330mw unit full load section continuous heat supply control method and system

Abstract

The present application relates to the technical field of heat supply control of thermal power generating units, and particularly relates to a 330MW unit full load section continuous heat supply control method and system, which adopts a main steam and hot reheat steam double heat source combined heat supply cooperative control scheme, builds a parallel double heat source heat supply branch, collects unit and heat supply system parameters in real time, divides unit working conditions into high load stable working conditions, deep peak shaving variable load working conditions and shutdown idling working conditions, adopts differentiated heat source regulation and control strategies for different working conditions, optimizes steam switching logic and pressure reduction and temperature reduction device linkage response mechanism, cooperates with buffer undisturbed switching strategy and closed loop parameter correction, can eliminate heat supply vacuum period in the process of deep peak shaving of the 330MW unit and idling of the steam turbine, guarantees continuous and stable heat supply parameters in the full process from full load of the unit to shutdown of the steam turbine, realizes zero disturbance of heat supply, and solves the problem of heat supply interruption and heat supply quality decline caused by working condition change in the traditional single extraction heat supply mode.

Description

Technical Field

[0001] This invention relates to the field of thermal power unit heating control technology, and in particular to a method and system for continuous heating control of a 330MW unit at full load. Background Technology

[0002] With the large-scale grid connection of new energy power, the demand for grid peak shaving continues to rise. As the main type of unit for grid peak shaving, 330MW coal-fired heating units need to frequently participate in deep peak shaving and load-changing operation, while ensuring the continuity and stability of industrial and residential heating. Currently, existing 330MW unit heating systems generally adopt a single steam source heating mode, with extracted steam from the unit as the only heat source, and the control logic is only adapted to the unit's normal high-load stable operation conditions.

[0003] In actual operation, the existing technology has significant defects: First, when the unit is operating under deep peak shaving and load reduction, the turbine extraction steam parameters continuously decrease with the reduction of the unit load, and the heating pressure and temperature fluctuate greatly, which cannot meet the stable heating needs of heat users and is prone to problems such as reduced heating quality and insufficient heating. Second, during the unit shutdown operation and the turbine coasting stage after shutdown, the traditional single extraction steam source is completely interrupted, forming a fixed heating vacuum period. The heating system must be shut down in advance or rely on external backup heat sources for supplementary heating, which not only disrupts the continuity of heating, but also leads to frequent start-ups and shutdowns of the heating system and increased equipment wear. Third, the existing heating control logic is only designed for a single operating condition and lacks an adaptive switching mechanism for the full load range. It cannot adapt to the dynamic changes of the unit from full load operation, load shaving and peak shaving to shutdown coasting. During the switching of operating conditions, heating disturbances and parameter instability are prone to occur, which seriously affect the safety and quality of regional heating.

[0004] In summary, the existing heating control technology for 330MW units has problems such as poor adaptability to operating conditions, insufficient heating stability during deep peak shaving and shutdown, and the risk of heating interruption. It is difficult to meet the current dual operational requirements of normalized deep peak shaving of the power grid, uninterrupted heating, and high-precision and stable parameters. Summary of the Invention

[0005] The purpose of this invention is to provide a continuous heating control method and system for a 330MW unit under full load, which solves the problems of poor adaptability to operating conditions, insufficient heating stability during deep peak shaving and shutdown, and the risk of heating interruption in the existing technology. It is difficult to meet the current technical requirements of normalized deep peak shaving of the power grid, uninterrupted heating, and high-precision and stable parameters.

[0006] To achieve the above objectives, the present invention provides a method for continuous heating control of a 330MW unit at full load, comprising: S1. Construct a dual-heat-source combined heating architecture, selecting the unit's main steam and hot reheat steam as two heating sources. Each heat source is equipped with an independent pressure-reducing and temperature-reducing regulating branch, and the two branches are connected in parallel to the heating main pipe to form a dual-heat-source redundant heating system. S2. Real-time acquisition of unit power generation load, turbine operating conditions, main steam parameters, hot and reheat steam parameters, and heating header pressure, temperature, and flow parameters. Based on preset operating condition thresholds, the unit operating status is divided into high load stable operating condition, deep peak shaving and load changing operating condition, and shutdown coasting operating condition. S3. Implement differentiated dual-heat-source collaborative control logic for different operating conditions: Under high-load stable operating conditions, hot reheat steam is used as the main heat source, and the main steam heat source is kept in hot standby. Under deep peak shaving and variable load conditions, monitor the attenuation trend of hot reheat steam parameters, gradually activate the main steam pressure reduction and desuperheating branch, dynamically adjust the heat supply ratio of the two heat sources, and compensate for the deviation of heating parameters. During the coasting operation, the hot reheat steam source is cut off, and the main steam independent heating mode is activated. The steam parameters are adjusted by the pressure reducing and temperature reducing device to fill the gap in the heating steam source during the coasting stage. S4. Configure a dual heat source seamless switching logic and buffer adjustment program. During the process of heat source switching and heat supply ratio adjustment, the valve opening and desuperheating water flow of the two pressure reducing and desuperheating devices are synchronously linked and coordinated to suppress sudden changes in heating parameters. S5. Real-time acquisition of heating main pipe operating parameters, comparison with target heating parameters, and continuous correction of dual heat source ratio and pressure reduction and temperature reduction operating parameters based on parameter deviation, forming a closed-loop control to achieve continuous and stable heating throughout the entire process from full-load operation to turbine shutdown.

[0007] In step S2, the working condition determination threshold is set as follows: A unit load ≥ 165MW is considered a high-load stable operating condition; a unit load between 99MW and 165MW is considered a deep peak-shaving variable load operating condition; when the unit receives a shutdown command and the turbine speed continues to decrease and enters the coasting stage, it is considered a shutdown coasting operating condition.

[0008] The buffer adjustment procedure execution strategy in step S4 is as follows: Valves for heating branch lines to be put into operation are opened slowly, and valves for heating branch lines to be withdrawn are closed slowly to ensure a smooth transition of total heat supply from the main heating pipe.

[0009] In step S5, parameter verification is performed according to the preset heating pressure and temperature allowable range. When the actual parameters exceed the range, the ratio of the two heat sources is first adjusted, and then the flow rate of the warm water is reduced to achieve parameter correction.

[0010] The present invention also provides a continuous heating control system for a 330MW unit at full load, for executing the continuous heating control method for a 330MW unit at full load as described above. Includes: dual heat source heating module, parameter acquisition module, operating condition judgment module, collaborative control module, linkage adjustment module and closed-loop correction module; The dual heat source heating module includes a main steam heating branch and a hot reheat steam heating branch. The main steam heating branch and the hot reheat steam heating branch are connected in parallel to the heating header. Each branch is equipped with an independent pressure reducing valve, a desuperheater and a flow regulating valve. The parameter acquisition module is used to collect real-time data on unit power generation load, turbine operating status, main steam pressure and temperature, hot reheat steam pressure and temperature, heating header pressure, temperature, and flow rate, and upload this data to the collaborative control module. The operating condition determination module has a built-in operating condition determination threshold, receives data from the parameter acquisition module, identifies the current operating condition of the unit, and outputs operating condition commands. The collaborative control module connects the working condition determination module and the linkage adjustment module. According to different working condition commands, it calls the corresponding dual heat source collaborative control logic and outputs heat source switching and heat supply ratio control commands. The linkage adjustment module receives instructions from the coordination control module and synchronously controls the pressure reducing valve, desuperheater, and regulating valve of the main steam heating branch and the hot reheat steam heating branch to coordinate their actions, thereby achieving a disturbance-free switching of the heat source. The closed-loop correction module collects real-time parameters of the heating main pipe, compares them with the preset standard heating parameter range, generates deviation correction commands, and feeds them back to the collaborative control module to achieve dynamic closed-loop adjustment.

[0011] The parameter acquisition module communicates with the unit's DCS system, and the sampling period is no more than 1 second.

[0012] The collaborative control module has a built-in buffer adjustment program that outputs gradual valve control commands during the switching of the two heat sources to avoid drastic fluctuations in the parameters of the heating main pipe.

[0013] The present invention provides a method and system for continuous heating control of a 330MW unit at full load. Compared with the prior art, the present invention has the following significant advantages: 1. This invention adopts a dual heat source combined heating and coordinated control architecture of main steam and hot reheat steam, which breaks through the technical limitations of traditional single steam extraction heating of units, and constructs a full-condition redundant heating system. It completely solves the industry pain points of deep peak load attenuation of 330MW units, insufficient heating steam source during shutdown coasting, and heating interruption, and eliminates the heating vacuum period during the change of unit operating conditions.

[0014] 2. This invention, through differentiated operating condition adaptation control logic and dual heat source disturbance-free switching technology, can achieve zero disturbance in heating throughout the entire process of unit operation from full-load stable operation, deep load change peak shaving to turbine shutdown and coasting. Regardless of the unit's operating condition, it can ensure continuous stability of heating pressure, temperature, and flow parameters, and the heating quality is equivalent to the unit's normal high-load operation state, greatly improving heating reliability.

[0015] 3. This invention optimizes the linkage response mechanism of the pressure reducing and cooling device, realizing the adaptive and coordinated adjustment of the equipment during heat source switching and load adjustment. It effectively avoids problems such as fluctuations in heating parameters and pipeline impact caused by operating condition switching under traditional control methods, reduces the loss of heating pipeline and equipment, and extends the service life of equipment.

[0016] 4. This invention has a high degree of automation, requiring no manual intervention throughout the process. It can adapt to the normalized deep peak-shaving operation requirements of the power grid, ensuring the flexibility of the unit's peak-shaving while fully meeting the high-standard heating requirements for continuous industrial production and stable heating for people's livelihood. It is both economical and practical, and has extremely high value for promotion and application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0018] Figure 1 This is a flowchart of the continuous heating control method for the full load section of a 330MW unit according to the present invention.

[0019] Figure 2 This is a schematic diagram of the 330MW unit full-load continuous heating control system of the present invention.

[0020] In the diagram: 1-Dual heat source heating module, 2-Parameter acquisition module, 3-Operating condition determination module, 4-Collaborative control module, 5-Linkage adjustment module, 6-Closed-loop correction module. Detailed Implementation

[0021] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0022] Please refer to Figure 1 , Figure 1 This is a flowchart of the 330MW unit full-load continuous heating control method of the present invention. An embodiment of the present invention provides a 330MW unit full-load continuous heating control method, including: S1. Establish a dual-heat-source heating hardware architecture. Based on the original unit heating system, add a main steam heating branch, which is arranged in parallel with the original hot reheat steam heating branch. The two branches are independently equipped with pressure reducing components, temperature reducing components, and flow regulating valves. The outlets of the two branches are connected to the heating main pipe to provide a stable heat source for heat users, forming a dual-heat-source redundant heating structure.

[0023] S2. Real-time Parameter Acquisition and Operating Condition Determination. Through the unit's DCS system and high-precision sensing equipment, real-time data are collected on primary unit power generation load, turbine speed, main steam pressure and temperature, hot and reheat steam pressure and temperature, and heating header pressure, temperature, and flow rate. Preset operating condition determination thresholds: Unit load ≥ 165MW is determined as high-load stable operating condition; unit load 99MW-165MW is determined as deep peak-shaving variable load operating condition; unit triggering a shutdown command and the speed continuously decreasing to the coasting stage is determined as shutdown coasting operating condition.

[0024] S3. Dual-heat-source coordinated heating control is implemented according to different operating conditions. Under high-load stable conditions, hot reheat steam is used as the main heat source by default. The main steam branch is kept in hot standby mode, and the main steam branch regulating valve is closed. The heating main pipe parameters are maintained stable to match the normal heating load demand by adjusting the pressure and temperature of hot reheat steam alone. Under deep peak-shaving and variable load conditions, as the unit load decreases, the hot reheat steam parameters gradually decrease. The system calculates the heating parameter deviation in real time, gradually opens the main steam heating branch regulating valve, and dynamically adjusts the heating ratio of main steam and hot reheat steam. Through the complementary compensation of the two heat sources, the heating pressure and temperature are maintained within the standard range throughout the process without parameter fluctuations. During the shutdown coasting operation, the unit's extraction steam system rapidly loses pressure and its parameters drop sharply. The system immediately locks into the shutdown condition, instantly cuts off the hot reheat steam heating branch, and fully engages the main steam heating branch. By precisely adjusting the main steam pressure reduction and desuperheating water flow rate, it quickly matches the standard values ​​of heating parameters, fills the heating gap during the shutdown coasting phase, and prevents heating interruptions.

[0025] S4. Disturbance-free switching linkage control. During the switching of dual heat sources and the adjustment of the ratio, a buffer regulation program is activated to control the valves of the branch to be put into operation to open slowly and the valves of the branch to be withdrawn to close slowly. The corresponding pressure reducing and temperature reducing devices are synchronously linked to respond and adjust, ensuring that there are no sudden changes in the total flow, pressure and temperature of the heating main pipe, and achieving zero disturbance throughout the entire process of switching operating conditions.

[0026] S5. Closed-loop parameter correction. Real-time comparison of actual parameters of the heating main pipe with preset standard parameter range. If a slight deviation occurs, the control parameters such as the opening degree of the dual heat source valves and the flow rate of the desuperheating water are automatically corrected to continuously optimize control accuracy and achieve dynamic closed-loop stable control under all operating conditions.

[0027] Please see Figure 2 , Figure 2This is a schematic diagram of the 330MW unit full-load continuous heating control system of the present invention. The present invention also provides a 330MW unit full-load continuous heating control system for executing the 330MW unit full-load continuous heating control method as described above. Includes: dual heat source heating module 1, parameter acquisition module 2, operating condition judgment module 3, collaborative control module 4, linkage adjustment module 5, and closed-loop correction module 6; The dual heat source heating module 1 includes a main steam heating branch and a hot reheat steam heating branch. The main steam heating branch and the hot reheat steam heating branch are connected in parallel to the heating header. Each branch is equipped with an independent pressure reducing valve, a desuperheater and a flow regulating valve. The parameter acquisition module 2 is used to collect data on the unit's power generation load, turbine operating status, main steam pressure and temperature, hot reheat steam pressure and temperature, heating header pressure, temperature, and flow rate in real time, and upload them to the collaborative control module 4. The operating condition determination module 3 has a built-in operating condition determination threshold, receives data from the parameter acquisition module, identifies the current operating condition of the unit, and outputs operating condition commands. The collaborative control module 4 is connected to the working condition determination module 3 and the linkage adjustment module 5. According to different working condition commands, it calls the corresponding dual heat source collaborative control logic and outputs heat source switching and heat supply ratio control commands. The linkage adjustment module 5 receives instructions from the collaborative control module 4 and synchronously controls the pressure reducing valve, desuperheater, and regulating valve of the main steam heating branch and the hot reheat steam heating branch to achieve disturbance-free switching of heat sources. The closed-loop correction module 6 collects real-time parameters of the heating main pipe, compares them with the preset standard heating parameter range, generates deviation correction commands, and feeds them back to the collaborative control module 4 to achieve dynamic closed-loop adjustment.

[0028] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A method for continuous heating control of a 330MW unit at full load, characterized in that, include: S1. Construct a dual-heat-source combined heating architecture, selecting the unit's main steam and hot reheat steam as two heating sources. Each heat source is equipped with an independent pressure-reducing and temperature-reducing regulating branch, and the two branches are connected in parallel to the heating main pipe to form a dual-heat-source redundant heating system. S2. Real-time acquisition of unit power generation load, turbine operating conditions, main steam parameters, hot and reheat steam parameters, and heating header pressure, temperature, and flow parameters. Based on preset operating condition thresholds, the unit operating status is divided into high load stable operating condition, deep peak shaving and load changing operating condition, and shutdown coasting operating condition. S3. Implement differentiated dual-heat-source collaborative control logic for different operating conditions: Under high-load stable operating conditions, hot reheat steam is used as the main heat source, and the main steam heat source is kept in hot standby. Under deep peak shaving and variable load conditions, monitor the attenuation trend of hot reheat steam parameters, gradually activate the main steam pressure reduction and desuperheating branch, dynamically adjust the heat supply ratio of the two heat sources, and compensate for the deviation of heating parameters. During the coasting operation, the hot reheat steam source is cut off, and the main steam independent heating mode is activated. The steam parameters are adjusted by the pressure reducing and temperature reducing device to fill the gap in the heating steam source during the coasting stage. S4. Configure a dual heat source seamless switching logic and buffer adjustment program. During the process of heat source switching and heat supply ratio adjustment, the valve opening and desuperheating water flow of the two pressure reducing and desuperheating devices are synchronously linked and coordinated to suppress sudden changes in heating parameters. S5. Real-time acquisition of heating main pipe operating parameters, comparison with target heating parameters, and continuous correction of dual heat source ratio and pressure reduction and temperature reduction operating parameters based on parameter deviation, forming a closed-loop control to achieve continuous and stable heating throughout the entire process from full-load operation to turbine shutdown.

2. The method for continuous heating control of a 330MW unit at full load as described in claim 1, characterized in that, In step S2, the operating condition determination threshold is set as follows: A unit load ≥ 165MW is considered a high-load stable operating condition; a unit load between 99MW and 165MW is considered a deep peak-shaving variable load operating condition; when the unit receives a shutdown command and the turbine speed continues to decrease and enters the coasting stage, it is considered a shutdown coasting operating condition.

3. The method for continuous heating control of a 330MW unit at full load as described in claim 2, characterized in that, The buffer adjustment procedure execution strategy in step S4 is as follows: Valves for heating branch lines to be put into operation are opened slowly, and valves for heating branch lines to be withdrawn are closed slowly to ensure a smooth transition of total heat supply from the main heating pipe.

4. The method for continuous heating control of a 330MW unit at full load as described in claim 3, characterized in that, In step S5, parameter verification is performed according to the preset heating pressure and temperature allowable range. When the actual parameters exceed the range, the ratio of the two heat sources is first adjusted, and then the flow rate of the warm water is reduced to achieve parameter correction.

5. A continuous heating control system for a 330MW unit at full load, used to execute the continuous heating control method for a 330MW unit at full load as described in claim 4, characterized in that, include: Dual heat source heating module, parameter acquisition module, operating condition judgment module, collaborative control module, linkage adjustment module and closed-loop correction module; The dual heat source heating module includes a main steam heating branch and a hot reheat steam heating branch. The main steam heating branch and the hot reheat steam heating branch are connected in parallel to the heating header. Each branch is equipped with an independent pressure reducing valve, a desuperheater and a flow regulating valve. The parameter acquisition module is used to collect real-time data on unit power generation load, turbine operating status, main steam pressure and temperature, hot reheat steam pressure and temperature, heating header pressure, temperature, and flow rate, and upload this data to the collaborative control module. The operating condition determination module has a built-in operating condition determination threshold, receives data from the parameter acquisition module, identifies the current operating condition of the unit, and outputs operating condition commands. The collaborative control module connects the working condition determination module and the linkage adjustment module. According to different working condition commands, it calls the corresponding dual heat source collaborative control logic and outputs heat source switching and heat supply ratio control commands. The linkage adjustment module receives instructions from the coordination control module and synchronously controls the pressure reducing valve, desuperheater, and regulating valve of the main steam heating branch and the hot reheat steam heating branch to coordinate their actions, thereby achieving a disturbance-free switching of the heat source. The closed-loop correction module collects real-time parameters of the heating main pipe, compares them with the preset standard heating parameter range, generates deviation correction commands, and feeds them back to the collaborative control module to achieve dynamic closed-loop adjustment.

6. The 330MW unit full-load continuous heating control system as described in claim 5, characterized in that, The parameter acquisition module communicates with the unit's DCS system, and the sampling period is no more than 1 second.

7. The 330MW unit full-load continuous heating control system as described in claim 6, characterized in that, The collaborative control module has a built-in buffer adjustment program that outputs gradual valve control commands during the switching of the two heat sources to avoid drastic fluctuations in the parameters of the heating main pipe.

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