Method and system for measuring the precipitation rate of inorganic salts in water, electronic device, and storage medium

Abstract

The present invention discloses a method and system for measuring the precipitation rate of inorganic salts in water, an electronic device, and a storage medium. The method includes steps S1, S2, and S3. The steps include: (1) acquiring the type of precipitated inorganic salt in the sample water; (2) acquiring the inorganic carbon methyl orange alkalinity (Cmalk); (3) acquiring the initial content of the target inorganic salt; (4) acquiring the initial content of the target inorganic salt; (5) acquiring the carbon dioxide concentration (CO2w) or its equilibrium gas-phase carbon dioxide concentration (PCO2) in the sample water in a sealed, constant-temperature, constant-pressure environment; (6) acquiring the amount of precipitated target inorganic salt based on the data acquired in steps S1 and S2; and (7) acquiring the precipitation rate of the target inorganic salt based on the amount of precipitate acquired in step S3. The present invention provides a method for measuring the precipitation rate of inorganic salts in water with minimal manual intervention, a low lower limit of quantification, and high accuracy.

Description

[Technical Field]

[0001] The present invention relates to the technical field of water treatment, and in particular to a method and system for measuring the precipitation rate of inorganic salts in water, an electronic device, and a storage medium. [Background technology]

[0002] Scale is defined as an undesirable layer of hard salts that forms on the surface of an object. Such surfaces can include the surfaces of heat exchangers, water pipes, or vessels, as well as the surfaces of rock pores, films, and film pores. Excessive scale buildup can lead to reduced heat exchange efficiency, increased discharge pressure and energy consumption, reduced oil recovery rates, and damage to related oil field equipment, as well as reduced efficiency of reverse osmosis membranes and damage to equipment. The main chemical methods used to inhibit scale include adjusting the supersaturation of scale-forming inorganic salts and adding scale inhibitors to inhibit the precipitation of inorganic salts. The most commonly used mechanism for inhibiting scale is to control the crystallization reaction of these salts, i.e., the amount and rate of their precipitation in water. By combining water quality parameters, operating conditions such as temperature, and the solubility product constant of the inorganic salt, the main type of scale can be determined, the supersaturation can be calculated, and a method designed to adjust the crystallization reaction characteristics of the target inorganic salt can then be verified in the laboratory for practical use. One of the main steps in laboratory verification and actual use is to measure the amount and rate of precipitation of target inorganic salts in water. Hereinafter, the process of measuring the amount and rate of precipitation of target inorganic salts in water in the laboratory will be referred to as Process 1, and the process of measuring the amount and rate of precipitation of inorganic salts in water when used in the field will be referred to as Process 2.

[0003] Prior art related to Process 1 includes static scale inhibition methods, such as the calcium carbonate precipitation method disclosed in GB / T 16632-2008, "Measurement of Scale Inhibition Performance of Water Treatment Agents," the bubbling method disclosed in HG / T 2024-2009, "Measurement of Scale Inhibition Performance of Water Treatment Agents," the limit carbonate method disclosed in HG / T 4541-2013, "Measurement of Scale Inhibition Performance of Water Treatment Agents," the turbidity method disclosed in V. Tantayakom et al., "Scale Inhibition Study by Turbidity Measurement," Journal of Colloid and Interface Science 284 (2005) 57-65, as well as the conductivity method, critical pH method, pH shift method, and dynamic simulation evaluation method. These methods all involve chemical or physical changes in a test solution with a certain degree of supersaturation, which indicate the amount of inorganic salts precipitated in the water or the critical point that occurs when precipitation begins. In the static scale inhibition and bubbling methods, the scale inhibition rate (precipitation inhibition rate) is calculated from the change in the concentration of scale-forming inorganic salt ions. In the limit carbonate method, the supersaturation level is continuously increased during the test while the concentrations of related ions are periodically measured. When a decrease in the concentration of scale-forming inorganic salt ions is measured, this is considered to be the critical point for the precipitation of inorganic salts in water. In the case of calcium carbonate scale, the sum of the total alkalinity and calcium ion concentration (both based on calcium carbonate) at this point is defined as the limit carbonate value. In the conductivity method, critical pH method, and turbidity method, the jump discontinuities of conductivity, pH, and turbidity are measured, and the supersaturation level at the jump discontinuity is calculated. This is then used to calculate the scale inhibition rate (precipitation inhibition rate), limit carbonate, critical supersaturation ratio, and critical supersaturation value.

[0004] Prior art related to Process 2 attempts to calculate the amount and rate of sparingly soluble salt precipitation by using the ratio of ions that are difficult to precipitate in water, such as potassium ions, sodium ions, and chloride ions, to precipitateable ions, as well as the mass balance of the water volume and ion concentrations in the water. Two fluorescent substances are added to water in a predetermined ratio, with one fluorescent substance synthesizing a scale inhibitor and the other fluorescent substance considered not to be consumed in the water. Monitoring the difference between the two fluorescent substances determines the consumption of the scale inhibitor. Furthermore, since the precipitation of sparingly soluble salts is considered to consume the scale inhibitor, the amount and rate of sparingly soluble salt precipitation are indirectly reflected. Hereinafter, this method is referred to as the 3D TRASAR™ method, heat exchanger monitoring method, etc. Theoretically, by measuring the change in the concentration of target inorganic ions in a water sample after a certain period of constant temperature, the precipitation rate of these inorganic substances in water can be calculated. In an actual use environment, the rate of deposition to be suppressed is very slow, and the accuracy and precision of the concentration analysis of these ions in the prior art is limited, so this method cannot be used to achieve the objective.

[0005] The capillary tube method, a type of dynamic simulation test method, reflects the degree of adsorption into the capillary tube after inorganic salt precipitation by measuring the change in pressure difference between the test solution in two sections of the capillary tube under constant temperature and pressure. This method requires strict control of the capillary flow rate, so a metering pump is used, which has very high accuracy but very low tolerance for suspended solids in the water. This limits its practical use in the field. Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a method for measuring the amount and rate of precipitation of sparingly soluble inorganic salts that change alkalinity when precipitated in water having inorganic carbon methyl orange alkalinity, which requires little manual intervention, has a low lower limit of quantification, and is highly accurate, as well as a measurement system, electronic device, and storage medium for the method. [Means for solving the problem]

[0007] To achieve the above objectives, the technical solution adopted in the present invention is to provide a method for measuring the precipitation rate of inorganic salts in water, which includes step S1: obtaining the type of precipitated inorganic salts in the sample water, one of the three inorganic carbon methyl orange alkalinity (Cmalk), pH, and total dissolved inorganic carbon (DIC), total dissolved solids (TDS), and the element and its content of the target inorganic salt that contributes to the non-inorganic carbon methyl orange alkalinity in the sample water; step S2: continuously measuring the time-dependent change in the carbon dioxide concentration (CO2w) in the sample water or the gas phase carbon dioxide concentration (PCO2) that is equilibrated with it in a sealed, constant temperature and pressure environment; step S3: obtaining the precipitation amount of the target inorganic salt based on the data obtained in step S1 and step S2; and step S4: obtaining the precipitation rate of the target inorganic salt based on the precipitation amount obtained in step S3 and the time of step S2.

[0008] Preferably, in step S1, the remaining two of the three inorganic carbon methyl orange alkalinity (Cmalk), pH, and total dissolved inorganic carbon (DIC) in the water are calculated according to the following formula: DIC = CO2w ​​× (1 + k'1 / (H + )+k'1×k'2 / (H + )^2 (1) Cmalk=50000×CO2w×(k'1 / (H + )+2k'1×k'2 / (H + )^2) (2) pH = -log(H + ) (3) In the formula, DIC is the total dissolved inorganic carbon concentration in water (mol / L), CO2w ​​is the carbon dioxide concentration in the measured water (mol / L), Cmalk is the inorganic carbon methyl orange alkalinity in water (mg / L, calcium carbonate standard), and H + is the hydrogen ion concentration (mol / L) in the water to be measured, k'1 is the first-order dissociation constant of carbonic acid, and k'2 is the second-order dissociation constant of carbonic acid.

[0009] Preferably, the target inorganic salt is calcium carbonate, and the water to be measured does not contain any other ions that contribute to non-inorganic carbon methyl orange alkalinity, and step S3 includes the following steps S311 to S313. In S311, Cmalk(t0) and CO2w(t0) at the time t0 are known, and H at the start time t0 is calculated according to the formulas (2) and (1). + (t0) and DIC(t0). In S312, CO2w(t1) at time t1 is known, and H at time t1 is calculated according to equation (5). + (t1), calculate Cmalk(t1) at time t1 according to equation (2), and calculate DIC(t1) at time t1 according to equation (4). (DIC(t0)-DIC(t1))×100×1000=(Cmalk(t0)-Cmalk(t1)) (4) 2×CO2w(t0)-2×CO2w(t1)=CO2w(t1)×k'1 / H + (t1)-CO2(t0)×k'1 / H + (t0) (5) In S313, the amount of precipitated calcium carbonate is calculated according to formula (6). CaCO3(s)(mg / L)=(DIC(t0)-DIC(t1))×10^5 (6)

[0010] Preferably, the precipitated inorganic salt is calcium phosphate, and the water to be measured has non-inorganic carbon methyl orange alkalinity contributed by orthophosphate, but does not contain any other ions contributing to non-inorganic carbon methyl orange alkalinity, and step S3 includes the following steps S321 to S323. In S321, Cmalk(t0) and CO2w(t0) at the time t0 are known, and H at the start time t0 is calculated according to Equation (2) and Equation (1). + (t0) and DIC(t0). In S322, CO2w(t1) at time t1 is known, and DIC(t1) and H +(t1) and calculate Cmalk(t1) at time t1 according to equation (2). DIC(t0)=DIC(t1)=CO2w(t1)×(1+k'1 / H + (t1)+k'1k'2 / (H + (t1)^2) (7) In S323, Tp(t0) at time t0 is known, DIP(t0) is found according to equation (9), Pmalk(t0) is calculated according to equations (10) to (12), DIP(t1) is calculated according to equations (8) to (12), and the amount of calcium phosphate precipitation is calculated according to equation (14). (DIP(t0)-DIP(t1)) / 2×2×50×1000=Cmalk(t0)+Pmalk(t0)-Cmalk(t1)-Pmalk(t1) (8) DIP=Tp / 95 / 1000 (9) Pmalk=(PO4 3- )×2×50000+(HPO4 2- )×1×50000 (10) (PO4 3- )=Tp / 95 / 1000×kp1×kp2×kp3 / ((H + )^3+(H + )^2×kp1+(H + )×kp1×kp2+kp1×kp2×kp3) (11) (HPO4 2- )=(PO4 3- )×(H + ) / kp3 (12) The amount of calcium phosphate precipitated is as follows: Ca3(PO4)2(s)=(DIP(t0)-DIP(t1)) / 2×310×1000 (14) where Pmalk is inorganic phosphorus methyl orange alkalinity (mg / L, calcium carbonate standard), DIP is total dissolved inorganic phosphorus concentration (mol / L), and Tp is total dissolved inorganic phosphorus concentration (mg / L, PO4 3- where kp1 is the first ionization constant of phosphoric acid, kp2 is the second ionization constant of phosphoric acid, and kp3 is the third ionization constant of phosphoric acid.

[0011] Preferably, the target inorganic salt is magnesium silicate, and the water to be measured has non-inorganic carbon methyl orange alkalinity contributed by silicate, but no other ions contribute to non-inorganic carbon methyl orange alkalinity, and step S3 includes the following steps S331 to S333. In S331, Cmalk(t0) and CO2(t0) at the time t0 are known, and H at the start time t0 is calculated according to the formulas (2) and (1). + (t0) and DIC(t0). In S332, CO2(t1) at time t1 is known, and DIC(t1) and H + (t1) and calculate Cmalk(t1) at time t1 according to equation (2). DIC(t0)=DIC(t1)=CO2(t1)×(1+k'1 / H + (t1)+k'1k'2 / (H + (t1)^2) (7) In S333, Tsi(t0) at time t0 is known, DISi(t0) is found according to equation (16), Simalk(t0) is calculated according to equations (17) and (18), DISi(t1) is calculated according to equations (15) to (18), and the amount of precipitated magnesium silicate is obtained according to equation (19). (DISi(t0)-DISi(t1))×2×50×1000=Cmalk(t0)+Simalk(t0)-Cmalk(t1)-Simalk(t1) (15) DISi=Tsi / 60 / 1000 (16) Sialk = 50000 × (Si(OH)O - ) (17) (Si(OH)O - )=DISi / (1+H + / Ksi) (18) The amount of magnesium silicate precipitated is as follows: MgSiO3(s)(mg / L)=(DISi(t0)-DISi(t1))×2×50×1000 (19) where DISi is the total dissolved inorganic silicon content (mol / L), Tsi is the total dissolved inorganic silicon content (mg / L, based on SiO2), Simalk is the inorganic silicon methyl orange alkalinity (mg / L, based on calcium carbonate), and Ksi is the dissociation constant of silicic acid.

[0012] Preferably, the target inorganic salt is colloidal silica, and the water to be measured has non-inorganic carbon methyl orange alkalinity contributed by silicate, but does not contain any other ions contributing to non-inorganic carbon methyl orange alkalinity, and step S3 includes the following steps S341 to S343. In S341, Cmalk(t0) and CO2(t0) at the time t0 are known, and H at the start time t0 is calculated according to the formulas (2) and (1). + (t0) and DIC(t0). In S342, CO2(t1) and Cmalk(t1) at time t1 are known, and DIC(t1) and H + (t1) and calculate Cmalk(t1) at time t1 according to equation (2). DIC(t0)=DIC(t1)=CO2(t1)×(1+k'1 / H + (t1)+k'1k'2 / (H + (t1)^2) (7) In S343, Tsi(t0) at time t0 is known, DISi(t0) is found according to equation (16), Simalk(t0) is calculated according to equations (17) and (18), DISi(t1) is calculated according to equations (16) to (18) and equation (20), and the amount of precipitated colloidal silica is calculated according to equation (21). (DIsi(t0)-DIsi(t1))×1×50×1000=-(Cmalk(t0)+Simalk(t0))+(Cmalk(t1)+Simalk(t1)) (20) DISi=Tsi / 60 / 1000 (16) Sialk = 50000 × (Si(OH)O - ) = 50000 × DISi / (1 + H + / Ksi) (17) (Si(OH)O - )=DISi / (1+H + / Ksi) (18) The amounts of precipitated colloidal silica are as follows: SiO2(s)(mg / L)=(DISi(t0)-DISi(t1)×1×60×1000 (21)

[0013] Preferably, step S2 includes measuring the carbon dioxide gas concentration PCO2 in a sealed measuring device, providing a gas circulation pump and a gas-phase carbon dioxide measuring device in a circuit of the sealed measuring device, continuously recording the carbon dioxide gas concentration PCO2 during measurement, and converting the carbon dioxide gas concentration PCO2 into the carbon dioxide concentration CO2w ​​in water according to Henry's law, CO2w ​​= Kh × PCO2, where Kh is the Henry's constant for carbon dioxide.

[0014] In order to achieve the above object, the present invention further provides an electronic device comprising a processor, a memory, and a computer program stored in the memory and operable on the processor, wherein the above method for measuring the precipitation rate of inorganic salts in water is realized when the processor executes the computer program.

[0015] To achieve the above object, the present invention further provides a computer-readable storage medium having a computer program stored therein, which, when executed by a processor, realizes the above method for measuring the precipitation rate of an inorganic salt in water.

[0016] In order to achieve the above object, the present invention further provides a system for measuring the precipitation rate of inorganic salts in water, comprising a sealed measuring device for measuring the concentration of carbon dioxide and the above-mentioned electronic device, wherein the electronic device further comprises an input / output module, and the output terminal of the sealed measuring device is signal-connected to the input / output module of the electronic device.

[0017] Furthermore, the sealed measuring device includes a test container, a carbon dioxide measuring device, a first constant temperature heating unit, and a gas circulation pump, and the water to be measured is placed in the test container, the inlet of the carbon dioxide measuring device is connected to the test container, and the outlet of the carbon dioxide measuring device is connected to the test container via the gas circulation pump, thereby forming a pipeline circuit through which carbon dioxide circulates, and the first constant temperature heating unit is placed in the test container and controls the temperature of the water to be measured to be constant. [Effects of the Invention]

[0018] The present invention has the following advantageous effects over the prior art. The present invention provides a method and system for measuring the precipitation rate of inorganic salts in water, as well as electronic devices and storage media. The method involves identifying the type of inorganic salt precipitated in an initial water quality analysis. The elements and their contents of the target inorganic salt that contribute to the inorganic carbon (Methyl Orange alkalinity), pH, and total dissolved inorganic carbon in the water are known. The method then calculates the precipitation rate of the target inorganic salt in water by measuring the time-dependent change in the carbon dioxide concentration in the water or the gas-phase carbon dioxide concentration that is in equilibrium with the water in a sealed, constant temperature and pressure environment. The measurement method provided by the present invention can be automatically processed and calculated using a computer program. This method improves the efficiency of method evaluation, significantly improves measurement accuracy, and reduces the amount of manual labor required when measuring the precipitation rate of a target inorganic salt in water in a laboratory and verifying precipitation rate adjustment methods. Similarly, by using the present invention for on-site measurement of the precipitation rate of a target inorganic salt in water and optimizing the precipitation rate adjustment method, a measurement system for the precipitation rate of an inorganic salt in water with a low lower limit of quantification, minimal human intervention, and a short measurement time is provided, providing an excellent tool for on-site automatic optimization and adjustment of the inorganic salt precipitation rate. The present invention has great potential in the intelligentization of water treatment, and its applicable fields include, but are not limited to, circulating cooling water, surface water, geothermal water, and drinking water, concentrates from reverse osmosis water systems, concentrates from solar seawater desalination, water prone to the deposition of colloidal silica and magnesium silicate, measurement and adjustment of scale formation in vacuum salt-making processes for brine, and measurement and adjustment of scale formation in related water systems in oil and natural gas extraction. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a flow chart of measuring the precipitation rate of inorganic salts in water provided by an embodiment of the present invention. [Figure 2] 1 is a schematic diagram of the structure of a carbon dioxide concentration measuring device provided by an embodiment of the present invention; [Figure 3]1 is a block diagram of the principle of a system for measuring the precipitation rate of an inorganic salt in water provided by an embodiment of the present invention. [Figure 4a] FIG. 1 is a statistical diagram showing the change in PCO2 over time in the measurement of the precipitation rate of calcium carbonate according to an embodiment. [Figure 4b] FIG. 1 is a statistical diagram showing the change in PCO2 over time in the measurement of the precipitation rate of calcium carbonate according to an embodiment. [Figure 5] FIG. 1 is a schematic diagram comparing the precipitation rate of calcium carbonate calculated by an example of the present invention and a conventional alkalinity titration method. [Figure 6a] PCO2 records at different test temperatures for field water and field water with added scale inhibitor. [Figure 6b] Linear regression of PCO2 measured at 25°C during the last 30 minutes. [Figure 6c] Linear regression of PCO2 for the last 30 minutes at 55°C and 75°C. [Figure 7] This is a statistical graph of the results of calculations using the precipitation rate of Type 1 calcium carbonate for on-site water. DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention will now be further described with reference to the following figures and examples.

[0021] FIG. 1 is a flow chart of the measurement of the precipitation rate of an inorganic salt in water provided by an embodiment of the present invention.

[0022] Referring to FIG. 1, the method for measuring the precipitation rate of an inorganic salt in water provided by this embodiment includes the following steps S1 to S4. In S1, the type of precipitated inorganic salt in the water being measured, one of the three inorganic carbon methyl orange alkalinity (Cmalk), pH, and total dissolved inorganic carbon (DIC) in the water being measured, the total dissolved solids content of the water being measured (which can be converted using the water conductivity), and the elements and their contents of the target inorganic salts that contribute to the non-inorganic carbon methyl orange alkalinity are obtained. Water alkalinity refers to the total amount of substances in water that can quantitatively react with a strong acid. Methyl orange alkalinity is the total amount of substances in water that are consumed by a strong acid when it quantitatively neutralizes the water until the methyl orange indicator changes color from saffron to orange (the pH of the solution changes from 4.4 to 4.5) (120). The source of methyl orange alkalinity in water varies depending on the water quality.

[0023] Water with inorganic carbon methyl orange alkalinity refers to water that contains carbon dioxide, bicarbonate ions, and carbonate ions. In water with inorganic carbon methyl orange alkalinity, the three forms of inorganic carbon present and the hydrogen ion concentration (H + There is advanced research and quantitative relationship between inorganic carbon and methyl orange alkalinity (Cmalk). A brief description is given below. DIC = CO2w ​​× (1 + k'1 / (H + )+k'1×k'2 / (H + )^2 (1) Cmalk=50000×CO2w×(k'1 / (H + )+2×k'1×k'2 / (H + )^2) (2) pH = -log(H + ) (3) In the formula, CO2w ​​is the carbon dioxide concentration in the water being measured, and H + is the hydrogen ion concentration in the water being measured, and its negative logarithm is the pH of the solution. k'1 is the first-order dissociation constant of carbonic acid after correction for temperature and the ionic strength of the water. k'2 is the second-order dissociation constant of carbonic acid after correction for temperature and the ionic strength of the water. k'1 and k'2 can be selected or calculated from existing data and materials based on the water quality characteristics, temperature, and solids content of the water being measured. As can be seen from equations (1), (2), and (3), any two of the four parameters (DIC, Cmalk, pH, and CO2w) can be determined by knowing the remaining two. In a sealed measurement system with constant temperature and pressure, if one of the three parameters (initial DIC, Cmalk, and pH) of the water is known, measuring CO2w ​​allows the unknown two parameters to be calculated.

[0024] Under certain conditions, different types of inorganic salts precipitate and dissolve in water. There is a wealth of knowledge and calculation software available to determine and calculate the types and thermodynamic trends of deposits that may occur in target water. In this invention, inorganic salts are divided into three types based on whether they change the total methyl orange alkalinity (Tmalk) and total dissolved inorganic carbon (DIC) in water after precipitation. Type 1 changes both, Type 2 changes only Tmalk, and Type 3 does not change either. Table 1 lists the classification results of common inorganic scales based on this classification rule and the quantitative change relationships of water components after precipitation. As can be seen from Table 1, calcium carbonate reduces the Cmalk and DIC of water after precipitation, but does not change the total dissolved inorganic phosphorus (DIP) or total dissolved inorganic silicon (DISi). Calcium sulfate does not change Tmalk, DIC, DIP, or DISi after precipitation. After precipitation, calcium phosphate reduces the water's Pmalk and DIP but does not change the DIC. After precipitation, magnesium silicate reduces the water's Smalk but does not change the DIC. Colloidal silica is a polymer of silicic acid, and each polymerization of a silicic acid molecule produces one hydroxide ion, improving the water's alkalinity but not its DIC. In short, when Type 1 or Type 2 scale forms in water, Tmalk changes, altering the carbonate equilibrium and changing the pH and CO2w. Based on the change in CO2w, the amount of precipitation of Type 1 or Type 2 scale can be combined with the quantitative relationships between Tmalk, DIC, DIP, and DIsi to calculate the amount of the corresponding inorganic salts precipitated. [Table 1]

[0025] In S2, the change over time in the carbon dioxide concentration CO2w ​​in the measurement water or the gas-phase carbon dioxide concentration PCO2 that is in equilibrium with CO2w ​​is measured in a sealed, constant temperature and pressure environment. When measuring the concentration of carbon dioxide, the concentration CO2w ​​in water may be measured directly, or the concentration PCO2 in the gas phase space where it is in equilibrium with water may be measured, and the carbon dioxide concentration CO2w ​​in water may be calculated using the Henry's constant Kh of carbon dioxide, i.e., PCO2 x Kh.

[0026] Referring to FIG. 2, in one specific example, a sealed measuring device with a total volume of 500 mL and capable of constant temperature heating and cooling was constructed to measure the gas-phase carbon dioxide concentration in equilibrium with the water being measured 8. A gas circulation pump 6 and a carbon dioxide measuring device 4 were installed in the circuit of the sealed measuring device. The gas-phase carbon dioxide concentration was continuously recorded during the measurement. Specifically, the sealed measuring device includes a test container 1, a carbon dioxide measuring device 4, a first constant temperature heating unit 3, and a gas circulation pump 6. The water being measured 8 is installed in the test container 1. The inlet of the carbon dioxide measuring device 4 is connected to the test container 1, and the outlet of the carbon dioxide measuring device 4 is connected to the test container 1 via the gas circulation pump 6, forming a pipeline circuit through which carbon dioxide circulates. A first constant temperature heating unit 9 is installed in the test container 1 and controls the temperature of the water being measured to be constant.

[0027] In a specific embodiment, the test container 1 may be a test cup having a diameter of 65 mm and a height of 150 mm, with a polytetrafluoroethylene coating on the inside, the test cup being provided with a test cup water inlet valve 14 and a test cup water outlet valve 16, and having a jacket 11, the jacket 11 being arranged to wrap around the outside of the test container 1, an insulating layer 12 being provided on the outside of the jacket 11, and the jacket 11 being provided with a jacket water inlet valve 13 and a jacket water outlet valve 15. A connection hole 17 is opened in the top cover of the test vessel 1, and a pipeline 10 is connected to the connection hole 17. In this embodiment, the pipeline 10 is a 304 stainless steel pipe with an outer diameter of 16 mm and an inner diameter of 9 mm. A gas constant temperature cooling unit 2 and a second constant temperature heating unit 3 are installed in this order outside the pipeline between the test vessel 1 and the carbon dioxide measuring instrument 4. The gas constant temperature cooling unit 2 includes a first temperature sensor 21, a cooling plate 22, and a first controller 23. The cooling plate 22 is installed to surround the outside of the pipeline, and the cooling surface of the cooling plate 22 is made of metal. The stainless steel outer tube is closely connected to the tin metal through the tin metal. A first temperature sensor 21 is located between the cooling plate 22 and the pipe, i.e., the first temperature sensor 21 is located between the tin metal and the stainless steel outer tube. A first controller 23 (PID control) is electrically connected to the first temperature sensor 21 and the cooling plate 22 to control the temperature inside the tin metal and the stainless steel tube to a first predetermined value, which may be 5±0.5°C. In this embodiment, the stainless steel tube in this cooling section is 40 mm long. The second constant-temperature heating unit 3 includes a heating wire 32, a second temperature sensor 31, and a second controller 33. The heating wire 32 is wrapped around the outside of the stainless steel tube. In this embodiment, the heating wire 32 is a polytetrafluoroethylene low-voltage heating wire with an outer diameter of 1.2 mm and a resistance of 10 Ω / m, two of which are wound in parallel for 20 turns, forming a heating section in the stainless steel tube with a total length of 48 mm. The second temperature sensor 31 is disposed between the wall of the stainless steel outer tube and the heating wire 32, and the second controller 33 (PID control) is electrically connected to the heating wire 32 and the second temperature sensor 31, and controls the pipe temperature to be at a second predetermined value, which is greater than the first predetermined value.In this embodiment, the second controller 33 controls the temperature of the stainless steel outer tube wall to 55±0.5°C. The gas constant temperature cooling unit 2 and second constant temperature heating unit 3 are provided to meet the humidity requirements for the measured gas of the carbon dioxide sensor 41 (SenseAir S8 / 004-0-0053, manufactured by SenseAir, Sweden) selected for this test. The gas constant temperature cooling unit 2 and second constant temperature heating unit 3 are provided to cool and then heat the measured gas, thereby achieving the goal of reducing the humidity of the measured gas. In other embodiments, a carbon dioxide sensor 41 with high humidity adaptability may be selected, and the gas constant temperature cooling unit 2 and second constant temperature heating unit 3 may be omitted.

[0028] After the humidity of the gas to be measured is reduced by the gas constant temperature cooling unit 2 and the second constant temperature heating unit 3, the gas enters the carbon dioxide measuring device 4. The carbon dioxide measuring device 4 includes a measuring chamber 41, a carbon dioxide sensor 42, and a display converter 43. In this embodiment, the measuring chamber 41 is a 316 stainless steel cylinder with an inner diameter of 25 mm and a height of 45 mm. The bottom of the measuring chamber 41 is connected to the top of the conduit 10, and the top of the measuring chamber 41 is connected to the gas-phase pressure balance bag 5 via a 3 mm diameter 316 stainless steel capillary tube. The measuring chamber 41 contains a carbon dioxide sensor 42, which is connected to the display converter 43, which measures and records the carbon dioxide concentration once per minute. The gas-phase pressure balance bag 5 is an aluminum foil airbag with a length and width of 100 mm and a width of 80 mm, respectively, coated on the inside with a polytetrafluoroethylene film. One of the two ports of the gas-phase pressure balance bag 5 is connected to the measurement chamber 41, and the other is connected to a capillary tube and then to a gas circulation pump 6. The outlet of the gas circulation pump 6 is connected to the test vessel 1 via a 3 mm diameter 316 capillary tube. A gas distributor 7 introduces gas into the test water at a circulating flow rate of 60 ± 20 mL / min. The first constant-temperature heating unit 9 heats and keeps the test water warm. It includes a heater 91, a third temperature sensor 92, and a third controller 93. The heater 91 is located on the outside of the bottom of the test vessel 1, and the third temperature sensor 92 is located inside the test vessel 1. The third controller 93 is electrically connected to the third temperature sensor 92 and the heater 91, respectively, and controls the temperature of the test water 8 to a third predetermined temperature. When the test temperature is higher than 25°C, the first constant-temperature unit 9 is used to heat and keep the test water warm. When the test temperature is equal to or less than 25°C, the temperature of the water to be measured is maintained by external constant-temperature water via the test cup jacket 11. Measurements showed that the total capacity of the test system was 500 mL at 25°C. Statistics of the initial measurement data controlled by the system temperature showed that the temperature of the water to be measured could be stabilized at the set value within 20 to 25 minutes after the test started.The temperature deviation during constant temperature was ±0.5°C.

[0029] In S3, a target amount of precipitated inorganic salt is obtained based on the data acquired in steps S1 and S2. In the first embodiment, the target inorganic salt is calcium carbonate, and the water to be measured does not contain any other ions that contribute to non-inorganic carbon methyl orange alkalinity, and specifically, the method includes steps S311 to S313. In S311, Cmalk(t0) and CO2w(t0) at the time t0 are known, and H at the start time t0 is calculated according to the formulas (2) and (1). + (t0) and DIC(t0). In S312, H by S311 + (t0) and DIC(t0) are obtained, CO2w(t1) at time t1 is known, and H at time t1 is calculated according to equation (5). + (t1) is calculated, then DIC(t1) is calculated according to equation (1), and Cmalk(t1) is calculated according to equation (2). The process for deriving equation (5) is as follows: The precipitation of calcium carbonate reduces the total dissolved inorganic carbon in the water, and its methyl orange alkalinity reduces the inorganic carbon methyl orange alkalinity in the water, and both values ​​are equal. The left side of equation (4) represents the methyl orange alkalinity content of the precipitated calcium carbonate, and the right side of equation (4) represents the change in inorganic carbon methyl orange alkalinity in the water, and both are equal. Equation (5) can be derived from equation (4). (DIC (t0) -DIC (t1) )×100×1000=(Cmalk (t0) -Cmalk (t1) ) (4) ↓ 10^5×DIC (t0) -10^5×DIC (t1) =Cmalk (t0) -Cmalk (t1) ↓ 10^5×CO2w(t0)×(1+k'1 / H + (t0)+k'1k'2 / (H + (t0) )^2-10^5×CO2w(t1)×(1+k'1 / H + (t1) +k'1k'2 / (H + (t1) )^2=CO 2(t0) ×(50000×k'1 / (H + (t0) +100000×k'1k'2 / (H + (t0) ^2)-CO 2(t1) ×(50000×k'1 / (H + (t1) +100000×k'1k'2 / (H + (t1) ^2) ↓ 2×CO2w(t0)-2×CO2w(t1)=CO2w(t1)×k'1 / H + (t1)-CO2w(t0)×k'1 / H + (t0) (5) In S313, the amount of precipitated calcium carbonate is calculated according to formula (6). CaCO3(s)(mg / L)=(DIC(t0)-DIC(t1))×10^5 (6)

[0030] In the second embodiment, the target inorganic salt is calcium phosphate, and the water to be measured contains no other ions that contribute to the non-inorganic carbon methyl orange alkalinity except for the non-inorganic carbon methyl orange alkalinity contributed by orthophosphate, and specifically includes the following steps S321 to S323. In S321, Cmalk(t0) and CO2w(t0) at the time t0 are known, and H at the start time t0 is calculated according to Equation (2) and Equation (1). + (t0) and DIC(t0). In S322, CO2w(t1) and Cmalk(t1) at time t1 are known, and DIC(t1) and H + Calculate (t1). DIC(t0)=DIC(t1)=CO2w(t1)×(1+k'1 / H +(t1)+k'1k'2 / (H + (t1)^2) (7) The precipitation of non-carbonates does not change the DIC, and according to Eq. (7), H + Find (t1). In S323, Tp(t0) at time t0 is known, DIP(t0) is calculated according to equation (9), and equation (13) can be derived according to equations (10) to (12). Next, Pmalk(t0) is calculated according to equation (13), DIP(t1) and Pmalk(t1) are calculated according to equations (8) and (13), and the amount of calcium phosphate precipitation is calculated according to equation (14). (DIP(t0)-DIP(t1)) / 2×2×50×1000=Cmalk(t0)+Pmalk(t0)-Cmalk(t1)-Pmalk(t1) (8) DIP=Tp / 95 / 1000 (9) Pmalk=(PO4 3- )×2×50000+(HPO4 2- )×1×50000 (10) (PO4 3- )=DIP×kp1×kp2×kp3 / ((H + )^3+(H + )^2×kp1+(H + )×kp1×kp2+kp1×kp2×kp3) (11) (HPO4 2- )=(PO4 3- )×(H + ) / kp3 (12) Pmalk=(DIP×kp1×kp2×kp3 / ((H + )^3+(H + )^2×kp1+(H + )×kp1×kp2+kp1×kp2×kp3))×2×50000+(DIP×kp1×kp2×kp3 / ((H + )^3+(H + )^2×kp1+(H + )×kp1×kp2+kp1×kp2×kp3))×(H + ) / kp3×1×50000 (13) The amount of calcium phosphate precipitated is as follows: Ca3(PO4)2(s)=(DIP(t0)-DIP(t1)) / 2×310×1000 (14) where Pmalk is inorganic phosphorus methyl orange alkalinity (mg / L, based on calcium carbonate), DIP is total dissolved inorganic phosphorus (mol / L), and Tp is total dissolved inorganic phosphorus content (mg / L, PO4 3- where kp1 is the first ionization constant of phosphoric acid, kp2 is the second ionization constant of phosphoric acid, and kp3 is the third ionization constant of phosphoric acid.

[0031] After calcium phosphate precipitates, the total dissolved inorganic phosphorus (DIP) in the water and the methyl orange alkalinity (non-inorganic carbon methyl orange alkalinity) contributed by phosphate ions are reduced, and the left side of equation (8) is the methyl orange alkalinity represented by the precipitated calcium phosphate, and the right side is the reduction in methyl orange alkalinity shown in the water, and both should be equal.

[0032] CO2w(t0) = PCO2t0 × Kh and CMalk(t0) are known values, and according to equation (2), H + (t0) can be calculated, and then DIC(t0) can be calculated according to equation (1). Calcium phosphate does not contain carbonate, and after it is precipitated from water, it does not change the DIC in the water, i.e., DIC(t1) = DIC(t0). Therefore, according to equation (7), H + (t1) can be calculated, and then Cmalk(t1) is calculated according to equation (2). As a result, only DIP(t1) and Pmalk(t1) remain unknown in equation (8), and since DIP(t1) and Pmalk(t1) must satisfy equation (13), DIP(t1) and Pmalk(t1) can be solved using equations (8) and (13). One solution is a trial-and-error method for DIP(t1), where different values ​​of DIP(t1) are set to calculate DIP(t1) and Pmalk(t1) that satisfy equations (8) and (13), and then the amount of calcium phosphate precipitation is calculated according to equation (14).

[0033] In the third embodiment, the target inorganic salt is magnesium silicate, and the water to be measured contains no other ions that contribute to the non-inorganic carbon methyl orange alkalinity except for the non-inorganic carbon methyl orange alkalinity contributed by silicate, and specifically, the method includes the following steps S331 to S333. In S331, Cmalk(t0) and CO2w(t0) at the time t0 are known, and H at the start time t0 is calculated according to Equation (2) and Equation (1). + (t0) and DIC(t0). In S332, CO2w(t1) and Cmalk(t1) at time t1 are known, and DIC(t1) and H + Calculate (t1). DIC(t0)=DIC(t1)=CO2w(t1)×(1+k'1 / H + (t1)+k'1k'2 / (H + (t1)^2) (7) In S333, Tsi(t0) at time t0 is known, DISi(t0) is found according to equation (16), Simalk(t0) is calculated according to equations (17) and (18), DISi(t1) is calculated according to equations (15) to (18), and the amount of precipitated magnesium silicate is obtained according to equation (19). (DISi(t0)-DISi(t1))×2×50×1000=Cmalk(t0)+Simalk(t0)-Cmalk(t1)-Simalk(t1) (15) DISi=Tsi / 60 / 1000 (16) Sialk = 50000 × (Si(OH)O - ) (17) (Si(OH)O - )=DISi / (1+H + / Ksi) (18) The amount of magnesium silicate precipitated is as follows: MgSiO3(s)(mg / L)=(DISi(t0)-DISi(t1))×2×50×1000 (19) where DISi is total dissolved inorganic silicon (mol / L), Tsi is the total dissolved silicon content on an SiO2 basis in mg / L, Simalk is inorganic silicon methyl orange alkalinity (mg / L, on a calcium carbonate basis), and Ksi is the dissociation constant of silicic acid.

[0034] After magnesium silicate precipitates, the alkalinity in the water is reduced, and the left side of equation (15) is the methyl orange alkalinity in terms of precipitated magnesium silicate, and the right side is the reduction in alkalinity shown in the water, and both should be equal.

[0035] CMalk(t0) and CO2w(t0) = PCO2(t0) × Kh are known values, and according to equation (2), H + (t0) can be calculated, and then DIC(t0) can be calculated according to equation (1). The precipitation of magnesium silicate from the water reduces the methyl orange alkalinity of the water and causes a decrease in pH. Since non-carbonate alkalinity does not contain inorganic carbon, the DIC of the water remains unchanged. According to equation (7), H + (t1) can be calculated, and then Cmalk(t1) can be calculated. From the molecular formula of magnesium silicate, it can be seen that when 1 mol / L of magnesium silicate precipitates, the total dissolved silicon is reduced by 1 mol / L and at the same time the alkalinity based on calcium carbonate is reduced by 2 x 50 x 1000 mg / L, i.e., (DISi(t0) - DISi(t1)) x 2 x 50 x 1000 = Talk(t0) - Talk(t1). The total dissolved inorganic silicon concentration Tsi(t0) at t0 is known, and H at t0 can be calculated. + (t0) is known, and based on the dissociation constant of silicic acid, the alkalinity Simalk(t0) contributed by silicon at t0 can be calculated. After setting one value of DISi(t1), H +Simalk(t1) can be calculated from DISi(t1) and the dissociation constant of silicic acid. Therefore, by performing trial and error calculations on DISi(t1), it is possible to find DISi(t1) that satisfies equation (15), and then calculate the amount of precipitated magnesium silicate according to equation (19).

[0036] In the fourth embodiment, the target inorganic salt is colloidal silica, and the water to be measured contains no other ions that contribute to the non-inorganic carbon methyl orange alkalinity other than the non-inorganic carbon methyl orange alkalinity contributed by silicate, and specifically, the method includes the following steps S341 to S343. In S341, Cmalk(t0) and CO2w(t0) at the time t0 are known, and H at the start time t0 is calculated according to Equation (2) and Equation (1). + (t0) and DIC(t0). In S342, CO2w(t1) and Cmalk(t1) at time t1 are known, and DIC(t1) and H + (t1) and calculate Cmalk(t1) at time t1 according to equation (2). DIC(t0)=DIC(t1)=CO2w(t1)×(1+k'1 / H + (t1)+k'1k'2 / (H + (t1)^2) (7) In S343, Tsi(t0) at time t0 is known, DISi(t0) is found according to equation (16), Simalk(t0) is calculated according to equations (17) and (18), DISi(t1) is calculated according to equations (16) to (18) and equation (20), and the amount of precipitated colloidal silica is calculated according to equation (21). (DIsi(t0)-DIsi(t1))×1×50×1000=-(Cmalk(t0)+Simalk(t0))+(Cmalk(t1)+Simalk(t1)) (20) DISi=Tsi / 60 / 1000 (16) Sialk = 50000 × (Si(OH)O - ) = 50000 × DISi / (1 + H + / Ksi) (17) (Si(OH)O - )=DISi / (1+H + / Ksi) (18) The amounts of precipitated colloidal silica are as follows: SiO2(s)(mg / L)=(DISi(t0)-DISi(t1)×1×60×1000 (21)

[0037] Cmalk(t0) and CO2w(t0) = PCO2(t0) × Kh are known values, and according to equation (2), H + (t0) can be calculated, and then DIC(t0) can be calculated according to equation (1). Since colloidal silica does not contain inorganic carbon, the DIC of water does not change. According to equation (7), H + (t1) can be found, and then Cmalk(t1) can be found.

[0038] Colloidal silica is the self-polymerization of orthosilicic acid, and each polymerization of orthosilicic acid produces one hydroxide ion in water, increasing the alkalinity of the water. The left side of equation (20) is a quantitative description of how precipitated colloidal silica reduces total dissolved inorganic silicon (DISi, mol / L) while simultaneously increasing the alkalinity of the water, and the right side is the increase in alkalinity shown in the water; both must be equal.

[0039] The total dissolved inorganic silicon concentration Tsi at time t0 is known, and DISi(t0) can be calculated using Equation 16. Then, the H + Based on the dissociation constant of the bond (t0), the alkalinity Simalk(t0) contributed by silicon at t0 is calculated. As a result, in equation (20), DISi(t1) and Simalk(t1) are unknown. DISi(t1) and Simalk(t1) satisfy equation (17), and H +Since (t1) is a known value, DISi(t1) and Simalk(t1) can be solved according to equations (20) and (17). One solution is a trial-and-error method for DISi(t1), and once DISi(t1) that satisfies equations (20) and (17) is found, the amount of colloidal silica precipitated is then calculated according to equation (21).

[0040] In step S4, a target inorganic salt deposition rate is obtained based on the deposition amount obtained in step S3.

[0041] Dividing the deposition amount by the time it took to form (t1-t0) gives the average deposition rate within the test period.

[0042] This embodiment further provides an electronic device including a processor, a memory, and a computer program stored in the memory and operable on the processor, wherein the above-described method for measuring the precipitation rate of a target inorganic salt is realized when the processor executes the computer program.

[0043] This embodiment further provides a computer-readable storage medium having a computer program stored therein, which, when executed by a processor, realizes the above-described method for measuring the precipitation rate of a target inorganic salt.

[0044] Example 1 In this example, the precipitation rate of calcium carbonate is calculated from the measurement results of the gas phase carbon dioxide concentration PCO2 using calculation software provided by the present invention.

[0045] Initial water quality analysis and scale formation tendency assessment revealed that the test water had a tendency to precipitate calcium carbonate and contained no other ions that contribute to non-inorganic carbon methyl orange alkalinity. The water's Cmalk was known to be 320 mg / L and its TDS was 1118 mg / L. 470 mL of test water was added to the test device, the test water temperature was set to 25°C, the test device was started, and PCO2 was continuously measured and recorded. After one hour, the test was completed. From the PCO2 recorded during the test, it was found that PCO2 = 994 ppmv 30 minutes after the test and PCO2 = 1099 ppmv 60 minutes after the test. Table 2 lists the specific steps for calculating the amount of calcium carbonate precipitate using the calculation software provided by the present invention. Dividing the precipitate amount calculated in Table 2 by the time the precipitate formed, the average precipitation rate during the test period was 1.8 / 0.5 = 3.6 mg / L / h. [Table 2] JPEG2026502224000004.jpg229152

[0046] Further below, a specific use of the present invention for measuring the characteristics of a crystallization reaction of a target inorganic salt (Process 1) in the laboratory is described.

[0047] Example 2 This example is a calcium carbonate crystal precipitation test.

[0048] The characteristics of the crystallization reaction, which is the precipitation of a target inorganic salt in water, are evaluated in the laboratory. One conventional method is the static scale inhibition method, in which two stock solutions are prepared, mixed, and placed in a specific test environment, causing the target inorganic salt to crystallize. The precipitation characteristics of the target inorganic salt are quantitatively evaluated by analyzing the concentration of the target ion before and after the test. In this test, the carbon dioxide concentration measurement device and calculation method of the present invention were used to obtain the calcium carbonate precipitation rate. At the same time, the total methyl orange alkalinity of the water before and after the test was analyzed, obtaining a series of data similar to that of a conventional static scale inhibition test. Furthermore, the amount and deposition rate of calcium carbonate precipitation were calculated using this data, and the two sets of data were compared.

[0049] 1. Exam Preparation 1) Preparation of 0.5 mg (active) ATMP / mL stock solution 0.25 g of 50% ATMP (a common scale inhibitor, nitrilotris (methylene phosphonic acid), purchased from Taobaowan, a leading supplier of scale inhibitors) was weighed out and placed in a 200 mL beaker. Approximately 100 mL of deionized water was added, mixed evenly, and the pH was adjusted to 7.0 ± 0.1 with 0.1 N NaOH. The volume was then adjusted to 250 mL with deionized water.

[0050] 2) Preparation of stock solutions A and B Prepare stock solution A. 1.813 g of NaHCO3 (analytical grade, China National Medicines Corporation Ltd.) was weighed into a 200 mL beaker and dissolved in approximately 100 mL of deionized water. This was then added to a 2 L volumetric flask. 0.127 g of Na2CO3 (analytical grade, China National Medicines Corporation Ltd.) was weighed into a 200 mL beaker and dissolved in 100 mL of deionized water. This was then added to the 2 L volumetric flask. The 200 mL beaker was then rinsed two or three times with deionized water, and the rinses were added to the 2 L volumetric flask. This preparation of stock solution A was repeated once. The two preparations were mixed and placed in a 5 L glass bottle, tightly capped, and ready for use.

[0051] Prepare stock solution B. Weigh out 1.763 g of CaCl2·2H2O (analytical grade, Fuchen (Tianjin) Chemical Reagent Co., Ltd.) into a 200 mL beaker and dissolve it in approximately 100 mL of deionized water. Add the solution to a 2 L volumetric flask. Rinse the 200 mL beaker two or three times with deionized water, add the rinse solution to the 2 L volumetric flask, and then add deionized water to the final volume. Repeat the preparation of stock solution B. Mix the two preparations and place in a 5 L glass bottle. Secure the cap tightly for use.

[0052] 3) Initial methyl orange alkalinity titration was performed. 250 mL of stock solution A was taken in a measuring flask, and 250 mL of deionized water was taken in another measuring flask. The two liquids were mixed and stored in a 500 mL glass bottle with a cap. The sample was filtered through a 0.45 μm membrane filter (Aqueous MCE 25 mm, De-Flor Technology). A 50 mL sample was pipetted into a 200 mL Erlenmeyer flask, and 3-5 drops of 0.1% methyl orange indicator were added. The sample was then titrated with 0.05 N HCl standard solution (provided by Taobao Wan Laboratory Standard Reagents). Each sample was repeated three times, and the mean and standard deviation were calculated.

[0053] 2. Calcium carbonate crystal precipitation test 250 mL of stock solution A was taken from a 250 mL volumetric flask and placed in a 1000 mL beaker. Different amounts of ATMP stock solution were added as designed. Another 250 mL of stock solution B was taken from a 250 mL volumetric flask and placed in the 1000 mL beaker containing stock solution A. The mixture was then homogenized using a glass rod. The calculated water quality for the two stock solutions, calculated in equal parts, is shown in Table 3. Using the relevant calculation software, the calcite supersaturation index of the test solution was determined to be 1.68 at 25°C. 470 g of test solution was taken and placed in the test apparatus. The test temperature was set to a constant 25°C, and the test time was 1 hour. PCO2 was continuously recorded during the test, and a time-course curve was plotted after the test was completed. After 1 hour, the test solution was filtered through a 0.45 μm membrane filter, and a sample was taken with a 50 mL pipette and added to a 200 mL Erlenmeyer flask. After adding 3 to 4 drops of methyl orange indicator, the solution was titrated with 0.05 N HCl. The measurement was repeated three times, and the average and standard deviation were calculated. [Table 3]

[0054] 3. Test Results Table 4 shows the test configuration and test result statistics. Figures 4a and 4b show statistical graphs of the change in PCO2 over time.

[0055] The initial measurement of the thermostatic characteristics of the test equipment revealed that the water temperature remained constant at 25±0.5°C approximately 20 to 25 minutes after the start of the test. Therefore, as shown in Figure 5, the slope and intercept were determined by linear regression for the data from 30 to 60 minutes of the test, and the PCO2 values ​​at 0 and 60 minutes were calculated using these slopes and intercepts. Subsequently, the amount and rate of calcium carbonate precipitation were calculated using these values. The final calculation results are summarized in Table 4. [Table 4] JPEG2026502224000007.jpg229118JPEG2026502224000008.jpg22980

[0056] FIG. 5 shows a schematic comparison of calcium carbonate deposition rates calculated by the present invention and the conventional alkalinity titration method.

[0057] The following was found in this test: 1) In the case of CaCO3 standard, the absolute error of alkalinity titration is about 5 mg / L, that is, the resolution of calcium carbonate deposition rate calculated by alkalinity method is less than 5 mg / L / h.

[0058] 2) Data from two repeats of the method of the present invention at 25bbp, 75bbp, and 100 ppb showed that the resolution of the method of the present invention was 2 mg / L / h.

[0059] 3) At an addition amount of 0 ppb ATMP, there was a large difference of about 5 mg / L / h between the measurement results of the two methods. The reason for this is thought to be as follows: The sample to which no scale inhibitor was added maintained a high deposition rate even after 1 hour. Since it took about 15 minutes to collect and filter the sample and about 5 minutes each time the alkalinity was measured, the data measured by the alkalinity method was actually 25 / 1.5 = 17 mg / L / h, which corresponds to about 1.5 hours, and is close to the result measured by the method of the present invention.

[0060] 4) The present invention does not require laborious alkalinity titration, requires less work, allows continuous data measurement, and is highly reliable because there is no human intervention.

[0061] Example 3 A specific example of use of Process 2 (measurement of crystallization reaction characteristics of inorganic salts during on-site use) of the present invention will be described below.

[0062] A facility uses circulating cooling water, tap water for supplemental water, and phosphorus-free circulating water corrosion and scale inhibition treatment. During actual use on-site, it was discovered that scale formation was not being properly controlled in some high-temperature heat exchangers, so the scale and corrosion inhibitor treatment is planned to be adjusted. The results of the water quality analysis on-site are shown in Table 5. Based on the water quality and the source of the supplemental water, it was determined that the main scale-forming inorganic salt in the circulating water was calcium carbonate.

[0063] Circulating water from the site was collected and, using the method of the present invention, the precipitation rate of calcium carbonate, a type 1 inorganic precipitate, was calculated for the site water and the site water supplemented with scale inhibitor at temperatures of 25°C, 55°C, and 75°C. Table 5 shows the test configuration and results. Figure 6a shows the PCO2 records for the site water and the site water supplemented with scale inhibitor at different test temperatures. Figure 6b shows the linear regression of PCO2 measured over the last 30 minutes at 25°C, and Figure 6c shows the linear regression of PCO2 measured over the last 30 minutes at 55°C and 75°C. Figure 7 shows the statistics of the calculated precipitation rate of calcium carbonate, type 1, for the site water. Figure 7 shows that the precipitation rate of calcium carbonate for the site water at 25°C and 55°C was less than 0.9 mg / L / h. However, when the temperature was increased to 75°C, the calcium carbonate-based deposition rate of the on-site water without scale inhibitor addition rapidly increased to 6.7 mg / L / h, while that of the on-site water with scale inhibitor addition remained at 0.6 mg / L / h, approximately the same level as that without scale inhibitor addition at 55°C. This indicates that for high-temperature heat exchangers, traditional on-site chemical treatment methods need to be adjusted. One method is to increase the concentration of scale inhibitors, but given the cost of reagents, other methods, such as reducing pH, can also be adopted. After adjusting the on-site treatment method, water can be sampled again and the inorganic salt deposition rate measured using the method of the present invention until the optimal method for inhibiting inorganic salt deposition is found. [Table 5]

[0064] As can be seen from the above test, the present invention was able to obtain the above data in just 6 hours, and all calculation procedures were performed by the program; the only things that needed to be manually input were the initial Cmalk (or pH, or DIC) and TDS (which can be converted into conductivity). There is no need to frequently perform complex alkalinity or calcium ion analyses.

[0065] Although the present invention has been disclosed above in the preferred embodiments, the present invention is not limited thereto. It is obvious that those skilled in the art may make some modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention is governed by the content defined in the claims. [Explanation of symbols]

[0066] 1 test container 10 conduit 11 Jacket 12 Thermal layer 13 Jacket water supply valve 14 Test cup water supply valve 15 Jacket outlet valve 16 Test cup discharge valve 17 Connection hole 2 Gas constant temperature cooling unit 21 First temperature sensor 22 Cooling plate 23 First Controller 3 Second constant temperature heating unit 31 Second temperature sensor 32 Heating wire 33 Second Controller 4. Carbon dioxide measuring device 41 Measurement chamber 42 Carbon dioxide sensor 43 Display Converter 5. Gas-phase pressure balance bag 6 Gas Circulation Pump 7 Gas distributor 8 Measured water 9. First constant temperature heating unit 91 Heater 92 Third Temperature Sensor 93 Third Controller

Claims

1. Step S1: acquiring the type of precipitated inorganic salt in the sample water, one of the three items of inorganic carbon methyl orange alkalinity (Cmalk), pH, and total dissolved inorganic carbon (DIC) in the sample water, total dissolved solids content (TDS), and elements of target inorganic salts contributing to non-inorganic carbon methyl orange alkalinity, and their initial contents; Carbon dioxide concentration (CO ２ w) or the gas phase carbon dioxide concentration (PCO ２ Step S2 of continuously measuring the change over time of Step S3: obtaining a target amount of inorganic salt precipitate based on the data obtained in Step S1 and Step S2; Step S4: obtaining a target inorganic salt precipitation rate based on the precipitation amount obtained in step S3 and the time of step S2; A method for measuring the precipitation rate of an inorganic salt in water, comprising:

2. In step S1, the remaining two of the three inorganic carbon methyl orange alkalinity (C), pH, and total dissolved inorganic carbon (DIC) in the water are calculated according to the following formula: DIC=CO ２ w×(1+k’1 / (H ＋ )+k’1×k’2 / (H ＋ )^2 (1) Cmalk=50000×CO ２ w×(k’ １ / (H ＋ )+2k’ １ ×k’ ２ / (H ＋ )^2) (2) pH=-log(H ＋ (3) where DIC is the total dissolved inorganic carbon concentration in water (mol / L), and CO ２ w is the carbon dioxide concentration (mol / L) in the measured water, C is the inorganic carbon methyl orange alkalinity (mg / L, calcium carbonate standard) in the water, and H ＋ 2. The measurement method according to claim 1, wherein k′1 is the first dissociation constant of carbonic acid, and k′2 is the second dissociation constant of carbonic acid.

3. The target inorganic salt is calcium carbonate, and the water to be measured does not contain any other ions that contribute to non-inorganic carbon methyl orange alkalinity. Step S3 includes the following steps S311 to S313: In S311, t ０ When Cmark (t ０ ), CO ２ w(t ０ ) is known, and the start time t ０ When H ＋ (t ０ ) and DIC(t ０ ) and In S312, t １ CO at the time ２ w(t １ ) is known, and according to equation (5), t １ When H ＋ (t １ ) and calculate t according to equation (2). １ When Cmark (t １ ) and calculate t according to equation (4). １ DIC (t １ ) and (DIC(t ０ )-DIC(t １ ))×100×1000=(Cmalk(t ０ )-Cmalk(t １ )) (4) 2×CO ２ w(t ０ )-2×CO ２ w(t １ )=CO ２ w(t １ )×k'1 / H ＋ (t １ )-CO ２ w(t ０ )×k'1 / H ＋ (t ０ ) (5) In S313, the amount of precipitated calcium carbonate is calculated according to formula (6). CaCO ３ (s)(mg / L)=(DIC(t ０ )-DIC(t １ ))×10^5 (6) 3. The measuring method according to claim 2.

4. The precipitated inorganic salt is calcium phosphate, and the sample water has a non-inorganic carbon methyl orange alkalinity contributed by orthophosphate, and there are no other ions contributing to the non-inorganic carbon methyl orange alkalinity. Step S3 includes the following steps S321 to S323: In S321, t ０ When Cmark (t ０ ), CO ２ w(t ０ ) is known, and the start time t ０ When H ＋ (t ０ ) and DIC(t ０ ) and In S322, t １ CO at the time ２ w(t １ ) is known, and according to equation (7), t １ DIC (t １ ) and H ＋ (t １ ) and calculate t according to equation (2). １ When Cmark (t １ ) and DIC(t ０ )=DIC(t １ )=CO ２ w(t １ )×(1+k’1 / H ＋ (t １ )+k’1k’2 / (H ＋ (t １ )^2) (7) In S323, t ０ Tp(t ０ ) is known, and according to equation (9), DIP(t ０ ) is calculated, and Pmark(t ０ ) and calculate DIP(t １ ) and calculate the amount of precipitated calcium phosphate according to formula (14). (DIP(t ０ )-DIP(t １ )) / 2×2×50×1000=Cmalk(t ０ )+Pmalk(t ０ )-Cmalk(t １ )-Pmalk(t １ ) (8) DIP=Tp / 95 / 1000 (9) Pmalk=(PO ４ ３－ )×2×50000+(HPO ４ ２－ )×1×50000 (10) (PO) ４ ３－ )=Tp / 95 / 1000×kp1×kp2×kp3 / ((H ＋ )^3+(H ＋ )^2×kp1+(H ＋ )×kp1×kp2+kp1×kp2×kp3) (11) (HPO) ４ ２－ )=(PO ４ ３－ )×(H ＋ ) / kp3 (12) The amount of calcium phosphate precipitated is as follows: Ca ３ (PO ４ ) ２ (s)(mg / L)=(DIP(t ０ )-DIP(t １ )) / 2×310×1000 (14) where P is the inorganic phosphorus methyl orange alkalinity (mg / L, calcium carbonate standard), DIP is the total dissolved inorganic phosphorus concentration (mol / L), and T is the total dissolved inorganic phosphorus concentration (mg / L, PO ４ ３－ 3. The method according to claim 2, wherein kp1 is the primary ionization constant of phosphoric acid, kp2 is the secondary ionization constant of phosphoric acid, and kp3 is the tertiary ionization constant of phosphoric acid.

5. The target inorganic salt is magnesium silicate, and the water to be measured has non-inorganic carbon methyl orange alkalinity contributed by silicate, and there are no other ions contributing to non-inorganic carbon methyl orange alkalinity. Step S3 includes the following steps S331 to S333: In S331, t ０ When Cmark (t ０ ), CO ２ (t ０ ) is known, and the start time t ０ When H ＋ (t ０ ) and DIC(t ０ ) and In S332, t １ CO at the time ２ (t １ ) is known, and according to equation (7), t １ DIC (t １ ) and H ＋ (t １ ) and calculate t according to equation (2). １ When Cmark (t １ ) and DIC(t ０ )=DIC(t １ )=CO ２ (t １ )×(1+k’1 / H ＋ (t １ )+k’1k’2 / (H ＋ (t １ )^2) (7) In S333, t ０ Tsi (t ０ ) is known, and according to equation (16), DISi(t ０ ) is calculated, and Simalk(t ０ ) is calculated, and DISi(t １ ) is calculated, and the amount of precipitated magnesium silicate is obtained according to formula (19), (DISi(t ０ )-DISi(t １ ))×2×50×1000=Cmalk(t ０ )+Simalk(t ０ )-Cmalk(t １ )-Simalk(t １ ) (15) DISi=Tsi / 60 / 1000 (16) Simalk=50000×(Si(OH) ３ O － ) (17) (3i(9) ３ 9 － =DIｳi / (1+H ＋ / Ksi) (18) The amount of magnesium silicate precipitated is as follows: MgSiO ３ (s)(mg / L)=(DISi(t ０ )-DISi(t １ )×2×50×1000 (19) where DISi is the total dissolved inorganic silicon content (mol / L), Tsi is the total dissolved inorganic silicon content (mg / L, SiO ２ 3. The method according to claim 2, wherein Simalk is inorganic silicon methyl orange alkalinity (mg / L, calcium carbonate standard), Simalk is inorganic silicon methyl orange alkalinity (mg / L, calcium carbonate standard), and Ksi is the dissociation constant of silicic acid.

6. The target inorganic salt is colloidal silica, and the water to be measured has non-inorganic carbon methyl orange alkalinity contributed by silicate, and there are no other ions contributing to non-inorganic carbon methyl orange alkalinity. Step S3 includes the following steps S341 to S343: In S341, t ０ When Cmark (t ０ ), CO ２ w(t ０ ) is known, and the start time t ０ When H ＋ (t ０ ) and DIC(t ０ ) and In S342, t １ CO at the time ２ (t １ ) and Cmark(t １ ) is known, and according to equation (7), t １ DIC (t １ ) and H ＋ (t １ ) and calculate t according to equation (2). １ When Cmark (t １ ) and DIC(t ０ )=DIC(t １ )=CO ２ (t １ )×(1+k’1 / H ＋ (t １ )+k’1k’2 / (H ＋ (t １ )^2) (7) In S343, t ０ Tsi (t ０ ) is known, and according to equation (16), DISi(t ０ ) is calculated, and Simalk(t ０ ) is calculated, and DISi(t １ ) is calculated, and the amount of precipitated colloidal silica is calculated according to formula (21). (DIsi(t ０ )-DIsi(t １ ))×1×50×1000=-(Cmalk(t ０ )+Simalk(t ０ ))+(Cmalk(t １ )-Simalk(t １ )) (20) DISi=Tsi / 60 / 1000 (16) Simalk=50000×(Si(OH) ３ O － ) (17) (3i(9) ３ 9 － =DIｳi / (1+H ＋ / Ksi) (18) The amount of precipitated colloidal silica is as follows: 19 ２ (s)(s)0(s)(9). ０ SUCH(9) １ ))×1×60×1000 (21) 3. The measuring method according to claim 2.

7. In step S2, the carbon dioxide gas concentration PCO ２ The closed measuring device is provided with a gas circulation pump and a gas-phase carbon dioxide measuring device, and the carbon dioxide gas concentration PCO ２ is continuously recorded, and further, according to Henry's law, the carbon dioxide gas concentration PCO ２ The carbon dioxide concentration in water, CO ２ 2. The method of claim 1, further comprising converting the measured value to w.

8. An electronic device comprising a processor, a memory, and a computer program stored in the memory and operable on the processor, wherein the method for measuring the precipitation rate of an inorganic salt in water according to any one of claims 1 to 7 is realized when the processor executes the computer program.

9. A computer-readable storage medium having a computer program stored therein, the computer program being capable of realizing the method for measuring the precipitation rate of an inorganic salt in water according to any one of claims 1 to 7 when executed by a processor.

10. A system for measuring the precipitation rate of inorganic salts in water, comprising: a sealed measuring device for measuring the concentration of carbon dioxide; and the electronic device according to claim 8, wherein the electronic device further comprises an input / output module, and an output terminal of the sealed measuring device is signal-connected to the input / output module of the electronic device.

11. The measurement system described in claim 10, characterized in that the sealed measuring device includes a test container, a carbon dioxide measuring device, a first constant temperature heating unit, and a gas circulation pump, the water to be measured is provided in the test container, the inlet of the carbon dioxide measuring device is connected to the test container, and the outlet of the carbon dioxide measuring device is connected to the test container via the gas circulation pump, thereby forming a pipeline circuit through which carbon dioxide circulates, and the first constant temperature heating unit is provided in the test container and controls the temperature of the water to be measured to be constant.

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