748 results about "Pressure curve" patented technology

The present invention relates to a solution for controlling the pressure/flow of breathing gas to a mechanical ventilator (4) by using an energy of breathing analysis and further to provide a pressure relief during exhalation and a trigger determination when to start the pressure relief using energy content of breathing in analysis for determining a pressure curve form during at least a portion of the expiration phase.

The application discloses a pressure calibration and detection method for an electronic pressure cooker. A pressure cooker enters a pressure point recording mode; when the pressure inside the pressurecooker rises, a heating plate acting film deforms to adjust an iron core position of a pressure sensor, so that the iron core and a coil of the pressure sensor make displacement to change the inductance value; the variable of the inductance value is transformed into a corresponding frequency value by a conversion circuit; a processing chip records and stores information; when the pressure insidethe pressure cooker is being a pressure P1 and a pressure P2 respectively, the processing chip records corresponding frequency values H1 and H2 respectively; on the basis of the P1, P2, H1, and H2, apressure curve slope C is calculated, wherein the C meets a formula: C=|H2-H1|/(P2-P1); a frequency value X is collected in real time; when the X is larger than or equal to H1, the current pressure PXin the pressure cooker meets a formula: PX=[P1-(X-H1)/C]; and when the X is less than the H1, the current pressure PX in the pressure cooker meets a formula: PX=[P1+(H1-X)/C]. Therefore, the detection efficiency, detection accuracy and pressure cooker quality are improved.

An apparatus and method are provided for treating wound with negative pressure. The apparatus includes a wound cover, a first pump for providing said negative pressure at a chosen pressure level to the wound, a canister, a first conduit between the wound cover and the canister, first means for measuring the pressure within the canister, and a second conduit which connects the canister with the first pump. A circulating pump is arranged to intermittently transport a gas volume from the canister to the wound region via a third conduit and back to the canister via the first conduit in order to press out possible exudates from the first conduit to the canister. A second means analyzes the pressure curve over time of said pressure in the canister and a third means indicates by alarm when said pressure curve differs from a normal cyclical form.

The invention discloses a method for calculating tight sandstone reservoir permeability based on hole feature parameters. The method includes the steps of calculating hole structural parameters through a rock core mercury penetration experiment, establishing a permeability well logging interpretation model through a first characteristic function which is established through the hole structural parameters, converting nuclear magnetism T2 spectrum into a pseudo capillary pressure curve through correlations existing between nuclear magnetism T2 spectrum distribution and mercury penetration hole diameter distribution, and calculating the reservoir permeability according to a second characteristic function which is established through the pseudo capillary pressure curve. In practical application, the quantitative, continuous and high-precision pseudo capillary pressure curve is obtained through nuclear magnetic resonance well logging information under the condition that laboratory mercury penetration information does not exist, and finally, calculation of the reservoir permeability is conducted according to the second characteristic function which is established through the pseudo capillary pressure curve.

The invention discloses a sliding pressure curve correcting method, which comprises the following steps that: the power values at a plurality of load points are obtained, in addition, a first main steam pressure value and a second main steam pressure value corresponding to the power values at each load point are obtained, the difference value of the first main steam pressure value and the second main steam pressure value at each load point is introduced into the function relation of the power value and the first main steam pressure value at the load point, the variable quantity delta PW of the power value at each load point is obtained through calculation, the back pressure item correcting factor K is obtained through calculation according to the delta PW and the back pressure change quantity delta PB, and the power value after the correction is obtained according to a formula of PW=PT+(PB-6.2)*K, so the sliding pressure operation mode of a machine unit at each load point is carried out according to the function relationship of the power value and the first main steam pressure value at the load point. The method has the advantages that the sliding pressure optimization curve is obtained through the practical operation of the machine unit, the back pressure item correction on the load in the sliding pressure curve is carried out in the practical operation, and the precision of the sliding pressure curve is improved. The invention also provides a sliding pressure curve correcting device.

The present invention relates to a method for monitoring a fluid transfer process, including the steps: providing an allowable pressure profile; detecting a pressure occurring in the course of the fluid transfer process; comparing detected pressure with the allowable pressure profile and signaling an error, if the detected pressure is not within the allowable pressure profile. The allowable pressure profile is defined by interpolation points, the interpolation points being based on a probability function representing a family of pressure courses of a plurality of fluid transfer processes. The allowable pressure profile can be divided into at least two distinct process sections, each section corresponding to a distinct process phase of the fluid transfer process. The probability function is calculated from a family of test pressure curves and reflects the statistical behavior of the pipette system. The present invention further relates to a computer readable medium for storing interpolation point information as well as to a kit-of-parts comprising a device implementing the inventive method, together with a computer readable medium for storing interpolation point information.

The present invention is a method and system for controlling a motor attached to a variable displacement pump for providing a supercritical fuel and fuel pressure to a plurality of fuel injectors of a vehicle engine. The system includes: a pump having a motor; a tachometer sensor for measuring a rotational displacement of a motor shaft and for sending a tachometer count value to a memory device; an engine control unit configured to generate a rotational displacement vs. pressure profile of the pump based on the displacement value and pressure value; an accumulator attached to the output of the pump; and a control method that allows for a look ahead and prediction of the pump requirements needed in a future cycle based on current demand to allow for an efficient fuel injection pump.

During a method of evaluating a dosing operation, carried out by means of a dosing pump, for dosing a liquid medium in a vessel, filled at least partially with a gas, a pressure profile of the gas, present in the vessel, is detected at least periodically during the dosing operation. This pressure profile is compared with a desired value profile, prescribed for a control unit of the dosing pump, of the pump rate or pump output defining the dosing operation, and an evaluation result is issued in dependence on the comparison. In such case, the dosing operation is evaluated to be faulty or in need of correction when it is determined that the detected pressure profile over time with the prescribed pump rate or prescribed pump output lies outside a desired value range. A plurality of error conditions for the evaluation of the dosing operation are used, which consider the pressure development in a time window after a prescribed change in the defining pump rate or pump output.

The invention discloses a reservoir classification method based on rock electricity parameters, and belongs to the field of hydrocarbon reservoir evaluation. The method is based on rock electricity experiment theoretical model deduction, a theoretical value range and a value trend of rock electricity experiment data of reservoirs under different pore structures are formed, and reservoir pore structure subareas on a rock electricity data F-phi plate are formed; and corresponding electrical logging data are utilized in combination with rock electricity experiment data and mercury injection capillary pressure curve data to determine rock electricity method quantitative classifications, and the method at least includes: Step 1) establishing a rock electricity method classification bases; Step 2) forming a classification plate; Step 3) establishing a quantitative classification evaluation basis; and Step 4) determining classification grades of the reservoirs. According to the reservoir classification method based on rock electricity parameters in the invention, by checking distribution of the rock electricity data on the F-phi plate and discovering that rock samples of reservoirs of different classes fall on distinguishable different subareas on the F-phi plate, continuous evaluation knowledge can be provided, and a verification effect is good.

The invention provides an acquisition method of a sliding pressure curve of a steam turbine by using a main steam flow as a scheduling variable, relates to a determining method of a sliding pressure curve, and aims at solving the problem that the heat supply steam extraction capacity variation and back pressure variation operation status cannot be fulfilled by one sliding pressure curve. The method comprises the following steps: selecting M main steam flows according to the type of a heat supply steam extraction unit, wherein M is an integer of greater than 2, and each main steam flow is respectively subjected to the following steps: N different main steam pressure values of the heat supply steam extraction machine are selected with the main steam flow being the selected main steam flow, and N is an integer of greater than 4; calculating heat consumption values of the heat supply steam extraction unit; performing curve fitting on the N main steam pressure values and corresponding heat consumption values thereof according to a least square method to determine an optimal main steam pressure value; and performing linear fitting on the acquired M main steam flows and the corresponding optimal main steam pressure data thereof to acquire a final sliding pressure operation curve. The acquisition method is used for determining the sliding pressure curve of the steam turbine.

A method for monitoring the exhaust gas recirculation of an internal combustion engine by pressure sensing, in which exhaust gas is recirculated from an outlet side of a combustion chamber assemblage via an exhaust gas recirculation conduit to an inlet side of the combustion chamber assemblage. Reliable monitoring of the exhaust gas recirculation with relatively little complexity is achieved by the fact that a pressure curve is sensed in at least one combustion chamber and a thermodynamic parameter is ascertained therefrom as an actual value; that a setpoint value of the parameter, which setpoint value takes into account the current operating point of the internal combustion engine, is made available, and a deviation between setpoint value and actual value is determined; and that a datum regarding the current exhaust gas recirculation state, as compared with its normal state, is obtained from the deviation.

The invention discloses a propellant powder variable capacity burning rate testing device, belonging to the explosive property test field. The technical characteristics include that a pressure sensor is respectively arranged on the wall of a combustion chamber and a piston, the piston and a piston cavity are in slide fit, a piston rod fixedly connected with the piston is used for leading the connecting wire of the sensor in the piston to the outside of the piston cavity, and ignition cartridge bag and propellant powder to be tested are placed in the combustion chamber; when in test, the propellant powder to be tested is burned in the combustion chamber and the piston is pushed to move, the two pressure sensors respectively record pressure curves of combustion chamber fixed position and piston bottom, namely curve p1-t and curve p2-t, and a high speed camera record piston rod moving stroke-time curve, namely L-t curve; and computing and processing are carried out by virtue of a data acquisition and processing system, thus finally obtaining the burning rate pressure coefficient and burning rate pressure index of propellant powder to be tested. The invention not only solves the problem of measuring propellant powder variable capacity burning rate but also solves the technical problem that cartridge bottom pressure measurement is simulated.

The invention discloses a gas water heater, and a safety control system and a method thereof. The system comprises an exhaust fan, a rotary speed detection unit, a power acquisition unit, a rotary speed difference value acquisition unit and an exhaust control unit. The rotary speed detection unit is used for detecting the rotary speed of the exhaust fan; the power acquisition unit is used for acquiring an output power set value of the exhaust fan; the rotary speed difference value acquisition unit is used for acquiring a rotary speed actual value and a rotary speed reference value of the exhaust fan according to the output power set value, and calculating a difference value between the rotary speed actual value and the rotary speed reference value of the exhaust fan; and the exhaust control unit is connected with the exhaust fan, the rotary speed detection unit, the rotary speed difference value acquisition unit and the power acquisition unit, and is used for correcting a preset outlet air pressure curve of the exhaust fan according to the difference value, judging the air pressure situation of an air outlet of the exhaust fan according to the rotary speed, the corrected outlet air pressure curve and the output power set value of the exhaust fan, and adjusting the output power set value of the exhaust fan according to the air pressure situation of the air outlet of the exhaust fan. The system can ensure the gas water heater to have a favorable combustion condition and operate safely and reliably, and is high in control accuracy.

An arterially measured pressure signal is continuously read in and temporarily stored in the working memory (RAM). The function p(t) is processed by the central processing unit (CPU), to calculate the heart/time volume PCCO and other hemodynamic parameters. The calculation comprises the following steps: The systemic vascular resistance SVR_k is calculated for the current pulse period. The stroke volume SV_k is numerically determined from the pressure values of a pulse period, according to the following equation: ${\mathrm{SV}}_k\propto \sum \left(\frac{p_i\left(t\right)}{{\mathrm{SVR}}_k}+C_k\left(p_i\right)\frac{d{p}_i}{dt}\right)$

with the compliance C(p)=(MAP−CVP)_k/[SVR·<dp/dt>_k]·f(p). The difference between the mean arterial pressure MAP and the central venous pressure CVP, and the mean incline of the pressure curve in the diastole <dp/dt>, are re-determined for the current pulse period. The heart/time volume calculated in the current pulse period results from PCCO_k=SV_k·HR. Therefore, continuous recalibration of the systemic vascular resistance and of the compliance takes place, from the continuously determined pressure measurement data.

The invention relates to a molten drop furnace for measuring a molten drop point of iron ore. The furnace comprises a furnace body and a control device, wherein a sealed hearth is formed in the middle of the furnace body; and a heating device is arranged outside the hearth. The furnace is characterized in that: a graphite crucible is arranged inside the hearth; the heating device is controlled toheat the hearth, the graphite crucible and an ore sample in the graphite crucible; a hollow graphite pressing rod is arranged above the furnace body; a thermocouple is arranged inside the hollow graphite pressing rod; the lower end of the thermocouple passes through a graphite plate inside the graphite crucible and is contacted with the ore sample; a sealed sampling box is arranged below the furnace body; and a receiving crucible for accommodating molten metal liquid is arranged under the graphite crucible inside the sampling box. The molten drop furnace can accurately measure temperature of a material, the temperature of the material serves as softening temperature and dropping temperature of the iron ore, the accuracy of the dropping temperature is greatly improved, the measuring accuracy at the molten drop time point is improved, and a temperature and pressure curve at a molten drop moment is accurately captured.

The invention discloses a fracturing method for deep shale gas through a V-shaped pressure curve. The fracturing method comprises the steps of (1) key reservoir parameter evaluation, (2) optimizationof fracture parameters and fracturing construction parameters, (3) perforation position determination and perforation operation, (4) acid pretreatment, (5) variable-displacement and low-viscosity slick water joint forming construction, (6) powder pottery construction for adding different sand liquid ratios into low-viscosity slick water, (7) medium-particle-size proppant construction for adding different sand liquid ratios into medium-viscosity slick water, (8) high-viscosity gel and large-particle-size carrying proppant construction, and (9) displacing operation. According to the fracturing method, complexity of fracturing fractures of the deep shale gas is improved, the filling ratios of systems with different scales of fractures such as near wells, far wells, main fractures and micro-fractures are increased, the effective stimulation volume of the deep shale gas is increased, and the yield increasing and stabilizing effects after pressure are improved.

The invention provides a pipeline leakage monitoring method and device. The pipeline leakage monitoring method provided by the present invention includes: collecting the flow and pressure at the head end and the end of the pipeline; when an inflection point appears on the flow curve at the head end or the end of the pipeline, judging whether the pressure curve at the head end or the end of the pipeline is There is an inflection point, if the pressure curves at the head end and the end of the pipeline have inflection points, record the time between the first time when the inflection point appears in the pressure curve at the head end of the pipeline and the second time when the inflection point occurs in the pressure curve at the end of the pipeline and determine the distance between the leak point and the beginning of the pipeline or the distance between the leak point and the end of the pipeline according to the time difference and the propagation velocity of the liquid pressure wave in the pipeline. The invention can realize the accurate positioning of the leakage point on the pipeline by using the change of the flow at both ends of the pipeline and the time difference of the inflection point of the pressure curve.

The invention discloses a method for constructing pseudo capillary pressure curves by using NMR (nuclear magnetic resonance) logging. The method comprises the steps as follows: according to NMR logging data measured actually and limited capillary pressure data, seven different relaxation time is set; NMR T2 spectra are divided into eight parts; the percentage content of porosity components of the eight parts is calculated; a transformation model between the mercury-injection saturability and the percentage content of the NMR porosity components under different mercury-injection pressures is built; according to the transformation model, the mercury-injection saturability under different mercury-injection pressures is calculated; according to the calculated mercury-injection saturability and the mercury-injection pressure corresponding to the mercury-injection saturability, the pseudo capillary pressure curves are constructed; and according to the pseudo capillary pressure curves, pore throat radius distribution is obtained, evaluation parameters of a pore structure of a reservoir stratum are calculated, and the purpose of constructing the pseudo capillary pressure curves by using NMR logging data accurately and carrying out continuous quantitative evaluation on the pore structure of the reservoir stratum is achieved.

The invention relates to a porous medium water saturation calculation method based on network simulation, and the method sequentially comprises the following steps that: (1) a selected rock sample is cut into three sections, wherein an A section is used for a rock electrical experiment, a B section is used for wettability measurement, and a C section is used for cast body sheet analysis; (2) a formation factor F is calculated; (3) the normalized standard deviation Sigma r of the pock pore radius is calculated; (4) an average coordination number z is calculated; (5) a porous medium percolation network model is built and a parameter a' is calculated; (6) the number of a' is determined; and (7) water saturation Sw is calculated. According to the porous medium water saturation calculation method based on network simulation, apart from that the rock electrical experiment is carried out, the average coordination number z of the porous medium and the normalized standard deviation Sigma r of the pock pore radius need to be analyzed and calculated through capillary pressure curves and cast body sheets, and a network simulation technology is applied; and consequently, results by adopting the calculation method are more true and reliable, and bases and means are provided for the accurate and quantitative calculation of the water saturation of a reservoir stratum.

Foldable boom inner wings are attached to a boom center frame through a rocker attached to a breakaway hydraulic cylinder pressurized to full stroke and connected to an accumulator. When a wing impacts an object, the impact load is transmitted through the fold cylinder and rocker into the breakaway cylinder. As the breakaway cylinder retracts to allow the wing to pivot, pressure builds in the system in three stages. First pressure builds along an accumulator pressure curve until a relief valve in the hydraulic system actives to initiate the second stage wherein oil is dumped through the relief valve. Thereafter, pressure is again allowed to build along the same accumulator curve to absorb impact hydraulically before the cylinder reaches full stroke. The staged pressure buildup prevents boom momentum from gaining and loads from increasing above the strength of the overall structure.

An apparatus for measuring the parameters associated with underwater laser impact shaping is composed of laser generator and its control system, water film thickness regulating system, pressure detecting system, restricting layer and absorptive-layer material. Its method includes such steps as generating laser pulses, emitting them via restrictive layer onto the absorptive layer coated on the protecting film of sensor, evaporating and ionizing the absorptive layer to generate impact waves, transferring them via protecting film to sensor for generate electric signal, detecting and amplifying, converting, displaying the pressure curve of impact waves on oscilloscope, analyzing the influence of water film to the parameters of impact waves, and determining optimal thickness of water film.