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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 Fouling is one of the most significant problems for internally enhanced tubes installed in the shell and tube condensers. Due to the lack of long-term test data, current fouling models are developed based on accelerated particulate fouling tests that have the low precision and hence are inapplicable for predicting combined fouling in most practical cooling tower systems. In addition, the constant values of fouling resistance (factor) recommended by the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) are extremely limited under different operating conditions. To overcome these challenges, this research developed and validated two fouling prediction models based on experimental long-term tests. One of the models was in the form of a ratio of asymptotic fouling resistance of the enhanced tube to that of the plain tube ( R f ∗ / R f , p ∗ ), and the other one was in the form of the asymptotic fouling resistance of the directly enhanced tube ( R f ∗ ). Both models considered water quality, water velocity, and the tube geometries as the variables with the acceptable accuracy for prediction. 1) For the water quality, the parameter of valid concentration ( C com ) of cooling water was defined in this study, which reflected the potential amount of valid components to form the fouling. 2) For the water velocity, its impacts on the two critical parameters of the fouling process: sticking probability ( P ) and deposit bond strength ( ξ ) were investigated using experimental studies. Test results showed that in enhanced tubes with the increased water velocity the sticking probability ( P ) decreased continuously while the deposit bond strength (ξ) initially increased, and then, decreased. 3) For the tube geometries, by taking the parameters of tube geometries as variables the multi-variable correlations of the sticking probability ( P ) and deposit bond strength ( ξ ) were developed. From the results the generalized fouling prediction model as a ratio of asymptotic fouling resistance ( R f ∗ / R f , p ∗ ) was recommended for the application in HVAC&R industry due to its suitability and accuracy in practical project applications.

The natural hydrology of streams and rivers is being extensively modified by human activities. Water diversion, dam construction, and climate change have the potential to increase the frequency and intensity of low-flow events. Flow is a dominant force structuring stream aquatic insect communities, but the impacts of water diversion are poorly understood. Here we report results of an experimental stream flow diversion designed to test how aquatic insect communities respond to a low-flow disturbance. We diverted 40% to 80% of the water in three replicate streams for three summers, leading to summer flow exceedance probabilities of up to 99.9%. Shifts in habitat availability appeared to be a major driver of aquatic insect community responses. Responses also varied by habitat type: total insect density decreased in riffle habitats, but there was no change in pool habitats. Overall, the total biomass of aquatic insects decreased sharply with lowered flow. Collector-filterers, collector-gatherers, and scrapers were especially susceptible, while predatory insects were more resistant. Despite extremely low flow levels, there was no shift in aquatic insect family richness. The experimental water withdrawal did not increase water temperature or decrease water quality, and some wetted habitat was always maintained, which likely prevented more severe impacts on aquatic insect communities.

Abstract Renewable energy sources (RES) coupled to desalination offers a promising prospect for covering the fundamental needs of power and water in remote regions, where connection to the public electrical grid is either not cost effective or not feasible, and where the water scarcity is severe. Stand-alone systems for electricity supply in isolated locations are now proven technologies. Correct matching of stand-alone power supply desalination systems has been recognized as being crucial if the system is to provide a satisfactory supply of power and water at a reasonable cost. The paper covers plants installed since 1990 on the coupling of the two technologies. The main driver promoting the take up of this technology is that water is a limiting factor for many countries in the Mediterranean region. This paper presents the two technologies, RES desalination, and describes the most promising couplings such as PV–reverse osmosis, wind-mechanical-vapor compression, geothermal-multieffect distillation, etc as well as technologies selection guidelines. Also, included applications and lessons learned from specific applications as well as data on the economics. RES for desalination is an important challenge and useful work has been done. However in order to provide practical viable plants, much remains to be done.

Abstract Hydrogen sulphide is likely to become more common in produced hydrocarbon fluids, as the exploitation of deep reservoirs increases and unconventional resources get recovered significantly, such as heavy oils or bitumen. Hydrogen sulphide presence in produced oil and gas results in operational, environmental and treatment problems. Therefore, understanding the origin and the amount of hydrogen sulphide in petroleum reservoirs has great importance for petroleum engineers. Three natural processes are set forth to explain the generation of H 2 S in reservoirs: bacterial sulphate reduction, thermal cracking and thermochemical sulphate reduction (TSR). It is the TSR that leads to the largest amount of H 2 S. This phenomenon involves hydrocarbon oxidation and sulphate reduction and produces as by-products, hydrogen sulphide, carbon dioxide, carbonate minerals and heavy organo-sulphur compounds. The reaction mechanisms of TSR, as well as its kinetics, are not yet fully understood. In this paper, we checked the thermodynamic feasibility of TSR, at temperatures prevailing in the reservoirs where TSR is encountered. Firstly, we calculated the Gibbs energy of the reactions proposed by Worden and Smalley (Worden R.H. and Smalley P.C., 1996, H 2 S producing reactions in deep carbonate gas reservoirs: Khuff Formation, Abu Dhabi, Chem. Geol., 133, p. 157–171). We concluded that they are thermodynamically possible from 25 °C, confirming thermodynamic data published by Anisimov (Anisimov L., 1978, Conditions of abiogenic reduction of sulfates in oil and gas bearing basins, Geochem. Int., 15, p. 63) and Yue and co-workers (Yue C., Li S., Ding K., Zhong N., 2003, Study of thermodynamics and kinetics of CH4–CaSO 4 and H 2 S–Fe 2 O 3 systems, Chinese J. chem. Eng., 11, (6), p.696–700., Yue C., Li S., Ding K., Zhong N., 2006, Thermodynamics and kinetics of reaction between C1–C3 hydrocarbons and calcium sulfate in deep carbonate reservoirs, Geochem. J., 40, 87–94). Secondly, we used a non-stoichiometric approach without any pre-requisite chemical scheme this time. We calculated the Gibbs Energy of chemical systems composed by hydrocarbons, sulphur, anhydrite and water. The minimization of the Gibbs Energy lead to find the most probable chemical systems at steady state. Our theoretical results are consistent with the chemical schemes set forth for TSR by Orr (Orr W., 1977, Changes in Sulfur Content and Isotopic Ratios of Sulfur during Petroleum Maturation — study of Big Horn Basin Paleozoic Oils, in R. Campo and J. Goni Eds, Advances in onorganic geochemistry, Madrid Spain, Enadimsa, p. 571–595), by Worden and Smalley (Worden R.H. and Smalley P.C., 1996, H 2 S producing reactions in deep carbonate gas reservoirs: Khuff Formation, Abu Dhabi, Chem. Geol., 133, p. 157–171) and by Machel (Machel H.G., 2001, Bacterial and thermochemical sulfate reduction in diagenetic settings — old and new insights, Sedimentary Geology, 140, p. 143–175). Moreover, they are in concordance with some in-situ observations: anhydrite and hydrocarbon consumption with simultaneous formation of calcite, hydrogen sulphide and water. Our results showed as well that the larger the number of the carbon atoms in the reactant hydrocarbons, the more irreversible the reaction is.

SummaryStudies investigated the patient‐care (in‐hospital) and outside‐the‐hospital energy consumptions for delivering the hemodialysis (HD) service. A life cycle inventory methodology was used for this patient‐based analysis for two hospitals located in Wichita, Kansas. It was found that, for both hospitals, the actual HD machines consumed approximately 3.5 kilowatt‐hours (kWh) of electrical energy per HD, only 8% to 16% of the total energy used for delivering the HD service (in hospital). This increases to 9.6 to 28.9 kWh of hospital billable energy for the whole system of HD machine, auxiliaries, and dialysis water treatment. Converting these hospital direct electrical energy values to natural resource energy (nre) then adding the cradle‐to‐gate natural resource energy for the manufacturing and supply chain of all the HD consumables, the total is 78 to 149 kWh nre/HD. The nre measures all the direct fuel burned to generate energy and is thus directly related to emissions to the air, water, and land and is a direct secondary impact on public health from HD. The ratio of outside‐the‐hospital energy to direct hospital HD electrical energy consumption is 4:1 to 7:1, so a broader base exists for improvement than just the hospital.

Abstract Hydraulic ram pump (HRP), also known as hydram, lifts water without using external power input. Its low performance combined with affordability of fuels has put this otherwise longstanding technology in the backburner of science and research for a long time, yielding to electric or fuel powered pumps. However, growing concerns about the impacts of fossil fuel use on the environment as well as the rising price of electricity has generated a renewed interest in such technology. The ram pump's operation in remote areas where power grid is not available adds research value on the technology. In this project, a novel approach, i.e., adding thermal energy to the flow to assist the water hammer pressure was modeled. Computational fluid dynamics (CFD) simulation was conducted using ansys. The results were validated experimentally in a 32 mm (27 mm internal diameter) drive pipe and a supply head of 2.18 m ram pump. The Analytical approach was more conservative. The results between simulation and experiment were fairly consistent, with only 6.99% error for pressure, and 10.16% for flowrate. The results show that pressure increased from 183.33 kPa to 342.32 kPa when thermally assisted to reach 150 °C. The experimental discharge flow increased from 11.72 l/min to 16.41 l/min for the corresponding temperature, a 42.01% increase.

Abstract Recent results of GDF SUEZ Research and Innovation Division (RID) activities on Compressed Natural Gas (CNG) vehicles are depicted in this paper: • The prototype “Toyota Prius II Hybrid CNG Vehicle”, developed with IFP Energies Nouvelles, combines a natural gas thermal engine with a hybrid electric motorization. After optimization, CO2 emissions, measured on chassis dynamometer, were 76 g/km on NEDC cycle. • The use of raw biogas in CNG Vehicle has been explored. These tests have shown that raw biogas (not upgraded) can be used as a fuel, if blended with natural gas. In fact, the use of raw biogas can be envisaged in dedicated CNG engines, if new engine technologies (lean CNG combustion) are developed. In such a case natural gas can be blended with up to 70% volume of not upgraded biogas. • The potential reduction of greenhouse gases (GHG) emissions related both to the optimization of the CNG vehicle and to the use of biomethane as a vehicle fuel has been evaluated. GHG emissions from CNG vehicles (mono-fuel and hybrid) may be significantly lower than emissions of gasoline vehicles: around 17% lower in the case of dedicated CNG Vehicle and up to 51% lower in the case of hybrid CNG vehicles. In addition, biomethane (from the anaerobic digestion of waste) brings the GHG emission levels, over the course of the life cycle, down to more than 80% compared to a gasoline vehicle. Emission levels are lowered by 87% in the case of the Toyota Prius CNG Hybrid prototype fuelled by biomethane produced from waste (in comparison to a gasoline vehicle). Thus, biomethane allows a reduction of GHG emissions far below the minimum required by the European Directive on the Promotion of Renewable Energy Sources (2009/28/EC). These results have shown that the combination of optimized and innovative engines with the use of biomethane as a fuel permits to significantly reduce the GHG emissions.

Electron microscopic appearance of the liver sinusoid was examined in rats fed alcohol chronically in a complete liquid diet or in sucrose‐containing drinking water. The animals were kept on liquid diet (±alcohol) for 14 weeks or on sucrose‐containing drinking water (±alcohol) for 12.5 weeks and sacrificed thereafter. To rule out possible artifact induced by fixation procedure, livers were fixed by immersion (no perfusion), immersion preceded by perfusion, and by perfusion with glutaraldehyde and examined with both scanning and transmission electron microscopy. Regardless of the mode of its administration, and of the fixation procedure used, alcohol induced similar changes in liver sinusoid ultrastructure. Such changes included disruption of the sieve‐plate pattern of the sinusoidal endothelial cell fenestrations with the appearance of large gaps and resulting in a meshwork lining, wherein large areas of the sinusoid communicated freely with the underlying hepatocytes. Transmission electron microscopy complemented these findings. The results reported in this study demonstrate that alcohol‐induced structural changes of the liver sinusoid in the rat are similar whether alcohol is fed via a liquid diet or in drinking water. Therefore, alcohol administration in drinking water may provide a simple, inexpensive, and convenient method of inducing structural changes in the rat liver sinusoid.