Valery M. Kiseev

Ural Federal University | UrFU · Department of condensed matter physics and nano dimensional systems

Possible configurations of loop heat pipe evaporators have been analyzed, and the current state of experimental and theoretical studies on the choice of their capillary structures with a real pore size distribution function has been presented. On this basis, a methodology for selecting capillary structures for the primary and secondary loop heat pi...

Abstract. The deformation behavior of capillary porous (CP) Ni and CP Ti is examined under uniaxial compression in air, water, and ethanol. CP metals contained inert liquids such as H20 and C2H5OH are used as the heat pipes' active elements in space applications. The samples for mechanical testing were isostatic compacting and vacuum annealing (por...

Some configurations of cooling systems based on two-phase loops with control of the fl ow rate of the liquid and steam in them as well as experimental data obtained with these systems are presented. A model of an ejector-assisted loop heat pipe has been developed, and the results of calculations with it were compared with the corresponding experime...

Heat transfer devices based on the two-phase loops (TPL) technology can convert heat and kinetic energy of steam jet condensation into motive power for circulation of working fluid. TPL systems with capillary pumps can be used for transferring heat in the direction of the gravity force. This paper presents some configurations of TPL systems with li...

An extensive development of two-phase thermal control systems based on two- and multi-phase devices (standard heat pipes, loop heat pipes, heat switches, etc.) offers a potential to assume an increasingly important position in the instrumental thermal control for a number of space and earth applications. However, experimental data regarding long-li...

This research focuses on two-phase thermal control systems, namely loop thermosyphons (LTS) filled with nanofluids, and their use as LED cooling devices. The behavior of the fluid in the thermosyphons and the mechanisms explaining the possible impact of nanoparticles on thermal properties of the working fluid as well as the processes in the LTS are...

Extensive development of two-phase thermal control systems on the basis of two-and multi-phase devises (Heat pipes, Loop Heat Pipes and others) offers potential to occupy an increasingly important position for instrument thermal control in many space and earth applications. However, there are not enough experimental data on the long life test for s...

To validate proposed axially grooved heat pipe, designed to work with acetone, comparative characterization tests have been conducted for two heat pipes, having the same profile height of 19.1 mm, and length of 730 mm. First heat pipe is charged with acetone and has unique core however the second heat pipe, charged with ammonia, has two cores. Both...

Extensive development of the light-emitting diode (LED) devices on the basis of LED matrix offers capabilities to occupy LED at the top place for the street and industrial lighting as one of the most reliable and energy-efficient devices. However, there are not enough experimental data on the optimization of the cooling systems for LED devices. Tra...

Extensive development of the light-emitting diode (LED) devices on the basis of LED matrix offers capabilities to occupy LED an increasingly important place for the street and industrial lighting as more reliable and energy-efficient. However, there are not enough experimental data on the optimization of the cooling systems for LED devices. Traditi...

Loop Heat Pipes (LHP) and Heat Pipes (HP) are used in the thermal management of electronic devices with high-density heat dissipation. In these two-phase thermal devices, the key component is the capillary structure (CS) that pumps the working fluid using the capillary forces generated by the meniscus, which is formed due to evaporation. The perfor...

Loop heat pipes (LHPs) and other two-phase heat transfer devices are used in the thermal management of electronic devices with high density of heat dissipation. In these two-phase thermal devices, the key component is the capillary structure (CS) that pumps the working fluid using the capillary forces generated by the meniscus, which are formed due...

The problems of optimizing the evaporators of contour heat pipes with respect to the thickness of the capillary structure barrier wall, geometry of the vapor generation zone, as well as the dimensions and disposition of the system of vapor-discharge channels are discussed.

The problem on optimization of geometrical dimensions of vaporization zone of contour thermal pipeline is experimentally investigated by the example of one real sample. Optimization of thickness of fine-pore capillary structure cut-off wall as well as optimization of dimensions and a number of exhaust channels are considered. Data obtained are comp...

The processes of contact resistance formation nickel sintered capillar structures were experimentally studied. Fine porous structure was selected to isolate precisely the contact constituent of total electric conductivity. The electric conductivity was measured throughout the whole period from mechanical compaction of powder to final sintering with...

A procedure is described and principal results are presented for an experimental comparison of the thermodynamic efficiencies of the classical evaporation scheme in capillary structures and the scheme with heat and mass counterflows used in contour heat pipes. 12 refs., 4 figs., 1 tab.

Hysteresis dependences on temperature were identified in the course of investigating permeability coefficients of nickel fine-porous structure during flow of distilled water, saturated with air, through it. Study results and discussion of these dependences, influence of filter porosity as well as pressure differential on them are presented. The obt...

The results of experimental study of the influence of adsorption layers on the electric conductivity of dispersed systems are presented. The investigations are carried out using electrolytic nickel powders with different average dimensions of particles. The technique of the experiment consists in linear heating a sample at constant vacuum pumping o...

We present the results of an experimental investigation of the effects of adsorbed layers on the conductivity of a charge of finely divided nickel particles.

The authors present results of an experimental investigation of the structural, stress, trasnport and thermophysical properties of high-porosity cellular materials as applied to the capillary structures of heat pipes.

Conductivity in a granular bed has been examined in experiments on the effective thermal conductivity of a lightly pressed layer of nickel spheres less than a micron in diameter. This data was compared to a heat transfer model developed to describe this process. The model accounts for heat transfer through the granular material by conduction and ot...

The authors present results of an experimental investigation of the influence of accelerations directed along the heat-transfer vector on the operation of heat pipes with separate channels for vapor and liquid.

A set of criterial conditions is obtained for selecting the proper heat-transfer agent for low-temperature antigravity heat pipes. The criteria presented here make it possible to select a heat transfer agent with allowance for specific design constraints and operating conditions. The criteria are verified experimentally for two low-temperature anti...

The design of a limited rate heat pipe with individual channels for vapor and liquid is discussed.

The heat transfer capacity and operating conditions of an antigravity heat pipe, with separate ducts for vapor and liquid, operating in evaporation regime, are calculated. The initial data for the calculation are the height of the heat pipe, geometric dimensions, characteristics of the capillary-porous structure of the pipe, and the temperature of...

Two types of heat pipe with low-pressure injectors are considered. The pipes are intended for operation on any orientation in the gravitational field.

A number of constructional details and results are given for investigations of water and acetone heat pipes.

The water and acetone heat pipes studied are of a design where the capillary wick structure is located in the evaporating chamber and the steam and liquid channels are isolated from each other. Pipes of this type, characterized by very low hydraulic resistance, can operate at any orientation of the gravitational field. Several evaporating chamber d...

The design of a heat pipe with separate channels for vapor and liquid, ensuring high heat flux densities for any orientation in the gravitational field, is discussed.

The paper discusses the design of a long heat pipe with separate vapor and liquid ducts to provide a high-density heat flux for any orientation in a gravitational field. The heat pipe described is characterized by an absence of wick in the transfer section and a presence of finely porous filler in the evaporator and the condenser. It is shown that...

MINIATURE LOOP HEAT PIPES FOR CPU COOLING V.M. Kiseev, A.S. Nepomnyeshy, N.L. Gruzdova Ural State University Department of Thermophysics and Surface Phenomena Lenin av. 51, 620083, Ekaterinburg, Russia (3432) 616-775 (3432) 616-778 fax Valery.Kiseev@usu.ru ABSTRACT Extensive development Loop Heat Pipes (LHP) technology offers capabilities to p...