Advanced Materials Research Vols. 753-755

Abstract: This paper gives a solution of prepayment and software design in the intelligent electric meter. Firstly introduces the development and the future trend of the meter, the overall design scheme is given, a software platform built. Then the design of the CPU IC card circuit, IC card processing program, and the main program, real-time power program and electricity consumption measurement program are also designed. System uses LPC2290 as the main control chip, using ADI company ADE7755 electric energy metering chip, the software uses the modular design, not only can realize the measurement of electric energy, but also can accomplish the communication with the host computer, easy to build energy platform for energy management and control etc.

Abstract: By analyzing the structural thermal load mechanism of boiler drum, several temperature field models were analyzed and compared; thermal stress calculation method and its impact on the overall stress field were studied. Finally, according to the domestic and several foreign fatigue life assessment standards, the fatigue life prediction modes of boiler drum were discussed. Based on fatigue curve interpolation and the Miner fatigue linear accumulated damage theory of safety guidelines, the life loss results of initiating low-cycle fatigue crack can be calculated. Both ASME code and GB/T9222-2008 standard are suitable to fatigue life assessment for boiler drum, due to the reasonable basis and reliable results.

Abstract: The hydraulic cylinder should be safety released in high-pressure situations, the release valve system is presented under such situation in this paper, which can release the high pressure from the hydraulic cylinder, in order to validate its feasibility, the simulation model of pressure release system is established in AMESim, the pressure release process of which is studied, the results show that the pressure relief system can release the high pressure of hydraulic cylinder smoothly, the pressure release system verifies the pressure control performance of control system, some of the parameters or factors of pressure release system are analyzed.

Abstract: The mathematical model of gas-solid flow 2D fluidized bed was established. The CFD simulation was carried out with commercial software FLUENT6.3 by using Eulerian-Eulerian multiphase models, based on the kinetic theory of granular flow and PC-SIMPLE algorithm. In order to provide a basis on optimizing the operating conditions of the fluidized bed applied in benzene series organosilicon reactor, the processes of bubble formation, growth and disappearance under different cases were analyzed.

Abstract: Based on a heat pump system of mechanical vapor recompression (MVR) designed and manufactured independently, the heat transfer performance of falling-film evaporator was measured by a combination way of theory analysis and experiment proving as the heat pump operated in practice. After the result of theoretical calculation is worked out, the start thickness and entrance velocity of the liquid film are established by adjusting the flux of raw solution. The result shows there is an optimization that the film thickness at the bottom of the tubes amounts to that of boundary layer of velocity. Additionally, it is a process of falling-film flow with heat and mass transfer between the start and end of falling-film. The last thickness of the falling film is about 0.21~0.44mm. The thickness of falling film when the falling-film flowed and heat exchange was over is compared with each other, and the effect of heat resistance on heat transfer is discussed also. It is showed that an optimal thickness is formed during the process of falling-film flow and evaporation, and disadvantages come up when it is not formed. The falling-film evaporator propelled by the MVR heat pump with low compression ratio carries through a process of strong and high-efficiency heat transfer with phase transition. It is because the states of produced vapor both before compressed and after compressed are saturated. Its heat-transfer coefficient may be as high as 1990 W/ (m²·K). The start and end thickness of falling film become great while the evaporation pressure goes up. It leads to the drop of the heat-transfer efficiency, so there is an optimization to the system in all probability.

Abstract: Based on the situation that the hydraulic position servo system is easily influenced by the external interference and the parameters of which are different with time-varying, the fuzzy control can soften the buffeting and the sliding algorithm has no the same problems as the hydraulic position servo system, a brandly-new fuzzy sliding control algorithm is designed. In the simulation process, within the parameters of simulated time-varying and outside strong interference, the results show that the hydraulic servo system based on fuzzy sliding mode control algorithm has a greater resistance to internal and external interference and time-varying parameters.

Abstract: With increasing of high pressure, the performances of all kinds refrigerants except for R744 are all declined and transcritical R744 compression cycle has an optimum high pressure. With increasing of the evaporating temperature, all cycle COP is an increasing trend, with increasing of outlet temperature of condenser, the performances of all cycles are decreased. Under the same comparison conditions, the performance of R134a refrigerant cycle is superior to the cycles of other refrigerants, and the cycle of R11 refrigerant has the worst performance.

Abstract: In order to study the influence of heel on bubble layer shape and stability, based on Fluent and Mixture model, a numerical model was established to calculate bubble layer shape at the plate bottom at different main flow velocity, air flow rate and heel degree. The influence on bubble layer shape and skin friction reduction rate caused by heel was investigated. The results show that: bubble layer at the plate bottom spreads with the inflow transversely and longitudinally. When there is heel degree, bubble layer drifts to the smaller draft side. As heel degree increases, the drift of bubble layer becomes larger and the skin friction reduction rate decreases greatly. The local skin friction even increases greatly at the plate bottom apart from the air injection board. Both local void ratio and local friction reduction rate decreases in the longitudinal direction along the plate. Local void ratio is bigger than local friction reduction rate and the difference increases in the longitudinal direction along the plate.

Abstract: Downhole Gas Compression (DGC) is an entirely new powered artificial lift technology specifically for natural gas wells. The technology offers the opportunity to increase production by 30-50%, significantly improve reserves and delay the onset of liquid loading. Key application of DGC is for use in deeper partially depleted reservoir wells encountering liquid loading. The research progress of DGC is introduced in this paper and the results of theoretical and experimental study of DGC are investigated. Moreover, the adaptability and application prospect of this new technology is analyzed. There are many gas fields in China faced with problems about effective drainage and recovery enhancement, such as the mature gas fields in Sichuan and Ordos Basin. DGC will have a good application prospect in China and further study of the DGC technology is recommended.

Abstract: This study presents the static and dynamic characteristics of load-sensing and pressure-compensated directional control valve under the working conditions. A mathematical model is developed, two types of working conditions are presented through the static work point calculation. The static characteristic is analyzed by simulation, and the conclusion is validated by experiments. Solution procedure of the flow gain transfer function and flow-pressure coefficient transfer function is detailed introduced based on the above static computation, and their dynamic characteristic is analyzed by using Bode diagram. Finally, three types of compensatory modes are proposed, which provides very useful value and significance for the hydraulic component or system design and parameters optimization.