Additives to Increase Fuel Heat Sink Capacity in a Fuel/Air Heat Exchanger

2005 ◽  
Author(s):  
David Wickham ◽  
Jeffrey Engel ◽  
Sean Rooney ◽  
Bradley Hitch
Keyword(s):  
Heat Exchanger ◽  
Heat Sink ◽  
Sink Capacity

scholarly journals Catalytic Cracking and Heat Sink Capacity of Aviation Kerosene Under Supercritical Conditions

2009 ◽  
Vol 25 (6) ◽  
pp. 1226-1232 ◽  
Author(s):  
X. J. Fan ◽  
F. Q. Zhong ◽  
G. Yu ◽  
J. G. Li ◽  
C. J. Sung
Keyword(s):  
Heat Sink ◽  
Catalytic Cracking ◽  
Supercritical Conditions ◽  
Aviation Kerosene ◽  
Sink Capacity

Analysis of Heat Transfer Enhancement in Minichannel Heat Sinks With Turbulent Flow Using H2O–Al2O3 Nanofluids

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
T. L. Bergman
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Turbulent Flow ◽  
Heat Transfer Enhancement ◽  
Thermophysical Properties ◽  
Heat Sink ◽  
Heat Sinks ◽  
Transfer Enhancement ◽  
Electronic Heat ◽  
Limited Usefulness

Heat transfer enhancement associated with use of a nanofluid coolant is analyzed for small electronic heat sinks. The analysis is based on the ε-NTU heat exchanger methodology, and is used to examine enhancement associated with use of H2O–Al2O3 nanofluids in a heat sink experiencing turbulent flow. Predictive correlations are generated to ascertain the degree of enhancement based on the fluid’s thermophysical properties. The enhancement is quite small, suggesting the limited usefulness of nanofluids in this particular application.

scholarly journals Thermal Cracking and Heat Sink Capacity of Aviation Kerosene Under Supercritical Conditions

2011 ◽  
Vol 25 (3) ◽  
pp. 450-456 ◽  
Author(s):  
Fengquan Zhong ◽  
Xuejun Fan ◽  
Gong Yu ◽  
Jianguo Li ◽  
Chih-Jen Sung
Keyword(s):  
Heat Sink ◽  
Thermal Cracking ◽  
Supercritical Conditions ◽  
Aviation Kerosene ◽  
Sink Capacity

THERMAL CONTROL OF THERMOELECTRIC COOLING DEVICES OF TRANSMISSION AND RECEIVING ELEMENTS OF ON-BOARD INFORMATION SYSTEMS

2020 ◽  
Vol 3 (4) ◽  
pp. 263-278
Author(s):  
Vladimir Ivanovich Mescheryakov ◽  
Vladimir Petrovich Zaykov ◽  
Yurii Ivanovich Zhuravlov
Keyword(s):  
Dynamic Model ◽  
Dynamic Characteristics ◽  
Heat Sink ◽  
Operating Mode ◽  
Stationary Mode ◽  
Thermoelectric Cooler ◽  
Operating Modes ◽  
Reliability Indicators ◽  
Sink Capacity ◽  
Current Operating

The work is a continuation of studies of the dynamic characteristics of thermoelectric coolers aimed at analyzing the influence of temperature differences, current operating modes, design parameters of the device and physical parameters of the material of thermoelements for a time constant. The article analyzes the effect of the heat sink capacity of the radiator on the dynamic characteristics, energy and reliability indicators of a single-stage thermoelectric cooler. A dynamic model of a thermoelectric cooler has been developed taking into account the weight and size parameters of the radiator, which relate the main energy indicators of the cooler with the heat removal capacity of the radiator, operating currents, the value of the heat load and the relative temperature difference. The analysis of the dynamic model shows that with an increase in the heat-removing capacity of the radiator at a given thermal load and various current modes, the main parameters of the cooler change. The required number of thermoelements, power consumption, time to reach a stationary mode, and relative failure rate are reduced. With an increase in the relative operating current, the time to reach the stationary mode of operation decreases for different values of the heat sink capacity of the radiator. It is shown that the minimum time to reach the stationary operating mode is provided in the maximum refrigerating capacity mode. The studies were carried out at different values of the heat sink capacity of the radiator in the operating range of temperature drops and the geometry of thermoelements. The possibility of minimizing the heat-dissipating surface of the radiator at various current operating modes and the relationship with the main parameters, reliability indicators and the time to reach the stationary operating mode are shown. Comparative analysis of weight and size characteristics, main parameters, reliability indicators and dynamics of functioning with rational design makes it possible to choose compromise solutions, taking into account the weight of each of the limiting factors.

iB1350: Innovative Passive Containment Cooling System for the iB1350

2016 ◽  
Author(s):  
Takashi Sato ◽  
Keiji Matsumoto ◽  
Nobuhiro Hara
Keyword(s):  
Heat Exchanger ◽  
Heat Sink ◽  
Cooling System ◽  
Differential Pressure ◽  
Severe Accident ◽  
The Core ◽  
Noncondensable Gases ◽  
Suction Pipe ◽  
Conventional Design

iB1350 stands for an innovative, intelligent and inexpensive BWR 1350. The iB1350 uses innovative passive containment cooling system (iPCCS). The iPCCS is a part of the in-containment filtered venting system (IFVS). The vent pipe is submerged in the IFVS tank in the outer well (OW) of the Mark W containment. The conventional PCCS has a suction pipe only from the dry well (DW). On the contrary, the iPCCS has two suction pipes. One is normally opened to the wet well (WW) and another normally closed to the DW. The suction pipe in the conventional design cannot be connected to the WW because the PCCS vent pipe is connected to the WW. A PCCS functions using differential pressure between two nodes to discharge noncondensable gases in a PCCS heat exchanger (Hx). A suction pipe and a vent pipe must be connected to different nodes to use differential pressure. Therefore, the conventional PCCS never can cool the S/P. Although the S/P is the in-containment heat sink, heat up of the S/P is the most unfavorable for the conventional PCCS. In order to use the PCCS the conventional design must discharge steam directly into the DW instead of the S/P. Therefore, the conventional PCCS must open depressurization valves (DPV) at a SBO if the isolation condenser (IC) fails. On the contrary, the iPCCS can cool the S/P directly using the suction pipe connected to the WW and without DPV. Instead of DPV the iB1350 has modulating valves (MV) of which discharge lines are submerged in the S/P. Even if the IC fails during a SBO, the iB1350 can cool the core using the severe accident feedwater system (SAFWS), the SRV or the MV, and the iPCCS. The SAFWS makes up the core. The decay heat is carried by steam to the S/P through the SRV or the MV. The S/P works as in-containment heat sink. Once the S/P starts boiling the iPCCS automatically initiates cooling of the steam from the S/P. In the case of a core melt accident, a certain amount of FP is released into the S/P and heats up the S/P. Once the S/P starts boiling, the noncondensable gases in the WW is purged by the steam into the DW and then into the PCCS Hx. In order to purge the stagnant gases, the conventional PCCS needs an active fan in the long term. On the contrary, the iPCCS can easily purge noncondensable gases in the heat exchanger using differential pressure to the OW and need not any active fan even in the long term.

scholarly journals Rapid Prototyping of Polymer-Based Rolled-Up Microfluidic Devices

Micromachines ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 516 ◽  
Author(s):  
Rerngchai Arayanarakool ◽  
Hian See ◽  
Samuel Marshall ◽  
Niven Virik ◽  
Heng Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thin Films ◽  
Heat Exchanger ◽  
Heat Sink ◽  
Three Dimensional ◽  
Microfluidic System ◽  
Curved Channels ◽  
Polymeric Thin Film ◽  
Rapid Fabrication ◽  
Spiral Microchannel

This work presents the simple and rapid fabrication of a polymer-based microfluidic prototype manufactured by rolling up thin films of polymer. The thin films were fabricated via a casting method and rolled up around a center core with the aid of plasma activation to create a three-dimensional (3D) spiral microchannel, hence reducing the time and cost of manufacture. In this work, rolled-up devices with single or dual fluidic networks fabricated from a single or two films were demonstrated for heat sink or heat exchanger applications, respectively. The experimental results show good heat transfer in the rolled-up system at various flow rates for both heat sink and heat exchanger devices, without any leakages. The rolled-up microfluidic system creates multiple curved channels, allowing for the generation of Dean vortices, which in turn lead to an enhancement of heat and mass transfer and prevention of fouling formation. These benefits enable the devices to be employed for many diverse applications, such as heat-transfer devices, micromixers, and sorters. To our knowledge, this work would be the first report on a microfluidic prototype of 3D spiral microchannel made from rolled-up polymeric thin film. This novel fabrication approach may represent the first step towards the development of a pioneering prototype for roll-to-roll processing, permitting the mass production of polymer-based microchannels from single or multiple thin films.

Performance Characteristics of 20kW Ocean Thermal Energy Conversion Pilot Plant

2015 ◽  
Author(s):  
Ho-Saeng Lee ◽  
Seung-Won Lee ◽  
Hyeon-Ju Kim ◽  
Young-Kwon Jung
Keyword(s):  
Heat Exchanger ◽  
Heat Source ◽  
Energy Conversion ◽  
Thermal Energy ◽  
Temperature Difference ◽  
Heat Sink ◽  
Pilot Plant ◽  
Working Fluid ◽  
Thermal Energy Conversion ◽  
Ocean Thermal Energy

To experiment 20kW OTEC, the closed-cycle type of OTEC (Ocean Thermal Energy Conversion) was designed and manufactured. R32 (Difluoromethane, CH2F2) was used as the working fluid and a temperature of heat source and heat sink is 26°C, 5°C, respectively. The semi-welded type heat exchanger is applied for the evaporator and condenser and the cycle was designed for the gross power of 20kW. In the plate arrangement of the semi-welded type heat exchanger, one channel for working fluid is welded, and another channel for seawater is sealed by gasket. In this paper, various performance evaluations and experiments were carried out as constructing subminiature pilot plant of the OTEC and compared with the results of cycle analysis. In results, gross power of the turbine shows 20.1kW and cycle efficiency is 1.91% when heat source and heat sink is 26°C, 5°C. For the variation of temperature difference between the heat source and heat sink, when the temperature difference was 21°C, the gross power increased by about 33.3% from that when the temperature difference was 19 °C.

Coefficient of Performance of Thermoelectric Cooling on Nanofluids

2013 ◽  
Vol 459 ◽  
pp. 91-99
Author(s):  
Somchai Maneewan ◽  
Atthakorn Thongtha ◽  
Chantana Punlek
Keyword(s):  
Heat Exchanger ◽  
Ethylene Glycol ◽  
Heat Sink ◽  
Cooling System ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Cold Side ◽  
Input Condition ◽  
Current Input ◽  
Experimental Comparisons

This paper reports on experimental comparisons of coefficient of performance (COP) of a thermoelectric coolingsystem which cooled the hot side of the TEC by water (wc), ethylene glycol (egc) and nanofluids (nfc) The nanofluids is composed of ethylene glycol with silver nano(35 nm).The TEC was composed of the TE cooling modules, heat exchanger, and the air cooled heat sink at the cold side of the TE modules.Experiments were conducted with various current input 1 - 4.5 A to find out the optimum current input condition. To consideration of cooling capacity and COP of system was measured the hot and cold side temperature of TEC. Results shown that, the cooling capacity was increased with current input. The maximum cooling capacity of nfc, egc and wc are about 72, 62 and 41 W, respectively. Considered with highest COP found that the optimum current input is approximately 2.5 A. The maximum COP of nfc, egc and wc are about 2.01, 1.7 and 1.12, respectively. Therefore, the proposed TEC-nfc concept is expected to contribute to wider applications of the TE cooling system.

Evaluation of Heat Transfer Performance of a Spiral Microfluidic Heatsink and Heat Exchanger Device

2018 ◽  
Author(s):  
Niven Singh Virik ◽  
Samuel D. Marshall ◽  
Rerngchai Arayanarakool ◽  
Hian Hian See ◽  
Heng Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Thermal Performance ◽  
Heat Sink ◽  
High Efficiency ◽  
Microfluidic Channel ◽  
Microfluidic Devices ◽  
Flow Rates ◽  
Dean Vortices ◽  
Number Of Layers

Developments in micro-technology have seen vast improvements in the design and the thermal performance of heat sinks and heat exchangers, particularly in the case of spiral microfluidic devices which deals with the flow of liquids inside curved micrometer-sized channels. The current research deals with a specially designed curved microfluidic channel used to employ the fluid mixing characteristics of Dean vortices and thus transfer heat more efficiently. This curved microfluidic channel is deployed as a spiral channel to create an effective heat sink and a heat exchanger. The novel micro heat exchanger is built by integrating two or more of the specially designed microfluidic heat sink layers. For the ease of fabricating the microchannels, these devices are polymer-based. In this paper, the thermal performance of the spiral microfluidic devices is analyzed numerically and experimentally using a range of flow rates where Thermal Performance Factor is used to find a balanced point between heat transfer and pressure drop. The spiral heat exchange device proves to be an effective thermal transport system with the introduction of curved channels in the devices where the presence of Dean vortices in the system is observed, especially at lower flow rates. It can be observed that by increasing the number of layers, the thermal performance is greatly improved. This is due to the higher surface area with increasing number of layers, as well as a parallel flow structure through the layers. These results serve as a design parameter for developing microchannel-based heat transfer devices that can achieve high efficiency of heat and mass transfer. Further heat sink and heat exchanger design improvements are discussed.

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