Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Water System”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Optimization Framework to Assess the Demand Response Capacity of a Water Distribution System

As large electricity consumers, water distribution system (WDS) pumping stations have the potential to become meaningful participants in demand response (DR) programs. The authors propose an optimization framework for assessing the DR capacity of a WDS and identifying the optimal bidding strategy for maximizing WDS revenue in the DR spot market. The proposed mixed integer linear programming (MILP) model overcomes computational constraints of previous DR optimization models by adopting a preprocessing procedure to minimize the number of binary variables and implementing a convex relaxation technique to linearize the hydraulic equations. The proposed MILP model also explicitly accounts for varying levels of risk tolerance of WDS operators by varying the recovery period over which pumping returns to business-as-usual operation. The optimization framework is implemented on a skeletonized 48-node WDS model that includes 7 pumps, 6 tanks, and 39 pipes. Using a simulated DR event and water consumption profile, the authors derive the optimal DR supply curves (i.e., compensation price versus load curtailment quantity) and revenue potential of the WDS under six scenarios for DR participation.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2024

Field Validation of Electrochemical Water Filtration System on Open Loop Cooling Towers at Automotive Plants

Open loop cooling towers play a pivotal role in rejecting heat for chilled water systems serving industrial processes, heating, ventilation, and air conditioning loads. Exposure to outside conditions can present certain operating challenges to system performance including scaling, corrosion, and biological growth. These issues are mitigated through the use of effective cooling tower water filtration and treatment systems to reduce contaminants—along with other total suspended solids (TSS) and total dissolved solids (TDS)—in the system. The U.S. Department of Energy’s Industrial Efficiency and Decarbonization Office is interested in an electrochemical-based filtration system with the ability to remove TSS particulate down to 1 micron. The removal of finer particulates reduces the need for blowdown and, in turn, makeup water use and chemical treatment in the cooling tower. Additionally, the removal process can reduce fouling at the condensers, resulting in better heat exchange and energy savings. Two Industrial Technology Validation program projects validated the electrochemical water filtration system at the Toyota Motor Manufacturing, Mississippi plant in Blue Springs, Mississippi, and the Nissan Canton Vehicle Assembly Plant in Canton, Mississippi. Researchers found that installation of both systems resulted in water and chemical treatment savings with minimal impact on energy use.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
NASA NTRS1986

Water recycling system using thermopervaporation method

A water recycling system concept for the crew of the space station is presented. A thermopervaporation method is a new key technology used for the distillation process, utilizing a hydrophobic membrane. An experimental study of thermopervaporation revealed that the permeation depends on the gap between the membrane and the cooling surface in the condensation room: the steam diffusion occurs with gaps less than 5 mm while natural convection becomes dominant with gaps more than 5 mm. A brief discussion of the system operation is also described.

Nitta, K.↗
NASA NTRS2015

Water Recovery System Design to Accommodate Dormant Periods for Manned Missions

Future manned missions beyond lower Earth orbit may include intermittent periods of extended dormancy. Under the NASA Advanced Exploration System (AES) project, NASA personnel evaluated the viability of the ISS Water Recovery System (WRS) to support such a mission. The mission requirement includes the capability for life support systems to support crew activity, followed by a dormant period of up to one year, and subsequently for the life support systems to come back online for additional crewed missions. Dormancy could be a critical issue due to concerns with microbial growth or chemical degradation that might prevent water systems from operating properly when the crewed mission began. As such, it is critical that the water systems be designed to accommodate this dormant period. This paper details the results of this evaluation, which include identification of dormancy issues, results of testing performed to assess microbial stability of pretreated urine during dormancy periods, and concepts for updating to the WRS architecture and operational concepts that will enable the ISS WRS to support the dormancy requirement.

Tabb, David↗
DOE OSTI2017

Interaction between Heat Pump Water Heaters or Other Internal Point Source Loads and a Central Heating System

Water heating represents approximately 18% of residential energy consumption, or 4.6 quadrillion Btus of source energy use annually (EIA 2009). Heat pump water heaters (HPWHs) offer an efficient option for residential water heating, with the ability to reduce water heating energy consumption by up to 63%. Previous research has demonstrated the laboratory performance of HPWHs and has shown savings of 43 to 62% on water heating energy consumption are possible, based on field tests (Ecotope 2015). In order to achieve such high efficiencies, HPWHs employ a refrigeration cycle to move heat from the ambient air into the water. Therefore, when HPWHs are installed in conditioned space, they will remove heat from that space which can help the HVAC system in the cooling season and require additional energy from the HVAC system in the heating season. This project provides an unbiased evaluation of the space conditioning interactions between a HPWH and the heating system in several locations throughout the home to further our understanding of the impact that HPWHs have on space conditioning loads. This report explores the HPWH interaction factor from several perspectives: (1) a theoretical analysis, (2) a review of previous literature, and (2) an experimental assessment. The experiments were conducted in PNNL’s side-by-side Lab Homes, which provide a platform for evaluating energy-saving and grid-responsive technologies in a controlled environment. The PNNL Lab Homes are two factory-built homes installed on PNNL’s campus in Richland, Washington. The homes represent existing homes, which account for approximately 99% of occupied homes in the U.S. These 1500 ft2 homes have three bedrooms, two bathrooms, and are equipped with 7.7 HSPF heat pump and an electric forced air furnace. Both homes have R-22 floors, R-11 walls and R-22 ceiling insulation levels, with double-pane clear glass windows. The results of this experiment verified that the energy use of the HVAC system increases as a point source cooling load, like a HPWH, is moved closer to the thermostat. The opposite is also true, as a point source heating load is moved closer to the thermostat, the heating load decreases. The results show between 30-40% difference between the interaction that this type of load has when it is placed in the master bathroom compared to the living room for the PNNL Lab Homes.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
NASA NTRSDate not supplied

A Preliminary Modeling Study of Biofilm Accumulation in the Water Recovery System

Bacterial biofilms are ubiquitous in wastewater systems on earth and in spacecraft, such as in the International Space Station (ISS) wastewater processing assembly (WPA), where they cause problems in the tank, solenoid valves, and pipelines. Downstream filter applications, tank cycling, and regular biocide water flushing have been used to control biofilm accumulation on board the ISS. Biofilm control is expected to be a challenge for long-term missions with a dormancy period of up to a year, as stagnant water systems are highly susceptible to biofilm growth. Flushing of the system with biocidal water has been proposed to avoid biomass problems for long-term missions. To validate the proposed flush method, a mathematical model, based on the metabolism maintenance rate of bacteria, is being developed to understand the current biofilm accumulation rate in the ISS WPA system and to calculate the biomass production rate under dormancy-like conditions. This method of quantification of biofilm can be applied as a function of nutrient inputs to guide the selection and optimization of biofilm mitigation approaches. The method can also be helpful in understanding, defining, quantifying, visualizing, and simulating the state of the water processing system during operation and after dormancy.

Angie M Diaz↗
DOE OSTI2022

Coordinated operation of pumped-storage hydropower with power and water distribution systems

Small pumped-storage hydropower (PSH) units have gained popularity as distributed energy storage options that can provide flexibility to the operation of power distribution systems. Optimal operation of small PSH units is not only dependent on the energy storage provided to power distribution system, but also on the inflow and outflow of water from and to the water distribution system. Here, in this context, this paper develops an optimization model for coordinated operation of PSH units with power and water distribution systems. The proposed model optimizes the operation of water tanks, variable-speed pumps and PSH in pumping and generating modes to minimize the operation cost of power distribution system, while respecting the power flow constraints of power distribution and hydraulic constraints of water distribution system. Appropriate electricity tariffs are implemented to avoid additional expenses in water distribution system that can be enforced by its coordinated operation in favor of power distribution system. The proposed model is implemented on a 33-bus and a 123-bus test power distribution system connected to a 16-node test water distribution system. Results demonstrate the effectiveness of proposed model in tapping PSH flexibility to reduce the operation cost of power and water distribution systems, while meeting the power and water demands.

13 HYDRO ENERGY↗
NASA NTRS1979

NASA JSC water monitor system: City of Houston field demonstration

A water quality monitoring system with on-line and real time operation similar to the function in a spacecraft was investigated. A system with the capability to determine conformance to future high effluent quality standards and to increase the potential for reclamation and reuse of water was designed. Although all system capabilities were not verified in the initial field trial, fully automated operation over a sustained period with only routine manual adjustments was accomplished. Two major points were demonstrated: (1) the water monitor system has great potential in water monitoring and/or process control applications; and (2) the water monitor system represents a vast improvement over conventional (grab sample) water monitoring techniques.

Taylor, R. E.↗
NASA NTRS2009

Exploration Life Support Critical Questions for Future Human Space Missions

Exploration Life Support (ELS) is a project under NASA s Exploration Technology Development Program. The ELS Project plans, coordinates and implements the development of advanced life support technologies for human exploration missions in space. Recent work has focused on closed loop atmosphere and water systems for a lunar outpost, including habitats and pressurized rovers. But, what are the critical questions facing life support system developers for these and other future human missions? This paper explores those questions and discusses how progress in the development of ELS technologies can help answer them. The ELS Project includes Atmosphere Revitalization Systems (ARS), Water Recovery Systems (WRS), Waste Management Systems (WMS), Habitation Engineering, Systems Integration, Modeling and Analysis (SIMA), and Validation and Testing, which includes the sub-elements Flight Experiments and Integrated Testing. Systems engineering analysis by ELS seeks to optimize the overall mission architecture by considering all the internal and external interfaces of the life support system and the potential for reduction or reuse of commodities. In particular, various sources and sinks of water and oxygen are considered along with the implications on loop closure and the resulting launch mass requirements.

Ewert, Michael K.↗
NASA NTRSDate not supplied

Biofilm Management in a Microgravity Water Recovery System

Biofilm growth continues to be a significant concern for NASA’s current and future water systems. The International Space Station (ISS) Water Processor Assembly (WPA) produces potable water from a combination of humidity condensate and urine distillate. The WPA waste tank requires significant management to prevent biofilm growth from impacting downstream components. This issue is magnified for future NASA manned missions due to the need to place the vehicle’s life support system in a dormant state during uncrewed operations (e.g., when the vehicle is in Mars orbit during the surface mission). NASA personnel and the Center for Biofilm Engineering at Montana State University are evaluating various methods for mitigating biofilm growth, including reduced nutrient levels, thermal treatment, sonic waves treatment, and identifying effective biocides in this application. This paper provides an overview of the current status of this effort.

Yo-ann Velez Justiniano↗
NASA NTRS1977

Experimental evaluation of a breadboard heat and product-water removal system for a space-power fuel cell designed with static water removal and evaporative cooling

A test program was conducted to evaluate the design of a heat and product-water removal system to be used with fuel cell having static water removal and evaporative cooling. The program, which was conducted on a breadboard version of the system, provided a general assessment of the design in terms of operational integrity and transient stability. This assessment showed that, on the whole, the concept appears to be inherently sound but that in refining this design, several facets will require additional study. These involve interactions between pressure regulators in the pumping loop that occur when they are not correctly matched and the question of whether an ejector is necessary in the system.

Hagedorn, N. H.↗
DOE OSTI2021

Integrated Water-Power System Resilience Analysis in a Southeastern Idaho Irrigation District: Minidoka Case Study

This study investigates the joint water–power system resilience of an irrigation district in southeastern Idaho. Irrigation districts face difficulties in the delivery of water to farmers under drought conditions, during equipment failures, or unplanned infrastructure disruptions. The resilience of interconnected water and power systems can be better analyzed and understood through an integrated approach, using a model that connects the dependencies between the two halves of the system. Using a multi-agent system model capturing both water and power system components, as well as their linkages, we capture the interdependencies of these systems and highlight opportunities for improvement when faced with disruptions. Through simulation scenarios, we examine the system resilience using system performance, quantified as the percentage of met demand of the power and water system, when subjected to drought water year, an unforeseen water demand increase, power outage and dam failure. Scenario results indicate that the effects of low flow years are mostly felt in the power system; unexpected increases in water demand marginally impact irrigation system performance; dams and pumps present vulnerabilities of the system, causing substantial unmet demand during disruptions. Noting the interdependencies between the water–power system halves while leveraging an integrated simulation allows for an insightful analysis of the system impacts during disruptions.

13 HYDRO ENERGY↗
DOE OSTI2020

The Installation of Direct Water-Cooling Systems to Reduce Cooling Energy Requirements for High-Performance Computing Centers

A large cluster of High-Performance Computing (HPC) equipment at the Lawrence Livermore National Laboratory in California was retrofitted with an Asetek cooling system. The Asetek system is a hybrid scheme with water-cooled cold plates on high-heat-producing components in the information technology (IT) equipment, and with the remainder of the heat being removed by conventional air-cooling systems. In order to determine energy savings of the Asetek system, data were gathered and analyzed two ways: using top-down statistical models, and bottom-up engineering models. The cluster, “Cabernet”, rejected its heat into a facilities cooling water loop which in turn rejected the heat into the same chilled water system serving the computer-room air handlers (CRAHs) that provided the air-based cooling for the room. Because the “before” and “after” cases both reject their heat into the chilled water system, the only savings is due to reduction in CRAH fan power. The top-down analysis showed a 4% overall energy savings for the data center (power usage effectiveness (PUE) —the ratio of total data center energy to IT energy— dropped from 1.60 to 1.53, lower is better); the bottom-up analysis showed a 3% overall energy savings (PUE from 1.70 to 1.66) and an 11% savings for the Cabernet system by itself (partial PUE of 1.51). Greater savings, on the order of 15-20%, would be possible if the chilled water system was not used for rejecting the heat from the Asetek system. About 37% of the heat from the Cab system was rejected to the cooling water, lower than at other installations.

Earni, Shankar↗
DOE OSTI2023

Analysis of backwash settings to maximize net water production in an engineering-scale ultrafiltration system for water reuse

Ultrafiltration (UF) has been widely utilized as water pretreatment for different applications especially in water reuse. The UF system operation is characterized by a filtration phase, where particles accumulate on the membrane surface resulting in an increase in the transmembrane pressure (TMP) and a cleaning phase, where foulants are removed through cleaning cycles including physical backwash and chemical-enhanced backwash (CEB). In this study, data from an engineering-scale UF system treating reclaimed wastewater were used to assess the impact of backwashing on the filtration process. TMP backwash trigger, backwash duration, and CEB frequency were purposely varied for a cycle-by-cycle investigation on the net water production, water recovery, initial operating TMP, and filtration cycle duration. As the TMP backwash trigger was varied between 62 and 145kPa, the maximum net water production (63 m 3 /d) was achieved at 103kPa and water recovery remained relatively constant at approximately 92%. Backwash durations of 45, 65, and 85s were performed where both net water production and water recovery yielded similar results (~63 m 3 /d and ~ 91%) compared with 103kPa TMP backwash trigger. The CEB frequency was also lowered from one every three backwashes (1/3) to 1/6 and 1/12 and resulted in decreased net water production and water recovery while the initial TMP increased. Interestingly, the total number of CEBs remained approximately constant regardless of their frequency. In conclusion, results suggest that CEB is an important fouling control process to maximize water production.

42 ENGINEERING↗
DOE OSTI2023

Emerging Technologies Review: Water Reuse Systems for Cooling Tower Applications

This report explores the concept of water reuse systems for cooling tower water makeup, specifically focusing on the use of alternative water sources, and the viability of these systems for Air Force installations and operations. Cooling is a critical requirement for DAF operations, and alternative water supplies that enable cooling tower use during a disruption of utility-supplied water increase Air Force resilience. The components of a water reuse system for cooling towers include alternative water supplies, storage, treatment, and distribution in addition to the cooling tower itself. Alternative water sources are not derived from fresh surface water or groundwater and can provide a redundant water supply to utility supply or to fresh water produced on site.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2015

Building America Case Study: Advanced Controls Improve Performance of Combination Space and Water Heating Systems, Minneapolis, Minnesota

The combined space and water heating systems (combi) uses a high efficiency direct vent burner that eliminates safety issues associated with natural draft appliances. Past research with these systems shows that utilizing condensing water heaters or boilers with hydronic air handlers can provide both space and water heating with efficiencies of 90% or greater. Improved controls have the potential to reduce some of this complexity and boost the measured performance.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2016

Building America Case Study: Indirect Solar Water Heating Systems in Single-Family Homes, Greenfield, Massachusetts

Solar water heating systems are not new, but they have not become prevalent in most of the U.S. Most of the country is cold enough that indirect solar thermal systems are required for freeze protection, and average installed cost of these systems is $9,000 to $10,000 for typical systems on single-family homes. These costs can vary significantly in different markets and with different contractors, and federal and regional incentives can reduce these up-front costs by 50% or more. In western Massachusetts, an affordable housing developer built a community of 20 homes with a goal of approaching zero net energy consumption. In addition to excellent thermal envelopes and PV systems, the developer installed a solar domestic water heating system (SDHW) on each home. The Consortium for Advanced Residential Buildings (CARB), a research consortium funded by the U.S. Department of Energy Building America program, commissioned some of the systems, and CARB was able to monitor detailed performance of one system for 28 months.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗