Showing papers on "Micro heat exchanger published in 1969"

The rotating heat pipe - A wickless, hollow shaft for transferring high heat fluxes.

Abstract: Rotating wickless hollow shaft heat pipe utilizing centrifugal acceleration for return pumping of condensate and transferring high heat fluxes

A Compact Perforated-Plate Heat Exchanger

Abstract: Claude-cycle cryogenic refrigerators require counterflow heat exchangers having an extremely high thermal effectiveness. Miniature systems also require very small heat exchanger volume, which is difficult to achieve along with high effectiveness. Such heat exchangers must possess all of the following characteristics.

Method and apparatus for two-phase heat exchange fluid distribution in plate-type heat exchangers

Abstract: Method and apparatus for heat exchanging a gaseous fluid and a liquid fluid with a third heat exchange fluid by a plate-type heat exchanger in a manner permitting variations of the gaseous mass flow rate relative to the liquid mass flow rate without relative maldistribution of the two fluid phases within the heat exchanger passages. Between the plates within the heat exchanger core, the gaseous and liquid fluids are separately distributed across the width of the heat exchanger. Only after the gaseous and liquid fluids have been thus uniformly distributed within the passages are they combined and passed in heat exchange relation with the third heat exchange fluid. The problems associated with relative maldistribution of the two fluid phases which normally accompany conventional arrangements for distributing a two-phase fluid across the width of a plate-type heat exchanger are thus avoided. Four embodiments of the invention are described and shown.

Nuclear reactor with heat pipes for heat extraction

Abstract: A nuclear reactor with a heat extraction system comprising two groups of heat pipes which extend through the reactor core and which deliver heat to heat sinks disposed outside the core. All pipes of one group being parallel, the two groups are arranged in a mutual right angle relation and they intersect each other.

Vertical staggered surface feedwater heater

Abstract: A multipass vertical heat exchanger constructed to provide different lengths of heat exchange tubing for carrying liquid on different passes through the heat exchanger. The construction avoids unnecessary flooding of heat exchange tube surface with steam condensate in the higher passes of the heat exchange tubing through the heat exchanger.

Determination of properties of capillary media useful in heat pipe design.

Abstract: Wick capillary pressure, permeability and burnout heat flux measurements to provide data for heat pipe design

Method of making expanded integral fin sheet metal tubing for use in heat exchangers

Abstract: A SHEET METAL TUBING HAVING INTEGRALLY FORMED WEB SECTIONS WHICH ARE SLIT TO FORM FINS. THE FIN SURFACE AREA IS INCREASED BY CORRUGATING THE WEB SECTIONS PRIOR TO SLITTING THEM INTO FINS. AFTER SLITTING, THE FINS ARE FLATTENED OR SHAPED AS DESIRED, AND THEN TWISTED OR BENT TO FORM THE DESIRED ARRAY. THE SHEET METAL TUBING MAY BE FORMED INTO A VARIETY OF SHAPES SUCH AS COILS FOR USE IN HEAT EXCHANGERS IN APPLICATIONS SUCH AS REFRIGERATORS.

Distributing a two-phase flow to plate heat - exchangers

Abstract: A distributor pipe on the heat exchanger inlet surface distributes the phase flow to the individual heat exchanger passages. The two-phase flow is fed sideways into the distributor pipe, and a baffle plate inclined and/or curved to the distributor axis forms at least one wedge-shaped space between the heat exchanger inlet surface and the distributor pipe wall. Use relates to heat exchanger between streams of different materials without their mixing together.

Control of an air-cooled heat exchanger

Abstract: An air-cooled heat exchanger provided with a reversible pitch fan is controlled against excessive temperature swing in the material being cooled by the use of temperature-sensing elements and control circuitry which set the pitch of the fan for forward flow, reverse flow or feathering

A study of the effects of internal rib and channel geometry in rectangular channels. Part II. Heat transfer

Abstract: Heat transfer and pressure drop data were taken on commercial plate heat exchange equipment. Nusselt and Euler correlations were determined for each of the six commercial heat exchangers investigated. These correlations were combined to establish a single heat transfer-pressure drop relationship for any plate type of heat exchanger channel. The results of this investigation were tested by using the correlations developed in Part I of this series to predict pressure drop data for the commercial unit based on their channel geometries. These predicted pressure drops were then used with the results of this part of the series to predict and compare heat transfer data. The correlations developed in this work allow one to determine the heat transfer characteristics in a ribbed rectangular channel from the pressure drop characteristics of the channel in question.

Liquid metal heat exchangers with pressure absorbing means

Abstract: Heat exchangers of the type using liquid sodium as a heat exchange fluid contain chambers inside their casings which are susceptible of collapse and/or breakage for the purpose of limiting the consequences of a reaction of sodium with water and steam in case of damage or failure to the means separating the two fluids.

An experimental and analytical study of water heat pipes for moderate temperature ranges

Abstract: Experimental and analytical study of water heat pipes for 200 to 350 deg F temperature range

Performance of a wick-limited heat pipe.

Abstract: Wick-limited heat pipe performance, discussing maximum, steady heat transfer rate and transient response

Heat transfer to solid‐vapor mixtures of cryogens below their triple points flowing through heated tubes

Abstract: Wall temperatures and heat transfer coefficients for solid-vapor mixtures of para hydrogen and nitrogen flowing in heated tube

Improvements in or relating to Heat Exchangers.

Abstract: 1,158,322. Tubular heat exchangers; surface condensers. G. & J. WEIR Ltd. 27 July, 1966 [7 Oct., 1965], No. 42697/65. Heading F4S. The header 1 of a shell-and-tube heat exchanger in which the tubes 2 are U-shaped is of toroidal configuration. The header is formed of two annular sections 1a, 1b welded together at 5, 6, one section 1a acting as a tube sheet and the other section 1b being formed with inlet and outlet ports 7, 8 and access covers. The tube sheet 1a may be formed with a plane face (Figs. 7, 8, 12) and be divided along a diameter into inlet and outlet sections, or may be formed with an annular plane surface 3 and a frusto-conical surface 4, one acting as an inlet section and one as an outlet section. In use, boiler feedwater is heated as it flows through the tubes, by steam which enters the casing through a port 15, is desuperheated in a chamber 26, and condensed in the main chamber 31, the condensate being cooled in a third chamber 27 and the chambers being separated by partitions 45. Baffles 20, 21 direct the steam in a sinuous path, in cross flow to the tubes 2.

Improvements relating to Heat Exchangers.

Abstract: 1,158,981. Tubular heat exchangers; steam reheaters. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. 16 Feb., 1967 [22 Feb., 1966], No. 7679/66. Headings F4A and F4S. In a heat exchanger used, e.g. as a steam reheater having a tube bundle 26 composed of sets of tubes extending between inlet and outlet header structures 20, 25 respectively, each header structure is subdivided by a series of tube plates 22, 23, 24 into separate header compartments 17, 18, 19, successive tube plates being penetrated by a decreasing number of tube sets so that each set opens into a respective header compartment. The heating fluid, e.g. steam at super-critical pressure enters through inlets 11, 12 and 13 in the header compartments 17, 18 and 19 and leaves through similar compartments in the outlet header 25. The fluid to be heated, namely steam, after entering the U-shaped sheath 21 enclosing the tubes 26 at 28, flows countercurrently between the tubes to exit at 29. The tubes of the sets are interspersed within the tube bundle 26. The heat exchanger may alternatively be used as a double wall heat exchanger wherein only two sets of tubes are used to make up the tube bundle. Water is passed through one set of tubes to be heated by hot sodium or sodium/potassium alloy passed through the other set, thus producing steam; an intervening heat exchange liquid is provided in the sheath 21 to surround all the tubes.

Integral irradiance factors of multirow heat exchangers

Abstract: A procedure for determining irradiance factors of multirow tubular heat exchangers is proposed. Numerical values of these factors are obtained for heat exchangers with a number of rows n ≤ 7.

Heat transfer and hydraulic resistance in wire-net packing

Abstract: In this article, we present the results of studying the heat-transfer processes and hydraulic resistance in small wire-nets used as regenerator packing. Three types of woven wire-nets were used: Nos: 004, 0071, and 025. We used the method of indirect determination of heat-transfer coefficients, which is based on the well-known solution of the equations of fixed-bed heating by an incompressible-l iquid stream in the absence of heat exchange with the surrounding medium, as given by T. Shuman [8].