Abstract: In an inverter device comprising a main circuit section which switches a power at high speed, having a switching element and a smoothing condenser for smoothing the power supplied to the switching element, and a logic section for controlling the main circuit section, a shielding member is disposed between the main circuit section and the logical section. The shielding member includes a combination of a heat shielding member and an electromagnetic shielding member so as to protect the logic section from heat, electromagnetic noise, and vibration generated in the main circuit section for improving reliability of the inverter device.

Abstract: A method for producing a heat transfer tube for single-phase flow having rows of discontinuous projections formed on the inner surface thereof along one or more spiral curves. Each projection has a circular, elliptic or a similar cross-section constituted by smooth curves at any desired height including the bottom thereof. The cross-sectional area of the projection progressively decreases towards the top of the projection.

Abstract: A heat transfer tube has at least a row of projections provided on its inner surface at regular intervals along a spiral curve thereof. The row of projections are formed by plastic deformation of part of the heat transfer tube, which is effected by pressing a rolling disc having projections against the outer surface of the heat transfer tube. The projections have smooth curved surfaces. The height of the projections ranges from 0.45 mm to 0.6 mm, their pitch along the spiral curve ranges from 3.5 mm to 5 mm, and their pitch in the axial direction ranges from 5 mm to 9 mm.

Abstract: A heat transfer tube for single-phase flow having rows of discontinuous projections formed on the inner surface thereof along one or more spiral curves. Each projection has a circular, elliptic or a similar cross-section constituted by smooth curves at any desired height including the bottom thereof. The cross-sectional area of the projection progessively decreases towards the top of the projection.

Abstract: A method of producing a heat transfer wall, including a plurality of minute tunnels parallelly extending and spaced a minuscule distance from each other under an outer surface of the wall in contact with liquid, and a plurality of tiny hole portions formed at the outer surface of the wall above the tunnels and located at regular intervals along the tunnels to maintain same in communication with the outside. Each hole portion includes a projection located in the hole portion including a hole itself and extending from the vicinity of the hole portion into the hole portion in a manner to traverse same, so that a flow of liquid into the tunnels and a flow of vapor out of the tunnels can be optimally regulated by the projections to enable the heat transfer wall to exhibit a high heat transfer performance.

Abstract: A heat transfer pipe for use in a heat exchanger such as air conditioner, freezer and boiler, wherein grooves are formed in the inner wall surface of the pipe, which are by far finer in size than the grooves that have been provided for the purpose of increasing the heat transfer area in general, and slanting relative to the axis of pipe, to thereby improve the heat transfer rate without increasing the pressure loss caused to the fluid flowing through the pipe.