Advanced Materials Research Vols. 953-954

Abstract: To study the effects of deformation on bridges, the finite element analysis method was used. The railway   continuous curved rigid frame bridge has been taken into account. Both the deadweight, prestress, and creep of the concrete were used for comparative analysis about the effect on displacement and twisting angel, then some practical application conclusions were obtained. The maximum reaction values were produced in different sections under the extreme cantilever stage and the finished bridge stage. Futhermore, the study of structural spatial behaviors is of great importance.

Abstract: This thesis focuses on the Top-down of electric vehicle promotion, conducted with Beijing as an example. First, Top-down of the electric vehicle development is gotten. By analyzing behaviors and roles of governments, enterprises and other social organizations in development, the thesis makes feasible recommendations respectively, then, based on which the thesis sums up the Top-down to promote the industry as a whole. Finally, the application of research findings in other cities is given. New ideas are given by the research findings to develop the industry, providing a great deal of inspiration to the development of the new and expanding green industry in China.

Abstract: Used a new type horizontal wave flow turbine ocean energy device as a prototype for the tank experiment, theoretically analyzed the fluid dynamics and energy capacitation of its key component turbine. Through analyzing the data of the tank experimental of the key component turbine, we found the feasibility of this kind of power device. Besides, the experiment proved a particular characteristics of the turbine of maintaining the same rotational direction whatever the directions of the incoming flow of this kind of turbine. The feature of the turbine can eliminate the complicated steering mechanism, which helped the whole device with the advantage of simple structure. The tank experiment not only provided a practical foundation for optimizing the generating device, but also gave a reference method to solve the similar engineering problems.

Abstract: To find the new type of sustainable and renewable energy and harvest energy from pavement deformation, a new idea of designing test machine to harvest piezoelectric energy from pavement is innovatively proposed. A mathematical model of open-circuit voltage is deduced from the piezoelectric equations. Design requirements of the test machine are proposed based on the model and vehicle driving condition. The construction and work principle of the machine are elaborated. A prototype of the test machine is designed and manufactured. Some experiment is done to test the excited voltage of a series of piezoelectric harvesters with the test machine. The result shows that the measured data are basically the same to the theoretical ones. It is feasible to use the test machine for measuring piezoelectric energy harvesting characteristics from pavement deformation. Therefore, the machine can be applied for in-depth and systematic studying piezoelectric harvesting energy technology from pavement deformation.

Abstract: This paper concerns the electromechanical model for a pendulum-type wave energy converter (PWEC). By introducing a based-excited mass-spring-damper, the motion of PWEC is divided into two parts: the motion of floating body and the relative motion of the pendulum and floating body. The electromechanical model involves the relative motion. Based on the electromechanical model, the circuit optimization is researched in frequency domain. The simulation results show that the device harvests plenty of power when the excitation is in close proximity to natural frequency, and the output power will decay sharply when the excitation is away from natural frequency. The optimal active power is obtained when the total reactance is zero.

Abstract: Cooling systems is significance for the structure and energy-saving operation of generator. Different cooling methods affects the efficiency and energy losing of generator. In order to quantitatively calculate the energy consumption of cooling system, this paper proposed three energy consumption indexes for large generator. Energy consuming of a dual inner water cooled generator, a water-hydrogen-hydrogen cooled generator and an evaporative cooling generator were calculated according to the proposed method. The results indicate that the total energy consumption of dual inner water cooled generator is maximum because of its low efficiency, and evaporative cooling generator effectively reduces energy consumption.

Abstract: The mathematical models of the storage refrigeration system of cold-water screw unit has been established.The operating condition of the unit and the system which working at partial load has been simulated,with different return water temperature of condenser.The influence from the return water temperature of condenser on the COP of the unit and system on the condition of different capacity of compressor has been analyzed, when the evaporation temperature is -10°C.The fact that it’s better to use start and stop operation with upload and download step by step rather than operate on the condition of low capacity of compressor, and that it’s beneficial for systemic energy conservation to use the variable frequency pump have been concluded.

Abstract: Boiler optimum efficiency problem can be solved by optimum excess air coefficient model. It is the key to find the relationship between main factors and the excess air coefficient. These main factors are smoke exhaust heat losschemistry incomplete combustion heat loss and mechanical incomplete combustion heat loss.In this paper, we projected the relationship between the factors and the excess air coefficient by using the computational formulas of principles of boiler. Then we synthesized the three formulas to establish the excess air coefficient model. Finally, this paper geted the optimum excess air coefficient using extremum method.That is αp=1.152596.

Abstract: In order to reveal the influence of thermal on the stress distribution of fiber wrapped high-pressure hydrogen vessel, the strain and stress of the vessel in pure mechanical loads are studied firstly. Then thermal loads are taken into account, and the thermal stress distribution is given out. The results show that, the stress of the vessel liner changes little when the loads differ from pure mechanical loads to thermal mechanical coupling loads. While in the fiber-wrapped layer, stresses change significantly, and are non-monotonic. In addition, the deformation of the vessel decreases under thermal mechanical coupling loads.

Abstract: Flat rectangular heliostats’ surface wind pressure distribution under resting condition was analyzed via wind tunnel experiment results. The flow field characteristics of the mirror in parallel with the ground were combined to reveal the distribution cause of fluctuating pressure. Phenomena of columnar vortex and conical vortex formed from mirror’s flow field under wind angles 0° and 45° were aimed to explain their internal structure using theory of point vortex model. With power spectrum of peculiar points’ fluctuating wind pressure analyzed, the surface vortex characteristics were further elaborated. The above work revealed heliostats’ surface wind pressure characteristics under resting conditions, and established the theoretical basis of its design study.