Hitachi, Ltd.

Petroleum Energy Center

Other

Toshiba Corporation

Hitachi Engineering Co., Ltd.

Hitachi-ge Nuclear Energy, Ltd.

Koji Nishida

Osamu Yokomizo

Junjiro Nakajima

Motoo Aoyama

Junichi Yamashita

Yasunori Bessho

Junichi Koyama

Masao Chaki

Akihito Orii

Shin-ichi Kashiwai

Hirokazu Takahashi

Akinori Hayashi

Masahisa Inagaki

Satoshi Kanno

Yuichiro Yoshimoto

Osami Yokota

Toru Kanazawa

Shozo Nakamura

Takanori Shibata

Shigeo Hatamiya

Susumu Nakano

Yasuhiro Masuhara

Nobuyuki Hokari

Hajime Umehara

Tatsuo Hayashi

Yasuhiro Aizawa

Shinichi Inage

Hideki Kurosaki

Shinsuke Kokubo

Koji Namba

Tetsuo Sasada

Masahiko Yamagishi

Kumiaki Moriya

Katsumasa Haikawa

Kotaro Inoue

Toshifumi Sasao

Kunitoshi Kurihara

Akinobu Nakajima

Yukihisa Fukasawa

Toshitsugu Nakao

Tsunemasa Nishijima

Akio Tomiyama

Yoko Ishibashi

Shigeto Murata

Tadashi Mizuno

Shin-ichi Inage

Kenichi Takeuchi

A boiling water nuclear power plant supplies steam from a reactor to high-pressure and low-pressure turbines. Feed water generated by condensing steam in a condenser is heated by low-pressure and high-pressure feed water heaters and supplied to the reactor. The steam discharged from the low-pressure turbine is compressed by a steam compressor and supplied to one of the low-pressure feed water heaters to heat feed water. The steam extracted from the low-pressure turbine is supplied to the low-pressure feed water heater. When power required for the steam compressor is Q, heat energy supplied from the steam compressor is Q, a coefficient of performance of the steam compressor is COP (=Q/Q), and a thermal efficiency of the boiling water nuclear power plant is &#x3b7;, the steam compression apparatus is connected to a position in a main steam system and to the feed water heater so as to satisfy COP&#x2212;1/&#x3b7;&#x3e;0.

Power plant

An electric power plant supplies steam generated to a high-pressure turbine and a low-pressure turbine. The steam discharged from the low-pressure turbine is condensed with a condenser. Water generated with the condenser is heated with a low-pressure feed water heater and a high-pressure feed water heater. The steam extracted from the high-pressure turbine is supplied to the high-pressure feed water heater. The steam extracted from the low-pressure turbine is compressed with a steam compressor, and the steam whose temperature has been increased is then supplied to the high-pressure feed water heater. The feed water is heated in the high-pressure feed water heater by the steam extracted from the high-pressure turbine and the steam compressed with the steam compressor. Because the feed water is heated by the extracted steam and the compressed steam in the high-pressure feed water heater, the amount of power consumed by the steam compressor can be reduced.

Electric power plant, and method for running electric power plant

The present invention provides a reformed-fuel-burning gas turbine system that constantly generates good-quality reformed fuel even when heavy fuel has a different composition. The reformed-fuel-burning gas turbine system according to the present invention comprises a heavy oil heater; a water heater; a reformer vessel for mixing high-temperature, high-pressure water with high-temperature, high-pressure heavy oil to cause a hydrothermal reaction and producing reformed fuel from heavy oil; and a gas turbine which operates on the reformed fuel. The reformed-fuel-burning gas turbine system according to the present invention further comprises a detector for detecting the static dielectric constants or solubility of high-temperature, high-pressure heavy oil heated by the heavy oil heater and high-temperature, high-pressure water heated by the water heater; a first temperature regulating valve for adjusting the thermal dose of the heavy oil heater; a second temperature regulating valve for adjusting the thermal dose of the water heater; and a control device for adjusting the first temperature regulating valve and the second temperature regulating valve in accordance with the static dielectric constants or solubility of the heavy oil and water, which are detected by the detector, in order to control the static dielectric constants or solubility of the high-temperature, high-pressure heavy oil and high-temperature, high-pressure water, which are to be supplied to the reformer vessel.

Reformed-fuel-burning gas turbine system and method of operating the same

A heavy oil reforming system includes a reforming preheater raising the temperature of a mixed fluid comprising a high pressure heavy oil and high pressure steam up to a temperature for reforming reaction. The mixed fluid having been heated up to the temperature for reforming reaction is introduced into a reformer kept at the temperature for reforming reaction and thereby the heavy oil is reformed. This reforming system allows the attainment of a residence time of 1 to 10 min necessary for reforming in a uniform or nearly uniform temperature field, thereby implementing the manufacturing of reformed fuels from a large volume of heavy oil.

System for reforming heavy oil, method therefor, and combined cycle power system

In a method for producing gas turbine fuel through the step of modifying heavy fuel oil with the use of an asphaltene-insoluble solvent, the utilization factor of the heavy fuel oil usable as gas turbine fuel is increased by making asphaltene selectively removable. A solvent having a specific inductive capacity in the range of 1.4 to 2.0 is used as the asphaltene-insoluble solvent. In particular, water controlled in temperature and pressure so as to have a specific inductive capacity in the above range is used as the asphaltene-insoluble solvent. By using such a solvent, an asphaltene component contained in the heavy fuel oil can be selectively removed and power generation can be performed while utilizing 95% or more of the heavy fuel oil.

Method for producing gas turbine fuel, and method and system for generating electric power by gas turbine

Fuel assembly

A fuel assembly includes a plurality of fuel rods placed in a square lattice array of 9-rows/9-columns and at least one water rod. In this fuel assembly, the fuel rod pitch of the plurality of fuel rods is in a range of 14.15 mm to 14.65 mm, and means for offsetting and holding a fuel bundle composed of the fuel rods and the water rod is provided in such a manner that the center in a cross section of the fuel bundle is offset from the center in a cross section of the lower tie plate toward the channel fastener side. With this configuration, it is possible to provide a fuel assembly for a D-lattice core, which is capable of achieving the fuel economy comparable to that of a C-lattice core without reducing the thermal margin, and of using the existing fuel spacers.

Fuel assembly and reactor core and fuel spacer and channel box

In each of a number of fuel assemblies loaded in a core of a boiling water reactor, a fuel holding portion of a lower tie plate holds lower end portions a plurality of fuel rods and at least one water rod. The water rod includes a rising pipe opened to a space in the lower tie plate below the fuel holding portion and introducing upward a coolant introduced to the rising pipe, and a falling pipe communicated with the rising pipe and introducing downward the coolant introduced through the rising pipe. The falling pipe has a coolant outlet opened to a second coolant passage defined between the fuel rods above the fuel holding portion. The rising passage is filled with the coolant during a period of rated power operation of the reactor, and a surface of the coolant is formed in the rising pipe during a period of non-rated power operation in which a flow rate of the coolant supplied to the fuel assemblies is lower than that during the period of rated power operation. As a result, influences of a transient event during the rated power operation can be suppressed, and the nuclear thermal-hydraulic stability of the core during the non-rated power operation can be improved.

Boiling water reactor core, boiling water reactor, and method of operating boiling water reactor

Each of short-length fuel rods is arranged at a position other than in 3&times;3 corner regions to in such a manner as not to be simultaneously adjacent to a water rod and others of the short-sized fuel rods. Gd fuel rods are arranged at positions excluding the outer periphery, and the number of those of the Gd fuel rods adjacent to the short-length fuel rods is one-half or less the total number of the Gd fuel rods. At a transverse cross-section of a region upward from upper ends of the short-sized fuel rods , the amount of burnable poison contained in a polygonal region whose vertexes are located at centers of those of the first fuel rods arranged at the outermost layer is smaller than the amount of burnable poison outside the region . With this configuration, a critical power can be improved in consideration of both a distribution of the flow of coolant and a distribution of a thermal power in the fuel assembly.

Boiling water reactor core, boiling water reactor, and method of

Each of short-length fuel rods 3 is arranged at a position other than in 3.times.3 corner regions 6 to 9 in such a manner as not to be simultaneously adjacent to a water rod 5 and others of the short-sized fuel rods. Gd fuel rods 4 are arranged at positions excluding the outer periphery, and the number of those of the Gd fuel rods 4 adjacent to the short-length fuel rods 3 is one-half or less the total number of the Gd fuel rods. At a transverse cross-section of a region upward from upper ends of the short-sized fuel rods 3, the amount of burnable poison contained in a polygonal region 10 whose vertexes are located at centers of those of the first fuel rods 3 arranged at the outermost layer is smaller than the amount of burnable poison outside the region 10. With this configuration, a critical power can be improved in consideration of both a distribution of the flow of coolant and a distribution of a thermal power in the fuel assembly.

The lower end of each of a plurality of fuel rods is supported by a fuel supporting portion of a lower tie plate. The fuel supporting portion includes a plurality of second coolant paths for supplying a coolant from below the fuel supporting portion to a first coolant path defined above the fuel supporting portion and between the fuel rods. The total cross-sectional area of all the second coolant paths is smaller than the cross-sectional area of the first coolant path. A water rod disposed between the fuel rods each includes an ascending tube path having therein a coolant ascending path having a coolant inlet port opening to a region below the fuel supporting portion, for guiding upward the coolant supplied through the coolant inlet port, and a descending tube having therein a coolant descending path having a coolant delivery port opening to said first coolant path, for guiding downward the coolant guided by said coolant ascending path and discharging the coolant through the coolant delivery port to the first coolant path. The descending tube path is so disposed outside the ascending tube path as to define a gap, through which the coolant inside the first coolant path flows, between it and the ascending tube path.

Fuel assembly and nuclear reactor

A fuel assembly is provided with a coolant ascending path for making coolant rise and a water rod having a coolant descending path for conducting the coolant. A ratio of a flow area in a coolant inlet port of the smallest in coolant ascending path 13 on the downstream side than large diameter tube portion 3E to a flow area of the largest in the axial direction of coolant ascending path 13 in large diameter tube portion 3E is set to be 0.2-20%. In the normal operation, the declination degree from the liquid level in the coolant ascending path, corresponding to the coolant flow rate of the liquid level formed in the coolant ascending path can be controlled. Further, at the time of the excess the change speed of the liquid level can also be controlled.

A fuel assembly comprises a plurality of fuel rods, tie plates for holding both ends of these fuel rods, and spacers which support these fuel rods. The spacer comprises a plurality of cells into which the fuel rods are inserted respectively, the adjacent cells being joined to each other at axial ends thereof, whereby a space between these cells being held or retained, and a plurality of loop springs held respectively on the cells. Each of the loop springs has a pair of resilient members which are located within the pair of adjacent cells and which urge the fuel rods in a radial direction, and a pair of connections which connect axial ends of the resilient members to each other. Each of the connections have a passage through which coolant flows axially and which is defined by a closed peripheral wall. The closed peripheral wall is not uniform in thickness. The pair of adjacent cells have at axial end portions of peripheral walls openings for accommodating or receiving the connections of the loop spring.

Growing community of inventors

Hitachiohta, Japan

Koji Nishida