Results for “cooling system” — Page 21

DOE OSTI2022

Single-Phase Dielectric Fluid Thermal Management for Power-Dense Automotive Power Electronics

This paper describes the design and performance of a dielectric fluid cooling concept for automotive power electronics. The concept combines a low-thermal-resistance package (which eliminates metalized ceramic substrates) with a high-performance convective cooling strategy (slot jets impinging on finned surfaces). Modeling was first used to design the cooling system to maximize thermal performance and minimize pumping power. Additionally, a prototype was then fabricated, and experiments were conducted to validate the model predictions using three fluids at various fluid flow rates (16.7 cm 3 /s [1 L/min] to 68.3 cm 3 /s [4.1 L/min]) and inlet temperatures (30C and 70C). The final design was compact (120-cm 3 total volume, including heat exchanger and conceptual power modules) and cooled 12 devices (e.g., silicon carbide). The validated model was then used to predict the junction-to-fluid thermal resistance and pumping power for various conditions, including 40C fluid temperature. The results predict thermal resistance values as low as 19 mm 2 K/W are possible using the dielectric fluid cooling approach. The dielectric fluid cooling system is predicted to provide thermal resistance and pumping power values that are approximately 56% and 90% lower, respectively, compared to an automotive power electronics cooling system.

30 DIRECT ENERGY CONVERSION↗

DOE OSTI2020

Cooling Performance Testing of Attaway's Negative Pressure CDU

Attaway is a recently installed High-Performance Computing (HPC) machine at Sandia National Labs that is 70% water-cooled and 30% air-cooled. This machine, supplied by Penguin Computing, uses a novel new cooling system from Chilldyne that operates in a vacuum, preventing water leaks. If water-cooling is to fail, fans inside of each node will ramp up to do 100% of the cooling on Attaway. Various tests were completed on Attaway to determine the robustness of its cooling system as well as its ability to respond to sudden changes in states. These changes include an immediate change from an idle compute load to full load (Linpack) as well as running Linpack without any water cooling from Attaway's CDUs. It was discovered that Attaway could respond to sudden compute load changes very well, never throttling any nodes. When Linpack was run without water cooling, the system was able to operate for a short time before throttling happened.

42 ENGINEERING↗

NASA NTRS1978

System design package for the solar heating and cooling central data processing system

The central data processing system provides the resources required to assess the performance of solar heating and cooling systems installed at remote sites. These sites consist of residential, commercial, government, and educational types of buildings, and the solar heating and cooling systems can be hot-water, space heating, cooling, and combinations of these. The instrumentation data associated with these systems will vary according to the application and must be collected, processed, and presented in a form which supports continuity of performance evaluation across all applications. Overall software system requirements were established for use in the central integration facility which transforms raw data collected at remote sites into performance evaluation information for assessing the performance of solar heating and cooling systems.

Source record↗

NASA NTRS1995

Hemodynamic and Thermal Responses to Head and Neck Cooling in Men and Women

Personal cooling systems are used to alleviate symptoms of multiple sclerosis and to prevent increased core temperature during daily activities. Configurations of these systems include passive ice vests and circulating liquid cooling garments (LCGs) in the forms of vests, cooling caps and combined head and neck cooling systems. However, little information is available oil the amount or heat that can be extracted from the body with these systems or the physiologic changes produced by routine operation of these systems. The objective of this study was to determine the operating characteristics and the physiologic change, produced by short term use of one commercially available thermal control system.

Ku, Yu-Tsuan E.↗

DOE OSTI2022

KIPT ADS Target Cooling Analyses by MCNP/Fluent

This report presents multi-physics analyses of the target cooling system of the accelerator driven system (ADS) of the Kharkiv Institute of Physics and Technology (KIPT) using MCNP and Fluent computer programs. MCNP has been used to transport electrons, gammas, and neutrons, and to calculate the energy deposition in the target using a mesh-tally. The mesh-tally data have been imported in Fluent by a C subroutine that has been compiled and linked to Fluent as a user defined function. The KIPT ADS is in operation and Fluent used the CAD model from the manufacturing process of the target. The Fluent results for the reference case match very well the literature results obtained by STAR-CCM+ during the design phase. Other cases that differ from the reference one have been analyzed; in these cases, it is assumed a malfunction of the electron accelerator control or the primary water coolant pump. The target cooling system operates normally for all the analyzed cases except when the inlet water mass flow rate is decreased. If the water coolant mass flow decreases to 25%, the water maximum temperature exceeds the boiling point. However, the transient analysis showed that the target cooling system can operate for 180 seconds when the inlet water mass flow rate is decreased down by 50%.

42 ENGINEERING↗

DOE OSTI2021

Designing Energy-Efficient Quantum Computers Through Prediction and Reduction of Cooling Requirements for Cryogenic Electronics

Quantum computing has been identified as a “wild card” by the International Energy Agency in predicting future global data center energy usage. This is primarily because both uncertainty in the extent to which quantum computing will be adopted, and uncertainty in the power consumption of individual quantum data centers. Unlike the classical counterparts, quantum computers need to be maintained at near absolute zero, requiring energy-intensive cryogenic cooling systems. Therefore, as quantum computers scale up from existing 50 qubit technology demonstrations to the 10,000 to 100,000 qubit systems that will be able to solve complex problems, the energy consumption of both the electronics and the required cooling systems will also increase. To predict this scaling, this work analyzes the energy requirements for both computation and cooling of quantum hardware. We show that the energy requirements for cooling of quantum computers is determined by several computing system parameters, including the number and type of physical qubits, the operating temperature, the packaging efficiency of the system, and the split between circuits operating at cryogenic temperatures and those operating at room temperature. The energy requirements can then be found based on thermal system parameters such as cooling efficiency and cryostat heat transfer. Analysis of these parameters shows that the energy required for cooling is significantly larger than that required for computation, a reversal from energy usage patterns seen in conventional computing. The results and discussions provide a road-map for creating energy efficient quantum computers through the selection of computer architectures and cryogenic system configurations that minimize cooling requirements.

energy efficiency↗

DOE OSTI2023

Water Recovery From Cooling Tower Plumes

According to studies by the UN and the US State Department, we are on the path to an extreme freshwater shortage by 2030. The US’s largest water withdrawal source is power plants, which account for 39% of total US freshwater withdrawals, mostly for cooling. Cooling towers are the most common cooling system. To solve these problems and enable efficient water- based cooling – Infinite Cooling’s novel technology uses electric fields to ionize the air, charge the escaping water leaving cooling towers and direct the water toward mesh collectors where it collects and gets recycled for use in the cooling system. This technology was developed at MIT and was reduced to practice on a lab-scale prototype, and a prototype at the MIT Cogeneration Power Plant. This DOE award funded taking this technology from a lab-scale prototype to TRL 5 on an operating cooling tower in the field at the MIT Nuclear Research Laboratory. The funding helped to design and optimize an electrostatic plume collection system and test it in high-fidelity lab setting and in actual field conditions on a cooling tower. Throughout the award, Infinite Cooling investigated the formation of plumes on cooling towers, used that information to optimize the design, material and electrical properties of the collection device and quantified the collection yield via flow rate and water quality.

20 FOSSIL-FUELED POWER PLANTS↗

NASA NTRS2013

Feasibility Study of Venus Surface Cooling Using Chemical Reactions with the Atmosphere

A literature search and theoretical analysis were conducted to investigate the feasibility of cooling a craft on Venus through chemical reformation of materials from the atmosphere. The core concept was to take carbon dioxide (CO2) from the Venus atmosphere and chemically reform it into simpler compounds such as carbon, oxygen, and carbon monoxide. This process is endothermic, taking energy from the surroundings to produce a cooling effect. A literature search was performed to document possible routes for achieving the desired reactions. Analyses indicated that on Venus, this concept could theoretically be used to produce cooling, but would not perform as well as a conventional heat pump. For environments other than Venus, the low theoretical performance limits general applicability of this concept, however this approach to cooling may be useful in niche applications. Analysis indicated that environments with particular atmospheric compositions and temperatures could allow a similar cooling system to operate with very good performance. This approach to cooling may also be useful where the products of reaction are also desirable, or for missions where design simplicity is valued. Conceptual designs for Venus cooling systems were developed using a modified concept, in which an expendable reactant supply would be used to promote more energetically favorable reactions with the ambient CO2, providing cooling for a more limited duration. This approach does not have the same performance issues, but the use of expendable supplies increases the mass requirements and limits the operating lifetime. This paper summarizes the findings of the literature search and corresponding analyses of the various cooling options.

Evans, Christopher↗

NASA NTRS2013

Feasibility Study of Venus Surfuce Cooling Using Chemical Reactions with the Atmosphere

A literature search and theoretical analysis were conducted to investigate the feasibility of cooling a craft on Venus through chemical reformation of materials from the atmosphere. The core concept was to take carbon dioxide (CO2) from the Venus atmosphere and chemically reform it into simpler compounds such as carbon, oxygen, and carbon monoxide. This process is endothermic, taking energy from the surroundings to produce a cooling effect. A literature search was performed to document possible routes for achieving the desired reactions. Analyses indicated that on Venus, this concept could theoretically be used to produce cooling, but would not perform as well as a conventional heat pump. For environments other than Venus, the low theoretical performance limits general applicability of this concept, however this approach to cooling may be useful in niche applications. Analysis indicated that environments with particular atmospheric compositions and temperatures could allow a similar cooling system to operate with very good performance. This approach to cooling may also be useful where the products of reaction are also desirable, or for missions where design simplicity is valued. Conceptual designs for Venus cooling systems were developed using a modified concept, in which an expendable reactant supply would be used to promote more energetically favorable reactions with the ambient CO2, providing cooling for a more limited duration. This approach does not have the same performance issues, but the use of expendable supplies increases the mass requirements and limits the operating lifetime. This paper summarizes the findings of the literature search and corresponding analyses of the various cooling options

Evans, Christopher↗

NASA NTRS1978

System design package for solar heating and cooling site data acquisition subsystem

The Site Data Acquisition Subsystem (SDAS) designed to collect data from sensors located on residential or commercial buildings using a solar heating and/or cooling system is described. It takes the data obtained from sensors located on the solar system, processes the data into suitable format, stores the data for a period of time, and provides the capability for either telephone retrieval by the central data processing system or manual retrieval of the data for transfer to a central site. The SDAS is also designed so that it will not degrade the operation of the solar heating/cooling system which it is monitoring.

Source record↗

DOE OSTI2022

Integrated desiccant-based cooling and dehumidification

Integrated systems comprising both i) heat and mass exchange systems and ii) electrolysis stacks are disclosed, together with related methods of use. The disclosed systems cool and/or dehumidify air using two streams of salt solutions as liquid desiccants.

Woods, Jason David↗

DOE OSTI2023

Integrated desiccant-based cooling and dehumidification

Integrated systems comprising both i) heat and mass exchange systems and ii) electrolysis stacks are disclosed, together with related methods of use. The disclosed systems cool and/or dehumidify air using two streams of salt solutions as liquid desiccants.

Woods, Jason David↗

DOE OSTI2023

Integrated desiccant-based cooling and dehumidification

Integrated systems comprising both i) heat and mass exchange systems and ii) electrolysis stacks are disclosed, together with related methods of use. The disclosed systems cool and/or dehumidify air using two streams of salt solutions as liquid desiccants.

Woods, Jason David↗

NASA NTRS2019

The International Space Station (ISS) Port 1 (P1) External Active Thermal Control System (EATCS) Ammonia Leak

Ammonia is used in the Starboard 1 (S1) and Port 1 (P1) External Active Thermal Control System (EATCS) to cool the pressurized modules, and some of the external electrical power distribution hardware. Leaks that develop in these critical cooling systems that deplete in-line tanks can ultimately result in loss of cooling, which can have devastating impacts to the mission, science and crew onboard the ISS. A slow ammonia leak was initially observed from the P1 EATCS in 2011, but later in 2013 the leak rate began to accelerate. The ammonia inventory eventually began to decay exponentially, raising concerns that the inventory could drop to levels where the system would not be operational.The Robotic External Leak Locator (RELL) was built and launched to the ISS to detect and help locate ammonia leaks using the ISS Robotic Arm and remote ground operator control without constant crew involvement. RELL pinpointed the ammonia leak to the two flexible jumper hose assemblies connecting one of two fluid loops in one of the three deployable radiators to the P1 EATCS. The ammonia inside the two hose assemblies and that radiator fluid loop was isolated and vented to space in 2017. This stopped the leak and an Extravehicular Activity was conducted to remove the two hose assemblies so they could be returned to ground for further Test, Teardown and Evaluation (TT&E). The purpose of this presentation is to discuss this leakage scenario and the TT&E efforts.

Cowan, Darnell T.↗

DOE OSTI2021

Advanced Water-Related Technology Performance Development

This U.S. Department of Energy/National Energy Technology Laboratory techno-economic analysis evaluates those parameters having the greatest performance and cost impact on wet flue gas desulfurization (FGD) effluent wastewater treatment systems, and air cooled condensers for dry cooling systems. Two supercritical pulverized coal power plants are considered: 1) an existing plant (modified for surface water discharge and air emissions consistent with limits for existing plants) retrofitted with wet FGD effluent wastewater treatment and 2) a greenfield plant constructed with an air-cooled condenser (ACC). Sensitivity analyses are completed on various process parameters associated with the wet FGD effluent wastewater treatment system and ACC to determine the impact on the net plant efficiency and levelized cost of electricity (LCOE). Research and development targets are recommended for the parameters shown to have the greatest potential impact on cost or performance.

20 FOSSIL-FUELED POWER PLANTS↗

NASA NTRS1978

Preliminary design package for residential heating/cooling system: Rankine air conditioner redesign

A summary of the preliminary redesign and development of a marketable single family heating and cooling system is presented. The interim design and schedule status of the residential (3-ton) redesign, problem areas and solutions, and the definition of plans for future design and development activities were discussed. The proposed system for a single-family residential heating and cooling system is a single-loop, solar-assisted, hydronic-to-warm-air heating subsystem with solar-assisted domestic water heating and a Rankine-driven expansion air-conditioning subsystem.

Source record↗

DOE OSTI2021

Consumer Guide to Home Heating and Cooling

Learn about types of heating and cooling systems, system maintenance, and best practices for saving energy with your heating and cooling. This fact sheet from Energy Saver also includes information on buying a new heating or cooling system; efficiency ratings; and selecting new systems including air conditioners, heat pumps, and furnaces.

heating, cooling, air conditioners, heat pumps, fu↗

DOE OSTI2024

High Energy Cooling

The paper considers methods of particle cooling applicable to beam cooling in high energy hadron colliders at the collision energy. Presently, there are two major methods of the cooling the electron cooling and stochastic cooling. The later, in application to colliders, requires exceptionally large frequency band of cooling system. Presently two methods are considered. They are the optical stochastic cooling (OSC) and the coherent electron cooling (CEC). OSC and CEC are essentially extensions of microwave stochastic cooling, operating in 1-10 GHz frequency range, to the optical frequencies enabling bands up to 30-300 THz. The OSC uses undulators as a pickup and a kicker, and an optical amplifier for signal amplification, while the CEC uses an electron beam for all these functions. We discuss major limitations, advantages and disadvantages of electron and stochastic cooling systems.

43 PARTICLE ACCELERATORS↗