Development of a Gravity-Assist Water Loop Heat Pipe With Flat Evaporator for Waste Heat Removal

2003 ◽  
Author(s):  
Triem T. Hoang ◽  
Tamara A. O’Connell ◽  
C. Thomas Conroy ◽  
Robert G. Mahorter ◽  
John A. Savchik ◽  
...  
Keyword(s):  
Heat Transport ◽  
Waste Heat ◽  
Fluid Management ◽  
Heat Removal ◽  
Heat Pipes ◽  
Pressure Head ◽  
Thermal Control ◽  
Transport Systems ◽  
Gravity Assist ◽  
Long Distance

Use of capillary pumped heat transport devices such as heat pipes, Capillary Pumped Loops (CPLs), and Loop Heat Pipes (LHPs) are being considered for cooling of shipboard electronics. These capillary devices contain no mechanical moving parts to wear out, require no electrical power to operate, and demand virtually no maintenance. Heat pipes have been the mainstay of spacecraft thermal control systems over the past 30 years. However with limited pumping heads, heat pipes were utilized only in a few terrestrial applications. Successful demonstration of much higher pumping capability of CPLs and LHPs in recent years now makes them feasible for ground-based heat transport systems. Fluid management in a gravity environment is also much easier that the traditional design of a CPL/LHP does not really apply to terrestrial systems. In addition, a gravitational pressure head generated by a vertical distance between the condenser and evaporator can assist the capillary pumping to augment the overall pumping capability of the loop. Thus, when properly designed, a gravity-assist CPL/LHP can transport a large amount of waste heat over a long distance for dissipation.

A High Performance Semi-Passive Cooling System: The Pulse Thermal Loop

Volume 3 ◽  
2004 ◽  
Author(s):  
Mark M. Weislogel ◽  
Michael A. Bacich
Keyword(s):  
Heat Transport ◽  
High Performance ◽  
Driving Forces ◽  
Cooling System ◽  
Heat Pipes ◽  
Thermal Control ◽  
High Heat ◽  
Transport Systems ◽  
Passive Cooling ◽  
Cooling Systems

Over the past decade, the search for and development of high performance thermal transport systems for a variety of cooling and thermal control applications have intensified. One approach employs a new semi-passive oscillatory heat transport system called the Pulse Thermal Loop (PTL). The PTL, which has only recently begun to be characterized, exploits large pressure differentials from coupled evaporators to force (pulse) fluid through the system. Driving pressures of over 1.8MPa (260psid) have been demonstrated. Other passive cooling systems, such as heat pipes and Loop Heat Pipes, are limited by capillary driving forces, typically less than 70kPa (10psid). Large driving forces can be achieved by a mechanically pumped loop, however, at the expense of increased power consumption, increased total mass, and increased system cost and complexity. The PTL can be configured in either active or semi-passive modes, it can be readily designed for large ∼ O(100kW) or small ∼ O(10W) heat loads, and it has a variety of unique performance characteristics. For low surface tension dielectric fluids such as R-134a, the PTL system has over a 10-fold heat carrying capacity in comparison to high performance heat pipes. Data accumulated thus far demonstrate that the PTL can meet many of the requirements of advanced terrestrial and spacecraft cooling systems: a system that is robust, ‘semi-passive,’ high flux, and offers high heat transport thermal control while remaining flexible in design, potentially lightweight, and cost competitive.

scholarly journals Effect of Coolant Inventories and Parallel Loop Interconnections on the Natural Circulation in Various Heat Transport Systems of a Nuclear Power Plant during Station Blackout

2008 ◽  
Vol 2008 ◽  
pp. 1-11 ◽  
Author(s):  
Avinash J. Gaikwad ◽  
P. K. Vijayan ◽  
Sharad Bhartya ◽  
Kannan Iyer ◽  
Rajesh Kumar ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Heat Transport ◽  
Nuclear Power ◽  
Natural Circulation ◽  
Heat Removal ◽  
Transport Systems ◽  
Critical Examination ◽  
Decay Heat ◽  
Station Blackout

Provision of passive means to reactor core decay heat removal enhances the nuclear power plant (NPP) safety and availability. In the earlier Indian pressurised heavy water reactors (IPHWRs), like the 220 MWe and the 540 MWe, crash cooldown from the steam generators (SGs) is resorted to mitigate consequences of station blackout (SBO). In the 700 MWe PHWR currently being designed an additional passive decay heat removal (PDHR) system is also incorporated to condense the steam generated in the boilers during a SBO. The sustainability of natural circulation in the various heat transport systems (i.e., primary heat transport (PHT), SGs, and PDHRs) under station blackout depends on the corresponding system's coolant inventories and the coolant circuit configurations (i.e., parallel paths and interconnections). On the primary side, the interconnection between the two primary loops plays an important role to sustain the natural circulation heat removal. On the secondary side, the steam lines interconnections and the initial inventory in the SGs prior to cooldown, that is, hooking up of the PDHRs are very important. This paper attempts to open up discussions on the concept and the core issues associated with passive systems which can provide continued heat sink during such accident scenarios. The discussions would include the criteria for design, and performance of such concepts already implemented and proposes schemes to be implemented in the proposed 700 MWe IPHWR. The designer feedbacks generated, and critical examination of performance analysis results for the added passive system to the existing generation II & III reactors will help ascertaining that these safety systems/inventories in fact perform in sustaining decay heat removal and augmenting safety.

Harvesting Waste Heat Energy from Automobile Engine Exhaust Using Teg with Heat Pipes

2018 ◽  
Vol 7 (4.35) ◽  
pp. 85
Author(s):  
Arun Seeralan Balakrishnan ◽  
Farrukh Nagi ◽  
Khairul Salleh ◽  
Prem A/L Gunnasegaran
Keyword(s):  
Finite Element ◽  
Waste Heat ◽  
Heat Removal ◽  
Heat Pipes ◽  
Heat Energy ◽  
Exhaust Pipe ◽  
Cold Side ◽  
Exhaust Heat ◽  
Pipe Line ◽  
Nano Fluids

This research investigates how the heat from car exhaust pipe line can be recovered as power using passive Thermo electric generator (TEG) using heat pipes. In this research the heat pipes are place on the cold side of TEG to remove the rising temperature and hot side of TEG is placed on the circumference of exhaust pipe line of car engine. The heat pipes with and without nano-fluids were placed on cold side of TEGs to investigate heat removal from increasing temperature and too maintain constant temperature on cold side. On the basis of results from 3D finite element simulations and experiments in the setup, the heat flow, voltage, and current were measured. The method presented in this paper gives detailed insight into how TEG modules perform in general, and also enables prediction of potential improvement in module performance by using different nano-fluids as coolants and Preliminary results were obtained. The results of Finite Element Analysis are analogous with the experimental results of TEG with water filled heat pipes with minimal possible errors. Therefore, the performance of nano-fluids in heat pipes are numerically evaluated and proposal are made for the enhancement of Module power outputs in Harnessing exhaust heat energy.

scholarly journals Effect of heat pipe failure on performance of residual heatremoval system with heat pipe for small lead-based reactor

2021 ◽  
Vol 248 ◽  
pp. 01021
Author(s):  
Chongju Hu ◽  
Hongyan Wang ◽  
Bo Wu ◽  
Xiuxiang Zhang ◽  
Pinghua Zhang
Keyword(s):  
Heat Pipe ◽  
Waste Heat ◽  
Heat Removal ◽  
Heat Pipes ◽  
Normal Operation ◽  
Pipe Failure ◽  
The Core ◽  
External Power ◽  
Heat Removal System ◽  
Removal System

Heat pipe have the characteristics of high thermal conductivity, high safety performance, without external power, etc. In this paper, The numerical simulation CFD software FLUENT is used to study the thermal-hydraulic characteristics performance of heat pipe waste heat removal system with heat pipe for lead-based reactor under normal conditions and Station-Black-Out (SBO) with partial heat pipes damage respectively. Results showed that heat pipes promote heat transfer in the reactor and reduced the temperature of the fluid around the reactor during normal operation; Heat in the core could be removed smoothly by the PRHRS during SBO accident without heat pipe damage ; and when the proportion of failed heat pipes is less than 50% during SBO accident , the PRHRS could still ensure safe operation of the reactor and the distribution of failed heat pipes in the reactor results the core temperature variation by less than 5 K.

scholarly journals Simulation of the thermal control system of nanosatellite using the loop heat pipes under the orbital flight conditions

2021 ◽  
Vol 22 (1) ◽  
pp. 23-35
Author(s):  
Yu Wang ◽  
Oleg V. Denisov ◽  
Liliana V. Denisova
Keyword(s):  
Control System ◽  
Thermal Regime ◽  
Thermal Power ◽  
Heat Removal ◽  
Heat Pipes ◽  
Thermal Control ◽  
Thermal Design ◽  
Loop Heat Pipes ◽  
Thermal Control System ◽  
Design Power

One of the key problems in the development of nanosatellites is to provide a given temperature range for the operation of the on-board computer. The constantly increasing information load leads to the need to use more advanced processors with high thermal design power (TDP). The indicated thermal regime of processors can be achieved using remote heat removal systems - miniature loop heat pipes. Using a model of nanosatellite as an example, a thermal control system with miniature loop heat pipes is designed. The simulation was carried out in the Siemens NX program in the elliptical and geostationary orbits of the Earth. The cooling schemes of the processor with a thermal power of 15 W using one and two loop heat pipes are considered. Calculations showed that the use of loop heat pipes can reduce the processor temperature to acceptable values. The anisotropy of the thermal conductivity coefficient in the reinforcement plane of the composite material of the nanosatellite case can have a significant effect on the temperature of the processor. This opens up prospects for the use of anisotropic composite materials to ensure the thermal regime of the nanosatellite.

scholarly journals Gravity-assist heat pipes for thermal control systems

1975 ◽  
Author(s):  
J.E. Deverall ◽  
E.S. Keddy ◽  
J.E. Kemme ◽  
J.R. Phillips
Keyword(s):  
Control Systems ◽  
Heat Pipes ◽  
Thermal Control ◽  
Gravity Assist

Miniature Loop Heat Pipes for Electronic Cooling

2003 ◽  
Author(s):  
Triem T. Hoang ◽  
Tamara A. O’Connell ◽  
Jentung Ku ◽  
C. Dan Butler ◽  
Theodore D. Swanson
Keyword(s):  
Heat Transport ◽  
Electrical Power ◽  
Heat Pipes ◽  
Thermal Control ◽  
Electronic Cooling ◽  
Working Fluid ◽  
Cooling Systems ◽  
Loop Heat Pipes ◽  
Steel Tubing ◽  
Operational Issues

Thermal management of modern electronics has become a problem of significant interest due to the demand for power and reduction in packaging size. Requirements of next-generation microprocessors in terms of power dissipation and heat flux will certainly outgrow the capability of today’s thermal control technology. LHPs, like conventional heat pipes, are capillary pumped heat transport devices. They contain no mechanical moving part to wear out or require electrical power to operate. But unlike heat pipes, LHPs possess much higher heat transport capabilities enabling them to transport large amounts of heat over long distances in small flexible lines for heat rejection. In fact, a miniature ammonia LHP developed for a NASA space program is capable of transporting 60W over a distance of 1 meter in 1/16”O.D. stainless steel tubing. Therefore, miniature LHPs using water as the working fluid are excellent candidates to replace heat pipes as heat transports in electronic cooling systems. However, a number of operational issues regarding system performance, cost, and integration/packaging must be resolved before water LHPs can become a viable option for commercial electronics.

Miniature Heat Pipes for Thermal Control of Radio-Electronic Equipment

2007 ◽  
Vol 38 (3) ◽  
pp. 245-258 ◽  
Author(s):  
Leonid L. Vasiliev ◽  
Andrei G. Kulakov ◽  
L. L. Vasiliev, Jr ◽  
Mikhail I. Rabetskii ◽  
A. A. Antukh
Keyword(s):  
Heat Pipes ◽  
Thermal Control ◽  
Electronic Equipment ◽  
Radio Electronic

ANALYSIS ON THE EFFECT OF NANO PARTICLES IN WASTE HEAT RECOVERY SYSTEM USING HEAT PIPES BY RSM

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Gunabal S
Keyword(s):  
Response Surface Methodology ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Heat Pipes ◽  
Filling Ratio ◽  
Nano Particles ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Heat Recovery System

Waste heat recovery systems are used to recover the waste heat in all possible ways. It saves the energy and reduces the man power and materials. Heat pipes have the ability to improve the effectiveness of waste heat recovery system. The present investigation focuses to recover the heat from Heating, Ventilation, and Air Condition system (HVAC) with two different working fluids refrigerant(R410a) and nano refrigerant (R410a+Al2O3). Design of experiment was employed, to fix the number of trials. Fresh air temperature, flow rate of air, filling ratio and volume of nano particles are considered as factors. The effectiveness is considered as response. The results were analyzed using Response Surface Methodology

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