S 71 Some results of loop heat pipes development, tests and application in engineering [Text] / Yu. F. Maydanik, Y. G. Fershtater, S. V. Vershinin, V. G. Pastukhov, K. Goncharov // Proceedings of 5th International Heat Pipe Symposium (Melbourne, Australia, Nov. 17-20, 1996). - 1996. - P406-412 Рубрики: ФИЗИКА Кл.слова (ненормированные): ТРУБА КОНТУРНАЯ -- КОНТУРНАЯ ТРУБА -- ТРУБА ТЕПЛОВАЯ -- ТЕПЛОВАЯ ТРУБА |
L 88 Loop heat pipes and evaporators with advanced characteristics [Text] / Yu. F. Maydanik, S. V. Vershinin, V. G. Pastukhov, D. Gluck, C. Gerhard // Proceedings of the CPL-98 International Workshop on Capillary Pumped Two-Phase Loops (Los Angeles, USA, March 2-3, 1998). - P2. 4-1-2. 4-11 Рубрики: ФИЗИКА Кл.слова (ненормированные): ТРУБА КОНТУРНАЯ -- КОНТУРНАЯ ТРУБА -- ТРУБА ТЕПЛОВАЯ -- ТЕПЛОВАЯ ТРУБА -- ИСПАРИТЕЛИ |
M 73 Miniature loop heat pipes for electronics cooling / V. G. Pastukhov, Yu. F. Maydanik, S. V. Vershinin, M. A. Korukov // Applied Thermal Engineering : 12th International Heat Pipe Conference Location, Russia, 19-24 may 2002 . - 2003. - Vol.23, № 9. - С. 1125-1135 Рубрики: ФИЗИКА Кл.слова (ненормированные): MINIATURE LOOP HEAT PIPE -- CPU -- THERMAL RESISTANCE Аннотация: The paper is devoted to the development of miniature loop heat pipes (mLHPs) with a nominal capacity of 25-30 W and a heat-transfer distance up to 250 mm intended for cooling electronics components and CPU of mobile PC. It gives the results of investigating several prototypes of mLHPs incorporated into remote heat exchanger (RHE) systems in different conditions. It has been established that in the nominal range of heat loads orientation does not practically affect the mLHPs operating characteristics. Under air cooling the total thermal resistance of such a system is 1.7-4.0degreesC/W and depends strongly on the cooling conditions and the radiator efficiency. In this case the mLHP's own thermal resistance is in the limits from 0.3 to 1.2degreesC/W, and the maximum capacity reaches 80-120 BT. The obtained results make it possible to regard mLHPs as quite promising devices for RHE systems providing thermal regimes for electronics components and personal computers. (C) 2003 Elsevier Science Ltd. All rights reserved |
H 65 High heat flux loop heat pipes / M. T. North, D. B. Sarraf, J. H. Rosenfeld, Yu. F. Maydanik, S. V. Vershinin // 6th European Symposium on Space Environmental Control Systems: Noordwijk, Netherlands, 20-22 may 1997 . - 1997. - Vol. 400. - С. 371-376 Рубрики: ФИЗИКА Кл.слова (ненормированные): LOOP HEAT PIPES -- POWER LOADS -- GRAVITATIONAL HEADS Аннотация: Loop Heat Pipes (LHPs) can transport very large thermal power loads, over long distances, through flexible, small diameter tubes and gravitational heads. While recent transported as much as 1500 W, the peak heat flux through a LHP's evaporator has been limited to about 0.07 MW/m(2). This limitation is due to the arrangement of vapor passages next to the heat load which is one of the conditions necessary to ensure self priming of the device. This paper describes work aimed at raising this limit by threefold to tenfold. Two approaches were pursued. One optimized the vapor passage geometry for the high heat flux conditions. The geometry improved the heat flow into the wick and working fluid. This approach also employed a finer pored wick to support higher vapor flow losses. The second approach used a bidisperse wick material within the circumferential vapor passages. The bidisperse material increased the thermal conductivity and the evaporative surface area in the region of highest heat flux, while providing a flow path for the vapor. Proof-of-concept devices were fabricated and tested for each approach. Both devices operated as designed and both demonstrated operation at a heat flux of 0.70 MW/m(2) This performance exceeded the known state of the art by a factor of more than six for both conventional heat pipes and for loop heat pipes using ammonia. In addition, the bidisperse-wick device demonstrated boiling heat transfer coefficients up to 100,000 W/m(2).K, and the fine pored device demonstrated an orientation independence with its performance essentially unaffected by whether its evaporator was positioned above, below or level with the condenser |
T 44 The proof-of-feasibility of multiple evaporator loop heat pipes / W. B. Bienert, D. A. Wolf, M. N. Nikitkin, Yu. F. Maydanik, Y. G. Fershtater, S. V. Vershinin, J. M. Gottschlich // 6th European Symposium on Space Environmental Control Systems: Noordwijk, Netherlands, 20-22 may 1997 . - 1997. - Vol.400. - С. 393-398 Рубрики: ФИЗИКА Кл.слова (ненормированные): LOOP HEAT PIPES -- THERMAL CONTROL -- MULTIPLE THERMAL INTERFACE Аннотация: This paper presents results that demonstrate the proof-of-feasibility of multiple evaporator Loop Heat Pipes (LHP). It was demonstrated that a multiple evaporator LHP can successfully operate as a thermal control system component. A breadboard LHP with multiple evaporators (two) that retained the reliable self starting behavior of the single thermal interface LHP was developed. Program efforts were concentrated on a two pump system and investigated the performance of the dual evaporator LHP. Analytical predictons and experimental test data are compared, and important issues are discussed that will be a baseline for continued development of multiple thermal interface LHPs. All of the conclusions are based on test results, analytic modeling and the correlation of the two. Although a mathematical model that predicts the multiple evaporator LHP behavior was developed, the primary focus of the program was the development, fabrication, and test of a breadboard multi-evaporator LHP. The program clearly demonstrated that multi-evaporator LHPs are feasible and merit further development as a viable thermal control components |
H 65 High heat flux loop heat pipes / M. T. North, D. B. Sarraf, J. H. Rosenfeld, Yu. F. Maydanik, S. V. Vershinin // SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-97), PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION, ALBUQUERQUE, 26-30 JAN, 1997 . - 1997. - Vol.387. - С. 561-566 Рубрики: ФИЗИКА Кл.слова (ненормированные): LOOP HEAT PIPES -- THERMAL POWER LOADS -- VAPOR FLOW LOSSES Аннотация: Loop Heat Pipes (LHPs) can transport very large thermal power loads, over long distances, through flexible, small diameter tubes and against high gravitational heads. While recent LHPs have transported as much as 1500 W, the peak heat flux through a LHP's evaporator has been limited to about 0.07 MW/m(2). This limitation is due to the arrangement of vapor passages next to the heat load which is one of the conditions necessary to ensure self priming of the device. This paper describes work aimed at raising this limit by threefold to tenfold. Two approaches were pursued. One optimized the vapor passage geometry for the high heat flux conditions. The geometry improved the heat flow into the wick and working fluid. This approach also employed a finer pored wick to support higher vapor flow losses. The second approach used a bidisperse wick material within the circumferential vapor passages. The bidisperse material increased the thermal conductivity and the evaporative surface area in the region of highest heat flux, while providing a flow path for the vapor. Proof-of-concept devices were fabricated and tested for each approach. Both devices operated as designed and both demonstrated operation at a heat flux of 0.70 MW/m(2). This performance exceeded the known state of the art by a factor of more than six for both conventional heat pipes and for loop heat pipes using ammonia. In addition, the bidisperse-wick device demonstrated boiling heat transfer coefficients up to 100,000 W/m(2) K, and the fine pored device demonstrated an orientation independence with its performance essentially unaffected by whether its evaporator was positioned above, below or level with the condenser |
V 50 Vershinin, S. V. Effect of the thermal contact resistance on heat-transfer during boiling from fine porous capillary structures / S. V. Vershinin, Y. G. Fershtater, Yu. F. Maydanik // High Temperature. - 1992. - Vol.30, №4. - С. 668-673 Рубрики: ФИЗИКА Кл.слова (ненормированные): HEAT TRAHSFER -- VAPOR FORMATION Аннотация: The dependence of the heat transfer rate on the geometry of vapor channels is investigated analytically and experimentally with a consideration of the thermal contact resistance during vapor formation in fine porous structures for carrying away the vapor. It is shown that the larger the contact resistance, the greater the distance between the channels must be to maximize the values of the heat-transfer coefficients |
L 88 Loop Heat Pipes for Cooling Systems of Servers / Yu. F. Maydanik, S. V. Vershinin, V. G. Pastukhov, S. Fried // IEEE Transactions on Components and Packaging Technologies. - 2010. - Vol.33, №2. - С. 416-423 Рубрики: ФИЗИКА Кл.слова (ненормированные): HEAT-TRANSFER DEVICE -- LHPs -- OPTERON CPUs Аннотация: Loop heat pipes (LHPs) are exceptionally efficient heat-transfer devices that employ a closed loop evaporation-condensation cycle that can be used to cool densely packed electronic systems that reject large quantities of heat, including computers and their central processing units (CPUs). Tests were carried out on miniature ammonia LHPs with a CPU thermal simulator using different ways of condenser cooling. The possibility of maintaining the cooled object temperatures between 40°C and 70°C with heat load changing from 100 to 320 W was demonstrated. Subsequent tests of these devices in a 1U computer with dual core advanced micro devices Opteron CPUs, dissipating between 95 and 120 W, have confirmed the advantages and heat transfer efficiency of LHP-based cooling systems used to cool CPU in 1U chassis |
S 82 Steady state operation of a copper–water LHP with a flat-oval evaporator / S. Becker, S. V. Vershinin, V. Sartre, E. Laurien, J. Bonjour, Yu. F. Maydanik // Applied Thermal Engineering. - 2011. - Vol.31, №5. - С. 686-695. - Библиогр.: с. 695 (24 ref.) Рубрики: ФИЗИКА Кл.слова (ненормированные): LOOP HEAT PIPE -- HEAT TRAHSFER -- EXPERIMENTAL STUDY Аннотация: In order to dissipate the heat generated by electronic boxes in avionic systems, a copper–water LHP with a flat-oval evaporator was fabricated and tested at steady state. The LHP consists of a flat shaped evaporator, 7 mm thick, including compensation chamber with attached heat exchanger. The condenser is cooled by forced convection of liquid. The variable parameters are the heat sink and ambient temperatures (20 and 55 °C), the orientation (−90° to +90° in two perpendicular planes) and the power input (0–100 W). Evaporator wall temperatures are higher when the evaporator is placed above the condenser. For heat sink and ambient temperature of 20 °C the evaporator wall temperature does not vary much with heat load for all measured elevations. But it fluctuates at heat sink and ambient temperature equal to 55 °C when the evaporator is placed below the condenser. The LHP total thermal resistance is governed by the condenser resistance. It decreases with increasing heat load, whatever the operating conditions, because the part of the condenser internal surface area used for condensation increases too. A minimum thermal resistance of 0.2 K/W was obtained. The maximum thermal resistance was 2.7 K/W \\\\expert2\\NBO\\Applied Thermal Engineering\\2011, v. 31, p.686.pdf |
I-70 Investigation of a compact copper–water loop heap pipe with a flat evaporator / Yu. F. Maydanik, S. V. Vershinin, M. Chernysheva, S. Yushakova // Applied Thermal Engineering. - 2011. - Vol.31, №16. - С. 3533-3541. - Библиогр.: с. 3541 (22 ref.) Рубрики: ФИЗИКА Кл.слова (ненормированные): ELECTRONICS COOLING -- LOOP HEAT PIPE -- FLAT–OVAL EVAPORATOR Аннотация: A compact copper–water loop heat pipe (LHP) with an effective length of 310 mm equipped with a flat–oval evaporator measuring 80 (L) × 42 (W) × 7 (H) has been tested. The vapor line and the condenser had the same internal diameter of 5.4 mm. The internal diameter of the liquid line was 3.4 mm. Tests were conducted with a heat source which had a heating surface of 30 mm × 30 mm. The condenser was cooled by running water with a temperature of 20 °C. In the horizontal position the device has exhibited serviceability in the heat load range from 5 W to 1200 W at vapor temperatures from 26.5 °C to 103.4 °C. The maximum capacity was achieved at a heat source temperature of 143.5 °C, when the LHP thermal resistance was equal to 0.044 °C/W. The corresponding values of thermal resistance for the evaporator and the condenser were at a level of 0.006 °C/W and 0.038 °C/W. A minimum thermal resistance of 0.097 °C/W for the “heat source–LHP–cooling water” system was obtained at a heat load of about 700 W, at which the temperature of the heat source was 87 °C \\\\expert2\\NBO\\Applied Thermal Engineering\\2011, v. 31, p.3533.pdf |
P 30 Passive cooling system for an aircraft electronic box / Yu. F. Maydanik, S. V. Vershinin, V. G. Pastukhov, M. Chernysheva, C. Sarno, C. Tantolin // Heat Pipe Science and Technology, An International Journal , vol. - 2010. - Vol.1, №3. - С. 251-260 Рубрики: ФИЗИКА Кл.слова (ненормированные): AIRCRAFTS -- LOOP HEAT PIPE -- ELECTRONIC BOX -- PASSIVE COOLING SYSTEM Аннотация: The paper represents the results of development and thermal tests of a cooling system of a seat electronic box, managing the in-flight entertainment system used aboard commercial aircrafts. The system is completely passive and consists of two conventional copper-water miniature heat pipes and two miniature loop heat pipes with R-141b as a working fluid. Two crossbeams of a passenger seat made of aluminum alloy cooled by means of free air convection were used as heat sinks. At the maximum heat load of 100 W the cooling system provides a temperature of a cooled object at a level of not above 81°C at the ambient temperature of 22°C, which is 4°C below that of the maximum specified temperature |
M 19 Maydanik, Yu. F. Development and Tests of Miniature Loop Heat Pipe with a Flat Evaporator / Yu. F. Maydanik, S. V. Vershinin, M. A. Chenysheva // SAE 2000 Transaction - Journal of Aerospace. - 2001. - Paper Number: 2000-01-2491 Рубрики: ФИЗИКА Кл.слова (ненормированные): AMMONIA MINIATURE -- LOOP HEAT PIPE -- FLAT EVAPORATOR Аннотация: The paper presents the results of analysis, development and tests of an ammonia miniature loop heat pipe (MLHP) with a flat evaporator, which has an active-zone diameter of 30mm. The length and the diameter of the vapor and the liquid lines are 1m and 2/1.2mm. The device serviceability has been demonstrated at a horizontal and a vertical orientation in 1-g conditions. The maximum heat load achieved on trials was equal, respectively, to 160W and 120W, which corresponds to a heat flow in the evaporation zone of 23 W/cm 2 and 17 W/cm 2 . The minimum thermal resistance at nominal heat loads from 40 to 80 W varied in the range from 0.42 W/m 2 K to 0.59 W/m 2 K. A comparison has been made with a model MLHP with a cylindrical evaporator equipped with a copper and aluminum “sa |
M 73 Miniature loop heat pipes-a promising means for cooling electronics / Yu. F. Maydanik, S. V. Vershinin, M. A. Korukov, J. M. Ochterbeck // IEEE Transactions on Components and Packaging Technologies. - 2005. - Vol.28, №2. - С. 290-296 Рубрики: ФИЗИКА Кл.слова (ненормированные): LOOP HEAT PIPES -- HEAT-TRANSFER DEVICE -- MINIATURE LOOP HEAT PIPE Аннотация: Loop heat pipes (LHPs) are highly efficient heat-transfer devices, which have considerable advantages over conventional heat pipes. Currently, miniature LHPs (MLHPs) with masses ranging from 10-20 g and ammonia and water as working fluids have been developed and tested. The MLHPs are capable of transferring heat loads of 100-200 W for distances up to 300 mm in the temperature range 50-100°C at any orientation in 1-g conditions. The thermal resistance for these conditions are in the range from 0.1 to 0.2 K/W. The devices possess mechanical flexibility and are adaptable to different conditions of location and operation. Such characteristics of MLHPs open numerous prospects for use in cooling systems of electronics and computer systems |
V 50 Vershinin, S. V. Hysteresis phenomena in loop heat pipes / S. V. Vershinin, Yu. F. Maydanik // Applied Thermal Engineering. - 2007. - Vol.27, №5-6. - С. 962-968 Рубрики: ФИЗИКА Кл.слова (ненормированные): LOOP HEAT PIPE -- CAPILLARY METHOD -- EVAPORATION Аннотация: Testing of loop heat pipes (LHPs) has shown that the heat-load dependence of the operating temperature is not always unambiguous. It may have a hysteresis nature. It has been found that temperature hysteresis is connected with changes in the liquid distribution between the compensation chamber (CC) and the condenser. Analysis makes it possible to distinguish three types of temperature hysteresis. In the first case this redistribution is caused by the change in the amount of the parasitic heat flow that penetrates into the CC, which in its turn is a result of heat-transfer hysteresis in the evaporation zone. In the second, temperature hysteresis is connected with the liquid metastable state, which leads to a delay of formation of the vapor phase in the compensation chamber. The reason for hysteresis of the third type is the change of the initial liquid distribution in an LHP during a start-up |
V 50 Vershinin, S. V. Investigation of pulsations of the operating temperature in a miniature loop heat pipe / S. V. Vershinin, Yu. F. Maydanik // International Journal of Heat and Mass Transfer. - 2007. - Vol.50, №25-26. - С. 5232-5240 Рубрики: ФИЗИКА Кл.слова (ненормированные): LOOP HEAT PIPE -- PULSATION HEAT -- HIGH-TEMPERATURE SUPERCONDUCTOR |
M 43 Maydanik, Yu. F. Development and tests of ammonia Miniature Loop Heat Pipes with cylindrical evaporators / Yu. F. Maydanik, S. V. Vershinin // Applied Thermal Engineering. - 2009. - Vol.29, №11-12. - С. 2297-2301 Рубрики: ФИЗИКА Кл.слова (ненормированные): LOOP HEAT PIPE -- EVAPORATOR -- CONDENSER Аннотация: Miniature Loop Heat Pipes (MLHPs) are an attractive object for development and investigation as quite a promising means for cooling powerful electronics operating in the temperature range from 50 to 100 °C. The paper generalizes and presents the results of development and tests of 15 different variants of ammonia MLHPs with cylindrical evaporators 5 and 6 mm in diameter, which have an active zone length of 20 mm and are equipped with titanium and nickel wicks. As a result of successive efforts aimed at increasing the MLHPs efficiency, it was possible to achieve values of the heat-transfer coefficient close to 162,000 W/m2 °C at a value of the heat flux of about 100 × 104 W/m2. A maximum heat flux value of about 135 × 104 W/m2 was achieved at the heat-transfer coefficient equal approximately to 75,000 W/m2 °C |
C 51 Chernysheva, M. A. Heat transfer during condensation of moving steam in a narrow channel / M. A. Chernysheva, S. V. Vershinin, Yu. F. Maydanik // International Journal of Heat and Mass Transfer. - 2009. - Vol.52, №11-12. - С. 2437-2443 Рубрики: ФИЗИКА Кл.слова (ненормированные): INTUBE CONDENSATION -- TWO-PHASE FLOW -- LOOP HEAT PIPE Аннотация: The paper presents the results of experimental investigation of heat transfer and hydrodynamics during condensation of moving steam in a narrow channel of square cross-section 2 mm × 2 mm. The channel had a serpentine shape, the channel length was 660 mm. An experimental cell simulated conditions of heat transfer in the condenser of loop heat pipes. The steam velocity at the channel inlet ranged from 13 to 52 m/s, the pressure was 1 atm. The temperature of the cooling water varied from 70 to 95 °C. The annular flow pattern was noted in the whole range of the regime parameters. There was a clear boundary between the condensation zone and the zone occupied by the condensed phase downstream. Temperature has measured along the channel, and the heat-transfer coefficients have been determined. The coefficient values varied from 10,000 to 55,000 W/K m2 depending on the steam velocity at the channel inlet and the cooling temperature. The efficiency of the condenser – heat exchanger has been investigated |
B 27 Bartuli, E. Visual and instrumental investigations of a copper-water loop heat pipe [Электронный ресурс] / E. Bartuli, S. V. Vershinin, Yu. F. Maydanik // International Journal of Heat and Mass Transfer. - 2013. - Vol.61, №1. - P35-40 Рубрики: ФИЗИКА Кл.слова (ненормированные): CONDENSATION -- COPPER-WATER LOOP HEAT PIPE -- FLAT GAP CONDENSER Аннотация: Visual and instrumental investigations of the processes of condensation and redistribution of a working fluid in a loop heat pipe have been carried out. This paper presents the results of an experimental investigation of the heat transfer and hydrodynamics during the condensation of water vapor in a flat gap condenser measuring 80 × 40 × 1 mm. Investigations have been conducted at a condenser cooling temperature of 20, 40 and 60 °. During all operating modes a stratified two-phase flow and film condensation have been observed. The temperature field in the condenser has been measured, and the heat-transfer coefficients and the thermal resistances have been determined |
L 88 Loop thermosyphon thermal management of the avionics of an in-flight entertainment system [Электронный ресурс] / C. Sarno, C. Tantolin, R. Hodot, Yu. F. Maydanik, S. V. Vershinin // Applied Thermal Engineering. - 2013. - Vol.51, №1-2. - P764-769 Рубрики: ФИЗИКА Кл.слова (ненормированные): AVIONICS -- COOLING SYSTEM -- LOOP THERMOSYPHON Аннотация: A new generation of in-flight entertainment systems (IFEs) used on board commercial aircrafts is required to provide more and more services (audio, video, internet, multimedia, phone, etc.). But, unlike other avionics systems most of the IFE equipment and boxes are installed inside the cabin and they are not connected to the aircraft cooling system. The most critical equipment of the IFE system is a seat electronic box (SEB) installed under each passenger seat. Fans are necessary to face the increasing power dissipation. But this traditional approach has some drawbacks: extra cost multiplied by the seat number, reliability and maintenance. The objective of this work is to develop and evaluate an alternative completely passive cooling system (PCS) based on a two-phase technology including heat pipes and loop thermosyphons (LTSs) adequately integrated inside the seat structure and using the benefit of the seat frame as a heat sink. Previous works have been performed to evaluate these passive cooling systems which were based on loop heat pipe. This paper presents results of thermal tests of a passive cooling system of the SEB consisting of two LTSs and R141b as a working fluid. These tests have been carried out at different tilt angles and heat loads from 10 to 100 W. It has been shown that the cooled object temperature does not exceed the maximum given value in the range of tilt angles ±20° which is more wider than the range which is typical for ordinary evolution of passenger aircrafts |
S 71 Some results of loop heat pipes development, tests and application in engineering [Text] / Yu. F. Maydanik, Y. G. Fershtater, S. V. Vershinin, V. G. Pastukhov, K. Goncharov // Proceedings of 5th International Heat Pipe Symposium (Melbourne, Australia, Nov. 17-20, 1996). - 1996. - P406-412 Рубрики: ФИЗИКА Кл.слова (ненормированные): ТРУБА КОНТУРНАЯ -- КОНТУРНАЯ ТРУБА -- ТРУБА ТЕПЛОВАЯ -- ТЕПЛОВАЯ ТРУБА |