Advanced Materials Research Vols. 516-517

Abstract: Due to great loss of energy consumption and too high temperature of exhaust in Circulating Fluidized Bed Boiler, the paper investigates how to optimize and modify the primary air system. Changing the traditional way of modulating the position of adjustable plate to regulating the speed of electrical machine by frequency converter, the amount of primary air and pressure is reduced and the goal of energy-saving and consumption-decreasing is achieved.

Abstract: The numerical simulation in the classification has been used in ANSYS CFX 10.0. We described the different flow fields within the classification in accordance with the one-phase simulation experiment, which provided a new theoretical perspective for optimized design on classification. At the same time, the classification efficiency was predicted by simulation for two phase particle trajectory. This will lay a foundation for improving classification efficiency.

Abstract: Inducting dissolution speed constant and multistage reaction series to the alkaline solution transmission equation, this article established the alkaline solution transmission equation with multistage reaction dynamics in the porous media of stratum mineral and calculated one-dimensional alkaline solution concentration distribution. Experimental results verified the correctness of transmission equation, moreover, it further analyzed the alkaline solution regularity in the porous media. The model will be used to predict alkali loss, optimize alkaline solution concentration and slug size, thereby alkaline waterflooding or combination drive can obtain better displacement characteristics and improve the oil recovery.

Abstract: First this paper analyzes the model structure and the output characteristics of the photovoltaic (PV) module, and then we get the output characteristic curve using the parameter sheet. In this paper a simple, quick, and low cost Double-line MPPT ( maximum power point tracking) method and an simple temperature compensation method are proposed after analyzing and comparing the cell’s output features in terms of irradiance and temperature environment changes .The detailed process of the theoretical derivation and the simulation in MATLAB are provided. At last, the paper introduces the control strategy of the Double-line MPPT method. We conclude that Double-line MPPT method is Low-Complexity, easier to realize , faster without oscillation compared with other methods ,it can be used in low power PV system.

Abstract: This paper represents particularity and importance of pumped-storage power station unit. It introduces localization governor hydraulic system’s composition, difficulty point and key point of 300MW class pumped-storage unit. It also puts forward pump direction and turbine direction dual rate closing program to active and introduces application status on side.

Abstract: The dynamic behavior of small particles in fixed spaces is of interest in various fields of science and engineering. In the paper, a population balance equation for particles in fixed space is established to describe the dynamic behavior of system involving simultaneous coagulation, diffusion deposition, gravity sedimentation and ventilation. Related Parameters are decided by experiments for the convenience of achieving numerical solution of the equation. Finally, the temporal evolution of particles population in fixed space is simulated and discussed under different conditions.

Abstract: Based on a transient analysis code that developed with coupled neutron and thermal hydraulic calculation model for supercritical water reactor, the transient characteristics under feed-water parameter changing is detailed analyzed, including temperature decreasing, flow-rate decreasing and pressure increasing. The results show that, if no control system action given, flow rate or temperature decreasing would lead to the increase of main steam temperature and decrease of core power, but pressure increasing shows a little influence. If control systems are put into operation, transient characteristics will be obviously changed but finally recovered to normal level. As the same changing percentage 3% is selected, main steam temperature during pressure decreasing transient can reach its highest level in 510.9°C, and return to normal at the time of 90s. But for feed-water temperature decreasing transient, main steam temperature shows an obvious fluctuation during its adjustment and returns to normal until 170s from 503°C. In addition, compared with the results calculated by non-coupling calculation model, main steam temperature calculated by above coupling model shows a smaller deviation but a little longer time needed for returning to its normal value.

Abstract: The shortage of control system for the air-cooling unit is the lack of theoretical guidance and relative operating experience in the selection of operating mode. The mathematical model is built to optimize the initial steam pressure of the air-cooling unit with the method of systemic analysis. Through calculation of air-cooling unit NZK600-16.7/537/537-Ⅰ, the optimal initial steam pressure curves in different work conditions are obtained. The analysis will improve the optimal system-wide control theory of air-cooling power plant. Limitation of the initial steam pressure curve provided by manufactory is also analyzed in this paper.

Abstract: Aiming to the key demands of cost, service life, environment and the time of energy storage in the energy storage technology of the distributed power generation of renewable resources, a novel compressed air green storage device based on the hydro-pneumatic conversion is put forward on the base of thermodynamics foundational principles. By the theoretical analysis for the energy cycle process of the storage device proposed, the corresponding calculation formulae are deduced for the energy storage efficiency and density under the condition of ideal gas, respectively. In addition, the changes of above index with pressure, compression ratio, and isentropic exponent are also researched. And the results show that the energy storage efficiency and density can be improved efficiently by controlling the energy conversion under the near isothermal condition so as to enhance the heat exchange capacity between the given energy storage device and its surrounding environment.

Abstract: The injecting online leak sealing technology is an emergency repair technique widely applied in process industry, which can remove the leakages of the devices, flanges, pipes and valves, with safe, reliable, economic and efficient. In a variety of online leak sealing operations, the work to handle flange leakages accounts for about 90% of the entire workload. This is because most of flanges in actual production have the installing and machining defects, such as uneven clearance, eccentric, reducing, etc. Aimed at those flanges with defects, to ensure the seal effect, the online leak sealing clamp must be machined and installed precisely, which will increase the difficulty of operation. Thus, on the basis of comparing advantages and disadvantages of the existing enhanced seal clamps, a new design has proposed to solve the problem of flange leakage, especially for the flange with defects, which can reduce the difficulties of operation while ensuring the sealing effect.