Method and apparatus for determining water level of steam generator

Abstract

The present application relates to a method and apparatus for determining water level of a steam generator. Unlike the prior art, the present application selects feedwater parameters measured in a feedwater channel connected to a steam generator and steam parameters measured in a steam outlet channel, uses the steam parameters and the feedwater parameters to indirectly calculate the feedwater density within a feedwater downcomer in the steam generator, and finally calculates the water level height of the steam generator. The present application does not require additional openings for sensor installation, does not damage the body structure of a steam generator device, and does not negatively affect the mechanical properties or thermal-hydraulic performance of the steam generator device.

Description

A method and apparatus for determining the water level in a steam generator. Technical Field

[0001] This application relates to the field of steam generator technology, and in particular to a method and apparatus for determining the water level in a steam generator. Background Technology

[0002] The steam generator is one of the key pieces of equipment in the design and operation of pressurized water reactor nuclear power plants. The foundation of steam generator water level control is the accurate measurement of the steam generator water level. Currently, the main methods for measuring the steam generator water level include: installing various sensors in the feedwater downcomer section of the steam generator, collecting parameters from the sensors to calculate the feedwater density in the downcomer channel, and then calculating the steam generator water level height based on the feedwater density in the downcomer channel.

[0003] This measurement method damages the structure of the steam generator and requires additional openings for sensor placement, which has a significant negative impact on the mechanical and thermal-hydraulic performance of the steam generator. Summary of the Invention

[0004] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of the claims.

[0005] A first aspect of this application provides a method for determining the water level in a steam generator, characterized in that the method includes:

[0006] The water supply parameters of the steam generator are obtained, and the steam parameters of the steam generator are obtained, wherein the water supply parameters are parameters measured in the water supply channel connected to the steam generator, and the steam parameters are parameters measured in the steam outlet channel of the steam generator.

[0007] The feedwater density in the feedwater downflow channel of the steam generator is determined based on the feedwater parameters and the steam parameters.

[0008] The water level in the steam generator is determined based on the water density in the water supply downflow channel.

[0009] This application provides a method for determining the water level of a steam generator. Unlike existing technologies, this method does not damage the main structure of the steam generator, does not measure parameters from inside the steam generator, does not require additional openings for sensor placement, and does not negatively affect the mechanical and thermal-hydraulic performance of the steam generator. Instead, it selects feedwater parameters measured in the feedwater channel connected to the steam generator and steam parameters measured in the steam outlet channel. The feedwater density in the feedwater drop channel of the steam generator is indirectly calculated using the steam parameters and feedwater parameters, and finally the water level height of the steam generator is calculated.

[0010] In some embodiments of this application, the steam parameters include at least one of the steam temperature and steam pressure of the steam outlet channel, and the water supply parameters include the water supply flow rate of the water supply channel;

[0011] Before determining the feedwater density in the feedwater downflow channel of the steam generator based on the feedwater parameters and the steam parameters, the method further includes:

[0012] Obtain the circulating flow rate in the steam generator, and obtain the feed water density in the feed water channel;

[0013] Determining the feedwater density in the feedwater downflow channel of the steam generator based on the feedwater parameters and the steam parameters includes:

[0014] The saturated water density of the steam generator in a saturated state is determined based on at least one of the steam temperature and the steam pressure.

[0015] The feedwater density in the feedwater downflow channel of the steam generator is determined based on the circulating flow rate, the saturated water density, the feedwater density in the feedwater channel, and the feedwater flow rate in the feedwater channel.

[0016] In some embodiments of this application, the water supply parameters further include the water supply temperature and the water supply pressure of the water supply channel;

[0017] The process of obtaining the water supply density of the water supply channel includes:

[0018] The water supply density of the water supply channel is determined based on the water supply temperature and the water supply pressure of the water supply channel.

[0019] In some embodiments of this application, the steam parameters further include the steam flow rate of the steam outlet channel;

[0020] The step of obtaining the circulating flow rate in the steam generator includes:

[0021] The circulation flow rate in the steam generator is determined based on the steam flow rate.

[0022] In some embodiments of this application, determining the feedwater density in the feedwater downflow channel of the steam generator based on the circulating flow rate, the saturated water density, the feedwater density of the feedwater channel, and the feedwater flow rate of the feedwater channel includes:

[0023] Multiply the water flow rate of the water supply channel by the water supply density of the water supply channel to obtain the first multiplication result;

[0024] Subtracting the circulating flow rate in the steam generator from the value 1 yields the first subtraction result;

[0025] Multiply the first subtraction result, the water flow rate of the water supply channel, and the saturated water density to obtain the second multiplication result;

[0026] Add the first multiplication result to the second multiplication result to obtain the first sum result;

[0027] Multiply the circulating flow rate by the water supply flow rate of the water supply channel to obtain the third multiplication result;

[0028] Divide the first summation result by the third multiplication result to obtain the feedwater density in the feedwater downflow channel of the steam generator.

[0029] In some embodiments of this application, before determining the water level in the steam generator based on the feedwater density in the feedwater downflow channel, the method further includes:

[0030] The following information is obtained: the first vertical height between the first contact port and the second contact port between the pressure channel of the steam generator and the body of the steam generator; the water pressure difference and water density in the pressure channel; and the second vertical height between the first contact port and the top of the steam generator, wherein the horizontal height of the first contact port is lower than the horizontal height of the second contact port.

[0031] The saturated steam density of the steam generator in a saturated state is determined based on the steam temperature or the steam pressure.

[0032] The step of determining the water level in the steam generator based on the feedwater density in the feedwater downflow channel includes:

[0033] The water level in the steam generator is determined based on the water pressure difference in the pressure channel, the water density in the pressure channel, the gravitational acceleration, the saturated steam density, the first vertical height, the second vertical height, and the feedwater density in the feedwater descending channel of the steam generator.

[0034] In some embodiments of this application, determining the water level in the steam generator based on the water pressure difference in the pressure-inducing channel, the water density in the pressure-inducing channel, the gravitational acceleration, the saturated steam density, the first vertical height, the second vertical height, and the feedwater density in the feedwater downflow channel of the steam generator includes:

[0035] Multiply the water density in the pressure channel, the gravitational acceleration, and the first vertical height to obtain the fourth multiplication result;

[0036] Multiplying the saturated vapor density, the gravitational acceleration, and the second vertical height yields the fifth multiplication result;

[0037] Subtract the result of multiplying the water pressure difference in the pressure channel with the fourth result to obtain the second subtraction result;

[0038] Add the second subtraction result to the fifth multiplication result to obtain the second addition result;

[0039] Subtracting the saturated steam density from the water level in the steam generator yields the third subtraction result;

[0040] Multiplying the third subtraction result by the gravitational acceleration yields the sixth multiplication result;

[0041] Divide the second sum by the sixth multiplication result to obtain the water level in the steam generator.

[0042] A second aspect of this application provides a device for determining the water level of a steam generator, the device comprising:

[0043] A water supply parameter acquisition module is used to acquire the water supply parameters of the steam generator, wherein the water supply parameters are parameters measured in the water supply channel connected to the steam generator;

[0044] A steam parameter acquisition module is used to acquire the steam parameters of the steam generator, wherein the steam parameters are parameters measured in the steam outlet channel of the steam generator.

[0045] The processing module is used to determine the feedwater density in the feedwater downflow channel of the steam generator based on the feedwater parameters and the steam parameters, and to determine the water level height in the steam generator based on the feedwater density in the feedwater downflow channel.

[0046] A third aspect of this application provides an electronic device, including: at least one control processor and a memory for communicatively connecting to the at least one control processor; the memory stores instructions executable by the at least one control processor, the instructions being executed by the at least one control processor to enable the at least one control processor to perform the above-described method for determining the water level of a steam generator.

[0047] A fourth aspect of this application provides a computer-readable storage medium storing computer-executable instructions for causing a computer to execute the above-described method for determining the water level of a steam generator.

[0048] It is understood that the beneficial effects of the second to fourth aspects compared with the related technologies are the same as the beneficial effects of the first aspect compared with the related technologies. Please refer to the relevant description in the first aspect above, which will not be repeated here. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 is a flowchart illustrating an embodiment of the method for determining the water level of a steam generator provided in this application;

[0051] Figure 2 is a structural schematic diagram of an embodiment of the steam generator provided in this application;

[0052] Figure 3 is another flowchart illustrating an embodiment of the method for determining the water level of a steam generator provided in this application;

[0053] Figure 4 is a structural schematic diagram of an embodiment of the electronic device provided in this application. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0055] The steam generator is one of the key pieces of equipment in the design and operation of pressurized water reactor (PWR) nuclear power plants. As a heat exchanger, it transfers heat from the primary coolant to the secondary feedwater, generating saturated steam to supply the secondary power plant. Simultaneously, as a connecting device between the primary and secondary loops, the steam generator forms a second line of defense against radioactive leakage. In PWR design, the steam generator water level is typically controlled near a setpoint determined by the load. This prevents the water level from becoming too high during transients, which could flood the dryer, increase the humidity of the outlet steam, and damage the turbine blades. Conversely, it prevents the water level from becoming too low, which could cause the primary coolant temperature to rise, leading to insufficient core cooling and damage to the steam generator heat transfer tubes. The foundation of steam generator water level control is the accurate measurement of the steam generator water level.

[0056] Currently, water level measurement in steam generators for engineering applications can be achieved based on the differential pressure method. Changes in water level are converted into changes in differential pressure, and the actual water level within the steam generator is obtained based on the correlation between differential pressure and water level. For example, the steam generator water level measurement is set up in the annular space of the feedwater downcomer channel, using the differential pressure measurement principle, as shown in Figure 2. The upper pressure tap is connected to a condenser tank to obtain a stable reference liquid column, which is connected to one side of the differential pressure sensor. The lower pressure tap is connected to the other side of the differential pressure sensor. From this, the pressure at various points can be obtained: P A =P s +ρgh+ρ s g(Lh) (1) P B =P s +ρ r gH (2) ΔP=P B -P A =ρ r gH-ρgh-ρ s g(Lh) (3)

[0057] In the formula, ρ is the density of the mixed feedwater in the descending channel, ρ s ρ is the vapor density. r The reference is the water density inside the pipe.

[0058] When the steam generator is full of water, the corresponding pressure difference is: ΔP 100 =(ρ r -ρ+ρ s )gH-ρ s gL (4)

[0059] In current engineering design, the pressure difference of the steam generator is calibrated at a specific power level, and the corresponding full-water level pressure difference ΔP is calculated using the aforementioned pressure difference relationship. 100 The water level in the steam generator is calculated using the following relationship:

[0060] Due to the pressure difference ΔP at full water level 100 This calibration is based on a specific power level. During the process of a nuclear power unit going from cold shutdown to full-power operation, the density of the medium inside the steam generator changes significantly, resulting in a large pressure difference ΔP at the full water level. 100 The water level can also change significantly, therefore the above-mentioned method for measuring the water level in a steam generator has a large error.

[0061] Another method for measuring the water level in a steam generator involves installing pressure and temperature sensors in the feedwater descending section of the steam generator. By collecting sensor data, the density ρ of the mixed feedwater in the descending channel is calculated, and then the water level in the steam generator is calculated using ρ.

[0062] However, this method damages the main structure of the steam generator and requires additional openings to accommodate sensors, which has a significant impact on the mechanical and thermal-hydraulic performance of the steam generator.

[0063] Therefore, referring to Figure 1, this application embodiment provides a method for determining the water level of a steam generator. This method is applied to a controller, which can be a server, an electronic device, or a mobile terminal, etc., without specific limitations here. The method includes the following steps S110 to S130:

[0064] Step S110: Obtain the feedwater parameters of the steam generator and the steam parameters of the steam generator.

[0065] In this step, the feedwater parameters are measured in the feedwater channel connected to the steam generator. The feedwater channel is used to supply water to the steam generator, and it can be a feedwater pipe connected to the steam generator. Feedwater parameters are collected by installing relevant sensors in the feedwater channel; for example, a flow sensor can be installed in the feedwater channel to collect the feedwater flow rate as the feedwater parameter.

[0066] In this step, the steam parameters are measured in the steam outlet channel of the steam generator. Steam parameters can be collected by installing sensors in the steam outlet channel; for example, a temperature sensor can be installed in the steam outlet channel to collect the steam temperature as a steam parameter.

[0067] It should be noted that the controller can communicate with various sensors, and the parameters can be transmitted to the controller through the sensors after measurement. Steam parameters and feedwater parameters will be described in detail in subsequent embodiments, and are not specifically limited here.

[0068] Step S120: Determine the feedwater density in the feedwater downflow channel of the steam generator based on the feedwater parameters and steam parameters.

[0069] In this step, the feedwater density in the feedwater downflow channel of the steam generator is determined using the feedwater parameters measured from the feedwater channel connected to the steam generator and the steam parameters measured from the steam outlet channel of the steam generator.

[0070] In one implementation, the correspondence between the feedwater parameters, steam parameters and the feedwater density in the feedwater downflow channel of the steam generator can be preset in advance to construct a relationship table. For example, after obtaining the feedwater parameters and steam parameters, the corresponding feedwater density in the feedwater downflow channel can be found by looking up the table and using the correspondence between them.

[0071] In another implementation, a relationship (relationship function) can be established between the feedwater parameters, steam parameters and the feedwater density in the feedwater downflow channel of the steam generator. For example, after obtaining the feedwater parameters and steam parameters, the feedwater density in the feedwater downflow channel can be calculated using the relationship.

[0072] Step S130: Determine the water level in the steam generator based on the water density in the water supply downflow channel.

[0073] After receiving the steam and feedwater parameters collected by the sensor, the controller of this method executes steps S120 and S130 to obtain the final calculated water level in the steam generator. Here, the water level in the steam generator is the water level in the feedwater downflow channel, for example, h in Figure 2.

[0074] Unlike existing technologies, the embodiments of this application do not damage the main structure of the steam generator, do not measure parameters from inside the steam generator, do not require additional openings for sensor placement, and do not negatively affect the mechanical and thermal-hydraulic performance of the steam generator. Instead, they select feedwater parameters measured in the feedwater channel connected to the steam generator and steam parameters measured in the steam outlet channel. The feedwater density in the feedwater drop channel of the steam generator is indirectly calculated using the steam parameters and feedwater parameters, and finally the water level height of the steam generator is calculated, thus solving the defects of the existing technology.

[0075] In some embodiments of this application, the steam parameters include at least one of the steam temperature and steam pressure of the steam outlet channel, and the feedwater parameters include the feedwater flow rate of the feedwater channel.

[0076] Before determining the feedwater density in the feedwater downflow channel of the steam generator based on the feedwater parameters and steam parameters in step S120, the method further includes the following step S210:

[0077] Step S210: Obtain the circulating flow rate in the steam generator and the feedwater density in the feedwater channel.

[0078] Step S120, determining the feedwater density in the feedwater downflow channel of the steam generator based on the feedwater parameters and steam parameters, includes the following steps S310-S320:

[0079] Step S310: Determine the saturated water density of the steam generator under saturated conditions based on at least one of the steam temperature and steam pressure.

[0080] Step S320: Determine the feedwater density in the feedwater downflow channel of the steam generator based on the circulating flow rate, saturated water density, feedwater density in the feedwater channel, and feedwater flow rate in the feedwater channel.

[0081] In this embodiment, the steam parameters include at least one of the steam temperature and steam pressure at the steam outlet channel. The purpose of obtaining the steam temperature and steam pressure is to determine the saturated water density of the steam generator under saturated conditions. The steam temperature and steam pressure are acquired by temperature and pressure sensors and then transmitted to the controller. For example, a temperature sensor is installed at the steam outlet channel to acquire the steam temperature at the steam outlet channel, or a pressure sensor is installed at the steam outlet channel to acquire the pressure and temperature at the steam outlet channel.

[0082] In some implementations, the saturated water density can be calculated using either steam temperature or steam pressure via a relevant formula. It should be noted that both the formulas for calculating saturated water density based on steam temperature and those based on steam pressure are common knowledge in the field and will not be elaborated upon here.

[0083] In other implementations, the saturated water density of the steam generator under saturated conditions can be determined by combining steam temperature and steam pressure. For example, the saturated water density can be calculated once using steam temperature and a calculation formula, and then again using steam pressure and a calculation formula. Appropriate weights are then assigned to the saturated water densities obtained from different parameters. Finally, the final saturated water density is determined using the saturated water densities calculated in both methods and their weights. Compared to schemes that calculate using only one parameter, this scheme can assign different weights to steam pressure and steam temperature based on the actual conditions in the steam generator, thus balancing the participation of the two parameters and improving the accuracy of the final saturated water density calculation.

[0084] In this embodiment, the feedwater parameters include the feedwater flow rate of the feedwater channel. The purpose of the feedwater flow rate is to determine the feedwater density in the feedwater downflow channel of the steam generator in conjunction with other parameters. For example, a flow sensor can be installed in the feedwater channel, and the feedwater flow rate can be collected by the flow sensor and finally transmitted to the controller.

[0085] In this embodiment, it is also necessary to obtain two parameters: the circulating flow rate in the steam generator and the feedwater density in the feedwater channel. The purpose of obtaining these two parameters is to determine the feedwater density in the feedwater downflow channel of the steam generator in conjunction with the other parameters.

[0086] The circulation flow rate in a steam generator is mainly characterized by the circulation ratio, which is defined as the mass of circulating water required for the steam generator to produce one unit mass of steam. There are several ways to determine this parameter, the circulation flow rate in a steam generator.

[0087] In some implementations, the circulating flow rate in the steam generator can be determined by the steam flow rate of the steam outlet channel. For example, the steam parameters mentioned above also include the steam flow rate of the steam outlet channel. By setting a flow sensor in the steam outlet channel, the steam flow rate of the steam outlet channel is collected by the flow sensor, and the circulating flow rate is calculated by combining the steam flow rate with relevant calculation formulas. This method is simpler than other methods of obtaining the circulating flow rate.

[0088] In some implementations, the water supply density of the water supply channel is obtained in the following two ways:

[0089] The first method involves installing density sensors in the water supply channel to collect the water density. The advantage of this method is that it requires fewer sensors and can eliminate some calculation steps.

[0090] The second method involves installing temperature and pressure sensors in the water supply channel. These sensors collect data on the water temperature and pressure, and the water density is then determined using these parameters. Compared to the first method, this method offers higher accuracy in data acquisition via temperature and pressure sensors, thus improving the precision of the final water density calculation. The formula for calculating density from temperature and pressure is well-known in the field and will not be elaborated upon here.

[0091] In step S320, the feedwater density in the feedwater downflow channel of the steam generator is determined based on the circulating flow rate, saturated water density, feedwater density in the feedwater channel, and feedwater flow rate in the feedwater channel.

[0092] In some implementations, the correspondence between four parameters—circulation flow rate, saturated water density, water supply density in the water supply channel, and water supply flow rate in the water supply channel—and the water supply density in the water supply drop channel can be set in advance, and the corresponding values ​​can be found by looking up a table.

[0093] In other implementations, the four parameters of circulating flow rate, saturated water density, feed water density in the feed water channel, and feed water flow rate in the feed water channel can be used as inputs through relevant calculation formulas, and the feed water density in the feed water downflow channel in the steam generator can be used as the output value.

[0094] This embodiment determines the feedwater density in the feedwater downflow channel of the steam generator based on four parameters: circulation flow rate, saturated water density, feedwater density in the feedwater channel, and feedwater flow rate in the feedwater channel. It can quickly calculate the feedwater density in the feedwater downflow channel of the steam generator without damaging the steam generator structure.

[0095] In some embodiments of this application, the feedwater density in the feedwater downflow channel of the steam generator is determined based on the circulating flow rate, saturated water density, feedwater density in the feedwater channel, and feedwater flow rate in the feedwater channel, including the following steps S410 to S460:

[0096] Step S410: Multiply the water flow rate of the water supply channel by the water supply density of the water supply channel to obtain the first multiplication result.

[0097] Step S420: Subtract the circulating flow rate in the steam generator from the value 1 to obtain the first subtraction result.

[0098] Step S430: Multiply the first subtraction result, the water supply flow rate of the water supply channel, and the saturated water density to obtain the second multiplication result.

[0099] Step S440: Add the first multiplication result to the second multiplication result to obtain the first addition result.

[0100] Step S450: Multiply the circulating flow rate by the water supply flow rate of the water supply channel to obtain the third multiplication result.

[0101] Step S460: Divide the first summation result by the third multiplication result to obtain the feedwater density in the feedwater downflow channel of the steam generator.

[0102] The formulas for steps S410-S460 are shown below:

[0103] Among them, Q f It is the water supply flow rate of the water supply channel, ρ f CR is the feedwater density in the feedwater channel, and CR is the circulating flow rate in the steam generator. ρ is the saturated water density, and ρ is the water supply density in the water supply downflow channel.

[0104] This embodiment, based on four parameters—circulation flow rate, saturated water density, feedwater density in the feedwater channel, and feedwater flow rate in the feedwater channel—can ultimately calculate the feedwater density in the feedwater downflow channel of the steam generator without damaging the steam generator structure, by setting calculation steps.

[0105] In some embodiments of this application, before determining the water level in the steam generator based on the feedwater density in the feedwater downflow channel, the method further includes the following steps S510 and S520:

[0106] Step S510: Obtain the first vertical height between the first contact port and the second contact port between the pressure channel of the steam generator and the steam generator body, the water pressure difference and water density in the pressure channel, and the second vertical height between the first contact port and the top of the steam generator, wherein the horizontal height of the first contact port is lower than the horizontal height of the second contact port.

[0107] In this step, referring to Figure 2, steam generators in the nuclear power field typically have a pressure-sensing channel connected to a differential pressure sensor and a condenser. The pressure-sensing channel can be a pressure-sensing pipe, with one end connected to the main body of the steam generator (let's call the contact port the first contact port). The other end of the pressure-sensing pipe connects to a differential pressure sensor, then to a condenser, and finally to the main body of the steam generator (let's call the contact port the second contact port). The horizontal height of the first contact port is lower than that of the second contact port. The first vertical height between the first and second contact ports, and the second vertical height between the first contact port and the top of the steam generator, are related to the steam generator's main body design and can be considered constants; no specific limitations are made here. The water pressure difference in the pressure-sensing channel can be obtained by subtracting the pressure parameters measured by the differential pressure sensor. The water density in the pressure-sensing channel can be considered constant because the water density in the reference pipe (a section of the pressure-sensing pipe) remains essentially unchanged during the operation of the nuclear power unit.

[0108] The parameters mentioned in step S510 can be obtained without damaging the structure of the steam generator.

[0109] Step S520: Determine the saturated steam density of the steam generator under saturated conditions based on the steam temperature or steam pressure.

[0110] This can be determined using relevant formulas, the specific formulas of which are common knowledge in the field and will not be elaborated here;

[0111] Step S130 determines the water level in the steam generator based on the feedwater density in the feedwater downflow channel, including the following step S610:

[0112] Step S610: Determine the water level in the steam generator based on the water pressure difference in the pressure channel, the water density in the pressure channel, the gravitational acceleration, the saturated steam density, the first vertical height, the second vertical height, and the feedwater density in the feedwater descending channel of the steam generator.

[0113] This embodiment can determine the water level in the steam generator without damaging the steam generator structure by using the water pressure difference in the pressure channel, the water density in the pressure channel, the gravitational acceleration, the saturated steam density, the first vertical height, the second vertical height, and the feedwater density in the feedwater descending channel of the steam generator.

[0114] In some embodiments of this application, determining the water level in the steam generator based on the water pressure difference in the pressure-tapping channel, the water density in the pressure-tapping channel, the gravitational acceleration, the saturated steam density, the first vertical height, the second vertical height, and the feedwater density in the feedwater downflow channel of the steam generator includes the following steps S710 to S770:

[0115] Step S710: Multiply the water density, gravitational acceleration, and first vertical height in the pressure channel to obtain the fourth multiplication result.

[0116] Step S720: Multiply the saturated steam density, gravitational acceleration, and second vertical height to obtain the fifth multiplication result.

[0117] Step S730: Subtract the water pressure difference in the pressure channel from the fourth multiplication result to obtain the second subtraction result.

[0118] Step S740: Add the second subtraction result to the fifth multiplication result to obtain the second addition result.

[0119] Step S750: Subtract the saturated steam density from the water level in the steam generator to obtain the third subtraction result.

[0120] Step S760: Multiply the third subtraction result by the gravitational acceleration to obtain the sixth multiplication result.

[0121] Step S770: Divide the result of the second addition by the result of the sixth multiplication to obtain the water level in the steam generator.

[0122] The formulas for steps S710 to S770 are as follows:

[0123] Where ΔP is the water pressure difference in the pressure-inducing channel, ρ s ρ is the saturated vapor density, g is the gravitational acceleration, L is the product of the second vertical height, and ρ is the saturated vapor density. rρ is the water density in the pressure channel, H is the product of the first vertical height, ρ is the feedwater density in the feedwater downflow channel, and h is the water level in the steam generator.

[0124] This embodiment calculates the water level in the steam generator without damaging the generator structure by using the water pressure difference in the pressure channel, the water density in the pressure channel, the gravitational acceleration, the saturated steam density, the first vertical height, the second vertical height, and the feedwater density in the feedwater descending channel of the steam generator.

[0125] Referring to Figures 2 and 3, in order to achieve accurate measurement of the water level in the steam generator, the pressure difference relationship in the generator is further analyzed. The water level in the steam generator can be calculated using formula (7):

[0126] In this formula, the water density in the reference tube remains essentially constant during the operation of the nuclear power unit, ρ r The range H and the height L of the lower pressure tap from the top of the steam generator can be considered constants. Therefore, the key to calculating the water level in the steam generator is to obtain the steam density ρ. s The density ρ of the mixed feedwater in the descending channel.

[0127] The following is the derivation of formula (7):

[0128] For a steam generator, the corresponding saturated steam density ρ can be calculated from the steam temperature. s and saturated water density That is, ρ s =f1(T s (8)

[0129] f1 and f2 are related calculation functions or formulas. The subsequent f3-f6 are similar. Among them, f5 and f6 give specific calculation formulas, while f1-f4 are common knowledge in the field and will not be elaborated here.

[0130] The water level measurement in the steam generator is the water level in the feedwater downcomer channel. The feedwater in the downcomer channel is a mixture of inlet feedwater and steam-water separation recirculation water. The density ρ of the mixed feedwater in the downcomer channel can be calculated using the following formula:

[0131] As the operating status of the steam generator changes, the steam generator circulation ratio will also change synchronously, and the recirculation flow rate will change accordingly. At the same time, when the nuclear power unit operates under different loads, the secondary loop feedwater temperature and steam generator pressure will also change, and the feedwater density and steam density will change accordingly.

[0132] In engineering design, the circulation flow rate on the secondary side of a steam generator is usually characterized by the circulation ratio. The circulation ratio is defined as the mass of circulating water required for the steam generator to produce one unit mass of steam.

[0133] In the formula, CR is the cycle ratio, and Q... r For recirculation flow, Q f This refers to the water supply flow rate.

[0134] Therefore, the secondary circulation flow rate of the steam generator can be obtained by the following formula: Q r =(CR-1)Q f (12)

[0135] As the steam flow rate changes, the recirculation ratio also changes, i.e.: CR = f3(Q) s (13)

[0136] Therefore, the secondary circulation flow rate of the steam generator can be further calculated using the following formula: Q r =(f3(Q3)-1)Q f (14)

[0137] The feed water density can be calculated from the feed water pressure and feed water temperature, i.e.: ρ f =f4(P f ,T f (15)

[0138] Therefore, the density ρ of the mixed feedwater in the descending channel can be further calculated using the following formula:

[0139] The water level in the steam generator can be further calculated using the following formula:

[0140] Referring to Figure 1, in order to improve the accuracy of water level monitoring in the steam generator, this embodiment installs a flow sensor, a pressure sensor, and a temperature sensor on the water supply channel (such as a water supply pipe) at the inlet of the steam generator, and installs a flow sensor and a temperature sensor on the steam outlet channel (such as a steam pipe) of the steam generator, so as to achieve high-precision measurement of the water level in the steam generator.

[0141] Referring to Figure 3, the specific implementation method of this embodiment includes:

[0142] Step S810: Measure the steam flow rate Q at the outlet of the steam generator using a flow sensor installed on the steam pipeline. s The controller determines the steam flow rate Q. s The internal circulation flow rate Q of the steam generator was calculated. r .

[0143] Step S820: Measure the steam temperature T at the outlet of the steam generator using a temperature sensor installed on the steam pipeline. s The saturated steam density ρ is calculated by the controller based on the steam temperature. s and saturated water density

[0144] Step S830: Measure the feedwater temperature T at the feedwater inlet of the steam generator using temperature and pressure sensors installed in the feedwater pipeline. f Water supply pressure P f The controller adjusts the pressure P according to the water supply pressure. f and water supply temperature T f The water supply density ρ of the water supply pipeline was calculated. f .

[0145] Step S840: Measure the water flow rate Q using a flow sensor installed in the water supply pipeline. f The controller determines the internal circulation flow rate Q of the steam generator. r Water flow rate Q f Water supply density ρ f saturated water density The feedwater density ρ in the feedwater drop section is calculated.

[0146] Step S850: Obtain the water level and pressure difference ΔP of the steam generator through the controller, and based on the water level and pressure difference ΔP of the steam generator and the steam density ρ... s The steam generator water level is calculated from the feedwater density ρ in the feedwater drop section.

[0147] This embodiment avoids directly installing sensors in the steam generator body by setting sensors in the water supply pipe and steam pipe, thus avoiding affecting the mechanical and thermal-hydraulic performance of the steam generator equipment.

[0148] As mentioned earlier, the feedwater density in the feedwater downcomer of a nuclear power unit changes significantly during the transition from cold shutdown to full-power operation. This embodiment reduces the steam generator water level measurement error caused by the feedwater density variation in the downcomer section by accurately calculating this density. Published literature indicates that the feedwater density variation in the downcomer section can cause approximately 4% of the steam generator water level measurement error, meaning that this embodiment is expected to improve the steam generator water level measurement accuracy by approximately 4%.

[0149] Some embodiments of this application provide a device for determining the water level of a steam generator. The device includes a feedwater parameter acquisition module, a steam parameter acquisition module, and a processing module. Specifically:

[0150] The feedwater parameter acquisition module is used to acquire the feedwater parameters of the steam generator. The feedwater parameters are measured in the feedwater channel connected to the steam generator.

[0151] The steam parameter acquisition module is used to acquire the steam parameters of the steam generator, which are measured in the steam outlet channel of the steam generator.

[0152] The processing module is used to determine the feedwater density in the feedwater downflow channel of the steam generator based on the feedwater parameters and steam parameters, and to determine the water level height in the steam generator based on the feedwater density in the feedwater downflow channel.

[0153] It should be noted that the steam generator water level determination device provided in this embodiment is based on the same inventive concept as the steam generator water level determination method described above. Therefore, the relevant content of the steam generator water level determination method described above also applies to the content of the steam generator water level determination device. Therefore, it will not be repeated here.

[0154] As shown in Figure 4, this application embodiment also provides an electronic device, which includes:

[0155] At least one memory;

[0156] At least one processor;

[0157] At least one program;

[0158] The program is stored in memory, and the processor executes at least one program to implement the bus interval warning method described above in this application.

[0159] This electronic device can be any smart terminal, including mobile phones, tablets, personal digital assistants (PDAs), and in-vehicle computers.

[0160] The electronic devices according to embodiments of this application will now be described in detail.

[0161] The processor 1600 can be implemented using a general-purpose central processing unit (CPU), microprocessor, application specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this application.

[0162] The memory 1700 can be implemented as a read-only memory (ROM), static storage device, dynamic storage device, or random access memory (RAM). The memory 1700 can store the operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the program code is stored in the memory 1700 and is called and executed by the processor 1600 to execute the bus interval warning method of the embodiments of this application.

[0163] The input / output interface 1800 is used to implement information input and output.

[0164] The communication interface 1900 is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0165] Bus 2000 transmits information between various components of the device (e.g., processor 1600, memory 1700, input / output interface 1800, and communication interface 1900);

[0166] The processor 1600, memory 1700, input / output interface 1800 and communication interface 1900 are connected to each other within the device via bus 2000.

[0167] This application embodiment also provides a storage medium, which is a computer-readable storage medium storing computer-executable instructions for causing a computer to execute the above-described bus interval warning method.

[0168] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0169] The embodiments described in this application are intended to more clearly illustrate the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. Those skilled in the art will know that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0170] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0171] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0172] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0173] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0174] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0175] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0176] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0177] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0178] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause an electronic device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0179] The above is a detailed description of the preferred embodiments of this application. However, the embodiments of this application are not limited to the above-described implementation methods. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the embodiments of this application. All such equivalent modifications or substitutions are included within the scope defined by the claims of the embodiments of this application.

Claims

1. A method for determining the water level in a steam generator, characterized in that, The method includes: The water supply parameters of the steam generator are obtained, and the steam parameters of the steam generator are obtained, wherein the water supply parameters are parameters measured in the water supply channel connected to the steam generator, and the steam parameters are parameters measured in the steam outlet channel of the steam generator. The feedwater density in the feedwater downflow channel of the steam generator is determined based on the feedwater parameters and the steam parameters. The water level in the steam generator is determined based on the water density in the water supply downflow channel.

2. The method for determining the water level in a steam generator according to claim 1, characterized in that, The steam parameters include at least one of the steam temperature and steam pressure of the steam outlet channel, and the water supply parameters include the water supply flow rate of the water supply channel. Before determining the feedwater density in the feedwater downflow channel of the steam generator based on the feedwater parameters and the steam parameters, the method further includes: Obtain the circulating flow rate in the steam generator, and obtain the feed water density in the feed water channel; Determining the feedwater density in the feedwater downflow channel of the steam generator based on the feedwater parameters and the steam parameters includes: The saturated water density of the steam generator in a saturated state is determined based on at least one of the steam temperature and the steam pressure. The feedwater density in the feedwater downflow channel of the steam generator is determined based on the circulating flow rate, the saturated water density, the feedwater density in the feedwater channel, and the feedwater flow rate in the feedwater channel.

3. The method for determining the water level in a steam generator according to claim 2, characterized in that, The water supply parameters also include the water supply temperature and the water supply pressure of the water supply channel; The process of obtaining the water supply density of the water supply channel includes: The water supply density of the water supply channel is determined based on the water supply temperature and the water supply pressure of the water supply channel.

4. The method for determining the water level in a steam generator according to claim 2, characterized in that, The steam parameters also include the steam flow rate of the steam outlet channel; The step of obtaining the circulating flow rate in the steam generator includes: The circulation flow rate in the steam generator is determined based on the steam flow rate.

5. The method for determining the water level in a steam generator according to claim 2, characterized in that, Determining the feedwater density in the feedwater downflow channel of the steam generator based on the circulating flow rate, the saturated water density, the feedwater density in the feedwater channel, and the feedwater flow rate in the feedwater channel includes: Multiply the water flow rate of the water supply channel by the water supply density of the water supply channel to obtain the first multiplication result; Subtracting the circulating flow rate in the steam generator from the value 1 yields the first subtraction result; Multiply the first subtraction result, the water flow rate of the water supply channel, and the saturated water density to obtain the second multiplication result; Add the first multiplication result to the second multiplication result to obtain the first sum result; Multiply the circulating flow rate by the water supply flow rate of the water supply channel to obtain the third multiplication result; Divide the first summation result by the third multiplication result to obtain the feedwater density in the feedwater downflow channel of the steam generator.

6. The method for determining the water level in a steam generator according to claim 2, characterized in that, Before determining the water level in the steam generator based on the feedwater density in the feedwater downflow channel, the method further includes: The following information is obtained: the first vertical height between the first contact port and the second contact port between the pressure channel of the steam generator and the body of the steam generator; the water pressure difference and water density in the pressure channel; and the second vertical height between the first contact port and the top of the steam generator, wherein the horizontal height of the first contact port is lower than the horizontal height of the second contact port. The saturated steam density of the steam generator in a saturated state is determined based on the steam temperature or the steam pressure. The step of determining the water level in the steam generator based on the feedwater density in the feedwater downflow channel includes: The water level in the steam generator is determined based on the water pressure difference in the pressure channel, the water density in the pressure channel, the gravitational acceleration, the saturated steam density, the first vertical height, the second vertical height, and the feedwater density in the feedwater descending channel of the steam generator.

7. The method for determining the water level in a steam generator according to claim 6, characterized in that, The step of determining the water level in the steam generator based on the water pressure difference in the pressure-inducing channel, the water density in the pressure-inducing channel, the gravitational acceleration, the saturated steam density, the first vertical height, the second vertical height, and the feedwater density in the feedwater descending channel of the steam generator includes: Multiply the water density in the pressure channel, the gravitational acceleration, and the first vertical height to obtain the fourth multiplication result; Multiplying the saturated vapor density, the gravitational acceleration, and the second vertical height yields the fifth multiplication result; Subtract the result of multiplying the water pressure difference in the pressure channel with the fourth result to obtain the second subtraction result; Add the second subtraction result to the fifth multiplication result to obtain the second addition result; Subtracting the saturated steam density from the water level in the steam generator yields the third subtraction result; Multiplying the third subtraction result by the gravitational acceleration yields the sixth multiplication result; Divide the second sum by the sixth multiplication result to obtain the water level in the steam generator.

8. The method for determining the water level in a steam generator according to claim 2, characterized in that, Temperature and pressure sensors are installed in the steam outlet channel to collect the steam temperature and pressure of the steam outlet channel.

9. The method for determining the water level in a steam generator according to claim 3, characterized in that, Temperature and pressure sensors are installed in the water supply channel to collect the water supply temperature and pressure of the water supply channel.

10. A device for determining the water level in a steam generator, characterized in that, The device includes: A water supply parameter acquisition module is used to acquire the water supply parameters of the steam generator, wherein the water supply parameters are parameters measured in the water supply channel connected to the steam generator; A steam parameter acquisition module is used to acquire the steam parameters of the steam generator, wherein the steam parameters are parameters measured in the steam outlet channel of the steam generator. The processing module is used to determine the feedwater density in the feedwater downflow channel of the steam generator based on the feedwater parameters and the steam parameters, and to determine the water level height in the steam generator based on the feedwater density in the feedwater downflow channel.

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