33 results about "Pressure propagation" patented technology

A method and apparatus for determining a cardiovascular parameter including receiving an input signal corresponding to an arterial blood pressure measurement over an interval that covers at least one cardiac cycle, determining a propagation time of the input signal, determining at least one statistical moment of the input signal, and determining an estimate of the cardiovascular parameter using the propagation time and the at least one statistical moment.

A water leakage monitoring system including a water leakage position estimator which includes a periodic data acquiring unit for fetching predetermined-period flow rate pressure data stored in a monitoring device, and for fetching a signal related to a flow rate change and pressure changes expecting a water leakage reaction time calculating unit for calculating a pressure reaction time lag between two pressure changes, a pressure propagation velocity estimating unit for estimating a pressure propagation velocity using the pressure reaction time lag and a distance between two pressure gauges located in a water distribution block stored in a pipeline network map data, and a flow rate change position estimating unit for receiving a signal related to the flow rate change, and estimating a flow rate change position using pressure propagation velocity and a flow meter and pressure gauge locating positions of the pipeline network map data.

The invention belongs to the technical field of mineral resources, and particularly relates to a method for computing unsteady state output of a shale gas reservoir complex fracture network. The method comprises the following steps that S1, basic parameters of shale gas reservoir strata and shale gas are collected, and a shale substrate porous media capillary tube permeability model is established; S2, shale gas reservoir microseism fracture imaging data is collected, a box method is applied to acquire fractal dimensions, a two-dimensional discrete fracture network model is established, and animproved cubic law is adopted to calculate the complex fracture network permeability; S3, it is considered that a shale gas reservoir fracturing horizontal well outer region is a substrate area infiltration area and a shale gas reservoir fracturing horizontal well inner region is a complex fracture network area flow area, and a shale gas reservoir fracturing horizontal well steady-state productivity model is established; according to a shale gas pressure propagation radius equation and a shale gas reservoir material balance equation, a continuous quasi-steady method is applied to establish ashale gas reservoir fracturing horizontal well unsteady state model. The method for the computing unsteady state output of the shale gas reservoir complex fracture network has the advantages that theconsideration factors are close to the actual conditions of strata, and computed results are more accurate.

Unless an abnormality exists in piping introducing a pressure from front and rear of DPF 22 into a differential pressure sensor 45, pulsations of pressure propagation through an exhaust passage 21 is offset in a detection value of a pressure difference of the differential pressure sensor 45, and an amplitude of the detection value of the DPF pressure difference resulting from pulsation of the pressure becomes small. If a crack exists in one of the piping 3a and 3b, the influence of a pulsation of the pressure appears in the DPF pressure difference and the amplitude of the detection value of the DPF pressure difference becomes large. The amplitude of the detection value of the DPF pressure difference is compared with the reference value and is detected as being abnormal when it is large, utilizing the phenomenon described above.

The invention discloses a method for calculating a non-steady state yield of a volume fractured horizontal well of a shale gas reservoir. The method comprises the following steps of dividing the reservoir into a volume fractured region and a non-transformed matrix region, and collecting basic parameters of the volume fractured region, the non-transformed matrix region and the horizontal well, wherein the volume fractured region is Darcy flow, and the non-transformed matrix region is Knudson flow; according to a mass conservation law, establishing a steady-state yield formula of the volume fractured horizontal well of the shale gas reservoir; based on a pressure propagation formula, the steady-state yield formula and a matter balance equation, calculating the non-steady state yield of the volume fractured horizontal well of the shale gas reservoir by applying a continuous quasi-steady method; and repeating the previous step, and performing calculation to obtain the non-steady state yield of the volume fractured horizontal well of the shale gas reservoir. The method fully considers a process that a pressure is propagated to a boundary gradually in a production process of the volume fractured horizontal well of the shale gas reservoir, different seepage laws of shale gas in a volume transformation region and the non-transformed matrix region, and adsorption and desorption effects of the shale gas, so that actual conditions are better met.

The invention provides a draw-down test analysis method for an underground shut-in water well with a low-permeability storage layer, and the method is applied to the technical field of oil well tests in oil fields. In the method, a base data analysis unit, a primary base feature analysis unit, a secondary main control factor analysis unit and a tertiary data analysis model unit are utilized, wherein the primary base feature analysis unit is used for utilizing the base data of the base data analysis unit to determine a geologic model for detection and analysis, judging the pressure propagation characteristic of the low-permeability storage layer and forming the superposition mode of bottomhole pressure drawdown in a drawn-down test; the secondary main control factor analysis unit is used for carrying out diagnostic analysis on the control degree of a geologic factor, a process factor and a dynamic factor on the pressure drawdown mode of the drawn-down test and determining main control factors according to the conclusion of the primary base feature analysis unit; and the tertiary data analysis model unit is used for selecting the draw-down test analysis method according to the conclusions of the primary base feature analysis unit and the secondary main control factor analysis unit and adopting different well test interpretation models according to the main control factors.

A sleeve valve for fluid flow between a hydrocarbon reservoir and a well including a fixed outer sleeve with openings and a movable inner sleeve with openings which can be aligned and misaligned with the outer sleeve openings in order to admit or shut off the fluid flow. The outer sleeve opening is provided with a movable sealing element that has a through-going radial opening adapted to rest around the opening in the inner sleeve, and a tension element presses the sealing element against the inner sleeve. A portion of the side face of the sealing element forms a pressure face which under the effect of pressure in a pressure chamber presses the sealing element against the inner sleeve. The pressure chamber is via at least one connection connected to at least one pressure source whereby pressure propagation from the pressure source to the pressure chamber causes the sealing element to be pressed even more against the inner sleeve.

The invention discloses a simulating device and method for a water producing source and a pressure-dropping path during coal-rock reservoir discharge and recovery. The simulating device comprises a sample clamping assembly, a stratum pressure simulating assembly, a fluid supplying/discharging assembly and an information acquisition and control assembly. The sample clamping assembly comprises at least one clamping device, and each clamping device comprises a coal sample clamping device body and a rock sample clamping device body arranged above the coal sample clamping device body. The stratum pressure simulating assembly comprises an oil tank, an oil pressure pump, a flow divider, an axial pressure loading cylinder and a confining pressure loading cylinder. The fluid supplying/discharging assembly comprises a fluid storage tank, a booster pump, a quantitative fluid storage tank and a simulating shaft. Through the simulating device and method, the developing characteristic, the permeability and the water-bearing property of different fractures and flowing of fluids in and between rock stratums in the coal-rock reservoir discharge and recovery process in a combination mode can be simulated, and scientific bases are provided for judgment of the water producing source and the pressure transmission path under the corresponding geological condition.

The invention relates to a manufacturing method of a septum device, belonging to the technical field of pressure measuring. The method comprises the following steps: a processed round metal plain film is fixedly connected with a processed septum junctor, an upper septum junctor and a lower septum junctor are connected in a sealing way, the round metal plain film is punched by pressure medium and is jointed with a function surface on the septum junctor under the pressure action of the pressure medium to generate tension set; a function surface completely coinciding with the function surface on the septum junctor is formed on the round metal plain film which is shaped as a metal film with waviness; the metal film is provided with a function surface completely coinciding with the function surface on the septum junctor, the junctor has accurate positioning and accordant die space and especially plays the role of overvoltage protection, so the metal film cannot be damaged in overvoltage, thereby the pressure propagation precision of the septum device is enhanced. The invention also provides a septum device and a septum pressure gauge.

A canister is furnished to store evaporative fuel. A purge line is furnished to ensure that the canister communicates with an internal combustion engine intake path. The purge line is provided with a D-VSV (purge control valve) that controls the continuity of the purge line. Further, a check valve is furnished to control the pressure propagation from the intake path to the canister at the time of backfiring.

The invention provides an air tightness detecting device and detecting method for a movement process of a high speed train. The device includes two air pressure transmitters and one single chip microprocessor disposed on a head locomotive of the high speed train and two air pressure transmitters and one single chip microprocessor disposed on a tail locomotive of the high speed train. The device isadvantaged in that the structure is simple and air pressure leakage information can be displayed in real time. When air pressure leakage occurs, the position of an air pressure leakage point can be calculated; data can be stored in a CCU(Central Control Unit) and can be transmitted to a DMI (Driver-Machine Interface) through an MVB (Multifunction Vehicle Bus) connected with the CCU. The detectionmethod is that when air pressure leakage occurs, the single chip microprocessors on the head locomotive and the tail locomotive send air pressure abnormal values and abnormal moments measured by theair pressure transmitters to the CCU, calculate the air pressure leakage position according to time difference in combination with vehicle speed, vehicle length and air pressure propagation rate and gives real time alarm and display in the DMI. At the same time, the CCU can be started during in-factory maintenance of the high speed train and information of the air pressure leakage position can becalled, so that a large amount of time and labor can be saved in air tightness check.

The invention relates to controlling a vacuum system comprising a vacuum generator. A method for controlling a vacuum generator in a vacuum system for transportation of objects, the vacuum system comprises a vacuum generator driven by a compressed air flow via a first on/off valve, a second valve, which is arranged to supply compressed air into the vacuum system, one centralized pressure sensor used for monitoring a system pressure inside the vacuum system and for adaptive blow-off; and a vacuum system controller, wherein if the on/off valve is not flowing air to the vacuum generator, the vacuum system controller indicates a state of no vacuum generation, and the second valve is activated, allowing an amount of compressed air to flow into the vacuum-system for blow-off, blow-off is terminated and excessive air injected into the system is released through the vacuum gripper means, analyzing pressure propagation following blow-off for calculating a duration of when the vacuum system is being fully pressure-equalized in parts of the vacuum gripper means by using a compensation factor.

An inkjet recording apparatus includes actuators provided in an inkjet head, and a drive voltage generator that drives each actuator. The drive voltage generator is configured to set the cycle time Tc, the drop cycle Td, the number of ink droplets N for a maximum tone, and the inactive period Te in a relationship of Tc=Td×N+Te, set the drop cycle Td and the inactive period Te, by referencing pressure propagation time Ta in relationships of Td=n×Ta (where n=1, 2, 3, . . . ) and Te=(0.5+m)×Ta (where m=1, 2, 3, . . . ), and make an output timing of the final drive pulse signal for a dot of a tone other than the maximum tone coincide with an output timing of the final drive pulse signal for the maximum tone.

An ink-jet recording apparatus includes a pressure chamber that contains ink, a nozzle communicating with the pressure chamber, which ejects the ink from the pressure chamber, an ink-jet head having an actuator that increases and decreases the capacity of the pressure chamber, and a driving signal generation unit that supplies the actuator with a driving signal to eject an ink drop from the nozzle. When no ink is ejected from the nozzle, the actuator is supplied with a very low pressure driving signal to increase the capacity of the pressure chamber and then return the increased capacity to an original size. The pulse width of the very low pressure driving signal is about twice as long as a pressure propagation time period during which a pressure wave in the ink propagates through the pressure chamber.

The invention discloses a heterogeneous buried hill gas reservoir well control reserve prediction method and device.The method comprises the steps that a gas reservoir is divided into N seepage areas in the radial direction of a borehole according to the heterogeneous condition, the N seepage areas are distributed in a concentric annulus mode, and basic parameters of the N seepage areas are obtained; a pressure propagation equation of the gas reservoir from the concentric circle center in the radial direction is established, and the gas reservoir well control radius is obtained through the pressure propagation equation; and well control reserves are predicted by using the gas reservoir well control radius. The method can consider the characteristics of heterogeneous distribution of buried hill gas reservoirs, is more consistent with the actual situation, and achieves the accurate prediction of well control reserves.