Device for dry and wet state automatic switching of 600MW supercritical boiler

Abstract

The application discloses a device for 600MW supercritical boiler dry and wet state automatic switching, and relates to the technical field of control devices; the device comprises a dry and wet state switching module; the dry and wet state switching module is used for obtaining the air pressure value in a steam-water separator of a water storage tank, obtaining the liquid state in the water storage tank, obtaining the instruction information of dry state to liquid state when the air pressure value is in the range of 10MPa-11MPa and there is liquid in the water storage tank, and obtaining the instruction information of liquid state to dry state when the air pressure value exceeds 11MPa and there is no liquid in the water storage tank; and the device realizes the automatic switching of the dry state and the wet state of the boiler through the dry and wet state switching module and the like.

Description

Technical Field

[0001] This invention relates to the field of control device technology, and in particular to a device for automatic switching between dry and wet states in a 600MW supercritical boiler. Background Technology

[0002] The author conducted a search using the formula (TACD = (boiler AND dry state AND wet state AND (conversion OR switching))) and obtained the following closest existing technical solutions.

[0003] The application, published under CN115826651A, is titled "A Deep Peak-Shaving Dry-Wet Conversion Control System Based on an Expanded State Observer." The method includes the following steps: Step 1, collecting data on inlet water flow, tank water level, actual enthalpy, inlet pressure, and coal feed rate during the dry-wet conversion process of a thermal power unit; Step 2, constructing a water tank level control system based on an expanded state observer, estimating the inlet water flow and tank water level using the expanded state observer, and then controlling the flow opening degree through PID control; Step 3, achieving automatic control of wet-to-dry and dry-to-wet transitions through the dry-wet conversion control system; Step 4, introducing weighting factors to online correct the expanded state observer model parameters during load variation. This control strategy effectively improves the control quality of the coordinated control system for large thermal power units under deep peak-shaving conditions. The control system exhibits fast response speed, good stability, high accuracy, good robustness, and a certain degree of adaptability.

[0004] The authorization announcement number is CN113864849B, entitled "Dry-Wet State Seamless Switching System and Control Method Applicable to Deep Peak Shaving of Supercritical Units." It includes: a water storage tank with a tee valve connected to the outlet and the inlet connected to the separator outlet; a hot water circulation system connected to the water storage tank outlet, configured to use a hot water circulation pump to circulate saturated water from the tank to the economizer inlet, then through the water-cooled wall to the separator, achieving working fluid recirculation; and a water storage tank level micro-adjustment system, including a deaerator and a high-pressure heater connected to the water storage tank outlet, used to guide saturated water from the tank to the deaerator, where it is heated by the high-pressure heater and then circulated to the economizer and water-cooled wall before reaching the separator. This switching system enables flexible dry-wet state switching of the unit and long-term flexible peak shaving of supercritical units from 20% to 100% load, ensuring safe and stable operation of the unit. Furthermore, it reduces start-up time, working fluid and heat discharge during the unit startup phase, achieving effective heat recovery.

[0005] Based on the two patent documents mentioned above and existing technical solutions, the inventors analyze the existing technical solutions as follows.

[0006] Supercritical once-through boilers operate in both dry and wet modes during low-load conditions. When process parameters reach certain values, a switch between dry and wet modes is required. Wet operation typically occurs only during unit startup and shutdown, without prolonged periods in wet mode. However, as peak load regulation deepens and the load decreases, the frequency of wet operation increases, necessitating frequent dry-wet mode switching. Currently, automatic control of the dry-wet mode switching process is limited, often requiring manual control by experienced professionals. Improper control can lead to significant fluctuations in main steam temperature, potentially causing widespread boiler overheating or superheater water ingress, severely impacting the safe operation of the unit.

[0007] Existing technical issues and considerations:

[0008] How to solve the technical problem of automatic switching between dry and wet states in boilers. Summary of the Invention

[0009] This invention provides a device for automatic switching between dry and wet states in a 600MW supercritical boiler, solving the technical problem of automatic switching between dry and wet states in boilers.

[0010] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0011] A device for automatic switching between dry and wet states in a 600MW supercritical boiler includes a dry-wet state switching module. The dry-wet state switching module is used to obtain the gas pressure value in the steam-water separator of the water storage tank and the liquid state in the water storage tank. When the gas pressure value is within the range of 10MPa to 11MPa and there is liquid in the water storage tank, it obtains the instruction information for switching from dry state to liquid state; when the gas pressure value exceeds 11MPa and there is no liquid in the water storage tank, it obtains the instruction information for switching from liquid state to dry state.

[0012] A further technical solution is that the dry / wet switching module is also used to send command information to the 361 valve. When the command information is from dry to liquid, the 361 valve is turned on; when the command information is from liquid to dry, the 361 valve is turned off.

[0013] A further technical solution is that the dry-wet switching module is also used to send instruction information to the boiler drain pump and drain valve. The boiler drain pump and drain valve receive the instruction information. When the instruction information is from dry to liquid, the boiler drain pump works and the drain valve is turned on. When the instruction information is from liquid to dry, the boiler drain pump stops and the drain valve is closed.

[0014] A device for automatic dry / wet switching in a 600MW supercritical boiler includes a controller, a water storage tank, a steam-water separator, a 361 valve, and a dry / wet switching module. The steam-water separator is connected to the water storage tank, and the water storage tank is connected to the 361 valve. A barometer is installed on the steam-water separator to obtain the air pressure value in the separator. A level gauge is installed at the bottom of the water storage tank to obtain the liquid state in the tank. The barometer and the level gauge are connected to and communicate with the controller. The device connects and communicates with the 361 valve. The dry / wet state switching module is used by the controller to obtain the air pressure value in the water tank's air-water separator sent by the barometer, and the controller to obtain the liquid state in the water tank sent by the level gauge. When the air pressure value is within the range of 10MPa to 11MPa and there is liquid in the water tank, the controller generates a command to switch from dry to liquid state; when the air pressure value exceeds 11MPa and there is no liquid in the water tank, the controller generates a command to switch from liquid to dry state. The controller sends the command information to the 361 valve.

[0015] A further technical solution includes a boiler condensate tank, a boiler condensate pump, a condensate regulating valve, and an exhaust device. The 361 valve, boiler condensate tank, boiler condensate pump, condensate regulating valve, and exhaust device are sequentially connected and conductive. The controller is connected and communicates with the boiler condensate pump and the condensate regulating valve. The dry / wet state switching module is also used for the controller to send command information to the boiler condensate pump and the condensate regulating valve. The 361 valve, boiler condensate pump, and condensate regulating valve receive the command information. When the command information is from dry to liquid state, the 361 valve is conductive, the boiler condensate pump works, and the condensate regulating valve is conductive. When the command information is from liquid to dry state, the 361 valve is closed, the boiler condensate pump stops, and the condensate regulating valve is closed.

[0016] A further technical solution includes a high-pressure heater, a water inlet valve, a water inlet gate, an economizer, and a water-cooled wall. The steam-water separator includes a first steam-water separator and a second steam-water separator. The high-pressure heater is connected to the economizer via the water inlet valve and the economizer via the water inlet gate. The economizer is connected to the water-cooled wall. The water-cooled wall is connected to the water storage tank via the first steam-water separator. The second steam-water separator is connected to the water storage tank. A pressure gauge is installed on the second steam-water separator.

[0017] A further technical solution includes a management terminal, with the controller connected and communicating with the management terminal, and a dry / wet switching module, which is used by the controller to send instruction information to the management terminal and facilitates monitoring by management personnel when needed.

[0018] A further technical solution involves using a fixed terminal as the management terminal, which is wired to the controller.

[0019] A further technical solution involves using a mobile terminal as the management terminal, which is wirelessly connected to the controller.

[0020] A further technical solution is a dry / wet switching module, which is used to manage the terminal to receive, record, and display the instruction information sent by the controller so that managers can view it.

[0021] The beneficial effects of adopting the above technical solution are as follows:

[0022] First, a device for automatic dry / wet switching in a 600MW supercritical boiler includes a dry / wet switching module. This module obtains the gas pressure value in the steam-water separator of the water storage tank and the liquid state in the tank. When the gas pressure is within the range of 10MPa to 11MPa and there is liquid in the water storage tank, it obtains a command to switch from dry to liquid state; when the gas pressure exceeds 11MPa and there is no liquid in the water storage tank, it obtains a command to switch from liquid to dry state. This technical solution achieves automatic dry / wet switching of the boiler through the dry / wet switching module, etc.

[0023] Second, a device for automatic dry / wet switching in a 600MW supercritical boiler includes a controller, a water storage tank, a steam-water separator, a 361 valve, and a dry / wet switching module. The steam-water separator is connected to the water storage tank, and the water storage tank is connected to the 361 valve. A barometer is installed on the steam-water separator to obtain the air pressure value in the separator. A level gauge is installed at the bottom of the water storage tank to obtain the liquid state in the tank. Both the barometer and the level gauge are connected to and communicate with the controller. The controller connects and communicates with the 361 valve. The dry / wet switching module is used by the controller to obtain the air pressure value from the gas-water separator in the water storage tank sent by the barometer, and the liquid status in the water storage tank sent by the level gauge. When the air pressure value is within the range of 10MPa to 11MPa and there is liquid in the water storage tank, the controller generates a command to switch from dry to liquid state; when the air pressure value exceeds 11MPa and there is no liquid in the water storage tank, the controller generates a command to switch from liquid to dry state. The controller then sends the command information to the 361 valve. This technical solution, through the dry / wet switching module, achieves automatic switching between dry and wet states in the boiler.

[0024] See the detailed implementation section for further description. Attached Figure Description

[0025] Figure 1 This is a distribution diagram of Embodiment 2 of the present invention;

[0026] Figure 2 This is a principle block diagram of Embodiment 2 of the present invention;

[0027] Figure 3 This is a principle block diagram of Embodiment 3 of the present invention;

[0028] Figure 4 This is the logic diagram of the present invention. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0030] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0031] Example 1:

[0032] This invention discloses a device for automatic switching between dry and wet states in a 600MW supercritical boiler, comprising a dry-wet state switching module. This module obtains the gas pressure value in the steam-water separator of the water storage tank and the liquid state in the water storage tank. When the gas pressure value is equal to or less than 11MPa and there is liquid in the water storage tank, it obtains a command message for switching from dry to liquid state; when the gas pressure value exceeds 11MPa and there is no liquid in the water storage tank, it obtains a command message for switching from liquid to dry state. The command message is sent to a 361 valve, a boiler drain pump, and a drain control valve. Upon receiving the command message, when the command message indicates a switch from dry to liquid state, the 361 valve is activated, the boiler drain pump operates, and the drain control valve is activated; when the command message indicates a switch from liquid to dry state, the 361 valve is closed, the boiler drain pump is paused, and the drain control valve is closed.

[0033] Example 2:

[0034] like Figure 1 and Figure 2As shown, this invention discloses a device for automatic dry / wet switching of a 600MW supercritical boiler, comprising a controller, a high-pressure heater, a water inlet regulating valve, a water inlet gate, an economizer, a water-cooled wall, a water storage tank, a steam-water separator, a 361 valve, a boiler drain tank, a boiler drain pump, a drain regulating valve, an exhaust device, and a dry / wet switching module. The high-pressure heater is also known as a high-pressure heater, and the steam-water separator includes a first steam-water separator and a second steam-water separator. The high-pressure heater is connected to the economizer via the water inlet regulating valve, and the high-pressure heater is connected to the water inlet gate... The valve is connected to the economizer, the economizer is connected to the water-cooled wall, the water-cooled wall is connected to the water storage tank via the first steam-water separator, the second steam-water separator is connected to the water storage tank, the water storage tank is connected to the 361 valve, the 361 valve, the boiler drain tank, the boiler drain pump, the drain regulating valve and the exhaust device are connected in sequence. A barometer is installed on the second steam-water separator to obtain the air pressure value in the steam-water separator. A level gauge is installed at the bottom of the water storage tank to obtain the liquid state in the water storage tank.

[0035] like Figure 2 As shown, the barometer is connected to and communicates with the controller, the level gauge is connected to and communicates with the controller, the controller is connected to and communicates with the 361 valve, the controller is connected to and communicates with the boiler drain pump, and the controller is connected to and communicates with the drain regulating valve.

[0036] The dry / wet switching module is used by the controller to obtain the air pressure value in the steam-water separator of the water storage tank from the barometer, and the liquid state in the water storage tank from the level gauge. When the air pressure value is within the range of 10MPa to 11MPa and there is liquid in the water storage tank, the controller generates a command to switch from dry to liquid state. When the air pressure value exceeds 11MPa and there is no liquid in the water storage tank, the controller generates a command to switch from liquid to dry state. The controller sends the command information to the 361 valve, boiler drain pump, and drain control valve. When the command information is for switching from dry to liquid state, the 361 valve is open, the boiler drain pump works, and the drain control valve is open. When the command information is for switching from liquid to dry state, the 361 valve is closed, the boiler drain pump is paused, and the drain control valve is closed.

[0037] The controller, high-pressure heater, water inlet valve, water inlet gate, economizer, water-cooled wall, water storage tank, steam-water separator, 361 valve, boiler drain tank, boiler drain pump, drain valve and exhaust device themselves, as well as the corresponding connection technology, are existing technologies and will not be described in detail here.

[0038] Example 3:

[0039] The difference between Example 3 and Example 2 is that Example 3 also includes a management terminal.

[0040] like Figure 1 and Figure 3As shown, this invention discloses a device for automatic dry / wet switching of a 600MW supercritical boiler, comprising a management terminal, a controller, a high-pressure heater, a water inlet valve, a water inlet gate, an economizer, a water-cooled wall, a water storage tank, a steam-water separator, a 361 valve, a boiler drain tank, a boiler drain pump, a drain valve, an exhaust device, and a dry / wet switching module. The high-pressure heater is also known as a high-pressure heater, and the steam-water separator includes a first steam-water separator and a second steam-water separator. The high-pressure heater is connected to the economizer via the water inlet valve, and the high-pressure heater is connected to the economizer via... The water inlet gate is connected to the economizer, the economizer is connected to the water-cooled wall, the water-cooled wall is connected to the water storage tank via the first steam-water separator, the second steam-water separator is connected to the water storage tank, the water storage tank is connected to the 361 valve, the 361 valve, the boiler drain tank, the boiler drain pump, the drain regulating valve and the exhaust device are connected in sequence. A barometer is installed on the second steam-water separator to obtain the air pressure value in the steam-water separator. A level gauge is installed at the bottom of the water storage tank to obtain the liquid state in the water storage tank.

[0041] like Figure 3 As shown, the barometer is connected to and communicates with the controller, the level gauge is connected to and communicates with the controller, the controller is connected to and communicates with the 361 valve, the controller is connected to and communicates with the boiler drain pump, and the controller is connected to and communicates with the drain control valve. The management terminal is a mobile terminal, such as a smartphone, which wirelessly connects to and communicates with the controller.

[0042] The dry / wet switching module is used by the controller to obtain the air pressure value in the water tank's steam-water separator from the barometer and the liquid state in the water tank from the level gauge. When the air pressure value is within the range of 10MPa to 11MPa and there is liquid in the water tank, the controller generates a command to switch from dry to liquid state. When the air pressure value exceeds 11MPa and there is no liquid in the water tank, the controller generates a command to switch from liquid to dry state. The controller sends the command information to the 361 valve, boiler drain pump, and drain control valve. When the command information is for switching from dry to liquid state, the 361 valve is open, the boiler drain pump operates, and the drain control valve is open. When the command information is for switching from liquid to dry state, the 361 valve is closed, the boiler drain pump stops, and the drain control valve is closed. The controller sends the command information to the management terminal for monitoring by management personnel when needed. The management terminal receives the command information from the controller, records it, and displays it for management personnel to view.

[0043] In addition to the above embodiments, other embodiments can also be adopted, in which the management terminal is a fixed terminal, such as a desktop computer, and the fixed terminal is wired to the controller.

[0044] Compared to the above embodiments, the program module can also be a hardware module made using existing logic operation technology to implement the corresponding logic operation steps, communication steps and control steps, thereby realizing the above-mentioned corresponding steps. The logic operation unit is existing technology and will not be described in detail here.

[0045] Research and development process:

[0046] 1. The most fundamental technical problem to be solved

[0047] Currently, the dry / wet switching of 600MW supercritical once-through boilers is often manually operated by personnel. When the boiler operating parameters reach the switching conditions, the unit equipment and valves are manually switched from one state to another, and the unit parameters are adjusted to remain stable and unaffected by the switching operation. This technology enables the control system to accurately determine when the boiler parameters reach the switching conditions, achieving automatic switching between dry and wet states and adjusting the equipment control parameters, equipment, and valves to the target state.

[0048] 2 core technology solutions

[0049] 1. Improvements:

[0050] Introduction to the Dry and Wet State Switching Process of Supercritical Once-Through Boilers

[0051] The 600MW supercritical once-through boiler has two modes, dry and wet, during the low-load stage. When the load fluctuates between 20% and 30% of the rated load, the boiler will switch between dry and wet modes.

[0052] Dry-to-wet transition process: Reduce fuel quantity to lower the steam-water separator pressure to approximately 10 MPa, switch the inlet water valve to the bypass valve, and maintain the feedwater flow rate at approximately 480 t / h by jointly controlling the feedwater pump speed and the inlet water bypass valve; maintain the differential pressure across the inlet water valve at a level above 2 MPa, and switch the main desuperheating water to the standby desuperheating water; the feedwater, after being heated by the economizer and water-cooled walls, enters the steam-water separator, which separates saturated steam and saturated water. The steam enters the superheater for further heating, while the saturated water enters the steam-water separator's storage tank, where a water level appears. The level adjustment of the steam-water separator's storage tank is automatically controlled by valve 361. Continue to slowly reduce fuel quantity, causing the boiler condensate tank level to rise. Open the condensate tank drain valve; once the water quality is qualified, start the boiler condensate pump, controlling the condensate tank level through the condensate valve, and then close the condensate tank drain valve.

[0053] Wet-to-dry transition process: Maintain the steam-water separator pressure at approximately 10 MPa, gradually increasing the fuel supply to raise the load. The water level in the storage tank gradually decreases until it disappears, and valve 361 gradually closes until it is completely shut off. The economizer bypass valve controls the feedwater flow rate at approximately 480 t / h, and the differential pressure across the valve gradually decreases. The desuperheating water is switched from standby to normal, the main water supply valve is opened, and the bypass valve is closed. The boiler drain pump is shut down, the drain valve is closed, and the process transitions to a dry state. The feedwater flow rate is controlled by the feedwater pump speed. In the dry state, the feedwater flow rate is approximately 3:1 relative to the load. The heated feedwater is gradually converted into steam in the steam-water separator and enters the superheater for heating.

[0054] like Figure 1 As shown, another significant difference between dry and wet operation is that the relationship between main steam temperature control and feedwater flow rate is exactly the opposite when operating in dry and wet conditions. When operating in dry conditions, the main steam temperature decreases as the feedwater flow rate increases, while when operating in wet conditions, the main steam temperature increases as the feedwater flow rate increases. Therefore, the dry-wet transition process is the switching between water level control and minimum flow control in the storage tank, and between main steam temperature control and feedwater control.

[0055] 2. Wet Dynamic Model of DC Boiler

[0056] Main steam pipeline energy storage equation:

[0057]

[0058] The pressure change in the water storage tank indicates the energy balance of the separator and water storage tank system:

[0059]

[0060] Fitting function between saturated water enthalpy and pressure:

[0061] f1(P b ) = 45.55P b +952

[0062] Fitting function for the relationship between saturated vapor enthalpy and pressure:

[0063] f2(P b ) = -16.55P b +2891

[0064] Energy balance relationship of working fluid enthalpy in steam-water separator:

[0065]

[0066] Changes in the water level in the storage tank indicate the mass balance of the water tank.

[0067]

[0068] Where: u tMain valve opening, %; P b P is the separator outlet pressure, in MPa; t Main steam pressure, MPa; H sh Main steam enthalpy, kJ / kg; C t is the heat storage coefficient of the main steam pipeline, kJ / MPa; C is the pressure difference to flow rate ratio coefficient; W x The circulating water flow rate is expressed in t / h; W g Boiler feedwater, t / h; H i H represents the enthalpy of the working fluid at the separator inlet, in kJ / kg; Q represents the effective heat absorption of the boiler, in kJ / kg; H represents the effective heat absorption of the boiler, in kJ / kg. g Enthalpy of boiler feedwater, kJ / kg; C b is the separator heat storage coefficient, kJ / MPa; h is the separator liquid level; C H K is the heat storage coefficient of the economizer and water-cooled wall, kJ / MPa; k1 and k2 are internal coefficients.

[0069] By selecting operating parameters at 20% and 30% of rated load, the corresponding operating parameters for dry and wet operation can be obtained. Based on the operating parameters, the corresponding enthalpy of the working fluid can be obtained. The internal coefficients and the initial values ​​of functions f1 and f2 can be calculated using static calculation methods. Based on the initial values, the fitting can be adjusted to obtain the function expression for the corresponding load. Thus, a wet dynamic model of the once-through boiler can be built based on the obtained results to obtain the changes in the enthalpy of the separator inlet, the separator pressure, the main steam pressure, and the water level in the storage tank when the coal feed rate and water feed rate change.

[0070] 3. Multi-model switching strategy

[0071] When boiler parameters reach the switching node, the local controllers of the outer loop need to be switched. The matching error between the model output and the actual output is used as the system performance index to adjust the controller weights. At each sampling time, the controller weights corresponding to the local model are adjusted according to the magnitude of the performance index.

[0072] like Figure 4As shown, in the dry state, y0 is the set value of the enthalpy at the midpoint of the steam-water separator, and y is the actual enthalpy at the midpoint of the steam-water separator; in the wet state, y0 is the set value of the water level in the water storage tank of the steam-water separator, and y is the actual water level in the water storage tank. When the enthalpy at the midpoint is greater than the set value, i.e., the enthalpy at the corresponding set pressure, and the water level in the storage tank is at the lower limit (set to 0m), the system automatically switches to midpoint enthalpy control, controlling the water flow rate through the speed of the feed water pump, and the corresponding equipment and valves switch to dry operation. When the enthalpy at the midpoint is less than the set value, i.e., the enthalpy at the corresponding set pressure, and the water level in the storage tank is greater than the set value (0m), the system automatically switches to wet operation, controlling the water flow rate through the speed of the feed water pump and the water supply bypass valve, ensuring a pressure difference of more than 2MPa before and after the valve, automatically switching the desuperheating water to standby, and switching other equipment and valves to wet operation.

[0073] The concept of this application:

[0074] Automatic switching technology for dry and wet states in supercritical once-through boilers. The implementation of automatic switching technology can effectively improve the automation level of the unit, reduce human intervention, and when the boiler load reaches the node load, the advanced switching technology is used to automatically switch the equipment state by analyzing the boiler status parameters. This effectively reduces the workload of operators, reduces human error, and greatly improves the safety factor of the operating unit. If the dry-wet state conversion process of the once-through boiler can be achieved automatically with a single button, it will be a breakthrough in the automatic control of supercritical once-through units.

[0075] Additional notes:

[0076] Switcher Introduction

[0077] During system operation, the prediction outputs of the local models at sampling times k and n are z. 1i Given (k) (i = 1, 2, ..., n), the actual output of the controlled object is y(k), and the matching error between them is:

[0078]

[0079] In the formula, σ is a constant, 0 < σ ≤ 1. The sum of matching errors over a time period t is:

[0080]

[0081] In the formula, t is the cumulative rolling length of the matching error, which is generally the maximum modeling length of the model. Therefore, the recursive formula for the matching error can be obtained as follows:

[0082]

[0083] To reduce the importance of historical information, a forgetting factor λ for matching error is introduced, where 0 < λ < 1, resulting in:

[0084]

[0085] The cumulative initial value in the formula is e i (0,t)=0.

[0086] The output of the outer loop main controller is a weighted sum of the outputs of the various local controllers in the outer loop, with each local controller having a weighted output. The calculation method is as follows:

[0087]

[0088] In the formula:

[0089] e(k,t)=min{e1(k,t),e2(k,t),...,e n (k,t)}.

[0090] After this application had been running internally for a period of time, the beneficial aspects reported by on-site technicians were:

[0091] The implementation of automatic switching technology can effectively reduce manual operation, reduce the workload of personnel, reduce human error, and improve the safety factor of operating units.

[0092] Currently, the technical solution of this invention has undergone pilot testing, which is a small-scale trial of the product before large-scale mass production. After the pilot testing was completed, a user survey was conducted on a small scale, and the survey results showed that user satisfaction was high. Now, preparations have begun for the formal production and industrialization of the product (including intellectual property risk warning surveys).

Claims

1. A device for automatic switching between dry and wet states in a 600MW supercritical boiler, characterized in that: The system includes a controller, a water storage tank, a steam-water separator, a 361 valve, a boiler drain tank, a boiler drain pump, a drain control valve, an exhaust system, and a dry / wet switching module. The steam-water separator is connected to the water storage tank, and the water storage tank is connected to the 361 valve. The 361 valve, boiler drain tank, boiler drain pump, drain control valve, and exhaust system are sequentially connected. A barometer is installed on the steam-water separator to obtain the air pressure value. A level gauge is installed at the bottom of the water storage tank to obtain the liquid state in the tank. The barometer, level gauge, controller, 361 valve, boiler drain pump, and drain control valve are all connected and communicate with the controller. The dry / wet switching module is used for... The controller receives the air pressure value from the gas-liquid separator in the water storage tank from the barometer, and the liquid state in the water storage tank from the level gauge. When the air pressure value is within the range of 10MPa to 11MPa and there is liquid in the water storage tank, the controller generates a command to switch from dry to liquid state. When the air pressure value exceeds 11MPa and there is no liquid in the water storage tank, the controller generates a command to switch from liquid to dry state. The controller sends the command to the 361 valve, boiler drain pump, and drain control valve. The 361 valve, boiler drain pump, and drain control valve receive the command. When the command is for switching from dry to liquid state, the 361 valve is open, the boiler drain pump operates, and the drain control valve is open. When the command is for switching from liquid to dry state, the 361 valve is closed, the boiler drain pump stops, and the drain control valve is closed.

2. The device for automatic switching between dry and wet states in a 600MW supercritical boiler according to claim 1, characterized in that: It also includes a high-pressure heater, a water inlet valve, a water inlet gate, an economizer, and a water-cooled wall. The steam-water separator includes a first steam-water separator and a second steam-water separator. The high-pressure heater is connected to the economizer via the water inlet valve and the economizer via the water inlet gate. The economizer is connected to the water-cooled wall. The water-cooled wall is connected to the water storage tank via the first steam-water separator and the second steam-water separator. A pressure gauge is installed on the second steam-water separator.

3. The device for automatic switching between dry and wet states in a 600MW supercritical boiler according to claim 1, characterized in that: It also includes a management terminal, which connects and communicates with the controller, and a dry / wet switching module, which is used by the controller to send instruction information to the management terminal and facilitates monitoring by management personnel when needed.

4. The device for automatic switching between dry and wet states in a 600MW supercritical boiler according to claim 3, characterized in that: The management terminal is a fixed terminal, which is wired to the controller.

5. The device for automatic switching between dry and wet states in a 600MW supercritical boiler according to claim 3, characterized in that: The management terminal is a mobile terminal, which is wirelessly connected to the controller.

6. The device for automatic switching between dry and wet states in a 600MW supercritical boiler according to claim 3, characterized in that: The dry / wet switching module is used to manage the terminal to receive, record, and display the command information sent by the controller so that managers can view it.

Images