High-low pressure bypass heat supply reheat steam flow rate monitoring device, control method and apparatus

Abstract

The application provides a high-low pressure bypass heat supply reheating steam flow rate monitoring device, a control method and an apparatus, comprising: a CPU processor, a boiler, a high pressure cylinder, a medium pressure cylinder, a first heat network heater and a second heat network heater; the input interface of the CPU processor is in communication connection with the pipeline in the high-low pressure bypass heat supply system, and is used for collecting steam data from the pipeline. The application realizes real-time dynamic monitoring of the high-low pressure bypass heat supply unit heat section reheating steam flow rate. When the flow rate is too high, an alarm can be sent and corresponding measures can be taken through an automatic control scheme, the reheating steam flow rate is timely controlled to a reasonable range, the steam flow rate is prevented from being too fast to cause scouring damage to the pipeline and equipment and affect the safe operation of the unit, automatic monitoring and automatic control of the reheating steam flow rate are realized, the workload of the operation personnel is reduced, errors caused by manual operation are reduced, and the safety and stability of long-time operation of the high-low pressure bypass heat supply unit are ensured.

Description

Technical Field

[0001] This application belongs to the field of heating system renovation technology, specifically, it relates to a high and low pressure bypass heating reheat steam flow rate monitoring device, control method and apparatus. Background Technology

[0002] While wind and solar power provide a significant amount of clean electricity, the randomness and instability of their power generation pose substantial challenges to the safe operation of the power system and the guarantee of power supply. Consequently, some regions have experienced severe curtailment of wind, solar, and hydropower. To address these issues, it is necessary to tap the peak-shaving potential of thermal power units, improve their operational flexibility, and enhance the absorption capacity of new energy sources. For combined heat and power (CHP) units in northern China, the peak-shaving capacity is even worse due to limitations imposed by heat load. Currently, an increasing number of CHP plants are undertaking high- and low-voltage bypass heating system upgrades to lower the lower limit of peak-shaving capacity during the heating season, thereby improving their competitiveness and profitability in the electricity market.

[0003] For the renovation of high and low pressure bypass heating systems, a typical renovation scheme is as follows: The existing high-pressure bypass valve is modified, retaining its original start-up and shutdown functions; a new low-pressure bypass desuperheating and pressure-reducing valve is added, arranged in parallel with the original low-pressure bypass. The new low-pressure bypass valve only needs to meet the needs of the unit's deep peak-shaving heating operation. Both the new low-pressure bypass valve and the modified high-pressure bypass valve have the capability for long-term continuous and stable bypass valve heating. After the unit undergoes high and low pressure bypass heating renovation, because a portion of the reheat steam in the hot section goes to the heating network heater through the new low-pressure bypass valve, the reheat steam flow rate in the hot section will increase under the same electrical load. Simultaneously, its velocity will also increase. Excessive steam velocity can cause erosion damage to pipelines and equipment, accompanied by abnormal noise, affecting the safe operation of the unit. In general, due to the large diameter of the hot section reheat steam pipeline, the steam flow rate and velocity are difficult to measure directly, so there are usually no corresponding measuring points. In addition, the flow velocity of the hot section reheat steam pipeline of the original unit has been checked in the design stage. Therefore, power plant operators often do not pay enough attention to the parameter of hot section reheat steam flow velocity. Over time, this will have a huge impact on the safe operation and service life of units that have undergone high and low pressure bypass heating retrofit. Summary of the Invention

[0004] This application provides a high and low pressure bypass heating reheat steam flow rate monitoring device, control method and apparatus to at least solve the problem that the current hot section reheat steam pipeline has a large diameter, making it difficult to directly measure the steam flow rate and velocity. Over time, this will have a huge impact on the safe operation and service life of units that have undergone high and low pressure bypass heating retrofit.

[0005] According to the first aspect of this application, a high and low pressure bypass heating reheat steam flow rate monitoring device is provided, comprising: a CPU processor, a boiler, a high pressure cylinder, a medium pressure cylinder, a first heating network heater and a second heating network heater.

[0006] The boiler is connected to the high-pressure cylinder through a first main pipe; the first main pipe branches off into a first side pipe branch, which connects the first main pipe to the exhaust pipe of the high-pressure cylinder.

[0007] The boiler is connected to the intermediate pressure cylinder through the second main pipe; the second main pipe branches off into a second side pipe branch, which is connected to the exhaust pipe of the intermediate pressure cylinder.

[0008] The exhaust pipe of the intermediate pressure cylinder is connected to the first heating network heater and the second heating network heater respectively;

[0009] The CPU processor's input interface is connected to the pipelines in the high and low pressure bypass heating system to collect steam data from the pipelines.

[0010] In one embodiment, a high-pressure main steam valve is provided at the connection between the first main pipeline and the high-pressure cylinder, and a high-pressure bypass valve is provided on the first side pipeline branch.

[0011] In one specific embodiment, a medium-pressure combined steam valve is provided at the connection between the second main pipeline and the medium-pressure cylinder, and an additional low-pressure bypass valve is provided at the connection between the second bypass branch and the exhaust pipeline of the medium-pressure cylinder.

[0012] In one specific embodiment, a control valve is respectively installed at the inlet of the first heating network heater and the second heating network heater.

[0013] According to a second aspect of this application, a method for monitoring the reheat steam velocity in high and low pressure bypass heating is also provided, comprising:

[0014] Collect relevant thermal data of the high and low pressure bypass heating system under the current operating conditions;

[0015] Determine the parameters required for calculating the reheat steam velocity in the hot section based on relevant thermodynamic data;

[0016] The steam mass flow rate of reheat steam entering the intermediate pressure cylinder in the hot section is obtained based on the Flügler formula and relevant thermodynamic data.

[0017] The steam mass flow rate of hot section reheat steam passing through the new low bypass valve is calculated based on the flow characteristic function of the new low bypass valve.

[0018] The reheat steam velocity in the hot section is determined based on the mass flow rate of the hot section reheat steam and relevant thermodynamic data.

[0019] In one embodiment, determining the parameters required for calculating the reheat steam velocity in the hot section based on relevant thermodynamic data includes:

[0020] Calculate macros using the properties of water and water vapor;

[0021] The specific volume of the hot-section reheat steam is determined based on the pressure and temperature of the hot-section reheat steam in the relevant thermal data.

[0022] In one embodiment, the steam mass flow rate of the hot-section reheat steam entering the intermediate-pressure cylinder is obtained according to the Flügger formula and related thermodynamic data, including:

[0023] The Flügler formula is applied to calculate the steam mass flow rate of reheat steam entering the intermediate pressure cylinder from the steam pressure after the intermediate pressure combined steam valve and the extraction steam pressure of the fourth stage of the intermediate pressure cylinder in the relevant thermodynamic data.

[0024] In one embodiment, calculating the steam mass flow rate of hot-section reheat steam through the newly added low bypass valve based on the flow characteristic function of the newly added low bypass valve includes:

[0025] The steam mass flow rate of the reheat steam in the hot section through the new low-pressure bypass valve is calculated by applying the flow characteristic function of the new low-pressure bypass valve and the steam differential pressure before and after the new low-pressure bypass valve and the valve opening of the new low-pressure bypass valve in the relevant thermodynamic data.

[0026] In one embodiment, determining the hot-section reheat steam velocity based on the hot-section reheat steam mass flow rate and the relevant thermodynamic data includes:

[0027] The mass flow rate of the hot section reheat steam is determined by summing the mass flow rate of the hot section reheat steam entering the intermediate pressure cylinder and the mass flow rate of the hot section reheat steam passing through the newly added low bypass valve. The flow velocity of the hot section reheat steam is then determined by combining the specific volume of the hot section reheat steam and the inner diameter of the hot section reheat steam pipeline.

[0028] According to a third aspect of this application, a high- and low-pressure bypass heating reheat steam flow rate monitoring device is also provided, comprising:

[0029] The thermal data acquisition unit is used to collect relevant thermal data of the high and low pressure bypass heating system in real time under the current operating conditions;

[0030] The parameter calculation unit is used to determine the parameters required for calculating the reheat steam flow rate in the hot section based on relevant thermodynamic data.

[0031] The steam mass flow unit is used to obtain the steam mass flow rate of hot section reheat steam entering the intermediate pressure cylinder and passing through the newly added low bypass valve, based on the Fliuger formula, the valve flow characteristic function of the newly added low bypass valve, and relevant thermodynamic data.

[0032] The reheat steam velocity unit is used to determine the reheat steam velocity in the hot section based on the reheat steam mass flow rate in the hot section and related thermodynamic data.

[0033] In one embodiment, the parameter calculation unit includes:

[0034] Application module, used for macros that calculate the properties of water and water vapor;

[0035] The specific volume calculation module is used to determine the specific volume of the hot section reheat steam based on the pressure and temperature of the hot section reheat steam in the relevant thermodynamic data.

[0036] In one embodiment, the steam mass flow unit includes:

[0037] The steam mass flow calculation module is used to calculate the steam mass flow rate of hot section reheat steam entering the intermediate pressure cylinder by applying the Flügger formula and the steam pressure after the intermediate pressure combined steam valve and the extraction steam pressure of the four sections of the intermediate pressure cylinder in the relevant thermodynamic data; and to calculate the steam mass flow rate of hot section reheat steam passing through the newly added low-pressure bypass valve by applying the flow characteristic function of the newly added low-pressure bypass valve and the steam differential pressure before and after the newly added low-pressure bypass valve and the valve opening of the newly added low-pressure bypass valve in the relevant thermodynamic data.

[0038] In one embodiment, the reheat steam flow rate unit includes:

[0039] The reheat steam velocity calculation module is used to determine the hot section reheat steam mass flow rate based on the sum of the steam mass flow rate of the reheat steam entering the intermediate pressure cylinder and the steam mass flow rate of the hot section reheat steam passing through the newly added low bypass valve. Then, it combines the hot section reheat steam specific volume and the hot section reheat steam pipeline inner diameter to determine the hot section reheat steam velocity. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A schematic diagram of a high and low pressure bypass heating reheat steam flow rate monitoring device provided in this application.

[0042] Figure 2 A flowchart of a method for monitoring the reheat steam velocity in high and low pressure bypass heating provided in this application.

[0043] Figure 3 This is a flowchart illustrating the parameters required for calculating the reheat steam flow rate in the hot section based on relevant thermodynamic data, as described in this application embodiment.

[0044] Figure 4 This is a block diagram of the hot section reheat steam flow rate monitoring device in the embodiments of this application.

[0045] Figure 5 The structural block diagram of a high and low pressure bypass heating reheat steam flow rate monitoring device provided in this application.

[0046] Figure 6 This is a structural block diagram of the parameter calculation unit in an embodiment of this application.

[0047] Figure 7 This is a specific implementation of an electronic device in the embodiments of this application. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] To address the problems existing in the background technology, this application provides a high and low pressure bypass heating reheat steam flow rate monitoring device, control method, and apparatus. The method calculates the steam inlet volume of the intermediate pressure cylinder using the Früger formula in the control processor, calculates the new low pressure bypass steam flow rate based on the flow characteristic function of the new low pressure bypass valve, and adds the two to obtain the hot section reheat steam mass flow rate. Then, the hot section reheat steam flow rate is obtained through the hot section reheat steam pipe diameter and current steam-related thermodynamic parameters, and is monitored in real time. When the flow rate is too high, an alarm is issued and corresponding measures are taken, achieving real-time monitoring and automatic control of the hot section reheat steam flow rate to ensure the safety and stability of the high and low pressure bypass heating unit during long-term operation.

[0050] This application provides a high and low pressure bypass heating reheat steam flow rate monitoring device, comprising:

[0051] A CPU processor, a boiler, a high-pressure cylinder, a medium-pressure cylinder, a first heating network heater, and a second heating network heater;

[0052] The boiler is connected to the high-pressure cylinder through a first main pipe; the first main pipe branches off into a first side pipe branch, which connects the first main pipe to the exhaust pipe of the high-pressure cylinder.

[0053] The boiler is connected to the intermediate pressure cylinder through the second main pipe; the second main pipe branches off into a second side pipe branch, which is connected to the exhaust pipe of the intermediate pressure cylinder.

[0054] The exhaust pipe of the intermediate pressure cylinder is connected to the first heating network heater and the second heating network heater respectively;

[0055] The CPU processor's input interface is connected to the pipelines in the high and low pressure bypass heating system to collect steam data from the pipelines.

[0056] In one embodiment, a high-pressure main steam valve is provided at the connection between the first main pipeline and the high-pressure cylinder, and a high-pressure bypass valve is provided on the first side pipeline branch.

[0057] In one embodiment, a medium-pressure combined steam valve is provided at the connection between the second main pipeline and the medium-pressure cylinder, and an additional low-pressure bypass valve is provided at the connection between the second bypass branch and the exhaust pipeline of the medium-pressure cylinder.

[0058] In one embodiment, a control valve is provided at the inlet of the first heating network heater and the second heating network heater, respectively.

[0059] In one specific embodiment, such as Figure 1 As shown, the high and low pressure bypass heating system and reheat steam flow rate monitoring equipment include a control processor 1, a boiler 2, a high pressure cylinder 3, a medium pressure cylinder 4, a high pressure main steam valve 5, a medium pressure combined steam valve 6, a high pressure bypass valve 7, a newly added low pressure bypass valve 8, first and second heating network heaters 9 and 10, and corresponding control valves, etc.

[0060] In a typical high-low pressure bypass heating system, feedwater is heated in boiler 2 to become superheated steam, i.e., turbine main steam. This main steam is divided into two paths: one path connects to the turbine high-pressure cylinder 3 via high-pressure main steam valve 5, and the other path connects to the high-pressure cylinder exhaust pipe via high-pressure bypass valve 7. After performing work in the turbine high-pressure cylinder, the superheated steam is discharged through the high-pressure cylinder exhaust port. It then merges with the steam that has been depressurized by the high-pressure bypass valve and enters the boiler cold-end reheat steam inlet. The steam is then reheated in the boiler to become hot-section reheat steam. This hot-section reheat steam is also divided into two paths: one path enters the turbine intermediate-pressure cylinder via intermediate-pressure combined steam valve 6, and the other path connects to the intermediate-pressure cylinder exhaust pipe via a newly added low-pressure bypass valve 8. After performing work in the intermediate-pressure cylinder, the superheated steam has three destinations: 1. Part of the steam that has performed some work in the intermediate-pressure cylinder is extracted through the fourth extraction port and goes to No. 4. In the regenerative heater, part of the steam from the exhaust of the intermediate-pressure cylinder 2 is sent to the first and second heating network heaters through two steam pipelines. The remaining steam from the exhaust of the intermediate-pressure cylinder 3 is sent to the low-pressure cylinder through a pipeline to continue doing work. The steam after being de-heated and depressurized by the newly added low-pressure bypass valve 8 is divided into two paths, which are then combined with the two intermediate-pressure cylinder exhausts that are going to the heating network heaters and sent to the first and second heating network heaters. The steam pipelines of the first heating network heater 9 and the second heating network heater 10 are also equipped with a first control valve 11 and a second control valve 12, respectively. The steam that has released heat in the first and second heating network heaters condenses into condensate and is then sent to the condensate cooler. The first and second heating network heaters are arranged in parallel, that is, the return water of the heating network is divided into two paths and enters the first and second heating network heaters. After being heated and raised in temperature, the water is combined again at the outlet and sent to the heat users for heating.

[0061] According to a second aspect of this application, based on the aforementioned monitoring equipment, a method for monitoring the flow rate of high and low pressure bypass heating reheat steam is incorporated into the CPU processor, such as... Figure 2 As shown, it includes:

[0062] S301: Collects real-time relevant thermal data of the high and low pressure bypass heating system under current operating conditions.

[0063] S302: Determine the parameters required for calculating the reheat steam velocity in the hot section based on relevant thermodynamic data.

[0064] S303: The steam mass flow rate of reheat steam entering the intermediate pressure cylinder in the hot section is obtained based on the Freuger formula and relevant thermodynamic data.

[0065] S304: Calculate the steam mass flow rate of hot section reheat steam through the new low bypass valve based on the flow characteristic function of the new low bypass valve.

[0066] S305: Determine the reheat steam velocity in the hot section based on the hot section reheat steam mass flow rate and relevant thermodynamic data.

[0067] In one embodiment, the parameters required for calculating the reheat steam flow rate in the hot section are determined based on relevant thermodynamic data, such as... Figure 3 As shown, it includes:

[0068] S401: Calculation macro using the properties of water and water vapor.

[0069] S402: Determine the specific volume of the hot section reheat steam based on the pressure and temperature of the hot section reheat steam in the relevant thermodynamic data.

[0070] In one embodiment, the steam mass flow rate of the hot-section reheat steam entering the intermediate-pressure cylinder is obtained according to the Flügger formula and related thermodynamic data, including:

[0071] The Flügler formula is applied to calculate the steam mass flow rate of reheat steam entering the intermediate pressure cylinder from the steam pressure after the intermediate pressure combined steam valve and the extraction steam pressure of the fourth stage of the intermediate pressure cylinder in the relevant thermodynamic data.

[0072] In one embodiment, calculating the steam mass flow rate of hot-section reheat steam through the newly added low bypass valve based on the flow characteristic function of the newly added low bypass valve includes:

[0073] The steam mass flow rate of the reheat steam in the hot section through the new low-pressure bypass valve is calculated by applying the flow characteristic function of the new low-pressure bypass valve and the steam differential pressure before and after the new low-pressure bypass valve and the valve opening of the new low-pressure bypass valve in the relevant thermodynamic data.

[0074] In one embodiment, determining the hot-section reheat steam velocity based on the hot-section reheat steam mass flow rate and the relevant thermodynamic data includes:

[0075] The mass flow rate of the hot section reheat steam is determined by summing the mass flow rate of the hot section reheat steam entering the intermediate pressure cylinder and the mass flow rate of the hot section reheat steam passing through the newly added low bypass valve. The flow velocity of the hot section reheat steam is then determined by combining the specific volume of the hot section reheat steam and the inner diameter of the hot section reheat steam pipeline.

[0076] In one embodiment, such as Figure 4 As shown, the hot section reheat steam flow rate monitoring device includes a data acquisition module, a parameter confirmation module, a flow rate calculation module, a flow rate calculation module, and a flow rate display module. Its working process is as follows:

[0077] The data acquisition module 21 collects real-time relevant thermal data under the current operating conditions of the high and low pressure bypass heating, including: hot section reheat steam pressure p. rh Temperature t rh Steam pressure p1 and temperature t1 after the intermediate-pressure combined steam valve; steam pressure p2 and temperature t2 of the fourth stage extraction steam of the intermediate-pressure cylinder; steam differential pressure Δp before and after the newly added low-pressure bypass valve. d The newly added low-pressure bypass valve has an opening degree k. d d, the inner diameter of the hot section reheat steam pipe.

[0078] The parameter determination module 22 uses the properties of water and steam to calculate a macro, based on the reheat steam pressure p in the hot section. rh Temperature t rh Determine the specific volume v of the reheat steam in the hot section, i.e., v = f(p rh ,t rh This prepares for the calculation of reheat steam velocity in the hot section.

[0079] Using the flow calculation module 23, the Früger formula is applied to calculate the steam mass flow rate G1 of the hot section reheat steam entering the intermediate pressure cylinder. The calculation formula is as follows:

[0080]

[0081] Wherein, G1 is the mass flow rate of reheat steam entering the intermediate pressure cylinder in the hot section, t / h;

[0082] λ is the Fruggle coefficient, which is a constant, and is taken as 5546.646 here;

[0083] p1 is the steam pressure after the intermediate-pressure combined steam valve, in MPa;

[0084] t1 is the steam temperature after the intermediate-pressure combined steam valve, in °C;

[0085] p2 is the extraction pressure of the fourth stage of the intermediate pressure cylinder, in MPa.

[0086] Based on the flow characteristics of the newly added low-pressure bypass valve, the steam mass flow rate G2 of the hot section reheat steam passing through the newly added low-pressure bypass valve is calculated. The calculation formula is as follows:

[0087] G2 = 3.6·α·Δp d ·F(k d )

[0088] Wherein, G2 is the steam mass flow rate (t / h) of the hot section reheat steam flowing through the newly added low-pressure bypass valve;

[0089] α represents the flow coefficient of the newly added low-pressure bypass valve, provided in the manufacturer's instruction manual;

[0090] Δp d The steam differential pressure before and after the newly added low-pressure bypass valve is measured in MPa.

[0091] k d To adjust the opening degree of the newly added low-pressure bypass valve, %;

[0092] F(k d The function for the valve opening and flow rate curve of the newly added low-pressure bypass valve is provided in the manufacturer's manual.

[0093] Using the velocity calculation module 24, and applying relevant fluid mechanics theories, the reheat steam velocity v in the hot section is calculated. rh The calculation formula is as follows:

[0094]

[0095] Wherein, G1 is the mass flow rate of reheat steam entering the intermediate pressure cylinder in the hot section, t / h;

[0096] G2 is the steam mass flow rate (t / h) of the hot section reheat steam flowing through the newly added low-pressure bypass valve;

[0097] v is the specific volume of reheated steam in the hot section, m 3 / kg;

[0098] π is the mathematical constant for a circle, and it is an infinite non-repeating decimal.

[0099] d is the inner diameter of the hot section reheat steam pipe, in meters.

[0100] The current flow rate of reheat steam in the hot section is displayed on the DCS "Heating Network System" screen of the operator via the flow rate display module 25, so as to facilitate real-time monitoring by the operator.

[0101] It should be noted that the operating status of the high and low pressure bypass heating system is constantly changing. The sampling period of the data acquisition module in the flow monitoring device of the present invention is 200ms, that is, the relevant thermal data of the high and low pressure bypass heating is collected once every 200ms. Then, the subsequent modules are used to calculate and display the current new hot section reheat steam flow rate, so as to ensure the real-time performance of the hot section reheat steam flow rate.

[0102] Units undergoing high- and low-pressure bypass heating system retrofits are primarily designed to meet the peak-shaving demands of the power grid during the winter heating season. Therefore, during this period, these units need to gradually reduce their electrical load while ensuring adequate heat load. However, as the electrical load decreases and the heat load increases, the reheat steam velocity in the hot section gradually rises. Excessive steam velocity can cause erosion damage to pipes and equipment, accompanied by abnormal noise, affecting the safe operation of the unit. This necessitates dedicated operators to monitor and adjust the reheat steam velocity promptly, significantly increasing their workload and inevitably increasing the risk of human error.

[0103] Therefore, while enabling real-time monitoring of the reheat steam flow rate in the hot section, this invention also relates to an automatic control method for reheat steam flow rate applicable to high and low pressure bypass heating. This method can automatically control the reheat steam flow rate and prevent excessively high reheat steam flow rate from affecting the safe operation of the unit. This method controls the reheat steam velocity in three stages: The first stage involves issuing an alarm signal when the hot section reheat steam velocity rises to a certain value, while simultaneously increasing the reheat steam pressure by closing the intermediate-pressure combined steam valve to alleviate the problem of rising reheat steam velocity. The second stage involves mitigating the problem by limiting the opening of the newly added low-pressure bypass valve, i.e., limiting the increase in heat load, if the reheat steam velocity still does not drop to a reasonable range when the intermediate-pressure combined steam valve is closed to the minimum allowable opening. The third stage involves automatically closing the newly added low-pressure bypass valve to a certain degree while automatically opening the high-pressure bypass valve to a certain degree, thereby reducing the hot section reheat steam flow rate and increasing its pressure to quickly reduce the hot section reheat steam velocity.

[0104] An automatic control method for reheat steam flow rate applicable to high and low pressure bypass heating, the specific scheme of which includes:

[0105] (1) The reheat steam velocity monitoring device suitable for high and low pressure bypass heating has realized real-time monitoring of the reheat steam velocity in the hot section. When the device detects the reheat steam velocity v in the hot section... rh When the first control threshold a (in meters per second) is reached, a "High Reheat Steam Flow Rate" alarm pop-up appears on the DCS "Heating Network System" screen. The control processor 1 then sends a "Close" command to the intermediate-pressure combined steam valve 6. The intermediate-pressure combined steam valve begins to gradually close at a rate of 2% / min until the reheat steam flow rate v... rh <a-1, or when the intermediate pressure combined steam valve reaches its minimum opening degree k (in %), stop closing the intermediate pressure combined steam valve.

[0106] (2) When the reheat steam velocity monitoring device detects the reheat steam velocity v in the hot section rhWhen the second control threshold b (in meters per second) is reached, the control processor 1 sends a "prohibit closing" command to the high-pressure bypass valve 7 and a "prohibit opening" command to the newly added low-pressure bypass valve 8. This prevents the newly added low-pressure bypass valve from opening further and the high-pressure bypass valve from closing further, thereby increasing the hot section reheat steam pressure, reducing the reheat steam specific volume, and thus reducing the reheat steam flow rate. When the hot section reheat steam flow rate v... rh After <b, the "Do Not Close" setting for the high-pressure bypass valve and the "Do Not Open" setting for the newly added low-pressure bypass valve are released, meaning that the high-pressure bypass valve and the newly added low-pressure bypass valve can be opened or closed arbitrarily.

[0107] (3) When the reheat steam velocity monitoring device detects the reheat steam velocity v in the hot section rh When the third control threshold c (unit: m / s) is reached, the control processor 1 sends a "2% over-relaxation" command to the high-pressure bypass valve 7 and a "2% over-relaxation" command to the newly added low-pressure bypass valve 8. This means that the high-pressure bypass valve is automatically opened by 2% and the newly added low-pressure bypass valve is automatically closed by 2% based on the current opening degree. Closing the newly added low-pressure bypass valve can reduce the amount of reheat steam supplied to the heating network, thereby reducing the total flow rate of reheat steam in the hot section. Opening the high-pressure bypass valve can increase the amount of steam supplied to the reheat steam pipeline by the high-pressure bypass valve, thereby increasing the reheat steam pressure and reducing the specific volume of reheat steam, thus rapidly reducing the reheat steam flow rate in a short period of time. To avoid the continuous automatic opening and closing of the high-pressure bypass valve and the newly added low-pressure bypass valve causing oscillations in the system operation, the automatic opening / closing 2% command is set to be triggered only once within 10 minutes, and the over-relaxation amount of 2% is restored at a rate of 0.4% / min after 10 minutes.

[0108] (4) When the unit's thermal load decreases or the electrical load increases, the reheat steam velocity in the hot section will decrease. When the reheat steam velocity monitoring device detects the reheat steam velocity v in the hot section... rh When the value is less than the first reset threshold d (in meters per second), the control processor 1 sends an "open" command to the intermediate pressure combined steam valve 6, and the intermediate pressure combined steam valve begins to open gradually at a rate of 2% / min until it is fully open.

[0109] It should be noted that in the above control scheme, the values ​​of the first, second, and third control thresholds, the first reset threshold, and the minimum opening degree k of the intermediate-pressure combined steam valve can be selected according to the actual situation of the unit. Generally, the following conditions must be met: first reset threshold d < first control threshold a < second control threshold b < third control threshold c. In some embodiments of the present invention, the first reset threshold d can be 60 m / s, the first control threshold a can be 70 m / s, the second control threshold b can be 74 m / s, the third control threshold c can be 78 m / s, and the minimum opening degree k of the intermediate-pressure combined steam valve can be 30%.

[0110] Based on the same inventive concept, this application also provides a high- and low-pressure bypass heating reheat steam flow rate monitoring device, which can be used to implement the method described in the above embodiments, as described in the following embodiments. Since the principle of this high- and low-pressure bypass heating reheat steam flow rate monitoring device is similar to that of the high- and low-pressure bypass heating reheat steam flow rate monitoring method, the implementation of the high- and low-pressure bypass heating reheat steam flow rate monitoring device can refer to the implementation of the high- and low-pressure bypass heating reheat steam flow rate monitoring method, and repeated details will not be elaborated further. As used below, the terms "unit" or "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the system described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0111] According to another aspect of this application, a high- and low-pressure bypass heating reheat steam flow rate monitoring device is also provided, such as... Figure 5 As shown, it includes:

[0112] Thermal data acquisition unit 501: Real-time relevant thermal data of the high-pressure bypass heating system under current operating conditions;

[0113] The parameter calculation unit 502 determines the parameters required for calculating the reheat steam velocity in the hot section based on relevant thermodynamic data.

[0114] Steam mass flow unit 503 obtains the steam mass flow rate of hot section reheat steam entering the intermediate pressure cylinder and steam passing through the newly added low bypass valve based on the Flügler formula, the valve flow characteristic function of the newly added low bypass valve and relevant thermodynamic data.

[0115] The reheat steam velocity unit 504 is used to determine the reheat steam velocity in the hot section based on the hot section reheat steam mass flow rate and related thermodynamic data.

[0116] In one embodiment, such as Figure 6 As shown, the parameter calculation unit 502 includes:

[0117] Application module 601 is used for macros that calculate the properties of water and water vapor;

[0118] The specific volume calculation module 602 is used to determine the specific volume of the hot section reheat steam based on the pressure and temperature of the hot section reheat steam in the relevant thermodynamic data.

[0119] In one embodiment, the steam mass flow unit includes:

[0120] The steam mass flow calculation module is used to calculate the steam mass flow rate of hot section reheat steam entering the intermediate pressure cylinder by applying the Flügger formula and the steam pressure after the intermediate pressure combined steam valve and the extraction steam pressure of the four sections of the intermediate pressure cylinder in the relevant thermodynamic data; and to calculate the steam mass flow rate of hot section reheat steam passing through the newly added low-pressure bypass valve by applying the flow characteristic function of the newly added low-pressure bypass valve and the steam differential pressure before and after the newly added low-pressure bypass valve and the valve opening of the newly added low-pressure bypass valve in the relevant thermodynamic data.

[0121] In one embodiment, the reheat steam flow rate unit includes:

[0122] The reheat steam velocity calculation module is used to determine the reheat steam velocity in the hot section based on the reheat steam mass flow rate and related thermodynamic data.

[0123] This application enables real-time dynamic monitoring of the reheat steam velocity in the hot section of high and low pressure bypass heating units. When the velocity is too high, an automatic control scheme can issue an alarm and take corresponding measures to promptly control the reheat steam velocity to a reasonable range, preventing excessively fast steam velocity from eroding and damaging pipelines and equipment, thus affecting the safe operation of the unit. At the same time, the application of this application realizes automatic monitoring and automatic control of reheat steam velocity, which can significantly reduce the workload of operators and reduce errors that may be caused by manual operation, improve the automation level of unit operation, and ensure the safety and stability of high and low pressure bypass heating units during long-term operation.

[0124] This application also provides a specific implementation of an electronic device capable of implementing all the steps in the methods described above. See [link to implementation details]. Figure 7 The electronic device specifically includes the following:

[0125] Processor 701, memory 702, communications interface 703, bus 704, and non-volatile memory 705;

[0126] The processor 701, memory 702, and communication interface 703 communicate with each other through the bus 704.

[0127] The processor 701 is used to call the computer program in the memory 702 and the non-volatile memory 705. When the processor executes the computer program, it implements all the steps in the method in the above embodiments. For example, when the processor executes the computer program, it implements the following steps:

[0128] S301: Collects real-time relevant thermal data of the high and low pressure bypass heating system under current operating conditions.

[0129] S302: Determine the parameters required for calculating the reheat steam velocity in the hot section based on relevant thermodynamic data.

[0130] S303: The steam mass flow rate of reheat steam entering the intermediate pressure cylinder in the hot section is obtained based on the Freuger formula and relevant thermodynamic data.

[0131] S304: Calculate the steam mass flow rate of hot section reheat steam through the new low bypass valve based on the flow characteristic function of the new low bypass valve.

[0132] S305: Determine the reheat steam velocity in the hot section based on the hot section reheat steam mass flow rate and relevant thermodynamic data.

[0133] Embodiments of this application also provide a computer-readable storage medium capable of implementing all steps of the methods in the above embodiments. The computer-readable storage medium stores a computer program that, when executed by a processor, implements all steps of the methods in the above embodiments. For example, when the processor executes the computer program, it implements the following steps:

[0134] S301: Collects real-time relevant thermal data of the high and low pressure bypass heating system under current operating conditions.

[0135] S302: Determine the parameters required for calculating the reheat steam velocity in the hot section based on relevant thermodynamic data.

[0136] S303: The steam mass flow rate of reheat steam entering the intermediate pressure cylinder in the hot section is obtained based on the Freuger formula and relevant thermodynamic data.

[0137] S304: Calculate the steam mass flow rate of hot section reheat steam through the new low bypass valve based on the flow characteristic function of the new low bypass valve.

[0138] S305: Determine the reheat steam velocity in the hot section based on the hot section reheat steam mass flow rate and relevant thermodynamic data.

[0139] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on its differences from other embodiments. In particular, for hardware + program embodiments, since they are basically similar to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. Although the embodiments in this specification provide the method operation steps as shown in the embodiments or flowcharts, more or fewer operation steps may be included based on conventional or non-inventive means. The order of steps listed in the embodiments is merely one possible execution order among many steps and does not represent the only execution order. In actual device or terminal product execution, the methods can be executed in the order shown in the embodiments or drawings or in parallel (e.g., in a parallel processor or multi-threaded processing environment, or even a distributed data processing environment). The terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, product, or apparatus that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, product, or apparatus. Without further limitations, the presence of other identical or equivalent elements in the process, method, product, or apparatus that includes said elements is not excluded. For ease of description, the above devices are described in terms of function, divided into various modules. Of course, in implementing the embodiments of this specification, the functions of each module can be implemented in one or more software and / or hardware, or the module implementing the same function can be implemented by a combination of multiple sub-modules or sub-units, etc. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division; 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 devices or units may be electrical, mechanical, or other forms. This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the instructions, which are executable by the processor of the computer or other programmable data processing device, produce instructions for implementing the process. Figure 1 One or more processes and / or boxes Figure 1The apparatus is designed to perform the functions specified in one or more boxes. Those skilled in the art will understand that embodiments of this specification can be provided as methods, systems, or computer program products. Therefore, embodiments of this specification can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of this specification can take the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The various embodiments in this specification are described in a progressive manner, with reference to each other for similar or identical parts. Each embodiment focuses on describing the differences from other embodiments. In particular, system embodiments are generally similar to method embodiments, so the description is relatively simple, and relevant parts can be referred to in the description of the method embodiments. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of the embodiments of this specification. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples, without contradiction. The above descriptions are merely examples of embodiments of this specification and are not intended to limit the embodiments of this specification. Various modifications and variations can be made to the embodiments of this specification by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the embodiments of this specification should be included within the scope of the claims of the embodiments of this specification.

Claims

1. A method for controlling the reheat steam flow rate in high and low pressure bypass heating systems, characterized in that, include: Collect relevant thermal data of the high and low pressure bypass heating system under the current operating conditions; The parameters required for calculating the reheat steam velocity in the hot section are determined based on the relevant thermodynamic data. The steam mass flow rate of the hot section reheat steam entering the intermediate pressure cylinder is obtained based on the Flügler formula and the relevant thermodynamic data. The steam mass flow rate of reheat steam passing through the newly added low-voltage bypass valve is calculated based on the flow characteristic function of the new low-voltage bypass valve, specifically including: The steam mass flow rate of the hot section reheat steam through the new low-pressure bypass valve is calculated by applying the flow characteristic function of the new low-pressure bypass valve and the steam differential pressure before and after the new low-pressure bypass valve and the valve opening of the new low-pressure bypass valve in the relevant thermodynamic data. The reheat steam velocity in the hot section is determined based on the hot section reheat steam mass flow rate and the relevant thermodynamic data. When the reheat steam flow rate in the hot section is detected to be greater than the first control threshold, an alarm pop-up window for high reheat steam flow rate will appear, and a closing command will be sent to the intermediate pressure combined steam valve. The intermediate pressure combined steam valve will start to gradually close at a rate of 2% / min until the reheat steam flow rate is less than the first control threshold minus 1, or the intermediate pressure combined steam valve reaches its minimum opening, and the closure of the intermediate pressure combined steam valve will stop. When the hot section reheat steam flow rate is detected to be greater than the second control threshold, a command to prohibit closing is sent to the high-pressure bypass valve and a command to prohibit opening is sent to the newly added low-pressure bypass valve. At this time, the newly added low-pressure bypass valve is prohibited from opening further and the high-pressure bypass valve is prohibited from closing further, thereby increasing the hot section reheat steam pressure and reducing the reheat steam specific volume. When the hot section reheat steam flow rate is less than the second control threshold, the command to prohibit closing the high-pressure bypass valve and the command to prohibit opening the newly added low-pressure bypass valve are released. When the reheat steam flow rate in the hot section is detected to be greater than the third control threshold, a 2% over-relaxation command is sent to the high-pressure bypass valve and a 2% over-relaxation command is sent to the newly added low-pressure bypass valve. Based on the current opening degree, the high-pressure bypass valve is automatically opened by 2% and the newly added low-pressure bypass valve is automatically closed by 2%. The automatic opening / closing command of 2% is set to be triggered only once within 10 minutes, and the 2% over-relaxation amount is restored at a rate of 0.4% / min after 10 minutes. When the unit's thermal load decreases or electrical load increases, the hot section reheat steam flow rate decreases. When the hot section reheat steam flow rate is detected to be less than the first reset threshold, an opening command is sent to the intermediate pressure combined steam valve. The intermediate pressure combined steam valve begins to open gradually at a rate of 2% / min until it is fully open. Wherein, the first reset threshold is less than the first control threshold, the first control threshold is less than the second control threshold, and the second control threshold is less than the third control threshold.

2. The method for controlling the reheat steam flow rate in high and low pressure bypass heating according to claim 1, characterized in that, The step of determining the parameters required for calculating the reheat steam velocity in the hot section based on the relevant thermodynamic data includes: Calculate macros using the properties of water and water vapor; The specific volume of the hot section reheat steam is determined based on the pressure and temperature of the hot section reheat steam in the relevant thermodynamic data.

3. The method for controlling the reheat steam flow rate in high and low pressure bypass heating according to claim 1, characterized in that, The process of obtaining the steam mass flow rate of the hot section reheat steam entering the intermediate pressure cylinder based on the Freuger formula and the relevant thermodynamic data includes: The mass flow rate of reheat steam entering the intermediate pressure cylinder is calculated by applying the Flügler formula using the steam pressure after the intermediate pressure combined steam valve and the extraction steam pressure of the fourth stage of the intermediate pressure cylinder from relevant thermodynamic data.

4. The method for controlling the reheat steam flow rate in high and low pressure bypass heating according to claim 1, characterized in that, The step of determining the reheat steam velocity in the hot section based on the hot section reheat steam mass flow rate and the relevant thermodynamic data includes: The hot section reheat steam mass flow rate is determined by summing the steam mass flow rate of the hot section reheat steam entering the intermediate pressure cylinder and the steam mass flow rate of the hot section reheat steam passing through the newly added low bypass valve. The hot section reheat steam velocity is then determined by combining the specific volume of the hot section reheat steam and the inner diameter of the hot section reheat steam pipeline.

5. A high- and low-pressure bypass heating reheat steam flow rate control device, used to implement the high- and low-pressure bypass heating reheat steam flow rate control method as described in claim 1, characterized in that, include: The thermal data acquisition unit is used to collect relevant thermal data of the high and low pressure bypass heating system in real time under the current operating conditions; The parameter calculation unit is used to determine the parameters required for calculating the reheat steam flow rate in the hot section based on the relevant thermodynamic data. The steam mass flow unit is used to obtain the steam mass flow rate of hot section reheat steam entering the intermediate pressure cylinder and passing through the newly added low bypass valve, based on the Flügler formula, the valve flow characteristic function of the newly added low bypass valve, and the relevant thermodynamic data. The reheat steam velocity unit is used to determine the reheat steam velocity in the hot section based on the hot section reheat steam mass flow rate and the relevant thermodynamic data. The steam mass flow unit includes: a steam mass flow calculation module; The steam mass flow rate calculation module is used to calculate the steam mass flow rate of the hot section reheat steam through the new low-pressure bypass valve by applying the flow characteristic function of the new low-pressure bypass valve and the steam differential pressure before and after the new low-pressure bypass valve and the valve opening of the new low-pressure bypass valve in the relevant thermodynamic data. The device further includes: a flow rate control unit; The flow rate control unit is used to pop up an alarm window for high reheat steam flow rate when the reheat steam flow rate in the hot section is detected to be greater than the first control threshold, and send a closing command to the intermediate pressure combined steam valve. The intermediate pressure combined steam valve starts to gradually close at a rate of 2% / min until the reheat steam flow rate is less than the first control threshold minus 1, or the intermediate pressure combined steam valve reaches its minimum opening, and then stops closing the intermediate pressure combined steam valve. The flow rate control unit is used to send a command to the high-pressure bypass valve to prevent it from closing and a command to the newly added low-pressure bypass valve to prevent it from opening when the hot section reheat steam flow rate is detected to be greater than the second control threshold. At this time, the newly added low-pressure bypass valve is prohibited from opening further and the high-pressure bypass valve is prohibited from closing further, thereby increasing the hot section reheat steam pressure and reducing the reheat steam specific volume. When the hot section reheat steam flow rate is less than the second control threshold, the command to prevent the high-pressure bypass valve from closing and the command to prevent the newly added low-pressure bypass valve from opening are released. The flow rate control unit is used to send a 2% over-relaxation command to the high-pressure bypass valve and a 2% over-relaxation command to the newly added low-pressure bypass valve when the reheat steam flow rate in the hot section is detected to be greater than the third control threshold. It automatically opens the high-pressure bypass valve by 2% and automatically closes the newly added low-pressure bypass valve by 2% based on the current opening degree. The automatic opening / closing command of 2% is set to be triggered only once within 10 minutes, and the over-relaxation amount of 2% is restored at a rate of 0.4% / min after 10 minutes. The flow rate control unit is used to reduce the flow rate of hot section reheat steam when the unit's thermal load decreases or electrical load increases. When the hot section reheat steam flow rate is detected to be less than the first reset threshold, an opening command is sent to the intermediate pressure combined steam valve. The intermediate pressure combined steam valve begins to open gradually at a rate of 2% / min until it is fully open. Wherein, the first reset threshold is less than the first control threshold, the first control threshold is less than the second control threshold, and the second control threshold is less than the third control threshold.

6. The high and low pressure bypass heating reheat steam flow rate control device according to claim 5, characterized in that, The parameter calculation unit includes: Application module, used for macros that calculate the properties of water and water vapor; The specific volume calculation module is used to determine the specific volume of the hot section reheat steam based on the pressure and temperature of the hot section reheat steam in the relevant thermodynamic data.

7. The high and low pressure bypass heating reheat steam flow rate control device according to claim 5, characterized in that, The steam mass flow unit includes: The steam mass flow calculation module is used to calculate the steam mass flow rate of the hot section reheat steam entering the intermediate pressure cylinder by applying the Flügger formula and using the steam pressure after the intermediate pressure combined steam valve and the extraction steam pressure of the fourth section of the intermediate pressure cylinder from relevant thermodynamic data.

8. The high and low pressure bypass heating reheat steam flow rate control device according to claim 7, characterized in that, The reheat steam flow rate unit includes: The reheat steam velocity calculation module is used to determine the hot section reheat steam mass flow rate based on the sum of the steam mass flow rate of the reheat steam entering the intermediate pressure cylinder and the steam mass flow rate of the hot section reheat steam passing through the newly added low bypass valve, and then determine the hot section reheat steam velocity by combining the specific volume of the hot section reheat steam and the inner diameter of the hot section reheat steam pipeline.

9. A high- and low-pressure bypass heating reheat steam flow rate monitoring device, characterized in that, include: A CPU processor, a boiler, a high-pressure cylinder, a medium-pressure cylinder, a first heating network heater, and a second heating network heater; The boiler is connected to the high-pressure cylinder through a first main pipe; the first main pipe branches off into a first side pipe branch, which connects the first main pipe to the exhaust pipe of the high-pressure cylinder. The boiler is connected to the intermediate pressure cylinder via a second main pipe; a second bypass pipe branch is branched off from the second main pipe, and the second bypass pipe branch is connected to the exhaust pipe of the intermediate pressure cylinder; The exhaust pipe of the intermediate pressure cylinder is connected to the first heating network heater and the second heating network heater respectively; The CPU processor's input interface is connected in communication with the pipeline in the high and low pressure bypass heating system to collect steam data from the pipeline. A method for monitoring the reheat steam flow rate in high- and low-pressure bypass heating is incorporated into the CPU processor. The CPU processor is used to collect real-time relevant thermodynamic data of the high- and low-pressure bypass heating system under current operating conditions; determine the parameters required for calculating the hot-section reheat steam flow rate based on the relevant thermodynamic data; obtain the steam mass flow rate of the hot-section reheat steam entering the intermediate-pressure cylinder based on the Früger formula and the relevant thermodynamic data; and calculate the steam mass flow rate of the hot-section reheat steam passing through the newly added low-pressure bypass valve based on the flow characteristic function of the newly added low-pressure bypass valve. Specifically, this includes: applying the flow characteristic function of the newly added low-pressure bypass valve to calculate the steam mass flow rate of the hot-section reheat steam passing through the newly added low-pressure bypass valve using the steam differential pressure before and after the newly added low-pressure bypass valve and the valve opening of the newly added low-pressure bypass valve from the relevant thermodynamic data; and determining the hot-section reheat steam flow rate based on the hot-section reheat steam mass flow rate and the relevant thermodynamic data. The CPU processor is also used to, when detecting that the hot section reheat steam flow rate is greater than the first control threshold, pop up an alarm window indicating a high reheat steam flow rate and send a closing command to the intermediate-pressure combined steam valve. The intermediate-pressure combined steam valve begins to gradually close at a rate of 2% / min until the reheat steam flow rate is less than the first control threshold minus 1, or the intermediate-pressure combined steam valve reaches its minimum opening, at which point the closure of the intermediate-pressure combined steam valve stops. When detecting that the hot section reheat steam flow rate is greater than the second control threshold, a command to prohibit closing is sent to the high-pressure bypass valve and a command to prohibit opening is sent to the newly added low-pressure bypass valve. At this time, the newly added low-pressure bypass valve is prohibited from further opening, and the high-pressure bypass valve is prohibited from further closing, thereby increasing the hot section reheat steam pressure and reducing the reheat steam specific volume. When the hot section reheat steam flow rate is less than the second control threshold, the command to prohibit closing the high-pressure bypass valve and the command to prohibit opening the newly added low-pressure bypass valve are released. When detecting... When the hot section reheat steam velocity exceeds the third control threshold, a 2% over-relaxation command is sent to the high-pressure bypass valve, and a 2% over-relaxation command is sent to the newly added low-pressure bypass valve. Based on the current opening degree, the high-pressure bypass valve is automatically opened by 2%, and the newly added low-pressure bypass valve is automatically closed by 2%. This automatic 2% opening / closing command is set to be triggered only once within 10 minutes, and the 2% over-relaxation is restored at a rate of 0.4% / min after 10 minutes. When the unit's thermal load decreases or electrical load increases, the hot section reheat steam velocity decreases. When the hot section reheat steam velocity is detected to be less than the first reset threshold, an opening command is sent to the intermediate-pressure combined steam valve. The intermediate-pressure combined steam valve begins to gradually open at a rate of 2% / min until it is fully open. The first reset threshold is less than the first control threshold, the first control threshold is less than the second control threshold, and the second control threshold is less than the third control threshold.

10. The high and low pressure bypass heating reheat steam flow rate monitoring device according to claim 9, characterized in that, A high-pressure main steam valve is provided at the connection between the first main pipeline and the high-pressure cylinder, and a high-pressure bypass valve is provided on the branch of the first bypass pipeline.

11. The high and low pressure bypass heating reheat steam flow rate monitoring device according to claim 9, characterized in that, A medium-pressure combined steam valve is installed at the connection between the second main pipeline and the medium-pressure cylinder, and a new low-pressure bypass valve is installed at the connection between the second bypass branch and the exhaust pipeline of the medium-pressure cylinder.

12. The high and low pressure bypass heating reheat steam flow rate monitoring device according to claim 9, characterized in that, A control valve is installed at the inlet of the first heating network heater and the second heating network heater, respectively.

13. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the high and low pressure bypass heating reheat steam flow rate control method according to any one of claims 1 to 4.

14. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the high and low pressure bypass heating reheat steam flow rate control method according to any one of claims 1 to 4.

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