PBMR Technology Development Projects at Stellenbosch University, South Africa

2008 ◽  
Author(s):  
R. T. Dobson
Keyword(s):  
Technology Development ◽  
Cooling System ◽  
Heat Engine ◽  
Organic Rankine Cycle ◽  
Development Program ◽  
Heat Pipes ◽  
Development Projects ◽  
Fuel Temperature ◽  
Two Phase ◽  
Research Activities

PBMR has initiated a research and development program wherein a network of expertise relating to PBMR-specific technology is to be established. As a result of this initiative four specific PBMR sponsored technology development projects have been initiated at Stellenbosch University. The work done and still to be done towards these projects will be presented. The first project relates to the characterization of the flow dynamics of particles (ions, atoms and clusters) in a high pressure and velocity (9 MPa and 120 m/s) stream of helium due to various body-force fields (magnetic, electric and centrifugal); the ultimate objective of this project is to develop a graphite dust and particle scrubbing system. The second project relates to an entirely passive reactor cooling system (RCCS) using thermosyphon-type heat pipes with no pumps and active controls. The third project relates to the fuel temperature measurement under normal and loss of coolant pressure conditions using a fibre-optic Bragg-grating method. A fourth project relates to energy efficiency improvement by the conversion of waste, decay, after and residual heat into electrical power. This project makes use of two-phase closed loop thermosyphon-type heat pipes to transport the heat to an external heat engine, such as free piston type Stirling engine or organic Rankine cycle system. The research activities needed to meet the objectives of the above projects will be presented and discussed in this paper.

Advanced Research and Technology Development Fossil Energy Materials Program

1988 ◽  
Vol 110 (4) ◽  
pp. 670-676
Author(s):  
R. R. Judkins ◽  
R. A. Bradley
Keyword(s):  
Technology Development ◽  
National Laboratory ◽  
Development Program ◽  
Ceramic Composites ◽  
Department Of Energy ◽  
Energy Materials ◽  
Alloy Development ◽  
Fossil Energy ◽  
Oak Ridge ◽  
Research Activities

The Advanced Research and Technology Development (AR&TD) Fossil Energy Materials Program is a multifaceted materials research and development program sponsored by the Office of Fossil Energy of the U.S. Department of Energy. The program is administered by the Office of Technical Coordination. In 1979, the Office of Fossil Energy assigned responsibilities for this program to the DOE Oak Ridge Operations Office (ORO) as the lead field office and Oak Ridge National Laboratory (ORNL) as the lead national laboratory. Technical activities on the program are divided into three research thrust areas: structural ceramic composites, alloy development and mechanical properties, and corrosion and erosion of alloys. In addition, assessments and technology transfer are included in a fourth thrust area. This paper provides information on the structure of the program and summarizes some of the major research activities.

New Thermal Management Systems for Data Centers

2012 ◽  
Vol 4 (3) ◽  
Author(s):  
Mayumi Ouchi ◽  
Yoshiyuki Abe ◽  
Masato Fukagaya ◽  
Takashi Kitagawa ◽  
Haruhiko Ohta ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Single Phase ◽  
Data Centers ◽  
Cooling System ◽  
Heat Pipes ◽  
Air Cooling ◽  
Liquid Cooling ◽  
Two Phase ◽  
Cooling Jacket ◽  
Cooling Methods

Energy consumption in data centers has seen a drastic increase in recent years. In data centers, server racks are cooled down in an indirect way by air-conditioning systems installed to cool the entire server room. This air cooling method is inefficient as information technology (IT) equipment is insufficiently cooled down, whereas the room is overcooled. The development of countermeasures for heat generated by IT equipment is one of the urgent tasks to be accomplished. We, therefore, proposed new liquid cooling systems in which IT equipment is cooled down directly and exhaust heat is not radiated into the server room. Three cooling methods have been developed simultaneously. Two of them involve direct cooling; a cooling jacket is directly attached to the heat source (or CPU in this case) and a single-phase heat exchanger or a two-phase heat exchanger is used as the cooling jacket. The other method involves indirect cooling; heat generated by CPU is transported to the outside of the chassis through flat heat pipes and the condensation sections of the heat pipes are cooled down by coolant with liquid manifold. Verification tests have been conducted by using commercial server racks to which these cooling methods are applied while investigating five R&D components that constitute our liquid cooling systems: the single-phase heat exchanger, the two-phase heat exchanger, high performance flat heat pipes, nanofluid technology, and the plug-in connector. As a result, a 44–53% reduction in energy consumption of cooling facilities with the single-phase cooling system and a 42–50% reduction with the flat heat pipe cooling system were realized compared with conventional air cooling system.

scholarly journals Experimental evaluation of natural convection in the IPR-R1 Triga research reactor at 264 kW and 105 kW

2021 ◽  
Vol 9 (2B) ◽  
Author(s):  
Amir Zacarias Mesquita
Keyword(s):  
Natural Convection ◽  
Technology Development ◽  
Cooling System ◽  
Natural Circulation ◽  
Fuel Temperature ◽  
Operational Parameters ◽  
Reactor Operating ◽  
Core Cooling ◽  
Reactor Pool ◽  
Forced Cooling

In order to study the safety aspects connected with the permanent increase of the maximum steady state power of the IPR-R1 Triga Reactor of the Nuclear Technology Development Center (CDTN), experimental measurements were done with the reactor operating at power levels of 265 kW and 105 kW, with the pool forced cooling system turned off. A number of parameters were measured in real-time such as fuel and water temperatures, radiation levels, reactivity, and influence of cooling system. Information on all aspects of reactor operation was displayed on the Data Acquisition System (DAS) shown the IPR-R1 online performance. The DAS was developed to monitor and record all operational parameters. Information displayed on the monitor was recorded on hard disk in a historical database. This paper summarizes the behavior of some operational parameters, and in particular, the evolution of the temperature in the fuel element centerline positioned in the core hottest location. The natural circulation test was performed to confirm the cooling capability of the natural convection in the IPR-R1 reactor. It was confirmed that the IPR-R1 has capability of long-term core cooling by natural circulation operating at 265 kW. The measured maximum fuel temperature of about 300 oC was lower than the operating limit of 550 oC. It has been proven that without cooling in the primary the gamma dose rate above reactor pool at high power levels was rather high.

Liquid Cooling Network Systems for Energy Conservation in Data Centers

2011 ◽  
Author(s):  
Mayumi Ouchi ◽  
Yoshiyuki Abe ◽  
Masato Fukagaya ◽  
Haruhiko Ohta ◽  
Yasuhisa Shinmoto ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Data Center ◽  
Single Phase ◽  
Cooling System ◽  
Heat Pipes ◽  
Air Cooling ◽  
Liquid Cooling ◽  
Two Phase ◽  
Cooling Systems ◽  
Cooling Methods

Energy consumption in data center has been drastically increasing in recent years. In data center, server racks are cooled down by air conditioning for the whole room in a roundabout way. This air cooling method is inefficient in cooling and it causes hotspot problem that IT equipments are not cooled down enough, but the room is overcooled. On the other hand, countermeasure against the heat of the IT equipments is also one of the big issues. We therefore proposed new liquid cooling systems which IT equipments themselves are cooled down and exhaust heat is not radiated into the server room. For our liquid cooling systems, three kinds of cooling methods have been developed simultaneously. Two of them are direct cooling methods that the cooling jacket is directly attached to heat source, or CPU in this case. Single-phase heat exchanger or two-phase heat exchanger is used as cooling jackets. The other is indirect cooling methods that the heat generated from CPU is transported to the outside of the chassis through flat heat pipes, and condensation sections of the heat pipes are cooled down by liquid. Verification tests have been conducted by use of real server racks equipped with these cooling techniques while pushing ahead with five R&D subjects which constitute our liquid cooling system, which single-phase heat exchanger, two-phase heat exchanger, high performance flat heat pipes, nanofluids technology, and plug-in connector. As a result, the energy saving effect of 50∼60% comparing with conventional air cooling system was provided in direct cooling technique with single-phase heat exchanger.

Development of Advanced Cooling Network Systems for Data Centers

2010 ◽  
Author(s):  
Yoshiyuki Abe ◽  
Mayumi Ouchi ◽  
Masato Fukagaya ◽  
Takashi Kitagawa ◽  
Haruhiko Ohta ◽  
...  
Keyword(s):  
High Performance ◽  
Data Centers ◽  
Cooling System ◽  
Heat Pipes ◽  
Energy Utilization ◽  
Liquid Cooling ◽  
Network Systems ◽  
Two Phase ◽  
Cooling Systems ◽  
Development Organization

Energy utilization in data centers, especially cooling systems for server racks, needs extensive improvement. The present authors proposed advanced cooling network systems for data centers, and R & D activities have been conducted under the so-called Green IT Project sponsored by NEDO (New Energy and Industrial Technology Development Organization). In the present concept, CPUs in servers are cooled down by either direct liquid cooling system or heat pipes with liquid cooling systems in the condensation region. The liquid cooling systems are integrated in each server rack and among server racks. A series of studies on both single phase and two phase narrow channel heat exchangers, high performance heat pipes with self-rewetting fluids and nanofluids for heat transfer enhancement are ongoing. In addition, a prototype server rack with the cooling network systems is also under development toward commercial products. This paper reports the updated status of the present R & D.

Electronics Thermal Management Using Advanced Hybrid Two-Phase Loop Technology

2007 ◽  
Author(s):  
Chanwoo Park ◽  
Aparna Vallury ◽  
Jon Zuo ◽  
Jeffrey Perez ◽  
Paul Rogers
Keyword(s):  
Thermal Management ◽  
High Performance ◽  
Cooling System ◽  
Active Flow Control ◽  
Heat Pipes ◽  
High Heat ◽  
Heat Fluxes ◽  
Significant Advance ◽  
Two Phase ◽  
Phase Loop

The paper discusses an advanced Hybrid Two-Phase Loop (HTPL) technology for electronics thermal management. The HTPL combined active mechanical pumping with passive capillary pumping realizing a reliable yet high performance cooling system. The evaporator developed for the HTPL used 3-dimensional metallic wick structures to enhance boiling heat transfer by passive capillary separation of liquid and vapor phases. Through the testing using various prototype hybrid loops, it was demonstrated that the hybrid loops were capable of removing high heat fluxes from multiple heat sources with large surface areas up to 135cm2 and 10kW heat load. Because of the passive capillary phase separation, the hybrid loop operation didn’t require any active flow control of the liquid in the evaporator, even at highly transient and asymmetrical heat inputs between the evaporators. These results represent the significant advance over state-of-the-art heat pipes, loop heat pipes and evaporative spray cooling devices in terms of performance, robustness and simplicity.

Experimental Study of Effect Factors on Performance of Heat Dissipation of HP Heat Exchanger for LED Cooling System

2012 ◽  
Vol 490-495 ◽  
pp. 2530-2533
Author(s):  
Yun Jun Gou ◽  
Zhong Liang Liu ◽  
Chun Min Wang ◽  
Xiao Hui Zhong
Keyword(s):  
Heat Exchanger ◽  
High Power ◽  
Heat Dissipation ◽  
Environmental Temperature ◽  
Cooling System ◽  
Heat Pipes ◽  
Two Phase ◽  
High Power Led ◽  
Street Lamp ◽  
Two Phase Heat Transfer

A new cooling concept for high power LED street lamp by combining the heat release of high power LED with two-phase heat transfer heat pipes was proposed, and in this paper we study the effect of heat pipe numbers, fins structure and ambient temperature on the performance of heat dissipation of HP heat exchanger. Through experimental results, we found the heat pipes number plays a more importent role on the performance of heat dissipation than the fins material and the final surface temperature will increase with the environmental temperature.

Comparison between Rankine Cycle and Trilateral Cycle in Binary System for Power Generation

2013 ◽  
Vol 464 ◽  
pp. 151-155 ◽  
Author(s):  
Mowffaq Oreijah ◽  
Abhijit Date ◽  
Aliakbar Akbarzadaha
Keyword(s):  
Geothermal Energy ◽  
Power Efficiency ◽  
Heat Recovery ◽  
Electrical Power ◽  
Heat Engine ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Two Phase ◽  
Thermodynamic Cycles ◽  
Higher Power

An experimental validation on laboratory scale has been conducted to investigate and to compare two thermodynamic cycles, Trilateral Flash Cycle (TFC) and Organic Rankine Cycle (ORC). The research covers the heat engine utilizing a hydrothermal resource to compare the performance of TFC and ORC. This research would help to analysis the thermal efficiency and power efficiency for both cycles. TFC shows a higher power production than in ORC for the same applied parameters. ORC, however, can be operated at lower rotational speed than for TFC. This project could help, also, to evaluate the current two phase screw expander for both cycles. It is concluded to propose a larger heat exchanger for TFC as the heat recovery can be more reliable in this cycle than in ORC. This research can be applied to generate electrical power from hydrothermal resources such as geothermal energy and solar thermal.

Two-Phase Thermal Ground Planes: Technology Development and Parametric Results

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Avram Bar-Cohen ◽  
Kaiser Matin ◽  
Nicholas Jankowski ◽  
Darin Sharar
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Technology Development ◽  
Low Cost ◽  
Ground Plane ◽  
Heat Pipes ◽  
Two Phase ◽  
Thermal Expansion Coefficients ◽  
Chip Size ◽  
Expansion Coefficients

Defense Advanced Research Project Agency's (DARPA's) thermal ground plane (TGP) effort was aimed at combining the advantages of vapor chambers or two-dimensional (2D) heat pipes and solid conductors by building thin, high effective thermal conductivity, flat heat pipes out of materials with thermal expansion coefficients that match current electronic devices. In addition to the temperature uniformity and minimal load-driven temperature variations associated with such two phase systems, in their defined parametric space, flat heat pipes are particularly attractive for Department of Defense and commercial systems because they offer a passive, reliable, light-weight, and low-cost path for transferring heat away from high power dissipative components. However, the difference in thermal expansion coefficients between silicon or ceramic microelectronic components and metallic vapor chambers, as well as the need for a planar, chip-size attachment surface for these devices, has limited the use of commercial of the shelf flat heat pipes in this role. The primary TGP goal was to achieve extreme lateral thermal conductivity, in the range of 10 kW/mK–20 kW/mK or approximately 25–50 times higher than copper and 10 times higher than synthetic diamond, with a thickness of 1 mm or less.

Experimental Study of Heat Pipe Exchanger for High Power LED Cooling System

2012 ◽  
Vol 490-495 ◽  
pp. 2278-2281
Author(s):  
Yun Jun Gou ◽  
Xiao Hui Zhong
Keyword(s):  
Heat Pipe ◽  
High Power ◽  
Heat Exchangers ◽  
Heat Dissipation ◽  
Cooling System ◽  
Heat Pipes ◽  
Two Phase ◽  
High Power Led ◽  
Two Phase Heat Transfer ◽  
Pipe Heat

A new cooling concept for high power LED street lamp by combining the heat release of high power LED with two-phase heat transfer heat pipes was proposed, and in this study a series of heat pipes with specific fins structure were developed. Through experimental results, we found the new heat pipe heat exchangers have the features of higher efficiency of heat dissipation and more compact construction which meets the demand of heat dissipation for high power LED than the traditional heat pipe heat exchangers and the new exchanger with outwards-radiate structure has the best heat dissipation performance.

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