Recent ucei_devtech items

Additions to a Design Tool for Visualizing the Energy Implications of California’s Climates

Fri, 17 Apr 2009 00:00:00 +0000

In California there are 16 different climate zones as defined in the California Energy code (Title 24). The code requires slightly different types of buildings in each zone. These different building code requirements make it important for architects, builders, contractors, and homeowners to understand the resources of their unique local climate and how it will influence the performance of their buildings. The objective of this project is to create a tool called Climate Consultant 4.0 that adds a number of features to those in the prior version 3.0, including new graphic screens such as a Monthly Diurnal Averages plot. It also calculates a set of the Top 20 Design Guidelines based on your unique climate, and displays a sketch illustrating how each applies. A new dynamic graphic tutorial has been created to explain the Psychrometric Chart, and how the relationship between air temperature and humidity influences human thermal comfort and HVAC systems design. Climate Consultant...

The Potential of Cellulosic Ethanol Production from Municipal Solid Waste: A Technical and Economic Evaluation

Wed, 15 Apr 2009 00:00:00 +0000

Municipal solid waste (MSW) is an attractive cellulosic resource for sustainable production of transportation fuels and chemicals because of its abundance, the need to find uses for this problematic waste, and its low and perhaps negative cost. However, significant heterogeneity and possible toxic contaminants are barriers to biological conversion to ethanol and other products. In this study, we obtained six fractions of sorted MSW from a waste processing facility in Fontana, California: 1) final alternative daily cover (ADC Final), 2) ADC green, 3) woody waste, 4) grass waste, 5) cardboard, and 6) mixed paper. Application of dilute sulfuric acid pretreatment followed by enzymatic hydrolysis gave the highest sugar yields in cardboard and ADC final fractions at enzyme loadings of 100 mg enzyme protein/g sugars of raw materials. Treatment with our non-catalytic protein detoxification technology before adding enzymes improved sugar yields at low enzyme loading of 10 mg enzyme...

Aluminum Microfoams for Reduced Fuel Consumption and Pollutant Emissions of Transportation Systems

Wed, 14 Jan 2009 00:00:00 +0000

Because of frequent acceleration and slowing down and the high speed of most transportation systems, lightweight structural materials are needed to reduce their energy consumption while maintaining safety. Considering the extensive use of energy intensive transportation systems in the United States even a small increase in energy efficiency will result in significant energy savings and reduction in pollutant emissions. Closed-cell solid foams and microfoams are of particular interest since they are light and feature outstanding combination of mechanical, electrical, acoustic, and thermal properties.

Improving the Energy Performance of Data Centers

Wed, 14 Jan 2009 00:00:00 +0000

Data centers greatly impact California’s natural environment and economy. These buildings host computer equipment that provide the massive computational power, data storage, and global networking that is integral to modern information technology. The concentration of densely packed computer equipment in data centers leads to power demands that are much higher than those of a typical residence or commercial office building. Data centers typically consume 15 times more energy per square foot than a typical office building and, in some cases, may be 100 times more energy intensive (Greenberg et al. 2003). Nationally, data centers consumed 61 Terawatt hours in 2006; equivalent to the practical power generation of more than 10, 1 Gigawatt nuclear power plants (Brown et al., 2007). This is approximately equal to annual electricity consumption for the entire state of New Jersey (EIA, 2006). California has the largest data center market in the U.S., indicating that a significant portion...

Model Studies of Pore Stability and Evolution in Thermal Barrier Coatings (TBCs)

Thu, 24 Jan 2008 00:00:00 +0000

Studies of high-temperature morphological evolution of controlled-geometry surface cavities and of controlled-geometry internalized pores etched into (100) and (111) surfaces of yttria-stabilized zirconia (YSZ) have been conducted. Results show significant crystallography-dependent variations in the morphologies and evolution rates. The terraceledge structures on (100) and (111) YSZ surfaces differ substantially. Internalized pores that are largely or partially bounded by {111} surfaces are particularly stabilized with regard to shape relaxation and axial instability. The results suggest that controlled variation of thermal barrier coating (TBC) texture and microstructure could result in significant changes in stability and lifetimes.

Measurement of Oil and Gas Emissions from a Marine Seep

Tue, 17 Jul 2007 00:00:00 +0000

Understanding the flows of fluids and carbons on continental margins is of great importance to understand their role in carbon budgets one important source of these fluid flows is marine hydrocarbon seeps (cold seeps). Seeps are found on all continental margins (Judd et al., 2002) and are important to global atmospheric budgets of the important greenhouse gas, methane, contributing an estimated 35-45 Tg yr-1 (Etiope and Klusman, 2002). Of this, marine seeps are estimated to contribute ~20 Tg yr-1 (Kvenvolden et al., 2001) or ~13% of natural emissions and primarily arises from methane hydrates and thermogenic source. Methane hydrates are a form of ice that is stable at high pressure and low temperature wherein methane gas is trapped in the ice crystal lattice. Methane hydrate deposits are estimated at 2000 Tg (Collett and Kuuskraa, 1998; Kvenvolden, 1999), and pose a significant climate threat should oceanic warming occur and lead to increased atmospheric greenhouse gases (Kennett...

A New Design Tool for Visualizing the Energy Implications of California's Climates

Tue, 17 Jul 2007 00:00:00 +0000

In California there are 16 different climate zones, as defined in the California Energy Code (Title24). The code requires slightly different types of buildings in each zone. These different building code requirements make it important for people who are designing, building, or maintaining these buildings to understand the unique attributes of their climate and how it will influence the design and performance of their buildings. In this UCEI project we developed a simple, free, easy-to-use, graphic-based computer program called Climate Consultant 3, and we have posted it on the State of California’s Flex Your Power web site and on the UCLA Energy Design Tools web site. Our objective is to make it freely accessible to architects, builders, contractors, and homeowners, etc., to help them understand their local climate and how it impacts their building’s energy consumption.

Modeling the Flow in an Underflow Plenum

Tue, 17 Jul 2007 00:00:00 +0000

The object of this research is to examine the flow in a plenum of an underfloor air distribution system (UFAD). UFAD installations have often performed poorly because the air entering the space through different vents attached to the plenum has different temperatures. The temperature differences vary in time and can be as much as 5 °C from diffuser to diffuser. It is believed that these temperature inhomogeneities are a result of circulating patterns established in the air flow in the plenum, and that these circulations, in turn, are a result of specific supply and plenum geometries. We have carried out laboratory simulations and numerical modeling of the plenum flow in an attempt to establish the dependence of the flow patterns on the supply configurations. We have conducted a systematic study of the flow patterns for different forcing arrangements and discuss the implications for plenum design. In each case the plenum is square in plan form and the configurations studied...

Variability of Gas Composition and Flux Intensity in Natural Marine Hydrocarbon Seeps

Wed, 14 Feb 2007 00:00:00 +0000

The relationship between surface bubble composition and gas flux to the atmosphere was examined at Coal Oil Point seep field, which is located about 3 km offshore of Santa Barbara County, CA in the Santa Barbara Channel. The field research was conducted using a spar buoy designed to simultaneously measure the surface gas flux, the buoy’s position with differential GPS, and collect gas samples. Results show that the gas composition varies by 10-20% at sub-seeps within seep areas. The nitrogen mole fraction correlated directly with oxygen mole fraction (R2 = 0.94) and inversely with methane mole fraction (R2 = 0.97). These data demonstrate that the bubble composition is modified by gas exchange during ascent from the seafloor: dissolved air enters and hydrocarbon gases leave the bubbles. While compositional differences were observed at sub-seeps, there was no relationship between flux and composition. Factors other than seep intensity controls the amount of gas transfer between...

Quantifying the Air Pollution Exposure Consequences of Distributed Electricity Generation

Tue, 1 Nov 2005 00:00:00 +0000

Private sector and governmental organizations have been promoting the deployment of small-scale, distributed electricity generation (DG) technologies for their many benefits as compared to the traditional paradigm of large, centralized power plants. While some researchers have investigated the impact of a shift toward DG in terms of energy use and even air pollutant concentrations, it is also important to evaluate the air pollutant exposure implications of this shift. We conducted a series of case studies within the state of California that combined air dispersion modeling and inhalation exposure assessment. Twenty-five central stations were selected and five air pollutant-emitting DG technologies were considered, including two that meet the 2003 and 2007 California Air Resources Board DG emissions standards (microturbines and fuel cells with on-site natural gas reformers, respectively). This investigation has revealed that the fraction of pollutant mass emitted that is inhaled...

Intelligent Commercial Lighting: Demand-Responsive Conditioning and Increased User Satisfaction

Mon, 26 Sep 2005 00:00:00 +0000

Energy efficiency has recently come to the forefront of energy debates, especially in the state of California. This focus on efficiency has been driven by the deregulation of electrical-energy distribution, the increasing price of electricity, and the implementation of rolling blackouts. Currently, buildings consume over 1/3 of primary energy, and 2/3 of all electricity produced in the U.S. Commercial buildings consume roughly half of this, and lighting is responsible for approximately 40% of commercial building energy use. These numbers indicate that research in lighting efficiency has great potential to positively impact energy efficiency.

Efficient lighting controls proven to save up to 45% in electricity consumption are commercially available. In practice however, these systems are poorly received and greatly under-leveraged, resulting in a missed opportunity for impressive energy savings. Accordingly, we proposed the three-phase extension of an intelligent decision...

Decision-making in Electricity Generation Based on Global Warming Potential and Life-cycle Assessment for Climate Change

Thu, 30 Jun 2005 00:00:00 +0000

The use of an indicator that is based on global climate change effects is important to support decision-makers committed to sustainable development. Our project demonstrated the use of life-cycle assessment (LCA) as a systematic approach to analyzing the construction and upgrade, operation, maintenance, and ultimate decommissioning of electric power plants. A case study of a hydroelectric power plant (Glen Canyon) was completed, including sensitivity analysis.

The LCA performed in this research quantified emissions during different phases of the life of a power plant. The emissions of greenhouse gases (GHGs) were then characterized using the global warming potential (GWP) method. GWP is a method to compare the global climate change effects of different GHGs to that of CO2. It provides a relative assessment of impacts based on selection of specific time frames. However, because the GWP compares the potential impacts of any GHG to the potency of CO2, we decided to use a...

The Spatial Scales, Distribution, and Intensity of Natural Marine Hydrocarbon Seeps near Coal Oil Point, California

Tue, 29 Mar 2005 00:00:00 +0000

Natural hydrocarbon seepage from marine environments is an important source of methane and other gases to the atmosphere. Quantifying this flux is necessary for constraining global budgets and understanding local air pollution sources. A field of strong hydrocarbon seepage offshore of Coal Oil Point near Santa Barbara, California produces extensive areas of bursting bubbles at the sea surface. An instrumented buoy was deployed in the Coal Oil Point field to measure directly the atmospheric gas flux from three seeps of varying size and intensity. Spatial scales of continuity of the seeps, quantified by semivariograms, are small, ranging from < 1 m to about 9 m such that flux values on larger scales are uncorrelated. These de-correlation scales are comparable to the horizontal extents of individual bubble plumes estimated visually at the sea surface. Semivariograms for each seep are used in an ordinary Kriging procedure to interpolate flux measurements onto a regular grid...

Economic Analysis of Hydrogen Energy Station Concepts: Are "H 2E-Stations" a Key Link to a Hydrogen Fuel Cell Vehicle Infrastructure?

Thu, 8 Apr 2004 00:00:00 +0000

Fuel cell vehicles (FCVs) powered directly with hydrogen (H2) will need access to a H2 refueling infrastruture. For this reason, most direct-H2 FCVs introduced prior to 2008-2010 are likely to be placed in fleets where they can be centrally refueled. However, access to additional refueling sites would increase the usefulness of these early FCVs, and once FCV commercialization spreads to the general public, consumers will require at least a minimal H2 refueling infrastructure in order to make FCV use feasible. One option for expanding the infrastructure for FCVs is the concept of the "hydrogen energy station" (H2E-Station). These H2E-Stations seek to capture synergies between producing H2 for a stationary fuel cell electricity generator that provide electricity for local loads, and refueling FCVs with additional high-purity H2 that is produced through the same H2 generation system.

Based on our initial analysis, we conclude that the economics of supporting small numbers...

Modeling Flow and Heat Transfer Through Porous Media for High Heat Flux Applications

Tue, 5 Nov 2002 00:00:00 +0000

Effective heat transfer is essential in a variety of energy technologies in order to enable the maximum possible power density and power conversion efficiency needed for economic competitiveness and fuel conservation. A particularly difficult heat transfer problem exists with gas coolants, due to their inherently low heat capacity and heat transfer coefficient. Innovative techniques have been proposed previously using porous metal heat transfer media infiltrated by the coolant. The general design strategy is to minimize the coolant flow path length in contact with the porous medium, and to minimize the friction factor in that zone while simultaneously maximizing the heat transfer coefficient. In this work we seek to develop improved phenomenological thermal-hydraulic models in order to assess various porous heat transfer media and to help optimize the heat transfer coefficient while minimizing the associated fluid friction in innovative design concepts. The results will...

A Motor-Integrated Parallel Hybrid Transmission

Tue, 5 Nov 2002 00:00:00 +0000

This paper presents a motor-integrated transmission mechanism for use in parallel hybrid electric vehicles. The transmission can provide five basic modes of operation that can be further classified into sixteen sub-modes: one electric motor mode, four engine modes, four engine/charge modes, three power modes, and four regenerative braking modes. Each of these sub-modes can be grouped into like clutching conditions, providing the functional appearance of a conventional 4-speed automatic transmission, with electric launch, engine-only, engine/charge, power-assist, and regeneration capability. CVT capability is provided with one of the engine/charge modes. The kinematics, static torque, and power flow relations for each mode are analyzed in detail. Finally, a notional control strategy is developed. The transmission can be incorporated not only in front-wheel drive but also in rear-wheel drive vehicles. The compactness, mechanical simplicity, and operational flexibility of the...