Results for “building system optimization” — Page 29

DOE OSTI2022

Development and assessment of a reactor system prognosis model with physics-guided machine learning

Autonomous control systems provide recommendations to help operators in decision-making during plant operations ranging from normal operation to accident management. An important step of autonomous control is prognosis. In nuclear engineering domain, prognosis is the process of predicting future conditions of a system or equipment based on present signs and symptoms of a fault. The prognosis model allows predicting future reactor states for possible candidate control strategies so that the outcomes can be evaluated to determine the best control strategy. The prognosis model requires representing direct relationships between the symptoms and the predictions. In nuclear engineering, computational simulations are approximate representations of the operation of the real system. However, prognosis with computational simulations requires high computation power and time due to possible large number of scenarios. Necessary computation resources can be reduced with machine learning (ML) approach for fast predictions by building a surrogate function using the simulation data. A critical issue is, ML models are ignorant of physical knowledge, and these models approximate statistical relationships between the system variables. This ignorance can produce results that are inconsistent with physical laws, even if an optimal result is achieved from a mathematical point of view. Physics-guided machine learning (PGML) is an approach to tackle this issue. Here, this work formulates and illustrates a framework to guide development and assessment of the ML-based prognosis model for autonomous control systems. The development of the prognosis model considers the training of a ML model which consists of optimizing many aspects of the ML approach. The assessment of the prognosis model considers training data limitations and uncertainties of the ML approach. Prognosis models with standalone ML and PGML are developed and assessed on the loss-of-flow scenario of Experimental Breeder Reactor II. The results indicate that PGML based prognosis model has the best performance compared to other prognosis models.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

DOE OSTI2024

An Empirical Validation of a Constrained Bin Packing Algorithm for a Home Energy Management System

The increasing number of intelligent electrical appliances and home energy management systems provide a big opportunity for demand response services from residential and small commercial buildings to the grid. Simultaneously, direct control of individual devices by utilities can cause communication bottlenecks, as well as coordination and privacy concerns. These challenges can be addressed by combining the constituent devices into a single house battery equivalent for the purposes of demand response, using Minkowski sum and a 2d bin packing problem. However, the well-studied traditional problems have not been tested in a real house, as implementation carries significant challenges of its own. We deploy the packing problem on residential devices in a controllable house. We report the barriers we found, such as charge forecast and scalability of the algorithm, and discuss our solutions. The study serves as an intermediate step between existing theoretical research and possible future steps, such as prototype deployments of systems that provide residential demand response.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

NASA NTRS1992

Improving regional health care in West Africa using current space systems and technology

This paper discusses the issues involved with establishing an integrated satellite health network in West Africa based on currently available technology. The system proposed makes use of a central national facility capable of transmitting and receiving voice/data and video signals from the entire country. Regional, field and local facilities provides timely epidemiologic information, sharing of medical expertise through telemedical consultations, enhances optimized resource distribution and builds a framework for telecommunications for the entire country.

Jemison, Mae C.↗

NASA NTRS1992

Improving regional health care in West Africa using current space systems and technology

This paper discusses the issues involved with establishing an integrated satellite health network in West Africa based on currently available technology. The system proposed makes use of a central national facility capable of transmitting and receiving voice/data and video signals from the entire country. Regional, field and local facilities provide timely epidemiologic information, sharing of medical expertise through telemedical consultations, enhance optimized resource distribution and build a framework for telecommunications for the entire country.

Jemison, Mae C.↗

NASA NTRS2016

The Role of Probabilistic Design Analysis Methods in Safety and Affordability

For the last several years, NASA and its contractors have been working together to build space launch systems to commercialize space. Developing commercial affordable and safe launch systems becomes very important and requires a paradigm shift. This paradigm shift enforces the need for an integrated systems engineering environment where cost, safety, reliability, and performance need to be considered to optimize the launch system design. In such an environment, rule based and deterministic engineering design practices alone may not be sufficient to optimize margins and fault tolerance to reduce cost. As a result, introduction of Probabilistic Design Analysis (PDA) methods to support the current deterministic engineering design practices becomes a necessity to reduce cost without compromising reliability and safety. This paper discusses the importance of PDA methods in NASA's new commercial environment, their applications, and the key role they can play in designing reliable, safe, and affordable launch systems. More specifically, this paper discusses: 1) The involvement of NASA in PDA 2) Why PDA is needed 3) A PDA model structure 4) A PDA example application 5) PDA link to safety and affordability.

Safie, Fayssal M.↗

NASA NTRS2020

50 Years of Spaceflight with Fourier Transform Spectrometers (FTS) Built at NASA GSFC

Over the past 50 years, NASA Goddard Space Flight Center (GSFC) has been developing, building, testing and flying a series of Fourier Transform Spectrometers (FTS). This began with the IRIS instruments on the Earth-orbiting Nimbus satellites and progressed to more sophisticated designs optimized for interplanetary spacecraft sent to Mars and later to the outer solar system. Adaptions have been made over time, including progressively higher spectral resolution, sensitivity, numbers of detectors and complexity. Instrument operating temperatures have decreased to enable remote sensing of the cold giant planet systems. In this paper we describe the historical evolution of this instrument line, comparing and contrasting different aspects such as optical design and materials, detector types and data handling. We conclude by looking towards the future. At present the CIRS-Lite prototype is being tested at NASA GSFC for potential use on a future mission to the ice giants, Uranus and Neptune. Surpassing the previous performance of the Voyager IRIS instruments remains challenging, and new technologies that could enable these measurements are discussed.

Nixon, Conor A.↗

DOE OSTI2022

Role of On-Site Generation in Carbon Emissions and Utility Bill Savings under Different Electric Grid Scenarios

Energy-efficient and sustainable technologies are necessary to lower energy and carbon footprints. Many technologies are being pursued to meet the increasing energy demand in buildings. An attractive option is efficient utilization of available energy resources, including renewables, to support current and future building energy needs while targeting grid resiliency, energy, and environmental security at an affordable cost via on-site cogeneration-based approaches. This must include energy-efficient technologies with lower greenhouse gas emissions and optimized cost, performance, and reliability. This paper presents the economic and environmental benefits associated with power technologies such as thermionics and solid oxide fuel cells. Hybrid configurations consisting of heat pumps, power systems, and renewable photovoltaics in cogeneration and trigeneration modes of operation are presented. The role of such technologies in lowering CO2 emissions while improving energy resiliency and serving the needs of underprivileged communities is discussed. The key barriers of affordability and potential solutions for large-scale implementation of these promising technologies are reviewed. Case studies demonstrating the influence of power rating, electrical efficiency, design configuration, carbon dioxide intensity of the grid, and fuel on annual greenhouse gas emissions are presented for residential and commercial buildings.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2020

Laser-Based Means for Accelerating Nuclear Decay Rate

This project aims to replicate and build upon a reported series of results whereby nuclear decay of unstable species has been accelerated under laser irradiation in the presence of resonantly excited plasmonic nanoparticles. We are currently utilizing a laser system similar to that used within these reports as well as optimizing nanoparticle solution environments in an attempt to replicate reported results or provide alternative pathways that may explain some perceived discrepancies. The current work is being performed with equipment and techniques currently available at SRNL, including nanoparticle synthesis and pulsed lasers for plasmon excitation. The results of these experiments could provide quantitative data that can be used to resolve the discrepancies in the calculations and better estimate the ultimate utility of the process. If verified, this would represent a pathway for using readily available and scalable technology to reduce the long-term radiological storage requirements of certain forms of nuclear waste.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

NASA NTRS1992

Interferometers adaptations to lidars

To perform daytime measurements of the density and temperature by Rayleigh lidar, it is necessary to select the wavelength with a very narrow spectral system. This filter is composed by an interference filter and a Fabry Perot etalon. The Fabry Perot etalon is the more performent compound, and it is necessary to build a specific optic around it. The image of the entrance pupil or the field diaphragm is at the infinite and the other diaphragm is on the etalon. The optical quality of the optical system is linked to the spectral resolution of the system to optimize the reduction of the field of view. The resolution is given by the formula: R = 8(xD/Fd)exp 2 where R = lambda/delta(lambda), x = diameter of the field diaphragm, D = diameter of the reception mirror, F = focal length of the telescope, and d = useful diameter of the etalon. In the Doppler Rayleigh lidars, the PF interferometer is the main part of the experiment and the exact spectral adaptation is the most critical problem. In the spectral adaptation of interferometers, the transmittance of the system will be acceptable if the etalon is exactly adjusted to the wavelength of the laser. It is necessary to work with a monomode laser, and adjust the shift to the bandpass of the interferometer. We are working with an interferometer built with molecular optical contact. This interferometer is put in a special pressure closed chamber.

Porteneuve, J.↗

DOE OSTI2026

Good practices for documenting AI-based studies on energy and buildings

Artificial intelligence has transformed building science research over the past decade, with applications spanning energy modeling, energy prediction, HVAC optimization and controls, fault detection, and occupancy modeling. However, many studies lack adequate documentation of datasets, algorithms, training procedures, and validation methods. Building science research faces additional challenges including inconsistent evaluation metrics, limited generalizability across building types, climates, and significant gaps between experimental studies and deployed systems. This communication provides practical guidance for good practices in documenting and publishing AI-based research following established standards from the computer science and machine learning communities. By adopting frameworks such as Datasheets for Datasets, Model Cards, and standardized reproducibility checklists, researchers can ensure their work meets the rigorous documentation standards necessary for reproducible, comparable, and impactful building science research.

Hong, Tianzhen [Lawrence Berkeley National Laborat↗

DOE OSTI2024

The ECP SICM project: Managing complex memory hierarchies for exascale applications

The Exascale Computing Project (ECP)’s Simplified Interface to Complex Memories (SICM) effort focuses on developing universal interfaces for discovering, managing, and sharing data across complex memory hierarchies. These facilitate the exploitation of emerging memory technologies and support precise control over their various trade-offs such as high-bandwidth versus low-latency, persistent versus ephemeral, high-capacity versus low-capacity, and near-CPU versus near-GPU. SICM comprises three interrelated components: a low-level interface, a high-level interface, and a persistent-heap interface. The low-level SICM interface is intended for system and run-time developers as well as expert application developers who prefer full control of the memory objects used within their application. The high-level SICM interface builds upon the low-level interface, employing application-level profiling and analysis to optimize data management for complex memory hierarchies. The persistent-heap interface provides applications with a persistent memory allocator that can allocate custom C++ data structures in both block-storage and byte-addressable persistent memories.

97 MATHEMATICS AND COMPUTING↗

NASA NTRS1982

A linear decomposition method for large optimization problems. Blueprint for development

A method is proposed for decomposing large optimization problems encountered in the design of engineering systems such as an aircraft into a number of smaller subproblems. The decomposition is achieved by organizing the problem and the subordinated subproblems in a tree hierarchy and optimizing each subsystem separately. Coupling of the subproblems is accounted for by subsequent optimization of the entire system based on sensitivities of the suboptimization problem solutions at each level of the tree to variables of the next higher level. A formalization of the procedure suitable for computer implementation is developed and the state of readiness of the implementation building blocks is reviewed showing that the ingredients for the development are on the shelf. The decomposition method is also shown to be compatible with the natural human organization of the design process of engineering systems. The method is also examined with respect to the trends in computer hardware and software progress to point out that its efficiency can be amplified by network computing using parallel processors.

Sobieszczanski-Sobieski, J.↗

NASA NTRS2017

Overview of NASA Electrified Aircraft Propulsion Research for Large Subsonic Transports

NASA is investing in Electrified Aircraft Propulsion (EAP) research as part of the portfolio to improve the fuel efficiency, emissions, and noise levels in commercial transport aircraft. Turboelectric, partially turboelectric, and hybrid electric propulsion systems are the primary EAP configurations being evaluated for regional jet and larger aircraft. The goal is to show that one or more viable EAP concepts exist for narrow body aircraft and mature tall-pole technologies related to those concepts. A summary of the aircraft system studies, technology development, and facility development is provided. The leading concept for mid-term (2035) introduction of EAP for a single aisle aircraft is a tube and wing, partially turbo electric configuration (STARC-ABL), however other viable configurations exist. Investments are being made to raise the TRL level of light weight, high efficiency motors, generators, and electrical power distribution systems as well as to define the optimal turbine and boundary layer ingestion systems for a mid-term tube and wing configuration. An electric aircraft power system test facility (NEAT) is under construction at NASA Glenn and an electric aircraft control system test facility (HEIST) is under construction at NASA Armstrong. The correct building blocks are in place to have a viable, large plane EAP configuration tested by 2025 leading to entry into service in 2035 if the community chooses to pursue that goal.

aircraft engines↗

NASA NTRS2017

Overview of NASA Electrified Aircraft Propulsion Research for Large Subsonic Transports

NASA is investing in Electrified Aircraft Propulsion (EAP) research as part of the portfolio to improve the fuel efficiency, emissions, and noise levels in commercial transport aircraft. Turboelectric, partially turboelectric, and hybrid electric propulsion systems are the primary EAP configurations being evaluated for regional jet and larger aircraft. The goal is to show that one or more viable EAP concepts exist for narrow body aircraft and mature tall-pole technologies related to those concepts. A summary of the aircraft system studies, technology development, and facility development is provided. The leading concept for mid-term (2035) introduction of EAP for a single aisle aircraft is a tube and wing, partially turbo electric configuration (STARC-ABL), however other viable configurations exist. Investments are being made to raise the TRL level of light weight, high efficiency motors, generators, and electrical power distribution systems as well as to define the optimal turbine and boundary layer ingestion systems for a mid-term tube and wing configuration. An electric aircraft power system test facility (NEAT) is under construction at NASA Glenn and an electric aircraft control system test facility (HEIST) is under construction at NASA Armstrong. The correct building blocks are in place to have a viable, large plane EAP configuration tested by 2025 leading to entry into service in 2035 if the community chooses to pursue that goal.

Jansen, Ralph H.↗

NASA NTRS2017

Overview of NASA Electrified Aircraft Propulsion Research for Large Subsonic Transports

NASA is investing in Electrified Aircraft Propulsion (EAP) research as part of the portfolio to improve the fuel efficiency, emissions, and noise levels in commercial transport aircraft. Turboelectric, partially turboelectric, and hybrid electric propulsion systems are the primary EAP configurations being evaluated for regional jet and larger aircraft. The goal is to show that one or more viable EAP concepts exist for narrow body aircraft and mature tall-pole technologies related to those concepts. A summary of the aircraft system studies, technology development, and facility development is provided. The leading concept for mid-term (2035) introduction of EAP for a single aisle aircraft is a tube and wing, partially turbo electric configuration (STARC-ABL), however other viable configurations exist. Investments are being made to raise the TRL level of light weight, high efficiency motors, generators, and electrical power distribution systems as well as to define the optimal turbine and boundary layer ingestion systems for a mid-term tube and wing configuration. An electric aircraft power system test facility (NEAT) is under construction at NASA Glenn and an electric aircraft control system test facility (HEIST) is under construction at NASA Armstrong. The correct building blocks are in place to have a viable, large plane EAP configuration tested by 2025 leading to entry into service in 2035 if the community chooses to pursue that goal.

aircraft engines↗

DOE OSTI2021

Unbundling Smart Meter Services Through Spatio-Temporal Decomposition Agents in DER-rich Environment

Smart meters and the advanced metering infrastructure (AMI) facilitate distribution system operators (DSOs) to gather information on energy consumption at the customer level. With the increasing penetration of building-level intermittent distributed energy resources (DERs) behind the meter, DER information is not available to DSOs. At the same time, smart meter enables users to participate in grid, with real-time information. Information for behind the meter is needed by user to coordinate building level assets for maximum benefits. The concept of unbundled smart meter (USM) needs agents to decompose smart meter measurements to provide service to DSO as well as customers. In this paper, we propose a Spatio-Temporal Decomposition Agent (STDA) for USM based on Artificial Intelligence (AI). STDA can help users optimize their energy usage, help DSO to utilize building assets for the grid operation. The energy usage strategy developed by STDA is suitable for different users, and can be customized by deep learning (DL) models according to the different energy consumption habits of each user. The power prediction performance results of various DL models and evaluation using a set of data from a Hawaii utility is presented. Furthermore, STDA integration with Home Energy management Systems (HEMS) to manage resources is presented and validated. STDA pre-processes the measurements before model training, and provides the spatio-temporal decomposed forecasting.

42 ENGINEERING↗

DOE OSTI2020

Genetic algorithm optimization of tin–copper graded shielding for improved plutonium safeguards measurements

Plutonium nuclear material safeguards is essential to ensure that states do not divert plutonium to clandestine nuclear weapons programs. Traditional safeguards methods rely on correlated neutron measurements. Detection systems based on organic scintillators, which are sensitive to fast neutrons and photons, are gaining support for use in safeguards applications due to increased capabilities and shorter measurement times compared to the current state-of-the-art. A drawback of organic scintillators in plutonium measurements is data throughput limitations; 241 Am builds up in plutonium samples and emits 60-keV gamma rays with a high specific activity. In this work, a genetic algorithm is used to design graded shielding made of tin and copper to attenuate the 60-keV gamma rays. The shield is designed to limit the attenuation of the higher-energy, fission photons, because fission photons can be used as a signature. The genetic algorithm optimization takes days to run, while a complete search space exploration would take years. The genetic algorithm was run for different levels of 60-keV gamma-ray attenuation, and the thickness of the required shielding layers was determined at each level. Tin–copper shielding was placed in front of an array of organic scintillation detectors for a measurement of approximately 4.5 kg of alpha-phase, weapons-grade plutonium, an AmLi source, and a 252 Cf source. We show that the shield successfully attenuated low-energy, non-fission gamma rays, which significantly improved the organic scintillator performance.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

NASA NTRS2003

An Overview of the NASA Aerospace Flight Battery Systems Program

Develop an understanding of the safety issues relating to space use and qualification of new Li-Ion technology for manned applications. Enable use of new technology batteries into GFE equipment - laptop computers, camcorders. Establish a data base for an optimized set of cells (and batteries) exhibiting acceptable performance and abuse characteristics for utilization as building blocks for numerous applications.

Manzo, Michelle↗