Abstract: An intake-air temperature controlling device for an engine is provided, which includes an engine body, an intake passage, an air intake part, an intake air temperature adjuster configured to adjust air temperature taken in through the air intake part to the passage, and a controller. An operating range in which the CI combustion is performed has a lean operating range in which A/F of mixture gas formed inside the cylinder, or G/F that is a relationship between the total weight G of gas inside the cylinder and a weight F of fuel fed to the cylinder is relatively low, and a rich operating range in which the A/F or G/F is relatively high. When the engine is in the lean operating range, the controller outputs a control signal to the intake air temperature adjuster so that the air temperature is increased, as compared in the rich operating range.

Abstract: A compression ignition engine with a supercharger is provided, which includes one or more valves configured to switch a state between a first state where intake air is boosted by the supercharger and a second state where it is not boosted, a fluid temperature adjuster configured to adjust a temperature of engine coolant to be supplied to a radiator from an engine body, and a controller. When the engine operates in a high-load range, the controller controls the combustion mode to be in a compression ignition combustion mode, and causes the valve(s) to be in the first state, and in a low-load range, the controller causes the valve(s) to be in the second state. In the high-load range, the controller outputs a control signal to the fluid temperature adjuster so that a target temperature of the engine coolant is lowered than that in the low-load range.

Abstract: A traveling air introducing mechanism is provided to prevent foreign material from being caught by a pivot shaft portion of a flap while ensuring a large effective opening area of a frame. Embodiments include a traveling air introducing mechanism including a flap having a plate shape provided inside a frame to be rotatable between a position where the flap closes an opening and a position where the flap opens the opening. The flap includes a body having a plate shape, a pivot shaft portion, and a plate portion at the pivot shaft portion intersecting a direction in which the pivot shaft portion extends. The frame has on its inner surface an insertion hole into which the pivot shaft portion 12 is rotatably inserted. The plate portion is positioned between the inner surface of the frame and the body, and is sized to cover the insertion hole from the body side.

Abstract: An intake-air temperature controlling device is provided, which includes an engine body, an intake passage, a supercharger, a first passage, a second passage, an intake air flow rate adjuster, an intercooler, a pump, and a controller. The controller outputs a control signal to the pump so that coolant is supplied to the intercooler in a first operating range in which the intake air flow rate adjuster at least partially opens the first passage to supply intake air boosted by the supercharger to the engine body, and outputs a control signal to the pump so that the coolant is supplied to the intercooler also in a second operating range in which an engine load is below a given load, and the intake air flow rate adjuster opens the second passage and closes the first passage to supply the intake air to the engine body in a non-boosted state.

Abstract: A compression ignition engine with a supercharger is provided, which includes one or more valves configured to switch a state between a first state where intake air is boosted by the supercharger and a second state where it is not boosted, a fluid temperature adjuster configured to adjust a temperature of engine coolant to be supplied to a radiator from an engine body, and a controller. When the engine operates in a high-load range, the controller controls the combustion mode to be in a compression ignition combustion mode, and causes the valve(s) to be in the first state, and in a low-load range, the controller causes the valve(s) to be in the second state. In the high-load range, the controller outputs a control signal to the fluid temperature adjuster so that a target temperature of the engine coolant is lowered than that in the low-load range.

Abstract: An intake-air temperature controlling device is provided, which includes an engine body, an intake passage, a supercharger, a first passage, a second passage, an intake air flow rate adjuster, an intercooler, a pump, and a controller. The controller outputs a control signal to the pump so that coolant is supplied to the intercooler in a first operating range in which the intake air flow rate adjuster at least partially opens the first passage to supply intake air boosted by the supercharger to the engine body, and outputs a control signal to the pump so that the coolant is supplied to the intercooler also in a second operating range in which an engine load is below a given load, and the intake air flow rate adjuster opens the second passage and closes the first passage to supply the intake air to the engine body in a non-boosted state.

Abstract: An intake-air temperature controlling device for an engine is provided, which includes an engine body, an intake passage, an air intake part, an intake air temperature adjuster configured to adjust air temperature taken in through the air intake part to the passage, and a controller. An operating range in which the CI combustion is performed has a lean operating range in which A/F of mixture gas formed inside the cylinder, or G/F that is a relationship between the total weight G of gas inside the cylinder and a weight F of fuel fed to the cylinder is relatively low, and a rich operating range in which the A/F or G/F is relatively high. When the engine is in the lean operating range, the controller outputs a control signal to the intake air temperature adjuster so that the air temperature is increased, as compared in the rich operating range.

Abstract: Ultrasonic waves from a transmit device are transmitted to an object subject to measurement. A surface reflected wave propagated in a contact medium and reflected at the surface of a tube and bottom surface reflected waves passing through an oxidation layer on the tube and reflected at the inner surface of the tube are convened into electric signals. A feature extracting part 5, in consideration of a correlation relationship of energy with respect to the frequency of a received signal, based on the received signal of ultrasonic waves converted to electric signals, extracts a signal feature data determined beforehand which has a strong correlation relationship with the thickness of a measured part. Based on the extracted signal feature data, a thickness conversion part references a relationship storage part which has stored therein beforehand a function that shows a relationship between the signal feature data and the thickness of the oxidation layer, and obtains the thickness of the oxidation layer.

Abstract: 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.

Abstract: 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.

Abstract: A mean uranium enrichment of fuel rods is set to not less than 4 wt% and preferably 4.25%, a percentage in number of Gd rods to all the fuel rods is set in the range of 20 to 30% and preferably 23%, and an enrichment 4.45 wt% of the Gd rods is between a pellet maximum uranium enrichment and a pellet minimum uranium enrichment. A percentage in number of those fuel rods having a maximum uranium enrichment of 5.0% to all the fuel rods except the Gd rods is set to not less than 75% and preferably 82%. A mean uranium enrichment in the enriched fuel section except blanket regions at upper and lower end portions is 4.75 wt% and a ratio e.sub.max /e.sub.mean of the pellet maximum uranium enrichment to that mean uranium enrichment is not larger than 1.16 and preferably 1.105. Accordingly, when the maximum uranium enrichment is limited to 5.0 wt%, the mean uranium enrichment can be raised to attain mean discharged exposure not less than 45 GWd/t without causing any problems in gadolinia containing fuel rods.

Abstract: A fuel assembly comprises a plurality of fuel rods supported by an upper tie plate and a lower tie plate respectively at each of upper end portion ad lower end portion, and a channel box surrounding a bundle of the fuel rods and the lower tie plate. The fuel assembly forms a natural uranium region at lower end portion of effective fuel length portion. A wall thickness at a lower thick wall region of the channel box is thicker than the wall thickness at a region disposed upwardly from the lower thick wall region and between corner portions of the channel box. An upper end of the lower thick wall region is disposed from an upper side of the lower tie plate and downwardly from an upper end of the natural uranium region. A wall thickness at the corner portion of the channel box is thicker than the wall thickness at a middle portion of the side wall between the corner positions at the region locating upward from the lower thick wall region.

Abstract: A fuel assembly comprises a plurality of fuel rods, a lower tie plate for supporting lower ends of the fuel rods, and a channel box surrounding a bundle of the fuel rods and the circumference of the lower tie plate to thereby define a cooling water leak passage between the lower tie plate and the channel box. The fuel assembly includes a venturi provided in the lower tie plate for generating a force tending to attract the channel box toward the lower tie plate under the action of a leak stream of the cooling water passing through the cooling water leak passage. The fuel assembly also includes an arrangement provided in the lower tie plate for suppressing vibrations of the channel box caused upon an influence of the venturi.

Abstract: Each of cylindrical members composing a fuel spacer of separate cell type is formed at a edge portion thereof with a positioning notch or a positioning projection, which is located just opposite to one of fuel rod supporting projections formed on the inner surface of the cylindrical member. In manufacturing of the fuel spacer, the positioning notches or projections of the cylindrical members are engaged with the positioning projections or recesses formed on fuel spacer assembly jigs for precise and easy positioning of cylindrical members.

Abstract: A channel box and/or a spacer of a fuel assembly is a welded construction and made of a Zr-Nb-Sn alloy comprising 0.5-2.2 wt % Nb, 0.5-1.5 wt % Sn contained so as to satisfy the relation of Sn(wt %) 22.times.Nb(wt %)--3.0, and balance Zr or a Zr-Nb-Sn-Mo alloy comprising 0.5-2.2 wt % Nb, 0.5-1.5 wt % Sn contained so as to satisfy the relation of Sn(wt %).gtoreq.2.times.Nb(wt %)--0.3, 0.1-0.8 wt % Mo, and balance Zr. The welded portion, its heat affected zone and the unwelded portion of the channel box and/or the spacer have substantially the whole equilibrium phase structure.

Abstract: A method of producing a composite nuclear fuel cladding lined with a liner of high purity zirconium characterized in that a raw material of zirconium sponge disposed in a hearth cavity is irradiated with an electron beam while controlling an amount of heat per unit volume (w.sec/mm.sup.3) according to an oxygen removal rate of the raw material determined by oxygen concentration of the raw material and a target oxygen concentration of an ingot for a liner to be refined, and zircaloy cladding is lined with the liner. The hearth cavity has a preferable shape in which the ratio of the cavity surface to the cavity volume is 0.20 mm.sup.-1 or larger.

Abstract: In a process for producing a zirconium-based alloy in which after the zirconium-based alloy is subjected to hot plastic working, it is subjected to cold plastic working and then to annealing and these steps are repeated at least twice, the present invention provides a process for producing a zirconium-based alloy characterized in that after the alloy is subjected to solid solution treatment in which it is heated to a temperature within the range including the .alpha. phase and the .beta. phase of the alloy, or within the range of the .beta. phase and is then quenched, cold plastic working is effected at least twice.

Abstract: In a process for producing a zirconium-based alloy in which after the zirconium-based alloy is subjected to hot plastic working, it is subjected to cold plastic working and then to annealing and these steps are repeated at least twice, the present invention provides a process for producing a zirconium-based alloy characterized in that after the alloy is subjected to solid solution treatment in which it is heated to a temperature within the range including the .alpha. phase and the .beta. phase of the alloy, or within the range of the .beta. phase and is then quenched, cold plastic working is effected at least twice.

Abstract: A high-purity metal member is produced by charging raw material such as sponge zirconium into a cavity of a mold such as a hearth under a vacuum atmosphere; irradiating the material with electron beams to melt it at a limited area of the cavity while forming a molten metal pool and irradiating the pool with the electron beam thereby elevate the molten metal pool to evaporate away impurities therein; and shifting the mold relative to the electron beams to provide a high-purity metal member. The metal pool is limited in its size and irradiated high energy density electron beams so that the temperature is raised whereby the impurities are easily evaporated away. The mold may have an annular cavity. In case of high-purity sleeve formation, the electron beams are irradiated onto the raw material while rotating the mold so that melting and solidification appear in a circumferential direction to be repeated. The impurities are repeatedly exposed to the electron beams.