Nuclear power plant heat supply method and system

Abstract

The present application relates to a kind of nuclear power plant heating method, comprising the following steps: obtaining the actual demand amount of steam of all time in multiple user cycles, and calculating the actual demand total amount of steam of each time of all users;According to the actual demand total amount of steam, determine the predicted demand total amount of steam of all time in all user cycles;The opening of heating steam regulating valve t time is calculated, and opening control instruction is sent to heating steam regulating valve.The actual demand total amount of steam of each time of multiple users is obtained in advance, then the predicted demand total amount of steam of all time in all user cycles is determined according to the actual demand total amount of steam, and then the opening of heating steam regulating valve is calculated and adjusted according to the predicted demand total amount of steam, the opening of heating steam regulating valve is adjusted according to user demand at each time, more close to the actual demand of user, effectively reduce the waste of energy, ensure the stability and reliability of system.The present application also relates to a kind of nuclear power plant heating system.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant heating technology, and in particular to a nuclear power plant heating method and system. Background Technology

[0002] A nuclear power integrated heating system uses the main steam from the secondary loop of a nuclear power unit as a heat source, and generates heating steam through multiple heat exchange stages before delivering it to users. However, due to significant fluctuations in user-end heat demand, stable control of the heating steam pressure is crucial for the stable operation of the entire system.

[0003] Currently, domestic nuclear power integrated heating systems use a method of controlling the steam header pressure to a fixed value. This means that when the steam header pressure falls below this fixed value, the amount of steam supplied to the steam header increases. However, because the steam demand from users varies considerably, this method ignores these changes and creates a fixed pressure fluctuation. This forces the heating system to increase the supply of steam to ensure stability, with excess steam being throttled through branch steam control valves at the user ends, resulting in energy waste. Summary of the Invention

[0004] Therefore, it is necessary to address the energy waste caused by the existing nuclear power integrated heating system's method of controlling the heating main pipe pressure to a fixed value, and to provide a nuclear power plant heating method and system that can adapt to the user's needs and avoid energy waste.

[0005] A method for heating a nuclear power plant, comprising the following steps:

[0006] Obtain the actual steam demand at all times within multiple user cycles, and calculate the total actual steam demand of all users at each time.

[0007] The total predicted steam demand for all times within all user cycles is determined based on the total actual steam demand.

[0008] The opening degree of the heating steam regulating valve at time t is calculated using formula (1), and the opening degree control command is sent to the heating steam regulating valve.

[0009] POS R =F P t POS D / Fs max (1)

[0010] Among them, POS R For the opening degree of the heating steam regulating valve, F P t For the total predicted steam demand of all users at time t, POS DFs is the opening degree of the heating steam regulating valve when the total actual steam demand of all users is maximized. max This represents the maximum actual total steam demand of all users.

[0011] By adopting the above-mentioned nuclear power plant heating method, the total actual steam demand of multiple users at each moment is obtained in advance. Then, based on the total actual steam demand, the total predicted steam demand of all users at all moments within the cycle is determined. Next, the opening of the heating steam regulating valve is calculated and adjusted based on the total predicted steam demand. This allows the opening of the heating steam regulating valve to be adjusted according to user demand at each moment, which is closer to the actual needs of users, effectively reduces energy waste, and ensures the stability and reliability of the system.

[0012] In one embodiment, the nuclear power plant heating method further includes the step of:

[0013] Obtain the actual steam demand of all users for m consecutive time periods, and calculate the total actual steam demand of all users for each of the m time periods.

[0014] The total predicted steam demand is corrected using formula (2);

[0015]

[0016] Among them, F Ptx For the corrected total steam forecast demand of all users at time t, SF m F represents the total actual steam demand of all users at time m. pm The total predicted steam demand for all users at time m.

[0017] In one embodiment, the nuclear power plant heating method further includes the step of:

[0018] Obtain the actual total steam supply at time t, and calculate the supply-demand difference between the actual total steam supply and the predicted total steam demand of all users;

[0019] The opening control command is adjusted according to the magnitude of the supply-demand difference.

[0020] In one embodiment, the step of adjusting the opening control command according to the magnitude of the supply-demand difference is further included:

[0021] The first control result is obtained based on the supply-demand difference;

[0022] Multiply the first control result by a coefficient k1 and then combine it with the opening control command.

[0023] In one embodiment, the nuclear power plant heating method further includes the step of:

[0024] Obtain the actual total amount of steam supplied and calculate the heating throttling coefficient using formula (3);

[0025] The opening control command is adjusted according to the heating throttling coefficient and the actual total steam supply.

[0026] Wherein, when the heating throttling coefficient is greater than the preset coefficient value, and the actual total steam supply at time t is greater than the preset flow rate value, the opening control command is multiplied by a coefficient k2 less than 1.

[0027] Among them, formula (3) is K = (F st -SF t ) / F st K is the heating throttling coefficient, F s Let SF be the actual total amount of steam supplied at time t. t This represents the total actual steam demand of all users at time t.

[0028] In one embodiment, the nuclear power plant heating method further includes the step of:

[0029] When the pressure of the heating steam main pipe is not lower than the preset pressure value, the opening degree of the heating steam regulating valve at time t is calculated by formula (1), and the opening degree control command is sent to the heating steam regulating valve.

[0030] When the pressure of the heating steam header is lower than the preset pressure value, the actual pressure value of the heating steam header is obtained in real time, the actual pressure value is compared with the preset pressure value, and the opening of the heating steam regulating valve is adjusted in real time according to the comparison result.

[0031] In one embodiment, when the liquid level in the steam generator is lower than a preset liquid level value, the opening control command sent to the heating steam regulating valve is multiplied by a coefficient k3 less than 1.

[0032] A nuclear power plant heating system, comprising:

[0033] The main heating pipeline is connected at one end to the pressurized water reactor nuclear island.

[0034] An intermediate component, connected to the end of the main heating pipeline away from the pressurized water reactor core island, is used to convert steam into superheated steam.

[0035] A heating steam regulating valve is installed on the main heating pipeline and is used to regulate the steam supply of the main heating pipeline.

[0036] Multiple branch pipes are connected to the intermediate component simultaneously;

[0037] Multiple branch flow detectors, each branch flow detector being disposed on a corresponding branch pipe, for detecting superheated steam flowing through the branch pipe; and

[0038] The control mechanism is electrically connected to the heating steam regulating valve and each of the branch flow detectors.

[0039] In one embodiment, the nuclear power plant heating system further includes a heating steam header and a header flow detector. The heating steam header is connected between the intermediate component and the multiple branch pipes. The header flow detector is installed on the heating steam header to detect the flow rate of superheated steam flowing through the heating steam header.

[0040] In one embodiment, the nuclear power plant heating system further includes a main pipe pressure detector, which is installed on the heating steam main pipe and is used to detect the pressure of the heating steam main pipe. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of a nuclear power plant heating system according to an embodiment of the present invention;

[0043] Figure 2 A schematic diagram of the control principle of the control mechanism is provided for one embodiment of the present invention;

[0044] Figure 3 A flowchart illustrating the steps of a nuclear power plant heating method according to another embodiment of the present invention;

[0045] Figure 4 for Figure 3 The flowchart shown represents another step in the nuclear power plant heating method.

[0046] Figure 5 for Figure 3 The flowchart shown represents another step in the nuclear power plant heating method.

[0047] Labeling Explanation: 100. Nuclear Power Plant Heating System; 11. Main Heating Pipeline; 12. Heating Steam Regulating Valve; 20. Intermediate Components; 21. Steam Generator; 22. Superheater; 23. Liquid Level Detector; 31. Branch Pipeline; 32. Branch Flow Detector; 33. Branch Steam Regulating Valve; 41. Pressurized Water Reactor Island; 42. Main Power Generation Pipeline; 43. Power Generation Steam Regulating Valve; 44. Steam Turbine; 45. High-Temperature Gas-Cooled Reactor Island; 51. Deaerator; 52. Feedwater Pump; 53. Feedwater Heater; 61. Heating Steam Main Pipeline; 62. Main Pipeline Flow Detector; 63. Main Pipeline Pressure Detector;

[0048] 200. Control mechanism; 201. Function calculator; 210. First calculation unit; 211. Deviation calculator; 212. First divider; 213. Mean calculator; 214. First multiplier; 215. Second summer; 221. First PID controller; 222. Third summer; 223. Second multiplier; 230. Second calculation unit; 231. First greater than comparator; 232. Subtractor; 233. Second divider; 234. Second greater than comparator; 235. AND gate controller; 236. First selector; 237. Third multiplier; 241. Second PID controller; 242. Less than comparator; 243. NOT gate controller; 244. Delay controller; 245. Second selector; 251. Third selector; 252. Fourth multiplier. Detailed Implementation

[0049] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0050] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0052] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0053] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0054] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0055] like Figure 1 As shown, one embodiment of the present invention provides a nuclear power plant heating system 100, including a main heating pipeline 11, a heating steam regulating valve 12, an intermediate component 20, multiple branch pipelines 31, multiple branch flow detectors 32, and a control mechanism 200 (see [link to documentation]). Figure 2 ).

[0056] One end of the main heating pipeline 11 is connected to the pressurized water reactor core island 41. The heating steam regulating valve 12 is installed on the main heating pipeline 11 to regulate the steam supply of the main heating pipeline 11. The intermediate component 20 is connected to the end of the main heating pipeline 11 away from the pressurized water reactor core island 41 to convert the steam into superheated steam.

[0057] Multiple branch pipes 31 are simultaneously connected to the intermediate component 20 for delivering steam to multiple users. Each branch flow detector 32 is installed on a corresponding branch pipe 31 for detecting superheated steam flowing through the branch pipe 31.

[0058] The control mechanism 200 is electrically connected to the heating steam regulating valve 12 and each of the branch flow detectors 32 to obtain the detection data of all branch flow detectors 32. The control mechanism 200 can calculate the sum of the detection data of all branch flow detectors 32, that is, the total actual steam demand of all users, and then determine the total predicted steam demand based on the total actual steam demand, and adjust the opening of the heating steam regulating valve 12 based on the total predicted steam demand.

[0059] By configuring the aforementioned nuclear power plant heating system, the branch flow detector 32 can acquire the actual steam demand at all times within a user's cycle. This allows for the calculation of the total actual steam demand for all users at each moment. Based on this total actual demand, the predicted total steam demand is determined. Subsequently, the opening of the heating steam regulating valve 12 is adjusted according to the predicted total steam demand. This allows for the adjustment of the heating steam regulating valve 12's opening based on user demand at every moment, more closely aligning with actual user needs, effectively reducing energy waste, and ensuring system stability and reliability.

[0060] It should be noted that in this embodiment, "all users" refers to all users supplied with heat by the heating system, i.e., the aforementioned multiple users.

[0061] Furthermore, the aforementioned period is one day, and the interval between adjacent moments is one hour. In other embodiments, the period may also be one week or other time periods, and the interval between adjacent moments may be half an hour or other time periods; there is no limitation on this.

[0062] Based on the aforementioned total actual steam demand, the total predicted steam demand for all times within all user cycles is determined as follows:

[0063] When the actual steam demand of all users at all times within a single period is obtained, the total predicted steam demand is the total actual steam demand at those times. When the actual steam demand of all users at all times within multiple periods is obtained, the total predicted steam demand is the average of the total actual steam demand at those times.

[0064] Taking a day as the cycle and 9 o'clock as the time as an example.

[0065] When the actual steam demand of all users at all times of the day is obtained, the total actual steam demand at 9 o'clock on that day is calculated. Then the total predicted steam demand at 9 o'clock is the aforementioned total actual steam demand. When the actual steam demand of all users for two consecutive days is obtained, the total actual steam demand at 9 o'clock on both days is calculated. Then the total predicted steam demand at 9 o'clock on both days is the sum of the total actual steam demand at 9 o'clock on both days divided by 2.

[0066] In some embodiments, the heating system further includes a main power generation pipeline 42 and a power generation steam regulating valve 43. The main power generation pipeline 42 is connected between the pressurized water reactor nuclear island 41 and the steam turbine 44, and the power generation steam regulating valve 43 is located on the main power generation pipeline 42.

[0067] In some embodiments, there is a deaerator 51, a feed water pump 52, and a feed water heater 53. The feed water pump 52 is connected between the deaerator 51 and the feed water heater 53, and is used to pump water that has been deoxygenated by the deaerator 51 to the feed water heater 53. Then the feed water heater 53 heats the water and delivers it to the intermediate component 20.

[0068] In some embodiments, the intermediate component 20 includes a steam generator 21 and a superheater 22. The main heating steam pipeline is connected to the steam generator 21. The steam generator 21 is used to heat the feedwater with the steam delivered from the main heating steam pipeline to form saturated steam. The steam generator 21 is connected to the superheater 22 through a pipeline to deliver the saturated steam to the superheater 22.

[0069] The superheater 22 is connected to the high-temperature gas-cooled reactor core island 45 via a pipeline. The high-temperature gas-cooled reactor core island 45 delivers high-temperature steam to the superheater 22 to heat the saturated steam in the superheater 22 into superheated steam. The superheater 22 is also connected to multiple branch pipelines 31 to deliver the superheated steam to the multiple branch pipelines 31.

[0070] In some embodiments, the intermediate component 20 further includes a liquid level detector 23, which is disposed on the steam generator 21 and is used to detect the actual liquid level in the steam generator 21.

[0071] In some embodiments, the nuclear power plant heating system further includes a heating steam header 61, which is connected between the superheater 22 and multiple branch pipes 31 to transport the superheated steam generated by the superheater 22 to the multiple branch pipes 31.

[0072] In some embodiments, the nuclear power plant heating system further includes a main pipe flow detector 62, which is disposed on the heating steam main pipe 61 and is used to detect the flow rate of superheated steam flowing through the heating steam main pipe 61, i.e. the actual total amount of steam supplied.

[0073] In some embodiments, the nuclear power plant heating system further includes a main pipe pressure detector 63, which is disposed on the heating steam main pipe 61 and is used to detect the actual pressure value of the heating steam main pipe 61.

[0074] In some embodiments, the nuclear power plant heating system further includes multiple branch steam regulating valves 33, each branch steam regulating valve 33 being installed on a corresponding branch pipe 31 for regulating the flow rate of the branch pipe 31.

[0075] Please see Figure 2 In some embodiments, the control mechanism 200 includes a first summer (not shown), a prediction calculator (not shown), and a function calculator 201. The first summer is electrically connected to all branch flow detectors 32. The first summer can obtain the flow rate detected by each branch flow detector 32 at all times within the cycle and calculate the total actual steam demand of all users at each time.

[0076] The prediction calculator is electrically connected to the first summer. The prediction calculator can obtain the total actual steam demand of all users at each moment, and predict the total steam demand of all users at all moments in the cycle based on the total actual steam demand.

[0077] The function calculator 201 is electrically connected to both the prediction value calculator and the heating steam regulating valve 12. The function calculator 201 can obtain the total predicted steam demand of all users at each moment, and then determine the opening degree of the heating steam regulating valve 12 based on the total predicted steam demand, and send the opening degree control command to the heating steam regulating valve 12.

[0078] Specifically, the function calculator 201 calculates the opening degree of the heating steam regulating valve at time 12t using formula (1).

[0079] POS R =F P t POS D / Fs max (1)

[0080] Among them, POS R For the opening degree of the heating steam regulating valve 12, F P t For the total predicted steam demand of all users at time t, POS D The opening degree of the heating steam regulating valve 12 when the total actual steam demand of all users is at its maximum, Fsmax This represents the maximum actual total steam demand of all users.

[0081] In some embodiments, the control mechanism 200 further includes a first calculation unit 210, which is connected to the first summer, the prediction calculator, and the function calculator 201. The first calculation unit 210 is used to correct the total predicted steam demand and send the corrected total predicted steam demand to the function calculator 201.

[0082] Specifically, the first calculation unit 210 can obtain the total actual steam demand SF of all users at each of the m time points. t Then, the total steam demand forecast is corrected using formula (2).

[0083]

[0084] Among them, F Ptx F represents the total predicted steam demand for all users at time t after correction. Pt For the total predicted steam demand of all users at time t, SF m F represents the total actual steam demand of all users at time m. pm The total predicted steam demand for all users at time m.

[0085] It needs to be explained that F Pt For the total steam demand forecast for all users at time t, let m be the multiple times preceding time t. These m times can be consecutive to time t; for example, if time t is 9:00 AM, the interval between adjacent times is one hour, and the last of the preceding m times is 8:00 AM. Alternatively, the m times can be discontinuous to time t.

[0086] In addition, SF m -F pm The result is the difference between the actual total steam demand and the predicted total steam demand at time m. This difference is then divided by F. pm The difference ratio can be obtained. The sum of m ratio values ​​is obtained by summing them. Then, the sum of m ratio values ​​is divided by m to obtain the average ratio. The average ratio is multiplied by the total steam forecast demand to obtain the correction value. The correction value is added to the total steam forecast demand to obtain the corrected total steam forecast demand.

[0087] By using formula (2), the total predicted steam demand can be corrected in real time to reduce the difference between the total predicted steam demand and the actual steam demand, thereby further ensuring the accuracy of the heating system operation and ensuring the stability and reliability of the heating system.

[0088] In some embodiments, the first calculation unit 210 includes a deviation calculator 211, a first divider 212, a mean calculator 213, a first multiplier 214, and a second summer 215.

[0089] The deviation calculator 211 is electrically connected to both the first summer and the prediction calculator. The deviation calculator 211 can obtain the total actual demand for steam and the total predicted demand for steam, and calculate the deviation value.

[0090] The first divider 212 is electrically connected to both the deviation calculator 211 and the prediction calculator. The first divider 212 can obtain the total predicted steam demand and the deviation value calculated by the deviation calculator 211, and calculate the deviation ratio.

[0091] The mean calculator 213 is electrically connected to the first divider 212. The mean calculator 213 can continuously obtain the deviation ratios calculated by the first divider 212 for m consecutive times, that is, the deviation ratios calculated by the first divider 212 for m consecutive times. The mean calculator 213 can also calculate the mean of the deviation ratios.

[0092] The first multiplier 214 is electrically connected to the mean calculator 213, the prediction calculator and the second summer 215. The first multiplier 214 can obtain the total predicted steam demand and the average of the deviation ratio, and multiply the two to obtain the correction value.

[0093] The second summer 215 is electrically connected to the first multiplier 214, the prediction calculator, and the function calculator 201. The second summer 215 can obtain the total predicted steam demand and the correction value, and add the two to obtain the corrected total predicted steam demand. The second summer 215 is also used to send the corrected total predicted steam demand to the function calculator 201.

[0094] In some embodiments, the control mechanism 200 further includes a first PID (Proportional, Integral and Derivative) controller 221 and a third summer 222. The first PID controller 221 is electrically connected to the main pipe flow detector 62, the prediction calculator and the third summer 222. The first PID controller 221 can obtain the actual total steam supply and the predicted total steam demand, calculate the supply-demand difference between the two, and then output the first control result.

[0095] The third summer 222 is electrically connected to the first PID controller 221, the function calculator 201, and the heating steam regulating valve 12. The third summer 222 can obtain the first control result and the opening control command, and calculate the sum of the two to obtain a new opening control command. Then, the new opening control command is sent to the heating steam regulating valve 12.

[0096] In some embodiments, the control mechanism 200 further includes a second multiplier 223, which is connected between the first PID controller 221 and the third summer 222. The second multiplier 223 can obtain the first control result, multiply the first control result by a coefficient k1, and then send the product of the two to the third summer 222.

[0097] It should be noted that the specific value of the coefficient k1 can be adjusted according to the actual situation. By multiplying by k1, the opening control command can be further adjusted according to the actual situation, thereby improving the accuracy of the heating system.

[0098] In some embodiments, the control mechanism 200 further includes a second calculation unit 230, which is electrically connected to both the first summer and the main pipe flow detector 62. The second calculation unit 230 can obtain the total actual demand for steam and the total actual supply of steam, and calculate the heating throttling coefficient based on both.

[0099] Specifically, the second calculation unit 230 calculates the heating throttling coefficient using formula (3).

[0100] K = (F st -SF t ) / F st (3)

[0101] Where K is the heating throttling coefficient, F s Let SF be the actual total amount of steam supplied at time t. t This represents the total actual steam demand of all users at time t.

[0102] In some embodiments, the second calculation unit 230 is also electrically connected to the third summer 222, and the second calculation unit 230 can adjust the opening control command output by the third summer 222 according to the heating throttling coefficient and the actual total amount of steam supplied.

[0103] Specifically, when the heating throttling coefficient is greater than the preset coefficient value, and the actual total steam supply at time t is greater than the preset flow rate, the opening control command sent to the heating steam regulating valve 12 will be multiplied by a coefficient k2 less than 1.

[0104] It needs to be explained that when a user suddenly reduces their actual steam demand at time t, the total actual steam demand at time t will decrease, i.e., SFt. t It will decrease, therefore (F) st -SF t The increase of ) indicates that the actual total supply of steam is greater than the actual total demand for steam, and the gap between the two is widening.

[0105] When the K value is greater than the preset coefficient value, it indicates that the difference between the actual total steam supply and the actual total steam demand will result in significant energy waste. Therefore, the opening control command can be multiplied by a coefficient k2 less than 1 to reduce the actual total steam supply and minimize waste.

[0106] Of course, it should be noted that in order to avoid the actual total steam supply being too small, which would prevent the demand from being met when users suddenly increase their demand, it is necessary to ensure that the actual total steam supply is greater than the preset flow rate.

[0107] It should be further noted that the preset coefficient values ​​and preset flow rates mentioned above can be determined according to the actual situation, and there are no restrictions here.

[0108] In some embodiments, the second calculation unit 230 includes a first greater than comparator 231, a subtractor 232, a second divider 233, a second greater than comparator 234, and an AND gate controller 235.

[0109] The first comparator 231 is electrically connected to the main pipe flow detector 62 and is used to compare the actual total steam supply with the preset flow value.

[0110] The subtractor 232 is electrically connected to both the first summer and the main pipe flow detector 62. The subtractor 232 is used to calculate the difference between the actual total steam supply and the actual total steam demand.

[0111] The second divider 233 is electrically connected to both the subtractor 232 and the main pipe flow detector 62. The second divider 233 is used to calculate the ratio of the difference to the actual total amount of steam supplied, i.e. the heating throttling coefficient.

[0112] The second greater than comparator 234 is electrically connected to both the second divider 233 and the AND gate controller 235, and is used to compare the heating throttling coefficient with a preset coefficient value.

[0113] Furthermore, the second calculation unit 230 also includes a first selector 236 and a third multiplier 237. The first selector 236 is electrically connected to the third summer 222, the AND gate controller 235, the third multiplier 237, and the heating steam regulating valve 12.

[0114] When the output of AND gate controller 235 is false, the first selector 236 selects to directly output the opening control command input by the third summer 222 to the heating steam regulating valve 12.

[0115] When the heating throttling coefficient is greater than the preset coefficient value and the actual total steam supply is greater than the preset flow rate value, the gate controller 235 outputs true, the first selector 236 selects to output the opening control command input by the third summer 222 to the third multiplier 237, the third multiplier 237 is used to multiply the opening control command by a coefficient k2 less than 1 to obtain a new opening control command, and send the new opening control command to the heating steam regulating valve 12.

[0116] In some embodiments, the control mechanism 200 further includes a second PID controller 241, a less than comparator 242, a NOT gate controller 243, a delay controller 244, and a second selector 245.

[0117] The second PID controller 241 is electrically connected to the main pipe pressure detector 63.

[0118] The less-than comparator 242 is electrically connected to both the main pipe pressure detector 63 and the NOT gate controller 243. The less-than comparator 242 is used to compare the actual pressure value of the heating steam main pipe 61 with the preset pressure value.

[0119] The delay controller 244 is electrically connected to the NAND gate controller 243, and the second selector 245 is simultaneously electrically connected to the third summer 222, the delay controller 244, the second PID controller 241, and the first selector 236.

[0120] When the actual pressure value is not less than the preset pressure value, the output of the NOT gate controller 243 is true. At this time, the opening control command output by the third summer 222 is directly sent to the first selector 236.

[0121] When the actual pressure value is less than the preset pressure value, the output of the NOT gate controller 243 is false. At this time, the opening control command of the third summer 222 is no longer used. Instead, the opening of the heating steam regulating valve 12 is directly controlled by the feedback control of the second PID controller 241.

[0122] It is understandable that the delay controller 244 can transmit the output of the NOT gate controller 243 to the second selector 245 after the actual pressure value is not less than the preset pressure value for a period of time.

[0123] In some embodiments, the control mechanism 200 further includes a third selector 251 and a fourth multiplier 252. The third selector 251 is connected between the first selector 236 and the second selector 245, and the third selector 251 is also electrically connected to the liquid level detector 23.

[0124] When the actual liquid level detected by the liquid level detector 23 is not lower than the preset liquid level value, the opening control command is transmitted to the first selector 236 through the third selector 251.

[0125] When the actual liquid level is lower than the preset liquid level value, the fourth multiplier 252 receives the opening control command output by the third summer 222 and multiplies the opening control command by a coefficient k3 less than 1.

[0126] It should be noted that when the liquid level in steam generator 21 is lower than the preset value, it is a special case. In this situation, it is necessary to ensure the stability of the heating system and avoid the water pumps from tripping and the heating system from shutting down due to the low liquid level. Therefore, the stability of the heating system itself should be given priority in this case, and the actual total amount of steam supplied should be limited to alleviate the low liquid level in steam generator 21 until the liquid level returns to normal.

[0127] Similarly, the value of k3 can be set according to the actual situation. Moreover, when setting the value of k3 under this condition, the heating at the user end does not need to be considered, and the stability of the heating system should be given priority.

[0128] Please see Figures 1 to 3 An embodiment of the present invention provides a method for heating a nuclear power plant, comprising the following steps:

[0129] S110: Obtain the actual steam demand at all times within multiple user cycles, and calculate the total actual steam demand of all users at each time.

[0130] S120, based on the aforementioned total actual steam demand, determine the total predicted steam demand for all times within all user cycles.

[0131] S150, calculate the opening degree of the heating steam regulating valve 12t at time t, and send the opening degree control command to the heating steam regulating valve 12.

[0132] Specifically, the opening degree of the heating steam regulating valve at time 12t is calculated using formula (1).

[0133] POS R =F P t POS D / Fs max (1)

[0134] Among them, POS R For the opening degree of the heating steam regulating valve 12, F P t For the total predicted steam demand of all users at time t, POS D The opening degree of the heating steam regulating valve 12 when the total actual steam demand of all users is at its maximum, Fs max This represents the maximum actual total steam demand of all users.

[0135] By adopting the above-mentioned nuclear power plant heating method, the total actual steam demand of multiple users at each moment is obtained in advance. Then, based on the total actual steam demand, the total predicted steam demand of all users at all moments within the cycle is determined. Next, the opening of the heating steam regulating valve 12 is calculated and adjusted based on the total predicted steam demand. This allows the opening of the heating steam regulating valve 12 to be adjusted according to user demand at each moment, which is closer to the actual needs of users, effectively reduces energy waste, and ensures the stability and reliability of the system.

[0136] In some embodiments, the nuclear power plant heating method further includes the step of:

[0137] S130: Obtain the actual steam demand of all users for m consecutive time periods, and calculate the total actual steam demand of all users for each of the m time periods.

[0138] S140, revise the total forecasted steam demand.

[0139] Specifically, the total steam demand forecast is corrected using formula (2).

[0140]

[0141] Among them, F Ptx F represents the total predicted steam demand for all users at time t after correction. Pt For the total predicted steam demand of all users at time t, SF m F represents the total actual steam demand of all users at time m. pm The total predicted steam demand for all users at time m.

[0142] Please see Figure 4 In some embodiments, the nuclear power plant heating method further includes:

[0143] S210: Obtain the actual total steam supply at time t, and calculate the supply-demand difference between the actual total steam supply and the total predicted steam demand of all users.

[0144] S220 adjusts the opening control command according to the size of the supply-demand difference.

[0145] Furthermore, before adjusting the opening control command based on the magnitude of the supply-demand difference, the method further includes the following steps:

[0146] The first control result is obtained based on the supply-demand difference;

[0147] Specifically, by setting a PID controller, the PID controller obtains the supply-demand difference and outputs a first control result based on the supply-demand difference. The first control result is accumulated with the opening control command mentioned above to adjust the opening control command.

[0148] Multiply the first control result by a coefficient k1.

[0149] It should be noted that the specific value of the coefficient k1 can be adjusted according to the actual situation. By multiplying by k1, the opening control command can be further adjusted according to the actual situation, thereby improving the accuracy of the heating system.

[0150] Please see Figure 5 In some embodiments, the nuclear power plant heating method further includes the step of:

[0151] S310: Obtain the actual total steam supply and calculate the heating throttling coefficient.

[0152] Specifically, the heating throttling coefficient is calculated using formula (3).

[0153] K = (F st -SF t ) / F st (3)

[0154] Where K is the heating throttling coefficient, F s Let SF be the actual total amount of steam supplied at time t. t This represents the total actual steam demand of all users at time t.

[0155] S320, adjust the opening control command according to the heating throttling coefficient and the actual total steam supply.

[0156] Specifically, when the heating throttling coefficient is greater than the preset coefficient value, and the actual total steam supply at time t is greater than the preset flow rate, the opening control command sent to the heating steam regulating valve 12 will be multiplied by a coefficient k2 less than 1.

[0157] In some embodiments, when the liquid level of the steam generator 21 is lower than the preset liquid level value, the opening control command sent to the heating steam regulating valve 12 is multiplied by a coefficient k3 less than 1.

[0158] In some embodiments, the nuclear power plant heating method further includes the step of:

[0159] When the pressure of the heating steam main pipe 61 is not lower than the preset pressure value, the opening degree of the heating steam regulating valve 12t is calculated by formula (1), and the opening degree control command is sent to the heating steam regulating valve 12.

[0160] When the pressure of the heating steam header 61 is lower than the preset pressure value, the actual pressure value of the heating steam header 61 is obtained in real time, the actual pressure value is compared with the preset pressure value, and the opening of the heating steam regulating valve 12 is adjusted in real time according to the comparison result.

[0161] In this embodiment, when the pressure of the heating steam header 61 is not lower than the preset pressure value, the pressure of the heating steam header 61 can meet the requirement of outputting steam according to the total predicted steam demand in the above embodiment. Therefore, the method in the above embodiment is used to adjust the opening control command to adjust the heating steam regulating valve 12.

[0162] When the pressure of the heating steam header 61 is lower than the preset pressure value, the pressure of the heating steam header 61 cannot meet the requirement of outputting steam according to the total steam demand predicted in the above embodiment. Therefore, the actual pressure value of the heating steam header 61 is obtained for feedback adjustment.

[0163] It should be noted that the existing solution is to obtain the actual pressure value of the heating steam header 61 for feedback adjustment. In this embodiment, when the pressure value of the heating steam header 61 is lower than the preset pressure value, the priority is no longer energy waste, but ensuring the reliability of heating to users. Therefore, this solution is adopted.

[0164] In some embodiments, after the pressure of the heating steam header 61 recovers to a preset pressure value for a preset time, the control scheme is switched to control the heating supply by predicting the total demand for steam.

[0165] It should be noted that the preset time can be achieved through the on-delay controller 244.

[0166] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0167] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for heating a nuclear power plant, characterized in that, Including the following steps: Obtain the actual steam demand at all times within multiple user cycles, and calculate the total actual steam demand of all users at each time. The total predicted steam demand for all times within all user cycles is determined based on the total actual steam demand. The opening degree of the heating steam regulating valve at time t is calculated using formula (1), and the opening degree control command is sent to the heating steam regulating valve. Among them, POS R For the opening degree of the heating steam regulating valve, F Pt For the total predicted steam demand of all users at time t, POS D Fs is the opening degree of the heating steam regulating valve when the total actual steam demand of all users is maximized. max The maximum actual total steam demand of all users; The nuclear power plant heating method also includes the following steps: Obtain the actual total amount of steam supplied and calculate the heating throttling coefficient using formula (3); The opening control command is adjusted according to the heating throttling coefficient and the actual total steam supply. Wherein, when the heating throttling coefficient is greater than the preset coefficient value, and the actual total steam supply at time t is greater than the preset flow rate value, the opening control command is multiplied by a coefficient k2 less than 1. Among them, formula (3) is K = (F st -SF t ) / F st K is the heating throttling coefficient, F s Let SF be the actual total amount of steam supplied at time t. t This represents the total actual steam demand of all users at time t.

2. The nuclear power plant heating method according to claim 1, characterized in that, The nuclear power plant heating method also includes the following steps: Obtain the actual steam demand of all users for m consecutive time periods, and calculate the total actual steam demand of all users for each of the m time periods. The total predicted steam demand is corrected using formula (2); Among them, F Ptx For the corrected total steam forecast demand of all users at time t, SF m F represents the total actual steam demand of all users at time m. pm The total predicted steam demand for all users at time m.

3. The nuclear power plant heating method according to claim 2, characterized in that, The nuclear power plant heating method also includes the following steps: Obtain the actual total steam supply at time t, and calculate the supply-demand difference between the actual total steam supply and the predicted total steam demand of all users; The opening control command is adjusted according to the magnitude of the supply-demand difference.

4. The nuclear power plant heating method according to claim 3, characterized in that, Before adjusting the opening control command based on the magnitude of the supply-demand difference, the following steps are included: The first control result is obtained based on the supply-demand difference; the first control result is multiplied by a coefficient k1 and then added to the opening control command.

5. The nuclear power plant heating method according to claim 1, characterized in that, The nuclear power plant heating method also includes the following steps: When the pressure of the heating steam main pipe is not lower than the preset pressure value, the opening degree of the heating steam regulating valve at time t is calculated by formula (1), and the opening degree control command is sent to the heating steam regulating valve. When the pressure of the heating steam header is lower than the preset pressure value, the actual pressure value of the heating steam header is obtained in real time, the actual pressure value is compared with the preset pressure value, and the opening of the heating steam regulating valve is adjusted in real time according to the comparison result.

6. The nuclear power plant heating method according to claim 1, characterized in that, When the liquid level in the steam generator is lower than the preset liquid level value, the opening control command sent to the heating steam regulating valve will be multiplied by a coefficient k3 less than 1.

7. A nuclear power plant heating system, characterized in that, The nuclear power plant heating system is used to implement the nuclear power plant heating method according to any one of claims 1 to 6, and the nuclear power plant heating system includes: The main heating pipeline is connected at one end to the pressurized water reactor nuclear island. An intermediate component, connected to the end of the main heating pipeline away from the pressurized water reactor core island, is used to convert steam into superheated steam. A heating steam regulating valve is installed on the main heating pipeline and is used to regulate the steam supply of the main heating pipeline. Multiple branch pipes are connected to the intermediate component simultaneously; Multiple branch flow detectors, each of which is installed on a corresponding branch pipe, are used to detect superheated steam flowing through the branch pipe; The control mechanism is electrically connected to the heating steam regulating valve and each of the branch flow detectors.

8. The nuclear power plant heating system according to claim 7, characterized in that, The nuclear power plant heating system also includes a heating steam header and a header flow detector. The heating steam header is connected between the intermediate component and the multiple branch pipes. The header flow detector is installed on the heating steam header to detect the flow rate of superheated steam flowing through the heating steam header.

9. The nuclear power plant heating system according to claim 8, characterized in that, The nuclear power plant heating system also includes a main pipe pressure detector, which is installed on the heating steam main pipe and is used to detect the pressure of the heating steam main pipe.

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