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A prototype air cycle cooling system, designed for forced cooling of HPOF pipe-type cable, was built under an EPRI contract. Its main components are a turbine and compressor operated on a single high speed shaft and a compact cable. oil to air heat exchanger. Air cooling is supplemented by a spray water system. Tests were conducted on the prototype unit at the EPRI Waltz Mill Cable Test Facility to evaluate its performance and operating characteristics. This paper briefly describes this equipment and presents the results of the test program.

Abstract. The impact of multiphase reactions involving nitrogen dioxide (NO2) and aromatic compounds was simulated in this study. A mechanism (CAPRAM 2.4, MODAC Mechanism) was applied for the aqueous phase reactions, whereas RACM was applied for the gas phase chemistry. Liquid droplets were considered as monodispersed with a mean radius of 0.1 µm and a liquid content (LC) of 50 µg m-3. The multiphase mechanism has been further extended to the chemistry of aromatics, i.e. reactions involving benzene, toluene, xylene, phenol and cresol have been added. In addition, reaction of NO2 with dissociated hydroxyl substituted aromatic compounds has also been implemented. These reactions proceed through charge exchange leading to nitrite ions and therefore to nitrous acid formation. The strength of this source was explored under urban polluted conditions. It was shown that it may increase gas phase HONO levels under some conditions and that the extent of this effect is strongly pH dependent. Especially under moderate acidic conditions (i.e. pH above 4) this source may represent more than 75% of the total HONO/NO2 - production rate, but this contribution drops down close to zero in acidic droplets (as those often encountered in urban environments).

In this paper, a numerical method coupling moment method with circuit theory is used to analyze the influence of the grounding material's property on the performance of grounding grids. It can be seen that for a large grounding grid, when the soil resistivity is small, the influence of both resistivity and permeability of grounding material on the performance of grounding grids is great. If the frequency is not very high, the grounding material's resistivity can affect the performance of the grounding grid obviously. If the frequency is very low or very high, the effect of the grounding material's permeability on the performance of the grounding grid is small, while the effect is obvious at other frequency.

Abstract A 500 L biomass fast pyrolysis Auger reactor was designed, constructed and experimented with biomass of Mesquite (Prosopsis juliflora) and rice straw (Oryza sativa). The thermogravimetric analysis of feed stock and the physico chemical properties of the feed and product bio-crude was done as per ASTM standard. An optimization based on Response Surface Methodology was carried out for the operating parameters chosen as: (1) reactor temperature, (2) feedstock-heat carrier ratio and (3) rotational speed of the auger reactor. The optimum bio-crude yield of 42.6 wt.% was observed at 500 °C, feedstock-heat carrier ratio 1:2 and 30 rpm for mesquite sawdust and 34.6 wt.% at 475 °C, 1:2 ratio and 50 rpm for rice straw. Among the two kinds of feedstock tested, the sawdust yielded better product under identical operating conditions. The final bio-crude have properties similar to the results that was reported in the past and has HHV- higher heating value less than petroleum fuel.

Biodiesel is a fuel generally consisting of a mixture of fatty acid methyl esters (FAMEs) which is used in alternative or in combination with petroleum diesel for its environmental benefits. Biodiesel is conveniently manufactured from vegetable oils by transesterification of triglycerides with methanol. However, the process brings about the concurrent formation of glycerol, which may become an oversupplied chemical if biodiesel production keeps growing. A novel biodiesel-like material (abbreviated as DMC-BioD) was developed by reacting soybean oil with dimethyl carbonate (DMC), which avoided the co-production of glycerol. The main difference between DMC-BioD and biodiesel produced from vegetable oil and methanol (MeOH-biodiesel) was the presence of fatty acid glycerol carbonate monoesters (FAGCs) in addition to FAMEs. In the following study, details regarding synthesis and composition of DMC-BioD are provided along with physical properties relevant for its use as a fuel. In addition, the production of potential pyrogenic contaminants was investigated by analytical pyrolysis and compared with those from MeOH-biodiesel, and the model compounds tristearin, triolein, trilinolein and oleic acid glycerol carbonate ester (OAGC). The presence of FAGCs influenced both fuel and flow properties, while the distribution of main pyrogenic compounds, including polycyclic aromatic hydrocarbons (PAHs), was little affected. Benefits and drawbacks of DMC as a candidate transmethylating reagent for producing biofuel from renewable resources and alternative co-products (glycerol carbonate and glycerol dicarbonate) are discussed.

Abstract The concept of a cTES (for cold Thermal Energy Storage) is experimentally investigated in this paper. It aims at demonstrating its technical relevancy, for arid regions, in improving the efficiency of a dry cooled turbine's condenser. Gain is realized by postponing total or part of the daily heat exhausted from the condenser and shifting the release of the remaining heat during the night-time when the ambient temperatures are lower. The global system consists in a 13 m3 dual-media water/rock thermocline TES connected to a 110 kW heat source and a 100 kW dry cooler. Experiments have been first conducted to validate the thermal storage behavior in well-controlled operations. Then, the thermal storage has been connected in parallel with the dry cooler to highlight the global behavior of the “dry cooler / cTES” cooling system under different operation's conditions. Results confirm that the cTES is able to compensate the performances loss of the dry cooler during daytime in case of high ambient temperature and to evacuate heat and to store cold during nigh-time. The control of the cTES is simple, characterized by continuous and smooth transitions from one mode to another and without discontinuities in performances and operations.

This research examines the economic implications of different designs for a national low carbon fuel standard (NLCFS) for the road transportation sector. A NLCFS based on the average Carbon Intensity (CI) of all fuels sold generates an incentive for fuel suppliers to reduce the measured CI of their fuels. The economic impacts are determined by the availability of low carbon fuels, estimates of which can vary widely. Also important are the compliance path, reference level CI, and the design of the credit system, particularly the opportunities for trading and banking. To quantitatively examine the implications of a NLCFS, we created the Transportation Regulation and Credit Trading (TRACT) Model. With TRACT, we model a NLCFS credit trading system among profit maximizing fuel suppliers for light- and heavy-duty vehicle fuel use for the United States from 2012 to 2030. We find that credit trading across gasoline and diesel fuel markets can lower the average costs of carbon reductions by an insignificant amount to 98% depending on forecasts of biofuel supplies and carbon intensities. Adding banking of credits on top of trading can further lower the average cost of carbon reductions by 5%–9% and greatly reduce year-to-year fluctuations in credit prices.

The division of return stroke current among the arresters and groundings of two unenergized test distribution lines, one horizontally configured and the other vertically configured, was studied at the International Center for Lightning Research and Testing in Florida. The division of return stroke currents for the vertically configured line was initially similar to the division on the horizontally configured line: at the time the return stroke current reached peak value (after one microsecond, or so) the two closest arresters/grounds on both lines passed about 90% of the total current. However, the time during which the return stroke current flowed primarily through the closest arresters to the neutral conductor was significantly shorter on the vertically configured line. On that line, the arrester current was about equally divided among all four arresters after several tens of microseconds. The arrester current division as a function of time measured on the vertical line was successfully modeled using the published VI-characteristic, while the division on the horizontal line after some tens of microseconds was only successfully modeled if the residual voltage of the two arresters closest to the current injection point was reduced by 20%. Based on the triggered lightning current division observed on our line, the minimum energy absorbed in each of the two arresters closest to the strike point during a typical natural first stroke is estimated to be 40 kJ.