The Key Parameters Method of Calculating Geothermal Heat Exchanger Length

The geothermal heat exchanger is the key component of ground coupled heat pump systems. We discuss the key parameters method of calculating geothermal heat exchanger length based on line source theory. Typical meteorological year data is used to determine the hottest month, the coldest month and annual average surface temperature. The building hourly load can be obtained by introducing the concept of equilibrium temperature. The cooling fraction and the heating fraction then can be calculated using building hourly load and performance parameters curve fit of a water source heat pump unit. The method for selecting the hottest and lowest entering fluid temperature and calculating the borehole and ground thermal resistance is given. A vertical U tube heat exchanger length calculation procedure is proposed.     

Congestion Management Analysis Based on Flow Gate Rights

In order to alleviate the congestion economically and effectually under the competitive circumstance of electricity market,an applied method of congestion management,which based on FGR(Flow Gate Rights),has been proposed.The share of line has been used to define the power plant's influence on congestion.The proportional principle has been used to compute local marginal price.Then they are both used to balance the charge of FGR.The ISO(Independent System Operator) will dispatch the system to meet the FGR holders' rights.This method is used to alleviate congestion effectually,activate power plants to take part in scheduling positively,and level off the price.An instance is used to illustrate the feasibility of this method with FGR.     

Influence of Soft Soil Layer on Dynamic Characteristic of the Slope

The dynamic finite element method is used to analyzes the influence on dynamic characteristic of the slope by soft soil layer. The parameters which influencing the earthquake response of the slope, including the depth, the thickness, the obliquity of soft soil layer are analyzed. The influence of soft soil layer is obvious, which must be thought over in the analysis of slope stability. The thicker the soft soil layer is, the more obvious the filter and the amplitude effect is. The deeper the soft soil layer is, the more obvious the filter effect is. The filter effect of the obliquity of the soft soil layer to dynamic time history is not obvious.     

Study on Consolidation of Reinforced Soft Foundationwith Two-way Drainage of Sand Well

Based on traditional consolidation theory, the soft ground settlement is calculated and one-, two-, and three-dimensional consolidation of reinforced soft foundation with sand drain is studied. The calculation method of average sand drain and the new modified method are discussed. The results can serve as a guide to subgrade design of soft ground.     

Experiments on cleaning tunnels with dry ice

Vehicle exhaust,dust and grease in tunnels are hard to be degraded,thus there will be more and more pollutants and the traffic safety will be influenced. Therefore,regularly cleaning tunnels is important for guaranteeing the traffic safety in tunnels. A tunnel cleaning method with dry ice is proposed,and a model of dry ice cleaning tunnel is developed based on the physical,chemical and cleaning properties of dry ice. Some experiments about the surface hole,surface temperature and the uniaxial compressive strength of the concrete are conducted. The surface damage and the compressive strength of the concrete is researched after the cleaning process. The test results show that：the dry ice cleaning method can thoroughly clean the surface of concrete;the surface damage and the compressive strength is little influence by the temperature and dry ice micro blasting. So dry ice cleaning method can be used for cleaning tunnel.     

Analysis on the Quasi Monte-Carlo Method and its Application in the Slope Reliability

The critical reliability slip surface with minimum value of reliability index is difficult to be obtained by the Monte-Carlo method. The simplified Bishop method was adopted to calculate the factor of safety for given circular slip surface thereby defining the performance function in reliability analysis. Six variance values of random variables were designed and four sample ranges were assumed. A quasi-Monte Carlo method was defined with fow samples. One hundred and thirty-two potential slip surfaces were randomly generated. The reliability indexes regarding those slip surfaces were calculated by Monte-Carlo method and quasi-Monte Carlo method, respectively. The comparative results show that in the case of one random variable, the reliability index from Monte Carlo method is found to be linear with that from quasi-Monte Carlo method. In the similar conditions, the wider the sample range, the smaller the tangent value of line, and Vice versa. In addition, the bigger the sample number, the bigger the tangent value of line. The Quasi-Monte Carlo method is approved to be practicable for the determination of critical reliability slip surface for homogeneous slope.     

Optimization of quenching parameters for ultra high strength steel using response surface method

In order to optimize the quenching parameters of ultra high strength steel 22MnB5,orthogonal experimental design method is applied to design the experiments and response surface methodology (RSM) is used to analyze the experimental results. Austenitizing temperature and soaking time are taken as the optimization factors. The effect of these factors on quenching hardness and elongation are investigated. The optimization results of each single objective are firstly obtained. Then,ideal point method is used to find the solution to the multi-objective programming,and global optimums are gained. Finally,the optimal results are discussed from the microstructure angle and the reliability of the prediction models is demonstrated.     

Analysis on the method of selecting nodes on the erosion diagnosisof grounding grid

The number of underdetermined equation, which is limited by the grounding down lines, reduces the grounding grid corrosion diagnostic precision. Based on the grounding grid fault diagnosis method and sensitivity analysis, the value of slip resistance change on the impact of the port resistance in several cases, such as small span, large span and edge, center and symmetrical cross line of the grounding grid, is analyzed. A new method which is used to select the node pairs to calculate the corrosion situation of grounding grid is presented. Based on this method, the simulation analysis and field test has been done. The experimental results show that this method could improve the accuracy and efficiency of grounding grid fault diagnosis.     

Key parameters analysis of surface subsidence induced by tunneling construction

In order to identify the key factors inducing the surface subsidence while shield tunneling，a key parameter selection model and solving method based on RS-SVM is proposed. The information entropy rules were used to discretize seven continuous variables including Internal Friction Angle(IFA)，Cohesive Force(CF)etc. Genetic Algorithm and Rough Set for attribute reduction were combined to obtain several collections that significantly affect the surface subsidence; Using the statistical learning of RVM to select the best collection which optimally reflects the relationship between parameters and surface subsidence，we get four parameters: Single Ring Grouting Pressure，Internal Friction Angle，Specific Torque(ST)，Incision of Slurry Pressure and each of the collections was the critical parameter that should be considered in construction. The method was applied in a completed metro tunnel in Wuhan，China and the results indicated the feasibility of the method.     

Grinding teeth temperature analysis of large flat wheel

At present,there are many planar workpiece grinding thermal models. However,they cannot be applied to the calculation of the tooth-like surface grinding. Therefore,based on the gear involute arc fitting,the moving heat source method and the imaging method are combined in this work to deduce the analytical thermal model of grinding teeth with large flat wheel,which can be used to calculate the temperature of grinding gears. The simulation of grinding process is made based on ANSYS and compare to the established quasi-steady-state analytical thermal model. The comparison results show that the value of grinding temperature predicted by numerical model has well agreement with the analytical model and some errors exist in the contact area and the junction between contact area and non-contact area. The deduced analytical thermal model can be used to analyze the temperature of processing tooth-like curve workpiece.     

Technique of Surface Reconstruction for Three Dimensional Structure of Chinese Medicihnal Materials

To study the technique of surface reconstruction for Chinese medicinal materials from its cross-sectional images and to display its three dimensional structure.The pattern recognition technique is used to complete the classification and matching of various structures, then the triangle surface approximation is used to produce the 3D surface of the structure.The 3D structure is reconstructed and can be viewed by flexible way based on SGI workstation. The technique and method provided by this paper is contributive to the study and view of various structure of Chinese medicinal materials, and is available to biomedical image processing field.     

contact stress and steady thermal analysis of herringbone gears in a gas turbine

To obtain the distribution characteristic of contact stress and the bulk temperature on the surface of herringbone gears, parameter modeling of gears was carried out by parametric design language. A numerical simulation was given to calculate the contact stress field and the steady thermal field by combining heat transfer theory, tribology theory, and mesh theory. The distribution of contact stress, the bulk temperature and heat flux also were analyzed. The analysis results show that the distribution of the load along the contact line possesses regularity. The heat flux along the tooth depth direction decreases first and then increases. The effect of thermal conduction of the tooth is stronger than that of convective heat transfer. The conclusion indicates that the finite element emulation method can be used to estimate the transmission performance of herringbone gears.     

Degital Simulation for the Direct Torque Control of Induction Motors Using the Circle Flux Path

This paper introduces the importance of developing the Ground-Source Heat pump and describes the prospects of it.with the method used abroad to acquire the temperature profiles within surrounding soil of the underground heat exchanger with buried tubes, in this paper the line heat source theory and thermal resistance network analysis method were used to set up the heat transfer model.The original temperature of the ground is determined by calculation and is compared with test results. Experiments of running single tube and running three series connection tubes are carried out on the built underground exchangers of vertical buried tube type.And the data which can provide reference for the Ground-Soure Heat pump technique are acquired.     

Color Lapse by Halo Retreat for Night Landscape Lighting

This paper focused on making use of color change to incarnate hierarchy of floodlighting of the building facade in landscape lighting. Color lapse by halo retreat is a good method to reach this goal. The projection light source was chosen on the principle of building exterior color coordination. According to the computing method for chroma coordinates of object color, the magnitude of three stimulus values after reflection by external wall surface and the chroma coordinates were calculated. The purpose of this paper is to take account of the influence of difference between projecting light and reflecting light on external wall surface. At the same time, an approximating computing method is recommended, that is, first figure out the chroma coordinates of two points--the top and bottom points in vertical line of the building and then readjust the location of casting light lamp and lighting fitting or renewal the light source. Then let the chroma coordinate of ever point on the vertical line settle in or be near the line connecting the two points of chroma coordinates on CIE 1931 Chroma chart. It would yield good results due to the color lapse by halo retreat.     

Development and experiments of direct resistance heating in hot forging

A new hot-forging method by means of direct resistance heating is investigated aiming at the long produce time and large energy consumption of traditional hot forging. The hot upsetting experiments with cylindrical billet of 42CrMo4 are performed. The influences of initial contact force, surface quality of the billet and current intensity on the heating temperature are researched. The results of the experiments show that the billet can be heated quickly to forming temperature by the approach. The relatively low initial contact force is useful to increase the heating temperature. The heating temperature is proportional to the square of the current intensity, and the heating temperature is seriously affected by the surface quality. During the forming process the billet cooling rate is effectively decreased and the forming time is extended in relation to the resistance heating.     

The on line monitoring method of power transmission line fault basednon linear frequency response function

A novel method for power transmission line monitoring and fault diagnosis is proposed based on non linear frequency response analysis. The power line carrier signal has been used for on line monitoring of power transmission line. As the non linear frequency response function describes the system inherent characterization, different frequency response patterns corresponding to different operation states of transmission line can be established. Based on the analysis of transmission line characteristics of fault modes, various fault features can be extracted, thereby achieve online monitoring and fault diagnosis on transmission line. Simulation experiments show the effectiveness of the proposed method.     

Heat Conduction due to Moving Heat Sources in Semi infinite Body

Combined image method with heat source function method,heat conduction due to moving heat sources is analysed in semi infinite body and cylinder with heat exchanging on its surface.The distribution of temperature is obtained when the wall temperature is constant and the wall heat flux is zero.The result is useful for engineering calculation.     

Denoise Based On Translation Invariance Wavelet TransformAnd Its Applications

De_noising algorithm based on traditional wavelet transform may produce artifacts on discontinuities of the signal. The reason is that the de_noising algorithm lacks of wavelet translation invariant. This paper proposes a de_noising method based on translation invariant. The method performs the cycle_spinning for the signal to be analyzed. And then, the soft (hard) thresholding is used to shrink the wavelet coefficient of the signal and reconstruct the signal. Consequently, the shift dependence of wavelet basis is eliminated. This method can suppress the artifacts effectively so that de_noised signal is more smooth and has better approximation to original signal.     

Analysis of a multimode transmission line model of the shielding effectiveness of enclosures with apertures

The equivalent transmission line method is extended to multi-transverse electric modes of cavity which are introduced by aperture coupling, and it is used to analyze the shielding effectiveness of rectangular enclosures with apertures. The multimode transmission line method is verified by HFSS(High Frequency Structure Simulator). The results show that higher-order mode is essential to obtain an accurate shielding effectiveness of rectangular enclosure on wide frequency domain. Below the frequency of 1 GHz, nearer to the slot, the impact of higher-order mode on the shielding effectiveness is greater in the place mear the slot. Higher-order mode leads to a better shielding effectiveness.     

An optimization method for the nozzle arrangement in secondary cooling zone of continuous casting

Based on the existing research on nozzle arrangement method in secondary cooling zone of continuous casting, the method of superposed water flow density is put forward to optimize the nozzle arrangement at casting direction and transverse section of slab according to the optimization principle. The two-dimension heat transfer model is established. The solidification morphology of cross-section at casting direction is simulated with consideration of the influence of water flow density inhomogeneity on solidification process at transversal section, and the temperature distribution of slab, solidification process, and quality of slab are compared between before and after optimization. The results indicate that the surface temperature of slab is dropped equably after optimization, and the casting blank is cooling uniformly in the water springing zone so as to ensure better quality of the casting blank.