Development of the Radiation Stabilized Distributed Flux Burner, Phase II Final Report

This report covers progress made during Phase 2 of a three-phase DOE-sponsored project to develop and demonstrate the Radiation Stabilized Distributed Flux burner (also referred to as the Radiation Stabilized Burner, or RSB) for use in industrial watertube boilers and process heaters. The goal of the DOE-sponsored work is to demonstrate an industrial boiler burner with NOx emissions below 9 ppm and CO emissions below 50 ppm (corrected to 3% stack oxygen). To be commercially successful, these very low levels of NOx and CO must be achievable without significantly affecting other measures of burner performance such as reliability, turndown, and thermal efficiency. Phase 1 of the project demonstrated that sub-9 ppm NOx emissions and sub-50 ppm CO emissions (corrected to 3% oxygen) could be achieved with the RSB in a 3 million Btu/Hr laboratory boiler using several methods of NOx reduction. The RSB was also tested in a 60 million Btu/hr steam generator used by Chevron for Thermally Enhanced Oil Recovery (TEOR). In the larger scale tests, fuel staging was demonstrated, with the RSB consistently achieving sub-20 ppm NOx and as low as 10 ppm NOx. Large-scale steam generator tests also demonstrated that flue gas recirculation (FGR) provided a more predictable and reliable method of achieving sub-9 ppm NOx levels. Based on the results of tests at San Francisco Thermal and Chevron, the near-term approach selected by Alzeta for achieving low NOx is to use FGR. This decision was based on a number of factors, with the most important being that FGR has proved to be an easier approach to transfer to different facilities and boiler designs. In addition, staging has proved difficult to implement in a way that allows good combustion and emissions performance in a fully modulating system. In Phase 3 of the project, the RSB will be demonstrated as a very low emissions burner product suitable for continuous operation in a commercial installation. As such, the Phase 3 field demonstration will represent the first installation in which the RSB will be operated continuously with a sub-9 ppm guarantee

Development of the Radiation Stabilized Distributed Flux Burner. Phase 1, final report

The RSB was first developed for Thermally Enhanced Oil Recovery steamers which fire with a single 60 MMBtu/hr burner; the California Energy Commission and Chevron USA were involved in the burner development. The burner has also since found applications in refinery and chemical plant process heaters. All Phase I goals were successfully met: the RSB achieved sub-9 ppM NOx and sub-50 ppM CO emissions using high excess air, external flue gas recirculation (FGR), and fuel staging in the 3 MMBtu/hr laboratory watertube boiler. In a test in a 50,000 lb/hr oil field steamer with fuel staging, it consistently achieved sub-20 ppM NOx and as low as 10 ppM NOx. With high CO{sub 2} casing gas in this steamer, simulating external FGR, sub-20 ppM NOx and as low as 5 ppM NOx were achieved. Burner material cost was reduced by 25% on a per Btu basis by increasing the effective surface firing rate at the burner; further reductions will occur in Phase II. The market for 30 ppM and 9 ppM low NOx burners has been identified as package boilers in the 50,000 to 250,000 lb/hr size range (the 30 ppM is for retrofit, the 9 ppM for the new boiler market). Alzeta and Babcock & Wilcox have teamed to sell both boiler retrofits and new boilers; they have identified boiler designs which use the compact flame shape of the RSB and can increase steam capacity while maintaining the same boiler footprint. Alzeta, Chevron, and B & W have teamed to identify sites to demonstrate the RSB in Phases II and III. In Phase II, the RSB will be demonstrated in a 100,000 lb/hr industrial watertube boiler

Holography in the EPRL Model

In this research announcement, we propose a new interpretation of the EPR quantization of the BC model using a functor we call the time functor, which is the first example of a CLa-ren functor. Under the hypothesis that the universe is in the Kodama state, we construct a holographic version of the model. Generalisations to other CLa-ren functors and connections to model category theory are considered.Comment: research announcement. Latex fil

Advanced radiant combustion system. Final report, September 1989--September 1996

Results of the Advanced Radiant Combustion System (ARCS) project are presented in this report. This work was performed by Alzeta Corporation as prime contractor under a contract to the U.S. Department of Energy Office of Industrial Technologies as part of a larger DOE program entitled Research Program for Advanced Combustion Systems. The goals of the Alzeta ARCS project were to (a) Improve the high temperature performance characteristics of porous surface ceramic fiber burners, (b) Develop an Advanced Radiant Combustion System (ARCS) that combines combustion controls with an advanced radiant burner, and (c) Demonstrate the advanced burner and controls in an industrial application. Prior to the start of this project, Alzeta had developed and commercialized a porous surface radiant burner, the Pyrocore{trademark} burner. The product had been commercially available for approximately 5 years and had achieved commercial success in a number of applications ranging from small burners for commercial cooking equipment to large burners for low temperature industrial fluid heating applications. The burner was not recommended for use in applications with process temperatures above 1000{degrees}F, which prevented the burner from being used in intermediate to high temperature processes in the chemical and petroleum refining industries. The interest in increasing the maximum use temperature of the burner was motivated in part by a desire to expand the number of applications that could use the Pyrocore product, but also because many of the fluid sensitive heating applications of interest would benefit from the distributed flux characteristic of porous surface burners. Background information on porous surface radiant burners, and a discussion of advantages that would be provided by an improved product, are presented in Section 2

Simulations of Galactic Cosmic Ray Impacts on the Herschel/PACS bolometer Arrays with Geant4 Code

The effects of the in-flight behaviour of the bolometer arrays of the Herschel/PACS instrument under impacts of Galactic cosmic rays are explored. This instrument is part of the ESA-Herschel payload, which will be launched at the end of 2008 and will operate at the Lagrangian L2 point of the Sun-Earth system. We find that the components external to the detectors (the spacecraft, the cryostat, the PACS box, collectively referred to as the `shield') are the major source of secondary events affecting the detector behaviour. The impacts deposit energy on the bolometer chips and influence the behaviour of nearby pixels. 25% of hits affect the adjacent pixels. The energy deposited raises the bolometer temperature by a factor ranging from 1 to 6 percent of the nominal value. We discuss the effects on the observations and compare simulations with laboratory tests.Comment: Experimental Astronomy, 2008, in pres

Coordination Implications of Software Coupling in Open Source Projects

The effect of software coupling on the quality of software has been studied quite widely since the seminal paper on software modularity by Parnas [1]. However, the effect of the increase in software coupling on the coordination of the developers has not been researched as much. In commercial software development environments there normally are coordination mechanisms in place to manage the coordination requirements due to software dependencies. But, in the case of Open Source software such coordination mechanisms are harder to implement, as the developers tend to rely solely on electronic means of communication. Hence, an understanding of the changing coordination requirements is essential to the management of an Open Source project. In this paper we study the effect of changes in software coupling on the coordination requirements in a case study of a popular Open Source project called JBoss

Source Dimensions in Ultrarelativistic Heavy Ion Collisions

Recent experiments on pion correlations, interpreted as interferometric measurements of the collision zone, are compared with models that distinguish a prehadronic phase and a hadronic phase. The models include prehadronic longitudinal expansion, conversion to hadrons in local kinetic equilibrium, and rescattering of the produced hadrons. We find that the longitudinal and outward radii are surprisingly sensitive to the algorithm used for two-body collisions. The longitudinal radius measured in collisions of 200 GeV/u sulfur nuclei on a heavy target requires the existence of a prehadronic phase which converts to the hadronic phase at densities around 0.8-1.0 GeV/fm$^3$. The transverse radii cannot be reproduced without introducing more complex dynamics into the transverse expansion.Comment: RevTeX 3.0, 28 pages, 6 figures, not included, revised version, major change is an additional discussion of the classical two-body collision algorithm, a (compressed) postscript file of the complete paper including figures can be obtained from Authors or via anonymous ftp at ftp://ftp_int.phys.washington.edu/pub/herrmann/pisource.ps.

Pion Content of the Nucleon as seen in the NA51 Drell-Yan experiment

In a recent CERN Drell-Yan experiment the NA51 group found a strong asymmetry of $\bar u$ and $\bar d$ densities in the proton at $x\simeq0.18$. We interpret this result as a decisive confirmation of the pion-induced sea in the nucleon.Comment: 10 pages + 3 figures, Preprint KFA-IKP(TH)-1994-14 .tex file. After \enddocument a uu-encodeded Postscript file comprising the figures is appende

Composite vertices that lead to soft form factors

The momentum-space cut-off parameter $\Lambda$ of hadronic vertex functions is studied in this paper. We use a composite model where we can measure the contributions of intermediate particle propagations to $\Lambda$. We show that in many cases a composite vertex function has a much smaller cut-off than its constituent vertices, particularly when light constituents such as pions are present in the intermediate state. This suggests that composite meson-baryon-baryon vertex functions are rather soft, i.e., they have \Lambda considerably less than 1 GeV. We discuss the origin of this softening of form factors as well as the implications of our findings on the modeling of nuclear reactions.Comment: REVTex, 19 pages, 5 figs(to be provided on request