Advanced Materials Research Vols. 468-471

Abstract: In this paper, a basic ORC system is proposed to recover the exhaust gas energy of vehicle engines, and the mathematical model of the ORC system is built. Thirteen working fluids are analyzed. The main criterion for selecting working fluids is the mass flow rate and the heat absorption rate under the same power output of single-screw expander. Then, the paper presents an analysis of the irreversibility rate and thermal efficiency of the ORC system using 4 different organic working fluids.

Abstract: Widening of existing highway embankments can improve their capacities and ease the high traffic pressures, but it may cause a series of engineering problems including longitudinal pavement cracks, drop off or even local or global instability of embankments especially those on soft soils. How to prevent severe cracks occurring on pavement induced by widening of the existing embankments has been a great concern of geotechnical engineers. A numerical analysis by using a commercial FEM program was conducted to investigate the influence of the thickness of foundation soils on the development of transverse stress in the pavement of the existing and widened embankments. The effect of widening time on the stress was also discussed. The results indicate that compressive stress will be caused in the existing pavement prior to the widening, while considerately lager tensile stress will be induced in the existing pavement after widening. In the view of reducing pavement tensile stress, a most suitable time to begin widening was proposed for engineering practice.

Abstract: Flow meter coefficient calibration system is designed and developed by the software of LabVIEW, hardware of PCI-6601 and USB-6008 from NI. Synchronous dual timer pulse interpolation is used to increase the calibration accuration of Standard flow meter method.It’s also necessary for system to collect the real-time temperature and pressure parameters to correct gas volume. The software complied by LabVIEW realizes functions of manage and data processing, the calculation and Storage of data, inverter control, report, data playback, and interactive interface. Results of experiments show that: compared to the routine standard flow meter method, the System has the more calibration accuracy and the less work time.

Abstract: Aiming at implementing numeralization, automatization and imaging of ultrasonic testing in rotary parts used in coal mine machinery, ultrasonic P-scan imaging technology of rotary parts is studied in this paper. Searching pixel units according to the incident direction of ultrasonic, and correcting non-isotropic resolution images to isotropic ones with linear interpolation algorithm to, multi-layer B-/C-/D-scan and 3-D projection view imaging are achieved. Experimental results show P-scan image could accurately reflect the localization, quantification and orientation of flaws.