[en] A series of experiments have been performed in a vertical tube of 9.4 mm inner diameter using the Freon, HFC-134a as working fluid medium under the supercritical pressure range. Two kinds of experiments, i.e. steady-state and pressure transient, have been carried out. As for the steady-state heat transfer experiment, the mass flux was in the range between 600 and 2000 kg/m2s and the maximum heat flux was 160 kW/m2. The selected pressures were 4.1, 4.3 and 4.5 MPa which correspond to 1.01, 1.06 and 1.11 times the critical pressure, respectively. In the pressure transient experiments, the inlet pressures were varied from 3.8 to 4.5 MPa and vice versa in the pressure transient simulations. In this study, heat transfer correlation and criterion for the heat transfer deterioration are suggested under the supercritical pressures. And also heat transfer characteristics during the pressure transient are examined

[en] Ions produced by crossed-beam collisions of pulsed monoenergetic electrons and supersonic expansion molecules have been analysed by time-of-flight mass spectroscopy (TOF-MS) in order to determine the appearance potentials, absolute total, dissociative and parent ionization cross sections and nascent ion kinetic energy distributions. The electron impact study was conducted at incident electron energies up to 100 eV on the parent CH₂F₂ molecule (and Ar/CH₂F₂ mixtures), a fluoromethane where the CH₂F⁺ ion is produced at higher yields (1:18) than the parent molecule ion, CH₂F₂⁺. TOF-MS band profiles analysis has enabled us to determine the ions' nascent kinetic energy distributions, information that combined with the dissociative ionization appearance potentials, calculated molecular orbital energies and orbital bond characters, leads to improved identification of the electron impact dissociative channels. (author)

[en] To understand heat transfer mechanism from general character and make clear the difference caused by properties, experiments of heat transfer to water and Freon R134a flowing upward in vertical tubes were conducted on SWAMUP and SMOTH test facilities, respectively. The variations of heat transfer coefficients of water and Freon with dimensionless temperature are coincident in the case of normal heat transfer, heat transfer enhancement and heat transfer deterioration due to buoyancy force and acceleration effect. The HTC ratio decreases with the increase of dimensionless parameter π_B. The HTC ratio increases first and then decreases with the increase of dimensionless parameters π_A. The dimensionless parameters π_B and π_A show better relevance on the supercritical water and Freon experimental data, respectively. The investigation of the heat transfer behavior of supercritical water in the SCWRs by means of model fluid Freon R134a is proved reasonable and feasible because of the similarity dependence on dimensionless parameters. (authors)

[en] Initial energy audit has been conducted in the framework of energy saving program in PSTBM - BATAN, from the result of initial energy audit of electric energy consumption one month is worth 41.871.27 kWh. With the target of Energy Consumption Intensity of PSTBM Building obtained at 13.56 kWh/m², the achievement target of IKE is categorized as efficient (8.5 - 14 kWh/m²) pursuant to Regulation of Minister of Energy and Mineral Resources, 13 in 2012, and quite efficient (12.08 - 14.58 kWh/m²) based on IKE Criteria Standard building based on the Ministry of National Education Year 2004. The initial energy audit was conducted in February 2017 by collecting historical data and then conducting a direct energy audit on all buildings in PSTBM. After completion, the data obtained were analyzed and then it was concluded that 40 buildings consumed most electricity at 29,990.78 kWh/month or about 73 %, and 41 buildings consumed at least 586.85 kWh/month or about 1 %. Electrical cooling from air conditioners is 74 % of most sectors in total, it is necessary to modify the cooling room with the latest AC technology using R410 type freon gas. The recommendation of this initial energy audit program is to carry out a detailed energy audit that will produce energy saving recommendations electricity. (author)

[en] Experiments on Critical Heat Flux (CHF) of Freon-12 have been carried out in the rectangular vertical channels with gap sizes of 1 mm, 2 mm, and 3 mm, respectively. Analysis of CHF data in the different channels shows that CHF decreases as the increase of pressure, and while the exit quality rises, CHF falls down quickly. Meanwhile, CHF goes up as the mass velocity increases when the exit quality is lower, and contrarily, when the exit quality is higher, the increase of mass velocity results in the decrease of CHF. According to the analysis results, a conclusion can be drawn that gap sizes almost have no effect on the CHF in rectangular channels with gaps from 1 mm to 3 mm under the same condition in the experiment. (authors)

[en] A novel method of measuring the rate of nucleation of superheated drops and also the lifetime of metastable superheated drops accurately has been developed. The lifetime of superheated drops of Freon-12 has been determined by measuring the time dependence of the volume of vapour formed due to spontaneous nucleation of the drops using a relative water manometer. The time dependence of the nucleated volume of vapour indicates the presence of two lifetimes of decay of superheated droplets by spontaneous nucleation

No abstract available

[en] This annual technical progress report is for part of Task 4 (site evaluation), Task 5 (2D seismic design, acquisition, and processing), and Task 6 (2D seismic reflection, interpretation, and AVO analysis) on DOE contact number DE-AR26-98FT40369. The project had planned one additional deployment to another site other than Savannah River Site (SRS) or DOE Hanford Site. After the SUBCON midyear review in Albuquerque, NM, it was decided that two additional deployments would be performed. The first deployment is to test the feasibility of using non-invasive seismic reflection and AVO analysis as a monitoring tool to assist in determining the effectiveness of Dynamic Underground Stripping (DUS) in removal of DNAPL. The second deployment is to the Department of Defense (DOD) Charleston Naval Weapons Station Solid Waste Management Unit 12 (SWMU-12), Charleston, SC to further test the technique to detect high concentrations of DNAPL. The Charleston Naval Weapons Station SWMU-12 site was selected in consultation with National Energy Technology Laboratory (NETL) and DOD Naval Facilities Engineering Command Southern Division (NAVFAC) personnel. Based upon the review of existing data and due to the shallow target depth, the project team collected three Vertical Seismic Profiles (VSP) and an experimental P-wave seismic reflection line. After preliminary data analysis of the VSP data and the experimental reflection line data, it was decided to proceed with Task 5 and Task 6. Three high resolution P-wave reflection profiles were collected with two objectives; (1) design the reflection survey to image a target depth of 20 feet below land surface to assist in determining the geologic controls on the DNAPL plume geometry, and (2) apply AVO analysis to the seismic data to locate the zone of high concentration of DNAPL. Based upon the results of the data processing and interpretation of the seismic data, the project team was able to map the channel that is controlling the DNAPL plume geometry. The AVO analysis located a major amplitude anomaly, which was tested using a Geoprobe(trademark) direct push system. The Geoprobe(trademark) was equipped with a membrane interface probe (MIP) that was interfaced with a sorbent trap/gas chromatograph (GC) system. Both the Photo Ionization Detector (PID) and Electron Capture Detector (ECD) on the GC exceeded the maximum measurement values through the anomaly. A well was installed to collect a water sample. The concentration of chlorinated solvents in the water sample was in excess of 500 ppm. Other amplitude anomalies located directly under an asphalt road were also tested. Both the PID and ECD were zero. It appears that editing of poor quality near-offset traces during data processing caused these anomalies. Not having the full range of source to receiver offset traces in those areas resulted in a false anomaly during AVO analysis. This phenomenon was also observed at the beginning and end of each seismic profile also for the same reason. Based upon the water samples and MIP probes, it appears that surface seismic and AVO analysis were able to detect the area of highest concentration of DNAPL

[en] CHF experiment is carried out in φ20x2.5 tube on the Freon-12 thermal hydraulic facility in order to assess the CHF Fluid-to-fluid scaling technique. Based on different databases, the compensated distortion model of Ahmad, Lu Zhongqi model, Groeneveld model and the empirical scaling model of Stevens-Kirby are compared on the aspect of predication precision and applicable range. It is the fundament for the experimental study of CHF Fluid-to-fluid scaling technique in complex channel

[en] Experiments were conducted at supercritical pressures and temperatures on a vertically-oriented annular heating rod with a wire-wrap spacer using upward-flowing R134a to determine the effect of a wire-wrap spacer on heat transfer in proximity of the pseudocritical point. Measurements were taken at quasi-steady-state and pressure-transient conditions. During each instance of deteriorated heat transfer, the Nusselt number is greater than values predicted by the Dittus-Boelter correlation. Heat transfer during the pressure transients is observed to be insensitive to the time rate of change of the fluid pressure, which implies that the transience does not affect the instantaneous state of the heat-transfer process. (author)