A method, device and system for predicting dynamic parameters of high-pressure gas storage tank

Abstract

The present invention provides a method, device and system for predicting the dynamic parameters of a high-pressure gas storage tank. The method of the present invention includes: obtaining a first temperature value and a first pressure value at a first moment, and determining the thermodynamic state parameters of the working fluid at the first moment; obtaining the volume of the gas storage tank, determining the total mass of the working fluid at the first moment, and determining the total mass of the working fluid at the second moment; determining the density of the working fluid at the second moment, and determining the specific thermodynamic energy of the working fluid at the second moment; determining the second temperature value and the second pressure value at the second moment, and when the second temperature value or the second pressure value reaches a set threshold, outputting the time series and the thermodynamic state parameters of the working fluid at the second moment. The thermal parameters at the next moment are predicted based on the temperature value and pressure value of the high-pressure gas storage tank at the initial moment, so as to realize the prediction of the dynamic parameters of the high-pressure gas storage tank, and then the operation plan can be adjusted in time according to the prediction results, so as to reduce hidden dangers and prolong the service life, and at the same time, it can provide a data basis for the sliding pressure operation plan of the compressed gas energy storage system.

Description

Technical Field

[0001] The present invention relates to the technical field of compressed gas energy storage, and in particular to a method, device and system for predicting dynamic parameters of a high-pressure gas storage tank. Background Art

[0002] The compressed gas energy storage system includes a high-pressure gas storage unit, among which the high-pressure gas storage tank is not restricted by geographical conditions and is widely used. Due to the inflow or outflow of working fluid, the internal temperature, pressure, density and other parameters of the high-pressure gas storage tank will change during the filling and discharge process. In order to ensure the safe operation of the gas storage tank, its dynamic parameters need to be predicted, and the operation plan should be adjusted in time according to the prediction results to reduce hidden dangers and prolong its life.

[0003] Currently, in the field of compressed gas energy storage, there are two common ways to calculate the thermal state of gas: 1) The working fluid is regarded as an ideal gas and the ideal gas state equation is used for calculation, but this method is only applicable to medium and low pressure states and has large errors; 2) The working fluid is regarded as an actual gas and the thermodynamic parameters are obtained by looking up a table or the actual gas state equation, but this method only considers the initial and final states of the working fluid and cannot explore the impact of the dynamic changes in the working fluid state on the energy storage system, resulting in insufficient in-depth research. Summary of the invention

[0004] The problem solved by the present invention is how to realize the prediction of dynamic parameters of a high-pressure gas storage tank to extend the service life of the gas storage tank.

[0005] To solve the above problems, the present invention provides a method for predicting dynamic parameters of a high-pressure gas storage tank, comprising: obtaining a first temperature value and a first pressure value at a first moment, and determining the thermodynamic state parameter of a working fluid at the first moment according to the first temperature value and the first pressure value; obtaining the volume of the gas storage tank, determining the total mass of the working fluid at the first moment according to the volume of the gas storage tank and the thermodynamic state parameter of the working fluid at the first moment, and determining the total mass of the working fluid at a second moment according to the total mass of the working fluid at the first moment; determining the density of the working fluid at the second moment according to the total mass of the working fluid at the second moment and the volume of the gas storage tank, and determining the specific thermodynamic energy of the working fluid at the second moment according to the total mass of the working fluid at the first moment, the total mass of the working fluid at the second moment, and the thermodynamic state parameter of the working fluid at the first moment; determining the second temperature value and the second pressure value at the second moment according to the specific thermodynamic energy of the working fluid at the second moment and the working fluid density at the second moment, and when the second temperature value or the second pressure value reaches a set threshold, outputting the time series and the thermodynamic state parameter of the working fluid at the second moment.

[0006] The method for predicting dynamic parameters of high-pressure gas storage tanks described in the present invention predicts the thermal parameters at the next moment according to the temperature value and pressure value of the high-pressure gas storage tank at the initial moment, thereby realizing the prediction of dynamic parameters of the high-pressure gas storage tank. Then, the operation plan can be adjusted in time according to the prediction results, thereby reducing hidden dangers and extending the service life. At the same time, it can provide a data basis for the sliding pressure operation plan of the compressed gas energy storage system.

[0007] Optionally, determining the thermodynamic state parameters of the working fluid at the first moment according to the first temperature value and the first pressure value includes: calling the CoolProp database to determine the working fluid specific enthalpy, working fluid specific thermodynamic energy and working fluid specific density at the first moment according to the first temperature value and the first pressure value.

[0008] The method for predicting dynamic parameters of a high-pressure gas storage tank described in the present invention determines the working fluid specific enthalpy, working fluid specific thermodynamic energy and working fluid specific density at the first moment by calling the CoolProp database, thereby realizing the prediction of dynamic parameters of a high-pressure gas storage tank.

[0009] Optionally, determining the total mass of the working fluid at the first moment according to the volume of the gas storage tank and the thermodynamic state parameter of the working fluid at the first moment includes: determining the total mass of the working fluid at the first moment according to the volume of the gas storage tank and the specific density of the working fluid at the first moment.

[0010] The method for predicting dynamic parameters of a high-pressure gas storage tank of the present invention determines the total mass of the working fluid at the first moment according to the volume of the gas storage tank and the specific density of the working fluid at the first moment, thereby realizing the prediction of dynamic parameters of the high-pressure gas storage tank.

[0011] Optionally, determining the total mass of the working fluid at the second moment based on the total mass of the working fluid at the first moment includes: determining the mass of the working fluid filled or released from the gas storage tank according to the mass flow rate of the working fluid, and determining the total mass of the working fluid at the second moment based on the mass of the working fluid filled or released from the gas storage tank and the total mass of the working fluid at the first moment.

[0012] The method for predicting dynamic parameters of a high-pressure gas storage tank described in the present invention determines the total mass of the working fluid at the second moment according to the mass of the working fluid charged into or discharged from the gas storage tank and the total mass of the working fluid at the first moment, thereby realizing the prediction of dynamic parameters of the high-pressure gas storage tank.

[0013] Optionally, determining the working fluid specific thermodynamic energy at the second moment according to the total mass of the working fluid at the first moment, the total mass of the working fluid at the second moment, and the thermodynamic state parameter of the working fluid at the first moment includes:

[0014] For the prediction of dynamic parameters of the charging process, the working fluid specific thermodynamic energy at the second moment is determined according to a first formula, wherein the first formula includes:

[0015]

[0016] Wherein, u2 represents the specific thermodynamic energy of the working fluid at the second moment during the charging process, u1 represents the specific thermodynamic energy of the working fluid at the first moment during the charging process, m2 represents the total mass of the working fluid at the second moment during the charging process, m1 represents the total mass of the working fluid at the first moment during the charging process, △m represents the mass of the working fluid charged into the gas storage tank, h0 represents the enthalpy value of the charging gas source, Q represents the heat exchange amount between the gas storage tank and the outside during the charging process, K represents the average heat exchange coefficient of the wall of the gas storage tank, F represents the heat exchange area, and △T represents the average heat exchange temperature difference between the working fluid inside the gas storage tank and the outside;

[0017] For the prediction of dynamic parameters of the deflation process, the working fluid specific thermodynamic energy at the second moment is determined according to a second formula, wherein the second formula includes:

[0018]

[0019] Wherein, u4 represents the specific thermodynamic energy of the working fluid at the second moment in the deflation process, u3 represents the specific thermodynamic energy of the working fluid at the first moment in the deflation process, m4 represents the total mass of the working fluid at the second moment in the deflation process, m3 represents the total mass of the working fluid at the first moment in the deflation process, h represents the deflation specific enthalpy, t4 represents the second moment in the deflation process, t3 represents the first moment in the deflation process, q out (t) represents the deflation mass flow rate at time t, W r dis Indicates the rated discharge power of the energy storage system, W i e (t) represents the output power of the i-th expander at time t, and M represents the total number of expander stages.

[0020] The method for predicting dynamic parameters of a high-pressure gas storage tank described in the present invention determines the specific thermodynamic energy of the working fluid at the second moment in the inflation process and the deflation process according to the first formula and the second formula, respectively, thereby realizing the prediction of dynamic parameters of the high-pressure gas storage tank.

[0021] Optionally, the method for predicting dynamic parameters of a high-pressure gas storage tank further includes: determining the mass of the working fluid charged into the gas storage tank according to a third formula, wherein the third formula includes:

[0022]

[0023] Among them, q in (t) represents the inflation mass flow rate at time t, t2 represents the second moment in the inflation process, t1 represents the first moment in the inflation process, △t represents the time interval from t1 to t2, Wr represents the rated charging power of the compressed energy storage system, w i(t) represents the power of the i-th compressor at time t, and N represents the total number of compressor stages.

[0024] The method for predicting dynamic parameters of a high-pressure gas storage tank described in the present invention determines the mass of the working fluid charged into the gas storage tank according to the third formula, thereby being able to predict the dynamic parameters of the high-pressure gas storage tank.

[0025] Optionally, the high-pressure gas storage tank dynamic parameter prediction method also includes: when the second temperature value and the second pressure value do not reach the set threshold value, using the second temperature value and the second pressure value as the temperature value and the pressure value at the initial moment, and continuously iterating and looping to determine the temperature value and the pressure value at each subsequent moment until the temperature value and the pressure value reach the set threshold value, stopping the iterative loop, and outputting the time series and the thermodynamic state parameters of the working fluid at the current moment.

[0026] The method for predicting dynamic parameters of a high-pressure gas storage tank described in the present invention obtains the value of the thermodynamic state parameter at each moment through an iterative cycle, stops the iterative cycle when a set threshold is reached, and outputs the time series and the thermodynamic state parameter of the working fluid at the current moment, thereby realizing the prediction of the dynamic parameters of the high-pressure gas storage tank.

[0027] The present invention also provides a high-pressure gas storage tank dynamic parameter prediction device, comprising:

[0028] a state parameter module, configured to obtain a first temperature value and a first pressure value at a first moment, and determine a thermodynamic state parameter of the working fluid at the first moment according to the first temperature value and the first pressure value;

[0029] A working fluid mass module, used to obtain the volume of the gas storage tank, determine the total mass of the working fluid at the first moment according to the volume of the gas storage tank and the thermodynamic state parameter of the working fluid at the first moment, and determine the total mass of the working fluid at the second moment according to the total mass of the working fluid at the first moment;

[0030] A working fluid specific thermodynamic energy module, used to determine the working fluid density at the second moment according to the total mass of the working fluid at the second moment and the volume of the gas storage tank, and to determine the working fluid specific thermodynamic energy at the second moment according to the total mass of the working fluid at the first moment, the total mass of the working fluid at the second moment and the thermodynamic state parameter of the working fluid at the first moment;

[0031] A parameter prediction module is used to determine the second temperature value and the second pressure value at the second moment according to the working fluid specific thermodynamic energy and the working fluid density at the second moment, and when the second temperature value or the second pressure value reaches a set threshold, output the time series and the working fluid thermodynamic state parameters at the second moment.

[0032] The advantages of the high-pressure gas storage tank dynamic parameter prediction device and the high-pressure gas storage tank dynamic parameter prediction method described above over the prior art are the same, and will not be described in detail here.

[0033] The present invention also provides a high-pressure gas storage tank dynamic parameter prediction system, comprising a computer-readable storage medium storing a computer program and a processor, wherein the computer program is read and executed by the processor to implement the high-pressure gas storage tank dynamic parameter prediction method as described above. The high-pressure gas storage tank dynamic parameter prediction system has the same advantages as the high-pressure gas storage tank dynamic parameter prediction method as compared with the prior art, which will not be described in detail here.

[0034] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is read and executed by a processor, the above high-pressure gas storage tank dynamic parameter prediction method is implemented. The advantages of the computer-readable storage medium and the above high-pressure gas storage tank dynamic parameter prediction method over the prior art are the same, and are not described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic flow chart of a method for predicting dynamic parameters of a high-pressure gas storage tank according to an embodiment of the present invention;

[0036] Figure 2 This is an example process of a method for predicting dynamic parameters of a high-pressure gas storage tank according to an embodiment of the present invention;

[0037] Figure 3 A schematic diagram of dynamic parameters of pressure during the inflation process according to an embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of dynamic temperature parameters of the inflation process according to an embodiment of the present invention;

[0039] Figure 5 A schematic diagram of dynamic parameters of thermodynamic energy of the inflation process according to an embodiment of the present invention;

[0040] Figure 6 It is a schematic diagram of dynamic parameters of specific enthalpy of the inflation process according to an embodiment of the present invention;

[0041] Figure 7 A schematic diagram of dynamic parameters of pressure during deflation process according to an embodiment of the present invention;

[0042] Figure 8 A schematic diagram of temperature dynamic parameters of a deflation process according to an embodiment of the present invention;

[0043] Fig. 9 It is a schematic diagram of dynamic parameters of enthalpy value of the degassing process according to an embodiment of the present invention;

[0044] Fig.10A schematic diagram of dynamic parameters of thermodynamic energy of the degassing process according to an embodiment of the present invention;

[0045] Fig.11 Schematic diagram of overall changes in temperature and pressure of a high-pressure gas storage tank according to an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In the field of compressed gas energy storage technology, there are the following problems:

[0047] (1) There are two common ways to characterize the thermodynamic state of gas working fluids in current compressed gas-related energy storage research: 1) The working fluid is regarded as an ideal gas and the ideal gas state equation is used for calculation. However, this method is only applicable to medium and low pressure gases and has poor adaptability and accuracy. 2) The working fluid is regarded as an actual gas and the thermodynamic state parameters are obtained by looking up a table or the actual gas state equation. However, this method only considers the initial and final states of the working fluid and cannot explore the impact of the dynamic changes in the working fluid's thermodynamic state on the overall energy storage system. Therefore, the research is not in-depth enough.

[0048] (2) Most studies on compressed gas energy storage only consider the working pressure range of high-pressure gas storage tanks when designing high-pressure gas storage tanks, and rarely involve the dynamic operation process of high-pressure gas storage tanks, resulting in a lack of basic data for the design scheme.

[0049] (3) During the operation of the compressed gas energy storage system, the charging and discharging of the high-pressure gas medium causes the thermodynamic parameters inside the high-pressure gas storage tank to change, affecting the operation of the entire system. However, current research usually only considers the initial and final states of the high-pressure gas storage tank, and rarely involves the dynamic process of the high-pressure gas storage tank. This leads to a large difference between the current operation plan and the actual project.

[0050] (4) During the operation of the compressed gas energy storage system, in order to improve the system energy efficiency, it is necessary to reduce the power consumption of the compressor unit and increase the work of the expansion unit. Sliding pressure operation is an effective way to improve energy efficiency. The formulation of the sliding pressure operation plan for the compressor unit and the expansion unit depends on the thermodynamic state of the high-pressure gas storage tank. However, current research rarely involves the dynamic process of the high-pressure gas storage tank, that is, there is a lack of data support for the dynamic changes of thermal parameters, which makes it impossible to make a specific sliding pressure operation plan, and there are obstacles to improving the system energy efficiency.

[0051] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0052] like Figure 1As shown, an embodiment of the present invention provides a method for predicting dynamic parameters of a high-pressure gas storage tank, including: obtaining a first temperature value and a first pressure value at a first moment, and determining a working fluid thermodynamic state parameter at the first moment according to the first temperature value and the first pressure value; obtaining a volume of the gas storage tank, determining a total mass of the working fluid at the first moment according to the volume of the gas storage tank and the working fluid thermodynamic state parameter at the first moment, and determining a total mass of the working fluid at a second moment according to the total mass of the working fluid at the first moment; determining a working fluid density at the second moment according to the total mass of the working fluid at the second moment and the volume of the gas storage tank, and determining a working fluid specific thermodynamic energy at the second moment according to the total mass of the working fluid at the first moment, the total mass of the working fluid at the second moment, and the working fluid thermodynamic state parameter at the first moment; determining a second temperature value and a second pressure value at the second moment according to the working fluid specific thermodynamic energy at the second moment and the working fluid density at the second moment, and when the second temperature value or the second pressure value reaches a set threshold, outputting a time series and a working fluid thermodynamic state parameter at the second moment.

[0053] Specifically, in this embodiment, combined with Figure 2 As shown, the dynamic parameter prediction method of the high-pressure gas storage tank includes:

[0054] Step 1: Use an instrument to measure the temperature and pressure values ​​at the initial moment, and input them as parameters into the CoolProp database to obtain other thermodynamic parameter values ​​corresponding to this state.

[0055] Step 2: Based on the actual volume of the tank, calculate the total mass of the working fluid at the initial moment.

[0056] Step 3: The charging / discharging mass flow parameter value is obtained by calculation, and the average value is calculated using the integration method to calculate the total mass change value of the working fluid within a specific time interval.

[0057] Step 4: Based on the above calculation results, the total mass and density of the working fluid corresponding to the final moment are obtained.

[0058] Step 5: Combine the characterization formula of the charging and discharging process in engineering thermodynamics to obtain the specific thermodynamic energy of the working fluid corresponding to the final moment.

[0059] Step 6: The parameters calculated in steps 4 and 5 can determine the thermodynamic state at the final moment, thereby obtaining the pressure, temperature and other values ​​corresponding to the final moment, and realizing the prediction of the thermodynamic state and parameter values ​​at the next moment.

[0060] Step 7: By predicting the temperature and pressure values ​​at the next moment, combined with the design parameters of the high-pressure gas storage tank, determine whether the design or operation threshold is reached. If the threshold is not reached, the data calculated at the final moment is assigned to the initial moment, and the iterative cycle is continued to obtain the thermodynamic state parameter values ​​at each moment, that is, to achieve dynamic parameter prediction; if the design threshold has been reached, stop the calculation and output the results. The obtained time series and its corresponding parameter values ​​are the dynamic parameter prediction results of the high-pressure gas storage tank. The above data can provide basic data for the operation plan of the compressed energy storage system after differential processing.

[0061] Take the dynamic model of the high-pressure gas tank filling process as an example (in order to improve the applicability of the model and method, all working fluids are regarded as ideal gases):

[0062] At the initial moment (first moment t1), the temperature T1 (first temperature value) and pressure P1 (first pressure value) of the working fluid in the high-pressure gas storage tank are measured by an instrument. The thermodynamic state parameters and the total mass of the working fluid at moment t1 can be calculated by formula (1):

[0063]

[0064] Wherein, h1 is the specific enthalpy of the working medium inside the high-pressure gas storage tank at time t1, in kJ / kg; T1 is the temperature of the working medium inside the high-pressure gas storage tank at time t1, in K; P1 is the pressure of the working medium inside the high-pressure gas storage tank at time t1, in MPa; u1 is the specific thermodynamic energy of the working medium inside the high-pressure gas storage tank at time t1, in kJ / kg; D1 is the specific density of the working medium inside the high-pressure gas storage tank at time t1, in kg / m 3 ; m1—total mass of working fluid inside the high-pressure gas storage tank at time t1, unit kg; V—volume of the high-pressure gas storage tank, unit m 3 .

[0065] In the △t time period, the mass of the working fluid charged into the high-pressure gas storage tank and the corresponding gas mass flow rate at each moment can be calculated by formula (2):

[0066]

[0067] Where, △m is the mass of the working fluid filled into the high-pressure gas storage tank, in kg; q in (t)—mass flow rate of the working fluid at time t, unit: kg / s; △t—time interval from t1 to t2, unit: s; Wr—rated charging power of the compressed energy storage system, unit: kW; w i (t)—The power of the i-th stage compressor at time t, in kW.

[0068] The total mass and density of the working fluid at time t2 are calculated by formula (3):

[0069]

[0070] Where m2 is the total mass of the working fluid at time t2, in kg; D2 is the density of the working fluid at time t2, in kg / m 3 ;

[0071] The specific thermodynamic energy of the working fluid at time t2 is calculated by formula (4):

[0072]

[0073] Where, u2—specific thermodynamic energy of the working fluid at time t2, unit kJ / kg; h0—gas source enthalpy, unit kJ / kg; Q—heat exchange between the high-pressure gas storage tank and the outside during the charging process, unit kJ; K—average heat transfer coefficient of the high-pressure gas storage tank wall, unit kJ / (m 2 ·K); F—heat exchange area, unit: m 2 ; △T—Average heat exchange temperature difference between the working fluid inside the high-pressure gas storage tank and the outside, unit K.

[0074] Other thermal parameters of the high-pressure gas storage tank at time t2 can be calculated by formula (5):

[0075]

[0076] Wherein, h2 is the specific enthalpy of the working fluid inside the high-pressure gas storage tank at time t2, u2 is the specific thermodynamic energy of the working fluid inside the high-pressure gas storage tank at time t2, and D2 is the specific density of the working fluid inside the high-pressure gas storage tank at time t2.

[0077] Formula (1) to Formula (5) are the dynamic models of the high-pressure gas tank filling process. Theoretically, the time interval △t from time t1 to time t2 can be infinitely subdivided, that is, the value can be an infinitesimal value close to 0, but for the convenience of research, △t can be taken as 1s; through logical deduction, the thermodynamic state and corresponding thermodynamic parameter values ​​corresponding to time t1 and time t2 can be obtained. After cyclic iteration and differential processing of the results, the prediction of the dynamic filling process of the high-pressure gas tank can be realized.

[0078] For the dynamic model of the high-pressure gas tank deflation process:

[0079] For the convenience of distinction, the initial time of the deflation process is set as t3, the final time is set as t4, and the interval is △t. At t3, the temperature value T3 and the pressure value P3 are measured by the instrument. The thermal parameters and the total mass of the working fluid at t3 are calculated by formula (6):

[0080]

[0081] In the formula, u3 is the specific thermodynamic energy of the working fluid inside the high-pressure gas storage tank at time t3, D3 is the working fluid density at time t3, m3 is the total mass of the working fluid inside the high-pressure gas storage tank at time t3, and D3 is the specific density of the working fluid inside the high-pressure gas storage tank at time t3. The specific thermodynamic energy and total mass of the working fluid at time t4 are calculated by formula (7):

[0082]

[0083] In the formula, h is the specific enthalpy of degassing, in kJ / kg; q is out (t)—the deflation mass flow rate at time t, in kg / s; W r dis —Rated discharge power of energy storage system, unit: kW; W i e (t)—output power of the i-th stage expander at time t, unit: kW; m3—total mass of the working fluid inside the high-pressure gas storage tank at time t3; m4—total mass of the working fluid inside the high-pressure gas storage tank at time t4.

[0084] The thermodynamic parameters at time t4 are calculated by formula (8):

[0085]

[0086] Wherein, D4 is the density of the working fluid at time t4, T4 is the temperature of the working fluid inside the high-pressure gas storage tank at time t4, P4 is the pressure of the working fluid inside the high-pressure gas storage tank at time t4, and u4 is the specific thermodynamic energy of the working fluid inside the high-pressure gas storage tank at time t4.

[0087] Equations (6) to (8) are the dynamic models of the high-pressure gas storage tank deflation process. Through logical deduction, the corresponding thermal parameter values ​​at time t3 and t4 can be obtained. After cyclic iteration and differential processing of the result sequence, the dynamic parameter prediction of the high-pressure gas storage tank deflation process can be realized.

[0088] The following is a verification example.

[0089] Python programming is used to implement the inflation process and deflation process respectively. For the convenience of research, it is assumed that the system inflation and deflation mass flow rates are both 5kg / s, and the design parameters of the high-pressure gas storage tank are shown in Table 1.

[0090] Table 1 Design parameters of high pressure gas storage tank

[0091]

[0092] Verification Example 1: Based on the parameters listed in Table 1, the inflation process with an initial state of 7MPa and 35°C, a gas source parameter of 10MPa and 40°C, and a time interval of 1s is studied; after the implementation of the method proposed in the present invention, it can be predicted that the inflation process from 7MPa to 10MPa takes a total of 5.39h, and the final temperature of the high-pressure gas storage tank is 55.16°C. The reason for the temperature rise is that the gas source is converted into thermodynamic energy during the process of charging the gas storage tank. The specific process is as follows Figure 3-Figure 6 As shown, the calculation results can provide a data basis for formulating sliding pressure operation plans for compressed gas energy storage systems and compressor units.

[0093] Verification Example 2: Based on the parameters listed in Table 1, the deflation process with an initial state of 10MPa, 55.16℃, a deflation mass flow rate of 5kg / s, and a time interval of 1s is studied; after the implementation of the method proposed in the present invention, it can be predicted that the deflation from 10MPa to 7MPa takes a total of 2.52h, the final temperature of the high-pressure gas storage tank is 30.76℃, and the final pressure is 7MPa. The reason for the decrease in the internal working fluid temperature is that the thermodynamic energy is converted into driving work. The calculation results can provide a data basis for the compressed gas energy storage system and the expansion unit to formulate a sliding pressure operation plan. The specific process is as follows Figure 7-Figure 10 In addition, Fig.11 Shows the overall changes in temperature and pressure of the high-pressure gas storage tank.

[0094] In this embodiment, the thermal parameters at the next moment are predicted based on the temperature and pressure values ​​of the high-pressure gas storage tank at the initial moment, so as to realize the prediction of the dynamic parameters of the high-pressure gas storage tank. Then, the operation plan can be adjusted in time according to the prediction results to reduce hidden dangers and extend the service life. At the same time, it can provide a data basis for the sliding pressure operation plan of the compressed gas energy storage system.

[0095] Optionally, determining the thermodynamic state parameters of the working fluid at the first moment according to the first temperature value and the first pressure value includes: calling the CoolProp database to determine the working fluid specific enthalpy, working fluid specific thermodynamic energy and working fluid specific density at the first moment according to the first temperature value and the first pressure value.

[0096] Specifically, in this embodiment, an instrument is used to measure the temperature and pressure values ​​at the initial moment, and they are input into the CoolProp database as parameters to obtain other thermodynamic parameter values ​​corresponding to the state, such as working fluid specific enthalpy, working fluid specific thermodynamic energy and working fluid specific density.

[0097] Among them, coolprop is an open source physical property calculation library developed based on C++. In layman's terms, it is a calculation library used to calculate physical property parameters such as density, saturation temperature, pressure and viscosity of water, steam and air.

[0098] In this embodiment, the CoolProp database is called to determine the working fluid specific enthalpy, working fluid specific thermodynamic energy and working fluid specific density at the first moment, thereby enabling the prediction of dynamic parameters of the high-pressure gas storage tank.

[0099] Optionally, determining the total mass of the working fluid at the first moment according to the volume of the gas storage tank and the thermodynamic state parameter of the working fluid at the first moment includes: determining the total mass of the working fluid at the first moment according to the volume of the gas storage tank and the specific density of the working fluid at the first moment.

[0100] Specifically, in this embodiment, the thermodynamic state parameters of the working fluid include the working fluid specific density. For example, during the charging process, the total mass m1 of the working fluid inside the high-pressure gas storage tank at time t1 is equal to the volume V of the gas storage tank multiplied by the working fluid specific density D1 inside the high-pressure gas storage tank at time t1, thereby enabling the prediction of the dynamic parameters of the high-pressure gas storage tank.

[0101] In this embodiment, the total mass of the working fluid at the first moment is determined according to the volume of the gas storage tank and the specific density of the working fluid at the first moment, thereby realizing the prediction of the dynamic parameters of the high-pressure gas storage tank.

[0102] Optionally, determining the total mass of the working fluid at the second moment based on the total mass of the working fluid at the first moment includes: determining the mass of the working fluid filled or released from the gas storage tank according to the mass flow rate of the working fluid, and determining the total mass of the working fluid at the second moment based on the mass of the working fluid filled or released from the gas storage tank and the total mass of the working fluid at the first moment.

[0103] Specifically, in this embodiment, according to formulas (2) and (3), the total mass m2 of the working fluid at time t2 is equal to the total mass m1 of the working fluid at time t1 plus the mass △m of the working fluid charged into the high-pressure gas storage tank; according to formula (7), the total mass m4 of the working fluid at time t4 is equal to the total mass m3 of the working fluid at time t3 minus the mass of the working fluid released.

[0104] In this embodiment, the total mass of the working fluid at the second moment is determined according to the mass of the working fluid charged into or discharged from the gas storage tank and the total mass of the working fluid at the first moment, thereby enabling prediction of dynamic parameters of the high-pressure gas storage tank.

[0105] Optionally, determining the working fluid specific thermodynamic energy at the second moment according to the total mass of the working fluid at the first moment, the total mass of the working fluid at the second moment, and the thermodynamic state parameter of the working fluid at the first moment includes:

[0106] For the prediction of dynamic parameters of the charging process, the working fluid specific thermodynamic energy at the second moment is determined according to a first formula, wherein the first formula includes:

[0107]

[0108] Wherein, u2 represents the specific thermodynamic energy of the working fluid at the second moment during the charging process, u1 represents the specific thermodynamic energy of the working fluid at the first moment during the charging process, m2 represents the total mass of the working fluid at the second moment during the charging process, m1 represents the total mass of the working fluid at the first moment during the charging process, △m represents the mass of the working fluid charged into the gas storage tank, h0 represents the enthalpy value of the charging gas source, Q represents the heat exchange amount between the gas storage tank and the outside during the charging process, K represents the average heat exchange coefficient of the wall of the gas storage tank, F represents the heat exchange area, and △T represents the average heat exchange temperature difference between the working fluid inside the gas storage tank and the outside;

[0109] For the prediction of dynamic parameters of the deflation process, the working fluid specific thermodynamic energy at the second moment is determined according to a second formula, wherein the second formula includes:

[0110]

[0111] Wherein, u4 represents the specific thermodynamic energy of the working fluid at the second moment in the deflation process, u3 represents the specific thermodynamic energy of the working fluid at the first moment in the deflation process, m4 represents the total mass of the working fluid at the second moment in the deflation process, m3 represents the total mass of the working fluid at the first moment in the deflation process, h represents the deflation specific enthalpy, t4 represents the second moment in the deflation process, t3 represents the first moment in the deflation process, q out (t) represents the deflation mass flow rate at time t, W r dis Indicates the rated discharge power of the energy storage system, W i e (t) represents the output power of the i-th expander at time t, and M represents the total number of expander stages.

[0112] Specifically, in this embodiment, for the prediction of dynamic parameters of the inflation process, the specific thermodynamic energy of the working fluid at the second moment is determined according to the first formula, i.e., formula (4); for the prediction of dynamic parameters of the deflation process, the specific thermodynamic energy of the working fluid at the second moment is determined according to the second formula, i.e., formula (7).

[0113] In this embodiment, the specific thermodynamic energy of the working fluid at the second moment in the charging process and the deflation process is determined according to the first formula and the second formula, respectively, so as to realize the prediction of the dynamic parameters of the high-pressure gas storage tank.

[0114] Optionally, the method for predicting dynamic parameters of a high-pressure gas storage tank further includes: determining the mass of the working fluid charged into the gas storage tank according to a third formula, wherein the third formula includes:

[0115]

[0116] Among them, q in(t) represents the inflation mass flow rate at time t, t2 represents the second moment in the inflation process, t1 represents the first moment in the inflation process, △t represents the time interval from t1 to t2, Wr represents the rated charging power of the compressed energy storage system, w i (t) represents the power of the i-th compressor at time t, and N represents the total number of compressor stages.

[0117] Specifically, in this embodiment, the mass of the working fluid charged into the gas tank is determined according to the third formula, i.e., formula (2). The mass of the working fluid charged into the gas tank depends on the integral value of the charging mass flow rate from time t1 to time t2, and the charging mass flow rate is related to the rated charging power of the compressed energy storage system and the compressor power.

[0118] In this embodiment, the mass of the working fluid charged into the gas storage tank is determined according to the third formula, thereby enabling the prediction of the dynamic parameters of the high-pressure gas storage tank.

[0119] Optionally, the high-pressure gas storage tank dynamic parameter prediction method also includes: when the second temperature value and the second pressure value do not reach the set threshold value, using the second temperature value and the second pressure value as the temperature value and the pressure value at the initial moment, and continuously iterating and looping to determine the temperature value and the pressure value at each subsequent moment until the temperature value and the pressure value reach the set threshold value, stopping the iterative loop, and outputting the time series and the thermodynamic state parameters of the working fluid at the current moment.

[0120] Specifically, in this embodiment, by predicting the temperature and pressure values ​​at the next moment and combining the design parameters of the high-pressure gas storage tank, it is determined whether the design or operation threshold is reached. If the threshold is not reached, the data calculated at the final moment is assigned to the initial moment, and the iterative cycle is continued to obtain the thermodynamic state parameter values ​​at each moment, that is, dynamic parameter prediction is achieved.

[0121] In this embodiment, the thermodynamic state parameter value at each moment is obtained through an iterative loop, and the iterative loop is stopped when the set threshold is reached, and the time series and the thermodynamic state parameter of the working fluid at the current moment are output, thereby realizing the dynamic parameter prediction of the high-pressure gas storage tank.

[0122] Another embodiment of the present invention provides a high-pressure gas storage tank dynamic parameter prediction device, comprising:

[0123] a state parameter module, configured to obtain a first temperature value and a first pressure value at a first moment, and determine a thermodynamic state parameter of the working fluid at the first moment according to the first temperature value and the first pressure value;

[0124] A working fluid mass module, used to obtain the volume of the gas storage tank, determine the total mass of the working fluid at the first moment according to the volume of the gas storage tank and the thermodynamic state parameter of the working fluid at the first moment, and determine the total mass of the working fluid at the second moment according to the total mass of the working fluid at the first moment;

[0125] A working fluid specific thermodynamic energy module, used to determine the working fluid density at the second moment according to the total mass of the working fluid at the second moment and the volume of the gas storage tank, and to determine the working fluid specific thermodynamic energy at the second moment according to the total mass of the working fluid at the first moment, the total mass of the working fluid at the second moment and the thermodynamic state parameter of the working fluid at the first moment;

[0126] A parameter prediction module is used to determine the second temperature value and the second pressure value at the second moment according to the working fluid specific thermodynamic energy and the working fluid density at the second moment, and when the second temperature value or the second pressure value reaches a set threshold, output the time series and the working fluid thermodynamic state parameters at the second moment.

[0127] Another embodiment of the present invention provides a high-pressure gas storage tank dynamic parameter prediction system, including a computer-readable storage medium storing a computer program and a processor, and when the computer program is read and executed by the processor, the high-pressure gas storage tank dynamic parameter prediction method as described above is implemented.

[0128] Another embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is read and executed by a processor, the above method for predicting dynamic parameters of a high-pressure gas storage tank is implemented.

[0129] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A method for predicting dynamic parameters of a high-pressure gas storage tank, characterized in that: include: Acquire a first temperature value and a first pressure value at a first moment, and determine a thermodynamic state parameter of the working fluid at the first moment according to the first temperature value and the first pressure value; Acquire the volume of the gas storage tank, determine the total mass of the working fluid at the first moment according to the volume of the gas storage tank and the thermodynamic state parameter of the working fluid at the first moment, and determine the total mass of the working fluid at the second moment according to the total mass of the working fluid at the first moment; Determine the working fluid density at the second moment according to the total mass of the working fluid at the second moment and the volume of the gas storage tank, and determine the working fluid specific thermodynamic energy at the second moment according to the total mass of the working fluid at the first moment, the total mass of the working fluid at the second moment, and the thermodynamic state parameter of the working fluid at the first moment; The second temperature value and the second pressure value at the second moment are determined according to the working fluid specific thermodynamic energy and the working fluid density at the second moment, and when the second temperature value or the second pressure value reaches a set threshold, the time series and the working fluid thermodynamic state parameters at the second moment are output.

2. The method for predicting dynamic parameters of a high-pressure gas storage tank according to claim 1, characterized in that: Determining the thermodynamic state parameters of the working fluid at the first moment according to the first temperature value and the first pressure value includes: calling the CoolProp database, and determining the working fluid specific enthalpy, working fluid specific thermodynamic energy and working fluid specific density at the first moment according to the first temperature value and the first pressure value.

3. The method for predicting dynamic parameters of a high-pressure gas storage tank according to claim 2, characterized in that: Determining the total mass of the working fluid at the first moment according to the volume of the gas storage tank and the thermodynamic state parameter of the working fluid at the first moment includes: determining the total mass of the working fluid at the first moment according to the volume of the gas storage tank and the specific density of the working fluid at the first moment.

4. The method for predicting dynamic parameters of a high-pressure gas storage tank according to claim 1, characterized in that: Determining the total mass of the working fluid at the second moment according to the total mass of the working fluid at the first moment includes: determining the mass of the working fluid charged into or discharged from the gas storage tank according to the mass flow rate of the working fluid, and determining the total mass of the working fluid at the second moment according to the mass of the working fluid charged into or discharged from the gas storage tank and the total mass of the working fluid at the first moment.

5. The method for predicting dynamic parameters of a high-pressure gas storage tank according to claim 4, characterized in that: Determining the specific thermodynamic energy of the working fluid at the second moment according to the total mass of the working fluid at the first moment, the total mass of the working fluid at the second moment, and the thermodynamic state parameter of the working fluid at the first moment includes: For the prediction of dynamic parameters of the charging process, the working fluid specific thermodynamic energy at the second moment is determined according to a first formula, wherein the first formula includes: Wherein, u2 represents the specific thermodynamic energy of the working fluid at the second moment during the charging process, u1 represents the specific thermodynamic energy of the working fluid at the first moment during the charging process, m2 represents the total mass of the working fluid at the second moment during the charging process, m1 represents the total mass of the working fluid at the first moment during the charging process, △m represents the mass of the working fluid charged into the gas storage tank, h0 represents the enthalpy value of the charging gas source, Q represents the heat exchange amount between the gas storage tank and the outside during the charging process, K represents the average heat exchange coefficient of the wall of the gas storage tank, F represents the heat exchange area, and △T represents the average heat exchange temperature difference between the working fluid inside the gas storage tank and the outside; For the prediction of dynamic parameters of the deflation process, the working fluid specific thermodynamic energy at the second moment is determined according to a second formula, wherein the second formula includes: Wherein, u4 represents the specific thermodynamic energy of the working fluid at the second moment in the deflation process, u3 represents the specific thermodynamic energy of the working fluid at the first moment in the deflation process, m4 represents the total mass of the working fluid at the second moment in the deflation process, m3 represents the total mass of the working fluid at the first moment in the deflation process, h represents the deflation specific enthalpy, t4 represents the second moment in the deflation process, t3 represents the first moment in the deflation process, q out (t) represents the deflation mass flow rate at time t, W r dis Indicates the rated discharge power of the energy storage system, W i e (t) represents the output power of the i-th expander at time t, and M represents the total number of expander stages.

6. The method for predicting dynamic parameters of a high-pressure gas storage tank according to claim 5, characterized in that: Also includes: The mass of the working fluid charged into the gas storage tank is determined according to a third formula, wherein the third formula includes: Among them, q in (t) represents the inflation mass flow rate at time t, t2 represents the second moment in the inflation process, t1 represents the first moment in the inflation process, △t represents the time interval from t1 to t2, Wr represents the rated charging power of the compressed energy storage system, w i (t) represents the power of the i-th compressor at time t, and N represents the total number of compressor stages.

7. The method for predicting dynamic parameters of a high-pressure gas storage tank according to claim 1, characterized in that: Also includes: When the second temperature value and the second pressure value do not reach the set threshold value, the second temperature value and the second pressure value are used as the temperature value and the pressure value at the initial moment, and the iterative cycle is continuously performed to determine the temperature value and the pressure value at each subsequent moment until the temperature value and the pressure value reach the set threshold value, and the iterative cycle is stopped, and the time series and the thermodynamic state parameters of the working fluid at the current moment are output.

8. A high-pressure gas storage tank dynamic parameter prediction device, characterized in that: include: a state parameter module, configured to obtain a first temperature value and a first pressure value at a first moment, and determine a thermodynamic state parameter of the working fluid at the first moment according to the first temperature value and the first pressure value; A working fluid mass module, used to obtain the volume of the gas storage tank, determine the total mass of the working fluid at the first moment according to the volume of the gas storage tank and the thermodynamic state parameter of the working fluid at the first moment, and determine the total mass of the working fluid at the second moment according to the total mass of the working fluid at the first moment; A working fluid specific thermodynamic energy module, used to determine the working fluid density at the second moment according to the total mass of the working fluid at the second moment and the volume of the gas storage tank, and to determine the working fluid specific thermodynamic energy at the second moment according to the total mass of the working fluid at the first moment, the total mass of the working fluid at the second moment and the thermodynamic state parameter of the working fluid at the first moment; A parameter prediction module is used to determine the second temperature value and the second pressure value at the second moment according to the working fluid specific thermodynamic energy and the working fluid density at the second moment, and when the second temperature value or the second pressure value reaches a set threshold, output the time series and the working fluid thermodynamic state parameters at the second moment.

9. A high-pressure gas storage tank dynamic parameter prediction system, characterized in that: It comprises a computer-readable storage medium storing a computer program and a processor, wherein when the computer program is read and executed by the processor, the method for predicting dynamic parameters of a high-pressure gas storage tank as claimed in any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is read and executed by a processor, the method for predicting dynamic parameters of a high-pressure gas storage tank according to any one of claims 1 to 7 is implemented.

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