Advanced Materials Research Vols. 614-615

Abstract: High-speed train air-conditioning systems put forward higher request on the aspect of air uniformity and comfort. The use of orifice which can form a more uniform velocity and temperature field in the car can be widely applied to high-speed train air-conditioning system. The experimental study of the influence of several different factors (such as the opening rate, aperture, orifice plate thickness, etc.) in the research may provide a reference for the design choices of the orifice type.

Abstract: This paper analyzed the advantages of traditional Savonius (S-type) turbine and the reasons of its low efficiency, proposed a new type of turbine with self-rotating blades and surrounded by a rectifier, and studied the aerodynamic performance by numerical simulations. The turbine is composed of a rectifier and a rotor, the rectifier consists by straight and arc segments which can accelerate the wind speed and adjust the inflow wind angle. The self-rotating blade can reduce the impacted area acting on the leeward blade by wind and arm of the impact torque, therefore reduces the resistant torque of the blade, and the driving torque acting on the windward blade is almost the same with traditional S-type turbine, which can increase the overall driving torque. The result shows that the new turbine has the advantages as below: wide range of wind speed for effective working, high power coefficient (Cp), suitable for low wind speed aera etc. Although the flow field in S-type turbine is complex separating flow, the performance of the turbine proposed in this paper is improved and is better than traditional S-type turbine in numerical simulation which is worth for spreading.

Abstract: Based on the constant speed driving mode of servo motor, analysis of capacitor energy storage device’s parameter design was made, and then a group of reasonable capacitor energy storage parameters were given. Based on the parameters, to realize variable speed driving and multi-adaptability of the press, it put emphasis on analysis of the servo driver’s control parameters and the press’s output ability. And important conclusion was also provided. To confirm the accuracy of the conclusion, the special permanent magnet AC servo system was designed and experiment was carried on it. The results prove that the designed capacitor energy storage device can satisfy the power and control request of press stamping. Analysis on control parameters of the servo driver and output ability of the press is reasonable, which provides the reference for the development of servo press’s flexibility.

Abstract: The experimental program was designed with design of experiment (DoE) technology and a series of experiments were conducted, then an approximate surface model was established with the experimental results and the significant preparation parameters of hydrous ethanol gasoline with different ethanol proportion were optimized with multi-islands genetic algorithms, then the optimal results were verified. The results show that the ethanol proportion, emulsifier type and proportion in the ethanol gasoline has a great influence on the stability; the phase separation temperature of the hydrous ethanol gasoline prepared with the optimal formula (with 25% ethanol proportion, 1.73% emulsifier S+T) is -8°C which is very close to the predicted value. The fuel can maintain stability and with no phase separate for more than 60 days in the room temperature (10°C-30°C).

Abstract: The stability and other properties of the active magnetic bearing system influenced by periodic vibration impact with the same frequency of the rotor speed are analyzed. Firstly, on the basis of the periodic displacement signal, the filtering theory of least mean square (LMS) algorithm and the deficiency of LMS algorithm in the application of AMB system, such as frequency mismatch, the relation of step-size and the frequency of displacement signal, and the mutual influence among the step-size length and frequency of the rotor and the PID controller coefficient, etc are studied. And then, a new strategy of variable step-size and real-time switching control with LMS and PID combination to filter the sinusoidal displacement signal to achieve adaptive force balance compensation is proposed. Finally, the feasibility of the new method for the adaptive compensation of the vibration of AMB system is tested by the experimental results.

Abstract: Diesel particulate filter (DPF) is one of the most effective ways to meet with diesel particulate emission control standards. In this paper, the effects of DPF structural parameters on filtration performance of different size particles are very important. On the basis of the particulate trap model of the wall flow filter, three kinds of particulate trap mechanism, such as inter trap, interception trap and diffusion trap are discussed. The influences of inlet velocity, diameter ratio and divergence angle on the distribution uniformity of velocity and filtration efficiency are also studied. The results show that reducing inlet velocity, diameter ratio and divergence angle can improve the distribution uniformity of velocity. Decreasing inlet velocity, divergence angle and increasing filter diameter can improve filtration efficiency.

Abstract: This paper introduces new type of save energy piston valve for water pump balance control, which is save energy efficiency expert. This piston valve is designed by pneumatic theory, and drive power is delivered by air compressor or pressure air source in waterworks. Pressure air is lead into cavity of piston valve by transfer action of “two positions and five channels ” electromagnetic valve, then piston drive valve to open or close water pump. This piston valve has followed functions such as balance control action, avoiding refluence, zero flow open and close, accidental power stop for water hammer and son on. Application of this piston valve had proved saving energy to 3%.

Abstract: Organic Rankine cycles (ORCs) could recover low-grade heat to useful energy. The expander is a key element in ORC systems. The expander efficiency is about 35% to 40% in the experiment. This research investigates the transient thermal-hydraulic behavior of 2-D scroll expander using computational fluid dynamics (CFD) approach. The working fluid was assumed to behave like ideal gas. The verification has been compared by mass flow rate between experiment data and CFD simulation. Finally, pitch of the scroll geometry has been selected as the parameter for sensitivity study based on the condition of no change in overall volume. The pressure-volume (P-V) behavior and volumetric efficiency with rotating speed diagram have been discussed on various scroll geometry.

Abstract: Ring gate of Ahai hydropower Station is known to the highest ring gate in the world. In this paper, it is calculated to the driving loads of the Ahai ring gate by six hydraulic servomotors during a closure without automatic control (i.e. in case of a breakdown of the electrical control system), analyzed the behavior of the operating system of the ring gate closure in balanced conditions with the permanent loads, and finally shown to how the six servomotors are synchronized on the basis of the driving loads. There are proved to The feasibility and the credibility of this system of ring gate to a case by using ANSYS.

Abstract: Cylinder deactivation (CDA) as well as valve deactivation (VDA) technologies provides big potentials to decrease fuel consumption and emission at part load operation for SI engine. In real driving situation, an internal combustion engine operates in transient operation where the load and speed varies continuously. This part load operation leads the engine to have poor fuel consumption and emission due to throttle pumping losses. This paper will investigate the further potential of both induction strategy, cylinder deactivation and valve deactivation in extending the fuel economy at part load.