KR101179846B1 - Flowrate measurement device and method using fluorescence density of flow in piping - Google Patents

Abstract

PURPOSE: A device and a method for measure a system flux using the intensity of fluorescent materials are provided to reduce error factors caused by transferring and elapsed time and to measure a system flux at the same time with a specimen sampling. CONSTITUTION: A device for measure a system flux using the intensity of fluorescent materials is as follows. Fluorescent materials are prepared. A fluorescent material infused solution is continuously injected into a pipe of a system at a constant flux. A specimen sampling is started and monitors the intensity of fluorescent mate with a fluorophotometer after confirming a mixing extent of the fluorescent material infused solution. The sampling is finished before a state of concentration equilibrium finishes. A standard solution is prepared. An intensity difference between the standard solution and sampling solution are respectively analyzed with the fluorophotometer. The flux is determined by using a value measured by the fluorophotometer.

Description

Flow rate measurement device and method using fluorescence density of flow in piping}

The present invention relates to a system flow measurement device and method using the intensity of the fluorescent material, and more particularly, a flow rate measuring device for calculating the flow rate in the field by measuring the fluorescence intensity using a fluorescent material as a tracer and a fluorescence photometer And to a method thereof.

The prior art injects a chemical tracer into the system to sample the sample at a location where the chemical tracer and the plant are sufficiently mixed. To prevent changes in the concentration of sampling samples, preprocessing in the field and then transfer to the laboratory to analyze the concentration with a precision analyzer (ICP-MS). The concentration decreases as the infusion is mixed with the plant water. Calculate the flow rate of the system by multiplying the injection rate by the dilution rate.

1 is a flow rate verification experimental system for explaining the principle of flow measurement in the prior art.

The flow rate verification experimental system of FIG. 1 is a water tank 1, a centrifugal pump 2, located upstream of the pipe and immediately after the chemical tracer injection point 6 for the injection of chemical tracers. Cone orifice (3) located at the bottom, a sampling point (7) for sampling the injected chemical tracer downstream of the pipe, and a turbine flow meter (4) And a water tank 5 and a plurality of valves 8 for measuring the water weight for the flow rate verification of the turbine flowmeter 4 installed in the pipe. When the water in the centrifuge by a pump (2) driven tank 1 is discharged to the flow rate Q ₀ through a conical orifice (3), a turbine flow meter (4), the flow rate Q _in the chemical tracer in the tracer injection point (6) When the gas is injected into the pipe, the mixed flow rate Q ₁ at the downstream of the pipe becomes (Q ₀ + Q _in ). On the other hand, the concentration of the injected tracer in said one tracer injection point (6) C _in, including a chemical tracer component injection, the concentration of when the injection chemical tracer is a thorough mixing at the downstream of the pipe in the water of the C _1, the reservoir If the concentration of the sample detected in the upstream storage tank is set to C ₀ , the following equation is established from the law of mass conservation (continuous equation using the chemical tracer flow rate and the tree water).

C ₀ Q ₀ + C _in Q _in = C ₁ Q ₁ --------------------- (One)

Q ₀ + Q _in = Q ₁ ---------------------- (2)

Substituting Equation (2) into Equation (1) and arranging for Q ₀ ,

----------------------- (3)

----------------------- (3)

.

From the above formula (3), knowing the injected chemical tracer flow rate Q _in , the sample concentrations C ₀ , C _in , and C ₁ at each of the upstream reservoir tracer injection point 6 and the sample collection point 7, The desired flow rate Q ₀ in the piping can be obtained.

The prior art includes the following problems in field applications.

(1) Only trace tracer chemical tracers are allowed.

In other words, when used in the laboratory, there is no restriction on the amount of chemical tracer injected, but when the power plant is applied, only a very small amount is allowed due to the strict restriction on the water quality management. Therefore, the concentration of the sampling sample is 10 ppb (10 x E-09) or less, and when a very small amount is injected, there is a problem in accurate flow rate measurement due to the resolution of the concentration analyzer, measurement error, and the like.

(2) There is a difficulty in determining the sampling start time.

In other words, the chemical tracer should be injected into the system using an injection pump, and then sampled after being sufficiently mixed with the system water. In general, in the straight pipe section, a representative sample can be obtained by sampling at a distance of more than 10 times the pipe diameter, but the mixing distance is determined according to the site conditions such as the injection condition and the presence of the curved pipe. Therefore, the mixing distance is determined by acquiring the data according to each condition through experiments in the laboratory, but the sample is sampled after sufficient time conservatively because the site conditions are different. This results in a longer sample sampling time and an increase in the amount of chemical tracer (foreign material) injected into the system, which may adversely affect power plant water quality management.

(3) There is difficulty in measuring the flow rate at all times.

In the prior art, after the sampled sample is preprocessed in the field, the sample is moved to a laboratory and analyzed using an ICP-MS, which reduces accuracy and makes it impossible to measure the flow rate in real time.

The present invention has been made to solve the conventional problems as described above. In order to measure the flow rate of the system using the fluorescent material as a tracer, a chemical tracer who knows the concentration and flow rate is injected into the system, mixed with the system water sufficiently, and the sample is sampled to measure the system flow rate with the dilution rate compared to the injection liquid. And to provide a device.

The flow measurement device using the fluorescent material of the present invention as a tracer and measuring the fluorescence intensity using a fluorescence photometer is used to calculate the flow rate in the field. Process volume pumps, probes with backflow check valves connected to flow measurement pipes, fluorophotometers installed on sampling lines connected to flow measurement pipes, recorders connected to fluorophotometers to check the intensity of fluorescent materials, and sampling It is characterized by consisting of a dragon bottle.

In addition, the flow measurement method of using the fluorescent material of the present invention as a tracer and measuring the fluorescence intensity using a fluorescence photometer to calculate the flow rate in the field, preparing rhodamine as an infusion solution as a fluorescent material and using a phylogenetic tree Preparing an injection solution (step 1); Continuously injecting the fluorescent material injection liquid into a pipe of a system at a constant flow rate (step 2); Confirming the degree of mixing of the fluorescent substance injection solution, starting sample sampling, and monitoring fluorescence intensity using a fluorophotometer (step 3); Completing sampling before the concentration equilibrium is over (step 4); Preparing a standard solution (step 5); Analyzing the difference in intensity between the standard solution and the sampling solution with a fluorophotometer (step 6); And determining the flow rate from the measurement result of the fluorophotometer (7 steps).

The flow rate measuring apparatus and method of the present invention uses a fluorescent material as a tracer, measures the fluorescence intensity using a fluorescence photometer, calculates the flow rate in the field, and has less error factors due to transport and time, and measures the system flow at the same time as the sample sampling. This has a possible effect.

1 is a laboratory flow rate verification system for explaining the conventional flow measurement principle.
2 is a block diagram of a fluorescent material injection system in a system flow measurement device using the intensity of the fluorescent material according to the present invention.
3 is a block diagram of a sampling facility in the system flow measurement apparatus using the intensity of the fluorescent material according to the present invention.
Figure 4 is a block diagram of a system flow measurement method using the intensity of the fluorescent material.
5 is a representative concentration equilibrium plot for determining sampling sample time points.

System flow measurement apparatus and method using the intensity of the fluorescent material of the present invention is characterized in the injection solution and analysis method. In other words, the present invention focuses on the fact that the intensity of fluorescence is proportional to the concentration of the fluorescent material, and the fluorescent material is selected as a chemical tracer, and instead of the concentration analysis, the intensity of the fluorescent material is measured by a fluorescence photometer and used for the flow rate calculation. Rhodamine (Thodamine WT) is selected from among fluorescent materials, and rhodamine can be measured in intensity with a fluorophotometer up to 0.01 ppb, but the solution to be analyzed is adjusted to include 10ppb intensities in consideration of resolution. Rhodamine is widely used due to its low adsorption rate on pipe walls and other advantages. Rhodamine has a good resolution even at a very small amount of 10ppb, so the flow rate can be measured by injecting a very small amount. In addition, in the case of power plants, the flow tracer injection, which is a foreign substance in the system water, can be minimized, so that the impact on the water quality management is small.

In addition, the system flow measurement device and the method using the intensity of the fluorescent material of the present invention is characterized by using a fluorescent photometer. That is, a fluorescence photometer is installed in the sample sampling line to measure the fluorescence intensity and recorded on the recorder. After the intensity reaches the equilibrium state, the sampling is started and the sampling is completed before the intensity drops. Therefore, it is possible to minimize the amount of fluorescent material injected into the system by minimizing the injection period by determining the sampling start and completion time through the recorder.

In addition, the system flow measurement device and the method using the intensity of the fluorescent material of the present invention is characterized in that the fluorescence photometer is connected to a computer to calculate. That is, the fluorescence intensities of the standard solution and the sample are measured by using a fluorescence photometer installed in the sampling line and transmitted to a computer. The final decision is made and multiplied by the injection solution to determine the system flow rate. Therefore, when constant flow measurement is required, the flow rate data can be obtained in real time from a computer by measuring a sampling sample with a fluorophotometer.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. The same reference numerals will be used for the same parts.

2 and 3 of the accompanying drawings is a configuration diagram of a system flow measurement device using the intensity of the fluorescent material according to the present invention, the tank 21 for storing a fluorescent tracer solution, a constant flow rate to the system to measure the fluorescent material Single process volumetric pump 22, which can be continuously and precisely injected into the probe, probe 23 having a non-return valve connected to the piping of the system to measure the flow rate, and is connected to the flow measurement pipe 24 A fluorescence photometer 26 for measuring the fluorescence intensity of the sample by passing the sampling sample installed in the sampling line 25, a recorder 27 connected to the fluorescence photometer 26 to check the intensity of the fluorescent substance, and a sample. It is comprised by the collection bottle 28.

Referring to the method for measuring the flow rate using the flow rate measuring apparatus according to the present invention as follows.

Figure 4 of the accompanying drawings shows a step-by-step procedure for the method for measuring the flow rate of the system using the intensity of the fluorescent material according to the present invention, the configuration and procedure for each step is as follows.

The first step is to prepare a chemical tracer, preparing rhodamine as an injection liquid as a fluorescent material and preparing a fluorescent material injection liquid using a phylogenetic tree. That is, when the chemical tracer (rhodamine, Rhodamine) including the fluorescent material is injected and mixed in the system, the injection solution is prepared so that the intensity of the fluorescent material is 10 ppb. This is because rhodamine has a good analysis at 10 ppb. Prepare the fluorescence infusion water using the plant water. An example of calculating the injection strength is as follows.

--------------------------------------------- (4)

--------------------------------------------- (4)

Where: C _in = injection strength (ppb)

C ₀ = expected intensity after dilution (= 10 ppb)

Q _i = Injection pump flow rate (L / sec)

Q ₀ = expected measuring system (L / sec)

therefore

The second step is a step of continuously injecting the fluorescent material injection liquid into the piping of the system at a constant flow rate, and the fluorescent material injection liquid prepared as shown in Figure 2 is injected into the center of the pipe 24 using the injection tube. At this time, high precision single-stroke positive displacement pump is used to continuously inject the fluorescent material at a constant flow rate, and a spring type check valve connected to the system to prevent backflow at the injection point ( Spring-loaded non-return valves are injected into the system via a probe (23) installed.

In the third step, after confirming the mixing degree of the fluorescent material injection solution, sample sampling is started and fluorescence intensity is monitored by using a fluorescence photometer. That is, the step of determining the sampling time of the sample sampling. Start sampling the sample after the injected solution is sufficiently mixed with the plant water. This is 10 times the diameter in the straight pipe section. However, if there is a device or structure in the middle that allows good bends or other mixing, sampling can be made at distances less than 10 times the diameter.

As shown in FIG. 3, the recorder 27 is connected to the fluorescence photometer 26 of the sampling pipe 25 to monitor the fluorescence intensity of the sample. Sampling is started after the intensity has reached equilibrium and a representative intensity change is shown in FIG. 5.

The fourth step is to complete the sampling before the concentration equilibrium is completed, and sample 30 samples in the shortest possible time from the start of sampling. Injection is continued until sampling is complete, and it is confirmed by using a fluorescence luminometer 27 that the concentration is in equilibrium. Sampling should be completed before the concentration equilibrium is over and time should be controlled to ensure that the phosphor is not excessively injected into the system.

The fifth step is to prepare a standard solution similar to the sample strength, using the fluid to be measured in the laboratory to prepare a standard solution similar to the expected sample strength. Dilute the infusion to the strength expected in the system using system water. This is because a standard solution having the same turbidity, PH, and the like as the sampling sample can be prepared by using a systematic water. Water containing chlorine cannot be used for the preparation of standard solutions. The dilution index for preparing the standard solution is calculated as follows.

-------------------------- (5)

-------------------------- (5)

Where DF = dilution rate

Q _i = Injection pump injection rate (L / sec)

Q ₀ = flow rate to be measured (L / sec)

If four dilutions are performed, the relevant formula is:

--------------------- (6)

--------------------- (6)

The sixth step analyzes the difference in intensity between the standard solution and the sampling solution with a fluorescence photometer, respectively, and analyzes the difference in intensity between the standard solution and the sampling solution through a fluorescence photometer 26, respectively. The fluorescence intensity measured by the fluorescence photometer 26 is transmitted to a computer to compare the fluorescence intensity of the standard solution to compensate for the dilution of the standard solution, and then multiply it by the injection flow rate to calculate the flow rate.

The seventh step is to determine the flow rate from the measurement result of the fluorophotometer 26 to determine the flow rate of the system to be measured by transmitting the fluorophotometer measurement results to a computer. The flow rate calculation calculates the flow rate of the system by multiplying the injection flow rate by the ratio of the fluorescence intensity of the sampled sample and the standard solution and the dilution rate of the standard solution. The flow rate calculation formula is as follows.

----------------- (7)

----------------- (7)

Where Q _in = injection flow rate (L / sec)

Q ₀ = Flow rate to be measured (L / sec)

DF _in = dilution rate of the standard solution

F _i = fluorescence intensity of standard solution

F ₀ = fluorescence intensity of sample solution

The prior art uses lithium as a chemical tracer to sample a sample, transfer it to a laboratory after pretreatment, analyze the concentration and calculate the flow rate using the dilution rate. Therefore, it takes a lot of time, there is a high possibility of error in the transport process, it is impossible to calculate the real-time flow rate.

In the present invention, by using the fluorescent material as a tracer and by measuring the fluorescence intensity using a fluorescence photometer to calculate the flow rate in the field, there is little error factor due to transportation and time. In addition, system flow measurement can be performed simultaneously with sample sampling.

In addition, the conventional technique is unable to confirm whether the concentration has reached equilibrium in taking a sample sampling time point, so that the sample is taken after a sufficient time. Excessively many samples were injected into the system, which adversely affected the collection management of the power plant.However, this method uses a recorder connected to the fluorometer to check the mixing of the injection solution and then start sampling. This can minimize the impact on the water quality management of the system.

The main feed water flow rate for nuclear power plants is an important variable used to calculate the heat output of a power plant. It is important not only for core management but also for safe operation of the reactor and directly affects the power output of the power plant. In order to confirm the accuracy of the venturi flowmeter installed in the field, an externally attached ultrasonic flowmeter is used, but it can be replaced by the present invention. If excess flow is indicated by venturi flow meter fouling, the power factor output can be retrieved by correcting the flow coefficient. In Yeonggwang Units 3 and 4, there is an output recovery (about 1%) experience. When the present invention is applied, it is possible to verify the venturi flowmeter in the system without installing the ultrasonic flowmeter, and calculate the flow rate by measuring the fluorescence intensity by injecting the fluorescent material, so that accurate results can be obtained even with a smaller amount of injection than the conventional technology. have.

It can be applied to the flow rate measurement of the power plant as well as the system which does not have a flow meter such as a petrochemical plant. In addition, there is a necessity to verify the accuracy of the flow meter in the general industry, but when it is impossible to verify in the laboratory by welding type, the present invention can verify the flow meter in the field.

The present invention has been described in detail with reference to the embodiments of the present invention, but the scope of the present invention is not limited thereto, and the scope of the present invention is substantially equivalent to the embodiments of the present invention.

In addition, as shown in the above description, the technique of the system flow measurement apparatus and method using the intensity of the fluorescent material according to the present invention is very simple, but the technical advantages of the present invention is very significant in that the technical effect is very large. Will be clear.

20 ---- flow measuring device
21 ---- tank
22 ---- Single process volumetric pump
23 ---- probe
24 ---- Pipe for flow measurement
25 ---- sampling line
26 ---- fluorescent photometer
27 ---- recorder
28 ---- Sample Collection Bottle

Claims (10)

delete Preparing a rhodamine as an infusion solution as a fluorescent substance and preparing a infusion solution using a phylogenetic tree (step 1);
Continuously injecting the fluorescent material injection liquid into a pipe of a system at a constant flow rate (step 2);
Confirming the degree of mixing of the fluorescent substance injection solution, starting sample sampling, and monitoring fluorescence intensity using a fluorophotometer (step 3);
Completing sampling before the concentration equilibrium is over (step 4);
Preparing a standard solution (step 5);
Analyzing the difference in intensity between the standard solution and the sampling solution with a fluorophotometer (step 6); And
System flow rate measurement method using the intensity of the fluorescent material, characterized in that the step of determining the flow rate from the measurement result of the fluorophotometer (7 steps). The method according to claim 2,
In the first step, the fluorescent material injection solution is prepared so that the intensity of the fluorescent material is 10ppb system flow measurement method using the intensity of the fluorescent material. The method according to claim 3,
The intensity of the fluorescent material injection solution is calculated by the formula (4) below the system flow measurement method using the intensity of the fluorescent material.

--------------------------------------------- (4)
Where: C _in = injection strength (ppb)
C ₀ = expected intensity after dilution (= 10 ppb)
Q _i = injection pump flow rate (L / sec)
Q ₀ = expected flow in the measuring system (L / sec)
therefore

The method according to claim 2,
In the third step, the sampling of the sample is performed at a distance of 10 times the diameter of the pipe when the pipe is straight, and 10 times the diameter of the curved pipe, and starts after the fluorescence intensity reaches the equilibrium. System flow measurement method using the strength of the material. The method according to claim 2,
In the fifth step, the standard solution is prepared by a solution having the same turbidity and pH as the sampling sample using the system water. The method of claim 6,
Dilution index for preparing the standard solution is calculated based on the following formula (5) and (6) system flow measurement method using the intensity of the fluorescent substance.

-------------------------- (5)
Where DF = dilution rate
Q _i = Injection pump injection rate (L / sec)
Q ₀ = flow rate to be measured (L / sec)
If four dilutions are performed, the relevant formula is:

--------------------- (6)
The method according to claim 2,
In the sixth step, the fluorescence intensity measured by the fluorescence photometer is transmitted to a computer to compare the fluorescence intensity of the standard solution to compensate for the dilution rate of the standard solution and multiply it by the injection flow rate to calculate the flow rate System flow measurement method using the strength of the material. The method according to claim 2,
In the seventh step, the flow rate calculation is to measure the flow rate of the system by calculating the flow rate of the system by multiplying the ratio of the fluorescence intensity of the sampling sample and the standard solution and the dilution rate of the standard solution by the injection flow rate Way. The method according to claim 9,
The flow rate calculation is calculated based on the following equation (7) system flow measurement method using the intensity of the fluorescent material.

.----------------- (7)
Where Q _in = injection flow rate (L / sec)
Q ₀ = Flow rate to be measured (L / sec)
DF _in = dilution rate of the standard solution
F _i = fluorescence intensity of standard solution
F ₀ = fluorescence intensity of sample solution

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