34 results about "Compressibility factor" patented technology

A system achieving a high density of transported natural gas by compressing it to high pressures typically above 5 MPa to transport the gas in a modified composition that permits a very low compressibility factor at near ambient temperature either above or below. This reduces greatly the size of the cooling systems that are required. In some cases cooling of the compressed gas may be achieved in a simple heat exchanger cooled by air or water. The transport of the gas takes place in self propelled ships or non-self propelled barges fitted with a cargo containment system capable of storing the cargo at high pressures, typically above 5 MPa and usually not above 25 MPa. The transport vessel may carry a store of higher molecular weight gases (c2 through c7) that when mixed with the incoming cargo results in a molecular weight of the mixture of at least 22 and possibly as high as 28 or higher. The store of higher molecular weight cargo may be gained from gases that condense during discharge of the vessel at its destination due to the adiabatic cooling of the cargo during discharge. These liquids may be retained aboard and transported back to the origin. If insufficient quantities of heavy gases are available at the origin they may be loaded at the destination. If required, the composition of the heavy gases transported back to the origin may be changed through partial discharge or partial receipt of additional hydrocarbons or a combination thereof at the destination point.

The invention provides a BP neural network digital image compression based image watermark embedding and extracting method. The method includes: S1a, performing scrambling treatment on an original watermark image to acquire the scrambled watermark image; S2a, establishing a BP neural network and setting transfer function, training adjustment function, the number of training, neuron activation function thresholds, learning constant and compressibility factors of the BP neural network; S3a, dividing the scrambled watermark image into image embedding blocks, setting input and output expectations as carrier image blocks, and training the carrier image blocks through the BP neural network to acquire output O of a hidden layer; S4a, embedding watermarks in the output O of the hidden layer, and decompressing compressed images embedded with watermark image information to obtain carrier images embedded with the watermarks. The invention further provides a BP neural network digital image compression based image watermark extracting method.

The invention discloses a data compression, transmission, receiving and uncompressing method and a corresponding device, can achieve IQ data compression with low complexity and small error, and can achieve transmission of IQ data compressibility factors with fewer resources. The data compression method comprises reading data to be compressed, finding I data and Q data with maximum absolute values from a group of data to be compressed, determining an effective bit number M of the I data with the maximum absolute value and an effective bit number N of the Q data with the maximum absolute value, generating a first digital automatic gain control (DAGC) factor for compressing the I data according to the effective bit number M and a compressed target bit wide number X, generating a second DAGC factor for compressing the Q data according to the effective bit number N and the compressed target bit wide number X, using the first DAGC factor to compress each I datum in the group of data to be compressed, and using the DAGC factor to compress each Q datum in the group of data to be compressed.

The invention discloses a parameter optimization method considering inverter stability under a weak power grid for an LCL filter. The method comprises the following steps of S1, building an inverter grid-connected output impedance model; S2, analyzing influence of power grid impedance on stability of an inverter grid-connected system; S3, building a multi-target LCL filter parameter optimization model considering power grid impedance influence; S4, solving the optimization model by employing an improved compressibility factor method-based particle swarm optimization algorithm; and S5, optimizing the LCL filter parameter. The optimization model is suitably used for designing the LCL filter parameter under the weak power grid or a multi-inverter intensive connection condition, standard satisfaction is introduced into an estimation index, the optimization degree is quantitatively evaluated, much-aspect indexes such as filtering performance and economic cost can be compatible very well, and integral optimization on LCL filter and current ring parameters is achieved; and by the method, theoretical basis is provided for stability analysis of inverter intensive connection under a new energy station, and guidance is provided for designing the grid-connected inverter parameter under the weak power grid.

This invention is a kind of method to measure the H2 storing material's PCT curved line. Especially it offers a kind of precise testing method which has wide use area to measure the H2 storing material's PCT curved line. This invention uses the volume method, that is to say, we will calculate the amount of H2 absorbed of the H2 storing material corresponding to different H2 pressure according to MBWR equation by continuously recording each part of pressure and temperature of H2 during the process of the H2 storing material absorbing or sending out H2, so as to get PCT curved line. After that we will realize the compression divisor's whole process of calculating and drawing picture by computer programming. As this invention has thought about the effect of the H2 storing room's temperature fluctuating, the PCT curved line will still be credible as though part of the room can not realize stable temperature. To sum up, this invention has good use value, making the instrument simple and easy to operate. At the same time we get higher degree of belief when we check the PCT curved line of carbon Nanometer pipe and V and so on which is the H2 storing material having high balance pressure.

The invention belongs to the technical field of gas production technologies in oil and gas fields, and particular relates to a method for measuring gas well critical liquid-carrying flow. The method includes the steps that gas well history data are searched for to obtain the oil pipe diameter D; gas well gas is sampled to measure gas components, and then the relative density gamma of the gas relative to air is calculated; bottom hole pressure Pm and temperature T are measured, and a corresponding compressibility factor is calculated through a iterative method according to the bottom hole pressure Pm and the temperature T; the critical liquid-carrying flow is calculated by using the oil pipe diameter D, the relative density gamma of the gas, the pressure Pm, the temperature T and the corresponding compressibility factor. According to the method for measuring the gas well critical liquid-carrying flow, a kinetic energy factor is cited and combined with practical production data of a Sulige gas field to determine a critical liquid-carrying flow formula, and a simpler and more reliable method is provided for determining the critical liquid-carrying flow of the Sulige gas field. The principle is reliable, and compared with an existing critical liquid-carrying flow model, the method fits the practical situation of the Sulige gas field better.

The invention provides a sending method, a receiving method, a sending system, a receiving system, a sending device and a receiving device for IQ (in-phase quadrature) data. The sending method for IQ data includes: IQ data to be sent are divided into a plurality of data blocks, each data block comprises a plurality of IQ data, continuous n effective bits are intercepted from the highest bit of each IQ data of each data block, compressibility factors are determined according to the intercepted effective bits, compressed IQ data formed by the compressibility factors, sign bits and the intercepted effective bits and are sent, and data size of the IQ data is reduced greatly since partial data of each IQ data are intercepted to be effective data and the compressed IQ data are formed. Therefore, hardware equipment need not be improved, the existing hardware equipment is directly used, and the transmission requirement for optical port rate can also be met.

The methods and apparatus for transporting compressed gas includes a gas storage system having a plurality of pipes connected by a manifold whereby the gas storage system is designed to operate in the range of the optimum compressibility factor for a given composition of gas. The pipe for the gas storage system is preferably large diameter pipe made of a high strength material whereby a low temperature is selected which can be withstood by the material of the pipe. Knowing the compressibility factor of the gas, the temperature, and the diameter of the pipe, the wall thickness of the pipe is calculated for the pressure range of the gas at the selected temperature. The gas storage system may either be modular or be part of the structure of a vehicle for transporting the gas. The gas storage system further includes enclosing the pipes in an enclosure having a nitrogen atmosphere. A displacement fluid may be used to offload the gas from the gas storage system. A vehicle with the gas storage system designed for a particular composition gas produced at a given location is used to transport gas from that producing location to a receiving station miles from the producing location.

The invention discloses a method for judging a tight sandstone gas reservoir based on the compressibility factor of the pore fluid. According to the technical scheme of the invention, the time difference of longitudinal waves and the time difference of transverse waves are provided based on the array sonic logging information. Meanwhile, the formation density of the density logging information is adopted as the input information to calculate a formation bulk modulus, so that the compressibility factor of reservoir rocks is derived. In combination with a formation bulk model, the compressibility factor of the pore fluid can be further derived. Finally, based on the compressibility factor of the pore fluid, whether the fluid is a tight sandstone gas reservoir or not can be judged. The acoustic information is deeply excavated in the method, and the difference between the compressibility factor of reservoir rocks and the compressibility factor of the pore fluid is utilized for the judgment of the fluid property. Therefore, the application range of the array sonic information for the judgment of the fluid property is broadened. Meanwhile, the judgment accuracy of the fluid property is improved.

The invention discloses an acquiring method and system for a compression factor. The method comprises the following steps: acquiring experimental compression factors Zi of a to-be-tested working medium with a preset fixed volume at (Ti, pi) state points when the to-be-tested working medium is of different preset fixed mass, i.e., acquiring discrete compression factors by using an experimental method; then constructing a training sample set according to the discrete compression factors; and constructing a compression factor prediction model by using an LS-SVM method according to the training sample set, wherein the compression factor prediction model is relational expression for a to-be-solved state point (T,p) and a compression factor Z corresponding to solving. According to the invention, the discrete compression factors are obtained by using an experiment method; then model prediction is carried out on the discrete compression factors so as to obtain the compression factor prediction model; and a continuous compression factor can be obtained by using the compression factor prediction model. Thus, the acquiring method and system can finish acquisition of the compression factor of any working medium at different temperature and different pressure.

The invention relates to a method for predicting gas well bottom flow pressure, which belongs to the fields of gas well dynamic analysis and working system optimization. Including (1) measuring or collecting the casing pressure, formation depth, relative density of natural gas, reservoir temperature, gas production, natural gas compression factor, and measured gas well bottomhole pressure parameters of a certain block; (2) making a gas drilling well Underflow pressure SVM predictor; (3) Input the measured or collected parameters into the SVM predictor for self-learning to determine the key parameters of the SVM predictor, namely the kernel function parameters , insensitivity coefficient and penalty factor (4) Input the casing pressure of the well to be predicted, the middle depth of the formation, the relative density of natural gas, the reservoir temperature, the gas production rate, and the compressibility factor of natural gas into the SVM predictor to obtain the prediction result of the bottomhole flowing pressure of the gas well to be predicted. The method is accurate and efficient, and it is a new practical method for predicting the bottom hole pressure of gas wells.

A light source optimization method of a photolithography machine. A pixelated light source is employed as particles. Quadratic sum of a difference between each point in an ideal shape and each point in a photoresist image, which is corresponding to a mask, under a present light source illumination mode is used as an objective function. By means of particle swarm optimization containing a linearly decreasing weight and a compressibility factor, light source shape is iteratively optimized by updating speed information and position information of the particles. The method can effectively improve a photolithographic imaging quality, is simple in principle, is easy to carry out and is high in convergence speed.

The cubic equations of state (CEOS) relate pressure, temperature and molar volume of a mixture. The deviation of the physical properties of a mixture from ideality is expressed by the compressibility factor. The compressibility factor is calculated from the CEOS. There is described a solution to the CEOS which provides a continuous solution for compressibility factors over the entire range of operating conditions. This solution avoids the non-unique roots, trivial roots and singularities that are present in the prior art solutions of the CEOS.

A method for delivering a fluid using a centrifugal pump (11). Machines (1, 6) and / or apparatus (3, 8), which influence the pressure and / or the temperature of the fluid, are disposed upstream of the centrifugal pump (11). At the inlet to the centrifugal pump (11), the fluid is regulated to achieve a specific entry state. According to the invention, the entry state of the fluid is regulated by using the machines (1, 6) or apparatus (3, 8) such that, in the centrifugal pump (11), the fluid only takes on states in which the compressibility factor of the fluid has already reached or exceeded the minimum thereof.

The invention provides a method for identifying a JPEG compressed digital picture, comprising the following steps: (1) diving the picture into blocks, and then processing and calculating a DCT coefficient of an unsaturated block in the picture; (2) keeping statistics of numbers of the AC coefficient in step (1) in a sector R1= (-1, +1) and a sector R2 = (-2, -1) U (+1, +2), recording as r1 and r2; (3) regarding s = r2 / r1as a feature of the picture and identifying the feature with a threshold T; if s is less than or equal to the threshold T, the picture is identified as being processed by JPEG compressing; otherwise, the picture is identified as not being processed by JPEG compressing. The invention can rapidly and effectively identify whether the picture is processed by the JPEG compressing; compared with the existing method, the identifying efficiency is greatly developed, thereby being capable of effectively identifying the picture having a size of 8 *8 and a JPEG picture having a compressibility factor greater than 95.

The invention provides an ultra-low permeability oil and gas reservoir micro-nano pore bubble point pressure numerical simulation method and device. The method comprises the steps: determining a balance coefficient; Determining a liquid phase compression factor, an escape coefficient and an escape degree according to the balance coefficient, the capillary pressure and the surface tension; According to the balance coefficient, determining and normalizing the gas phase molar fraction; Determining a gas phase compression factor, an escape degree coefficient and an escape degree according to the gas phase mole fraction, capillary pressure and surface tension; Determining a ratio of the liquid phase to the gas phase escape degree according to the liquid phase compression factor, the escape degree coefficient and the escape degree as well as the gas phase compression factor, the escape degree coefficient and the escape degree; And judging the balance condition of the gas phase and liquid phase escape degree according to the ratio, and if the gas phase and liquid phase escape degree are unbalanced, correcting the balance coefficient and the corresponding bubble point pressure until the gas phase and liquid phase escape degree are balanced. According to the technical scheme, the numerical simulation precision of the nano-pore multi-component fluid bubble point pressure of the ultra-lowpermeability oil and gas reservoir is improved, so that the yield prediction precision of the ultra-low permeability oil and gas reservoir is improved.

The invention discloses a decoupling algorithm suitable for real-time computing of aerodynamic parameter distribution on wings. According to the algorithm, a new decoupling parameter sigma is introduced on the basis of a wing lifting line model computing result, and the decoupling parameter sigma is defined as sigma=alpha<induced> / lambda, wherein alpha<induced> is an induced attack angle, lambda is a compressibility factor, and Ma is a Mach number. Therefore, an empirical formula is obtained, and the decoupling algorithm is designed based on the empirical formula. Through the decoupling algorithm, real-time computing of aerodynamic parameter distribution on the wings can be realized, and the decoupling algorithm is suitable for establishment of a propeller-engine-aircraft integrated real-time model.

A method and a gas flow meter for measuring gas flow, having a cylinder, and a piston disposed movably within the cylinder, forming a clearance seal between the piston and the cylinder. A gas flow to be measured is directed to the cylinder so as to move the piston within the cylinder. From the detected movement of the piston, electrical signals representative of the gas flow are generated. Gas temperature and pressure data are also measured. A controller calculates a standardized flow rate of gas based on gas species information, and determines a compressibility factor based on the gas species information and the temperature and pressure data, and calculates a corrected flow rate. The compressibility factor is determined from a table pre-stored in a memory.

Blowout preventers, fluid pressure systems and portions thereof may be tested for leaks by calculating an Apparent Compressibility Factor which is determined during initial pressurization of the system to the test pressure. The equivalent decay rate is calculated by measuring the amount of intensifying fluid required to be added to maintain the system at the test pressure level. The equivalent decay rate in psi per minute is then compared to the acceptable decay rate for the pressure level of the test to determine if the system passed the test.

The invention provides a liquid rocket engine thermal test parameter setting method considering a real gas effect, and aims to avoid deviation of turbine power calculation. According to the method, onthe basis of turbine power of ideal gas, the influence of a real gas effect on turbine adiabatic work is considered, and the turbine power of the ideal gas is corrected through linear weighting of agas compression factor, wherein the gas compression factor is solved based on an RKS state equation; and based on the turbine power obtained through calculation, other thermal test parameters are calculated according to flow, pressure and power balance. According to the invention, the influence of the real gas effect on the turbine power is fully considered, and the set engine joint test and hot test working condition parameters are more accurate, so that the test risk can be reduced.

The invention discloses a self-adaptive gray-scale image enhancement system. The system comprises an image reading module, an image pre-processing module, a parameter optimization module and an image enhancement and output module. In the system, an input gray-scale image is firstly normalized; then the gray-scale image is enhanced by use of a transformation formula, and parameters in the transformation formula are determined through an improved intelligent optimization method. A grouping operation is added in the improved optimization method and the local optimum can be prevented in the optimization process; meanwhile, in the improved optimization method, a compressibility factor in the formula is updated and changes adaptively according to iteration count, and the convergence performance of the algorithm is improved. By use of the improved intelligent optimization method, the system can rapidly and accurately determine the optimal parameter, then carries out the enhancement operation on the gray-scale image and finally outputs the gray-scale image. The system has the characteristics of good enhancement effect and high running efficiency.