Gasoline Reid vapor pressure prediction method, device and equipment and storage medium

Abstract

The invention discloses a gasoline Reid steam pressure prediction method and device. The method comprises the following steps: according to molecular component data of a to-be-tested gasoline sample, judging whether the to-be-tested gasoline sample can reach a flash evaporation equilibrium state under a flash evaporation model calculation condition or not, if not, adjusting operation pressure in the flash evaporation model calculation condition, and continuing to judge whether the to-be-tested gasoline sample can reach the flash evaporation equilibrium state or not; if yes, determining a second gasification fraction of the to-be-tested gasoline sample under the flash evaporation model calculation condition; judging whether a difference value between the second gasification fraction and the first gasification fraction is smaller than preset precision or not, if not, adjusting the first gasification fraction, and continuing to judge whether the gasoline sample to be tested can reach a flash evaporation equilibrium state or not; and if the precision is less than the preset precision, taking the operation pressure in the current flash evaporation model calculation condition as the Reid steam pressure of the gasoline sample to be tested. The gasoline Reid steam pressure can be quickly and accurately predicted, and the method has universality.

Description

Technical Field

[0001] This invention relates to the field of crude oil processing technology, and in particular to a method, apparatus, equipment, and storage medium for predicting the red vapor pressure of gasoline. Background Technology

[0002] Reid Vapor Pressure (RVP) is an important indicator of gasoline's evaporative performance, reflecting its vapor lock tendency under starting, heating, high-temperature, or high-latitude conditions. When the Reid Vapor Pressure is too low, it indicates that the gasoline is difficult to vaporize, leading to difficulty starting the car, uneven mixing of fuel and air, incomplete combustion, and increased emissions of pollutants such as CO2 and hydrocarbons. Conversely, when the Reid Vapor Pressure is too high, it indicates excessive evaporative performance, causing the gasoline to easily vaporize and resulting in increased evaporative emissions, specifically increased VOCs (volatile organic compounds). This can also create vapor lock in the fuel lines, potentially interrupting fuel supply.

[0003] In existing technologies, the Reid vapor pressure (RVP) of gasoline samples can be predicted using a correlation method. This method correlates the infrared spectra, gas chromatography, distillation curves, and RVP of various gasoline samples to obtain a prediction model. The RVP of the gasoline sample to be tested can then be obtained based on this model. However, this method requires an existing database storing the infrared spectra, gas chromatography, distillation curves, and RVP of various gasoline samples. Summary of the Invention

[0004] Predictive models using existing technologies can predict the Reid vapor pressure of gasoline samples stored in a database. However, for gasoline samples not stored in the database, the prediction model parameters need to be retrained. Therefore, the prediction model obtained using this method lacks universality and has high maintenance costs. Thus, developing a universally applicable prediction method to accurately and quickly predict the Reid vapor pressure of gasoline samples is an urgent technical problem to be solved.

[0005] In view of the above problems, the present invention is proposed to provide a method and apparatus for predicting gasoline Red vapor pressure that overcomes or at least partially solves the above problems.

[0006] In a first aspect, embodiments of the present invention provide a method for predicting gasoline Reid vapor pressure, comprising:

[0007] Based on the molecular composition data of the gasoline sample to be tested, it is determined whether the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions. The flash model calculation conditions include: operating temperature, first vaporization fraction and operating pressure.

[0008] If flash evaporation cannot reach equilibrium, the operating pressure in the flash evaporation model calculation conditions is adjusted using the preset pressure adjustment rules, and the step of determining whether the gasoline sample to be tested can reach flash evaporation equilibrium under the flash evaporation model calculation conditions is continued; if equilibrium can be reached, the second vaporization fraction of the gasoline sample to be tested under the flash evaporation model calculation conditions is determined.

[0009] Determine whether the difference between the second vaporization fraction and the first vaporization fraction is less than the preset accuracy. If it is not less than the preset accuracy, adjust the first vaporization fraction in the flash model calculation conditions according to the preset vaporization fraction adjustment rules, and continue to execute the step of determining whether the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions. If it is less than the preset accuracy, use the operating pressure in the current flash model calculation conditions as the Reid vapor pressure of the gasoline sample to be tested.

[0010] In some optional embodiments, under flash model calculation conditions, based on the molecular composition data of the gasoline sample to be tested, it is determined whether the gasoline sample to be tested can reach flash equilibrium under flash model calculation conditions, including:

[0011] Under the flash model calculation conditions, based on the molecular composition data of the gasoline sample to be tested, the gas phase content and liquid phase content of all components of the gasoline sample to be tested under the flash state are obtained;

[0012] Based on the gas phase and liquid phase contents of all components of the gasoline sample under flash evaporation, it is determined whether the gasoline sample can reach flash equilibrium under the conditions calculated by the flash evaporation model.

[0013] In some optional embodiments, under flash model calculation conditions, based on the molecular composition data of the gasoline sample to be tested, the gas phase content and liquid phase content of all components of the gasoline sample under flash conditions are obtained, including:

[0014] For each component of the gasoline sample to be tested, perform the following operations:

[0015] Based on the operating temperature, operating pressure, and molecular composition data of the components, the gas phase fugacity coefficient and liquid phase fugacity coefficient of the components are determined under the flash evaporation model calculation conditions.

[0016] The phase equilibrium constants of the components under the calculation conditions of the flash evaporation model are determined based on the gas phase fugacity coefficient and the liquid phase fugacity coefficient.

[0017] Based on the phase equilibrium constant, the first vaporization fraction, and the molecular composition data of the components, the gas phase content and liquid phase content of the components under flash evaporation conditions are calculated.

[0018] In some optional embodiments, based on the gas phase and liquid phase contents of all components of the gasoline sample under flash evaporation, it is determined whether the gasoline sample can reach flash equilibrium under the conditions calculated by the flash evaporation model, including:

[0019] Determine the difference between the gas phase content and liquid phase content of each component in the gasoline sample to be tested under flash evaporation conditions;

[0020] If the sum of all differences is less than the preset equilibrium threshold, it is determined that the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions;

[0021] If the sum of all differences is not less than the preset equilibrium threshold, it is determined that the gasoline sample to be tested cannot reach the flash equilibrium state under the flash model calculation conditions.

[0022] In some optional embodiments, determining the second vaporization fraction of the gasoline sample under flash model calculation conditions includes:

[0023] Using the SRK equation of state, the density of the separated mixed gas phase of the gasoline sample under flash equilibrium was calculated when the sample reached flash equilibrium under the flash model calculation conditions.

[0024] Using the improved Rackett equation, the density of the mixed liquid phase separated when the gasoline sample under the flash model reaches flash equilibrium was calculated.

[0025] The second gasification fraction is obtained based on the density of the mixed gas phase and the density of the mixed liquid phase.

[0026] In some optional embodiments, the density of the separated gas phase of the gasoline sample under flash equilibrium is calculated using the SRK equation of state, including:

[0027] The molar volume of the mixed gas phase of the gasoline sample to be tested was obtained using the SRK equation of state.

[0028] Based on the molar volume of the mixed gas phase, the molecular weight and mass content of the molecules in the mixed gas phase of the gasoline sample to be tested, the density of the mixed gas phase separated when the gasoline sample to be tested reaches the flash equilibrium state under the flash model calculation conditions is obtained.

[0029] In some optional embodiments, the density of the separated liquid phase of the gasoline sample under flash equilibrium is calculated using the modified Rackett equation, including:

[0030] The molar volume of the mixed liquid phase of the gasoline sample to be tested was obtained using the improved Rackett equation.

[0031] Based on the molar volume of the mixed liquid phase, the mass content of the components in the mixed liquid phase of the gasoline sample to be tested, and the density of the components, the density of the mixed liquid phase separated when the gasoline sample to be tested reaches the flash equilibrium state under the flash model calculation conditions is obtained.

[0032] In some optional embodiments, the operating pressure in the flash model calculation conditions is adjusted using preset pressure adjustment rules, including:

[0033] The operating pressure in the calculation conditions of the flash evaporation model was adjusted using an adjustment algorithm.

[0034] or;

[0035] Determine the pressure adjustment amount according to the preset pressure adjustment ratio, and adjust the operating pressure in the flash evaporation model calculation conditions based on the pressure adjustment amount.

[0036] In some optional embodiments, the first gasification fraction in the flash model calculation conditions is adjusted according to a preset gasification fraction adjustment rule, including:

[0037] Adjust the value of the first gasification fraction based on the value of the second gasification fraction;

[0038] or;

[0039] According to the preset differentiation rate adjustment ratio, determine the differentiation rate adjustment amount, and adjust the first gasification fraction in the flash evaporation model calculation conditions based on the differentiation rate adjustment amount.

[0040] Secondly, embodiments of the present invention provide a gasoline red vapor pressure prediction device, comprising:

[0041] The first judgment module is used to determine whether the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions based on the molecular composition data of the gasoline sample to be tested. The flash model calculation conditions include: operating temperature, first vaporization fraction and operating pressure.

[0042] The first adjustment module is used to adjust the operating pressure in the flash model calculation conditions using a preset pressure adjustment rule when the first judgment module determines that the gasoline sample to be tested cannot reach the flash equilibrium state. It then notifies the first judgment module to continue executing the step of judging whether the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions.

[0043] The vaporization fraction determination module is used to determine the second vaporization fraction of the gasoline sample under the flash model calculation conditions when the first judgment module determines that the gasoline sample to be tested can reach the equilibrium state.

[0044] The second judgment module is used to determine whether the difference between the second gasification fraction and the first gasification fraction is less than the preset precision.

[0045] The second adjustment module is used to adjust the first vaporization fraction in the flash model calculation conditions according to the preset vaporization fraction adjustment rules when the second judgment module determines that the difference between the second vaporization fraction and the first vaporization fraction is not less than the preset accuracy, and to notify the first judgment module to continue to execute the step of judging whether the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions.

[0046] The pressure determination module is used to take the operating pressure in the current flash model calculation conditions as the Reid vapor pressure of the gasoline sample to be tested when the second judgment module determines that the difference between the second vaporization fraction and the first vaporization fraction is less than the preset accuracy.

[0047] This invention provides a computer storage medium storing computer-executable instructions, which, when executed by a processor, implement the aforementioned gasoline red vapor pressure prediction method.

[0048] This invention provides a terminal device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the above-described gasoline Reid vapor pressure prediction method.

[0049] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0050] The gasoline Reid vapor pressure prediction method provided in this embodiment determines whether the gasoline sample can reach flash equilibrium under flash model calculation conditions based on the molecular composition data of the gasoline sample to be tested. The flash model calculation conditions include: operating temperature, first vaporization fraction, and operating pressure. If flash equilibrium cannot be reached, the operating pressure in the flash model calculation conditions is adjusted using a preset pressure adjustment rule, and the step of determining whether the gasoline sample can reach flash equilibrium under the flash model calculation conditions is continued. If equilibrium can be reached, the second vaporization fraction of the gasoline sample under the flash model calculation conditions is determined. Compared with existing prediction model methods, this method does not require a large amount of gasoline sample data for modeling and prediction. Moreover, this method is not limited to the vapor pressure of gasoline samples already in the prediction database. It can be used to predict any gasoline sample to be predicted, thus improving prediction efficiency and having universal applicability.

[0051] If the difference between the second vaporization fraction and the first vaporization fraction is not less than the preset accuracy, the first vaporization fraction in the flash model calculation conditions is adjusted according to the preset vaporization fraction adjustment rules, and the step of judging whether the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions continues. By iteratively adjusting multiple times, the error between vaporization fractions is reduced, and the prediction accuracy is improved. If the difference between the second vaporization fraction and the first vaporization fraction is less than the preset accuracy, the operating pressure in the current flash model calculation conditions is used as the Reid vapor pressure of the gasoline sample to be tested. This method can further calculate the required Reid vapor pressure based on the molecular composition data of the gasoline sample to be tested. It is universally applicable to various gasoline samples to be tested, and can accurately and quickly obtain the Reid vapor pressure of the gasoline sample to be tested, providing strong technical support for actual industrial production.

[0052] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0053] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0054] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0055] Figure 1 This is a flowchart of the gasoline Reid vapor pressure prediction method in an embodiment of the present invention;

[0056] Figure 2 This is a flowchart illustrating the process of determining the gas phase and liquid phase contents of components in a gasoline sample to be tested, as described in this embodiment of the invention.

[0057] Figure 3 This is a schematic diagram of the gasoline red vapor pressure prediction device in an embodiment of the present invention. Detailed Implementation

[0058] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0059] To address the problem that existing prediction models are complex and not universally applicable, this invention provides a method, apparatus, device, and storage medium for predicting gasoline Red vapor pressure.

[0060] This invention provides a method for predicting gasoline Reid vapor pressure, the process of which is as follows: Figure 1 As shown, it includes the following steps:

[0061] Step S101: Based on the molecular composition data of the gasoline sample to be tested, determine whether the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions; if yes, proceed to step S102; if no, proceed to step S103; the flash model calculation conditions include: operating temperature, first vaporization fraction and operating pressure.

[0062] Step S102: Determine the second vaporization fraction of the gasoline sample to be tested under the flash model calculation conditions.

[0063] Step S103: Adjust the operating pressure in the flash model calculation conditions using the preset pressure adjustment rules, and continue to execute step S101.

[0064] Step S104: Determine whether the difference between the second gasification fraction and the first gasification fraction is less than the preset precision; if yes, proceed to step S105; if no, proceed to step S106.

[0065] Step S105: Use the operating pressure in the current flash model calculation conditions as the Reid vapor pressure of the gasoline sample to be tested.

[0066] Step S106: Adjust the first gasification fraction in the flash model calculation conditions according to the preset gasification fraction adjustment rules, and continue to execute step S101.

[0067] In this embodiment of the invention, the process of measuring the Reid vapor pressure of gasoline is treated as an equilibrium flash vaporization process for calculation. Based on the gasoline molecular composition data obtained from actual detection, the Reid vapor pressure of the gasoline sample to be tested is calculated iteratively. The flash vaporization model calculation conditions are established based on the above-mentioned equilibrium flash vaporization process, used to obtain the vaporization fraction when the flash vaporization process reaches equilibrium under these calculation conditions. The flash vaporization model calculation conditions include: operating temperature, operating pressure, and a first vaporization fraction; wherein the operating temperature is 37.8℃, determined based on the Reid vapor pressure test experiment of gasoline. Under the initial calculation conditions, the flash vaporization model calculation conditions include: operating temperature 37.8℃, a preset first vaporization fraction, and a preset operating pressure; in each subsequent iterative calculation, the flash vaporization model calculation conditions include: operating temperature 37.8℃, the first vaporization fraction adjusted according to the previous calculation result, and the operating pressure adjusted according to the previous calculation result. Through multiple iterative calculations, the first vaporization fraction and operating pressure are adjusted, resulting in a smaller final prediction error and a more accurate prediction result.

[0068] The first vaporization fraction is the estimated vaporization fraction of the gasoline sample under test when it reaches flash equilibrium under the operating pressure and temperature specified in the flash model calculation conditions. The initial value of the first vaporization fraction is a preset value, which is adjusted according to the preset vaporization fraction adjustment rules in each subsequent iteration calculation.

[0069] The second vaporization fraction is the vaporization fraction calculated when the gasoline sample to be tested reaches the flash equilibrium state under the operating pressure, operating temperature and the first vaporization fraction as defined by the flash model calculation conditions.

[0070] When the difference between the first vaporization fraction and the second vaporization fraction is small, approximately equal, or completely equal, it can be considered that the gasoline sample under test can reach a flash vaporization equilibrium state under the operating pressure and operating temperature specified by the flash vaporization model calculation conditions. Therefore, the current value of the operating pressure at this point is taken as the final Reid vapor pressure value. Continuously adjusting the first vaporization fraction through preset pressure adjustment rules to minimize the error between the first and second vaporization fractions will result in more accurate measurement results.

[0071] In the specific implementation process, it can be determined whether the difference between the second vaporization fraction and the first vaporization fraction is less than the preset accuracy, for example, 0.0001. If the difference is less than the preset accuracy, it can be considered that the flash vaporization process can reach an equilibrium state under the current operating pressure and operating temperature, and the current operating pressure value can be used as the Reid vapor pressure value of the gasoline sample to be tested.

[0072] Optionally, in step S101 above, under the flash model calculation conditions, determining whether the gasoline sample to be tested can reach flash equilibrium under the flash model calculation conditions based on the molecular composition data of the gasoline sample to be tested includes:

[0073] Under the flash model calculation conditions, based on the molecular composition data of the gasoline sample to be tested, the gas phase content and liquid phase content of all components of the gasoline sample to be tested under the flash state are obtained;

[0074] Based on the gas phase and liquid phase contents of all components of the gasoline sample under flash evaporation, it is determined whether the gasoline sample can reach flash equilibrium under the conditions calculated by the flash evaporation model.

[0075] In the specific implementation process, a gasoline molecule and property database can be established in advance. This database can store molecular component data of various types of gasoline samples, including but not limited to one or more of the following: SMILES descriptor, molecular weight, critical temperature, critical pressure, eccentricity factor, liquid phase molar volume at 25°C, molar fraction, and solubility parameters. When performing subsequent calculations, the molecular component data of the gasoline sample to be tested can be obtained by querying the established gasoline molecule and property database.

[0076] Optionally, under the flash evaporation model calculation conditions, based on the molecular composition data of the gasoline sample to be tested, the gas phase content and liquid phase content of all components of the gasoline sample under flash evaporation state are obtained, including:

[0077] For each component of the gasoline sample to be tested, perform the following operations:

[0078] Step S201: Based on the operating temperature, operating pressure, and molecular composition data of the components, determine the gas phase fugacity coefficient and liquid phase fugacity coefficient of the components under the flash evaporation model calculation conditions.

[0079] Step S202: Determine the phase equilibrium constant of the components under the calculation conditions of the flash evaporation model based on the gas phase fugacity coefficient and the liquid phase fugacity coefficient;

[0080] Step S203: Based on the phase equilibrium constant, the first vaporization fraction, and the molecular composition data of the components, calculate the gas phase content and liquid phase content of the components under flash evaporation.

[0081] Specifically, the flowchart for determining the gas phase and liquid phase contents of the components in the gasoline sample to be tested can be found here. Figure 2As shown, the gas phase fugacity coefficient and liquid phase fugacity coefficient of the component under flash model calculation conditions can be determined based on the operating temperature, operating pressure, and molecular composition data of the component; the phase equilibrium constant of the component under flash model calculation conditions can be determined based on the gas phase fugacity coefficient and liquid phase fugacity coefficient; the equation of state can be the van der Waals equation of state, the Redlich-Kwong equation, the Soave-Redlich-Kwong equation, and the Peng-Robinson equation. For example, the gas phase fugacity coefficient of the i-th component of the gasoline sample to be tested can be obtained by simultaneously solving the SRK (Soave-Redlich-Kwong) equation of state (1) and (2) shown below. and liquid phase fugacity coefficient This allows us to obtain the gas-phase fugacity coefficient and liquid-phase fugacity coefficient for each component.

[0082]

[0083] Among them, Z i Let q be the compressibility factor of the i-th molecular component of the gasoline sample to be tested, a(T) be a function of temperature, T be the operating temperature, R be the gas constant, and q = (Ψ*a(T)). r )) / (Ω*T r ), b=Ω*R*Tc / Pc; σ, ∈, a(T r ), Ψ, and Ω are the basic parameters of the state equations. The basic parameters of the SRK state equations can be obtained from the state equation parameter table shown in Table 1; β=Ω*(P r / T r ), where Tr = T / Tc, Pr = P / Pc, T c P is the critical temperature between the gas and liquid phases; c Where is the critical pressure of the gas phase and the liquid phase, and P is the operating pressure.

[0084] Solving equations (1) and (2) simultaneously, we obtain three solutions. The largest solution is the gas phase fugacity coefficient, the smallest solution is the liquid phase fugacity coefficient, and the intermediate solutions are meaningless. Thus, we can obtain the gas phase fugacity coefficient of the i-th component of the gasoline sample to be tested. and liquid phase fugacity coefficient

[0085] Table 1

[0086]

[0087] In Table 1 above, a SRK (T r ) represents the temperature function of the Soave-Redlich-Kwong equation, aPR (T r ) is the temperature function of the Peng-Robinson equation, and ω is the eccentricity factor.

[0088] Based on the calculated gas-phase and liquid-phase fugacity coefficients of each component of the gasoline sample under test, the phase equilibrium constant of each component under the current flash model calculation conditions can be determined. As an example, the phase equilibrium constant of any component of the gasoline sample under test can be calculated using the following formula:

[0089]

[0090] Among them, K i Let be the phase equilibrium constant of the i-th component of the gasoline sample to be tested; Let be the liquid phase fugacity coefficient of the i-th component of the gasoline sample to be tested; Let be the gas phase fugacity coefficient of the i-th component of the gasoline sample to be tested.

[0091] The following formula can be used to calculate the vapor phase content (x) of each component in the gasoline sample under flash conditions defined by the flash model calculation. i and liquid phase content y i .

[0092]

[0093] Among them, z i K represents the mole fraction of the i-th molecular component in the gasoline sample to be tested. i Let be the phase equilibrium constant of the i-th component of the gasoline sample to be tested; e old This is the first gasification fraction.

[0094] Optionally, based on the gas phase and liquid phase contents of all components of the gasoline sample under flash evaporation, determine whether the gasoline sample can reach flash equilibrium under the conditions calculated by the flash evaporation model, including:

[0095] Determine the difference between the gas phase content and liquid phase content of each component in the gasoline sample to be tested under flash evaporation conditions;

[0096] If the sum of all differences is less than the preset equilibrium threshold, it is determined that the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions;

[0097] If the sum of all differences is not less than the preset equilibrium threshold, it is determined that the gasoline sample to be tested cannot reach the flash equilibrium state under the flash model calculation conditions.

[0098] In the specific implementation process, the phase equilibrium constant of each component of the gasoline sample to be tested, as well as the gas phase content x, can be calculated based on the above calculations. i and liquid phase content y i The Rachford-Rice equation is established as shown in formula (6). If the value of the equation is less than the preset equilibrium threshold, it is determined that the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions. If the value of the equation is not less than the preset equilibrium threshold, it is determined that the gasoline sample to be tested cannot reach the flash equilibrium state under the flash model calculation conditions. The equilibrium threshold can be set to different values ​​according to the type of gasoline to be tested, for example, it can be set to 0.0001.

[0099]

[0100] Optionally, if step S101 determines that the gasoline sample to be tested can reach flash equilibrium under the flash model calculation conditions, step S102 is executed. In step S102, determining the second vaporization fraction of the gasoline sample to be tested under the flash model calculation conditions includes:

[0101] Using the SRK equation of state, the density of the separated mixed gas phase of the gasoline sample under flash equilibrium was calculated when the sample reached flash equilibrium under the flash model calculation conditions.

[0102] Using the improved Rackett equation, the density of the mixed liquid phase separated when the gasoline sample under the flash model reaches flash equilibrium was calculated.

[0103] The second gasification fraction is obtained based on the density of the mixed gas phase and the density of the mixed liquid phase.

[0104] Optionally, using the SRK equation of state, the density of the separated gas phase of the gasoline sample under flash equilibrium is calculated, including:

[0105] The molar volume of the mixed gas phase of the gasoline sample to be tested was obtained using the SRK equation of state.

[0106] Based on the molar volume of the mixed gas phase, the molecular weight and mass content of the molecules in the mixed gas phase of the gasoline sample to be tested, the density of the mixed gas phase separated when the gasoline sample reaches flash equilibrium under the flash model calculation conditions is obtained.

[0107] In the specific implementation process, the molar volume of the mixed gas phase can be obtained using the SRK equation of state as shown in formula (7). The density of the mixed gas phase is obtained using the mixing rule shown in formula (9).

[0108]

[0109] Where Z is the compressibility factor, which can be obtained from the molecular composition data of the gasoline sample to be tested; R is the gas constant; T is the operating temperature; and P is the operating pressure.

[0110] The compression factor can be obtained by the following formula:

[0111]

[0112] Where ω is the eccentricity factor, and B0, B1, and B are the parameters that need to be calculated, which can be obtained according to the corresponding calculation formula in formula (8) above.

[0113]

[0114] Among them, MW i x is the molecular weight of the i-th molecule in the gas mixture; i Let be the mass content of the i-th molecule in the mixed gas phase.

[0115] Optionally, using the modified Rackett equation, the density of the separated liquid phase of the gasoline sample under flash equilibrium conditions is calculated, including:

[0116] The molar volume of the mixed liquid phase of the gasoline sample to be tested was obtained using the improved Rackett equation.

[0117] Based on the molar volume of the mixed liquid phase, the mass content of the components in the mixed liquid phase of the gasoline sample to be tested, and the density of the components, the density of the mixed liquid phase separated when the gasoline sample reaches flash equilibrium under the flash model calculation conditions is obtained.

[0118] In the specific implementation process, the molar volume V of each component in the mixed liquid phase can be calculated using formula (10). s The density ρ of the mixed liquid phase is obtained using the mixing rule shown in formula (11). mix :

[0119]

[0120] Among them, V s T is the molar volume of any component in the mixed liquid phase; c P is the critical temperature of this component; c ω is the critical pressure; T is the operating temperature; ω is the eccentricity factor.

[0121]

[0122] Where, x wiρ represents the mass content of the i-th component in the mixed liquid phase. i The density of the i-th component in the mixed liquid phase can be obtained based on the molecular weight of each component in the mixed liquid phase.

[0123] After calculating the density of the mixed gas phase and the mixed liquid phase of the gasoline sample to be tested, the second vaporization fraction e of the gasoline sample under the flash evaporation state can be calculated according to formula (12). new .

[0124]

[0125] Where, ρ LF The density of the gasoline sample to be tested at the operating temperature determined for the Reid vapor pressure test experiment; MW V The molecular weight of the gas mixture can be calculated based on the molecular composition data of the gasoline sample being tested; MW L The molecular weight of the mixed liquid phase can be calculated based on the molecular composition data of the gasoline sample to be tested.

[0126] Optionally, if step S101 determines that the gasoline sample to be tested cannot reach flash equilibrium under the flash model calculation conditions, step S103 is executed. In step S103, the operating pressure in the flash model calculation conditions is adjusted using a preset pressure adjustment rule, including:

[0127] The operating pressure in the calculation conditions of the flash evaporation model was adjusted using an adjustment algorithm.

[0128] or;

[0129] Determine the pressure adjustment amount according to the preset pressure adjustment ratio, and adjust the operating pressure in the flash evaporation model calculation conditions based on the pressure adjustment amount.

[0130] Specifically, the operating pressure in the flash model calculation conditions can be adjusted iteratively multiple times using Newton's iteration method, or the pressure adjustment amount can be determined based on the pressure adjustment ratio, and the operating pressure in the current flash model calculation conditions can be iteratively adjusted based on the pressure adjustment amount to obtain the adjusted flash model calculation conditions. At this time, the flash model calculation conditions include: operating temperature, adjusted operating pressure, and first vaporization fraction. Then, step S101 is executed again to determine whether the gasoline sample to be tested can reach the flash equilibrium state under the adjusted flash model calculation conditions, until the gasoline sample to be tested can reach the flash equilibrium state under the adjusted flash model calculation conditions, and the second vaporization fraction is calculated.

[0131] Optionally, if, according to step S104 above, the difference between the second gasification fraction and the first gasification fraction is not less than a preset precision, step S106 is executed. In step S106, the first gasification fraction in the flash model calculation conditions is adjusted according to a preset gasification fraction adjustment rule, including:

[0132] Adjust the value of the first gasification fraction based on the value of the second gasification fraction;

[0133] or;

[0134] According to the preset differentiation rate adjustment ratio, determine the differentiation rate adjustment amount, and adjust the first gasification fraction in the flash evaporation model calculation conditions based on the differentiation rate adjustment amount.

[0135] In the specific implementation process, in the second gasification fraction (e new ) and the first gasification fraction (e old If the difference between the two is not less than the preset accuracy, it can be considered that a flash equilibrium state can be reached under the current flash model calculation conditions. The value of the first vaporization fraction can be adjusted based on the value of the second vaporization fraction to obtain the adjusted flash model calculation conditions. For example, the value of the second vaporization fraction can be used as the value of the first vaporization fraction in the flash model calculation conditions; or, the amount of differentiation rate adjustment can be determined according to the preset differentiation rate adjustment ratio, and the first vaporization fraction in the flash model calculation conditions can be adjusted based on the differentiation rate adjustment amount to obtain the adjusted flash model calculation conditions. The flash model calculation conditions at this time include: operating temperature, adjusted operating pressure, and adjusted first vaporization fraction. Under the adjusted flash model calculation conditions, steps S101-S104 are repeated until the difference between the first vaporization fraction and the second vaporization fraction is less than the preset accuracy, thus obtaining the Reid vapor pressure of the gasoline sample to be tested.

[0136] If, according to step S104, the difference between the second gasification fraction and the first gasification fraction is less than the preset precision, it can be considered that a flash evaporation equilibrium state can be achieved under the current flash evaporation model calculation conditions.

[0137] Based on the same inventive concept, embodiments of the present invention also provide a gasoline red vapor pressure prediction device, which can be installed in a device with processing and computing capabilities, and the structure of the device is as follows. Figure 3 As shown, it includes:

[0138] The first judgment module 10 is used to determine whether the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions based on the molecular composition data of the gasoline sample to be tested. The flash model calculation conditions include: operating temperature, first vaporization fraction and operating pressure.

[0139] The first adjustment module 11 is used to adjust the operating pressure in the flash model calculation conditions using a preset pressure adjustment rule when the first judgment module determines that the gasoline sample to be tested cannot reach the flash equilibrium state, and to notify the first judgment module to continue to execute the step of judging whether the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions.

[0140] The vaporization fraction determination module 12 is used to determine the second vaporization fraction of the gasoline sample under the flash model calculation conditions when the first judgment module determines that the gasoline sample to be tested can reach the equilibrium state.

[0141] The second judgment module 13 is used to determine whether the difference between the second gasification fraction and the first gasification fraction is less than a preset precision.

[0142] The second adjustment module 14 is used to adjust the first vaporization fraction in the flash model calculation conditions according to the preset vaporization fraction adjustment rules when the second judgment module determines that the difference between the second vaporization fraction and the first vaporization fraction is not less than the preset accuracy, and to notify the first judgment module to continue to execute the step of judging whether the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions.

[0143] The pressure determination module 15 is used to take the operating pressure in the current flash model calculation conditions as the Reid vapor pressure of the gasoline sample to be tested when the second judgment module determines that the difference between the second vaporization fraction and the first vaporization fraction is less than the preset accuracy.

[0144] Regarding the gasoline red vapor pressure prediction device in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated here.

[0145] The method and apparatus described in this embodiment of the invention determine whether the gasoline sample can reach flash equilibrium under flash model calculation conditions based on its molecular composition data. If it cannot reach flash equilibrium, the operating pressure in the flash model calculation conditions is adjusted using preset pressure adjustment rules, and the step of determining whether the gasoline sample can reach flash equilibrium under flash model calculation conditions is continued. Multiple iterations of pressure adjustment reduce errors and make the prediction results more accurate. This method does not require establishing a database for modeling and prediction. For each gasoline sample to be tested, it can be based on the molecular composition data of the gasoline sample. This method uses molecular composition data to calculate the parameters required for the Reid vapor pressure of gasoline. If an equilibrium state can be reached, the second vaporization fraction of the gasoline sample under flash model calculation conditions is determined. The difference between the second and first vaporization fractions is checked against a preset precision. If the difference is not less than the preset precision, the first vaporization fraction in the flash model calculation conditions is adjusted according to a preset vaporization fraction adjustment rule. The process continues to determine whether the gasoline sample can reach flash equilibrium under the flash model calculation conditions. The first vaporization fraction is iteratively adjusted multiple times to reduce the error between the first and second vaporization fractions, improving prediction accuracy. If the difference is less than the preset precision, the operating pressure in the current flash model calculation conditions is used as the Reid vapor pressure of the gasoline sample. This method can further calculate the required Reid vapor pressure based on the molecular composition data of the gasoline sample itself. It is universally applicable to various gasoline samples and can accurately and quickly obtain the Reid vapor pressure of the gasoline sample, providing strong technical support for actual industrial production.

[0146] This invention also provides a computer storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described gasoline red vapor pressure prediction method.

[0147] This invention also provides a terminal device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the above-described gasoline Reid vapor pressure prediction method.

[0148] Unless otherwise specifically stated, terms such as processing, calculation, operation, determination, display, etc., may refer to the actions and / or processes of one or more processing or computing systems or similar devices that represent the manipulation and conversion of data representing physical (e.g., electronic) quantities within the registers or memory of the processing system into other data similarly representing physical quantities within the memory, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals can be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0149] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0150] In the detailed description above, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features in a single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, with each claim representing a separate preferred embodiment of the invention.

[0151] Those skilled in the art will also understand that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments herein can be implemented as electronic hardware, computer software, or a combination thereof. To clearly illustrate the interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps described above are generally described in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art can implement the described functionality in alternative ways for each specific application; however, such implementation decisions should not be construed as departing from the scope of this disclosure.

[0152] The steps of the methods or algorithms described in conjunction with the embodiments herein can be directly embodied in hardware, software modules executed by a processor, or a combination thereof. The software modules can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. The ASIC can reside in a user terminal. Alternatively, the processor and storage medium can exist as discrete components in the user terminal.

[0153] For software implementation, the techniques described in this application can be implemented using modules (e.g., procedures, functions, etc.) that perform the functions described in this application. This software code can be stored in memory units and executed by a processor. The memory units can be implemented within the processor or outside the processor; in the latter case, they are communicatively coupled to the processor via various means, as is well known in the art.

[0154] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

Claims

1. A method for predicting gasoline Reid vapor pressure, characterized in that, include: Based on the molecular composition data of the gasoline sample to be tested, it is determined whether the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions. The flash model calculation conditions include: operating temperature, first vaporization fraction and operating pressure. If flash evaporation cannot reach equilibrium, the operating pressure in the flash evaporation model calculation conditions is adjusted using the preset pressure adjustment rules, and the step of determining whether the gasoline sample to be tested can reach flash evaporation equilibrium under the flash evaporation model calculation conditions is continued; if equilibrium can be reached, the second vaporization fraction of the gasoline sample to be tested under the flash evaporation model calculation conditions is determined. Determine whether the difference between the second vaporization fraction and the first vaporization fraction is less than the preset precision. If it is not less than the preset precision, adjust the first vaporization fraction in the flash model calculation conditions according to the preset vaporization fraction adjustment rules, and continue to execute the step of determining whether the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions. If it is less than the preset precision, use the operating pressure in the current flash model calculation conditions as the Reid vapor pressure of the gasoline sample to be tested.

2. The method as described in claim 1, characterized in that, The step of determining whether the gasoline sample to be tested can reach flash equilibrium under the flash model calculation conditions, based on the molecular composition data of the gasoline sample to be tested, includes: Under the flash evaporation model calculation conditions, based on the molecular composition data of the gasoline sample to be tested, the gas phase content and liquid phase content of all components of the gasoline sample to be tested under flash evaporation conditions are obtained. Based on the gas phase and liquid phase contents of all components of the gasoline sample under flash evaporation, it is determined whether the gasoline sample can reach flash equilibrium under the conditions calculated by the flash evaporation model.

3. The method as described in claim 2, characterized in that, Under the flash evaporation model calculation conditions, based on the molecular composition data of the gasoline sample to be tested, the gas phase content and liquid phase content of all components of the gasoline sample to be tested under flash evaporation conditions are obtained, including: For each component of the gasoline sample to be tested, the following operations are performed: Based on the operating temperature, operating pressure, and molecular composition data of the components, the gas phase fugacity coefficient and liquid phase fugacity coefficient of the components are determined under the flash evaporation model calculation conditions. Based on the gas phase fugacity coefficient and the liquid phase fugacity coefficient, determine the phase equilibrium constant of the component under the calculation conditions of the flash evaporation model; Based on the phase equilibrium constant and the first vaporization fraction, as well as the molecular composition data of the components, the gas phase content and liquid phase content of the components in the flash evaporation state are calculated.

4. The method as described in claim 2, characterized in that, Based on the gas phase and liquid phase contents of all components of the gasoline sample under flash evaporation, determine whether the gasoline sample can reach flash equilibrium under the conditions calculated by the flash evaporation model, including: Determine the difference between the gas phase content and liquid phase content of each component in the gasoline sample to be tested under the flash evaporation state; If the sum of all differences is less than the preset equilibrium threshold, it is determined that the gasoline sample to be tested can reach the flash equilibrium state under the calculation conditions of the flash model. If the sum of all differences is not less than the preset equilibrium threshold, it is determined that the gasoline sample to be tested cannot reach flash equilibrium under the flash model calculation conditions.

5. The method as described in claim 1, characterized in that, Determining the second vaporization fraction of the gasoline sample under flash model calculation conditions includes: Using the SRK equation of state, the density of the mixed gas phase separated when the gasoline sample under test reaches flash equilibrium under the flash model calculation conditions is calculated. Using the improved Rackett equation, the density of the mixed liquid phase separated when the gasoline sample under test reaches flash equilibrium under the flash model calculation conditions was calculated. The second gasification fraction is obtained based on the density of the mixed gas phase and the density of the mixed liquid phase.

6. The method as described in claim 5, characterized in that, The density of the separated gas phase in the gasoline sample under flash equilibrium, calculated using the SRK equation of state, includes: The molar volume of the mixed gas phase of the gasoline sample to be tested was obtained using the SRK equation of state. Based on the molar volume of the mixed gas phase, the molecular weight and mass content of the molecules in the mixed gas phase of the gasoline sample to be tested, the density of the mixed gas phase separated when the gasoline sample to be tested reaches the flash equilibrium state under the flash model calculation conditions is obtained.

7. The method as described in claim 5, characterized in that, The density of the separated liquid phase of the gasoline sample under flash equilibrium, calculated using the improved Rackett equation, includes: The molar volume of the mixed liquid phase of the gasoline sample to be tested was obtained using the improved Rackett equation. Based on the molar volume of the mixed liquid phase, the mass content of the components in the mixed liquid phase of the gasoline sample to be tested, and the density of the components, the density of the mixed liquid phase separated when the gasoline sample to be tested reaches the flash equilibrium state under the flash model calculation conditions is obtained.

8. The method as described in claim 1, characterized in that, Adjusting the operating pressure in the flash evaporation model calculation conditions using preset pressure adjustment rules includes: The operating pressure in the calculation conditions of the flash evaporation model was adjusted using an adjustment algorithm. or; According to the preset pressure adjustment ratio, determine the pressure adjustment amount, and adjust the operating pressure in the flash evaporation model calculation conditions based on the pressure adjustment amount.

9. The method as described in claim 1, characterized in that, The adjustment of the first gasification fraction in the flash evaporation model calculation conditions according to the preset gasification fraction adjustment rules includes: Adjust the value of the first gasification fraction according to the value of the second gasification fraction; or; According to the preset differentiation rate adjustment ratio, determine the differentiation rate adjustment amount, and adjust the first gasification fraction in the flash evaporation model calculation conditions based on the differentiation rate adjustment amount.

10. A gasoline red vapor pressure prediction device, characterized in that, include: The first judgment module is used to determine whether the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions based on the molecular composition data of the gasoline sample to be tested. The flash model calculation conditions include: operating temperature, first vaporization fraction and operating pressure. The first adjustment module is used to adjust the operating pressure in the flash model calculation conditions using a preset pressure adjustment rule when the first judgment module determines that the gasoline sample to be tested cannot reach the flash equilibrium state. It then notifies the first judgment module to continue executing the step of judging whether the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions. The vaporization fraction determination module is used to determine the second vaporization fraction of the gasoline sample under the flash model calculation conditions when the first judgment module determines that the gasoline sample to be tested can reach the equilibrium state. The second judgment module is used to determine whether the difference between the second gasification fraction and the first gasification fraction is less than the preset precision. The second adjustment module is used to adjust the first vaporization fraction in the flash model calculation conditions according to the preset vaporization fraction adjustment rules when the second judgment module determines that the difference between the second vaporization fraction and the first vaporization fraction is not less than the preset accuracy, and to notify the first judgment module to continue to execute the step of judging whether the gasoline sample to be tested can reach the flash equilibrium state under the flash model calculation conditions. The pressure determination module is used to take the operating pressure in the current flash model calculation conditions as the Reid vapor pressure of the gasoline sample to be tested when the second judgment module determines that the difference between the second vaporization fraction and the first vaporization fraction is less than the preset accuracy.

11. A computer storage medium, characterized in that, The computer storage medium stores computer-executable instructions, which, when executed by a processor, implement the gasoline red vapor pressure prediction method according to any one of claims 1-9.

12. A prediction device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the gasoline Reid vapor pressure prediction method according to any one of claims 1-9.

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