of mixing of gases and heat transfer at the front edges of the segmenting catalyst. Numerical simulation model for methanol steam reforming catalyst was developed by changing chemical reactions in the model for exhaust catalyst of internal combustion engine and using a smaller mass transfer coefficient for methanol steam reforming. The calculated results for plate type methanol steam reformer which generates hydrogen of 7 kW (LHV) were also in good agreement with the measurements. It was found that the pattern of heat supply to catalyst and the reformer configuration affected the steam reforming performance. It was predicted that the optimized methanol steam reformer for 50 kW size fuel cell vehicle had a sufficient compactness.

A new method for analyzing electromagnetic force in the end-winding portion of large-capacity synchronous generators is provided and evaluated in comparison with 3D FEM electromagnetic analysis. In addition, a method for estimating end-winding vibration during on-load operation is suggested by measured data at factory testing. Moreover, an evaluation method for insulation degradation after operation is proposed for large-capacity cylindrical synchronous machines, where the end-winding portion is the longest and electromagnetic forces on it are the greatest of all rotating machinery. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 163(4): 78–89, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20666

This paper describes the calculation of reactance based on the FEM method from the point of view of changing conditions of electrical frequency as being effective for considering various kinds of transient phenomena. Moreover, the electromagnetic force on the end-winding of the stator is used to evaluate the strength of the stator end-winding support system, especially for large-capacity cylindrical synchronous generators, where the end-winding portion is the longest and the electromagnetic force on that portion is the greatest of all rotating machinery. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 163(4): 67–77, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20649

After the last war, the output of single Steam Turbine Generator produced by the own technology in Japan returned to a prewar level. Electric power companies imported the large-capacity high efficiency Steam Turbine Generator from the foreign manufacturers in order to support the sudden increase of electric power demand. On the other hand, they decided to produce those in our own country to improve industrial technology. The domestic production of large-capacity 125MW Steam Turbine Generator overcome much difficulty and did much contribution for the later domestic technical progress.

A new electromagnetic force analyzing method in end-winding is provided and evaluated by comparing to 3D- FEM electromagnetic analysis. Additionally, estimating method of end-winding vibration on load is suggested by measured data at factory test. Moreover, evaluating method for insulation degradation after operation is offered for large capacity cylindrical synchronous machines, where end-winding portion is the longest and electromagnetic forces on it is the greatest of all rotating machinery.

The authors have examined the equivalent circuit of synchronous generator and proposed that the field mutual leakage reactance in rotor circuit (Canay reactance) and the saturation of main flux is desirable. This paper describes the study on load rejection characteristic with proposed equivalent circuit model , using the electromagnetic transients program (ATP-EMTP), and compared the results with the experimental data.

Reactance calculation based on FEM from changing frequency point of view described here is effective on considering various kinds of transient phenomena. Moreover, electromagnetic force on the end-winding is described here to evaluate its support system, especially for large capacity cylindrical synchronous machines, where end-winding portion is the longest and electro-magnetic forces on it is the greatest of all rotating machinery.

Highly active and highly selective new catalysts for the selective oxidation of CO in excess H 2 were prepared by depositing large amount of FeO x on 1 wt.% Pt/Al 2 O 3 , 1 wt.% Pt/CeO 2 , and 1 wt.% Pt/TiO 2 catalysts (100 times in weight of the Pt ). Optimum activity of the FeO x /Pt/Al 2 O 3 and FeO x /Pt/CeO 2 catalysts was attained at 130–140 °C while that of the FeO x /Pt/TiO 2 catalyst was at 70–100 °C in the space velocity of 15,000 and 36,000 h −1 . CO conversion of the FeO x /Pt/TiO 2 catalyst was ca. 70% at 40 °C in a flow of 15,000 h −1 . Optimum temperature of the FeO x /Pt/Al 2 O 3 , FeO x /Pt/CeO 2 , and FeO x /Pt/TiO 2 catalysts depends on the support oxides, and the feature of the new catalysts is different from that of such metallic catalyst as Pt/Al 2 O 3 , Pt/CeO 2 , and Pt/TiO 2 .

The history of electrical rotating machines such as generators and motors in Japan is around one hundred years. At early stage, all machines were imported from foreign countries, but now domestic industries introduce new concept of machines and are leading these kinds of technology. Reviewing of history and development and foresight seems meaningful for further development.

The catalytic methanol steam reforming reaction was investigated by numerical simulation and experiments. Methanol conversion ratio as well as carbon monoxide (CO), which poisons a typical polymer electrolyte fuel cell, increases in a tablet catalyst when temperature is elevated. There is a trade-off relationship between methanol conversion ratio and CO concentration. It was found that the reforming reaction is controlled by heat transfer at large methanol flow rate, where the trade-off relationship shifts to lower methanol conversion ratio and higher CO concentration. To improve the trade-off relationship, internal corrugated metal heater and external catalytic combustion heater were applied to enhance the heat transfer. Optimal cell density for the internal corrugated metal heater, which was about 9×10 5 cell/m 2 , was closely related with reaction parameters such as velocity, cell density, geometric surface area and hydraulic diameter. The catalytic combustion heater is larger than the internal corrugated metal heater in size. Both high methanol conversion ratio and low CO concentration were accomplished by heat transfer enhancement with the two techniques at large methanol flow rate.

In order to estimate the losses and temperature rise at the end of electrical machines, it is important to clarify electromagnetic behavior in the core end region. In this paper, the method of evaluating the leakage flux of the stator end region of large turbogenerators, combining three-dimensional magnetic field analysis and phasor diagram analysis of the end leakage flux is described. Moreover, the result of applying this method to a 60 Hz-1000 MW turbogenerator is also described.

In our previous study, it has been reported that exhaust smoke can be reduced in an experimental single cylinder diesel engine with the use of air-jet turbulence in the late combustion period. In this study, a device to generate air-jet turbulence in the late combustion period was applied to 6-cylinder DI diesel engine. The effect of parameters such as air-jet direction and timing were investigated. Smoke and particulates were reduced significantly without increasing NOx. Total particulates reduction by the air-jet in Japanese D13 mode is 37% for the constant NOx.

This paper describes the analytical study on generator load rejection characteristic using the advanced equivalent circuit model. The authors have studied the synchronous machine equivalent circuit model and transient phenomena, by simulation with the electromagnetic transients program (ATP-EMTP), and compared the results with the experimental data.

This paper describes the effects of field mutual leakage reactance in rotor circuit (Canay reactance) on analysis of generator transient and dynamic behavior. The authors derived a detailed equivalent circuit model for generator, and analyzed sudden short circuit out-of-phase synchronization load rejection and sudden load application phenomena of the generator by simulations using the electromagnetic transients program (ATP-EMTP). Then, they compared the obtained results with the experimental data to verify the validity of the proposed equivalent circuit. In addition to these analyses, the influence of field mutual leakage reactance on analysis of power system dynamic stability was investigated.

On the air-cooled turbine generators, windage loss is the substantial factor of generator losses. One solution for the windage loss reduction is to minimize the amount of coolant air with the multiple-pitched ventilation ducts in the stator core. However, non-uniform duct distribution leads to the circulating currents in the stator bar strands which increase coil losses and cause significant distribution of strand loss. This paper presents circulating currents due to multiple-pitched ventilation ducts and some schemes to reduce the circulating current loss, such as new transposition systems of coil strand

This paper describes the study of synchronous machine modeling particularly with emphasizing on synchronizing phenomena. The authors proposed a graphical method to investigate the induced spiky voltage, examined the transient phenomena by the electromagnetic transient program (ATP-EMTP) and compared the results with the experimental data

Simple generator systems are preferred for thermal power generation because of their better operability and maintainability, and their lower cost. Hydrogen-cooled generators of up to 600 MVA have been developed to meet these customer requirements. Development of this generator was achieved mainly by optimization of the cooling gas flow distribution and high thermal conducting insulation of the stator winding. A 500 MVA turbine generator applying these key technologies has been designed and manufactured, and has shown satisfactory results in a shop test.

The world's largest class 8,880 MVA and 1,603 MVA short circuit generators have been manufactured, commissioned and are working successfully. The 8,880 MVA generator, the largest capacity in the world, is for TOSHIBA High Power Laboratory, and the 1,603 MVA generator is for the High Power Testing Laboratory of LG Industrial Systems Co., Ltd of Korea. These generators are power sources for testing of circuit breakers, and can be operated at both 50 and 60 Hz. This paper describes the specification, design concept, key technologies and field test results of these short circuit generators.

When water permeates the winding insulation in large-scale direct water-cooled turbine generators, dielectric strength drops steeply due to wet heat deterioration. To ensure operational reliability, it is essential to know whether or not water has permeated the insulation, and if so, to determine accurately the degree of deterioration. We have developed a capacitance measuring robot which enables measurement near the stator core end without removing the rotor, and confirmed good results in the field. The robot travelling along the retaining ring can be accurately positioned, and measured capacitances are stable and reproducible. The robot minimizes the extent of disassembly and reassembly, thus greatly reducing the out-of-operation period. Further, because the insulation condition can be accurately determined through its periodical use, we believe that it will contribute to both preventing accidents and assuring generators with high reliability.

Flux analysis by the three-dimensional finite element method is applied to the end region design of large-capacity turbine-generators. Analysis has been done considering three-dimensional electric currents of end region windings and anisotropies of iron cores provided at the end regions. It becomes possible to quantitatively evaluate the effects of flux shunts which has been impossible to do with two-dimensional analysis, and to control leakage flux of end regions. Significant informations on the influence of the relative lengths of stator and rotor cores on end region flux and the optimum stator core end design of large-capacity turbine-generators with lower short-circuit are described.

Application of a thyristor excitation system with high ceiling voltage to the turbine-generator field has required precise evaluation on field insulation, especially against spiky voltage. This paper reports on the investigation of breakdown through and over the surface of field insulating components for thyristor voltage. Particular emphasis is placed on the method for estimating voltage endurance characteristics for thyristor voltage in hydrogen. We established a simple evaluating method on the rotor slot armor by using the relation of voltage endurance characteristics between ac and thyristor voltages. Estimation tests have proved that hazardous points are (a) the surface flashover of the creepage block for initial-stage characteristics and (b) degradation of the slot armor due to partial discharge for long-term characteristics.

This paper describes the technique of three-dimensional graphic display for the shock wave structures. The shock waves generated at a "U" shaped pin which is moving in the supersonic flow field of a converging-diverging nozzle is visualized by the double pulsed holographic interferometry. The hologram obtained by this method is reconstructed and the shock wave profiles at each of the cross-sections of the real image are thinned by image processing. The numerical data which indicated the thinned shock waves are constructed by computer graphics techniques. As a result, the three-dimensional shock wave structures were clearly visualized by graphic display.

The corrosion resistance of hot dipping aluminized steel wire in regard to the effects of additive elements in aluminum bath was studied in comparison with that of galvanized steel wire. According to the above fundamental studies, exposure tests were performed on the aluminized wire with Mn-Al-alloy, the alloy of the highest corrosion resistance, in comparison with galvanized wire in various districts.The results obtained are summarized as follows:(1) In the aqueous solution of pH less than 11, the corrosion resistance of aluminized wire was higher than that of galvanized wire; while, in the solution of pH more than 11, the resistance of the former was lower than that of the latter.(2) In the aqueous solution of 1% HCl, the addition of Mn gave no bad effects on the corrosion resistance of the aluminized wire: though the addition of Si, Ti, Be, etc. gave bad effects. The resistance of aluminized wire with various Al-alloys was remarkably higher than that of galvanized wire.(3) The results of corrosion resistance in the aqueous solution of 1% NaOH of aluminized wire were much lower than those of galvanized wire, but the addition of Si, Ti, Be, or Mn improved the above results.(4) The results of corrosion resistance in salt spray test of aluminized wire were higher than those of galvanized wire, and the addition of one of the above elements more improved the results.(5) The corrosion of galvanized steel wire in A.C.S.R. was advanced by the contact with aluminum wire: while, the corrosion of aluminized steel wire in A.C.S.R. was less than the case of without contact, but rather prevented by aluminizing.(6) According to the results of salt water immersion test and exposure tests in industrial area, seaside district, and volcanic or hot spring zone, the corrosion resistance of aluminized (with 1.5% of Mn-Al alloy) steel wire was always higher than that of galvanized steel wire.

A flow field survey and aerodynamic force measurements were carried out on a rotating circular cylinder, which was placed perpendicular to the flow near the transition Reynolds number. Remarkable changes in the unsteady wake flow pattern were observed to occur at a particular rotational Reynolds number, which is based on the peripheral speed of the cylinder, with a corresponding abrupt reduction in the steady lift force. The characteristics of the wake vortices also showed substantial difference below and above the same rotational Reynolds number. And it is also made clear that the upper limit of the periodic vortex formation was observed to be governed by a non-dimensional peripheral speed, which is the ratio of the rotational Reynolds number to the ordinary Reynolds number.

In automotive engine combustion, particularly in case of compression ignition in diesel engines, physical properties of the fuel have a direct impact on the spray combustion process. The density, kinematic viscosity, surface tension, and distillation properties of triterpenic hydrocarbons extracted from the BOT-22 strain of Botryococcus braunii (called Bot-oil) were measured, and these properties were compared with those of standard diesel fuel. The density and surface tension of Bot-oil were almost the same as those of the diesel fuel. However, the kinematic viscosity of Bot-oil was 55 to 58 cSt at room temperature, which was 16 times higher than that of the diesel fuel. In addition, the distillation temperature of Bot-oil was approximately 430 °C, which was over 100 °C higher than that of the diesel fuel. To attain the properties required for fuel, a cracking technology for Bot-oil must be established.

Although turbine-generators have recently achieved larger rated output, higher efficiency, and high reliability, it is necessary to continue research and development for further refinement. TOSHIBA has developed a multipurpose full scale generator model simulating a 2000 MVA generator which is predicted as the manufacturable maximum limit for a 3600 r/min machine. This model has the same dimensions as a 2000 MVA generator, but its core length is shortened to one third of the full-length generator. All tests scheduled have been completed successfully. This is a fully water-cooled generator with the maximum diameter rotor for a 3600 r/min machine and has ratings of 30 kV class terminal voltage and 40 kA class armature current. This paper describes the outline of the model and its test results and also shows trends of generator design including the manufacturable limit and its limiting factors.