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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,045 records · Page 58

All sources NASA NTRS DOE OSTI

DOE OSTI2013

Lighting system with thermal management system having point contact synthetic jets

Lighting system having unique configurations are provided. For instance, the lighting system may include a light source, a thermal management system and driver electronics, each contained within a housing structure. The light source is configured to provide illumination visible through an opening in the housing structure. The thermal management system includes a plurality of synthetic jets. The synthetic jets are arranged within the lighting system such that they are secured at contact points.

42 ENGINEERING↗

DOE OSTI2014

System and method for controlling power consumption in a computer system based on user satisfaction

Systems and methods for controlling power consumption in a computer system. For each of a plurality of interactive applications, the method changes a frequency at which a processor of the computer system runs, receives an indication of user satisfaction, determines a relationship between the changed frequency and the user satisfaction of the interactive application, and stores the determined relationship information. The determined relationship can distinguish between different users and different interactive applications. A frequency may be selected from the discrete frequencies at which the processor of the computer system runs based on the determined relationship information for a particular user and a particular interactive application running on the processor of the computer system. The processor may be adapted to run at the selected frequency.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2014

Waste heat recovery system for recapturing energy after engine aftertreatment systems

The disclosure provides a waste heat recovery (WHR) system including a Rankine cycle (RC) subsystem for converting heat of exhaust gas from an internal combustion engine, and an internal combustion engine including the same. The WHR system includes an exhaust gas heat exchanger that is fluidly coupled downstream of an exhaust aftertreatment system and is adapted to transfer heat from the exhaust gas to a working fluid of the RC subsystem. An energy conversion device is fluidly coupled to the exhaust gas heat exchanger and is adapted to receive the vaporized working fluid and convert the energy of the transferred heat. The WHR system includes a control module adapted to control at least one parameter of the RC subsystem based on a detected aftertreatment event of a predetermined thermal management strategy of the aftertreatment system.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2014

Systems and methods for initializing a charging system

Systems and methods are provided for initiating a charging system. The method, for example, may include, but is not limited to, providing, by the charging system, an incrementally increasing voltage to a battery up to a first predetermined threshold while the energy conversion module has a zero-percent duty cycle, providing, by the charging system, an incrementally increasing voltage to the battery from an initial voltage level of the battery up to a peak voltage of a voltage source while the energy conversion module has a zero-percent duty cycle, and providing, by the charging system, an incrementally increasing voltage to the battery by incrementally increasing the duty cycle of the energy conversion module.

42 ENGINEERING↗

DOE OSTI2015

Lighting system with thermal management system

Lighting systems having unique configurations are provided. For instance, the lighting system may include a light source, a thermal management system and driver electronics, each contained within a housing structure. The light source is configured to provide illumination visible through an opening in the housing structure. The thermal management system is configured to provide an air flow, such as a unidirectional air flow, through the housing structure in order to cool the light source. The driver electronics are configured to provide power to each of the light source and the thermal management system.

42 ENGINEERING↗

DOE OSTI2015

Lighting system with thermal management system

25 ENERGY STORAGE↗

DOE OSTI2015

Lighting system with thermal management system

25 ENERGY STORAGE↗

DOE OSTI2016

Development of an Ultrasonic Phased Array System for Wellbore Integrity Evaluation and Near-Wellbore Fracture Network Mapping of Injection and Production Wells in Geothermal Energy Systems

This paper documents our progress developing an ultrasound phased array system in combination with a model-based iterative reconstruction (MBIR) algorithm to inspect the health of and characterize the composition of the near-wellbore region for geothermal reservoirs. The main goal for this system is to provide a near-wellbore in-situ characterization capability that will significantly improve wellbore integrity evaluation and near well-bore fracture network mapping. A more detailed image of the fracture network near the wellbore in particular will enable the selection of optimal locations for stimulation along the wellbore, provide critical data that can be used to improve stimulation design, and provide a means for measuring evolution of the fracture network to support long term management of reservoir operations. Development of such a measurement capability supports current hydrothermal operations as well as the successful demonstration of Engineered Geothermal Systems (EGS). The paper will include the design of the phased array system, the performance specifications, and characterization methodology. In addition, we will describe the MBIR forward model derived for the phased array system and the propagation of compressional waves through a pseudo-homogenous medium.

MBIR↗

DOE OSTI2016

Lighting system with thermal management system having point contact synthetic jets

Lighting systems having unique configurations are provided. For instance, the lighting system may include a light source, a thermal management system and driver electronics, each contained within a housing structure. The light source is configured to provide illumination visible through an opening in the housing structure. The thermal management system includes a plurality of synthetic jets. The synthetic jets are arranged within the lighting system such that they are secured at contact points.

36 MATERIALS SCIENCE↗

DOE OSTI2016

Lighting system with thermal management system having point contact synthetic jets

Lighting systems having unique configurations are provided. For instance, the lighting system may include a light source, a thermal management system and driver electronics, each contained within a housing structure. The light source is configured to provide illumination visible through an opening in the housing structure. The thermal management system includes a plurality of synthetic jets. The synthetic jets are arranged within the lighting system such that they are secured at contact points.

36 MATERIALS SCIENCE↗

DOE OSTI2016

Systems and methods for energy cost optimization in a building system

Methods and systems to minimize energy cost in response to time-varying energy prices are presented for a variety of different pricing scenarios. A cascaded model predictive control system is disclosed comprising an inner controller and an outer controller. The inner controller controls power use using a derivative of a temperature setpoint and the outer controller controls temperature via a power setpoint or power deferral. An optimization procedure is used to minimize a cost function within a time horizon subject to temperature constraints, equality constraints, and demand charge constraints. Equality constraints are formulated using system model information and system state information whereas demand charge constraints are formulated using system state information and pricing information. A masking procedure is used to invalidate demand charge constraints for inactive pricing periods including peak, partial-peak, off-peak, critical-peak, and real-time.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

DOE OSTI2016

Lighting system with thermal management system

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2018

A Sequential Game of Defense and Attack on an Interdependent System of Systems

This research studies the defense strategy of an interdependent system in the face of rational attacks. We propose a sequential game between an attacker and a defender on an interdependent system of systems (SoS) to explore the effect of interdependency on the optimal defense strategy. An algorithm of backward induction isdeveloped to obtain the Nash equilibrium of the game.The attacker is the first mover as he applies an attack strategy on constituent systems that maximize his utility. The defender observes and responds by a defense strategy that maximizes her utility. Both players’ utilities are evaluated as the difference between a player’s reward due to SoS functionality (dysfunctionality) and the cost of the action. The sensitivity analysis compares the effects of different parameters on the attacker’s and defender’s strategies such as the effectiveness of defense (attack), the unit cost of defense (attack) and the interdependency level on constituent systems.

Rao, Nageswara↗

DOE OSTI2019

Systems and methods for improved stability of power systems

The embodiments described herein provide for a system including a processor. The processor is configured to select at least one grid system contingency from a plurality of grid system contingencies. The processor is further configured to derive one or more eigen-sensitivity values based on the at least on grid system contingency. The processor is also configured to derive one or more control actions at least partially based on the eigen-sensitivity values. The processor is additionally configured to apply the one or more control actions for generation re-dispatch of a grid system.

Baone, Chaitanya Ashok↗

DOE OSTI2019

System and method for minimizing transport related performance losses in a flow battery system

A flow battery system and method of operating the system minimizes performance losses. The flow battery system includes at least one cell, a first tank including a liquid electrolyte, a pump operably connected to the first tank and to the at least one cell, and a second electrolyte tank operably connected to the at least one cell. The flow battery system further includes a memory including program instructions stored therein, at least one sensor configured to a generate at least one signal associated with a sensed condition of the battery system, and a controller operably connected to the at least one sensor, the pump, and the memory and configured to execute the program instructions to determine a dead zone condition exists based upon the at least one signal, and control the pump to pulse flow of the liquid electrolyte to the at least one cell based upon the determination.

Knudsen, Edward↗

DOE OSTI2021

System Modeling of the HTTR and Economic Dispatch Model of the Secondary System

High Temperature Gas-cooled Reactors (HTGRs) can be used for the generation of electricity and their process heat can be used to improve the efficiency of chemical processes such as hydrogen production. The JAEA-operated High-Temperature engineering Test Reactor (HTTR-GT/H2) is exploring using the reactor for electricity and hydrogen production. A RELAP5-3D model of the HTTR-GT/H2 secondary system has been developed using design information. The various components and heat exchangers in the secondary system were modeled and results were compared to the design conditions. The results for the sole-power generation mode were shown to fit the design conditions very well. The largest temperature difference was on the order of 7 K, and the largest pressure difference was on the order of 0.05 MPa. The results for the hydrogen cogeneration mode did not match the design conditions nearly as well. The largest temperature difference was about 39 K and the largest pressure difference was about 0.27 MPa at the compressor outlet. The larger differences for the hydrogen cogeneration mode are attributed to the various complex components and the flow being split in the secondary loop. A transient reduction in heat removal capability of the secondary system was investigated. Reactor temperatures are anticipated to rise as a result. The core reactivity response due to this increase in temperature is investigated and is expected to add negative reactivity to the reactor. An economic dispatch model was developed for a nuclear-driven iodine-sulfur cycle system to determine hydrogen sale prices that would make such a system profitable. The study focuses on the development of the economic model and the role that input data plays on final calculated values. It was found that the input electricity prices, whether using historical data or a host of synthetic time histories, produce significantly different breakeven hydrogen sale prices. As such, great care should be used in these economic dispatch analyses to select reasonable input assumptions.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

DOE OSTI2023

Hybrid power system control and operating strategy based on power system state vector calculation

Controlling a hybrid power system includes calculating a power system state vector based on energy demand and a stored data array including a matrix defined by a power system hardware configuration. The control further includes producing a power request based on the power system state vector, and varying a flow of energy amongst energy devices using drive linkages in the hybrid power system based on the power request. Related apparatus, control logic and controller structure is disclosed.

Guo, Fang↗

DOE OSTI2016

A Literature Review and Compilation of Nuclear Waste Management System Attributes for Use in Multi-Objective System Evaluations - 16618

The purpose of this work was to compile a comprehensive initial set of potential nuclear waste management system attributes. This initial set of attributes is intended to serve as a starting point for additional consideration by system analysts and planners to facilitate the development of a waste management system multi-objective evaluation framework based on the principles and methodology of multi-attribute utility analysis. The compilation is primarily based on a review of reports issued by the Canadian Nuclear Waste Management Organization (NWMO) and the Blue Ribbon Commission on America's Nuclear Future (BRC), but also an extensive review of the available literature for similar and past efforts as well. Numerous system attributes found in different sources were combined into a single objectives-oriented hierarchical structure. This study provides a discussion of the data sources and the descriptions of the hierarchical structure. A particular focus of this study was on collecting and compiling inputs from past studies that involved the participation of various external stakeholders. However, while the important role of stakeholder input in a country's waste management decision process is recognized in the referenced sources, there are only a limited number of in-depth studies of the stakeholders' differing perspectives. Compiling a comprehensive hierarchical listing of attributes is a complex task since stakeholders have multiple and often conflicting interests. The BRC worked for two years (January 2010 to January 2012) to 'ensure it has heard from as many points of view as possible'. The Canadian NWMO study took four years and ample resources, involving national and regional stakeholders' dialogs, internet-based dialogs, information and discussion sessions, open houses, workshops, round-tables, public attitude research, web site, and topic reports. The current compilation effort benefited from the distillation of these many varied inputs conducted by the previous studies. The initial set of attributes is intended to provide a starting point for considering potential objectives for evaluating nuclear waste management system options. It is envisioned that this initial set will evolve and be revised as new and additional input is received from stakeholders on various attributes and their relative importance. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗