Advanced Materials Research Vols. 201-203

Abstract: Gas hydrate is a new energy in the 21st century with the characteristics of high energy density, huge amount of resources and cleaning. It has important significances for resources development, environmental protection and global climate changing. Due to the limitations of the occurrence mode and the technical level of marine gas hydrates, at present, the development and utilization of the resources are still tentative. This article analyzed and evaluated several key technologies to develop marine gas hydrates, that is depressurization, thermal methods, chemical injection method, CO₂ replacement method, and fluorine gas+microwave method. However, these methods are difficult to control in the mining process. The research based on the properties of the occurrence of marine gas hydrate, used the principle of gas hydrate decomposition caused by vibration, by adjusting the excitation intensity, frequency, and amplitude. Different local oscillator strength applied on the Occurrence of gas hydrate layer. Gas hydrate stable state changed in mining region, prompting the gas hydrate conversing from solid to gas. Numerical simulations show: Low-frequency vibration should be used in the layers with higher hydrate saturation. The vibration frequency should be improved in the layers with lower hydrate saturation. The method has a good controllability for the region and the process of mining, avoiding geological disasters and environmental issues in the seabed caused by the mining process losing control.

Abstract: It is an important research subject to realize safety and effective mining with the top-coal caving method in complicated geological condition. Based on the bad occurrence conditions and thick dirt band between No.8 and No.9 coal seams of Zhuxianzhuang coal mine in Huaibei mining area, the physical and mechanical properties of dirt band were analyzed, the fracture mechanism of dirt band was studied, caving laws of roof and top coal were summarized, and optimal caving technology of coal was designed and adopted. The results show that the safety and effective mining has been realized in thick seams working face of dirt band, and good economic benefit was achieved. The research results have certain guiding significance and reference value to thick seams mining under similar conditions.

Abstract: Rate capability tests showed that artificial graphite after spheroidization treatment exhibited a higher capacity in the higher C-rate region (2~10C) at a 0.1 C rate charge and variable C-rates discharge. Artificial graphite after spheroidization treatment exhibited a higher capacity in the higher C-rate region (0.5~9 C) at the same C-rate charge and discharge. These results show that artificial graphite after spheroidization treatment has a large amount of isotropic microstructures that lithium ions can intercalate into the graphene layers from all directions via edge-plane surfaces. Therefore, the artificial graphite is more suitable than natural graphite for the anode materials of high rate batteries.

Abstract: The underlying way to reduce accidents is reducing the number of workers on the coal face. Automatic mining can realize this object. The key for unmanned automatic mining is the application of electro-hydraulic control technology used on workface support. The electro-hydraulic control system applied in Wannian colliery has following function: Automatic moving , lowering and rising of support, monitoring and display of roof pressure; Shearer locating, controlling of cutting height and shearer speed, remote operation and procedure running; Automatic tension of conveyor chain, conveyor operation with constant power and monitoring and fault diagnosis of conveyor speed reducer.

Abstract: Foreign development regarding devices for speed regulating of in-pipe robot inspection has been commercially applied in gas pipeline this decade, however, the results of theoretical and structural research on bypass device were scaled in and abroad after the research of literature. First, this paper deals with the new structure of a butterfly bypass-valve, the basic parts and working principle on this speed regulating unit. The using of a butterfly disc in bypass-hole of PIG (pipeline inspection gauge) can achieve a speed regulating purpose in bypass-PIG. Next, the theoretical model of pressure loss and regulating feasibility or ability of PIG are introduced by the similar mathematical model with a throttle valve. Finally, give the conclusion.

Abstract: Sucker rod pumping is a dominated artificial lift method for oil production engineering. In the production process, diagnosing the condition of pump using dynamometer card is vitally significant to monitor and manage the pumping system. With the ability to reflect arbitrary non-linear mappings, the BP neural network can be used in pattern recognition of the pump dynamometer card. In this paper, some key technologies of establishing reasonable neural network are introduced. The number of neurons in input layer depends on the selection of characteristic value. The number of neurons in hidden layer can be obtained by some models, optimum value will be chosen out. The number of neurons in output layer depends on the recognized behavior of pump. After the construction of neural network, the more effective and practical BP neural network will be obtained by suitable samples and appropriate training strategies.

Abstract: Through researched on corrosion factors and development progress of sour gas field in China, the development situation of sour gas field in China was defined, the types of sour gas corrosion and impact factors of hydrogen sulfide stress cracking were illustrated. The results showed that, there are many corrosion mechanisms not clear when synergistic with different factors. The 105ksi grade drill-pipe was manufactured successfully, but it’s not enough for deep-well drilling. The standard API grade drill-pipe of low yield strength and hardness were mainly used in high sour gas field development. A series of tubing & casing were research and development, and applied in many overseas oil fields successfully.

Abstract: Structure composition and working principle of hydraulic driven downhole twin-screw pump are firstly introduced, and the calculation method of work and structure parameters when downhole twin-screw pump and turbine motor operate is given, and dynamic measuring process when ground power pump, turbine motor and downhole twin-screw pump coordinate is also given. The given calculation process which is derived after sufficiently considering working principle and structure features of the pump, is instructive to the design of this kind of downhole twin-screw pump, and also provides technical support for series design of hydraulic driven downhole twin-screw pump in the future.

Abstract: Helical axial multiphase pump is a new kind of pump which can pump and transport a mixture of oil, water and gas. The greatest advantage of the pump is that it can pump and transport gas and fluid at the same time, can adapt air plug and liquid slug and is insensitive to solid particle. The pump is currently drived by submersible motor. However, hydraulic drive, a new kind of drive type, is firstly put forward in this paper. This paper introduces the structure of the hydraulic helical axial multiphase pump, offers an evidence for the research development and production of the pump, deduces the calculating method of power matching of the pump and provides theory basis for the application of the new-type pump in oil exploitation in the future.

Abstract: design scheme of wind-magnetic water heater was proposed in this paper, based on the characteristics of wind energy and the principle of eddy current heating effect. Some factors affected the vortex heat power were analyzed on an equation deduction basis. A device was designed and made for verifying the effect of some factors to the temperature rising of heating plate, including rotary speed and gap between turntable and heating plate. By regression analysis, an empirical equation was derived for guiding further development of the heating system.