High-pressure fluid expansion ejection performance prediction method, device, storage medium and equipment

Abstract

A method, device, storage medium, and equipment for predicting the performance of high-pressure fluid expansion ejection. The method obtains the structural parameters of the ejection device and the initial thermophysical parameters of the working fluid by setting a measuring tool; sets the fluid working fluid state equation, equation parameters, and coefficients in the calculation process; calculates and obtains the working fluid density and specific internal energy of the fluid working fluid in the high- and low-pressure chambers, and the displacement and velocity of the target load; calculates and obtains the saturation point specific internal energy of the fluid working fluid, and judges the phase state of the fluid working fluid through the saturation point specific internal energy; calculates and obtains the thermophysical parameters of the fluid working fluid in a preset phase state; selects a set time step and a set numerical solution strategy, performs iterative calculations, and obtains the thermophysical parameters of the fluid working fluid in the high- and low-pressure chambers and the real-time motion state of the target load during the ejection process. The present invention takes into account the phase transformation of the working fluid and is applicable to various real fluid state equations, and obtains the thermodynamic parameters of the high- and low-pressure chambers and the motion state parameters of the target load in real time during the ejection process.

Description

Technical Field

[0001] The present invention relates to the field of energy and power technology, and in particular to a method and device for predicting high-pressure fluid expansion ejection performance. Background Art

[0002] High-pressure fluid expansion ejection technology uses the high-pressure fluid pre-filled in the pressure vessel to expand and perform work, pushing the target payload to move and thus enabling it to obtain the required kinetic energy. It is widely used in the fields of aircraft ejection, weapon launch, obstacle removal, firefighting and rescue. Depending on the specific application scenario and target payload characteristics, commonly used high-pressure fluids include but are not limited to: air, nitrogen, helium, hydrogen, water vapor and gunpowder gas. In order to fully utilize the internal energy of the high-pressure fluid and improve the energy conversion efficiency of the ejection device, the high-pressure fluid generally takes on a single phase form such as gaseous or supercritical during the ejection process. The existing performance prediction method of the high-pressure fluid expansion ejection process is also mainly constructed based on the assumption of a single phase of the fluid.

[0003] In recent years, new fluids have been used in expansion ejection devices. These fluids can exhibit phase transitions from supercritical to gas-liquid equilibrium and then to gas during the ejection process. When considering off-design ejection conditions, conventional fluids will also experience phase changes. Existing research indicates that the ideal gas equation of state (EoS) often predicts a significant deviation from actual performance. Furthermore, a wide variety of real fluid equations of state are available, and the complexity of their mathematical expressions varies significantly.

[0004] Therefore, it is necessary to develop a universal performance prediction method for the expansion and ejection process of high-pressure fluid working fluids that can take into account the transformation between different phases of various working fluids and is applicable to various real fluid state equations, and to develop related computer programs and products. Summary of the Invention

[0005] To this end, the present invention provides a method and device for predicting the ejection performance of a high-pressure fluid expansion projectile. This method considers the phase transitions of the working fluid and is applicable to various real-world fluid equations of state. It provides real-time thermodynamic parameters of the high- and low-pressure chambers, as well as the kinematic parameters of the target payload, during the ejection process. This method concisely and intuitively characterizes the high-pressure fluid expansion ejection process, predicting its ejection performance and providing a reference for the engineering design of ejection devices.

[0006] In order to achieve the above objectives, the present invention provides the following technical solutions: In a first aspect, a method for predicting the ejection performance of a high-pressure fluid expansion ejection is provided, comprising:

[0007] The structural parameters of the ejection device and the initial thermophysical parameters of the fluid working medium filled in the high-pressure and low-pressure chambers are obtained by setting measurement tools and setting sensors; the state equation of the fluid working medium, the equation parameters and the coefficients in the calculation process are set;

[0008] The working medium density and specific internal energy of the working medium in the high-pressure and low-pressure chambers are calculated by using the set fluid working medium state equation; the displacement and velocity of the target load are calculated by using the target load motion state calculation equation;

[0009] Calculate and obtain the saturation point specific internal energy of the fluid working medium, and determine the phase state of the fluid working medium based on the saturation point specific internal energy; calculate and obtain the thermophysical property parameters of the fluid working medium in a preset phase state;

[0010] A set time step and a set numerical solution strategy are selected, and iterative calculations are performed using the fluid working medium state equation and the target load motion state calculation equation to obtain the thermophysical parameters of the fluid working medium in the high- and low-pressure chambers and the real-time motion state of the target load during the ejection process; the iterative calculation process ends when the target load displacement reaches the maximum motion stroke in the launch tube or the pressure of the fluid working medium in the high-pressure chamber is less than or equal to the pressure of the fluid working medium in the low-pressure chamber.

[0011] As a preferred solution for the method for predicting the performance of high-pressure fluid expansion ejection, in the process of obtaining the structural parameters of the ejection device and the initial thermophysical parameters of the fluid working medium filled in the high- and low-pressure chambers by setting measurement tools and setting sensors, the structural parameters of the ejection device include: the initial volume of the high- and low-pressure chambers, the cross-sectional area of ​​the valve connecting the high- and low-pressure chambers, the cross-sectional area of ​​the launch tube, the maximum movement stroke of the target load in the launch tube, the launch angle, and the load mass;

[0012] The initial thermophysical parameters of the fluid working medium filled in the high-pressure chamber and the low-pressure chamber include: the initial pressure and initial temperature of the fluid working medium.

[0013] As a preferred method for predicting the expansion ejection performance of high-pressure fluid, in the process of calculating the working fluid density and specific internal energy of the high- and low-pressure chamber fluid working fluids, the time change rate of the working fluid density in the high-pressure chamber is calculated as follows:

[0014]

[0015] Where, ρ H is the working fluid density in the high-pressure chamber; V H is the volume of the high-pressure chamber; t is time; Q m It is the mass flow rate per unit time of the fluid working medium flowing from the high-pressure chamber into the low-pressure chamber through the connecting valve;

[0016] The time rate of change of the specific internal energy of the fluid working medium in the high-pressure chamber is calculated as follows:

[0017]

[0018] Where u H h is the specific internal energy of the working fluid in the high-pressure chamber; His the specific enthalpy of the working fluid in the high-pressure chamber;

[0019] The time change rate of the working medium density of the low-pressure chamber fluid is calculated as follows:

[0020]

[0021]

[0022] Where, ρ L is the working fluid density in the low-pressure chamber; V L0 is the initial volume of the low-pressure chamber; S t is the cross-sectional area of ​​the launch tube; l is the target load displacement; v Load is the target load speed;

[0023] The time rate of change of the specific internal energy of the fluid working medium in the low-pressure chamber is calculated as follows:

[0024]

[0025] Where u L is the specific internal energy of the working fluid in the low-pressure chamber; p L is the low pressure chamber pressure.

[0026] As a preferred method for predicting the expansion ejection performance of high-pressure fluid, in the process of calculating the saturation point specific internal energy of the fluid working medium, when the working medium phase is just at the dew point line (or bubble point line), the saturation temperature T satur and saturated gas (or saturated liquid) density ρ satur Satisfy the conditions that the Gibbs free energy g and pressure p are equal, namely:

[0027] g(T satur ,ρ in )=g(T satur ,ρ satur )

[0028] p(T satur ,ρ in )=p(T satur ,ρ satur )

[0029] Where g(T,ρ) and p(T,ρ) are the functions of the specific Gibbs free energy g and pressure p with the working fluid temperature T and density ρ as independent variables, respectively. They have specific forms depending on the working fluid state equation adopted.

[0030] Working fluid density ρ in The corresponding saturation point is the internal energy u satur The calculation formula is:

[0031] u satur =u(T satur ,ρin )

[0032] Where u(T,ρ) is a function of the specific internal energy u with the working fluid temperature T and density ρ as independent variables, and has a specific form depending on the working fluid state equation used.

[0033] As a preferred method for predicting the performance of high-pressure fluid expansion ejection, in the process of calculating and obtaining the thermophysical parameters of the fluid working medium in the preset phase state, when the fluid working medium has a specific internal energy u in ≥u satur When the fluid is in a single phase such as supercritical state, liquid state or gas state, the calculation formula for the thermophysical parameters of the fluid is:

[0034] p=p(ρ in ,u in )

[0035] T=T(ρ in ,u in )

[0036] h=h(ρ in ,u in )

[0037] Where p(T,u), T(ρ,u) and h(ρ,u) are respectively functions of pressure p, temperature T and specific enthalpy h with working fluid density ρ and specific internal energy u as independent variables, and they have specific forms depending on the working fluid state equation adopted;

[0038] When the fluid working medium has a higher internal energy than u in <u satur When , the working fluid is in gas-liquid equilibrium state, the corresponding saturated liquid and saturated gas's specific Gibbs free energy g, pressure p, specific internal energy u and density ρ satisfy the following formula:

[0039] g(T,ρ liquid )=g(T,ρ vapor )

[0040] p(T,ρ liquid )=p(T,ρ vapor )

[0041] x liquid u(T,ρ liquid )+x vapor u(T,ρ vapor )=u in

[0042]

[0043] h=x liquid h(T,ρ liquid )+x vapor h(T,ρvapor )

[0044] Where u(T,ρ) is a function of the specific internal energy u with the working fluid temperature T and density ρ as independent variables, which has a specific form depending on the working fluid state equation adopted; ρ liquid and ρ vapor are the densities of saturated liquid and saturated gas respectively; x liquid and x vapor Respectively represent the mass fractions of the liquid phase and gas phase in the working fluid, and x liquid +x vapor =1;

[0045] By solving the satisfied formula, we can obtain the temperature T and saturation density ρ of the fluid working medium. liquid and ρ vapor and phase mass fraction x vapor and x liquid , pressure p, working fluid specific enthalpy h thermal physical parameters.

[0046] In a second aspect, the present invention further provides a high-pressure fluid expansion ejection performance prediction device, based on the above high-pressure fluid expansion ejection performance prediction method, comprising:

[0047] The initial parameter and calculation parameter acquisition module is used to obtain the structural parameters of the ejection device and the initial thermophysical parameters of the fluid working medium filled in the high and low pressure chambers by setting measurement tools and setting sensors; set the fluid working medium state equation, equation parameters and coefficients in the calculation process;

[0048] The working fluid physical property and target load motion state calculation module is used to calculate the working fluid density and specific internal energy of the fluid working fluid in the high and low pressure chambers through the set fluid working fluid state equation; and calculate the displacement and velocity of the target load through the target load motion state calculation equation;

[0049] The working fluid phase judgment and thermophysical property calculation module is used to calculate and obtain the saturation point specific internal energy of the fluid working fluid, judge the phase state of the fluid working fluid based on the saturation point specific internal energy, and calculate and obtain the thermophysical property parameters of the fluid working fluid in a preset phase state;

[0050] The cyclic solution calculation module is used to select a set time step and set a numerical solution strategy, perform iterative calculations through the fluid working medium state equation and the target load motion state calculation equation, and obtain the thermophysical parameters of the fluid working medium in the high-pressure and low-pressure chambers and the real-time motion state of the target load during the ejection process; when the displacement of the target load reaches the maximum motion stroke in the launch tube or the pressure of the fluid working medium in the high-pressure chamber is less than or equal to the pressure of the fluid working medium in the low-pressure chamber, the iterative calculation process ends.

[0051] As a preferred embodiment of the high-pressure fluid expansion ejection performance prediction device, in the initial parameter and calculation parameter acquisition module, in the process of obtaining the structural parameters of the ejection device and the initial thermophysical parameters of the fluid working medium filled in the high- and low-pressure chambers by setting the measurement tool and setting the sensor, the structural parameters of the ejection device include: the initial volume of the high- and low-pressure chambers, the cross-sectional area of ​​the valve connecting the high- and low-pressure chambers, the cross-sectional area of ​​the launch tube, the maximum movement stroke of the target load in the launch tube, the launch angle, and the load mass;

[0052] The initial thermophysical parameters of the fluid working medium filled in the high-pressure chamber and the low-pressure chamber include: the initial pressure and initial temperature of the fluid working medium.

[0053] As a preferred embodiment of the high-pressure fluid expansion ejection performance prediction device, in the working fluid physical property and target load motion state calculation module, in the process of calculating the working fluid density and specific internal energy of the high- and low-pressure chamber fluid working fluids, the time change rate of the working fluid density in the high-pressure chamber is calculated as follows:

[0054]

[0055] Where, ρ H is the working fluid density in the high-pressure chamber; V H is the volume of the high-pressure chamber; t is time; Q m It is the mass flow rate per unit time of the fluid working medium flowing from the high-pressure chamber into the low-pressure chamber through the connecting valve;

[0056] The time rate of change of the specific internal energy of the fluid working medium in the high-pressure chamber is calculated as follows:

[0057]

[0058] Where u H h is the specific internal energy of the working fluid in the high-pressure chamber; H is the specific enthalpy of the working fluid in the high-pressure chamber;

[0059] The time change rate of the working medium density of the low-pressure chamber fluid is calculated as follows:

[0060]

[0061]

[0062] Where, ρ L is the working fluid density in the low-pressure chamber; V L0 is the initial volume of the low-pressure chamber; S t is the cross-sectional area of ​​the launch tube; l is the target load displacement; v Load is the target load speed;

[0063] The time rate of change of the specific internal energy of the fluid working medium in the low-pressure chamber is calculated as follows:

[0064]

[0065] Where u L is the specific internal energy of the working fluid in the low-pressure chamber; p L is the low pressure chamber pressure.

[0066] As a preferred solution of the high-pressure fluid expansion ejection performance prediction device, in the working medium phase judgment and thermophysical property calculation module, in the process of calculating the saturation point specific internal energy of the fluid working medium, when the working medium phase is just at the dew point line (or bubble point line), the saturation temperature T satur and saturated gas (or saturated liquid) density ρ satur Satisfy the conditions that the Gibbs free energy g and pressure p are equal, namely:

[0067] g(T satur ,ρ in )=g(T satur ,ρ satur )

[0068] p(T satur ,ρ in )=p(T satur ,ρ satur )

[0069] Where g(T,ρ) and p(T,ρ) are the functions of the specific Gibbs free energy g and pressure p with the working fluid temperature T and density ρ as independent variables, respectively. They have specific forms depending on the working fluid state equation adopted.

[0070] Working fluid density ρ in The corresponding saturation point is the internal energy u satur The calculation formula is:

[0071] u satur =u(T satur ,ρ in )

[0072] Where u(T,ρ) is a function of the specific internal energy u with the working fluid temperature T and density ρ as independent variables, and has a specific form depending on the working fluid state equation used.

[0073] As a preferred solution of the high-pressure fluid expansion ejection performance prediction device, in the working medium phase judgment and thermal property calculation module, in the process of calculating and obtaining the thermal property parameters of the fluid working medium in the preset phase state, when the fluid working medium has a specific internal energy u in ≥u satur When the fluid is in a single phase such as supercritical state, liquid state or gas state, the calculation formula for the thermophysical parameters of the fluid is:

[0074] p=p(ρ in ,uin )

[0075] T=T(ρ in ,u in )

[0076] h=h(ρ in ,u in )

[0077] Where p(T,u), T(ρ,u) and h(ρ,u) are respectively functions of pressure p, temperature T and specific enthalpy h with working fluid density ρ and specific internal energy u as independent variables, and they have specific forms depending on the working fluid state equation adopted;

[0078] When the fluid working medium has a higher internal energy than u in <u satur When , the working fluid is in gas-liquid equilibrium state, the corresponding saturated liquid and saturated gas's specific Gibbs free energy g, pressure p, specific internal energy u and density ρ satisfy the following formula:

[0079] g(T,ρ liquid )=g(T,ρ vapor )

[0080] p(T,ρ liquid )=p(T,ρ vapor )

[0081] x liquid u(T,ρ liquid )+x vapor u(T,ρ vapor )=u in

[0082]

[0083] h=x liquid h(T,ρ liquid )+x vapor h(T,ρ vapor )

[0084] Where u(T,ρ) is a function of the specific internal energy u with the working fluid temperature T and density ρ as independent variables, which has a specific form depending on the working fluid state equation adopted; ρ liquid and ρ vapor are the densities of saturated liquid and saturated gas respectively; x liquid and x vapor Respectively represent the mass fractions of the liquid phase and gas phase in the working fluid, and x liquid +x vapor =1;

[0085] By solving the satisfied formula, we can obtain the temperature T and saturation density ρ of the fluid working medium. liquid and ρvapor and phase mass fraction x vapor and x liquid , pressure p, working fluid specific enthalpy h thermal physical parameters.

[0086] In a third aspect, the present invention provides a storage medium storing a program code for a high-pressure fluid expansion ejection performance prediction method, wherein the program code includes instructions for executing the high-pressure fluid expansion ejection performance prediction method of the first aspect or any possible implementation thereof.

[0087] In a fourth aspect, the present invention provides an electronic device comprising: a memory and a processor; the processor and the memory communicate with each other via a bus; the memory stores program instructions executable by the processor, and the processor calls the program instructions to execute the high-pressure fluid expansion ejection performance prediction method of the first aspect or any possible implementation thereof.

[0088] The present invention has the following advantages: obtaining structural parameters of the ejection device and initial thermophysical parameters of the fluid working medium filled in the high- and low-pressure chambers by setting measurement tools and setting sensors; setting the fluid working medium state equation, equation parameters and coefficients in the calculation process; calculating and obtaining the working medium density and specific internal energy of the fluid working medium in the high- and low-pressure chambers by using the set fluid working medium state equation; calculating and obtaining the displacement and velocity of the target load by using the target load motion state calculation equation; calculating and obtaining the saturation point specific internal energy of the fluid working medium, and judging the phase state of the fluid working medium by using the saturation point specific internal energy; calculating and obtaining the thermophysical parameters of the fluid working medium in a preset phase state; selecting a set time step and a set numerical solution strategy, and iteratively calculating by using the fluid working medium state equation and the target load motion state calculation equation to obtain the thermophysical parameters of the fluid working medium in the high- and low-pressure chambers and the real-time motion state of the target load during the ejection process; and terminating the iterative calculation process when the target load displacement reaches the maximum motion stroke in the launch tube or the pressure of the fluid working medium in the high-pressure chamber is less than or equal to the pressure of the fluid working medium in the low-pressure chamber. The present invention has strong versatility and is applicable to the performance prediction of ejection processes of traditional high-pressure fluids such as nitrogen and air that maintain a single phase during the ejection process, as well as the performance prediction of ejection processes of new fluids that may transition from a single phase to a two-phase equilibrium state during the ejection process. Using the density and specific internal energy of the fluid as independent input parameters, the phase state of the fluid is determined and the relevant thermophysical parameters are calculated. This method is highly applicable to state equations of various fluids. The present invention can concisely and intuitively obtain the dynamic thermophysical parameters of the high- and low-pressure chamber fluids and the real-time motion state of the target load during the expansion and ejection process of a high-pressure fluid, significantly saving experimental costs and providing a reference basis for the development and design of related high-pressure fluid expansion and ejection devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0090] The structures, proportions, sizes, etc. illustrated in this specification are intended solely to complement the contents disclosed herein and to facilitate understanding and reading by persons skilled in the art. They are not intended to limit the conditions under which the present invention may be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportions, or adjustments in sizes, without affecting the efficacy and objectives of the present invention, shall remain within the scope of the technical contents disclosed herein.

[0091] Figure 1 This is a schematic flow chart of the method for predicting the ejection performance of a high-pressure fluid expansion device provided in Example 1 of the present invention;

[0092] Figure 2 This is a schematic structural diagram of an ejection device in a possible embodiment provided in Example 1 of the present invention;

[0093] Figure 3 This is a flow chart of a performance prediction method in a possible embodiment provided in Example 1 of the present invention;

[0094] Figure 4 This is a schematic diagram of the high and low pressure chamber pressures calculated in a possible embodiment provided in Example 1 of the present invention;

[0095] Figure 5 This is a schematic diagram of the high and low pressure indoor temperatures calculated in a possible embodiment provided in Example 1 of the present invention;

[0096] Figure 6 This is a schematic diagram of the phase change results of the working fluid in the low-pressure chamber calculated in a possible embodiment provided in Example 1 of the present invention;

[0097] Figure 7 This is a schematic diagram of target load velocity and acceleration results calculated in a possible embodiment provided in Example 1 of the present invention;

[0098] Figure 8 This is a schematic diagram of target load displacement results calculated in a possible embodiment provided in Example 1 of the present invention;

[0099] Figure 9 This is a schematic diagram of the architecture of the high-pressure fluid expansion ejection performance prediction device provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0100] The following describes the implementation of the present invention using specific embodiments. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. Obviously, the embodiments described are only a portion of the present invention, not all of it. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0101] Example 1

[0102] See also Figure 1 Embodiment 1 of the present invention provides a method for predicting ejection performance of a high-pressure fluid expansion ejection ...

[0103] S1. Obtain the structural parameters of the ejection device and the initial thermophysical parameters of the fluid filling the high-pressure and low-pressure chambers by setting measurement tools and setting sensors; set the fluid state equation, equation parameters and coefficients in the calculation process;

[0104] S2. Calculate the density and specific internal energy of the fluid working medium in the high-pressure and low-pressure chambers using the set fluid working medium state equation; and calculate the displacement and velocity of the target load using the target load motion state calculation equation;

[0105] S3. Calculate and obtain the saturation point specific internal energy of the fluid working medium, and determine the phase state of the fluid working medium based on the saturation point specific internal energy; calculate and obtain the thermophysical property parameters of the fluid working medium in a preset phase state;

[0106] S4. Select a set time step and a set numerical solution strategy, perform iterative calculations using the fluid working medium state equation and the target load motion state calculation equation to obtain the thermophysical parameters of the fluid working medium in the high- and low-pressure chambers and the real-time motion state of the target load during the ejection process; the iterative calculation process ends when the target load displacement reaches the maximum motion stroke in the launch tube or the pressure of the fluid working medium in the high-pressure chamber is less than or equal to the pressure of the fluid working medium in the low-pressure chamber.

[0107] In this embodiment, the following assumptions are made in the process of calculating and obtaining relevant thermal properties and other parameters:

[0108] During the ejection process, the high and low pressure chambers of the ejection device are filled with the same fluid. At any moment, the fluid is evenly distributed in the high and low pressure chambers, and the thermophysical parameters are equal everywhere.

[0109] The ejection process takes a short time, and the heat exchange between the launch device and the surrounding environment is ignored;

[0110] Ignoring the mechanical energy and viscosity of the high-pressure fluid, the ejection device has good air tightness;

[0111] The process of the fluid in the high-pressure chamber flowing into the low-pressure chamber is a one-dimensional quasi-steady adiabatic isentropic process;

[0112] The cross-sectional area of ​​the bottom of the payload is equal to the cross-sectional area of ​​the launch tube.

[0113] In this embodiment, in step S1, in the process of obtaining the structural parameters of the ejection device and the initial thermophysical parameters of the fluid working medium filled in the high- and low-pressure chambers by setting the measuring tool and setting the sensor, the structural parameters of the ejection device include: the initial volume of the high- and low-pressure chambers, the cross-sectional area of ​​the valves connecting the high- and low-pressure chambers, the cross-sectional area of ​​the launch tube, the maximum movement stroke of the target load in the launch tube, the launch angle and the load mass; the initial thermophysical parameters of the fluid working medium filled in the high- and low-pressure chambers include: the initial pressure and initial temperature of the filling fluid working medium; the relevant coefficients in the calculation process include the flow coefficient of the connecting valve, the adiabatic index of the working medium and the friction coefficient between the target load and the launch tube.

[0114] The ejection mechanism's geometric parameters are measured on-site using volume and length measuring tools. High-pressure fluid filling parameters are measured using pressure sensors, temperature sensors, or other pressure, temperature, mass, and volume measuring tools. The connecting valve flow coefficient, the fluid adiabatic index, and the friction coefficient between the target payload and the launch tube are manually set based on relevant engineering experience.

[0115] In this embodiment, in step S2, in the process of calculating the working medium density and specific internal energy of the fluid working medium in the high-pressure chamber and the low-pressure chamber, the time change rate of the working medium density of the fluid working medium in the high-pressure chamber is calculated as follows:

[0116]

[0117] Where, ρ H is the working fluid density in the high-pressure chamber; V H is the volume of the high-pressure chamber; t is time; Q m It is the mass flow rate per unit time of the fluid working medium flowing from the high-pressure chamber into the low-pressure chamber through the connecting valve;

[0118] The time rate of change of the specific internal energy of the fluid working medium in the high-pressure chamber is calculated as follows:

[0119]

[0120] Where u H h is the specific internal energy of the working fluid in the high-pressure chamber; H is the specific enthalpy of the working fluid in the high-pressure chamber;

[0121] The time change rate of the working medium density of the low-pressure chamber fluid is calculated as follows:

[0122]

[0123]

[0124] Where, ρ L is the working fluid density in the low-pressure chamber; V L0 is the initial volume of the low-pressure chamber; S t is the cross-sectional area of ​​the launch tube; l is the target load displacement; v Load is the target load speed;

[0125] The time rate of change of the specific internal energy of the fluid working medium in the low-pressure chamber is calculated as follows:

[0126]

[0127] Where u L is the specific internal energy of the working fluid in the low-pressure chamber; p L is the low pressure chamber pressure.

[0128] Specifically, the time rate of change of target load velocity is calculated as follows:

[0129]

[0130] F Load =(p L -p amb )S t -m Load g sinα-μ f m Load g cosα (7)

[0131] Where m Load is the load mass; F Load is the resultant external force acting on the load; p amb is the external atmospheric pressure; g is the acceleration of gravity; α is the launch angle; μ f is the friction coefficient between the target payload and the launch tube.

[0132] According to the state of the working fluid in the high and low pressure chambers, considering the subsonic and sonic flow conditions, based on the adiabatic isentropic assumption, the working fluid mass flow rate Q flowing from the high pressure chamber to the low pressure chamber at a certain moment is m Calculate according to formula (8):

[0133]

[0134] Where μ χ is the flow coefficient of the connecting valve; S c is the cross-sectional area of ​​the connecting valve; κ is the adiabatic index of the working fluid.

[0135] Assume that at a certain time t during the ejection process, the physical properties of the high- and low-pressure chamber working fluids, the motion state of the target load, and the other parameters in equations (1) to (8) have been calculated. Then, the physical properties of the high- and low-pressure chamber working fluids and the motion state of the target load at time t+Δt can be calculated by simultaneously solving the first-order ordinary differential equations: equations (1) to (6) using numerical integration methods such as the Euler method, the Runge-Kutta method, and the finite difference method, where Δt is the time step.

[0136] In this embodiment, in step S3, when calculating the saturation point specific internal energy of the fluid working medium, when the working medium phase is just at the dew point line (or bubble point line), the saturation temperature T satur and saturated gas (or saturated liquid) density ρ satur Satisfy the conditions that the Gibbs free energy g and pressure p are equal, namely:

[0137] g(T satur ,ρ in )=g(T satur ,ρ satur ) (9a)

[0138] p(T satur ,ρ in )=p(T satur ,ρ satur ) (9b)

[0139] Where g(T,ρ) and p(T,ρ) are the functions of the specific Gibbs free energy g and pressure p with the working fluid temperature T and density ρ as independent variables, respectively. They have specific forms depending on the working fluid state equation adopted.

[0140] Working fluid density ρ in The corresponding saturation point is the internal energy u satur The calculation formula is:

[0141] u satur =u(T satur ,ρ in ) (10)

[0142] Where u(T,ρ) is a function of the specific internal energy u with the working fluid temperature T and density ρ as independent variables, and has a specific form depending on the working fluid state equation used.

[0143] In this embodiment, in step S3, when calculating and obtaining the thermophysical parameters of the fluid working medium in the preset phase state, the fluid working medium has a specific internal energy u in ≥u satur When the fluid is in a single phase such as supercritical state, liquid state or gas state, the calculation formula for the thermophysical parameters of the fluid is:

[0144] p=p(ρ in ,uin ) (11a)

[0145] T=T(ρ in ,u in ) (11b)

[0146] h=h(ρ in ,u in ) (11c)

[0147] Where p(T,u), T(ρ,u) and h(ρ,u) are respectively functions of pressure p, temperature T and specific enthalpy h with working fluid density ρ and specific internal energy u as independent variables, and they have specific forms depending on the working fluid state equation adopted;

[0148] When the fluid working medium has a higher internal energy than u in <u satur When , the working fluid is in gas-liquid equilibrium state, the corresponding saturated liquid and saturated gas's specific Gibbs free energy g, pressure p, specific internal energy u and density ρ satisfy the following formula:

[0149] g(T,ρ liquid )=g(T,ρ vapor ) (12a)

[0150] p(T,ρ liquid )=p(T,ρ vapor ) (12b)

[0151] x liquid u(T,ρ liquid )+x vapor u(T,ρ vapor )=u in (12c)

[0152]

[0153] h=x liquid h(T,ρ liquid )+x vapor h(T,ρ vapor ) (13)

[0154] Where u(T,ρ) is a function of the specific internal energy u with the working fluid temperature T and density ρ as independent variables, which has a specific form depending on the working fluid state equation adopted; ρ liquid and ρ vapor are the densities of saturated liquid and saturated gas respectively; x liquid and x vapor Respectively represent the mass fractions of the liquid phase and gas phase in the working fluid, and x liquid +x vapor =1;

[0155] By solving the satisfied formula, we can obtain the temperature T and saturation density ρ of the fluid working medium. liquid and ρ vapor and phase mass fraction x vapor and x liquid , pressure p, working fluid specific enthalpy h thermal physical parameters.

[0156] In this embodiment, in step S4, a set time step and a set numerical solution strategy are selected, and iterative calculations are performed using the fluid working medium state equation and the target load motion state calculation equation to obtain the thermophysical parameters of the fluid working medium in the high- and low-pressure chambers and the real-time motion state of the target load during the ejection process; when the target load displacement reaches the maximum motion stroke in the launch tube or the pressure of the fluid working medium in the high-pressure chamber is less than or equal to the pressure of the fluid working medium in the low-pressure chamber, the iterative calculation process ends.

[0157] Specifically, an appropriate time step Δt and numerical solution algorithm are selected, and steps S2 and S3 are repeated to gradually calculate the thermophysical properties of the high- and low-pressure chamber working fluids and the real-time motion state of the target payload during the launch process. The calculation process ends when the target payload displacement reaches its maximum range within the launch tube or the high-pressure chamber working fluid pressure is less than or equal to the low-pressure chamber working fluid pressure.

[0158] In a possible embodiment, a specific example of performance prediction of a high-pressure fluid expansion ejection device is provided as follows:

[0159] like Figure 2 As shown in Figure 1, a high-pressure fluid expansion ejection device. At the start of the launch, the pressure of the fluid filled in the high-pressure chamber is 40 MPa, the temperature is 407.53 K (134.38 ° C), and the mass of the fluid is 2.6 kg. The volume of the high-pressure chamber is 4 L, the initial volume of the low-pressure chamber is 2 L, and the cross-sectional area of ​​the connecting valve is 3.14×10 -4 m 2 The maximum travel of the target payload in the launch tube is 2.5m, and the cross-sectional area of ​​the launch tube is 3.14×10 -2 m 2 The launch angle is 45° and the payload mass is 100 kg. The goal is to calculate the changes in the thermophysical properties of the high- and low-pressure chambers of the ejection device and the target payload's motion from the start of launch until the target payload reaches its maximum displacement within the launch tube.

[0160] Its performance indicates the process of Figure 3 The specific steps are as follows:

[0161] T1. Obtain initial parameters and determine calculation parameters;

[0162] The launch parameters of the ejection device measured on site or obtained in advance are as follows: the initial volumes of the high and low pressure chambers are 4L and 2L respectively; the cross-sectional area of ​​the high and low pressure chamber connecting valves is 3.14×10 -4 m 2 The cross-sectional area of ​​the launch tube is 3.14×10 -2 m 2 The maximum movement range of the target payload in the launch tube is 2.5m, the launch angle is 45°, and the load mass is 100kg.

[0163] According to on-site measurements at the work site, at the beginning of the launch, the pressure of a certain fluid filled in the high-pressure chamber was 40MPa, the temperature was 407.53K (134.38℃), the mass of the fluid was 2.6kg, and the pressure and temperature of the fluid in the low-pressure chamber were the same as the ambient atmospheric pressure and temperature.

[0164] The state equation of the fluid working medium is determined to be a state equation based on Helmholtz free energy, and relevant parameters of the state equation are obtained.

[0165] The flow coefficient of the connecting valve in the calculation process is set to 0.8, the working fluid adiabatic index is set to 1.3, and the friction coefficient between the target load and the launch tube is set to 0.2.

[0166] T2. Calculate the physical properties of the working fluid in the high and low pressure chambers and the motion state of the target load;

[0167] The time step Δt is selected as 1ms, and the Runge-Kutta method is used to calculate the first-order ordinary differential equation system. The density and specific internal energy of the working fluid in the high and low pressure chambers, and the displacement and velocity of the target load motion are obtained through the calculation of equations (1)-(8) in step S2.

[0168] T3. Determine the phase state of the working fluid and calculate its remaining thermophysical parameters;

[0169] By calculating equations (9)-(13) in step S3, we can obtain the working fluid temperature T and saturation density ρ liquid and ρ vapor and phase mass fraction x vapor and x liquid , pressure p, working fluid specific enthalpy h thermal physical parameters.

[0170] T4, repeat steps T2 and T3 until the target load reaches its maximum motion range in the launch tube or the working fluid pressure in the high-pressure chamber is less than or equal to the working fluid pressure in the low-pressure chamber, and the solution ends. The calculated high-pressure and low-pressure chamber pressure, temperature, and phase state time history curves are as follows: Figure 4 、 Figure 5 and Figure 6 The target load motion speed and acceleration are calculated as follows: Figure 7 As shown, the displacement of the target load is Figure 8 shown.

[0171] This embodiment allows for the concise and intuitive calculation of the dynamic thermophysical parameters of the high- and low-pressure chamber working fluids and the real-time motion state of the target load during the expansion and ejection of the high-pressure fluid working fluid in a manner that requires less storage space and computing power. In particular, the phase changes of the fluid working fluid during the ejection process can be clearly seen.

[0172] In summary, the present invention obtains the structural parameters of the ejection device and the initial thermophysical parameters of the fluid working medium filled in the high and low pressure chambers by setting measurement tools and setting sensors; sets the fluid working medium state equation, equation parameters and coefficients in the calculation process; calculates the working medium density and specific internal energy of the fluid working medium in the high and low pressure chambers through the set fluid working medium state equation; calculates the displacement and velocity of the target load through the target load motion state calculation equation; calculates the saturation point specific internal energy of the fluid working medium, and determines the phase state of the fluid working medium through the saturation point specific internal energy; calculates the thermophysical parameters of the fluid working medium in a preset phase state; selects a set time step and a set numerical solution strategy, and iteratively calculates the thermophysical parameters of the fluid working medium in the high and low pressure chambers and the real-time motion state of the target load during the ejection process through the fluid working medium state equation and the target load motion state calculation equation; the iterative calculation process ends when the target load displacement reaches the maximum motion stroke in the launch tube or the pressure of the fluid working medium in the high pressure chamber is less than or equal to the pressure of the fluid working medium in the low pressure chamber. The present invention has strong versatility and is applicable to the performance prediction of ejection processes of traditional high-pressure fluids such as nitrogen and air that maintain a single phase during the ejection process, as well as the performance prediction of ejection processes of new fluids that may transition from a single phase to a two-phase equilibrium state during the ejection process. Using the density and specific internal energy of the fluid as independent input parameters, the phase state of the fluid is determined and the relevant thermophysical parameters are calculated. This method is highly applicable to state equations of various fluids. The present invention can concisely and intuitively obtain the dynamic thermophysical parameters of the high- and low-pressure chamber fluids and the real-time motion state of the target load during the expansion and ejection process of a high-pressure fluid, significantly saving experimental costs and providing a reference basis for the development and design of related high-pressure fluid expansion and ejection devices.

[0173] It should be noted that the method of the embodiments of the present disclosure can be performed by a single device, such as a computer or server. The method of the embodiments of the present disclosure can also be applied in a distributed scenario, where multiple devices cooperate to perform the method. In such a distributed scenario, one of the multiple devices may only perform one or more steps of the method of the embodiments of the present disclosure, and the multiple devices will interact with each other to complete the method.

[0174] It should be noted that the above description is limited to some embodiments of the present disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in an order different from that described in the above embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0175] Example 2

[0176] See also Figure 9 Embodiment 2 of the present invention further provides a high-pressure fluid expansion ejection performance prediction device, comprising:

[0177] The initial parameter and calculation parameter acquisition module 001 is used to obtain the structural parameters of the ejection device and the initial thermophysical parameters of the fluid filling the high and low pressure chambers by setting measurement tools and setting sensors; set the fluid state equation, equation parameters and coefficients in the calculation process;

[0178] The working fluid physical property and target load motion state calculation module 002 is used to calculate the working fluid density and specific internal energy of the fluid working fluid in the high and low pressure chambers by using the set fluid working fluid state equation; and calculate the displacement and velocity of the target load by using the target load motion state calculation equation;

[0179] The working medium phase judgment and thermophysical property calculation module 003 is used to calculate and obtain the saturation point specific internal energy of the fluid working medium, and judge the phase state of the fluid working medium based on the saturation point specific internal energy; and calculate and obtain the thermophysical property parameters of the fluid working medium in a preset phase state;

[0180] The loop solution calculation module 004 is used to select a set time step and set a numerical solution strategy, and perform iterative calculations using the fluid working medium state equation and the target load motion state calculation equation to obtain the thermophysical parameters of the fluid working medium in the high and low pressure chambers and the real-time motion state of the target load during the ejection process. The iterative calculation process ends when the target load displacement reaches the maximum motion range in the launch tube or the pressure of the fluid working medium in the high pressure chamber is less than or equal to the pressure of the fluid working medium in the low pressure chamber.

[0181] In this embodiment, in the initial parameter and calculation parameter acquisition module 001, in the process of obtaining the structural parameters of the ejection device and the initial thermophysical parameters of the fluid filling the high- and low-pressure chambers by setting the measurement tool and setting the sensor, the structural parameters of the ejection device include: the initial volume of the high- and low-pressure chambers, the cross-sectional area of ​​the high- and low-pressure chamber connecting valves, the cross-sectional area of ​​the launch tube, the maximum movement stroke of the target load in the launch tube, the launch angle, and the load mass;

[0182] The initial thermophysical parameters of the fluid working medium filled in the high-pressure chamber and the low-pressure chamber include: the initial pressure and initial temperature of the fluid working medium.

[0183] In this embodiment, in the working fluid physical property and target load motion state calculation module 002, in the process of calculating the working fluid density and specific internal energy of the high- and low-pressure chamber fluid working fluids, the time change rate of the working fluid density in the high-pressure chamber working fluid is calculated as follows:

[0184]

[0185] Where, ρ H is the working fluid density in the high-pressure chamber; V H is the volume of the high-pressure chamber; t is time; Q m It is the mass flow rate per unit time of the fluid working medium flowing from the high-pressure chamber into the low-pressure chamber through the connecting valve;

[0186] The time rate of change of the specific internal energy of the fluid working medium in the high-pressure chamber is calculated as follows:

[0187]

[0188] Where u H h is the specific internal energy of the working medium in the high-pressure chamber; H is the specific enthalpy of the working fluid in the high-pressure chamber;

[0189] The time change rate of the working medium density of the low-pressure chamber fluid is calculated as follows:

[0190]

[0191]

[0192] Where, ρ L is the working fluid density in the low-pressure chamber; V L0 is the initial volume of the low-pressure chamber; S t is the cross-sectional area of ​​the launch tube; l is the target load displacement; v Load is the target load speed;

[0193] The time rate of change of the specific internal energy of the fluid working medium in the low-pressure chamber is calculated as follows:

[0194]

[0195] Where u L is the specific internal energy of the working fluid in the low-pressure chamber; p L is the low pressure chamber pressure.

[0196] In this embodiment, in the working medium phase judgment and thermophysical property calculation module 003, when calculating the saturation point specific internal energy of the fluid working medium, when the working medium phase is just at the dew point line (or bubble point line), the saturation temperature Tsatur and saturated gas (or saturated liquid) density ρ satur Satisfy the conditions that the Gibbs free energy g and pressure p are equal, namely:

[0197] g(T satur ,ρ in )=g(T satur ,ρ satur )

[0198] p(T satur ,ρ in )=p(T satur ,ρ satur )

[0199] Where g(T,ρ) and p(T,ρ) are the functions of the specific Gibbs free energy g and pressure p with the working fluid temperature T and density ρ as independent variables, respectively. They have specific forms depending on the working fluid state equation adopted.

[0200] Working fluid density ρ in The corresponding saturation point is the internal energy u satur The calculation formula is:

[0201] u satur =u(T satur ,ρ in )

[0202] Where u(T,ρ) is a function of the specific internal energy u with the working fluid temperature T and density ρ as independent variables, and has a specific form depending on the working fluid state equation used.

[0203] In this embodiment, in the working medium phase judgment and thermophysical property calculation module 003, in the process of calculating and obtaining the thermophysical property parameters of the fluid working medium in the preset phase, when the fluid working medium has a higher internal energy than the internal energy u in ≥u satur When the fluid is in a single phase such as supercritical state, liquid state or gas state, the calculation formula for the thermophysical parameters of the fluid is:

[0204] p=p(ρ in ,u in )

[0205] T=T(ρ in ,u in )

[0206] h=h(ρ in ,u in )

[0207] Where p(T,u), T(ρ,u) and h(ρ,u) are respectively functions of pressure p, temperature T and specific enthalpy h with working fluid density ρ and specific internal energy u as independent variables, and they have specific forms depending on the working fluid state equation adopted;

[0208] When the fluid working medium has a higher internal energy than u in <u satur When , the working fluid is in gas-liquid equilibrium state, the corresponding saturated liquid and saturated gas's specific Gibbs free energy g, pressure p, specific internal energy u and density ρ satisfy the following formula:

[0209] g(T,ρ liquid )=g(T,ρ vapor )

[0210] p(T,ρ liquid )=p(T,ρ vapor )

[0211] x liquid u(T,ρ liquid )+x vapor u(T,ρ vapor )=u in

[0212]

[0213] h=x liquid h(T,ρ liquid )+x vapor h(T,ρ vapor )

[0214] Where u(T,ρ) is a function of the specific internal energy u with the working fluid temperature T and density ρ as independent variables, and it has a specific form depending on the working fluid state equation adopted; ρ liquid and ρ vapor are the densities of saturated liquid and saturated gas respectively; x liquid and x vapor represent the mass fractions of liquid and gas phase in the working fluid respectively, and x liquid +x vapor =1;

[0215] By solving the satisfied formula, we can obtain the temperature T and saturation density ρ of the fluid working medium. liquid and ρ vapor and phase mass fraction x vapor and x liquid , pressure p, working fluid specific enthalpy h thermal physical parameters.

[0216] It should be noted that the information interaction, execution process, etc. between the modules of the above-mentioned system are based on the same concept as the method embodiment in Example 1 of the present application, and the technical effects they bring are the same as those of the method embodiment of the present application. For specific contents, please refer to the description in the method embodiment shown above in the present application, and no further details will be given here.

[0217] Example 3

[0218] Embodiment 3 of the present invention provides a non-transitory computer-readable storage medium, in which the program code of the high-pressure fluid expansion ejection performance prediction method is stored. The program code includes instructions for executing the high-pressure fluid expansion ejection performance prediction method of embodiment 1 or any possible implementation thereof.

[0219] Computer-readable storage media can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives (SSDs)).

[0220] Example 4

[0221] Embodiment 4 of the present invention provides an electronic device, including: a memory and a processor;

[0222] The processor and the memory communicate with each other via a bus; the memory stores program instructions that can be executed by the processor, and the processor calls the program instructions to execute the high-pressure fluid expansion ejection performance prediction method of Example 1 or any possible implementation thereof.

[0223] Specifically, the processor can be implemented by hardware or by software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, etc.; when implemented by software, the processor can be a general-purpose processor, which is implemented by reading software code stored in a memory. The memory can be integrated into the processor or located outside the processor and exist independently.

[0224] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable systems. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode.

[0225] Obviously, those skilled in the art will appreciate that the various modules or steps of the present invention described above can be implemented using a general-purpose computing system. They can be centralized on a single computing system or distributed across a network of multiple computing systems. Alternatively, they can be implemented using program code executable by a computing system, and thus, they can be stored in a storage system and executed by the computing system. In some cases, the steps shown or described herein can be performed in a different order than that shown, or they can be fabricated into separate integrated circuit modules, or multiple modules or steps can be fabricated into a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0226] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made thereto. Therefore, such modifications and improvements, without departing from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A method for predicting ejection performance using high-pressure fluid expansion, characterized in that: include: The structural parameters of the ejection device and the initial thermophysical parameters of the fluid filling the high and low pressure chambers are obtained by setting measurement tools and setting sensors; Set the fluid working medium state equation, equation parameters and coefficients in the calculation process; The working medium density and specific internal energy of the working medium in the high-pressure and low-pressure chambers are calculated by using the set fluid working medium state equation; the displacement and velocity of the target load are calculated by using the target load motion state calculation equation; Calculating and obtaining the saturation point specific internal energy of the fluid working medium, and determining the phase state of the fluid working medium based on the saturation point specific internal energy; Calculate and obtain the thermophysical parameters of the fluid working medium in a preset phase state; A set time step and a set numerical solution strategy are selected, and iterative calculations are performed using the fluid working medium state equation and the target load motion state calculation equation to obtain the thermophysical parameters of the fluid working medium in the high- and low-pressure chambers and the real-time motion state of the target load during the ejection process; the iterative calculation process ends when the target load displacement reaches the maximum motion stroke in the launch tube or the pressure of the fluid working medium in the high-pressure chamber is less than or equal to the pressure of the fluid working medium in the low-pressure chamber.

2. The high-pressure fluid expansion ejection performance prediction method according to claim 1, characterized in that: In the process of obtaining the structural parameters of the ejection device and the initial thermophysical parameters of the fluid filling the high-pressure and low-pressure chambers by setting the measuring tools and setting the sensors, the structural parameters of the ejection device include: the initial volume of the high-pressure and low-pressure chambers, the cross-sectional area of ​​the valve connecting the high-pressure and low-pressure chambers, the cross-sectional area of ​​the launch tube, the maximum movement stroke of the target load in the launch tube, the launch angle and the load mass; The initial thermophysical parameters of the fluid working medium filled in the high-pressure chamber and the low-pressure chamber include: the initial pressure and initial temperature of the fluid working medium.

3. The high-pressure fluid expansion ejection performance prediction method according to claim 2, characterized in that: In the process of calculating the working medium density and specific internal energy of the high-pressure and low-pressure chamber fluid working medium, the time change rate of the working medium density of the high-pressure chamber fluid working medium is calculated as follows: Where, ρ H is the working fluid density in the high-pressure chamber; V H is the volume of the high-pressure chamber; t is time; Q m It is the mass flow rate per unit time of the fluid working medium flowing from the high-pressure chamber into the low-pressure chamber through the connecting valve; The time rate of change of the specific internal energy of the fluid working medium in the high-pressure chamber is calculated as follows: Where u H h is the specific internal energy of the working medium in the high-pressure chamber; H is the specific enthalpy of the working fluid in the high-pressure chamber; The time change rate of the working medium density of the low-pressure chamber fluid is calculated as follows: Where, ρ L is the working fluid density in the low-pressure chamber; V L0 is the initial volume of the low-pressure chamber; S t is the cross-sectional area of ​​the launch tube; l is the target load displacement; v Load is the target load speed; The time rate of change of the specific internal energy of the fluid working medium in the low-pressure chamber is calculated as follows: Where u L is the specific internal energy of the working fluid in the low-pressure chamber; p L is the low pressure chamber pressure.

4. The high-pressure fluid expansion ejection performance prediction method according to claim 3, characterized in that: In the process of calculating the saturation point specific internal energy of the fluid working medium, when the working medium phase is just at the dew point line or bubble point line, the saturation temperature T satur and the density of saturated gas or saturated liquid ρ satur Satisfy the conditions that the Gibbs free energy g and pressure p are equal, namely: g(T satur ,r in )=g(T satur ,r satur ) p(T satur ,r in )=p(T satur ,r satur ) Where g(T,ρ) and p(T,ρ) are the functions of the Gibbs free energy g and pressure p with the working fluid temperature T and density ρ as independent variables respectively; Working fluid density ρ in The corresponding saturation point is the internal energy u satur The calculation formula is: u satur =u(T satur ,ρ in ) Where u(T,ρ) is a function of the specific internal energy u with the working fluid temperature T and density ρ as independent variables.

5. The high-pressure fluid expansion ejection performance prediction method according to claim 4, characterized in that: In the process of calculating and obtaining the thermophysical parameters of the fluid working medium in the preset phase state, when the fluid working medium has a specific internal energy u in ≥u satur When the fluid is in a supercritical state, liquid or gaseous single phase, the calculation formula for the thermophysical parameters of the fluid is: p=p(ρ in ,u in ) T=T(ρ in ,u in ) h=h(ρ in ,he in ) Where p(T,u) is the function of pressure p with temperature T and specific internal energy u as independent variables, T(ρ,u) and h(ρ,u) are the functions of temperature T and specific enthalpy h with working fluid density ρ and specific internal energy u as independent variables, respectively. It has a specific form depending on the working fluid state equation adopted; When the fluid working medium has a higher internal energy than u in <u satur When , the working fluid is in gas-liquid equilibrium state, the corresponding saturated liquid and saturated gas's specific Gibbs free energy g, pressure p, specific internal energy u and density ρ satisfy the following formula: g(T,ρ liquid )=g(T,ρ vapor ) p(T,ρ liquid )=p(T,ρ vapor ) x liquid u(T,ρ liquid )+x vapor u(T,ρ vapor )=u in h=x liquid h(T,ρ liquid )+x vapor h(T,ρ vapor ) Where u(T,ρ) is a function of the specific internal energy u with the working fluid temperature T and density ρ as independent variables, which has a specific form depending on the working fluid state equation adopted; ρ liquid and ρ vapor are the densities of saturated liquid and saturated gas respectively; x liquid and x vapor represent the mass fractions of liquid and gas phase in the working fluid respectively, and x liquid +x vapor =1; By solving the satisfied formula, we can obtain the temperature T and saturation density ρ of the fluid working medium. liquid and ρ vapor and phase mass fraction x vapor and x liquid , pressure p, working fluid specific enthalpy h thermal physical parameters.

6. A high-pressure fluid expansion ejection performance prediction device, using any of the high-pressure fluid expansion ejection performance prediction methods of claims 1-5, characterized in that: include: The initial parameter and calculation parameter acquisition module is used to obtain the structural parameters of the ejection device and the initial thermal physical parameters of the fluid filling the high and low pressure chambers by setting measurement tools and setting sensors; Set the fluid working medium state equation, equation parameters and coefficients in the calculation process; The working fluid physical property and target load motion state calculation module is used to calculate the working fluid density and specific internal energy of the fluid working fluid in the high and low pressure chambers through the set fluid working fluid state equation; and calculate the displacement and velocity of the target load through the target load motion state calculation equation; The working medium phase state judgment and thermophysical property calculation module is used to calculate the saturation point specific internal energy of the fluid working medium and judge the phase state of the fluid working medium based on the saturation point specific internal energy; Calculate and obtain the thermophysical parameters of the fluid working medium in a preset phase state; The cyclic solution calculation module is used to select a set time step and set a numerical solution strategy, perform iterative calculations through the fluid working medium state equation and the target load motion state calculation equation, and obtain the thermophysical parameters of the fluid working medium in the high-pressure and low-pressure chambers and the real-time motion state of the target load during the ejection process; when the displacement of the target load reaches the maximum motion stroke in the launch tube or the pressure of the fluid working medium in the high-pressure chamber is less than or equal to the pressure of the fluid working medium in the low-pressure chamber, the iterative calculation process ends.

7. The high-pressure fluid expansion ejection performance prediction device according to claim 6, characterized in that: In the initial parameter and calculation parameter acquisition module, in the process of measuring and acquiring the structural parameters of the ejection device and the initial thermophysical parameters of the fluid filling the high- and low-pressure chambers by setting the measurement tool and setting the sensor, the structural parameters of the ejection device include: the initial volume of the high- and low-pressure chambers, the cross-sectional area of ​​the valve connecting the high- and low-pressure chambers, the cross-sectional area of ​​the launch tube, the maximum movement stroke of the target load in the launch tube, the launch angle, and the load mass; The initial thermophysical parameters of the fluid working medium filled in the high-pressure chamber and the low-pressure chamber include: the initial pressure and initial temperature of the fluid working medium.

8. The high-pressure fluid expansion ejection performance prediction device according to claim 7, characterized in that: In the working fluid physical property and target load motion state calculation module, in the process of calculating the working fluid density and specific internal energy of the high- and low-pressure chamber fluid working fluids, the time change rate of the working fluid density in the high-pressure chamber working fluid is calculated as follows: Where, ρ H is the working fluid density in the high-pressure chamber; V H is the volume of the high-pressure chamber; t is time; Q m It is the mass flow rate per unit time of the fluid working medium flowing from the high-pressure chamber into the low-pressure chamber through the connecting valve; The time rate of change of the specific internal energy of the fluid working medium in the high-pressure chamber is calculated as follows: Where u H h is the specific internal energy of the working medium in the high-pressure chamber; H is the specific enthalpy of the working fluid in the high-pressure chamber; The time change rate of the working medium density of the low-pressure chamber fluid is calculated as follows: Where, ρ L is the working fluid density in the low-pressure chamber; V L0 is the initial volume of the low-pressure chamber; S t is the cross-sectional area of ​​the launch tube; l is the target load displacement; v Load is the target load speed; The time rate of change of the specific internal energy of the fluid working medium in the low-pressure chamber is calculated as follows: Where u L is the specific internal energy of the working fluid in the low-pressure chamber; p L is the low pressure chamber pressure; In the working medium phase judgment and thermophysical property calculation module, when calculating the saturation point specific internal energy of the fluid working medium, when the working medium phase is just at the dew point line or bubble point line, the saturation temperature T satur and the density of saturated gas or saturated liquid ρ satur Satisfy the conditions that the Gibbs free energy g and pressure p are equal, namely: g(T satur ,r in )=g(T satur ,r satur ) p(T satur ,r in )=p(T satur ,r satur ) Where g(T,ρ) and p(T,ρ) are the functions of the Gibbs free energy g and pressure p with the working fluid temperature T and density ρ as independent variables respectively; Working fluid density ρ in The corresponding saturation point is the internal energy u satur The calculation formula is: u satur =u(T satur ,ρ in ) Where u(T,ρ) is a function of the specific internal energy u with the working fluid temperature T and density ρ as independent variables, and it has a specific form depending on the working fluid state equation adopted; In the working medium phase judgment and thermophysical property calculation module, when calculating and obtaining the thermophysical property parameters of the fluid working medium in the preset phase state, the fluid working medium has a specific internal energy u in ≥u satur When the fluid is in a supercritical state, liquid or gaseous single phase, the calculation formula for the thermophysical parameters of the fluid is: p=p(ρ in ,u in ) T=T(ρ in ,u in ) h=h(ρ in ,he in ) Where p(T,u) is the function of pressure p with temperature T and specific internal energy u as independent variables, T(ρ,u) and h(ρ,u) are the functions of temperature T and specific enthalpy h with working fluid density ρ and specific internal energy u as independent variables respectively; When the fluid working medium has a higher internal energy than u in <u satur When , the working fluid is in gas-liquid equilibrium state, the corresponding saturated liquid and saturated gas's specific Gibbs free energy g, pressure p, specific internal energy u and density ρ satisfy the following formula: g(T,ρ liquid )=g(T,ρ vapor ) p(T,ρ liquid )=p(T,ρ vapor ) x liquid u(T,ρ liquid )+x vapor u(T,ρ vapor )=u in h=x liquid h(T,ρ liquid )+x vapor h(T,ρ vapor ) Where u(T,ρ) is a function of the specific internal energy u with the working fluid temperature T and density ρ as independent variables, which has a specific form depending on the working fluid state equation adopted; ρ liquid and ρ vapor are the densities of saturated liquid and saturated gas respectively; x liquid and x vapor represent the mass fractions of liquid and gas phase in the working fluid respectively, and x liquid +x vapor =1; By solving the satisfied formula, we can obtain the temperature T and saturation density ρ of the fluid working medium. liquid and ρ vapor and phase mass fraction x vapor and x liquid , pressure p, working fluid specific enthalpy h thermal physical parameters.

9. A storage medium storing program code for a method for predicting ejection performance of a high-pressure fluid expansion ejection, characterized in that: The program code includes instructions for executing the high-pressure fluid expansion ejection performance prediction method according to any one of claims 1 to 5.

10. An electronic device comprising: memory and processor; The processor and the memory communicate with each other via a bus; The memory stores program instructions that can be executed by the processor, and is characterized in that the processor calls the program instructions to execute the high-pressure fluid expansion ejection performance prediction method according to any one of claims 1 to 5.

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