Showing papers on "Fin (extended surface) published in 1982"

Heat-Transfer Augmentation in Rod Bundles Near Grid Spacers

Abstract: Heat-transfer augmentation by straight grid spacers in rod bundles is studied for single-phase flow and for post-critical heat flux dispersed flow. The heat transfer effect of swirling grid spacers in single-phase flow is also examined. Governing heat-transfer mechanisms are analyzed, and predictive formulations are established. For single-phase flow, the local heat transfer at a straight spacer and at its upstream or downstream locations are treated separately. The effect of local velocity increasing near swirling spacer is considered. For post critical heat flux (CHF) dispersed flow, the heat transfer by thermal radiation, fin cooling, and vapor convection near the spacer are calculated. The predictions are compared with experimental data with satisfactory agreement.

Efficient Sequential Solution of the Nonlinear Inverse Heat Conduction Problem

Abstract: The nonlinear inverse heat conduction problem is the calculation of surface heat fluxes and temperatures by utilizing measured interior temperatures in opaque solids possessing temperature-variable thermal properties. The most widely used numerical method for this problem was developed by Beck. The new sequential procedure presented here reduces the number of computer calculations by a factor of 3 or 4. The general heat conduction model used permits treatment of various one-dimensional geometries (plates, cylinders, and spheres), energy sources, and fin effects. The numerical procedure is illustrated for finite differences, but the basic concepts are also applicable to the finite-element method. Detailed descriptions of the computational algorithms are given and a nonlinear example is provided.

Heat transfer by free convection between two parallel flat plates

Abstract: A few numerical analyses of the free convection between two heated parallel plates have been carried out without using the boundary-layer approximation. In this paper, an approach that can determine the flow rate with consideration of the pressure drop is proposed. As an example of the calculation, the method is applied to Kettleborough's model. In addition, a comparison is made with Kettleborough's and Aihara's results.

Natural and Mixed Convection Heat Transfer Around a Horizontal Cylinder within Confining Walls

Abstract: Laminar natural and mixed convection around a heated cylinder placed within confining walls is investigated numerically. The numerical scheme involves the use of a cylindrical network of nodes in the vicinity of the cylinder with a Cartesian mesh covering the remainder of the flow domain. Results are obtained for the streamlines, isotherms, and heat transfer coefficients. Effects of varying the ratio of width across the walls to cylinder diameter are also investigated. The results obtained are of direct use, for instance, in the design of certain thermal energy storage devices and ocean thermal energy conversion units under investigation.

Heat exchanger having uniform surface temperature and improved structural strength

Abstract: A plate-type heat exchanger having uniform surface temperature and improved structural strength is disclosed, which may be used as a structural support member for an object to be temperature controlled, and which provides a surface having an exceptionally uniform temperature for either heating or cooling the object. The heat exchanger includes a fin pad and a machined plate having a fluid passage therein, as well as other structural frame and support members. The major circuit flow direction of the fluid in the passage is perpendicular to the major longitudinal fin direction of the fin pad in the preferred embodiment. All components of the heat exchanger are of material having good thermal conductivity and structural strength, and the components are brazed or otherwise secured together to provide good thermal conductivity and structural reinforcement throughout.

A Numerical Study of the Effect of a Vertical Temperature Difference Imposed on a Horizontal Enclosure

Abstract: Results are presented for a numerical investigation of the flow and heat transfer in an enclosure subjected to comparable horizontal and vertical temperature differences. This problem is an extension of the unidirectional heat flow case and also has applications in the area of design. The regime characterized by dominant horizontal heat flow as well as that of dominant vertical heat flow are delineated. A stabilizing vertical temperature difference is found to decrease the vertical velocities next to the hot wall, but actually to increase the horizontal heat transfer. An interesting result is that for a destabilizing temperature difference, horizontal heat transfer can effectively occur from the cold wall to the hot wall if the vertical heat flux is high enough. Finally, actual heat transfer data are presented for a square enclosure and a Prandtl number of 0.71. A qualitative comparison with earlier experiments is made.

Wet/dry steam condenser

Abstract: A wet/dry steam condenser in accordance with the present invention includes two spaced-apart, vertically aligned groups of heat pipes with each group having the lower, evaporator sections of their respective heat pipes exposed to the interior of an associated, longitudinally extending steam-receiving plenum. The upper, condensing section of each heat pipe is provided with fin structures and can be selectively cooled by a fan-induced air flow and/or deluge water supplied from either a flood water trough and/or a spray-head assembly.

An Analytical Investigation of Fin Lines with Magnetized Ferrite Substrate.

Abstract: : This paper presents an analysis method of the fin line on a magnetized ferrite substrate. The method is based on the application of the network analysis techniques of electromagnetic fields (8), (9) in conjunction with the Galerkin's procedure. The determinantal equation for the propagation constant of a unilateral fin line is obtained via matrix formulation. Convergence checks are performed by increasing the number of basis functions for the representation of the aperture field. Some representative numerical results are included in the paper. The method of analysis is quite general and is applicable to other types of fin line structures containing anisotropic media.

Heat exchanger fin element with dog-bone type pattern of corrugations

Abstract: An improved fin element adapted for use in a fin and tube type heat exchanger core assembly, the improved fin element having a plurality of tube openings extending therethrough and having a "dog-bone" type pattern of corrugations extending substantially over the entire planar surface thereof, the corrugated pattern forming a uniform, discontinuous, six-sided configuration about each respective tube opening for altering the fluid flow characteristics across the fin in such a manner as to enhance its heat transfer capability The particular pattern of corrugations utilized on the subject fin element effectively induces turbulent flow thereacross; it causes circulation of the fluid medium flowing thereacross to the downstream side of the tubes extending therethrough; and, it effectively reduces the thickness of the boundary layer associated therewith to achieve increased heat transfer performance without a corresponding increase in fluid flow resistance

Fuel control apparatus for an internal combustion engine

Abstract: A fuel control apparatus is mounted directly on the intake tube of an internal combustion engine by means of a heat dissipating fin having a fuel passage extending therethrough The apparatus includes a control device for controlling the operation of a fuel injection valve in accordance with various parameters such as the quantity of incoming air to the engine and the temperature of the engine The heat generated by the control device is dissipated to the fin and the fuel passing through the passage and heat insulating material is interposed between the fin and the intake tube The fuel passage extending through the fin may carry fuel to or from the fuel pressure controller and the fuel tank or may carry fuel from the fuel pressure controller to the fuel injection valve

Device for heat emission

Abstract: PURPOSE:To enable to change the amount of heat emission automatically with respect to the temperature variation of a heating body by the strong power of transformation at the critical temperature of a form memorizing alloy. CONSTITUTION:When the temperature of the heating body begins to rise, the temperature of a spring 5 consisting of the form memorizing alloy is risen also and when it exceeds the critical temperature, the power of transformation is created in the spring 5, impresses the force to a heat emitting fin 2 into the direction vertical to the main frame 1 of the heat emitting plate to rotate the heat emitting fin 2 about the axis 3 which enables to stand up it in vertical to the heat emitting plate main frame 1. A heat emitting area is small and the amount of the heat emission may be controlled upon the kick-off of the heating body or the like, therefore, the speed of temperature rise upon the kick-off of the same is high. When the temperature of the heating body is risen, the heat emitting fin 2 is stood up by the effect of the spring 5 and thereby increasing the heat emitting area and the amount of the heat emission also.

Heat accumulating device

Abstract: PURPOSE:To make a device compact and to reliably prevent a latent heat accumulating material from being brought into an overcooling state without consuming surplus energy, by a method wherein a part containing a connection part between a branch pipe and a container is formed by a material having thermal conductivity lower than that of the container, and the other part is formed by a material thermal conductivity higher than that of the container. CONSTITUTION:With a switch 6 turned ON, a heater 5 is charged with a current, a metallic container 2 is heated, and heat is accumulated in a heat accumulating material 4. In this case, the heat of the heater 5 is transferred to a branch pipe 8 through the container 2, but since the root part of the branch pipe 8 is a low thermal conductivity material part 9, a quantity of heat transferred to the branch pipe 8 is extremely low. A high thermal conductivity material part 10 is located to the forward part of the low thermal conductivity material part 9, and besides since a radiation fin 11 is mounted, heat possessed by a heat accumulating material 4 in the branch pipe 8 is rapidly dissipated in the surrounding air. As noted above, an amount of heat flowing out to the surrounding air can be set to a high value as an out of heat coming in the branch pipe 8 is suppressed. When, after completion of heat accumulation, the heat accumulating material 4 is cooled to take out heat, the heat accumulating material 4 can be reliably prevented from being brought into an overcooling state.

Thermal resistance measuring method of semiconductor device

Abstract: PURPOSE:To exactly discriminate the variance of thermal resistance in a short time, by applying a great deal of heat to a semiconductor from the outside, and measuring a temperature in the inside of a chip. CONSTITUTION:A radiation fin 4 is heated by an infrared lamp from the outside. After the lamp has been lighted, a temperature of a chip is measured by utilizing P-N junction in a chip 2 after some time has elapsed. Heat which has been applied by the lamp 6 is transmitted through a path as R3 C3 R2 R1 C1, being scarcely influenced by a capacitor C4 of an equivalent circuit of a thermal flow. Accordingly, the higher a temperature of the chip rises after (t) time, the lower the thermal resistance is. When the quantity of heat from the lamp is increased, the quantity of heat passing through the thermal resistance Ri (i=1-3) is increased, a temperature difference is increased even if a difference of the thermal resistance is small, and the detecting sensitivity becomes high. Also, heat passes through almost all radiation routes which become important when they are used actually, and attains to the chip 2, therefore, the decision is executed very exactly.

Storage type hot water supplier

Abstract: PURPOSE:To make it possible to supply hot water of a large capaciy with low input ability by separating a hot water storage tank from a heat source part and disposing a pump capable of controlling the quantity of circulated hot water in a circuit introducing high temperature water from the lower part of the hot water storage tank to the substantially middle part of the hot water storage tank via a heat exchanger CONSTITUTION:A burner 1 and a heat exchanger 2 of a fin piped type heated by the operation of this burner 1 are encircled by a casing 3, and disposed beneath a hot water tank 7 To one end of the casing 3 is connected an exhaust cylinder 4 having at its tip end a fan 5 and an exhaust top 6 One end of the heat exchanger 2 is connected to a water supply port 8 beneath the hot water storage tank 7 through a pump 9 capable of varying the quantity of circulation, and another end of the heat exchanger 2 to a heated water outlet port 11 above the hot water storage tank 7 A hot water outlet pipe 10A provided with a number of small holes 10B as an extension of a hot water outlet pipe 10 is disposed at the outlet port 11 within the hot water storage tank 7 The ON/OFF of the above burner 1 is controlled based on the output signal from a temperature detector 12 provided at the upper part of the hot water storage tank 7

Ink supply method, inking apparatus and roll

Abstract: PURPOSE:To miniaturize an inking apparatus and to stably supply ink while reducing the load of a motor, by using heat pipes as the kneading roll, the leveling roll and the doctor roll of the inking apparatus. CONSTITUTION:A heat pipe 20 is used as a roll having a metal surface used in either one of the kneading roll, the leveling roll and the doctor roll in the inking apparatus of an offset or letterpress printing press. When heat is applied to one end of said heat pipe, for example, the part of the fin 23 thereof, it is conducted to the hollow body 21 at the part contacted with the fin 23 and a hydraulic fluid 25 to evaporate said hydraulic fluid. The gas reaching the other end having a lower temp. is condensed at the gas-liquid interface to release latent heat and heat is conducted to the heat absorbing body (ink) of the outside through the hollow body.

Heat dissipating lead connector for semiconductor packages

Abstract: A heat dissipating connector for semiconductor package leads is disclosed. The body of the connector is comprised of two oppositely facing fingers formed from a unitary strip by making a 180 degree bend transverse to the longitudinal axis of the strip. A heat dissipating fin is formed integrally with an edge of one of the fingers, and protrudes substantially perpendicular to the vertical centerline of the heat dissipating connector body. In its installed condition, the facing surfaces of the fingers engage a semiconductor package lead with a spring force urged from the spring configuration of one of the fingers. The integrated circuit electrical lead, when mounted between the engaging surfaces of the oppositely facing fingers, is gripped in place, thereby maintaining a good heat and electrically conductive relationship therewith.

Continuous manufacturing method and apparatus for heat collecting plate for solar collector

Abstract: PURPOSE:To improve production capacity and recovery of titled heat collecting plate by arc welding a lapped part obtained by feeding fin material and pipe material at the same speed and in the same direction successively from above the fin and after quenching, giving corrugated pattern to the fin part. CONSTITUTION:While feeding 10 a copper hoop material W from an uncoiler 11, pipe material P is fed 20 at the same speed and in the same direction with the fin material and sent to a lap welding device 30. In the device 30, the fin material W and the pipe material P are lapped longitudinally. While carrying in a body, arc welding 34 is made successively from the fin material side and quenched 40 successively. Next, corrugated pattern is given to the fin of the heat collecting body thus formed, the pipe part is made straight by a correcting device 30 to complete the titled heat collecting plate. In the figure, 60 indicates a travelling cutting device and 70 shows a product chuter.

Manufacture of semiconductor device

Abstract: PURPOSE:To realize simultaneous bonding of a heat radiating fin and a semiconductor device to a lead frame head by a method wherein plate shaped head with through holes is positioned on a heat radiating fin and then applied a coating of an adhesive agent before a semiconductor device is placed on said head and pressedly bonded under heat. CONSTITUTION:A lead frame head 12 provided with some through holes represented by 10 and 10' is placed on a heat radiating fin 7. Next, an adhesive 20 is paintedly applied to the surface of the head 12. The adhesive 20 fills up the vacancies 10a and 10a' formed by the heat radiating fin 7 and the through holes 10 and 10'. Next, a semiconductor device 3 is installed upon the head 12 and then heated under pressure and, thanks to the adhesive 20a and 20a' filling said vacancies, the semiconductor device 3 is bonded to the head 12 simultaneously with the heat radiating fin 7. Finally, by an ordinary wire bonding technique, leads 6 and 6' are connected to the bonding pads 3a and 3b. The entirety is then resin molded for the completion of the device.