Mitsubishi Heavy Industries Limited

Mitsubishi Hitachi Power Systems, Ltd.

Mitsubishi Aircraft Corporation

Mitsubishi Power, Ltd.

Yuichi Kanemaki

Kazuhiro Domoto

Hiroshi Suganuma

Daigo Watanabe

Hiroyuki Nakaharai

Masaaki Fujita

Shingo Kawano

Ushio Komoda

Takumi Tokiyoshi

Atsushi Fujii

Fumitoshi Sakata

Shintaro Matsumoto

Hiroyuki Ohyama

Toshiyuki Umemoto

Yasuharu Chuman

Yoshinori Yamasaki

Ichiro Ohtsu

Takuya Fukahori

A heat transfer tube for a boiler, an interior of the heat transfer tube having a supercritical pressure and being configured to have a heating medium flow therethrough, includes: a groove portion defined on an inner circumferential surface and having a spiral shape extending continuously toward a tube axis direction; and a rib portion extending continuously and protruding inward in a radial direction by the groove portion of the spiral shape. In a cross section taken along the tube axis direction, a width of the groove portion in the tube axis direction is defined as Wg, a height of the rib portion in the radial direction is defined as Hr and a tube outer diameter is defined as D, and the width Wg of the groove portion, the height Hr of the rib portion, and the tube outer diameter D satisfy Wg/(Hr&#xb7;D)&#x3e;0.40.

Heat transfer tube including a groove portion having a spiral shape extending continuously and a rib portion extending continuously and protruding inward by the groove portion

A fuel tank that stores fuel to be fed to a fuel supply destination through a pipe, wherein a whole or a portion of a storage fuel contact portion in contact with the fuel within the fuel tank is subjected to surface finishing for imparting hydrophilicity.

Fuel tank, fuel pipe, and aircraft

A method of extending a life expectancy of a high-temperature piping, includes removing a heat insulation material which covers the piping having a high creep rupture risk, and lowering an outer surface temperature of piping, wherein a width of an exposed portion obtained is twice or more a distance from a peeled-off end portion of the exposed portion to a portion where a compressive stress is asymptotical to 0 after a change in stress between a tensile stress and the compressive stress occurring in the piping due to the removal of the heat insulation material is made from the tensile stress to the compressive stress, and the distance is calculated based on the following formulae, &#x3b2;x=5, here, &#x3bd; is a Poisson's ratio, a is an average radius of the piping, and h is a plate thickness of the piping.

Method of extending life expectancy of high-temperature piping and life expectancy extension structure of high-temperature piping

Provided is a boiler structure that allows for appropriate flow-rate distribution for each furnace wall by using a simple configuration without any moving parts in a wide thermal-load range of a furnace from a partial load to a rated load. In a boiler structure having a furnace water-wall formed of multiple boiler evaporation tubes and configured to generate steam by heating water inside the furnace when the water that is pressure-fed to the boiler evaporation tubes flows inside the tubes, the boiler structure includes a pressure-loss adjusting section, for an internal fluid, provided in an outlet connection tube that connects outlets of water walls obtained by dividing the furnace water-wall into multiple parts.

Boiler structure

Provided is a boiler structure with which, by reducing the pressure drop in boiler evaporation tubes correspondingly to the heat flux, which varies in accordance with the distance in the boiler height direction, it is possible to reduce auxiliary power for a water feed pump and so forth, in addition to improving the flow stability and the natural circulation characteristics. The boiler structure includes a number of boiler evaporation tubes that are arranged on a wall surface of a furnace and that form a furnace wall, water pumped into the boiler evaporation tubes being heated in the furnace during flowing inside the tubes to produce steam, wherein the boiler evaporation tubes are formed by connecting tubes of a plurality of types, in which tube wall thicknesses are adjusted on the basis of furnace heat flux such that the higher the furnace heat flux in a region is, the smaller the tube inner diameter becomes.

Growing community of inventors

Tokyo, Japan

Yuichi Kanemaki