Optical Communication Transceiver For X2000; Second Delivery Program
Conceptual design of a multi-functional optical instrument is underway for the X2000-Second Delivery Program.
optical↗
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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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Mars Planetary Network for Human Exploration Era – Potential Challenges and Solutions
During 2016-2017, a study was conducted under the sponsorship of the NASA’s Space Communications and Navigation (SCaN) Program to investigate the deep space communications capacity taking into account the needs of all the present and envisioned future missions toward 2030s. It was soon recognized that planning for human exploration to Mars would impose certain unprecedent challenges, both fiscal and technical, to the current space communications paradigm. Targeting the assumed missions concepts, i.e., Crewed Mission to Phobos (CMTP) and Mars Short Stay Mission (MSSM), a Mars Planetary Network for the human exploration era has been formulated. The activity modeling and network traffic simulation/modeling we performed gave some insight into the technical challenges in space communications for the envisioned human Mars exploration era. Chief among the potential challenges are: (1) the high demand on the deep space network (DSN) assets for achieving the high-rate links, both return and forward, from Mars farthest/farther distance (up to 2.67 AU); (2) the need for resilient, persistent communication coverage for crewed vehicles, on surface and in orbits; (3) the significant period of outage for the Mars-Earth link due to superior solar conjunction; (4) the need for on-demand, simultaneous access to the proximity link by multiple vehicles and astronauts in the exploration zone; (5) the capability of determining precise, real-time, positions of surface vehicles and astronauts by the deep space habitat and/or other tele-operations entities. Solution space to each of the above challenges has been explored and analyzed in the context of the individual problem domain and, more importantly, in conjunction with that for the other challenges. This has led to an end-to-end definition of a Mars Planetary Network that would feature: (1) the fusion of deep space Ka-band and optical communications for achieving Mars-Earth high-rate links taking advantage of the optical/RF hybrid 8m/34m antennas in DSN; (2) the integrated application of the Multiple Spacecraft Per Antenna (MSPA) technique, for return link data acquisition, and the Multiple Uplink Per Antenna (MUPA) technique, for forward link data trasnmission, to reduce the number of 34m beam-wave guide (BWG) antennas needed for the era; (3) the integration of three, arrayed, 34m beam-wave guide (BWG) antennas, to provide a high G/T aperture, with the MSPA/MUPA techniques, and a dual “trunk link”approach to cut down the needed G/T -- hence, reducing the number of 34m antennas, relative to that in the single trunk approach by 50%; (4) the deployment of two areostationary/areosynchronous Mars relay orbiters; one of them could also function as (or be served by) a notional Deep Space Habitat (DSH); (5) the opportunistic deployment of a science orbiter in a Pioneer-6 type orbit, equidistant Mars/Earth, that could also serve as an intermediary relay during the Mars superior solar conjunction perod; (6) the existence of the multi-function Mars proximity link that provides the demand-assigned, multiple access (DAMA) capability; and (7) the provision of tracking observables, by leveraging on the planned Mars orbiting and surface infrastructure, to enable the in-situ navigation for surface and orbiting vehicles. This paper provides the description of the proposed Mars Planetary Network in the human exploration era, the trade-off analysis for the various alternative architectures, and the optimal solutions to the key challenges in defining this end-to-end network.
Cheung, Kar-Ming↗
Maintenance-optimized Modular Robotic Concepts for Planetary Surface ISRU Excavators
Modular robotic concepts are identified and evaluatedover the design and operations/maintenance lifecycle forautonomous Lunar, Mars, and partial gravity planetary surfaceexcavation and in-situ earthworks equipment. In-Situ ResourceUtilization (ISRU) is the exploitation of available resources at thesite of a landed spacecraft on the surface of another planetary body.It is intended that this ISRU excavator concept be capable ofmaterial extraction from native regolith, and will be able to operatein a variety of planetary surface environments after initial shakedownon the moon. Using heritage from highly multi-functional,reconfigurable robotic systems like the All-Terrain Hex-LimbedExtra-Terrestrial Explorer (ATHLETE), Regolith AdvancedSurface Systems Operations Robot (RASSOR), and Marsexploration rovers, we propose a flexible maintenance-optimizedmobility platform concept with quick-connect/disconnect featuresfor robotically swappable excavation implements. Dust toleranttorque transmission, power & data docking, thermal fluidconnectors, and modular avionics and instrumentation will allow forautonomous swapping of tools, replacement of spares, and longtermmaintenance of robotic excavators. The architecture includesmodular tools for conventional excavate / scoop / haul / dump /process functions of a terrestrial mining operation on Earth, but alsowill have the capability to operate and robotically maintain itselfwithout human intervention. The concepts described in this studywill provide a suite of technologies, configurations, and operationsready for inclusion into a final flight-ready excavator system.
Schuler, Jason↗
Vacuum Sealable Container (VSC) and Astronaut Lunar Drill (ALD) for Artemis
Introduction: NASA’s Artemis Program is under development to send first woman and next man to the Moon. Artemis will utilize a suite of new technology for Lunar exploration, including new space vehicles, new space suits, and new Astronaut Tools. Honeybee Robotics has been working with NASA JSC to develop a new Vacuum Sealable Container (VSC) and new Astronaut Lunar Drill (ALD) for the upcoming Artemis missions. Vacuum Sealable Container: Sample return continues to be the “Holy Grail” of space exploration, allowing for the analysis of materials using Earth-based laboratories instead of needing to miniaturize and ruggedize instrumentation for space. The Apollo missions to the Moon had several kinds of Sealable Containers which brought back Lunar samples for analysis [1]. These samples are still being analyzed, fifty years later. The VSC requirements are different from that for Apollo containers and as such, new development was required. One major difference between Artemis samples and those from Apollo is the desire to bring back volatiles which may be part of lunar regolith. The VSC is designed to withstand a high-pressure differential caused by sublimating volatiles. Because of the new, stricter sealing requirements, additional features have been added to the VSC. For example, the seal on the container is required to be more robust, thus required more force to actuate, and the seal must be locked in place with a secondary mechanism. Astronaut Lunar Drill: The ALD is designed to be a multi-functional platform for Lunar sample acquisition. The drill builds on lessons learned from the Apollo Lunar Surface Drill (ALSD), as well as Honeybee’s long history of mechanized sample acquisition devices for space [2]. The main functionality of the ALD is Deep Core Regolith Drilling. Additional functionality includes Surface Rock Coring (SRC), and GeoTech Tools (GTT). The ALD is a rotary-percussive drill designed with deep drilling in mind. The ALD is currently designed to have decoupled rotary and percussion subsystems to allow for maximum battery life and reduced fatigue on the crewmember. Honeybee drill technology will automatically engage the percussion when needed to drill at maximum efficiency. The mechanized drill stand helps improve drilling efficiency; the system utilizes advanced drilling algorithms which only require the crewmember to hold a single switch. Additionally, the stand aids in extraction of deep cores, something which was a problem on Apollo. The SRC functionality of the ALD utilizes Honeybee’s Eccentric Tube Core Breakoff technology to collect and retain rock core samples. This technology has also been infused into the Perseverance rover mission. The ALD is removable from the stand to allow crewmembers to collect samples from large boulders. Bringing back rock cores samples instead of full rocks allows for a wider variety of samples to be returned to Earth for study and puts them in a uniform form-factor for effective sealing and analysis. SRC bits will utilize the power of the drill’s percussion system to drill hard Lunar rocks and expedite sample acquisition. The mechanized stand on the ALD allows for additional attachments for taking geotechnical measurements with a Static Cone Penetrometer (SCP) and a Shear Vane (SV). With the stand, the ALD can take SCP measurements with the touch of a button, storing data for return to Earth. SV measurements utilize the ALD’s Rotary motor to spin the vanes in a controlled manner, getting clean data untampered by human error. References: [1] Bar Cohen and Zacny (2009), Drilling in Extreme Environments - Penetration and Sampling on Earth and Other Planets, Wiley. [2] Bar-Cohen and Zacny, Advances in Terrestrial and Extraterrestrial Drilling, CRC Press. [3] Myrick (2003), Core Break-off Mechanism. US Patent No. 6,550,549 Acknowledgements: This work has been supported by NASA via SBIR Phase 3.
Artemis↗
Microbial Characterization of Heat Melt Compaction for Treatment of Space Generated Solid Wastes
One treatment process in development for solid waste management in space has been the Trash Compaction Processing System (TCPS). Human space mission wastes typically contain large percentages of contaminated wet solid waste. The Heat Melt Compactor (HMC) is being developed to be a multi-function means of water recovery, volume reduction, and the making safe of contaminant-rich trash with the potential for waste stabilization and/or sterilization. To determine the efficacy of the HMC treatment to kill microorganisms in solid waste and remain biologically stable, testing was conducted on three tiles produced by HMC-Gen 2 at Ames Research Center. Samples were shipped to Kennedy Space Center to test for microbial viability after compaction, determine the bio-stability of the HMC disks during storage (43 days), and assess potential airborne contaminate microbial growth on surfaces at low and high humidity conditions. In addition to the products of solid waste processing technologies, there is a concern that the crew might come into contact with hardware surfaces that have been contaminated by microorganisms during waste processing. The extent of microbial surface contamination of waste processing hardware was determined by surface sample swabbing and analysis for total bacterial and yeast counts and cultivable counts of aerobic and anaerobic bacteria, spore-forming bacteria, and fungi. Results indicate that trash processing increased bacterial counts on the surfaces of the compacter. All but one biological indicator spore strip imbedded in the HMC produced tiles were negative for growth after incubation for five days indicating effective sterilization through the heat melt compaction process. Analysis of core samples as well as surface growth of tiles inoculated with Aspergillus niger fungal spores incubated at three levels of humidity indicate that HMC created tiles did not support the proliferation of bacterial and fungal growth.
Mary E Hummerick↗
Exploration Medical Capability Clinical Decision Support System Concept of Operations
The Clinical Decision Support (CDS) project supports the Exploration Medical Capability (ExMC) Element of the Human Research Program (HRP). Specifically, the CDS project addresses the ExMC gap, Medical-701: Enhance medical capabilities within an exploration medical system. For long-duration, deep space missions, computational and data resources will play an important role in maintaining crew health, wellness and performance where the crew will need to be more self-reliant as we enter a new era in space exploration to return to the moon and explore Mars. These ambitious goals will require significant change in in-flight medical care due to constraints on mass, volume, power, crew time, skills reduction over time and medical evacuation capabilities. These constraints make it absolutely necessary to develop transformative solutions using new technologies. Unlike the current paradigm for crew health in low-Earth orbit missions that rely on constant communication with Mission Control, the deep space missions will experience communication delays and possibly, no communications for finite periods of time. Hence, crew health management will benefit from analytics’ capabilities to augment decision support. A comprehensive, multi-functional on-board clinical decision support system (CDSS) will help crews assess and diagnose conditions, decide appropriate responses, and guide the provision of tailored and evidence-based treatments, while reflecting contextual factors and constraints. The context may include present and historical data, viable diagnostic equipment, available supplies and medications, and vehicle and environmental health. Communication time with ground-based personnel is delayed or non-existent during significant portions of the mission so the crew will need to autonomously respond to health, performance and medical situations, particularly those that are unplanned. The CDSS must also provide additional capabilities as complex as training for an emergency situation while augmenting non-expert practitioner skillsets if the Crew Medical Officer (CMO) is incapacitated, and as routine as facilitating delayed communication with flight surgeons on the ground. The CDSS must connect complex issues involving health, wellness, task performance and environmental domains. Furthermore, CDSS functionality will focus on semi-autonomous and autonomous decision-making by the crew that is necessary to address challenges in executing a self-contained medical system that enables health care without assistance from ground clinical experts. The document, ExMC CDSS Architecture Recommendation, (HRP- 48032) establishes a description of the envisioned CDSS architecture. The analytics, descriptive or advanced, contained in a CDSS will interface with the integrated crew health and performance architecture that provides the appropriate data sets. The aim of the CDS project is to develop requirements for a CDSS through a series of test-bed prototype developments and demonstrations.
HRP↗
Radiation Shielding Plasma Sprayed Coatings Heads to International Space Station for MISSE-17 Experiments
NASA's Artemis program aims to return to the moon in search of scientific discoveries and establish a habitat using in-situ resource utilization. However, the past lunar explorations presented challenges, such as thermal cycles, solar and intergalactic cosmic radiation, and severe abrasive interaction of sharp lunar regolith particles[1]–[4].Dust mitigation and radiation shielding have become the most important concerns for lunar structural components and rovers which can fail abruptly without a protective solution. To counter these threats, Plasma Forming Laboratory(PFL) at Florida International University (FIU), in collaboration with NASA, has developed a novel multi-functional coating to protect the components synergistically against abrasion, erosion ,and radiation. The titanium-boron nitride composite coatings were prepared using the atmospheric plasma spray technique from engineered composite powders [5], [6].The coatings were subjected to extensive characterization and tribological study with lunar mare simulant JSC-1A, which shows tremendous improvement in the wear performance. The coatings subjected to neutron radiation shielding experiments at NASA Langley Research Center exhibited significantly improved neutron attenuation capacity compared to the substrate. The coating is selected to undergo radiation exposure on the International Space Station as a part of MISSE-17 (Materials International Space Station Experiment).
Thermal Spray↗
3D Microwave Imaging of Impact Damage in Composites
This presentation presents the results of detecting impact damage in woven composites using a 3D microwave imaging system. The microwave results are compared to laser scanner results. After demonstrating the system on two composite samples, the multi-functionality of the system is discussed. They microwave systems ability to detect changes in permittivity of dielectrics is demonstrated by imaging RTV underneath space shuttle tiles, and the detection of sintered regolith simulant when buried in loose regolith simulant.
William (Cy) Wilson↗
X-57 Cockpit Interface Control Document (ICD-CEPT-006)
The Cockpit Interface Control Document defines the hardware interfaces between the X-57 cockpit and subsystems. It provides locational and operational information in support of ground and flight operations with details on controls and displays that include Modes of Operation, Start-Up and Shut- Down Sequence diagrams and captures the current state of the MOD II Avionics Power Architecture. There is also preliminary information of the MOD III and MOD IV configurations. Microsoft PowerPoint was chosen for the document as early development required frequent meetings with multiple customers including aircraft operators (pilots), ground operations, support contractors and power, instrumentation, and human systems integration engineers and PowerPoint enabled presentations that could be quickly modified based on customer and developer interaction. One of the driving requirements for the cockpit design was to keep the left side panel as close the stock Tecnam panel as possible to reduce the failure risk of flight critical indicators. The original annunciator panel in the left side panel was modified to alert the pilot to failures in critical X-57 subsystems and an operator audio alert capability was added for these subsystems. Power-Up switches for the aircraft low voltage 13.8 VDC systems are located at the bottom of the left side panel and center panel, the same location as the stock Tecnam 13.8 VDC switches. The switches for energizing the high voltage system were located in the overhead panel to reduce the risk of inadvertently energizing the high voltage system during the low voltage power-up sequence. The Cruise Motor ARM switches were also located in the overhead panel and correspond to the same location as the stock Tecnam ignition switches. The stock Tecnam throttle levers and prop pitch levers were retained for the X-57. The throttle levers were renamed torque levers since they controlled the commanded torque to the cruise motors. The prop pitch levers provide a commanded RPM signal to an electronic prop pitch controller. X-57 specific displays, located in the right-side panel, are driven by dedicated sensors that monitor right and left side cruise motor RPM, right and left high voltage “Traction Bus” A and B (voltage, current and power) and the Avionics Bus DC converters (A and B) voltage and current. An X-57 Multi-Function Display (MFD) located in the center panel displays CAN Bus parameters. CAN Bus architecture is not certified for flight so these displays could not be used for safety critical information but were designed to be used for test point information only.
Laura Kushner↗
Crew Health and Performance Integrated Data Architecture (CHP-IDA) Project
BACKGROUND: Future Human Exploration missions introduce a new paradigm as crews move further from the resupply and near real-time ground support typical of Low Earth Orbit missions today. Without immediate support from ground-based personnel, exploration crews will be more reliant on inflight data and technology to respond to emergencies and anomalies. A data architecture to support a new generation of technologies, employing advanced analytical and predictive modeling techniques, is needed to enable crew autonomy. OVERVIEW: The Crew Health and Performance Integrated Data Architecture (CHP-IDA) project funded by NASA’s Exploration Medical Integrated Product Team (XMIPT) is laying a foundation for future in-flight informatics by providing a back-end architecture for collecting, storing, and integrating multiple sources of data generated by and around the crew. CHP-IDA provides a platform for common data models and Application Programming Interfaces to access, integrate, process, and display CHP data (e.g., environmental, exercise, medical, sleep, performance, etc.). This will facilitate the increased situation awareness and decision support required by the crew and remote support of exploration missions. This presentation will describe the currently ongoing effort to develop and evaluate a path-to-flight concept of the CHP-IDA software and its core capabilities. Current integrations will be discussed, including analytics for Extravehicular Activity metabolic rate and data ingestion from a multi-functional integrated medical device. The presentation will also provide examples of scenarios used to demonstrate the CHP-IDA through human-in-the-loop test bed activities as well as examples of appropriate system performance metrics. DISCUSSION: Today, in-flight data is often siloed, unsynchronized, and largely inaccessible in real time. Many data sets require manual entry and/or data transfer between vehicles and the ground. These issues contribute to risks in supporting exploration medical capabilities. The CHP-IDA is a back-end data system providing core capabilities needed for timely and meaningful data insights across CHP domains to crew and remote personnel to enable increased crew autonomy. Future work includes collaboration with additional CHP domains, new technology integrations, and further demonstrations of the IDA within different vehicle and communication latency contexts. LEARNING OBJECTIVES 1. The audience will understand that the CHP-IDA is a back-end system, providing a platform to facilitate access, promote decision tools, and provide meaningful insights to crew and to remote stakeholders during exploration missions. 2. The audience will gain insight into human-centered research and activities used to discover CHP domain data needs and pain points and how this information is used to guide development of the IDA.
Exploration↗
Custom Integration of Multiple Medical Functionalities
INTRODUCTION: Previous spaceflight experience and results from probabilistic risk assessment of spaceflight medical risk have highlighted the need for vital sign measurements, medical scopes, and clinical imaging tools for managing medical conditions during spaceflight. The Human Research Program’s Exploration Medical Capability (ExMC) Element and the Mars Campaign Office’s Exploration Medical Integrated Product Team (XMIPT) have performed ground-based evaluations of two Commercial-off-the-Shelf (COTS) Multi-functional Integrated Medical (MIM) devices, which integrate various medical capabilities together in one device. The key findings from these evaluations are presented in a complementary presentation, leaving this presentation to focus on forward recommendations for customized integration of multiple medical functionalities. KEY COMPONENTS: The key features of a custom integration of multiple medical functionalities includes devices and capabilities that optimally reduce medical risk. The COTS MIM devices incorporated functionality for best supporting Earth-based, emergency, pre-hospital care. Our custom integration will use probabilistic risk assessment tools, such as the Medical Extensible Dynamic Probabilistic Risk Assessment Tool (MEDPRAT), to determine the optimal functionality to include based on medical risk minimization. An additional feature of custom integration includes the ability to adapt to different requirements within different vehicles and/or missions. The COTS MIM devices store data in patient specific records, however, the format of the records is not modifiable, and data are not easily transferred from the MIM device to a central data architecture outside of the manufacturer’s established system. Our concept for custom integration will use devices that have an open application programming interface, which can easily connect to independent data architectures and third-party visualization software. The ultrasound capabilities included within the COTS MIM devices did not satisfy many of the Artemis Research and Operations Working Group’s ultrasound functional needs, and therefore, incorporation of higher quality ultrasound capabilities within a customized integration will be beneficial. The COTS MIM devices included minimal procedural guidance and clinical decision support tools. Supplemental tools of this type would need to be supplied along with the COTS MIM devices if they were to be used operationally, so another advantage of customization is the ability to integrate these support tools along with the medical functionality, for a more streamlined user experience. CONCLUSION: Investigation of a customized integration of medical functionality provides a method for further understanding the needs of a long-term exploration spaceflight medical system. The crew members of these exploration missions will need to operate more and more independently from Earth-based ground support. Therefore, having an optimized, streamlined medical system, which contains the functionality and supporting information needed, while remaining within mission and vehicle constraints, will help to maintain crew health and performance, which is necessary for achieving high levels of mission success.
B E Lewandowski↗
Using Life Cycle Assessment to Inform CBI Research Priorities
Life cycle assessment (LCA) is used within the Center for Bioenergy Innovation (CBI) to provide information about how feedstock agricultural practices, supply chain logistics, biorefinery operating parameters, and the slate of biofuels and products contribute to environmental impacts, and how CBI's research priorities can result in less impactful biofuel supply chains. This poster provides an overview of the LCA methodology used within CBI and focuses on data needs in general and from other CBI teams. Assumptions and simplifications within biofuel LCA studies are reviewed, including options for modeling multi-functional processes. Calculation details for life cycle environmental impacts used within CBI - global warming potential, cumulative energy demand, and the Available Water Remaining indicator - are presented, along with a discussion of carbon intensity as an alternative metric for evaluating sustainable aviation fuel and other biofuels. The process of interpreting impact results to guide research priorities is discussed, with examples drawn from CBI's upcoming manuscript on switchgrass yield and cell wall composition.
bioenergy↗
Residential Integrated Heat Pump to Meet All the Home Comfort Needs
This paper will introduce development and field trial of a residential air-source integrated heat pump for cold climates. The heat pump is multi-functional to meet all the home comfort demands, including space cooling, space heating, domestic water heating. The integrated heat pump is an ideal solution to decarbonize northern homes via providing efficient space heating and water heating to replace natural gas. It uses a three-stage compressor and a single set of heat exchangers and valves to deliver all the functions, and thus achieve cost reduction. We developed an innovative system configuration and related controls to solve typical charge unbalance, accelerate charge migration and smoothen mode transition in integrated heat pumps. Laboratory investigations were conducted for individual modes and verified the control functions. Laboratory tests demonstrated that the unit delivered outstanding performance. It achieved 17.0 SEER (seasonal cooling energy efficiency rating) and 11.0 HSPF (heating seasonal performance factor). In the most efficient mode (combined space cooling and water heating mode), the unit reached a total energy efficiency > 30.0 EER and required only 25 minutes to heat a 50-gallon tank of water. One heat pump prototype is going through a field trial since April, 2023 in Syracuse, New York. The one-year field test results are summarized.
Shen, Bo↗
Dynamic Simulation Modeling and Control of a Desiccant Assisted Direct-expansion Air Handling Unit
Desirable built environments demand simultaneous regulation of thermal comfort and indoor air quality (IAQ) with energy-efficient operation of heating, ventilation and air conditioning (HV AC) systems, which involves controls of temperature, humidity and airborne contaminants simultaneously. This paper presents the efforts of dynamic modeling and initial development control strategy for a desiccant-assisted multi-functional air handling unit (AHU) coupled with a direct-expansion rooftop unit (RTU) system, which aims to achieve multiple functions for indoor environment conditioning with energy efficient control. The RTU-AHU system includes a desiccant wheel for dehumidification and a conceptual direct air capture (DAC) filtering device for CO2 regulation. A Modelica-based dynamic model is developed for this conceptual system, and a simple decentralized control strategy is designed, which combines a differential-enthalpy based AHU return-air ratio control, a demand-controlled ventilation, and supply-air temperature humidity control via the RTU and DW controls. The proposed control method is evaluated with the Modelica simulation model for a selected set of scenarios
Pan, Chao↗
The Role of Cu Species in the Regeneration of a Coked Cu/BEA Zeolite Catalyst
Active site occlusion by carbon species, often referred to as coke, is a common deactivation mechanism for heterogeneous catalysts. While it is known that transition metals can lower the temperature required for oxidative coke removal, the roles of ionic species and metal nanoparticles in coke removal are not well understood. This work aims to differentiate how ionic and nanoparticle Cu sites catalyze oxidative regeneration of a coked beta (BEA) zeolite catalyst. This was accomplished by synthesizing catalysts containing exclusively CuOx nanoparticles (NPs) or Cu2+ ions supported on BEA, physically mixing Cu/BEA with a coked BEA catalyst, and monitoring coke removal using in situ spectroscopy. Our results point to an improved combustion activity for CuOx NPs relative to Cu2+ ions, especially in the combustion of graphitic-type coke species. This improved understanding of coke combustion in transition metal containing catalysts informs strategies to improve catalyst regeneration, thereby increasing operational lifetimes.
BIOMASS FUELS,INORGANIC, ORGANIC, PHYSICAL, AND AN↗
Energy Analysis of Combi Heat Pump System Configurations for Space Conditioning and Domestic Hot Water Heating in Residential Buildings
Combi heat pump systems, also referred to multifunctional variable refrigerant flow heat recovery (MF-VRFHR) systems, are specifically designed for residential applications to manage both space conditioning and domestic hot water (DHW). They have attracted attention due to their potential for energy conservation through heat recovery. The incorporation of a hot water tank introduces various system configurations, each characterized by distinct pros and cons related to energy efficiency, system stability, and maintenance. Despite this, a critical gap exists as the specific energy performance remains unquantified under diverse operational modes (e.g., heating mode and heat recovery mode). This paper aims to bridge this gap by conducting a comprehensive comparative analysis of two prevalent system configurations while considering feasible proposed control logics. Configuration 1 integrates a separate hot water tank and a refrigerant-to-water heat exchanger (HEX), also known as a Hydro Kit while Configuration 2 incorporates a refrigerant-wrapped hot water tank. To facilitate this analysis, we developed high-fidelity system models for both configurations in Modelica, capturing system dynamics and detailed control sequences effectively. These system models were built upon the TIL library for HVAC equipment components and the Buildings library for residential building thermal load calculations. The validation of the simulation testbed utilized data from experiments conducted in the PNNL lab home for Configuration 1. To establish the simulation testbed for Configuration 2, we extended the modeling setup derived from Configuration 1. This extension specifically involved substituting the separate hot water tank and Hydro Kit with a refrigerant-wrapped hot water tank of similar sizing sourced from an actual product. The simulation analysis of heating-only and heat recovery modes reveals that Configuration 2 not only saves energy and maintains warmer tank temperatures but also demonstrates faster water heating capabilities. This is attributed to decreased energy loss and improved heat transfer. The study encompasses a wide range of scenarios, considering diverse thermal loads and water usage patterns across heating and heat recovery modes. Overall, the comprehensive results indicate that Configuration 2 achieves energy savings ranging from 3.5% to 12.2% compared to Configuration 1, depending on factors such as water usage patterns, thermal loads, and operational modes.
Configuration, Comparison, Multi-functional, Resid↗
Multifunction Automater Crawler -Inspection Module (MAC-IM): adaptation of space technology to aircraft NDE
Explore the source record for details and available documents.
composite materials inspection of aircraft Telerob↗
Mars Sample Return Earth Entry Vehicle Design:can the Reliability Requirement Be Met by Emerging New Technologies?
This proposed presentation will review past efforts and assess what emerging technologies could be used to address the reliability requirements for a Mars Sample Return Mission.
Ablative TPS↗