Dynamic pH calculation method of high-temperature and high-pressure water vapor system and related device

Abstract

The invention discloses a pH dynamic calculation method of a high-temperature and high-pressure water vapor system and a related device. The method comprises the following steps: acquiring the temperature T, the pressure P and the total substance concentration CT, i of a water sample in the high-temperature and high-pressure water vapor system; constructing a pH calculation model, wherein the pH calculation model is constructed based on introduction of multiple balance coupling, a dynamic activity correction factor and a temperature-pressure adaptive ionization constant model; the temperature T, the pressure P and the total substance concentration CT, i of the water sample in the high-temperature and high-pressure water vapor system are input into a pH calculation model, the pH value of the water sample in the high-temperature and high-pressure water vapor system is obtained, and the method and the related device can accurately calculate the pH value of the water sample.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of environmental chemistry and thermodynamics, and relates to a method and related apparatus for dynamic pH calculation of a high-temperature and high-pressure water vapor system. Background Technology

[0002] Currently, power systems mostly use traditional glass electrodes (potential type) to detect pH levels in water-steam systems. However, the accuracy of this method for detecting low-conductivity water samples is difficult to guarantee, with the accuracy of online pH meters in most generator sets' water-steam systems even falling below 40%. This is because potentiometric instruments are subject to interference from various pure water factors and online factors when measuring the pH of low-conductivity water samples. The main interfering factors include liquid junction potential, flow potential, temperature changes, degradation of the electrode glass film, and liquid seepage into the reference electrode. Therefore, ASTM, VGB, and domestic power standards recommend that the pH value of low-conductivity water samples in generator set water-steam systems be obtained through calculation. Traditional calculation models rely on the conductivity of cooled water samples, which is a rough empirical model. It does not consider the gas-liquid distribution of volatile substances such as CO2 and NH3, assumes that Kw (water dissociation constant) is a fixed value, and does not introduce temperature-pressure coupling correction. When using the Davies equation to process high ionic strength solutions, the error is significant, making it unsuitable for accurate pH calculation and leading to measurement deviations. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method and related device for dynamic pH calculation of a high-temperature and high-pressure water vapor system. This method and related device can accurately calculate the pH value of a water sample.

[0004] To achieve the above objectives, this invention discloses a method for dynamic pH calculation of a high-temperature, high-pressure water vapor system, comprising:

[0005] Obtain the temperature (T), pressure (P), and total concentration (C) of a water sample from a high-temperature, high-pressure water-steam system. T,i ;

[0006] A pH calculation model is constructed based on the introduction of multiple equilibrium couplings, dynamic activity correction factors, and temperature-pressure adaptive ionization constant models.

[0007] The temperature T, pressure P, and total substance concentration C of the water sample in the high-temperature and high-pressure water vapor system were determined. T,i The pH value of the water sample obtained from the high-temperature and high-pressure water vapor system is input into the pH calculation model.

[0008] A further improvement of the pH dynamic calculation method for the high-temperature and high-pressure water vapor system described in this invention is as follows:

[0009] Furthermore, the temperature T, pressure P, and total substance concentration C of the water sample in the high-temperature, high-pressure water-steam system are...T,i The pH value of the water sample obtained from the high-temperature and high-pressure water vapor system is input into the pH calculation model.

[0010] Based on the water sample's temperature T, pressure P, and total substance concentration C T,i The concentrations of each phase in a water sample are calculated using the phase distribution formula.

[0011] The concentration of hydrogen ions in the water sample is calculated using the proton conservation formula based on the concentrations of each phase in the water sample.

[0012] The pH value of a water sample is determined based on the concentration of hydrogen ions in the sample.

[0013] Furthermore, the phase allocation formula is expressed as:

[0014]

[0015] in, H i (T,P) is Henry's constant, γ i This is the activity coefficient.

[0016] Furthermore, the proton conservation formula can be expressed as:

[0017]

[0018] Furthermore, the method based on the water sample's temperature T, pressure P, and total substance concentration C... T，i The process of calculating the concentration of each phase in a water sample using the phase distribution formula is as follows:

[0019] The Newton-Raphson iterative algorithm is accelerated using the Broyden matrix, based on the water sample's temperature T, pressure P, and total concentration C. T,i The concentrations of each phase in the water sample are calculated using the phase distribution formula.

[0020] This invention discloses a dynamic pH calculation system for a high-temperature, high-pressure water vapor system, comprising:

[0021] The acquisition module is used to acquire the temperature T, pressure P, and total substance concentration C of a water sample in a high-temperature, high-pressure water-steam system. T,i ;

[0022] The module is used to build a pH calculation model, which is based on a model that incorporates multiple equilibrium couplings, dynamic activity correction factors, and temperature-pressure adaptive ionization constants.

[0023] The calculation module is used to calculate the temperature T, pressure P, and total substance concentration C of the water sample in the high-temperature and high-pressure water-steam system. T,i The pH value of the water sample obtained from the high-temperature and high-pressure water vapor system is input into the pH calculation model.

[0024] The further improvement of the pH dynamic calculation system of the high-temperature and high-pressure water vapor system lies in that:

[0025] Further, the temperature T, pressure P and total material concentration C of the water sample in the high-temperature and high-pressure water vapor system are input into a pH calculation model to obtain the pH value of the water sample in the high-temperature and high-pressure water vapor system. T,i

[0026] According to the temperature T, pressure P and total material concentration C of the water sample, T,i the phase concentration of the water sample is calculated by using a phase distribution formula;

[0027] According to the phase concentration of the water sample, the concentration of hydrogen ions in the water sample is calculated by using a proton conservation formula;

[0028] The pH value of the water sample is determined according to the concentration of hydrogen ions in the water sample.

[0029] Further, the phase distribution formula is represented as:

[0030]

[0031] wherein, H i (T, P) is a Henry constant, and γ i is an activity coefficient.

[0032] The application discloses a computer device, which comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the pH dynamic calculation method of the high-temperature and high-pressure water vapor system when executing the computer program.

[0033] The application discloses a computer readable storage medium, which stores a computer program, and the computer program implements the steps of the pH dynamic calculation method of the high-temperature and high-pressure water vapor system when executed by a processor.

[0034] The application has the following beneficial effects:

[0035] The pH dynamic calculation method of the high-temperature and high-pressure water vapor system and the related device have the following beneficial effects: T,i The temperature T, pressure P and total material concentration C of the water sample in the high-temperature and high-pressure water vapor system are input into a pH calculation model to obtain the pH value of the water sample in the high-temperature and high-pressure water vapor system, and the pH calculation model is constructed based on the introduction of a plurality of balance coupling, a dynamic activity correction factor and a temperature-pressure adaptive ionization constant model, so that the pH value of the water sample under low-temperature and low-pressure conditions can be calculated, the pH value of the water sample under high-temperature and high-pressure conditions can be calculated, and the calculation accuracy and speed are significantly improved. BRIEF DESCRIPTION OF DRAWINGS​

[0036] The accompanying drawings, which form a part of this specification, are included to provide a further understanding of the application, and are incorporated into and constitute a part of this specification. The drawings illustrate one illustrative embodiment of the application and, together with the description, serve to explain the application.

[0037] Figure 1 Flow chart of the method of the present application. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0039] In the description of the present application, it should be understood that the terms "comprising" and "including" indicate the presence of described features, integers, steps, operations, elements, and / or components, but do not exclude one or more other features, integers, steps, operations, elements, components, and / or sets thereof.

[0040] It should also be understood that the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and the appended claims of the present application, the singular forms "a", "an" and "the" are intended to include the plural forms, unless the context clearly indicates otherwise.

[0041] It should be further understood that the term "and / or" used in the specification and the appended claims of the present application means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations, for example, A and / or B can represent three cases of A alone, A and B together, and B alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects.

[0042] It should be understood that although the terms first, second, third, etc. may be used in the embodiments of the present application to describe the preset ranges, etc., these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from each other. For example, the first preset range can also be referred to as the second preset range, and similarly, the second preset range can also be referred to as the first preset range, without departing from the scope of the embodiments of the present application.

[0043] Depending on the context, the word "if" as used herein can be interpreted to mean "when" or "while" or "in response to determining" or "in response to detecting." Similarly, the phrase "if it is determined" or "if [a stated condition or event] is detected" can be interpreted to mean "when it is determined" or "in response to determining" or "when [the stated condition or event] is detected" or "in response to detecting [the stated condition or event]."

[0044] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art without creative work based on the embodiments in the present application fall within the scope of protection of the present application.

[0045] Various structural schematic diagrams according to the disclosed embodiments of the present application are shown in the drawings. These diagrams are not drawn to scale, in which some details are exaggerated for the purpose of clarity and some details can be omitted. The shapes of various regions, layers and the relative size and position relationship therebetween shown in the drawings are only exemplary, and in actuality, there can be deviations due to manufacturing tolerances or technical limitations, and regions / layers with different shapes, sizes and relative positions can be additionally designed by those skilled in the art according to actual needs.

[0046] Embodiment one

[0047] The present application introduces a plurality of balanced coupling, dynamic activity correction factor, temperature-pressure adaptive ionization constant model and other contents, which can not only calculate the pH value of low-temperature and low-pressure water sample, but also calculate the pH under high-temperature and high-pressure conditions, and the calculation accuracy and speed are significantly improved.

[0048] The pH dynamic calculation method of the high-temperature and high-pressure water vapor system according to the present application comprises the following steps:

[0049] 1) Establish a multiphase balance coupling model

[0050] The gas-liquid-solid three-phase material conservation equation is established:

[0051]

[0052] wherein, H i is the temperature-pressure corrected Henry's constant, Ss,i For solid solubility.

[0053] 2) Introducing dynamic activity correction factor

[0054] The activity equation based on local composition theory is:

[0055]

[0056] Where θ ij is the ion pair interaction parameter, optimized by quantum chemistry calculation.

[0057] 3) Building temperature-pressure adaptive Kw model

[0058] The temperature-pressure adaptive Kw model is established by molecular dynamics simulation:

[0059]

[0060] The specific process is:

[0061] 1) Building a multi-substance balance model

[0062] 11) Gas-liquid distribution (Henry's law correction)

[0063] For volatile substances i, such as CO2 and NH3, the gas-liquid distribution relationship needs to consider the influence of temperature T and pressure P:

[0064]

[0065] Henry's constant H i (T, p) is:

[0066]

[0067] Where H i,0 is the Henry's constant under standard conditions; ΔH sol is the dissolution enthalpy, and β is the pressure correction coefficient.

[0068] 2) Solid phase precipitation equilibrium (solubility product correction)

[0069] For solid phase precipitation, the dissolution equilibrium is:

[0070]

[0071] The solubility product temperature lnK sp,s is:

[0072]

[0073] Where v i is the stoichiometric number, and ΔH dissDissolution enthalpy.

[0074] 3) Total mass conservation equation

[0075] Total concentration of each species in the system C T,i Composed of liquid, gas and solid phases, i.e.

[0076]

[0077] Where S s,i represents the mole ratio of component i in the solid phase s, for example, Ca in CaCO2 2+ : CO2 2- = 1:1.

[0078] 2) Construct a dynamic activity correction factor model;

[0079] 21) Extended local composition activity model;

[0080] Activity coefficient γi is determined by electrostatic interaction and ion pair effect, i.e.

[0081]

[0082] Where A = 0.5085, B = 0.3281A °-1 ; Θ Ij is the ion pair parameter optimized by quantum chemical calculation; α is the temperature attenuation coefficient, with an empirical value of about 0.01-0.03 K-1.

[0083] 22) Ion strength I is:

[0084]

[0085] 3) Construct a temperature-pressure adaptive water dissociation constant Kw calculation model, where Kw is:

[0086]

[0087] 4) Construct a pH calculation model;

[0088] 41) Based on proton conservation;

[0089]

[0090] 42) Simultaneous solution step;

[0091] Collect the temperature T, pressure P, total material concentration C T,i , mass transfer coefficient K vol,i of the water sample;

[0092] Initialization: Assume the gas phase partial pressure P i , i.e. the solid phase concentration S s,i;

[0093] The Newton-Raphson iterative algorithm is accelerated by Broyden matrix, wherein the iterative solving process is as follows:

[0094] a) calculating the phase distribution

[0095] b) updating the activity coefficient γi and Kw;

[0096] c) calculating [H + ] by the charge balance equation;

[0097] d) correcting Pi and Ss,i by using Broyden method;

[0098]

[0099] e) the convergence condition is: max[ΔC aq，i ]<10 -5 mol / L.

[0100] For example, the water sample parameters of a water sample are collected: temperature T=300℃, pressure P=10MPa

[0101] The initial concentration is: C T,CO2 =0.5mol / L, C T,NaCl =0.1mol / L

[0102] According to the model output result: [H + ]=2.0×10 -5 mol / L→pH=4.7;

[0103] The CO2 gas phase partial pressure P CO2 =1.2MPa, and the volatile amount accounts for 28%;

[0104] The solid phase precipitates about 0.02mol / L.

[0105] Example two

[0106] The pH dynamic calculation system of the high-temperature and high-pressure water vapor system, comprising:

[0107] An acquisition module is configured to acquire the temperature T, pressure P and total material concentration C T,i of a water sample in a high-temperature and high-pressure water vapor system.

[0108] A construction module is configured to construct a pH calculation model.

[0109] A calculation module is configured to calculate the temperature T, pressure P and total material concentration C T,iThe pH value of the water sample obtained from the high-temperature and high-pressure water vapor system is input into the pH calculation model.

[0110] In this embodiment, the temperature T, pressure P, and total substance concentration C of the water sample in the high-temperature and high-pressure water vapor system are used. T,i The pH value of the water sample obtained from the high-temperature and high-pressure water vapor system is input into the pH calculation model.

[0111] Based on the water sample's temperature T, pressure P, and total substance concentration C T,i The concentrations of each phase in a water sample are calculated using the phase distribution formula.

[0112] The concentration of hydrogen ions in the water sample is calculated using the proton conservation formula based on the concentrations of each phase in the water sample.

[0113] The pH value of a water sample is determined based on the concentration of hydrogen ions in the sample.

[0114] In this embodiment, the phase allocation formula is expressed as:

[0115]

[0116] in, H i (T,P) is Henry's constant, γ i This is the activity coefficient.

[0117] The module division in this embodiment is illustrative and represents only one logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in each embodiment of this application can be integrated into a single processor, exist as separate physical entities, or be integrated into a single module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0118] Example 3

[0119] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of a method for dynamically calculating the pH of a high-temperature, high-pressure water vapor system. For example, this includes: obtaining the temperature T, pressure P, and total substance concentration C of a water sample from the high-temperature, high-pressure water vapor system. T,i Construct a pH calculation model; ... T,iThe temperature T, the pressure P and the total material concentration C of the water sample in the high-temperature and high-pressure water vapor system are input into the pH calculation model to obtain the pH value of the water sample in the high-temperature and high-pressure water vapor system. The memory can include a memory, such as a high-speed random memory, and can also include a non-volatile memory, such as at least one disk memory and the like; the processor, the network interface, and the memory are connected to each other through an internal bus, which can be an industry standard architecture bus, a peripheral component interconnect standard bus, an extended industry standard structure bus, or the like, and the bus can be divided into an address bus, a data bus, a control bus, and the like. The memory is used to store programs, specifically, the programs can include program codes, and the program codes include computer operation instructions. The memory can include a memory and a non-volatile memory, and provide instructions and data for the processor.

[0120] Embodiment four

[0121] A computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the steps of the pH dynamic calculation method of the high-temperature and high-pressure water vapor system, for example, including: obtaining the temperature T, the pressure P and the total material concentration C of the water sample in the high-temperature and high-pressure water vapor system T,i ; constructing a pH calculation model; inputting the temperature T, the pressure P and the total material concentration C of the water sample in the high-temperature and high-pressure water vapor system T,i into the pH calculation model to obtain the pH value of the water sample in the high-temperature and high-pressure water vapor system. Specifically, the computer readable storage medium includes but is not limited to, for example, a volatile memory and / or a non-volatile memory. The volatile memory can include a random access memory (RAM) and / or a cache memory, and the like. The non-volatile memory can include a read-only memory (ROM), a hard disk, a flash memory, an optical disk, a magnetic disk, and the like.

[0122] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROMs, optical storage, and the like) containing computer-usable program code.

[0123] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0124] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0125] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0126] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0127] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

[0128] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for dynamically calculating pH in a high-temperature, high-pressure water-vapor system, characterized in that, include: Obtain the temperature (T), pressure (P), and total concentration (C) of a water sample from a high-temperature, high-pressure water-steam system. T,i ; A pH calculation model is constructed based on the introduction of multiple equilibrium couplings, dynamic activity correction factors, and temperature-pressure adaptive ionization constant models. The temperature T, pressure P, and total substance concentration C of the water sample in the high-temperature and high-pressure water vapor system were determined. T,i The pH value of the water sample obtained from the high-temperature and high-pressure water vapor system is input into the pH calculation model.

2. The method for dynamic pH calculation of a high-temperature, high-pressure water vapor system according to claim 1, characterized in that, The temperature T, pressure P, and total substance concentration C of the water sample in the high-temperature and high-pressure water vapor system were determined. T,i The pH value of the water sample obtained from the high-temperature and high-pressure water vapor system is input into the pH calculation model. Based on the water sample's temperature T, pressure P, and total substance concentration C T,i The concentrations of each phase in a water sample are calculated using the phase distribution formula. The concentration of hydrogen ions in the water sample is calculated using the proton conservation formula based on the concentrations of each phase in the water sample. The pH value of a water sample is determined based on the concentration of hydrogen ions in the sample.

3. The method for dynamic pH calculation of a high-temperature, high-pressure water vapor system according to claim 1, characterized in that, The phase distribution formula is expressed as follows: in, H i (T,P) is Henry's constant, γ i This is the activity coefficient.

4. The method for dynamic pH calculation of a high-temperature, high-pressure water vapor system according to claim 1, characterized in that, The proton conservation formula is expressed as:

5. The method for dynamic pH calculation of a high-temperature, high-pressure water vapor system according to claim 1, characterized in that, The parameters are based on the water sample's temperature T, pressure P, and total substance concentration C. T,i The process of calculating the concentration of each phase in a water sample using the phase distribution formula is as follows: The Newton-Raphson iterative algorithm is accelerated using the Broyden matrix, based on the water sample's temperature T, pressure P, and total concentration C. T,i The concentrations of each phase in the water sample are calculated using the phase distribution formula.

6. A pH dynamic calculation system for a high-temperature, high-pressure water vapor system, characterized in that, include: The acquisition module is used to acquire the temperature T, pressure P, and total substance concentration C of a water sample in a high-temperature, high-pressure water-steam system. T,i ; The module is used to build a pH calculation model, which is based on a model that incorporates multiple equilibrium couplings, dynamic activity correction factors, and temperature-pressure adaptive ionization constants. The calculation module is used to calculate the temperature T, pressure P, and total substance concentration C of the water sample in the high-temperature and high-pressure water-steam system. T,i The pH value of the water sample obtained from the high-temperature and high-pressure water vapor system is input into the pH calculation model.

7. The pH dynamic calculation system for a high-temperature, high-pressure water vapor system according to claim 6, characterized in that, The temperature T, pressure P, and total substance concentration C of the water sample in the high-temperature and high-pressure water vapor system were determined. T,i The pH value of the water sample obtained from the high-temperature and high-pressure water vapor system is input into the pH calculation model. Based on the water sample's temperature T, pressure P, and total substance concentration C T,i The concentrations of each phase in a water sample are calculated using the phase distribution formula. The concentration of hydrogen ions in the water sample is calculated using the proton conservation formula based on the concentrations of each phase in the water sample. The pH value of a water sample is determined based on the concentration of hydrogen ions in the sample.

8. The pH dynamic calculation system for a high-temperature, high-pressure water vapor system according to claim 7, characterized in that, The phase distribution formula is expressed as follows: in, H i (T,P) is Henry's constant, γ i This is the activity coefficient.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the pH dynamic calculation method for the high-temperature and high-pressure water vapor system as described in any one of claims 1-5.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the pH dynamic calculation method for the high-temperature and high-pressure water vapor system as described in any one of claims 1-5.

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