Hitachi, Ltd.

Iwao Harada

Yasuo Fujitani

Kazuhiko Hiraoka

Michihiko Aizawa

Morishige Hattori

Masakazu Matsumoto

Hideshi Ooba

A railway vehicle includes an air intakeprovided at a nose portion of a leading vehiclean air tank (reservoir)for storing intake air, and an air outletby which air is sucked in (breathed in) during entry of the leading vehicle to a tunnel and discharged within the tunnel, so as to reduce the pressure generated at the nose portion and to cut down micropressure waves. When the nose of the leading vehicleenters a tunnelan intake control valveof the air reservoir, depressurized to below atmospheric pressure (1 atm), opens to take in air through an air inletvia a pathinto the air reservoirWhen the whole leading vehicle enters the tunnel, the intake control valvecloses, and air is discharged through the outletvia a pump

Railway vehicle and method for operating vehicle

A steam condenser according to the present invention has a tube nest which has a massed region of cooling tubes and a plurality of tube bundles with flow passages. A noncondensable gas extracting tube is arranged among the cooling tubes in the massed region. A cooling unit or a steam condensing chamber for condensing steam contained in noncondensable gases which are extracted from the noncondensable gas extracting tube is arranged in the massed region. A discharge flow passage is formed at least partially in the tube next so as to enable the noncondensable gases from the cooling unit or the steam condensing chamber to be discharged outside of the condenser, whereby condensing efficiency of the steam contained in the noncondensable gases which flow into the cooling unit or the steam condensing chamber is improved.

Condenser and power plant

A tube nest of a compact condenser has flow passages, tube bundles and a noncondensable gas extracting opening. The tube nest is installed in a vessel having a bottom surface. The tube nest is spaced from the bottom surface and the side walls of the vessel so that stream is able to flow from every direction into the tube nest at a reduced steam velocity. The extracting opening is disposed below the center of gravity of the outer circumference, and the plurality of flow passages extend from the outer circumference toward the extracting opening. Each flow passage has open outer end on the outer circumference and the width of each flow passage increases toward the open outer end. The area ratio and the length of the flow passage increase toward the center axis of the tube nest. The result is a compact condenser capable of reducing pressure loss and of efficiently removing noncondensable gas.

To provide a high speed vehicle having a nose shape which reduces a pressure gradient of a micro pressure wave and secures the capacity necessary for each of the driver's cab and the passenger's cabin and the visibility necessary for driving, a nose shape is proposed having a tip region, an intermediate region and a rear region, respectively. The change rate of the sectional area from the tip toward the rear end is maximal in the tip region and progressively decreases towards the intermediate region and the rear region.

Railway vehicle with micro pressure wave reducing contour for tunnel

A heat exchanger for condensing into liquid phase a vapor containing non-condensable gas components through heat exchange with a heat exchanging medium has a vessel having a vapor inlet for receiving the vapor containing the non-condensable gas components and a discharge port for the non-condensable gas components. The heat exchanger further has a tube nest disposed in the vessel and having a plurality of tubes through which the heat exchanging medium flows. The vapor containing non-condensable gas components flows towards the discharge port across the tube nest so as to be condensed into liquid phase through heat exchange with the heat exchanging medium flowing through the tubes, so that the non-condensable gas components are separated from the liquid phase and flow towards the discharge port. The tube nest is constructed to create a change in the dynamic pressure of flow of the vapor towards the discharge port to cause such a static pressure distribution in the heat exchanger that a lower static pressure is established in a region where the discharge port is provided than in a region where the vapor inlet is provided.

Growing community of inventors

Mito, Japan

Iwao Harada